Rabies in apparently healthy dogs: histological and immunohistochemical studies.

A slaughterhouse survey for rabies virus infection among apparently healthy dogs slaughtered for human consumption was carried out in Maiduguri, Nigeria. Formalin-fixed and paraffin-embedded tissues (salivary gland, hippocampus, cerebrum, medulla, and trigeminal ganglion) were obtained from a total of 52 head samples from slaughtered dogs. The paraffin-embedded tissues were analysed histologically using the haematoxylin and eosin (H&E) method for the presence of inclusion bodies and histochemically by streptavidin - biotin peroxidase staining method for detection of rabies virus antigens. Prior to fixation of tissue, impression smears were made from the hippocampus and stained by Sellers method to detect the presence of Negri bodies. Rabies virus antigen was detected in tissues from 16 (31% ) of the 52 dog heads. Histological diagnosis by H&E revealed various degrees of inflammatory changes in the salivary gland and brain tissues with few Negri bodies from 10 (19% ) of the 52 dogs tested. However, all tissues positive by H&E were also positive by immunoperoxidase method using the streptavidin- biotin peroxidase staining procedure. Ten (30% ) of the 33 male and 6 (32% ) of the 19 female dogs tested were positive for presence of rabies virus antigen. There was no significant difference between sexes in relation to rabies virus infection. The application of immunoperoxidase staining technique in the localization of rabies virus antigen in the submaxillary salivary gland was more sensitive (based on the relative number of positive tissues) when compared with the application of the method to other organs. Apparently healthy dogs may be important in the epidemiology and control of rabies in this environment.

Prevalence of HIV-1 infection among patients with leprosy and pulmonary tuberculosis in a semi-arid region, Nigeria.

Much evidence exists on pulmonary tuberculosis (PTB) as a presenting feature of HIV infection or AIDS-related complex, while few reports exist of a direct association between HIV infection and leprosy. This study was carried out to see whether or not an association between leprosy and HIV infection existed, similar to that of PTB in the region of Maiduguri, Nigeria. Of 105 patients with leprosy, 11(10.5%) were positive for HIV antibody. Of 58 patients with suspected PTB, 11(19%) were positive for HIV antibody. Twenty-seven (47%) of the 58 had active PTB, with results of sputum smear and culture positive for mycobacterium, and six of these (22.2%) were also positive for HIV antibody. Odds ratios (OR) obtained by conditional logistic regression (matched) analysis were 3.52 (95%, CI 1.03-12.07) and 2.53 (95%, CI 1.04-6.15) for association between HIV-1 and PTB and leprosy, respectively. HIV infection was more prevalent among leprosy patients aged under 30 years, OR = 4.25 (95%, CI 1.25-14.42). The prevalence of HIV-1 infection was at borderline significance, higher in PTB and leprosy patients than in blood donors, Fisher's exact test (two-tailed) p = 0.07 and p = 0.05, respectively.

Prevalence of hepatitis B surface antigen among patients suspected of liver diseases in a Nigerian hospital.

Hepatitis B virus (HBV) infection has been reported to be the aetiological factor for hepatocellular carcinoma (HCC), hepatitis and liver cirrhosis. This study was therefore carried out to determine the seroprevalence of hepatitis B surface antigen (HBsAg), a specific marker of HBV infection in patients with suspected liver diseases. The investigation was carried out among patients attending the University of Maiduguri Teaching Hospital (UMTH), Nigeria with clinical symptoms suggestive of liver diseases and others with non-specific clinical features during the period from 1990-1995. A total of 197 (38%) of 517 patients tested positive for HBsAg, 81 (49%) out of 144 with symptoms suggestive of hepatitis, 75 (50%) of 149 HCC and 10 (56%) of 18 liver cirrhosis were HBsAg positive. Comparison of the yearly total prevalence values of HBsAg for the six years under study showed no significant difference. Similarly, yearly prevalence values amongst patients with suspected liver diseases showed no significant differences. Nevertheless, significant difference, (P < 0.05) between the prevalence of HBsAg among suspected cases of liver diseases and others with non-specific signs and symptoms was observed. Similarly, HBsAg was statistically significantly higher among males than females. The high prevalence rate of HBsAg in our environment may be associated with the suspected cases of liver diseases, which are equally prevalent in our locality. Health education to prohibit traditional practices that could predispose individuals to HBV infections is emphasised. The incorporation of HBV vaccination in the national programme on immunization currently in use in Nigeria is highly recommended. This would be an effective method of preventing HBV infection from childhood.

Presentation and outcome of HIV-1 infection in hospitalised infants and other children in north-eastern Nigeria.

There is limited information on HIV infection in children in West Africa. This prospective case series study was done to determine the size of the problem and the feasibility of selective screening for infection based on clinical presentation. It involved infants and other children admitted to the Children's Emergency Ward and Paediatric Medical Ward of the University of Maiduguri Teaching Hospital, Nigeria, from the beginning of September 1992 to the end of September 1994. Clinical evaluation followed by serologic tests (ELISA and Western blot techniques) was undertaken. Descriptive study; frequencies were compared using chi 2 test for Fisher's exact test as appropriate. One hundred and ninety nine (10.9%) of 1,822 admissions were screened. One hundred and fifty eight (79.4%) were ELISA negative and 17 (8.6%) ELISA and WB positive; a further 10 (5%) were ELISA positive but WB indeterminate and 14 (7%) were ELISA positive but WB negative in 12 or untested in two. All the infections were HIV-1. Sixteen (39%) patients (nine WB positive, three WB indeterminate and four ELISA positive only) are dead, 14 from HIV-related illnesses, two (4.9]) are alive and 23 (56.1%) lost to follow up; 11 of the HIV-related deaths involved infants. Presence of persistent diarrhoea, prolonged fever, oral thrush, hepatosplenomegaly, diagnosis of tuberculosis and severe malnutrition with gastroentereritis, and multiple (> 3) diagnosis on admission were significantly (p < 0.05) associated with WB confirmed HIV-1 seropositivity and could serve as indicators for selective screening. HIV-1 infection in hospitalised infants and children has become an important problem in Nigeria, presentation in infancy is associated with a high case fatality rate, and the practice of selective screening based on clinical presentation would appear to be feasible.