Analysis of HIV early infant diagnosis data to estimate rates of perinatal HIV transmission in Zambia.
BACKGROUND
Mother-to-child transmission of HIV (MTCT) remains the most prevalent source of pediatric HIV infection. Most PMTCT (prevention of mother-to-child transmission of HIV) programs have concentrated monitoring and evaluation efforts on process rather than on outcome indicators. In this paper, we review service data from 28,320 children born to HIV-positive mothers to estimate MTCT rates.


METHODS
This study analyzed DNA PCR results and PMTCT data from perinatally exposed children zero to 12 months of age from five Zambian provinces between September 2007 and July 2010.


RESULTS
The majority of children (58.6%) had a PCR test conducted between age six weeks and six months. Exclusive breastfeeding (56.8%) was the most frequent feeding method. An estimated 45.9% of mothers were below 30 years old and 93.3% had disclosed their HIV status. In terms of ARV regimen for PMTCT, 32.7% received AZT+single dose NVP (sdNVP), 30.9% received highly active antiretroviral treatment (HAART), 19.6% received sdNVP only and 12.9% received no ARVs. Transmission rates at six weeks when ARVs were received by both mother and baby, mother only, baby only, and none were 5.8%, 10.5%, 15.8% and 21.8% respectively. Transmission rates at six weeks where mother received HAART, AZT+sd NVP, sdNVP, and no intervention were 4.2%, 6.8%, 8.7% and 20.1% respectively. Based on adjusted analysis including ARV exposures and non ARV-related parameters, lower rates of positive PCR results were associated with 1) both mother and infant receiving prophylaxis, 2) children never breastfed and 3) mother being 30 years old or greater. Overall between September 2007 and July 2010, 12.2% of PCR results were HIV positive. Between September 2007 and January 2009, then between February 2009 and July 2010, proportions of positive PCR results were 15.1% and 11% respectively, a significant difference.


CONCLUSIONS
The use of ARV drugs reduces vertical transmission of HIV in a program setting. Non-chemoprophylactic factors also play a significant role in HIV transmission. The overall change in the proportions of positive PCR results over time is more likely an indication of better PMTCT implementation. Determination of the outcomes of PMTCT in program settings is feasible but requires accurate documentation and analysis.
FHI 360, Durham, North Carolina, United States of America.
Kwasi
K
Torpey
Justin
J
Mandala
Prisca
P
Kasonde
Gail
G
Bryan-Mofya
Maximillian
M
Bweupe
Jonathan
J
Mukundu
Chilunje
C
Zimba
Catherine
C
Mwale
Hilary
H
Lumano
Michael
M
Welsh
D000328:Adult; D017677:Age Distribution; D019380:Anti-HIV Agents / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use; D036861:Delivery, Obstetric / Q000706:statistics & numerical data; D042241:Early Diagnosis; D005260:Female; D015658:HIV Infections / Q000151:congenital* / Q000175:diagnosis* / Q000188:drug therapy / Q000635:transmission; D015497:HIV-1 / Q000187:drug effects / Q000235:genetics / Q000502:physiology*; D006801:Humans; D007223:Infant; D018445:Infectious Disease Transmission, Vertical / Q000517:prevention & control / Q000706:statistics & numerical data*; D008297:Male; D018811:Maternal Exposure; D015024:Zambia / Q000453:epidemiology
D019380:Anti-HIV Agents