High prevalence of cryptococcal antigenaemia amongst asymptomatic advanced HIV patients in Pune, India.

BACKGROUND: The World Health Organization recommends routine cryptococcal antigen (CrAg) screening in advanced AIDS patients initiating antiretroviral treatment (ART). India has yet to adopt this strategy as the burden of cryptococcal antigenaemia is unknown. METHODS: A prospective study was conducted in a large public sector ART centre and the inpatient wards of Sassoon Hospital, Pune, India. All consenting patients> 18 years of age with CD4 count <100 cells/mm3 were screened for CrAg by latex agglutination assay. Those with positive CrAg underwent cerebrospinal fluid analysis, chest radiograph and abdominal ultrasound to rule out cryptococcal disease. The impact of CrAg positivity on all-cause mortality was assessed by logistic regression analysis. RESULTS: Amongst 208 AIDS patients with CD4 cells <100 cells/mm3 who underwent CrAg testing, median age was 40 (interquartile range [IQR], 35-49) years, 134 (64%) were male and median CD4 count was 64.5 cells/mm3 (IQR, 37-82). Overall, 16 (8%, 95% confidence interval [CI], 4-12) patients were positive for CrAg, of which 8 (50%) had CD4 cells <50 cells/mm3 and 3 (19%) CrAg-positive patients had incidental cryptococcal meningitis. At 6-month follow-up, the case fatality rate was higher amongst CrAg-positive patients (38%) compared with CrAg-negative patients (18%) (P = 0.06). After adjusting for age, sex, CD4 count and ART, there was a trend towards increased all-cause mortality (adjusted OR, 3.18, 95% CI, 0.60-16.88,P= 0.17). CONCLUSIONS: We found an 8% prevalence of cryptococcaemia amongst adult AIDS patients with CD4 cells <100 cells/mm3. Given the high fatality rates observed, routine screening for CrAg should be considered for all Indian persons with advanced HIV disease.

Pregnancy differentially impacts performance of latent tuberculosis diagnostics in a high-burden setting.

BACKGROUND: Targeted screening for latent TB infection (LTBI) in vulnerable populations is a recommended TB control strategy. Pregnant women are at high risk for developing TB and likely to access healthcare, making pregnancy an important screening opportunity in developing countries. The sensitivity of the widely-used tuberculin skin test (TST), however, may be reduced during pregnancy. METHODS: We performed a cross-sectional study comparing the TST with the QuantiFERON Gold In-tube (QGIT) in 401 HIV-negative women presenting antepartum (n = 154), at delivery (n = 148), or postpartum (n = 99) to a government hospital in Pune, India. A subset of 60 women enrolled during pregnancy was followed longitudinally and received both tests at all three stages of pregnancy. RESULTS: The QGIT returned significantly more positive results than the TST. Of the 401 women in the cross-sectional study, 150 (37%) had a positive QGIT, compared to 59 (14%) for the TST (p<0.005). Forty-nine (12%) did not have their TST read. Of 356 who had both results available, 46 (13%) were concordant positive, 91 (25%) were discordant (12 (3%) TST+/QGIT-; 79 (22%) TST-/QGIT+), and 206 (57%) concordant negative. Comparison by stage of pregnancy revealed that QGIT percent positivity remained stable between antepartum and delivery, unlike TST results (QGIT 31-32% vs TST 11-17%). Median IFN-γ concentration was lower at delivery than in antepartum or postpartum (1.66 vs 2.65 vs 8.99 IU/mL, p = 0.001). During postpartum, both tests had significantly increased positives (QGIT 31% vs 32% vs 52%, p = 0.01; TST 17% vs 11% vs 25%, p<0.005). The same trends were observed in the longitudinal subset. CONCLUSIONS: Timing and choice of LTBI test during pregnancy impact results. QGIT was more stable and more closely approximated the LTBI prevalence in India. But pregnancy stage clearly affects both tests, raising important questions about how the complex immune changes brought on by pregnancy may impact LTBI screening.