a chronology of progress,

A CHRONOLOGY OF PROGRESS,1967-1980

IntroductionThis section presents a year-by-year sum-

mary of progress in smallpox eradication (Fig .10.4) to provide a frame of reference for thechapters describing the eradication pro-grammes in individual countries or groups ofcountries (Chapters 12-23) and the certifica-tion of eradication (Chapters 24-27) .

In compiling the data on the incidence ofsmallpox over the years, we have reviewed theavailable and sometimes conflicting reportsand have made use of the figures that in ouropinion most accurately reflect the situationat the relevant time. Some figures differ fromthose previously published and from those inthe official national and international records .The differences are greatest for the early yearsof the programme, when notifications ofreported cases were most delayed and incom-plete. The reader who wishes to refer to thecontemporaneous figures may consult theWeekly epidemiological record, which provided acompilation of the most recent informationevery 2-3 weeks and a summary of the statusof the programme as a whole twice a year .

Throughout the course of the IntensifiedSmallpox Eradication Programme, particularimportance was attached to defining whichcountries had endemic smallpox and whichdid not. Although this might seem a straight-forward task, it was not so, especially duringthe first few years and for the smallercountries. The first summary of the situationin this period was provided in a report by theDirector-General of WHO to the forty-firstsession of the Executive Board, which metin January 1968 . In that report, 29 countriesor territories were identified as being "ende-mic" (30 if East Pakistan, which later becameBangladesh, and West Pakistan are consideredseparately) . Later information led to Cam-eroon, Southern Rhodesia and Yemen beingadded to the list ; each had reported only a fewcases in 1967 and these were at first assumedto represent importations, but they were not .However, 2 small countries Lesotho andSwaziland-were mistakenly shown as hav-ing endemic smallpox in 1967 because of theirproximity to infected areas in South Africaand their rudimentary reporting systems .Subsequent information suggests that bothwere smallpox-free . In later years, othercountries were mistakenly identified as non-endemic because of government suppression

10. THE INTENSIFIED PROGRAMME, 1967-1980

517

of smallpox notifications . This occurred forIran from 1970 to 1972, for Iraq from 1971 to1972 and for Somalia in 1976. Later informa-tion received from government and othersources served to clarify the situation .

The Situation at the Start of the IntensifiedProgramme, 1967

The first year of the Intensified SmallpoxEradication Programme saw a substantialacceleration of activities compared with pre-vious years. This was primarily the conse-quence of greater financial resources andmore staff becoming available from WHOand of the implementation of the regionalprogramme in western and central Africa thatreceived direct support from the USA . Cer-tainly this enhanced effort started none toosoon, for the number of reported cases ofsmallpox in the world rose in 1967 to 131 776,one of the highest totals for a decade . Little ofthis increase can be attributed to betterreporting since few countries had yet im-proved their case-notification procedures . In-deed, it soon became evident that reportingwas even less complete than had been feared ;it had been thought that perhaps 1 case in 20was being notified, but experience in the fieldbegan to indicate that a figure of 1 in 100 wasprobably nearer the mark .

The 31 countries or territories classified ashaving endemic smallpox (see box) were in 4epidemiological zones sufficiently separate tomake it unlikely that if one was freed fromsmallpox, it would become reinfected fromanother. These were : (1) Brazil, (2) Indonesia,(3) Africa south of the Sahara, and (4) acontiguous group of southern Asian countriesextending from Afghanistan through WestPakistan, India and Nepal to East Pakistan .The eastern borders of East Pakistan andIndia were taken as the eastern limit ofendemic smallpox on the Asian mainland,although Burma had imported cases from1967 to 1969 . The People's Republic of Chinawas not in relations with WHO in 1967 andprovided no official information, but reportsby visitors suggested that smallpox was notpresent there ; the government confirmed thisin 1973 .

Programme implementation

Basic strategies and principles were issuedin July in a WHO Handbook for SmallpoxEradication in Endemic Areas, and these wereendorsed in September by the WHO Scienti-

518

SMALLPOX AND ITS ERADICATION

fic Group on Smallpox Eradication . Surveil-lance reports giving epidemiological infor-mation and documenting progress in thecountries were widely distributed by WHOfrom September on .

WHO gave priority to the eradicationprogrammes in the smaller of the major epi-demiological zones-Brazil and Indonesia-in the expectation that success there wouldfree resources that could be concentratedon the larger and probably more difficultzones. Brazil's programme had started in1966, and Indonesia and WHO agreed inDecember 1967 on one to start in 1968.Eradication programmes began or were underway in 12 of the other 29 endemic countries atthe end of 1967 . Programmes in Cameroon,Dahomey, Ghana, Mali, Niger, Nigeria, Togoand Upper Volta were included in the region-al western and central Africa programmesupported by the USA ; a programme in theDemocratic Republic of the Congo startedlate in the year ; and WHO-supported pro-grammes were continuing in Afghanistan,Nepal and Zambia, although only the last ofthese represented a meaningful effort .

Many other countries decided to undertakeprogrammes and developed plans of opera-tions with advice from WHO ; the procure-ment of supplies began as each plan wasfinalized . In India, however, a serious prob-lem was posed by the government's decisionin December 1966 to terminate its 5-year-oldvaccination campaign. That country was thenreporting more than one-third of the world'scases. Appealed to by WHO, it agreed that ajoint India-WHO team should undertake afield assessment of the situation late in 1967and develop an alternative plan .

Other developments

In May the first annual meeting of WHOregional and Headquarters officers respon-sible for smallpox eradication was held todiscuss and agree upon plans, needs andpriorities. In December there was held inThailand the first of many intercountrymeetings at which the staff of programmes indifferent countries and their WHO counter-parts exchanged experiences and debatedstrategies .

