Slide 1

Brucellosis Dr.shakeri 1

Slide 2

Brucella spp. Gram negative, coccobacilli bacteria Facultative, intracellular,Fastidious & aerobic organism Multiple species 2

Slide 3

3 Resistance of brucella Heating at 60CFor 10 minutes Phenol 1%For 15 minutes Direct sunlightIn a few hours MilkFor several days Fresh cheeseFor 3 months Tap-waterFor 57 days Human urineFor 1 week DustFor 6 weeks Damp soilFor 10 weeks Animal fecesFor 100 days

Slide 4

SpeciesBiovar/Ser ovar Natural HostHuman Pathogen B. abortus1-6, 9cattleyes B.melitensis1-3goats, sheepyes B. suis1, 3swineyes 2haresyes 4reindeer, caribouyes 5rodentsyes B. canisnonedogs, other canids yes B. ovisnonesheepno B. neotomaenoneDesert wood ratno B. maris (?)marine mammals?

Slide 5

5 Occurrence in Wildlife

Slide 6

6 SpeciesBiotypes Br. Abortus1,2,3,4,5,6,8,9 Br. Melitensis12 Br. Suis12 Br. CanisNot found Isolated species in Iran

Slide 7

The Many Names of Brucellosis Human Disease Malta Fever Undulant Fever Mediterranean Fever Rock Fever of Gibraltar Gastric Fever Animal Disease Bangs Disease Enzootic Abortion Epizootic Abortion Slinking of Calves Ram Epididymitis Contagious Abortion 7

Slide 8

Transmission to Humans Conjunctiva or broken skin contacting infected tissues Blood, urine, vaginal discharges, aborted fetuses, placentas, Sexual,Blood transfusion,Organ transplant Ingestion Raw milk & unpasteurized dairy products Rarely through undercooked meat 8

Slide 9

Transmission to Humans Inoculation with vaccines B. abortus strain 19, RB-51 B. melitensis Rev-1 Conjunctival splashes, injection Incubation varies 5-21 days to three months 9

Slide 10

10 Skin abrasion, conjunctivae, inhalation or ingestion Engulfed by neutrophils and monocytes (resistant to killing) Localize regional lymph nodes Infect phagocytic cells in the RE system and form granulomas Pathogenesis

Slide 11

11 Occurs worldwide Endemic areas - Africa, Asia True incidence not known

Slide 12

Who is at Risk? Occupational Disease Cattle ranchers/dairy farmers Veterinarians Abattoir workers Meat inspectors Lab workers Hunters Travelers Consumers of unpasteurized dairy products 12

Slide 13

13 Effect of Gender Men aged 15-45 years are affected twice as often as women of the same age Male predominance seem to be a factor in some cases The man is more likely than the woman to be exposed to the heaviest concentration of organisms

Slide 14

14 Effect of Gender In Iran both sexes are nearly always equally contacted with contaminated animals and dairy products There is not a significant predominance of male to female brucellosis in Iran

Slide 15

Sex distribution in Iran 15 Male 56% Female 44%

Slide 16

16 Age distribution Children are affected very much less than adults The odd low incidence in children is unexplained It may be that gastric acidity is less often deficient than in adult Occupational exposure is much more important

Slide 17

17

Slide 18

18 Mode of transmission 1 ) . 2 ) . 3 ) . 4 ) ( ) 5 ) . 6 ) ( ) . 7 ) . 8 ) . 9 ) (Congenital) .

Slide 19

B. abortus Worldwide Some countries have eradicated it Notifiable disease in many countries abortions, arthritic joints. Fever of Unknown Origin (FUO) ( ( Contagious/ Infectious abortion)

Slide 20

B. canis Poorly understood 1-19% prevalence in United States contact with aborted fetuses and semen. Rarely causes disease in humans. 20

Slide 21

B. suis Biovars 1 and 3 Worldwide problem. Free United Kingdom, Canada Eradicated Holland, Denmark Low Incidence Middle East, North Africa 21

Slide 22

Human Disease Can affect any organ or system All patients have a cyclical fever Headache, weakness, arthralgia, depression, weight loss, fatigue, liver dysfunction 22

Slide 23

Clinical manifestation Triad: Fever, Arthralgia / Arthritis, Hepatosplenomegaly +ve History of animal or food exposure 23

Slide 24

Skeletal 20-60% : arthritis, spondylitis, osteomyelitis. sacroiliitis - most common. athritis - oligoarticular : hip, knee & ankles. Joint asp. - monocytosis, culture +ve in 50 % 24

