Schistosomiasis mansoni in Burundi: progress in its control since 1985

Described is the evolution of the schistosomiasis control programme in Burundi since 1985. A single round of selective population chemotherapy was carried out in the Rusizi Plain and the Bugesera focus from 1985 to 1990. The prevalences and intensities of infection as well as the number of symptomatic cases detected in general health services decreased considerably. Annual sample surveys in the treated areas showed, however, that these improvements were rapidly reversed by reinfection of the demographically changing population. Since repeated selective population chemotherapy was not sustainable in the long term, a primary health care approach was adopted. In areas with good access to basic health services, approximately 10% of all schistosomiasis cases now receive treatment annually through this approach. Yearly selective chemotherapy in primary schools in suburban Bujumbura reduced the prevalence of schistosomal infection among pupils from 23% to 9% over the period 1984-90, and this programme has now been extended to highly endemic areas in Imbo-Sud. Focal snail control produced disappointing results, and emphasis has therefore shifted towards health education and environmental control of transmission.

Prevalence of depigmentation of the shins: a simple and cheap way to screen for severe endemic onchocerciasis in Africa

The prevalence of skin depigmentation in the pretibial region is closely correlated in the adult Congolese population with conventional indices (microfilarial index, mean microfilarial density, cyst index) for the evaluation of endemic onchocerciasis. Individuals over 15 years of age in endemic villages who had a microfilarial index of 80-90%, had a cystic index of 60-70% and a pretibial depigmentation index about 20% (30-40% for individuals aged > 50 years). Thus, in Africa, this new evaluation index offers a simple, noninvasive, quick and cheap way to identify areas where the level of endemic onchocerciasis is probably high and which are likely to benefit from an anti-onchocerciasis campaign.

Pleural effusion, tuberculosis and HIV-1 infection in Kigali, Rwanda

OBJECTIVE AND METHODS

An increasing number of diagnoses of pleural effusions (PE) have been made over the last 8 years in the Department of Internal Medicine of the Centre Hospitalier de Kigali, Rwanda. In order to determine the aetiology of PE and to examine its possible association with HIV-1 infection, we performed an aetiological work-up, including thoracocentesis and pleural punch biopsy, of all new patients with PE of undetermined aetiology referred to the Division of Pulmonary Diseases of the Department of Internal Medicine of the Centre Hospitalier de Kigali between 14 September 1988 and 16 October 1989. HIV-1 serological testing was performed for most of the patients.

RESULTS

A total of 127 patients (81 men, 46 women; mean age, 34 years; range, 16-71 years) with PE of undetermined aetiology were enrolled. Pleural tuberculosis was diagnosed in 110 (86%) and confirmed histologically and/or bacteriologically in 90 (82%). Of 98 pleural tuberculosis patients tested for HIV-1-antibody, 82 (83%) were HIV-1-seropositive. Metastatic cancer was responsible for PE in six (5%) patients, Kaposi's sarcoma in three, lymphoma in one (all four HIV-1-seropositive), anaplastic carcinoma in one, and adenocarcinoma in one (both HIV-1-seronegative). Non-tuberculous pneumonia was documented in five (4%) patients and was associated with HIV-1 infection in four. Other causes of PE were congestive heart failure (three patients), decompensated cirrhosis (one), constrictive percarditis (one), or undetermined (one); only one of these patients was HIV-1-seropositive.

CONCLUSIONS

We conclude that tuberculosis is the predominant cause of PE in our patients and is strongly associated with HIV-1 infection. Although less frequent, non-tuberculous pneumonia, Kaposi's sarcoma and lymphoma are other causes of HIV-1-associated PE. In an African area highly endemic for HIV-1 and Mycobacterium tuberculosis co-infection, PE should be considered a good marker of tuberculosis as well as HIV-1 infection.

Nuptiality patterns in two west African states

Using data from the Demographic Health Survey for Ghana and Senegal, the influences of education and rural versus urban residence, and the difference between the two states on proportions married by various ages and on singulate mean age at marriage are investigated.

Crossovers that link populations with the same vital rates

"In this paper, we consider crossovers of demographic density distributions from...populations that have the same fertility and mortality rates. We focus on observed populations and their associated stationary and stable models, and on proportional distributions of persons, births, deaths and reproductive values.... Three different populations were selected to represent a range of demographic behavior. Those populations are Japan 1963, a low mortality, low fertility population; Togo 1961, a high mortality, high fertility population; and the United States 1919-1921, a population whose fertility and mortality are intermediate."

Prevalence of enteric viruses among hospital patients with AIDS in Kinshasa, Zaire

Diarrhoea is the most common manifestation of acquired immunodeficiency syndrome (AIDS) in Africa. Numerous parasitic or bacterial agents have been implicated, but a pathogen-specific aetiology has not been found. Enteric viruses (i.e., rotavirus, small round structured viruses, coronavirus, and adenovirus) were detected by enzyme-linked immunosorbent assay or electron microscopy in faecal specimens of 17% of 198 consecutive adult admissions to a general medical ward of an urban hospital in Kinshasa, Zaire. Overall, 57% of patients were seropositive for infection with human immunodeficiency virus (HIV) 1; of these, 50% were classified as World Health Organization AIDS stage IV. The prevalence of enteric viruses in stool specimens did not differ significantly between patients with and without HIV infection, and was not associated with acute or chronic diarrhoea, or constitutional symptoms. However, a trend (P = 0.14) towards greater frequency of virus in stools from patients in the lower 3 quintiles of the CD4/CD8 T cell ratio was seen. This trend approached statistical significance (P = 0.07) with stratification by HIV infection. Although we found no evidence in this population to support a major pathogenic role for these viruses alone in the enteropathy of AIDS, increased viral shedding was weakly associated with immunodeficiency.