The supply of potent, stable vaccine beingcrucial to success, arrangements were madefor laboratories in Canada and the Nether-lands to test vaccines and to help countries todevelop their own production . At the sametime, WHO initiated a survey of the vaccinequality and production capacity of labora-tories throughout the world. More than 200batches of vaccine were tested underWHO's auspices in 1967 (43 batches in 1966,12 in 1965). All countries were asked tocontribute vaccine and by the end of the year15 million doses had been distributed byWHO, 4 times as many as in 1966. Over andabove this, the USSR provided more than 75million doses, mainly to Afghanistan, Indiaand Burma, and the USA about 25 milliondoses for use in Africa .

After trying and rejecting several cheapervariants of the jet injector, which had comeinto operational use in 1967, WHO assessedthe capability of the bifurcated needle-a newdevice by which a very small amount ofvaccine could be introduced almost painlesslyinto the skin by multiple punctures . By theend of the year it had proved to be theinstrument of choice .

Countries or Territories with Endemic Smallpox in January 1967

Africa, eastern and southern : Burundi, Democratic Republic of the Congo (Zaire from1971), Ethiopia, Kenya, Malawi, Mozambique, Rwanda, South Africa, SouthernRhodesia (Zimbabwe from 1980), Uganda, United Republic of Tanzania, Zambia .

Africa, western and central : Cameroon, Dahomey (Benin from 1975), Ghana, Guinea,Liberia, Mali, Niger, Nigeria, Sierra Leone, Togo, Upper Volta (Burkina Faso from1984) .

Americas : Brazil .

Asia : Afghanistan, East Pakistan (Bangladesh from 1971) India, Indonesia, Nepal,Pakistan (West Pakistan until 1971), Yemen.

None

Transmission InterruptedWestern & central Africa: Ghana

ImportationsAfrica: Botswana, Chad, Cbte d'lvoire, Lesotho,SudanAmericas: ArgentinaAsia: Bhutan, Burma, Kuwait, Sikkim, Sri Lanka,United Arab EmiratesEurope : Czechoslovakia, Federal Republic ofGermany, United Kingdom

uv000Mw

55 000

10 000

x0a.E0v 1000

100

10


Plate 10.42. Smallpox in the world, 1967 : endemicity in 31 countries or territories .

519

520

The Situation in 1968

During the second year of the IntensifiedProgramme, the number of endemic coun-tries with special eradication programmesincreased from 12 to 19, and agreements werereached or appeared imminent for the com-mencement of programmes in 8 others.However, 4 remained as problems-SouthernRhodesia, South Africa, Mozambique andEthiopia . The first two, with which WHOhad no official contact, caused little immedi-ate concern as they reported few cases and hada reasonably extensive health infrastructure.However, civil war in Mozambique precludedan extensive programme there, and Ethiopiadeclined to initiate a programme .

The number of countries with endemicsmallpox in 1968 remained at 31, transmis-sion having stopped in Ghana in 1967 butSudan becoming infected following importa-tions from Ethiopia. The number of reportedcases diminished from 131 776 to 79 951 butthis was almost entirely accounted for by adecrease in India (from 84 902 to 35 179cases). Whether this represented better small-pox control in India or simply a longer-termcyclical trend in the incidence was unknown .

AfricaThe most heartening progress was made

in the regional programme in western andcentral Africa, which included some of theworld's poorest and most heavily infectedcountries. By the end of 1968, 62 millionpersons had been vaccinated-almost 60% ofthe total population ; in September specialsurveillance-containment programmes beganin many of the countries. There was a sharpdrop in the number of cases reported and 6of the 10 remaining endemic countries inter-rupted transmission . However, civil war inNigeria, the most populous country, threat-ened to extend throughout the country .In eastern and southern Africa, Ugandaand Zambia also stopped transmission .

South AmericaBrazil, the only endemic country in the

Americas, made notable progress in its vacci-nation campaign and, by the end of the year,was vaccinating 1 .3 million persons eachmonth. There was little improvement, how-ever, in the notifications or the surveillanceprogramme . Neighbouring countries in


South America also conducted vaccinationcampaigns but cases-all due to importationsfrom Brazil-were detected only in FrenchGuiana and Uruguay .

Asia

The programme in Indonesia began in1968 and within 6 months transmission wasinterrupted throughout East Java, a provincewith more than 25 million persons . Althoughspecial vaccination campaigns were begun orintensified throughout Indonesia and otherendemic Asian countries, progress was gener-ally poor and reporting was little improved .

Other developmentsThe lack of attention to surveillance was a

matter of special concern and surveillance wasstressed as being "as important as the vaccina-tion programme itself" at the Twenty-firstWorld Health Assembly in May and empha-sized again at an intercountry seminar inKinshasa in November. Special training ma-terials were developed to foster an under-standing of the principles and methodsinvolved .

The bifurcated needles, introduced for gen-eral use, alleviated some shortages of vaccine,but it became apparent that the endemiccountries would soon need to producemuch more vaccine. WHO convened expertsin vaccine production to develop a manualon production methodology, and the Organi-zation sent consultants to 24 laboratories andprovided equipment and reagents to 30 .

The dissemination of information aboutthe programme and about field observationswas facilitated as reports about the pro-gramme began to be published every 2-3weeks in the Weekly epidemiological record fromMay onwards and other documents weredistributed regularly to senior eradicationstaff throughout the world .

Activities during the first 2 years of theIntensified Programme laid a sound founda-tion but how this could be built upon in thefield was uncertain . Although the progress inwestern and central Africa was encouraging,the resources made available there by the USAwere greater than could then be foreseen forother countries ; progress elsewhere was madeprimarily in the countries with the moreadvanced health services. At the end of 1968,the feasibility of global smallpox eradicationwas by no means certain.

Sudan

Transmission InterruptedEastern & southern Africa : Uganda, ZambiaWestern & central Africa : Cameroon, Guinea,Liberia, Mali, Niger, Upper Volta

ImportationsAfrica : Chad, GhanaAmericas: French Guiana, UruguayAsia : Burma, United Arab EmiratesEurope : Belgium, United Kingdom

a0

0

0w 1000

vv000v

55 000

10 000

100

10


Plate 10.43. Smallpox in the world, 1968 .

