Outcomes of Reflex Cryptococcal Antigen (CrAg) Screening in Human Immunodeficiency Virus (HIV)-Positive Patients With CD4 Counts of 100-200 Cells/µL in Botswana.

Increasing the CD4-count threshold for cryptococcal antigen (CrAg) screening from ≤100 to ≤200 cells/µL resulted in a 3-fold increase in numbers screened. CrAg-prevalence was 3.5% at CD4 101-200 and 6.2% ≤100 cells/µL. Six-month mortality was 21.4% (9/42) in CrAg-positive CD4 ≤100 cells/µL and 3.2% (1/31) in CrAg-positive CD4 101-200 cells/µL.

Diagnostic Accuracy of the Biosynex CryptoPS Cryptococcal Antigen Semiquantitative Lateral Flow Assay in Patients with Advanced HIV Disease.

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 semiquantitative 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. In a prospective cohort of patients with AHD (CD4 cell count, ≤200/µl) receiving CD4 count testing, whole blood was tested for CrAg by CryptoPS and the IMMY LFA; the two assays were conducted by two different operators, each blind to the results of the other assay. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of CryptoPS were assessed against the IMMY LFA as a reference. CryptoPS low-titer (T1 band) and high-titer (T2 band) results were compared with IMMY LFA titers obtained through serial dilution. A total of 916 specimens were tested. The sensitivity of the CryptoPS assay was 61.0% (25/41) (95% confidence interval [95% CI], 44.5 to 75.8%), its specificity was 96.6% (845/875) (95% CI, 95.1 to 97.7%), its PPV was 45.5% (95% CI, 32.0 to 59.4%), and its NPV was 98.1% (95% CI, 97.0 to 98.9%). All (16/16) CryptoPS false-negative results were obtained for samples with IMMY titers of ≤1:160. Of 29 patients (30 specimens) who tested positive by CryptoPS but negative by the IMMY LFA, none developed cryptococcal meningitis over 3 months of follow-up without fluconazole. Median CrAg titers were 1:20 (interquartile range [IQR], 0 to 1:160) in CryptoPS T1-positive samples and 1:2,560 (IQR, 1:1,280 to 1:10,240) in T2-positive samples. We conclude that the diagnostic accuracy of the CryptoPS assay was suboptimal in the context of CrAg screening, with poor sensitivity at low CrAg titers. However, the CryptoPS assay reliably detected individuals with high titers, which are associated with poor outcomes.

Evaluation of a Novel Semiquantitative Cryptococcal Antigen Lateral Flow Assay in Patients with Advanced HIV Disease.

Higher cryptococcal antigen (CrAg) titers are strongly associated with mortality risk in individuals with HIV-associated cryptococcal disease. Rapid tests to quantify CrAg levels may provide important prognostic information and enable treatment stratification. We performed a laboratory-based validation of the IMMY semiquantitative cryptococcal antigen (CrAgSQ) lateral flow assay (LFA) against the current gold standard CrAg tests. We assessed the diagnostic accuracy of the CrAgSQ in HIV-positive individuals undergoing CrAg screening, determined the relationship between CrAgSQ scores and dilutional CrAg titers, assessed interrater reliability, and determined the clinical correlates of CrAgSQ scores. A total of 872 plasma samples were tested using both the CrAgSQ LFA and the conventional IMMY CrAg LFA, of which 692 were sequential samples from HIV-positive individuals undergoing CrAg screening and an additional 180 were known CrAg-positive plasma samples archived from prior studies. Interrater agreement in CrAgSQ reading was excellent (98.17% agreement, Cohen's kappa 0.962, P < 0.001). Using the IMMY CrAg LFA as a reference standard, CrAgSQ was 93.0% sensitive (95% confidence interval [CI] 80.9% to 98.5%) and 93.8% specific (95% CI, 91.7% to 95.6%). After reclassification of discordant results using CrAg enzyme immunoassay testing, the sensitivity was 98.1% (95% CI, 90.1% to 100%) and specificity 95.8% (95% CI, 93.9% to 97.2%). The median CrAg titers for semiquantitative score categories (1+ to 4+) were 1:10 (interquartile range [IQR], 1:5 to 1:20) in the CrAgSQ 1+ category, 1:40 (IQR, 1:20 to 1:80) in the CrAgSQ 2+ category, 1:640 (IQR, 1:160 to 1:2,560) in the CrAgSQ 3+ category, and 1:5,120 (IQR, 1:2,560 to 1:30,720) in the CrAgSQ 4+ category. Increasing CrAgSQ scores were strongly associated with 10-week mortality. The IMMY CrAgSQ test had high sensitivity and specificity compared to the results for the IMMY CrAg LFA and provided CrAg scores that were associated with both conventional CrAg titers and clinical outcomes.

Stroke and HIV in Botswana: A prospective study of risk factors and outcomes.

