Background:  We recently documented a higher-than-suspected prevalence of HIV infection among pregnant women and a high mother-to-child HIV transmission rate at the Tijuana General Hospital in Baja California, Mexico. This study evaluated HIV-related disease progression in children identified through this program.

Methods:  Children diagnosed with HIV infection and followed at the Pediatric HIV clinic at Tijuana General Hospital between 1998 and 2005 were observed longitudinally for CD4 cell percentage, plasma HIV RNA log₁₀, ART, morbidity, and death. Median survival was calculated by the Kaplan-Meier method.

Results:  A total of 65 children were followed during the study period:  55% were boys; mean age at HIV diagnosis was 2.6 years (±3.54), 55% were diagnosed before their second birthday. We diagnosed 41 cases (63%) with HIV between 2002 and 2005:  32 cases (49%) were CDC classification group C at the time of HIV diagnosis and 42 cases (62%) had ≥1 admission to the hospital prior to HIV diagnosis. Pneumonia was the most common morbidity (37%) at or prior to HIV diagnosis, followed by failure to thrive (20%) and Pneumocystis pneumonia (PCP; 12%). Mean CD4 percentage was 19%, 23%, 23%, and 27% for the years 1998-1999, 2000-2001, 2002-2003, and 2004-2005, respectively (p = 0.3). HIV RNA log₁₀ did not change over time and was 5.4, 5.2, 5.4, and 5.4 for the years 1998-1999, 2000-2001, 2002-2003, and 2004-2005, respectively (p = 0.9). Triple drug combination ART was used in 50% of patients during 1998-1999 and during 2000 and increased to 82% for the period between 2001 and 2005. Overall mortality was 29% (19 of 65) with pneumonia as the most common cause of death (58% of all deaths) followed by PCP, tuberculosis, and meningitis with 10% each. When stratified by year of diagnosis, no temporal trends were observed in morbidity or CDC clinical classification at the time of HIV diagnosis. The mortality rate decreased significantly over time, from 18.8% in 2000-2001, to 14.3% in 2002-2003 to 5.6% in 2004-2005 (p = 0.0002). Mean age at death was 3 years (±4.08). Kaplan Meier survival analysis showed that the median survival was 6.85 years; 75% were alive by their second birthday and 58% survived by their fifth birthday.

Conclusions:  These findings indicate a high morbidity at the time of HIV diagnosis and a declining mortality in this cohort of perinatally HIV-infected children in Baja California, Mexico.