521

522


Certain evidence of progress came duringthe third year of the Intensified Programme .Only 23 countries recorded endemic casesthat year-8 fewer than in 1968-and in 5 ofthem transmission was interrupted . Thus,during a period of only 3 years, 15 countriessuccessfully eliminated smallpox . Except forYemen, they were all in Africa, and 10 ofthem were in western and central Africawhere, at the end of 1969, smallpox persistedonly in northern Nigeria . Kenya and Mozam-bique also ceased to report cases but becausesurveillance was inadequate there, the absenceof cases was viewed with scepticism at first .

Although improved notification proce-dures led to more complete reporting inseveral countries, the total number of casesreported in the world declined to 54 199, thelowest figure that had ever been recorded .The optimism this gave rise to was tempered,however, by the realization that none of thecountries in which transmission had beenstopped was large, only Kenya having apopulation of as many as 10 million persons .

AfricaThe successes in Africa were encouraging

but 4 of the largest countries still presentedserious problems. The programme in theDemocratic Republic of the Congo pro-gressed well but the country was one of thelargest in Africa, transport presented formid-able problems and smallpox was prevalenteverywhere . In the Sudan, smallpox spreadwidely after being imported and civil warthroughout its southern provinces made acti-vities impossible there. In November, Ethio-pia, which presented the greatest logisticchallenge, reluctantly agreed to a programmebut it could not begin until 1971 . AboutSouth Africa, little was then known exceptthat the number of reported smallpox casesincreased from 43 in 1967 to 246 in 1969 .

South America

Brazil intensified its vaccination campaignand began surveillance programmes in 4states. Because of this, notifications improvedand the number of reported cases increased,from 4372 in 1968 to 7407 cases in 1969 . Nearthe end of the year, however, the principalsurveillance officers were discharged and thedirector of the programme resigned .


AsiaThe programmes in Afghanistan, Indone-

sia and Nepal were substantially strengthenedduring 1969 but there was little progress toreport in either India or Pakistan . Massvaccination campaigns in East and WestPakistan were far behind schedule and sur-veillance activities were nominal, at best .India postponed the signing of an agreementto strengthen its programme and, in 1969,reported more births than primary vaccina-tions . India's decision that year to begin usingthe bifurcated needle and to terminate the useof liquid vaccine was almost the only encour-aging news from a country which each yearcontinued to report one-third to one-half ormore of the world's cases of smallpox .

Other developmentsVaccine production increased in a number

of the endemic countries in 1969, but short-ages could be foreseen as the year progressedand more programmes began . Despite appealsfor additional donations of vaccine, the quan-tities contributed in 1969 were smaller thanin 1968 .

The attainment of global eradication restedon the premise that there was no animal orother natural reservoir of the virus, but firmerevidence of this was required . In March 1969,the first of a series of biennial meetings ofan informal group of research workers wasconvened by WHO in Moscow to planand implement a collaborative research pro-gramme to discover whether any reservoir ofvariola virus existed and to elucidate thebehaviour of the closely related monkeypoxvirus.

The promotion of surveillance-contain-ment activities continued to meet with limit-ed success and so the Director-General pre-sented a special report to the WHO ExecutiveBoard which recommended for every countrythe "immediate investigation of every reported case ofsmallpox by trained investigators, the tracing of thesource of infection and the prompt application ofcontainment measures" . In May, a seminar for thecountries of western and central Africa pro-vided important documentation of this ap-proach, and another, held in Pakistan inNovember, for participants from 11 countriesof the Eastern Mediterranean and South-EastAsia Regions, stressed its importance . Trans-lation of the methods into practice, however,continued to progress slowly .

55 000

10 000

00.bE

0 1 000dAW000.d

100

10


Plate 10 .44. Smallpox in the world, 1969 .

Smallpox re-establishedNone

Transmission InterruptedAsia: YemenEastern & southern Africa : Kenya, MozambiqueWestern & central Africa: Dahomey, Sierra Leone,Togo

ImportationsAfrica: Cameroon, Mali, Niger, UgandaAmericas : UruguayAsia : Burma

523

524


Developments in 1970 gave grounds forgenuine optimism that global smallpox eradi-cation could be achieved : only 18 countriesrecorded endemic cases during the year and in6 of these transmission was interrupted-5 inAfrica and 1 in Asia . Large populations wereinvolved. With the containment of the lastcases in Nigeria in May, more than 100million persons in western and central Africawere in a smallpox-free region. Wholly unex-pected was the elimination of smallpox fromthe densely populated area of East Pakistan(population in 1970, almost 66 million)following a brief but effective surveillance-containment programme . The reported casesof smallpox in the world during 1970 num-bered only 33 693, a decrease of 38 % from therecord low of the previous year .

Africa

At the end of 1970, smallpox was consi-dered to be endemic in only 5 countries in thewhole of Africa : the Democratic Republic ofthe Congo, Ethiopia, Malawi, South Africaand the Sudan. Excellent progress was madein the Democratic Republic of the Congoduring the year and South Africa embarkedon a special vaccination campaign . Sudan'sprogramme, however, progressed slowly inthe accessible areas and nothing could yet bedone in the strife-ridden southern provinces .Ethiopia's programme had not yet started,and the epidemiological situation in Malawiwas unclear .

South America

The increased incidence of smallpox re-ported during 1969 had brought additionalresources and support to Brazil's programme ;its vaccination campaign accelerated and bythe end of 1970 it appeared to be on the vergeof interrupting transmission . Programmes inother countries were proceeding adequatelyand only 1 outbreak was detected, in anArgentinian town on the Brazilian border .

Asia

Indonesia conducted a successful surveil-lance-containment programme and esti-mated that by the end of the year 85% ofits population resided in smallpox-free areas .Although transmission had been interrupted


in East Pakistan and programmes in Afghan-istan and Nepal were progressing well, thosein India and West Pakistan were not . In WestPakistan, a poorly conducted mass vaccina-tion campaign lagged far behind schedule .India agreed to strengthen its national struc-ture with WHO assistance, but otherwiseremained confident as the number of reportedcases continued to decrease, only 12 773 casesbeing reported in 1970 compared with 84 902cases in 1967. Late in the year, however, itbecame evident that this was partly an artifi-cial decrease, changes in the national notifica-tion system serving to inhibit reporting .