Slide 25

GIT 70% : anorexia, abd. pain, vomiting, diarrhea,contipation, hepatosplenomegaly. LIVER : Involved in most cases but LFTs normal or mildly abnormal. granulomas (B. abortus). hepatitis (B.melitensis). abscesses (B.suis). 25

Slide 26

Neurologic : Meningitis, encephalitis, radiculopathy & peripheral neuropathy, intracerebral abscesses Meningitis acute or chronic neck rigidity < 50% CSF lymphocytic pleocytosis (N) or low sugar increase protein culture +ve < 50% agglutination +ve in >95% 26

Slide 27

Genitourinary Epidydemoorchitis Pyonephrosis (rare) Cutaneous Nonspecific Hematologic Anemia Leukopenia Thrombocytopenia 27

Slide 28

Congenitally infected infants Low birth weight Failure to thrive Jaundice Hepatomegaly Splenomegaly Respiratory difficulty General signs of sepsis (fever, vomiting) Asymptomatic 28

Slide 29

29

Slide 30

30

Slide 31

31 Differential diagnosis Enteric fever Miliary TB Infectious mononucleosis Toxoplasmosis Acute rheumatic fever Malaria and relapsing f. Leishmaniasis Car-Scratch disease Typhoid fever TB Fungal infections

Slide 32

Diagnosis History of animal contact is pivotal In endemic area, it should be in the DDx of any nonspecific febrile illness 32

Slide 33

33 Laboratory changes Serologic Tests Tube Agglutination 2ME Agglutination Coombs test Complement fixation Radioimmunoassay ELISA Rapid Agglutination Rose bengal test

Slide 34

Laboratory changes Serologic Tests STA 2ME COOMBS C.F. RIS ELISA IgM + IgG IgG 1) If STA is negative and disease is chronic then only IgG 2) If STA is positive, IgM + IgG IgG IgG & IgM separately 34 Tests Antibodies which can be detected

Slide 35

Diagnosis in Humans Isolation of organism Blood, bone marrow, other tissues Serum agglutination test Four-fold or greater rise in titer Samples 2 weeks apart Immunofluorescence Organism in clinical specimens PCR 35

Slide 36

Laboratory WBC (N) or. Monocytosis ESR of little help Blood cultures slow growth = 4 weeks new automated system BATEC identifies he organism 4-8 days more recent (BACT/ALERT) - 2.8 days 36

Slide 37

37 Laboratory changes C.B.C Granulopenia in acute brucellosis Lymphocytosis in chronic brucellosis Atypical lymphocytosis Anemia due to hypersplenism Thrombocytopenia causing hemorrhage Moderate elevation of ESR

Slide 38

38 Laboratory changes Bacteriologic tests Taking bone marrow is more rewarding Brucella can be isolated from liver taken by biopsy Human semen may be positive

Slide 39

39

Slide 40

40 Serologic Tests IgM in acute brucellosis Rises first Is the only antibody for the first weeks Peaks at about 3 months Drop off after 3 months

Slide 41

Untreated Brucellosis 41

Slide 42

Treated Brucellosis Treatment 42

Slide 43

43 Laboratory changes Serologic Tests Serologic tests are based on rising and falling of IgM and IgG During re-infection or exacerbation, antibody titers become elevated In relapses, IgG may be the only antibody which rises

Slide 44

44 Standard tube agglutination test Is the most frequently utilized test Measuring antibodies to brucella abortus antigen A fourfold or greater rise in titer to 1:160 or higher is significant

Slide 45

45 Standard tube agglutination test Titer of => 1:160 is suggestive if there is symptoms consistent with brucellosis Acute brucellosis is most likely to be associated with a titer above 1:160 A great majority of patients will have titers of 1:160 to 1:320

Slide 46

46 Standard tube agglutination test Individuals with subclinical infection may demonstrate significant STA titers A diagnosis of brucellosis can not be established on the titers alone STA test can not differentiate persisting active infection from treated brucellosis

Slide 47

47 Standard tube agglutination test In chronic localized brucellosis STA titers may appear absent or low It is not useful in differentiating relapsing infection from other febrile illnesses in patients with past brucella infections

Slide 48

48 Standard tube agglutination test False positive results : F. tularensis Y. enterocolitica V. cholera Salmonella Vaccine against F. Y. V & S. Brucella skin testing Stenotrophomonas maltophila E. coli O157

Slide 49

49 Standard tube agglutination test False negative results Agammaglobulinemia First week of disease Disease due to Br. Canis Chronic brucellosis Prozone phenomenon

Slide 50

False-negative results in STA test Prozone & postzone phenomenon ( ) ( ) 50

Slide 51

51 False-negative results in STA test Prozone phenomenon The Prozone phenomenon appears to be related to the presence of IgG or IgA (Blocking antibodies) It can be eliminated if dilutions are carried out to at least 1:1280

