Abstract
BACKGROUND: Few studies have reported CD4%- and age-stratified rates of World Health Organization Stage 3 (WHO3) events, World Health Organization Stage 4 (WHO4) events, tuberculosis (TB) and mortality in HIV-infected infants before initiation of antiretroviral therapy. METHODS: HIV-infected children enrolled before 1 year of age in the International Epidemiologic Databases to Evaluate AIDS East Africa region (October 1, 2002, to November, 2008) were included. We estimated incidence rates of earliest clinical event (WHO3, WHO4 and TB), before antiretroviral therapy initiation per local guidelines, stratified by current age (< or ≥6 months) and current CD4% (<15%, 15-24%, ≥25%). CD4%-stratified mortality rates were estimated separately for children who did not experience a clinical event ("background" mortality) and for children who experienced an event, including "acute" mortality (≤30 days post event) and "later" mortality (>30 days post event). RESULTS: Among 847 children (median enrollment age: 4.8 months; median pre-antiretroviral therapy follow up: 10.8 months; 603 (71%) with ≥1 CD4% recorded), event rates were comparable for those aged <6 and ≥6 months. Current CD4% was associated with risk of WHO4 events for children <6 months of age and with all evaluated events for children ≥6 months old (P < 0.05). "Background" mortality was 3.7-8.4/100 person-years (PY). "Acute" mortality (≤30 days post event) was 33.8/100 PY (after TB) and 41.1/100 PY (after WHO3 or WHO4). "Later" mortality (>30 days post event) ranged by CD4% from 4.7 to 29.1/100 PY. CONCLUSIONS: In treatment-naïve, HIV-infected infants, WHO3, WHO4 and TB events were common before and after 6 months of age and led to substantial increases in mortality. Early infant HIV diagnosis and treatment are critically important, regardless of CD4%.