To encourage surveillance-containmentactivities in Asia, a seminar was held in NewDelhi in December 1970 for countriesthroughout the South-East Asia Region.West African and Indonesian staff describedtheir successes with this strategy but fewchanges followed .

A significant event, although it was notrecognized until a year later, was the reintro-duction of endemic smallpox into Iran. Majorepidemics were to follow, with spread of thedisease to neighbouring countries and even-tually to Europe.

Other developments

With more eradication programmes inprogress, increasing resources were required .Efforts to obtain additional donations metwith little success, and an attempt to haveWHO funds that were available in the Ameri-cas reallocated for use in Asian countries alsofailed. Vaccine was short throughout 1970and donated vaccine frequently had to bedispatched on the very day it was received inGeneva. Towards the end of the year, itbecame apparent that it would be far moredifficult to eradicate smallpox from the re-maining endemic countries than it had beenin those which had already been freed of thedisease.Another unexpected problem occurred

when, in the second half of the year, humancases of monkeypox, clinically indistinguish-able from smallpox, were discovered inLiberia, Sierra Leone and Zaire . Althoughmonkeypox was not caused by the variolavirus, the question arose whether it mightbehave like smallpox and be sustained byhuman-to-human spread . Extensive field andlaboratory investigations began immediatelybut not until the late 1970s could the fears befully allayed .

040wal

.j

i

Transmission InterruptedAsia : East PakistanEastern & southern Africa : Burundi, Rwanda,Southern Rhodesia, United Republic of TanzaniaWestern & central Africa: Nigeria

ImportationsAfrica : Uganda, ZambiaAmericas : ArgentinaAsia: Saudi Arabia, United Arab EmiratesEurope : Denmark, Federal Republic of Germany,Norway

x0abE

0d 1000uvw0

0 .d

55 000

10 000

100

10

10. THE INTENSIFIED PROGRAMME, 1967-1980 525

Plate 10 .45. Smallpox in the world, 1970 .

526


The fifth and sixth years of the IntensifiedProgramme, 1971 and 1972, were years oftransition between the remarkably successfulperiod 1967-1970-when smallpox was suc-cessfully eliminated from large areas of theworld with few resources-and the succeed-ing years, 1973-1977, when ever larger re-sources and more heroic measures were re-quired to stop transmission in the fewremaining endemic countries. In some partsof the world remarkable progress was madeduring 1971, but in others there were setbacksand portents of future problems . The year1971 began with endemic smallpox in 12countries, 4 of which interrupted transmis-sion during the year, but 2 others becamereinfected-Botswana and Iraq . For the firstyear since the programme began, the numberof reported cases increased, from 33 693 in1970 to 52 807 in 1971 .

Americas

In April, the last cases in Brazil, and in theWestern Hemisphere, were detected . Thus,the first of the 4 major epidemiological zonesbecame smallpox-free . A plan of work wasimmediately developed for investigations andreports that would permit the certification oferadication after 2 years .

Africa

After transmission had been interruptedduring the year in Malawi, South Africa andZaire (formerly the Democratic Republic ofthe Congo), smallpox was endemic in only3 African countries at the end of 1971-Ethiopia, the Sudan and Botswana (where itspread widely after having been reintroducedjust as the last cases were occurring in SouthAfrica). The programme that started in Ethi-opia in 1971 found smallpox to be a far greaterproblem than had been expected . A staff offewer than 80 persons detected 26 329 cases,compared with the 722 cases reported in 1970.In the Sudan, smallpox continued unabated inthe southern provinces affected by civil war .It was apparent that eradication throughoutAfrica would need a greatly intensified effort,accompanied by a measure of good fortune, tosurmount the problems of civil war .

Asia

In Asia, too, both successes and setbacksoccurred . The programmes in Afghanistan,Indonesia and Nepal progressed so satisfacto-


rily that, by the end of the year, each appearedto be on the verge of eliminating smallpox .One western state of India (Gujarat), whichhad been reporting 10% of the world's cases,mounted a highly effective surveillance-containment programme and succeeded instopping transmission within a year . Epi-demic smallpox, however, erupted in adjacentIndian states and, there, satisfactory pro-grammes were slow to begin. During 1971,civil war in smallpox-free East Pakistan(which became Bangladesh in December)caused some 10 million refugees to flee toIndia, where most of them were housed inspecial camps in areas in which smallpox wasprevalent. Although all persons were sup-posed to be vaccinated on arrival, this precau-tion was not taken in several camps, includingone of the largest . There, smallpox broke outat the end of the year and spread throughoutthe camp. In West Pakistan, an unsatisfactoryprogramme was further compromised whenthe country was divided into 4 largely autono-mous provinces and separate programmes hadto be re-established in each .

It was in the course of 1971 that thepresence of smallpox in Iran first becameknown through numerous unofficial reports,and the government eventually acknowl-edged that 29 cases had occurred, all of whichwere said to have been importations . Muchlater, it was learned that smallpox had infact been introduced from Afghanistan inOctober 1970 and that hundreds of caseshad occurred in 1971 . Subsequently, it wasdiscovered that the disease had also spreadto Iraq in November 1971 .

Other developments

Sufficient progress had been made in eradi-cation to cause the authorities in both theUnited Kingdom and the USA to cease theirprogrammes of routine vaccination in 1971 .However, a WHO Expert Committee onSmallpox Eradication, convened in Novem-ber, presciently observed that "an effort atleast equal to that made in the past 5 years"would be required to interrupt transmission inthe remaining endemic areas . Although fewcountries were now involved, they poseddifficult problems. To encourage nationalgovernments and their smallpox personnel,the WHO Headquarters staff began to spendan increasing amount of time in the field, butadditional resources were not forthcomingand vaccine remained in critically shortsupply .

