Utility of CD4 count measurement in the era of universal antiretroviral therapy: an analysis of routine laboratory data in Botswana.

OBJECTIVES: National guidelines in Botswana recommend baseline CD4 count measurement and both CD4 and HIV viral load (VL) monitoring post-antiretroviral therapy (ART) initiation. We evaluated the utility of CD4 count measurement in Botswana in the era of universal ART. METHODS: CD4 and VL data were analysed for HIV-infected adults undergoing CD4 count measurement in 2015-2017 at the Botswana Harvard HIV-Reference Laboratory. We determined (1) the proportion of individuals with advanced HIV disease (CD4 count < 200 cells/µL) at initial CD4 assessment, (2) the proportion with an initial CD4 count ≥ 200 cells/µL experiencing a subsequent decline in CD4 count to < 200 cells/µL, and (3) the proportion of these immunologically failing individuals who had virological failure. Logistic regression modelling examined factors associated with advanced HIV disease. CD4 count trajectories were assessed using locally weighted scatterplot smoothing (LOWESS) regression. RESULTS: Twenty-five per cent (3571/14 423) of individuals with an initial CD4 assessment during the study period had advanced HIV disease at baseline. Older age [≥ 35 years; adjusted odds ratio (aOR) 1.9; 95% confidence interval (CI) 1.8-2.1] and male sex were associated with advanced HIV disease. Fifty per cent (7163/14 423) of individuals had at least two CD4 counts during the study period. Of those with an initial CD4 count ≥ 200 cells/µL, 4% (180/5061) experienced a decline in CD4 count to < 200 cells/µL; the majority of CD4 count declines were in virologically suppressed individuals and transient. CONCLUSIONS: One-quarter of HIV-positive individuals in Botswana still present with advanced HIV disease, highlighting the importance of baseline CD4 count measurement to identify this at-risk population. Few with a baseline CD4 count ≥ 200 cells/µL experienced a drop below 200 cells/µL, suggesting limited utility for ongoing CD4 monitoring.

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.