Universal combination antiretroviral regimens to prevent mother-to-child transmission of HIV in rural Zambia: a two-round cross-sectional study

To evaluate if a pilot programme to prevent mother-to-child transmission (PMTCT) of the human immunodeficiency virus (HIV) was associated with changes in early childhood survival at the population level in rural Zambia

Non-virologic algorithms for predicting HIV infection among HIV-exposed infants under 12 weeks of age

Early initiation of antiretroviral therapy (ART) has been shown to reduce mortality among perinatally HIV-infected infants, but availability of virologic testing remains limited in many settings

Estimating Loss to Follow-Up in HIV-Infected Patients on Antiretroviral Therapy: The Effect of the Competing Risk of Death in Zambia and Switzerland

BACKGROUND: Loss to follow-up (LTFU) is common in antiretroviral therapy (ART) programmes. Mortality is a competing risk (CR) for LTFU; however, it is often overlooked in cohort analyses. We examined how the CR of death affected LTFU estimates in Zambia and Switzerland. METHODS AND FINDINGS: HIV-infected patients aged ≥18 years who started ART 2004-2008 in observational cohorts in Zambia and Switzerland were included. We compared standard Kaplan-Meier curves with CR cumulative incidence. We calculated hazard ratios for LTFU across CD4 cell count strata using cause-specific Cox models, or Fine and Gray subdistribution models, adjusting for age, gender, body mass index and clinical stage. 89,339 patients from Zambia and 1,860 patients from Switzerland were included. 12,237 patients (13.7%) in Zambia and 129 patients (6.9%) in Switzerland were LTFU and 8,498 (9.5%) and 29 patients (1.6%), respectively, died. In Zambia, the probability of LTFU was overestimated in Kaplan-Meier curves: estimates at 3.5 years were 29.3% for patients starting ART with CD4 cells <100 cells/µl and 15.4% among patients starting with ≥350 cells/µL. The estimates from CR cumulative incidence were 22.9% and 13.6%, respectively. Little difference was found between naïve and CR analyses in Switzerland since only few patients died. The results from Cox and Fine and Gray models were similar: in Zambia the risk of loss to follow-up and death increased with decreasing CD4 counts at the start of ART, whereas in Switzerland there was a trend in the opposite direction, with patients with higher CD4 cell counts more likely to be lost to follow-up. CONCLUSIONS: In ART programmes in low-income settings the competing risk of death can substantially bias standard analyses of LTFU. The CD4 cell count and other prognostic factors may be differentially associated with LTFU in low-income and high-income settings

Comparative studies on the biochemical properties of the malic enzymes from Trypanosoma cruzi and Trypanosoma brucei.

Comparative studies showed that, like Trypanosoma cruzi, Trypanosoma brucei exhibits functional cytosolic and mitochondrial malic enzymes (MEs), which are specifically linked to NADP. Kinetic studies provided evidence that T. cruzi and T. brucei MEs display similarly high affinities towards NADP(+) and are also almost equally efficient in catalyzing the production of NADPH. Nevertheless, in contrast to the cytosolic ME from T. cruzi, which is highly activated by l-aspartate (over 10-fold), the T. brucei homologue is slightly more active (50%) in the presence of this amino acid. In T. brucei, both isozymes appear to be clearly more abundant in the insect stage, although they can be immunodetected in the bloodstream forms. By contrast, in T. cruzi the expression of the mitochondrial ME seems to be clearly upregulated in amastigotes, whereas the cytosolic isoform appears to be more abundant in the insect stages of the parasite. It might be hypothesized that in those environments where glucose is very low or absent, these pathogens depend on NADP-linked dehydrogenases such as the MEs for NADPH production, as in those conditions the pentose phosphate pathway cannot serve as a source of essential reducing power

Declining HIV prevalence among young pregnant women in Lusaka, Zambia

OBJECTIVE: HIV prevention has been ongoing in Lusaka for many years. Recent reports suggest a possible decline in HIV sero-incidence in Zambia and some neighbouring countries. This study aimed to examine trends in HIV seroprevalence among pregnant and parturient women between 2002 and 2006. METHODS: We analysed HIV seroprevalence trends from two Lusaka sources: (i) antenatal data from a city-wide programme to prevent mother-to-child HIV transmission, and (ii) delivery data from two anonymous unlinked cord-blood surveillances performed in 2003 and again in 2005-2006, where specimens from > 97% of public-sector births in each period were obtained and analysed. FINDINGS: Between July 2002 and December 2006, the Lusaka district tested 243 302 antenatal women for HIV; 54 853 (22.5%) were HIV infected. Over this period, the HIV seroprevalence among antenatal attendees who were tested declined steadily from 24.5% in the third quarter of 2002 to 21.4% in the last quarter of 2006 (P < 0.001). The cord-blood surveillances were conducted between June and August 2003 and again between October 2005 and January 2006. Overall HIV seroprevalence declined from 25.7% in 2003 to 21.8% in 2005-2006 (P = 0.001). Among women < 17 years of age, seroprevalence declined from 12.1% to 7.7% (P = 0.015). CONCLUSION: HIV seroprevalence appears to be declining among antenatal and parturient women in Lusaka. The decline is most dramatic among women < " 17 years of age, suggesting a reduction in sero-incidence in this important age group

Field effectiveness of combination antiretroviral prophylaxis for the prevention of mother-to-child HIV transmission in rural Zambia

To evaluate the effectiveness of maternal combination antiretroviral prophylaxis for prevention of mother-to-child transmission of HIV (PMTCT) in a program setting

Universal combination antiretroviral regimens to prevent mother-to-child transmission of HIV in rural Zambia: a two-round cross-sectional study

OBJECTIVE: To evaluate if a pilot programme to prevent mother-to-child transmission (PMTCT) of the human immunodeficiency virus (HIV) was associated with changes in early childhood survival at the population level in rural Zambia. METHODS: Combination antiretroviral regimens were offered to pregnant and breastfeeding, HIV-infected women, irrespective of immunological status, at four rural health facilities. Twenty-four-month HIV-free survival among children born to HIV-infected mothers was determined before and after PMTCT programme implementation using community surveys. Households were randomly selected and women who had given birth in the previous 24 months were asked to participate. Mothers were tested for HIV antibodies and children born to HIV-infected mothers were tested for viral deoxyribonucleic acid. Multivariable models were used to determine factors associated with child HIV infection or death. FINDINGS: In the first survey (2008–2009), 335 of 1778 women (18.8%) tested positive for HIV. In the second (2011), 390 of 2386 (16.3%) tested positive. The 24-month HIV-free survival in HIV-exposed children was 0.66 (95% confidence interval, CI: 0.63–0.76) in the first survey and 0.89 (95% CI: 0.83–0.94) in the second. Combination antiretroviral regimen use was associated with a lower risk of HIV infection or death in children (adjusted hazard ratio: 0.33, 95% CI: 0.15–0.73). Maternal knowledge of HIV status, use of HIV tests and use of combination regimens during pregnancy increased between the surveys. CONCLUSION: The PMTCT programme was associated with an increased HIV-free survival in children born to HIV-infected mothers. Maternal utilization of HIV testing and treatment in the community also increased