M Endemic

Smallpox re-establishedBotswana, Iraq

Transmission InterruptedAmerica : BrazilEastern & southern Africa: Malawi, South AfricaWestern & central Africa : Zaire

ImportationAfrica : Djibouti, Kenya, UgandaAsia: United Arab Emirates

55 000

10 000

1000

100

10


Plate 10.46. Smallpox in the world, 1971 : eradication from Brazil .

527

528


Like the preceding year, 1972 was markedby notable successes and unexpected setbacks .Overall, the progress was encouraging. Therewere 10 endemic countries as the year began,but transmission was stopped in 5 of them inthe course of the year . Successes in 3 of these-Afghanistan, Indonesia and the Sudanrepresented exceptional achievements. Theother 2 were Iran and Iraq, for which the truesituation was not known with certainty untila year later. The number of cases of smallpoxrecorded in the world as a whole increased forthe second successive year-65 140 cases in1972 compared with 52 807 cases in 1971-but reporting was more complete and, by thesummer, surveillance programmes of somesort were in place for the first time in allcountries .

During the first quarter of the year, how-ever, 3 serious problems emerged . In Febru-ary, epidemics of smallpox began to spreadacross the newly independent country ofBangladesh as refugees returning from campsin India brought the infection with them . InMarch, Iraq and the Syrian Arab Republicofficially acknowledged the presence ofsmallpox and soon thereafter a major out-break occurred in Yugoslavia, imported fromIraq. Finally, in April, a WHO epidemiolo-gist, on arrival in Botswana, confirmed thatsmallpox had already spread widely there .

Despite these problems, the geographicalextent of the infected areas continued todiminish and it was proposed that "the finalphase" should begin in September, the objec-tive being a nil incidence by June 1974 .Intercountry seminars were held in Ethiopia(September), India (November) and Pakistan(November) to launch this special effort,referred to for the first time as "Target Zero"in an issue of the WHO magazine World healthand in the first of a series of fortnightlyreports circulated by the WHO SmallpoxEradication unit .

AfricaThe progress in 1972 in the 3 endemic

African countries exceeded expectations . Inthe Sudan, the civil war in the southernprovinces ceased and an effective surveil-lance-containment programme succeeded ininterrupting transmission in December, morethan a year earlier than WHO staff hadexpected. Botswana rapidly mobilized itsresources and by the end of the year theinterruption of transmission seemed immi-


nent. As Ethiopia's programme gainedmomentum, the number of reported casesdecreased by 35%, from 26 329 in 1971 to16999.

Asia

The second of the world's major epidemi-ological zones became free of smallpox inJanuary, when transmission ceased in Indone-sia. This was achieved in less than 4 years andwith only a modest amount of internationalassistance . Afghanistan, where formidablegeographical and cultural problems werecompounded by the practice of variolation,had once been thought the country in whichattempts to eradicate smallpox were the leastlikely to succeed . Yet it recorded its lastendemic cases in October. These successesprovided some much-needed encouragementto the other endemic countries of Asia, whosesituation was very different . Emergency assis-tance had been promptly provided to Bangla-desh to stem the epidemic of imported casesbut, in the post-war chaos, the health serviceswere unable to cope . More than 10 000 caseswere recorded, but it is estimated from laterstudies that more than 100 000 cases occurred .During the autumn, major epidemics beganalong the densely populated Indo-Gangeticplain in southern Pakistan, India and centraland western Bangladesh . Because of the verylarge numbers of health staff in the Asiancountries and the greater interest in eradica-tion taken by the national authorities, hoperemained high that the problems might yet besurmounted, but far more serious difficultieswere to develop .

Other developments

An epidemic in Yugoslavia, the first in thatcountry for 41 years and one of the largest inEurope since the Second World War, remind-ed donor countries of the severity of thedisease and emphasized the importance ofglobal smallpox eradication . Increased dona-tions of vaccine were received and the debateat the Twenty-fifth World Health Assemblywas the most extensive ever, praise for theachievements being mingled with expressionsof concern about setbacks in Bangladesh,Botswana and western Asia . Despite thesentiments expressed, however, voluntaryfinancial contributions remained at much thesame level as before and WHO evendecreased its regular budget allocation for theprogramme for the following year.


0 Q

Smallpox re-establishedBangladesh

Transmission InterruptedAsia: Afghanistan, Indonesia, Iran, IraqEastern & southern Africa: Sudan

ImportationsAfrica: Djibouti, Somalia, South Africa, UgandaAsia : Saudi Arabia, Sri Lanka, Syrian Arab RepublicEurope : Federal Republic of Germany, Yugoslavia

Plate 10.47. Smallpox in the world, 1972 : eradication from Indonesia .

5 29

530


The year 1973 marked the beginning of agreatly intensified effort, which steadily in-creased in tempo from the autumn . As theyear began, only 6 endemic countries re-mained. Among these, Botswana recordedonly 27 cases before successfully stoppingtransmission in November and Nepal re-ported 277 cases, almost all of which could beshown to have occurred following importa-tions from India. Although the other 4countries (Bangladesh, Ethiopia, India andPakistan) reported large numbers of cases,large areas within each of them were free ofsmallpox or nearly so. It was calculated that90% of all cases in 1973 occurred over only10% of the land area of the 4 countries .

Asia

During the first 6 months of the year, thenumber of cases reported in Asia rose sharply .Although some of this increase was thoughtto represent more complete notification ofcases, surveillance was still by no means fullysatisfactory anywhere and epidemics werebeing discovered of a size not seen since thebeginning of the Intensified Programme . Bythe end of June, almost 83 000 cases hadbeen reported, including some 49 000 inIndia, 27 000 in Bangladesh and 6000 inPakistan-totals which were all higher thanduring the comparable period in 1972 .

For these countries, it appeared that adifferent strategy would be required to elimi-nate smallpox. The comparatively simplemeasures for case detection and containmentwhich had previously been effective in Africawere proving inadequate in Asia. The solu-tion proposed was to detect cases morepromptly so that they could be containedbefore further spread occurred . In July, there-fore, Indian and WHO staff decided tomobilize all health staff in India to undertake1-week, village-by-village searches in Octo-ber, November and December in the 4 stateswhich were then reporting 93% of allcases. In other Indian states 1 or 2 searcheswould be conducted during this 3-monthperiod. A similar effort was decided upon inPakistan . The hope was to eliminate mostsmallpox foci during the autumn, whensmallpox spread slowly, and thus to preventwidespread dissemination during the periodof rapid transmission from January to April . Ifthis was successful, it was believed that


smallpox could be eliminated during thesummer of 1974. In Bangladesh, many addi-tional surveillance teams were provided tosearch for smallpox in schools and markets .

The results were encouraging in Bangla-desh and Pakistan, each country reportingan incidence similar to that of the year beforedespite much more intensive surveillance . InIndia, however, more than 30 000 cases werediscovered between October and December,almost 5 times as many as had been foundduring the same period in 1972 and, indeed,more cases than had been reported in thewhole country during any of the 4 precedingyears. The numbers were scarcely believablebut the eradication programme staff contin-ued to be optimistic because of the commit-ment of government officials, the extent ofactivity and the interest of the health staffs .

AfricaEthiopia remained the only endemic

country in Africa and there, as in Asia, moreintensive measures were taken through theaddition of staff and the provision of helicop-ters to help cope with the rugged terrain . Thenumber of reported cases continued to declinedespite more complete notifications but logis-tic difficulties were increasingly exacerbatedby mounting civil unrest .

Other developmentsDuring 1973, the first of the international

commissions for the certification of eradica-tion examined the programmes in the Ameri-cas and confirmed that smallpox had beeneradicated from the Western Hemisphere .

A new concern emerged, however, about apossible natural reservoir of smallpox . Thisarose from the isolation-from monkey kid-ney tissue cell cultures in the Netherlands andfrom animal specimens collected near mon-keypox cases in Zaire-of what were termed"whitepox" viruses, which were indistin-guishable from smallpox virus. The WHOinformal research group held its third bien-nial meeting in 1973 and developed a newagenda of work, but not for several yearswas this concern finally laid to rest and the"whitepox" viruses shown to be inadvertentlaboratory contaminants.

During 1973, the number of recorded casesin the world-135 904-was the highest for15 years, but the ultimate goal, "Target Zero",appeared none the less to be just over thehorizon .

Endemic

L- 1 Smallpox re-establishedNone

ImportationsAfrica : Djibouti, Kenya, SomaliaAsia: Afghanistan, Bhutan, Japan, SikkimEurope: United Kingdom

55 000

10 000

100

10



531

532


Throughout 1974, the programme as awhole steadily grew in intensity and acceler-ated in tempo. Successes in the 1973 autumncampaigns had encouraged the belief that aconcerted effort of no more than 6-12 monthswould see the realization of global smallpoxeradication . Additional national and interna-tional personnel as well as increased quanti-ties of supplies and equipment supported thiseffort. It was concentrated on the shrinkingendemic areas which in aggregate weresmaller than the land area of Pakistan, one ofthe 5 countries concerned . With eradicationapparently imminent, programme staffworked feverishly, driven partly by the fearthat unanticipated natural or man-made catas-trophes might thwart the achievement justshort of the goal . Indeed, this concern provedwell founded in 4 of the 5 countries .

Asia

In India, during the first 3 months of theyear, intensified search programmes result-ed in much more complete reporting but nomore cases than in 1973 . In May, however,explosive epidemics began, nearly 50 000cases being detected that month and the worstaffected state (Bihar) reporting more than8000 cases in a week . Work was severelyhampered by petrol shortages as well as bystrikes which immobilized rail and air trans-port. Bihar State was further affected bydevastating floods in the north, severedrought in the south, and civil disorder . Thesedifficulties were compounded by a majorepidemic in an urban industrial centre whichresulted in the spread of smallpox to hundredsof distant villages in India and Nepal .

In Pakistan and Bangladesh, other prob-lems occurred . Surveillance in Pakistan's lar-gest province (Punjab) was suspended prema-turely by over-optimistic provincial healthauthorities and an undetected epidemic in itscapital, Lahore, quickly spread throughoutthe province . Bangladesh decided to restruc-ture the health care system, resulting in thesuspension of most activities, including thosefor smallpox, for many weeks. In the summer,monsoon rains brought the worst floods formany years to northern Bangladesh, displac-ing tens of thousands of persons .

During the first 6 months of 1974, morecases were recorded in Asia than had beenreported annually throughout the world for


more than 15 years. By June, however, greatlyexpanded and better organized programmeswere functioning and progress began to bemeasured in terms of the numbers of existingoutbreaks (villages or town areas in which 1case or more had occurred in the preceding 4weeks). Asia had 8086 outbreaks in June .

Throughout the hot summer monsoonperiod, all staff were urged to maintain thepace of their work in order to take the fullestadvantage of the seasonal decline in incidence .The effort proved successful. Pakistan detect-ed its last case in November, and by the end ofthe year there were only 517 known outbreaksin all of Asia.

There was optimism that transmissionwould be interrupted by the summer of 1975 .The only doubtful areas were those in whichrefugees were crowded in Bangladesh . Thenumber of outbreaks in that country, whichhad been only 78 at the end of October, hadtripled by the end of December. More thanhalf, however, consisted of only 1 or 2 casesand hope persisted that, with the plannedaddition of health staff and temporaryworkers, the problem could be managed .

Africa

As more support became available, theprogramme in Ethiopia made steady progressin many areas of the country. The number ofreported cases decreased from 5414 in 1973 to4439 despite more complete notifications ; inDecember, only 166 cases were discovered . Inincreasingly large areas of the country, how-ever, field operations were severely hamperedby the revolution that led to the deposition ofthe Emperor, by hostilities with Somalia inthe Ogaden desert, and by the insurrection inEritrea .