Slide 52

52 False-negative results in STA test Brucella Canis infection The antigen used in the STA test does not reacts with brucella Canis If Br. Canis infection is suspected serologic tests specific for Br. Canis must be requested

Slide 53

53 False-negative results in STA test Chronic brucellosis STA test may be positive in low titer or may be negative Coombs test and C.F. tests may be positive A positive coombs test and CF test at 1:16 in such cases is strung evidence of continuing infection

Slide 54

54 Serologic Tests 2-Mercaptoethanol test (2ME) The STA test measures both IgM and IgG The addition of 2ME to the STA test results in the destruction of disulfide bonds of IgM 2ME test result is the detection of only IgG

Slide 55

55 Serologic Tests 2-Mercaptoethanol test (2ME) With prompt and adequate therapy IgG usually become undetectable within 5-12 months Those patients who develop persistent infection usually maintain elevated IgG agglutinins

Slide 56

56 Serologic Tests 2-Mercaptoethanol test (2ME) 2ME test will be negative if STA test is really negative 2ME test is less sensitive than STA test The prognosis of acute brucellosis may be predicted from the fall of 2ME

Slide 57

57 Serologic Tests 1:160 1:160

Slide 58

58 Serologic Tests A and M antigens Antigen A and M are common to the three main brucella species In the Br. Abortus, there is more A antigen than M antigen In the Br. Melitensis there is more M antigen than A antigen A M M A BABM

Slide 59

59 Serologic Tests A and M antigens Specific antigen may show higher agglutinin titers in patients infected with brucella other than Br. Abortus Ideally in all countries prepared antigen for serological testing should consist of predominant species A M M A BA BM

Slide 60

60 Serologic Tests A and M antigens In IRAN We have human brucellosis nearly always due to Br. Melitensis but use Br. Abortus antigen Br. Abortus antigen in our laboratories shows lower agglutinin titers A M M ABA BM

Slide 61

61 Serologic Tests A and M antigens In IRAN We must accept titers lower than 1:160 if there is signs and symptoms compatible with brucellosis A M M ABA BM

Slide 62

Comparison of serological tests using Br. Abortus and Br. Melitensis antigen Tests Due to Br. AbortusDue to Br. Melitensis A antigenM antigenA antigenM antigen STA Coombs 1:640 1:1280 1:320 1:640 1:5120 1:1280 1:10240 62 Ideally in all countries prepared antigen for serological testing should consist of predominant species

Slide 63

63 Serologic Tests Coombs test Serologic Tests Coombs test Serum may contain brucella antibodies which do not produce agglutination Non agglutinating antibodies are called incomplete antibodies Incomplete antibodies can be detected by addition of rabbit anti- human globulin

Slide 64

64 Serologic Tests Coombs test If STA is negative and there are symptoms and signs compatible with chronic brucellosis, then coombs titer of => 1:40 should be considered positive Coombs test is not recommended when STA test is positive

Slide 65

65 Serologic Tests Complement fixation test The CF test measures IgG antibodies Titers of => 1:16 should be considered positive

Slide 66

66 Serologic Tests Radioimmunoassay test RIA test determines anti-brucella IgM and IgG Avoids the difficulties with blocking or non-agglutinating antibodies Can differentiate between chronic and acute brucellosis

Slide 67

67 Serologic Tests ELISA test ELISA test can distinguish acute cases from chronic cases In ELISA test cross reaction can occur with yersiniosis

Slide 68

68 Serologic Tests Rose Bengal plate test Is an agglutination test in which the brucella cells are bound to a dye Is quick and easy to read It is a useful screening test

Slide 69

69 Brucella skin test (Brucellin) Demonstrate delayed hypersensitivity The antigen is a filtrate of a culture of brucella organisms or purified extract Injects intradermally

Slide 70

70 Brucella skin test (Brucellin) The test is positive if local redness with induration is present after 24-48 hours Antigen can provoke an antibody response or a significant rise in a pre-existing response Brucellin test, should not be performed

Slide 71

71 Laboratory changes PCR Tests The sensitivity was 100% The specificity of the test was 98.3%

Slide 72

Prognosis Preantibiotic era Mortality 2% mainly endocarditis Morbidity High with B. melitensis Nerve deafness Spinal cord damage 72

Slide 73

Prognosis May last days, months, or years Recovery is common Disability is often pronounced About 5% of treated cases relapse Failure to complete the treatment regimen Sequestered infection requiring surgical drainage Case-fatality rate: