Detection of bacterial enteropathogens is associated with increased mortality in children in sub-Saharan Africa. Unfortunately, most children with these infections do not have bloody stools, and bloody dysentery was not found to be associated with worse outcomes. Clinical trials evaluating outcomes associated with more aggressive diagnostic strategies in children presenting with severe acute gastroenteritis in sub-Saharan Africa should be undertaken.

Background: High cryptococcal antigen (CrAg) titers in blood are associated with subclinical meningitis and mortality in CrAg-positive individuals with advanced HIV-disease (AHD). We evaluated a novel semi-quantitative lateral flow assay (LFA), CryptoPS, that may be able to identify individuals with high CrAg titers in a cohort of AHD patients undergoing CrAg screening. Methods: In a prospective cohort of patients with AHD (CD4 ≤200 cells/μL) receiving CD4 count testing, CryptoPS and IMMY LFA CrAg testing were performed on whole blood by two operators blinded to results of the other assay. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of CryptoPS were assessed against IMMY LFA as a reference. CryptoPS low-titer (T1 band) and high-titer (T2 band) results were compared against IMMY LFA titers obtained through serial dilution. Results: 916 specimens were tested. Sensitivity of the CryptoPS assay was 61.0% (25/41, 95% confidence interval [95%CI]: 44.5-75.8), specificity 96.6% (845/875, 95%CI: 95.1-97.7), PPV 45.5% (95%CI: 32.0-59.4), and NPV 98.1% (95%CI: 97.0-98.9). All (16/16) CryptoPS false-negatives were samples with IMMY titers ≤1:160. Of 29 patients (30 specimens) who tested positive on CryptoPS but negative on IMMY LFA, none developed cryptococcal meningitis over 3-months follow-up without fluconazole. Median CrAg titers were 1:20 (interquartile range [IQR] 0-1:160) in CryptoPS T1-positive samples and 1:2560 (IQR 1:1280-1:10240) in T2-positives. Conclusions: Diagnostic accuracy of the CryptoPS assay was sub-optimal in the context of CrAg screening, with poor sensitivity at low CrAg titers. However, the CryptoPS assay reliably detected individuals with high titers associated with poor outcomes.

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.

Background Evidence to inform cryptococcal antigen (CrAg)–screening guidelines among ART-experienced populations is lacking. We performed a study evaluating the utility of reflex CrAg screening in Gaborone, Botswana. Methods CD4 count data were collected from the HIV reference laboratory from 2014–2016. CrAg screening was performed on samples with CD4 ≤100 cells/µL beginning January 2015. The proportion of CD4 counts ≤100 cells/µL was determined and the frequency of repeat CrAg testing described. Analyses ascertained the impact of ART status on CrAg prevalence and outcomes, and whether CrAg titers could be used for risk stratification. Results Overall, 5.6% (3335/59 300) of individuals tested had CD4 ≤100 cells/μL; 2108 samples with CD4 ≤100 cells/μL from 1645 unique patients were CrAg tested. Over half of samples were from ART-experienced individuals: 40.9% (863) on ART and 12.1% (255) defaulters; 22% (463) of CrAg tests were on repeat samples. CrAg prevalence was 4.8% (72/1494; 95% CI, 3.8–6.0%) among outpatients and 21.9% (32/151; 95% CI, 15.3–28.5%) among inpatients. CrAg prevalence rates did not differ by ART status, but 6-month mortality was significantly lower in CrAg-positive individuals on ART at screening. Ten CrAg positives were identified through repeat testing. A CrAg titer cutoff ≥1:80 provided the best discrimination for 6-month survival. Conclusions CrAg-positivity rates in an ART-experienced population were comparable to those seen in ART-naive populations. Repeat screening identified individuals who seroconverted to CrAg positivity and were at risk of cryptococcal disease. CrAg titers ≥1:80 can help identify the individuals at highest risk of death for more intensive management.