Salmonella bacteraemia among young children at a rural hospital in western Zaire

An analysis of 206 cases of extra-intestinal Salmonella infection among children up to 60 months of age admitted to a rural hospital in western Zaire was undertaken. Most children presented with fever but without any focus of infection which was difficult to distinguish clinically from falciparum malaria. The majority (83%) of the infections were due to serotypes other than S. typhi. Infection with these serotypes was clinically indistinguishable from S. Typhi infection and was associated with a comparably high case fatality rate of 23%. Death was significantly associated with age under 6 months (relative risk 1.7), meningitis (RR 4.7), jaundice (RR 2.5), severe anaemia (RR 1.8), contracting disease in the late wet season when malnutrition peaks (RR 2.6) and infection with a chloramphenicol-resistant isolate (RR 3.2). The increasing prevalence of antibiotic resistance and HIV infection will complicate the management of this disease in the future.

Estimating the incubation period of paediatric AIDS in Rwanda

OBJECTIVE

To estimate the distribution of the incubation period of paediatric AIDS in Rwanda.

DESIGN

Data were collected between February 1984 and December 1990 at the Centre Hospitalier de Kigali (CHK), the capital city of Rwanda, Central Africa.

PATIENTS

We used a sample of 685 AIDS cases registered consecutively in the Department of Paediatrics of the CHK, in which the proportion of perinatally acquired HIV-1 infection was estimated to be 98.6%.

METHODS

We performed both non-parametric and parametric analyses. The methods of estimation were adapted to truncated data, using essentially the same methods as Auger et al. in their analysis of data from the New York City and the New York State AIDS case registries in 1988.

RESULTS

We found that a double Weibull model fitted the data very well and that the risk of developing AIDS was high for subjects under 18 months of age, but lower for older subjects.

CONCLUSIONS

Our results were qualitatively similar to those of Auger et al.. There were quantitative differences between the two studies, but it was not possible to compare median survival periods. Parameters such as median or mean survival times cannot be validly estimated using only data from registers because these data exclude infected subjects who have not yet developed AIDS.

Diarrhea among African children born to human immunodeficiency virus 1-infected mothers: clinical, microbiologic and epidemiologic features

Diarrhea and weight loss are common features of pediatric and adult human immunodeficiency type 1 (HIV-1) infection, particularly in developing countries. We studied prospectively episodes of diarrhea in 559 children, ages 10 to 15 months, participating in a longitudinal study of perinatal HIV-1 infection in Kinshasa, Zaire. Children with HIV-1 infection had more frequent episodes of diarrhea and were more likely to present with fever or moderate or severe dehydration and to have persistent or fatal diarrhea. Of 9 HIV-1-positive infants with diarrhea, 3 had enteroadherence factor-positive Escherichia coli, compared with 5 of 74 HIV-1-negative children with diarrhea (P = 0.04); no other pathogen was associated with HIV-1 infection. In a logistic regression model diarrhea was significantly associated with HIV-1 infection in the child, moderate or severe malnutrition and symptoms of acquired immunodeficiency syndrome in the mother. Diarrhea among children with perinatal HIV infection in Zaire is more severe than among uninfected children and is associated with malnutrition and advanced disease in the mother.

Two-year incidence of tuberculosis in cohorts of HIV-infected and uninfected urban Rwandan women

To determine the prevalence of Mycobacterium tuberculosis infection and the incidence of tuberculosis in HIV-infected and uninfected urban Rwandan women, 460 HIV-positive and 998 HIV-negative childbearing women were recruited from pediatric and prenatal care clinics and were enrolled in a prospective study in 1988 and followed for 2 yr. Tuberculin testing was administered 12 to 18 months after enrollment. Fifty-three percent of HIV-negative women had positive tuberculin tests (induration > or = 10 mm), with higher rates among older women and among women who had received BCG vaccine. Only 21% of HIV-positive women had positive tuberculin tests, with no relationship to BCG vaccine. Follow-up was available for 93% of subjects. Tuberculosis was diagnosed in 20 HIV-positive women and in two HIV-negative women. Features associated with an increased risk of tuberculosis among HIV-positive women included: age > or = 30, body mass index in the lowest quartile, low income, erythrocyte sedimentation rate > 75, positive tuberculin test, and chronic cough, chronic fever, and weight loss. Among Rwandan women who are infected with HIV, approximately half of those who are infected with M. tuberculosis do not have positive tuberculin tests. The rate ratio for development of tuberculosis among HIV-positive women was 22 (95% CI, 5 to 92). New algorithms are needed to improve the early detection of tuberculosis among HIV-positive patients in Africa.