OBJECTIVE: HIV is associated with an increased risk of stroke, but there are sparse data on risk factors for stroke in people living with HIV in Sub-Saharan African. The goal of this study was to identify HIV-specific stroke characteristics and risk factors among adults in Botswana. METHODS: We conducted a prospective cohort study in Gaborone, Botswana from June 2015 to June 2017 comparing risk factors and outcomes among adults with and without HIV admitted for acute stroke. In addition, we conducted a case-control study comparing patients with HIV and stroke to outpatients with HIV and no history of stroke. RESULTS: A total of 52 patients with imaging-confirmed acute stroke were enrolled. Stroke patients with HIV were younger than those without HIV (median age 40 vs 54, p = .005). Hypertension was the most common risk factor identified in both HIV+ and HIV- groups, but was more common in patients without HIV (81% vs. 55%, p = .04). Patients with HIV were significantly more likely to have a small-vessel lacunar syndrome compared to patients without HIV (67% vs. 29%, p = .02). In the case-control analysis, patients with HIV and stroke were more likely to have hypertension than stroke-free controls (53% vs. 16%; OR 7.2, 95% CI 1.5-33.8, p = .01), and were more likely to drink alcohol (53% vs. 21%, OR 3.7, 95% CI 1.1-12.1, p = .03). CONCLUSIONS: Individuals with HIV present with strokes at younger ages than individuals without HIV. Among those with HIV, hypertension and alcohol use are significant risk factors for stroke.

Investigating Mediators of the Poor Pneumonia Outcomes of Human Immunodeficiency Virus-Exposed but Uninfected Children.

BACKGROUND: Human immunodeficiency virus-exposed but uninfected (HIV-EU) children have a higher mortality rate than the children of HIV-negative mothers (HIV-unexposed). Causal mediators of the poor health outcomes of HIV-EU children remain poorly defined. METHODS: We conducted a hospital-based prospective cohort study of children aged 1 to 23 months with clinically defined pneumonia. The children were recruited at a referral hospital in Gaborone, Botswana, between April 2012 and June 2016. The primary outcome, treatment failure at 48 hours, was assessed by an investigator blinded to the children's HIV-exposure status. We examined associations between HIV exposure and pneumonia outcomes in HIV-uninfected children. We next determined whether the effect of HIV exposure on outcomes was mediated by low-birth-weight status, nonbreastfeeding, malnutrition, in utero exposure to combination antiretroviral therapy, or pneumonia severity. RESULTS: A total of 352 HIV-uninfected children were included in these analyses, including 245 (70%) HIV-unexposed and 107 (30%) HIV-EU children. Their median age was 7.4 months, and 57% were male. Treatment failure occurred in 111 (32%) children, and 19 (5.4%) children died. HIV-EU children were more likely to fail treatment (risk ratio [RR], 1.57 [95% confidence interval (CI), 1.19-2.07]; P = .002) and had a higher in-hospital mortality rate (RR, 4.50 [95% CI, 1.86-10.85]; P = .001) than HIV-unexposed children. Nonbreastfeeding mediated 47% of the effect of HIV exposure on the risk of in-hospital death. CONCLUSIONS: HIV-EU children have worse pneumonia outcomes than HIV-unexposed children. Nonbreastfeeding mediates nearly half of the effect of HIV exposure on pneumonia mortality. Our findings provide additional evidence for a mortality benefit of breastfeeding by HIV-EU children.

The Nasopharyngeal Microbiota of Children With Respiratory Infections in Botswana.

BACKGROUND: Nearly half of child pneumonia deaths occur in sub-Saharan Africa. Microbial communities in the nasopharynx are a reservoir for pneumonia pathogens and remain poorly described in African children. METHODS: Nasopharyngeal swabs were collected from children with pneumonia (N = 204), children with upper respiratory infection symptoms (N = 55) and healthy children (N = 60) in Botswana between April 2012 and April 2014. We sequenced the V3 region of the bacterial 16S ribosomal RNA gene and used partitioning around medoids to cluster samples into microbiota biotypes. We then used multivariable logistic regression to examine whether microbiota biotypes were associated with pneumonia and upper respiratory infection symptoms. RESULTS: Mean ages of children with pneumonia, children with upper respiratory infection symptoms and healthy children were 8.2, 11.4 and 8.0 months, respectively. Clustering of nasopharyngeal microbiota identified 5 distinct biotypes: Corynebacterium/Dolosigranulum-dominant (23%), Haemophilus-dominant (11%), Moraxella-dominant (24%), Staphylococcus-dominant (13%) and Streptococcus-dominant (28%). The Haemophilus-dominant [odds ratio (OR): 13.55; 95% confidence interval (CI): 2.10-87.26], the Staphylococcus-dominant (OR: 8.27; 95% CI: 2.13-32.14) and the Streptococcus-dominant (OR: 39.97; 95% CI: 6.63-241.00) biotypes were associated with pneumonia. The Moraxella-dominant (OR: 3.71; 95% CI: 1.09-12.64) and Streptococcus-dominant (OR: 12.26; 95% CI: 1.81-83.06) biotypes were associated with upper respiratory infection symptoms. In children with pneumonia, HIV infection was associated with a lower relative abundance of Dolosigranulum (P = 0.03). CONCLUSIONS: Pneumonia and upper respiratory infection symptoms are associated with distinct nasopharyngeal microbiota biotypes in African children. A lower abundance of the commensal genus Dolosigranulum may contribute to the higher pneumonia risk of HIV-infected children.