Serological and cultural examination for human leptospirosis in Plateau State, Nigeria.

In a serological examination of 710 serum samples collected from human volunteers in Plateau State, Nigeria, 128 (18.0pc) had leptospiral antibody titres of 1:100 and above. The prevalence of antibodies to individual serovars were: hardjo 28 (21.9pc), pomona 18 (14.1pc), canicola 17 (13.3pc), grippotyphosa 15 (11.7pc), pyrogenes 13 (10.2pc), icterohaemorrhagiae 12 (0.4pc) and autumnalis 8 (6.3pc). There was no statistical difference in the prevalence rate of leptospirosis in the different local government areas (p greater than 0.05; X2). Among the occupational groups examined, the abattoir workers were particularly at risk with a prevalence rate of 29.5pc. A leptospiral variant of strain Hardjoprajitno was also isolated from the midstream urine of an abattoir worker who was apparently healthy. The isolation of Leptospira interrogans serovar hardjo in man is the first such report in Nigeria.

Isolation of Corynebacterium renale from slaughtered cattle at the Zaria abattoir in Nigeria.

Forty urinary bladders were collected from apparently healthy cattle slaughtered at the Zaria abattoir. Twenty-four (60%) were from male animals and 16 (40%) from females. Urine samples were obtained and cultured for Corynebacterium renale. Four (16.7%) of the samples from males and 1 (6.3%) from females were positive. The difference in infection between the sexes was statistically significant (P less than 0.001).

A new leptospiral serovar in the Pyrogenes serogroup isolated in Nigeria.

Five leptospiral strains were isolated from bovine kidneys during a cultural survey for pathogenic leptospires in Nigeria. Preliminary test results indicated that the five strains were identical and serologically heterologous to the other members of the Pyrogenes serogroup. Further examination of the strains by the cross-agglutinin absorption test, factor analysis and restriction endonuclease analysis confirmed that the strains constitute a new serovar. It is therefore proposed that this strain be recognised and designated as serovar nigeria, type strain Vom.

Serological prevalence of bovine leptospirosis in Plateau State, Nigeria.

Serum samples obtained from 1.537 cattle in the 14 local government areas (LGAs) of Plateau State of Nigeria were screened for the presence of leptospiral antibodies using 13 serovars in a modified microscopic agglutination test (MAT). Two hundred and twenty-two (14.4 p.100) of the cattle tested had leptospiral antibody titres of 1:100 or higher to one or more of the test antigens. The prevalence rates of antibodies to individual serovars were: hardjo (35.6 p.100), pomona (11.7 p.100), pyrogenes (11.7 p.100), canicola (9.5 p.100), grippotyphosa (7.7 p.100), bratislava (5.9 p.100), icterohaemorrhagiae (5.9 p.100), ballum (4.5 p.100), autumnalis (3.6 p.100), bataviae (2.3 p.100) and tarassovi (1.8 p.100). The serological prevalence of bovine leptospirosis in the various local government areas of Plateau State of Nigeria differed significantly (P less than 0.05; X2).

Vaccination challenge studies with variants of street rabies virus isolated in Nigeria.

In a preliminary study it was observed that adult ICR mice immunized with serial dilutions of an inactivated experimental human rabies vaccine from the Pitman-Moore (PM) vaccine virus were well protected against challenge with homologous virulent PM virus and challenge virus standard (CVS). However only one of five variant representatives in five of seven groups of 41 isolates of street rabies virus from Nigeria characterized by hybridoma monoclonal antibodies specific for the nucleocapsid and glycoprotein antigens of rabies virion was protected for by the vaccine. Guinea pigs immunized with a live attenuated low egg passage (LEP, Flury strain) vaccine currently used in canine vaccination in Nigeria protected against challenge with all five variants. The LEP vaccine protected against the variants and CVS quite well even when 1:125 dilution of the vaccine was used.

Atypical Pasteurella haemolytica type A from poultry.

Atypical strains of Pasteurella haemolytica that failed to ferment maltose were isolated from nodular necrosis in the liver and heart blood of domestic fowl (Gallus domestica). These strains did not typically behave like either of the two well-known biotypes of P. haemolytica. The strains utilized trehalose and produced hydrogen sulfide (H2S), thus behaving like P. haemolytica type T, and produced acid in xylose but not in salicin, thus behaving like P. haemolytica type A. Most of the properties of the strains, however, conformed closely to those of P. haemolytica type A. Detailed characteristics of the isolates are described and discussed.

Bacteriological investigation of the postpartum uterus: Relationship to involution and histopathological findings.

A bacteriological investigation of the postpartum uteri of suckled and nonsuckled Bunaji (White Fulani) cows was undertaken to determine the microflora, the effect of suckling on the flora and the influence of the flora on uterine involution and histopathology. Uterine contamination by bacteria was highest between days 10 and 21 postpartum with Staphylococcus aureus being the commonest organism isolated. There was no consistent isolation of one type of bacterial organism from a cow throughout the sampling period. Suckling did not affect the incidence of uterine contamination by bacteria. Foci of leucocytes (mainly lymphocytes) were found in uterine sections in an increasing frequency with days postpartum. Bacteria were isolated from only 3 of the 12 uteri that had the leucocytic foci. Uterine involution was normal and complete by 25 days after calving irrespective of the presence or absence of bacteria or leucocytic foci. We concluded that postpartum uterine contamination by bacteria was not influenced by suckling and that puerperal uterine contamination by bacteria did not interfere with the normal process and duration of uterine involution.

Investigation of the presence of Salmonella in two Nigerian meat packing plants.

Two large and very well established meat processing plants supervised by the Veterinary Public Health Department were examined to assess the incidence of Salmonella within the premises and on the processed carcasses. The overall incidence was 65 out of the 252 samples or 25.9%. Salmonella was found in forty-one of 167 samples (25%) in one and twenty-four out of eighty-five samples (29%) in the other. The high incidence shows a high degree of probability of contamination of the products from both plants. The public health significance of the findings is emphasized and control problems are high-lighted.

Pathologic changes in lizards (Agama agama) experimentally infected with Dermatophilus congolensis.

Captive laboratory-held lizards (Agama agama) experimentally inoculated with Dermatophilus congolensis by subcutaneous, intramuscular and intraperitoneal routes developed pyogranulomatous and necrotic lesions at and around the sites of inoculation. D. congolensis was consistently cultured from the lesions even at 75 days post inoculation. Histopathologic examination of selected organs and tissues showed granulomatous caseous abscesses in the dermis, subcutaneous tissue and liver, edema of the dermis and widespread muscular degeneration and necrosis. D. congolensis organisms were associated with these lesions. No lesions or organisms were seen in the epidermis of the skin.

Cure of Dermatophilus congolensis infection in cattle by long-acting oxytetracycline.

Under conditions simulating traditional husbandry, a single intramuscular dose (20 mg/kg) of long-acting oxytetracycline was efficacious in treating different grades of bovine dermatophilosis. There was complete healing in 26 out of 28 animals (93 per cent) within four weeks. By contrast, only four out of 11 animals treated with penicillin (70,000 iu/kg) plus streptomycin (70mg/kg) were apparently cured and three relapsed within one month. No spontaneous recoveries were observed among 18 untreated animals. In the group treated with oxytetracycline, two, in the penicillin plus streptomycin, seven, and in the untreated control group, 11 animals died of the disease.