417

When the typhoid strain is chloramphenicol-resistant, ampicillin is likely to be the drug of choice.Such strains can be expected to show widespread drugresistance, including resistance to the sulphonamides.Modest to considerable success with co-trimoxazole

(trimethoprim/sulphamethoxazole) in the treatment oftyphoid fever has been claimed by many workers. 6-8If a chloramphenicol-resistant strain is not alsoresistant to sulphonamides, then co-trimoxazole wouldbe preferable to ampicillin.

ORAL ENTERIC BACTERIAL VACCINES

" AT the moment, none of the parenteral vaccinesagainst enteric bacterial infections is wholly satisfactory;these vaccines are lacking in efficacy; the duration ofthe immunity they confer is inadequate; they tend tocause side reactions; and the cost of using them toimmunize the population most at risk is excessive."These words appear in the introduction to a report ofa W.H.O. study-group,9 and are a powerful justificationfor reassessing oral vaccines against enteric fever,shigellosis, cholera, and Escherichia coli enteritis. Thegroup concludes that oral prophylaxis has manyadvantages and may become the most desirable methodof immunisation, but, despite major advances in recentyears, knowledge of the basic mechanisms involved ininducing immunity via the intestinal mucosa is still

fragmentary.

The report analyses in turn the pathogenesis of eachof the four major groups of intestinal infections. Italso examines the general immune defences of thealimentary tract, including non-specific resistancemechanisms such as are provided by gastric acidity,and discusses the roles played by antibody-mediatedand cell-mediated immunity in the context of intestinalinfections. The various oral prophylactic agents thathave been tested in man or laboratory animals arereviewed under the headings of killed whole vaccines,live vaccines, and vaccines based on extracts and frac-tions of organisms. One of the most promisinginvestigations, which now spans almost a decade, hasinvolved the Yugoslavian trial of live vaccines againstshigella species prepared from mutant strains selectedon the basis of streptomycin-dependence. These are

given in four or five doses at 2-4-day intervals withsodium bicarbonate, and have resulted in protection-rates of 85-100%. Reversion to virulence is one of thepossible hazards of this kind of approach, and revertantshave been recognised in laboratory work under in-vitroconditions; but control tests carried out on stool

specimens from vaccinated people have not indicatedthat reversion happens in vivo. Whilst this experiencemust be regarded as extremely encouraging, theobservations are, of course, preliminary.

6. Farid, Z., Hassan, A., Wahab, M. F. A., Sanborn, W. R., Kent,D. C., Yassa, A., Hathout, S. E. ibid. 1970, iii, 323.

7. Geddes, A. M., Fothergill, R., Goodall, J. A. D., Dorken, P. R.ibid. 1971, iii, 451.

8. Scragg, J. N., Rubidge, C. J. ibid. p. 738.9. W.H.O. tech. Rep. Ser. no. 500, 1972.

Many other approaches to the problem of oralvaccination are discussed in the report, ranging fromelaborate techniques involving preparation of genetichybrids between virulent Shigella flexneri and aviru-lent E. coli strains, to purified bovine preparationsof enzyme-resistant immunoglobulins for possible usein passive immunisation against E. coli enteritis ininfants. Questions of safety and of the criteria forassessing the efficacy of an orally administered vaccineare looked into in some detail. The report concludeswith a long list of recommendations for furtherresearch, including some for fundamental studies ofthe immune mechanisms operating through theintestinal mucosa and others for work on moreimmediate problems with vaccines now in existence orin prospect. The report, the 500th of the W.H.O.Technical Reports, maintains the high standardcustomary in this series.

HAIR AUTOGRAFTS

VANITY is not the prerogative of women; none the less,it has only been in recent years that fashion has decreedthat it is not effeminate for a man to preen himself

overtly. This trend has been accompanied by thedevelopment of new ways of disguising baldness.

Obviously, the most effective method of disguise wouldbe one that is permanent and which requires no after-care or maintenance. This is probably why hairtransplantation with hair autografts has been usedincreasingly in the United States during the pastdecade in the treatment of ordinary male alopecia.

Orentreich described the procedure in 1959 1 andhe has lately summarised its applications and his

experience with it. Essentially it involves transferringpunched-out cylinders of hair-bearing skin from theperiphery of the scalp (which is not usually involvedin male baldness) to a prepared site on the bald area.This manoeuvre is successful because of the dominanceof the donor tissue at its new site. Technically, thesize of the punches employed vary from 2 mm. to4 mm. in diameter. The transplants must be insertedin a direction parallel to that of the hair follicles at thedonor site. Care is also taken at the recipient site toinsert the cylinder of hair-bearing skin at the correctangle into a cavity prepared using the same sizedpunch. The whole procedure is performed under localanaesthesia, and 10-15 transplants are made at onesitting. The cosmetic results are said to be good, andthe incidence of complications is said to be extremelylow. Orentreich admits that infection occurs in 1%and keloids develop in 0-1%.

Apart from male baldness, hair transplantation hasan obvious application for the treatment of the scarringalopecias such as those due to trauma or lupuserythematosus. Clearly, this procedure is a useful oneto have available, although, fashion being as unpre-dictable as it is, the virile bald look may soon be inagain.

1. Orentreich, N. Ann. N.Y. Acad. Sci. 1959, 83, 463.2. Orentreich, N. N.Y. St. J. Med. 1972, 72, 578.