Contribution of Xpert® MTB/RIF to tuberculosis case finding among pregnant women in Botswana.

SETTING: Seven health facilities with antenatal care (ANC) clinics in two districts near Gaborone, Botswana. OBJECTIVES: To determine 1) the prevalence of tuberculosis (TB) and HIV-TB co-infection in pregnancy, and 2) the sensitivities of symptomatic TB screening and Xpert testing against gold standard culture. DESIGN: This was a cross-sectional study. Pregnant women were randomly enrolled and screened using TB symptoms. HIV status was determined from ANC clinics' client records. Two sputum specimens were collected from all clients and each was tested using Xpert® and culture for Mycobacterium tuberculosis. RESULTS: Of 407 cases, eight had one or more TB symptoms, and all tested negative with Xpert® and culture. Another two (0.5%, 95%CI 0.08-1.96) asymptomatic clients tested positive with both tests. The adjusted TB prevalence was higher than that of the general population (0.6% vs. 0.24%; P < 0.001). The prevalence of TB among HIV-positive and HIV-negative clients was 1/69 (1.45%, 95%CI 0.29-2.61) and 1/336 (0.3%, 95%CI 0.23-0.83), respectively (Fisher's exact test P = 0.312). Xpert® demonstrated a 100% sensitivity and 100% specificity, while symptom screening had 0.0% sensitivity and 98% specificity. CONCLUSIONS: TB prevalence among pregnant women was high and TB symptom screening had limited ability to detect TB. An alternative TB screening algorithm for pregnant women is urgently needed irrespective of TB symptoms.

OBJECTIFS: Déterminer 1) la prévalence de la tuberculose (TB) et de la co-infection VIH-TB pendant la grossesse, et 2) la sensibilité du dépistage de la TB basé sur les symptômes et de l'Xpert® MTB/RIF par rapport à l'étalon or de la culture. SCHÉMA: Ceci est une étude transversale. Des femmes enceintes venant de sept centres de santé ont été enrôlées de façon aléatoire et dépistées en fonction des symptômes de TB. Deux échantillons de crachats ont été recueillis chez toutes les femmes et chacune a eu un test Xpert® et une culture. Le statut VIH a été déterminé grâce aux dossiers de consultation prénatale. RÉSULTATS: Sur 407 femmes enrôlées et analysées, huit (2,0% IC95% 0,62­3,32) avaient un ou plusieurs symptômes de TB et toutes ont été négatives pour l'Xpert® et la culture. Deux autres femmes (0,5% ; IC95% 0,08­1,96) asymptomatiques ont été positives pour les deux tests. La prévalence ajustée de TB est plus élevée que dans la population générale (0,6% contre 0,24% ; P < 0,001). La prévalence de TB parmi les femmes positives au VIH et non infectées a été respectivement de 1/69 (1,45% ; IC95% 0,29­2,61) et 1/336 (0,3% ; IC95% 0,23­0,83) (test exact de Fisher, P = 0,312). L'Xpert® a démontré une sensibilité de 100% et une spécificité de 100,0% alors que le dépistage sur les symptômes a eu une sensibilité de 0,0% mais une spécificité de 98%. CONCLUSION: La prévalence de la TB chez les femmes enceintes est élevée et le dépistage sur les symptômes a une capacité limitée de détection de la TB. Il y a un besoin urgent d'un algorithme alternatif de dépistage de la TB pour les femmes enceintes quels que soient leurs symptômes de TB.

Relationship of childhood protein-energy malnutrition and parasite infections in an urban African setting.

A clear understanding of protein-energy malnutrition (PEM), parasite infection and their interactions is essential in formulating health and development policies. We studied the prevalence of PEM indicators and the prevalence and/or intensity of infection in 558 Zairian children aged 4 months to 10 years. Multivariate analyses were used to estimate relationships between PEM indicators and parasitic infection. Stunting was found in 40.3% of children, wasting in 4.9% and kwashiorkor in 5.1%. The risk of stunting was significantly higher in children with Ascaris lumbricoides. The risk of wasting was higher in children with A. lumbricoides or Trichuris trichiura, whereas the risk of kwashiorkor was high with T. trichiura but very reduced in those with A. lumbricoides. Plasmodium infection was not related to nutritional indicators. These relationships highlight important interactions, both synergistic and antagonistic, between nutrition and parasites in central Africa.

Multiple infection with Plasmodium and helminths in communities of low and relatively high socio-economic status.