Other developmentsThe eradication of smallpox from Indone-

sia was certified by an international commis-sion in April, but certification elsewhere wasdeferred pending further progress in Africaand Asia. Increasing efforts were made torecruit suitable international staff and consul-tants for the intensified campaign and toobtain sufficient contributions of vaccine andfunds to permit the work to be sustained. Atthe end of the year WHO, for the first time,convened a meeting of potential donors torequest contributions of US$3 .3 million, butonly US$2.1 million were pledged .

55 000

10 000

1 000

100

10


Endemic

® Smallpox re-establishedNone

Transmission InterruptedAsia : Pakistan

ns ~ ImportationsAfrica: Djibouti, SomaliaAsia : Bhutan, Japan


533

534


In 1975, the eradication of smallpox fromAsia was achieved and, with it, the end oftransmission of variola major virus, whichcaused the most severe form of smallpox . Bythe end of the year, endemic smallpox persist-ed only in Ethiopia, which had 66 knownoutbreaks, all of which were of variola minor,the mild form of smallpox .

Asia

In India and Nepal, the incidence ofsmallpox and the number of outbreaks de-creased steadily. Nepal detected its last case inApril and India in May . Bangladesh, however,was the site of yet another catastrophe assmallpox spread rapidly among the hundredsof thousands of persons displaced by floodsand famine and from them to settled popula-tions. Despite heroic efforts, the number ofoutbreaks increased from 78 in October 1974to 1280 in mid-May 1975. India strengthenedactivities in border areas and quickly con-tained the 32 importations that occurred .Emergency funds made available by Swedenand several other countries permitted therecruitment of additional international stafffor Bangladesh, and national mobilization bythe Bangladeshi authorities resulted in 12 000persons being fully engaged in eradicationwork. From May to August, the incidence inBangladesh diminished rapidly but work hadto be partially suspended in August, when thePresident of the country was assassinated .Officials feared civil war and yet another massexodus of refugees. Fortunately, the countryremained calm, smallpox eradication activi-ties could be resumed, and on 16 October1975 the last case occurred .

Africa

In Ethiopia, it had been expected that theeradication of smallpox would follow thesame pattern as in other African countries,with transmission being interrupted 2-3years after' the programme began . By 1975,however, the Ethiopian programme had been


in operation for 4 years and although the staffwere few in number, they were capable andstrongly motivated . Surveillance-contain-ment activities had been conducted since thestart of the programme and more than 10million persons had been vaccinated-nearlyhalf of Ethiopia's estimated population . Al-though the population density was low andthe habitations widely scattered, the mildvariola minor continued to spread . The prin-cipal problem area was the rugged highlandplateau, where resistance to vaccination wasgreat and where large areas were periodicallyinaccessible owing to civil war. As a result ofthe eradication of smallpox from Asia,additional resources could be provided, per-mitting a 5-fold increase in staff, but thehostilities within the country hampered theirefforts .

Other developments

Rumours of cases of suspected smallpoxbegan to be received with considerable fre-quency from countries considered to be free ofthe disease. Even though they proved false,arrangements had to be made to investigateeach rumour thoroughly and to publicize thefindings in order to maintain confidence ineradication. Another emerging problem wasthat of designing and implementing an ap-propriate strategy to permit eradication to becertified in the African countries, some ofwhich had detected no smallpox for manyyears and had consequently stopped theirsmallpox eradication activities . Certificationof eradication in Africa had been deferreduntil the continent as a whole had becomesmallpox-free. In 1975, however, it was decid-ed that because of the continent's vast size, thelarge number of countries, and the diminish-ing level of smallpox eradication activities,preparations for certification should com-mence as soon as possible . In February, thefirst of a number of planning meetings washeld, this one being concerned with methodsfor certification in western and central Africa .This implied that eradication in Africa wouldbe achieved, if not within the year, at leastsoon thereafter. At the end of 1975, however,that was by no means certain .

Q

J

Asia: Bangladesh, India, Nepal

ImportationsAfrica: Somalia

55 000

10 000

1 000

100

10


World

Plate 10.50 . Smallpox in the world, 1975 : eradication from continental Asia .

5 35

536


The Achievement of Global Eradication,1976-1977

As 1976 began, smallpox was known toexist in only 66 villages in Ethiopia but theinterruption of transmission there and inSomalia, where it became re-established laterthat year, proved to be as difficult as it hadbeen in mainland Asian countries in 1974-1975. Not until October 1977 was smallpoxfinally eradicated . A broad range of problemshampered the effort, from difficulties oftopography and transport, civil war andeventually war between Ethiopia and Soma-lia, socio-cultural problems posed by nomads,variolators and large groups who resistedvaccination, to the suppression of reports ofcases by the authorities in Somalia .

Ethiopia

Through mid-1976, the resources in Ethio-pia were concentrated in the central andnorthern highland plateau areas in whichcivil war was raging and most outbreaks wereoccurring . At great personal risk to the staffconcerned, these were gradually contained .Smaller numbers of staff worked in thesparsely settled south-eastern desert, wherethe few outbreaks occurred primarily amongnomads. From past experience in similar areasof western Africa, it had been assumed,erroneously, that smallpox transmission couldnot long persist in such a scattered, mobilepopulation. In the Ethiopian Ogaden desert,however, variola minor proved to be remark-ably tenacious, and operations were frequentlyinterrupted by warfare, the kidnapping ofteams and the destruction of vehicles andhelicopters. In August 1976, however, the lastknown outbreak in Ethiopia was containedand, for 7 weeks, no cases were reported fromanywhere in the world.

Somalia

From 1972 until February 1976, Somaliahad regularly reported importations fromEthiopia, but each was said to have beenpromptly detected . Late in September 1976,Somalia again reported several importedcases, this time in Mogadishu, the capital . Itwas learnt later, however, that these were buta few of many cases which were known to theauthorities. WHO staff and consultants werequickly sent to help but they were notpermitted to visit patients' houses or to traveloutside the capital. Repeated mass vaccina-tion campaigns throughout the city failed to

stop the spread of smallpox and fully 6months elapsed before an effective nationalprogramme could be established. By then, thedisease had spread widely throughout south-ern Somalia . A large-scale emergency effortwas mounted that started in March 1977 andinvolved adjacent areas of Djibouti, Ethiopiaand Kenya. More than 3000 cases weredocumented before the last case occurred on26 October 1977 .

