Publications

OBJECTIVE

Many people living with HIV in sub-Saharan Africa desire biological children. Implementation of HIV prevention strategies that support the reproductive goals of people living with HIV while minimizing HIV transmission risk to sexual partners and future children requires a comprehensive understanding of pregnancy in this population. We analyzed prospective cohort data to determine pregnancy incidence and predictors among HIV-positive women initiating antiretroviral therapy (ART) in a setting with high HIV prevalence and fertility.

METHODS

Participants were enrolled in the Uganda AIDS Rural Treatment Outcomes (UARTO) cohort of HIV-positive individuals initiating ART in Mbarara. Bloodwork (including CD4 cells/mm(3), HIV viral load) and questionnaires (including socio-demographics, health status, sexual behavior, partner dynamics, HIV history, and self-reported pregnancy) were completed at baseline and quarterly. Our analysis includes 351 HIV-positive women (18-49 years) who enrolled between 2005-2011. We measured pregnancy incidence by proximal and distal time relative to ART initiation and used multivariable Cox proportional hazards regression analysis (with repeated events) to identify baseline and time-dependent predictors of pregnancy post-ART initiation.

RESULTS

At baseline (pre-ART initiation), median age was 33 years [IQR: 27-37] and median prior livebirths was four [IQR: 2-6]. 38% were married with 61% reporting HIV-positive spouses. 73% of women had disclosed HIV status to a primary sexual partner. Median baseline CD4 was 137 cells/mm(3) [IQR: 81-207]. At enrolment, 9.1% (31/342) reported current pregnancy. After ART initiation, 84 women experienced 105 pregnancies over 3.8 median years of follow-up, yielding a pregnancy incidence of 9.40 per 100 WYs. Three years post-ART initiation, cumulative probability of at least one pregnancy was 28% and independently associated with younger age (Adjusted Hazard Ratio (AHR): 0.89/year increase; 95%CI: 0.86-0.92) and HIV serostatus disclosure to primary sexual partner (AHR: 2.45; 95%CI: 1.29-4.63).

CONCLUSIONS

Nearly one-third of women became pregnant within three years of initiating ART, highlighting the need for integrated services to prevent unintended pregnancies and reduce periconception-related risks for HIV-infected women choosing to conceive. Association with younger age and disclosure suggests a role for early and couples-based safer conception counselling.

Coinfection with malaria and nontyphoidal Salmonella serotypes (NTS) can cause life-threatening bacteremia in humans. Coinfection with malaria is a recognized risk factor for invasive NTS, suggesting that malaria impairs intestinal barrier function. Here, we investigated mechanisms and strategies for prevention of coinfection pathology in a mouse model. Our findings reveal that malarial-parasite-infected mice, like humans, develop L-arginine deficiency, which is associated with intestinal mastocytosis, elevated levels of histamine, and enhanced intestinal permeability. Prevention or reversal of L-arginine deficiency blunts mastocytosis in ileal villi as well as bacterial translocation, measured as numbers of mesenteric lymph node CFU of noninvasive Escherichia coli Nissle and Salmonella enterica serotype Typhimurium, the latter of which is naturally invasive in mice. Dietary supplementation of malarial-parasite-infected mice with L-arginine or L-citrulline reduced levels of ileal transcripts encoding interleukin-4 (IL-4), a key mediator of intestinal mastocytosis and macromolecular permeability. Supplementation with L-citrulline also enhanced epithelial adherens and tight junctions in the ilea of coinfected mice. These data suggest that increasing L-arginine bioavailability via oral supplementation can ameliorate malaria-induced intestinal pathology, providing a basis for testing nutritional interventions to reduce malaria-associated mortality in humans.