Presumptive diagnosis of severe HIV infection to determine the need for antiretroviral therapy in children less than 18 months of age.

OBJECTIVE: To develop a new algorithm for the presumptive diagnosis of severe disease associated with human immunodeficiency virus (HIV) infection in children less than 18 months of age for the purpose of identifying children who require antiretroviral therapy (ART). METHODS: A conditional probability model was constructed and non-virologic parameters in various combinations were tested in a hypothetical cohort of 1000 children aged 6 weeks, 6 months and 12 months to assess the sensitivity, specificity, and positive and negative predictive values of these algorithms for identifying children in need of ART. The modelled parameters consisted of clinical criteria, rapid HIV antibody testing and CD4+ T-lymphocyte (CD4) count. FINDINGS: In children younger than 18 months, the best-performing screening algorithm, consisting of clinical symptoms plus antibody testing plus CD4 count, showed a sensitivity ranging from 71% to 80% and a specificity ranging from 92% to 99%. Positive and negative predictive values were between 61% and 97% and between 95% and 96%, respectively. In the absence of virologic tests, this alternate algorithm for the presumptive diagnosis of severe HIV disease makes it possible to correctly initiate ART in 91% to 98% of HIV-positive children who are at highest risk of dying. CONCLUSION: The algorithms presented in this paper have better sensitivity and specificity than clinical parameters, with or without rapid HIV testing, for the presumptive diagnosis of severe disease in HIV-positive children less than 18 months of age. If implemented, they can increase the number of HIV-positive children successfully initiated on ART.

Sildenafil improves cardiac output and exercise performance during acute hypoxia, but not normoxia.

Sildenafil causes pulmonary vasodilation, thus potentially reducing impairments of hypoxia-induced pulmonary hypertension on exercise performance at altitude. The purpose of this study was to determine the effects of sildenafil during normoxic and hypoxic exercise. We hypothesized that 1) sildenafil would have no significant effects on normoxic exercise, and 2) sildenafil would improve cardiac output, arterial oxygen saturation (SaO2), and performance during hypoxic exercise. Ten trained men performed one practice and three experimental trials at sea level (SL) and simulated high altitude (HA) of 3,874 m. Each cycling test consisted of a set-work-rate portion (55% work capacity: 1 h SL, 30 min HA) followed immediately by a time trial (10 km SL, 6 km HA). Double-blinded capsules (placebo, 50, or 100 mg) were taken 1 h before exercise in a randomly counterbalanced order. For HA, subjects also began breathing hypoxic gas (12.8% oxygen) 1 h before exercise. At SL, sildenafil had no effects on any cardiovascular or performance measures. At HA, sildenafil increased stroke volume (measured by impedance cardiography), cardiac output, and SaO2 during set-work-rate exercise. Sildenafil lowered 6-km time-trial time by 15% (P<0.05). SaO2 was also higher during the time trial (P<0.05) in response to sildenafil, despite higher work rates. Post hoc analyses revealed two subject groups, sildenafil responders and nonresponders, who improved time-trial performance by 39% (P<0.05) and 1.0%, respectively. No dose-response effects were observed. During cycling exercise in acute hypoxia, sildenafil can greatly improve cardiovascular function, SaO2, and performance for certain individuals.

Five-year outcomes of initial patients treated in Botswana's National Antiretroviral Treatment Program.

BACKGROUND: Antiretroviral treatment (ART) initiatives have now been established in many sub-Saharan African countries showing early benefits. To date, few results are available concerning long-term clinical outcomes in these treatment programs. METHODS: Response to ART is described in the first HIV-1C-infected adults enrolled in the Botswana Antiretroviral Treatment Program in 2002. Data analysis was conducted on available longitudinal data up to 1st April 2007. RESULTS: Six hundred thirty-three severely immunodeficient patients with a median CD4+ cell count of 67 cells/microl were initiated on non-nucleoside reverse transcriptase inhibitor-based combination ART and followed for a median of 41.9 months. The median CD4+ cell count increases were 169, 302, and 337 cells/microl at 1, 3, and 5 years, respectively. The percentages of patients with a viral load of less than 400 copies/ml at 1, 3, and 5 years were 91.3, 90.1, and 98.3%, respectively. Seventy-five percent of patients did not miss a single, or missed only one, monthly ART pickup per year with a mean pickup rate of 92.5%. The Kaplan-Meier survival estimates [95% confidence interval (CI)] at 1, 3, and 5 years were 82.7% (81.2 and 84.3%), 79.3% (77.6 and 81.0%), and 79.0% (77.3 and 80.7%), respectively. At 6 months, the risk of treatment modification for anemia was 6.94% (5.9 and 8.0%) for cutaneous hypersensitivity reactions, 1.3% (0.8 and 1.7%), and 1.1% (0.7 and 1.6%) for hepatotoxicity. CONCLUSION: This initial group of adults on ART in Botswana had excellent sustained immunologic, virologic, and clinical outcomes for up to 5 years of follow-up with low mortality among those surviving into the second year of ART.