Abstract:
Background:
Mother to child transmission (MTCT) of Human Immunodeficiency Virus (HIV) causes about 90% of newly infected infants and children. The risk MTCT of HIV without intervention ranges from 25 to 40% if breastfeeding is continued for two years. The use of antiretroviral (ARV) drugs for prophylaxis during pregnancy can reduce the transmission significantly. The use of sdNVPor any other short regimens containing one or two drugs however induces viral resistance and can lead to treatment failure when a woman subsequently starts ART for her health.
Objective: To assess the immunological response to Antiretroviral treatment of immuno- suppressed women previously exposed to Zidovudine or single dose Nevirapine prophylaxis for prevention of mother to child transmission of human immunodeficiency virus in Dar es salaam.
Method: A retrospectiveCohort study was conducted in four CTC – clinics in public hospitals, in Dar es Salaam from July 2012 to October 2012.Women currently on ART but previously exposed to ARV prophylaxis for PMTCT were compared to unexposed (naïve) women also on ART and determined the immunologic response.Semi structured questionnaire was used to collect social demographic characteristics information. Data management was done using the SPSS statistical program version 16.0.
Results
A total of 807 clients were analyzed, whereby 288 were exposed to either ZDV or sdNVP. Median CD4+ counts of exposed and unexposed were not comparable at baseline whereby there was statistical difference, as exposed group had higher median CD4+ counts 163 (IQR 89-206) as compared to the unexposed 124 (IQR 63-192) (p-value 0.000). At six months and twelve months the Median CD4+ counts changed the trend whereby the unexposed had slightly higher CD4+ counts as compared to exposed, although they were not statistically significant, (p-values 0.383 and 0.971 respectively). There was increase in median CD4+ counts of +70 and +164 cell/µl at six and twelve months of ART respectively in Exposed group, while in unexposed group the change was +126 and +196 cells/µl. These changes are with respect to the baseline CD4+ cells counts.
At six months 12.5% of women who were exposed had Immunological failure while only 4.2% of unexposed had immunological failure, which was statistically significant (0.000), and had three times higher chance of developing failure CI (1.86-5.60).
Conclusion
At baseline, six and twelve months of initiation of ART the statistical significant difference in CD4+ cell count levels was not observed among women exposed to the PMTCT prophylaxis and those who were unexposed.When immunological failure checked as per exposure the findings were statistically significant. Initiation of ART, within six months post exposure, contributed to the poorer CD4+ response significantly as well as immunological failure as compared to those who initiated beyond six months.