Other developmentsDuring 1976-1977, certification activities

were organized in Asian and African coun-tries, often requiring special studies lasting ayear or more before a WHO internationalcommission could be invited to assess theprogramme and to certify eradication . InApril 1976 eradication was certified in 14countries of western and central Africa, and inDecember in Afghanistan and Pakistan ;in April 1977 in Bhutan, India and Nepal, inJune in 9 countries of central Africa, and inDecember in Bangladesh and Burma .

It became apparent in 1977 that an inde-pendent body would be needed to advise onthe measures that should be taken to givehealth authorities throughout the worldsufficient confidence in global eradication tobe willing to cease vaccination. A group ofinternational experts, which was convenedby WHO in October 1977, recommended anumber of measures, including the designa-tion by the Director-General of a GlobalCommission for the Certification of SmallpoxEradication. The Commission was to providecontinuing guidance and oversight to thecertification process and to report to theDirector-General when it was satisfied thatglobal eradication had been achieved .

The question of what should be done aboutthe stocks of variola virus retained in labora-tories around the world had long been atroublesome one. The destruction of most, ifnot all, such stocks was desirable but thisrequired the full cooperation of nationalgovernments and of the laboratories con-cerned . As a first step, a register of thelaboratories that held variola virus was pre-pared. Then, in 1977, the World HealthAssembly requested that all variola virusstocks should be destroyed, excepting thoseheld by WHO collaborating centres withmaximum containment facilities. Many labo-ratories soon complied and events in 1978served to speed the process.

Transmission interruptedEthiopia in August 1976

ImportationsKenya in 1976

o -Smallpox re-established

Somalia in 1976 (trarsmission interruptedOctober 1977)

x0a

E

w00na

55 000

10 000

100

10

J F MI

A M


Somaliax

'

I

I

I

I

I

I

I

I

I

I

I

I

I

J

J A S O N D J F M A M J

J A S O N D

1976

1977

11Somalia

Plate 10.51 . Smallpox in the world, 1976-1977 : global eradication .

537

538


The Certification and Formal Declarationof Global Eradication, 1978-1980

The period between the containment of thelast known outbreak and agreement by theThirty-third World Health Assembly (1980)that global eradication had been achieved wasas important but as difficult as had been thepreceding years. The world community had tobe confident of the attainment of eradicationand had to know of the measures which hadbeen taken to certify this. Laboratories had tobe persuaded of the need to destroy theirstocks of variola virus or to transfer them toWHO collaborating centres. Rumours ofpossible cases of smallpox had to be investi-gated and the findings publicized . Researchwas required to determine the nature of theviruses resembling variola virus which ap-peared to have been recovered from animals .An assessment of the risk of monkeypox tothose living in the tropical rain forests wasrequired as well as a determination of whetherthat virus could persist by human-to-humanspread. Provision also had to be made for thelong-term storage of vaccine reserves and forthe preservation of records .

However important and substantial theactivities which remained, the disappearanceof smallpox quickly resulted in a diminishedinterest in the programme . Only with diffi-culty were national governments persuadedof the need to assign resources for certifica-tion activities, and WHO's budget for small-pox decreased sharply. Remarkably, however,a rigorously scheduled array of activities wascompleted almost as planned .

During 1978, certification activities werecompleted in 19 countries, including most ofthose in southern Africa and western Asia .This brought to 64 the total of countrieswhere eradication had been certified by inter-national commissions. In December, the Glo-bal Commission decided that special activitieswere needed in 15 additional countries. It alsorecommended that an official attestation besought from all other countries to the effectthat the country concerned had been free ofsmallpox for at least 2 years. Difficult diplo-matic relationships, national sensitivities,civil disturbances and inertia caused seriousproblems in implementing the recommen-dations, but one by one the problems wereovercome. On 9 December 1979, the GlobalCommission concluded that the global eradi-cation of smallpox had been achieved and

approved a report that was presented to theThirty-third World Health Assembly in May1980.

The urgency for laboratories to destroy ortransfer their stocks of variola virus becameapparent when, in August 1978, 2 cases ofsmallpox with 1 death occurred as a result of alaboratory infection in Birmingham, Eng-land. National authorities took a greaterinterest in ensuring the safety of their ownpopulations and the number of laboratoriesretaining stocks of variola virus decreased to 6by May 1980, and eventually to 2.

In 1978, WHO announced a reward ofUS$1000 for the report of any new case whichcould be confirmed as smallpox, and some 50rumours a year were evaluated in 1978 and1979 by field investigation and laboratorystudy. Most proved to be chickenpox ; nonewas a case of smallpox .

Collaborative research on monkeypox andthe "whitepox" viruses, conducted in labora-tories in Japan, the United Kingdom, theUSA and the USSR, revealed the troublesome"whitepox" viruses to have been laboratorycontaminants. Field and laboratory studies ofmonkeypox virus provided increasing evi-dence that human infections were infrequentand that human-to-human transmissionseldom occurred .

Reserves of smallpox vaccine were estab-lished and a protocol was developed for theperiodic testing of samples to ensure theircontinuing potency.

Throughout this period, a special publicinformation effort was undertaken to makewidely known what had been accomplishedand how, so that when the World HealthAssembly agreed that eradication had beenachieved, the general public would accept thefact more readily .

The declaration on 8 May 1980 by theThirty-third World Health Assembly thatsmallpox eradication had been achievedconcluded an historic chapter in medicine .Twenty-two years had elapsed since the USSRhad first proposed to the Health Assemblythat global smallpox eradication should beundertaken, and 14 years since the Assemblyhad committed special funds to a programmewhich it hoped would interrupt transmissionwithin 10 years. In fact, 10 years, 9 monthsand 26 days elapsed from the beginning of theIntensified Smallpox Eradication Programmeuntil the last case in Somalia .

a chronology of progress,

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