A study was conducted in the city of Lubumbashi, Zaire: (1) to survey parasitic infections and clinical conditions in the local children and their mothers; (2) to identify combinations of parasites and clinical conditions that commonly occurred together in individuals; and (3) to determine whether single- and/or multiple-species infections were risk determinants of the observed clinical conditions. Overall, 1100 children and mothers from three subdivisions, two of low socio-economic status (LSES) and one of relatively high socio-economic status (HSES), provided stool and blood samples and were clinically examined. Plasmodium prevalence was higher in the two LSES subdivisions than in the HSES subdivision. Prevalence and intensity of Ascaris lumbricoides infection were low in the HSES subdivision and one of the two LSES subdivisions. In contrast, prevalence and intensity of Trichuris trichiura and of hookworms were similar in all subdivisions. Plasmodium and A. lumbricoides were the most frequently found single-species infections. The combination of A. lumbricoides and Plasmodium was the most frequent double-species infection and that of A. lumbricoides, Plasmodium and T. trichiura was the most frequent triple-species infection. Significant positive associations between parasite species were detected in the HSES subdivision, and in one of the two LSES subdivisions. Because the relationships were not consistently detected, it is hypothesized that the associations are determined by environmental conditions rather than synergy between the parasites in the host. The most commonly observed clinical conditions were abdominal pain, diarrhoea, fever, and low packed-cell volume (PCV). The occurrence of each was significantly lower in the HSES subdivision than in at least one of the two LSES subdivisions. Abdominal pain and low PCV were most common in individuals presenting with only a single clinical condition, and the combination of this symptom and sign was the most commonly observed pair of conditions. Abdominal pain, low PCV and diarrhoea was the most common combination in individuals with three clinical conditions. Logistic regression revealed that hookworm infection, T. trichiura infection, young age and residence in an LSES subdivision were determinants of diarrhoea. Trichuris trichiura infection, young age and living in an LSES subdivision were risk factors for abdominal pain. Plasmodium infection and young age were risk factors for fever. LSES was the only predictor of low PCV. Infection with A. lumbricoides did not enter any of the models. No significant interactions were detected among parasites, indicating that there was no synergism or antagonism among parasites in the induced disease.

Ascaris lumbricoides infection and environmental risk factors in an urban African setting.

Identification of appropriate strategies for controlling gastro-intestinal nematodes in communities depends, in part, on an understanding of the conditions that increase risk of exposure to infective stages. The present study was conducted in Lubumbashi, Zaire. The objectives were to identify features of the environment and living conditions that were significant predictors of Ascaris lumbricoides infection, and to determine whether the same predictors were important in populations living in subdivisions of lower (LSES) and higher (HSES) socio-economic status. Forty-two households from each of three subdivisions (two LSES and one HSES) were selected at random. Mothers were interviewed, observations on the environment around the home were recorded, and single stool samples, collected from all children and mothers, were examined for nematode eggs. Maternal education was a significant predictor of A. lumbricoides intensity in both LSES and HSES subdivisions. Factors related to poor sanitation (open defecation and high number of people using the same toilet) were important in the LSES subdivisions but not in the HSES subdivision. In contrast, the ratio of relatives to direct family members per household was a significant predictor of high intensity of infection in the HSES subdivision, but not in the LSES subdivisions, indicating that relatives and live-in visitors contribute to Ascaris transmission in the HSES population.

The microepidemiology of wasting syndrome, a common link to diarrheal disease, cancer, rabies, animal models of AIDS, and HIV-AIDS YHAIDS). The feline leukemia virus and rabies virus models.

Infant cats were inoculated intracranially with rabies or feline leukemia viruses in an experimental study of wasting syndrome. The daily pre- and postinoculation body weights were recorded until kittens were moribund. Affected animals in both groups manifested growth failure or wasting syndrome. Immunodepression, manifested by a conspicuous depletion of thymic cortex, the thymus dependent areas of the spleen, and growth hormone producing-alpha adenopituicytes was significantly (p less than 0.01) related to the wasting status of the animals. The ability of pituitary glands from these animals to produce growth hormone was studied by in situ immunoperoxidase staining and showed a significant (p less than 0.01) difference between healthy and wasted animals. Rabies and feline leukemia viruses were each found responsible for the low immunoreactivity of growth hormone producing alpha adenopituicytes. Because the hypothalamus and the hypophysis were both found infected, it was concluded that regardless of the triggering agent in primary wasting, the hypothalamic-hypophyseal-thymic axis was always involved through a decrease in growth hormone production.

Failure to thrive, wasting syndrome, and immunodeficiency in rabies: a hypophyseal/hypothalamic/thymic axis effect of rabies virus.

Studies of rabies virus in several animal models consistently showed hypothalamic infection, hypophyseal infection, dramatic growth impairment (in the form of failure to thrive), wasting syndrome, and immune depletion. Rabies virus infection was studied through routine monoclonal antinucleocapsid antibody immunofluorescence and through a peroxidase-antiperoxidase immunoperoxidase method. The latter was modified to detect the in situ production of growth hormone by uninfected and rabies virus-infected adeno-a-pituicytes (with confirmation of the results both in vivo and in vitro). Infection with rabies virus made the specialized pituicytes produce less growth hormone. Growth before rabies virus infection and its reduction due to infection were investigated in a linear regression model. The fit was statistically significant (P less than .05) in all species studied: mouse, rat, rabbit, cow, and cat. Immune depression was studied in terms of alterations in the immunotopography of the thymus and also the specific T- and B-cell homing areas of the spleen (although spleen data are not presented here). On the basis of these results and a thorough review of wasting syndromes encountered in other diseases, a primary failure to thrive and an ensuing wasting syndrome were described and characterized for rabies, and their origin was assigned to a dysfunction of the hypophyseal/hypothalamic/thymic axis associated with at least (but not necessarily only) one of the centrally controlled growth hormones.