Antenatal and delivery practices and neonatal mortality amongst women with institutional and non-institutional deliveries in rural Zimbabwe: observational data from a cluster randomized trial

BACKGROUND

Despite achieving relatively high rates of antenatal care, institutional delivery, and HIV antiretroviral therapy for women during pregnancy, neonatal mortality has remained stubbornly high in Zimbabwe. Clearer understanding of causal pathways is required to inform effective interventions.

METHODS

This study was a secondary analysis of data from the Sanitation Hygiene Infant Nutrition Efficacy (SHINE) trial, a cluster-randomized community-based trial among pregnant women and their infants, to examine care during institutional and non-institutional deliveries in rural Zimbabwe and associated birth outcomes.

RESULTS

Among 4423 pregnant women, 529 (11.9%) delivered outside a health institution; hygiene practices were poorer and interventions to minimise neonatal hypothermia less commonly utilised for these deliveries compared to institutional deliveries. Among 3441 infants born in institutions, 592 (17.2%) were preterm (< 37 weeks gestation), while 175/462 (37.9%) infants born outside health institutions were preterm (RR: 2.20 (1.92, 2.53). Similarly, rates of stillbirth [1.2% compared to 3.0% (RR:2.38, 1.36, 4.15)] and neonatal mortality [2.4% compared to 4.8% (RR: 2.01 1.31, 3.10)] were higher among infants born outside institutions. Among mothers delivering at home who reported their reason for having a home delivery, 221/293 (75%) reported that precipitous labor was the primary reason for not having an institutional delivery while 32 (11%), 34 (12%), and 9 (3%), respectively, reported distance to the clinic, financial constraints, and religious/personal preference.

CONCLUSIONS

Preterm birth is common among all infants in rural Zimbabwe, and extremely high among infants born outside health institutions. Our findings indicate that premature onset of labor, rather than maternal choice, may be the reason for many non-institutional deliveries in low-resource settings, initiating a cascade of events resulting in a two-fold higher risk of stillbirth and neonatal mortality amongst children born outside health institutions. Interventions for primary prevention of preterm delivery will be crucial in reducing neonatal mortality in Zimbabwe.

TRIAL REGISTRATION

The trial is registered with ClinicalTrials.gov, number NCT01824940.

MN and IIIB recombinant glycoprotein 120 vaccine-induced binding antibodies to native envelope glycoprotein of human immunodeficiency virus type 1 primary isolates. National Institute of Allergy and Infectious Disease Aids Vaccine Evaluation Group

The ability of antibody induced by MN and IIIB recombinant gp120 (rgp120) human immunodeficiency virus type 1 (HIV-1) vaccines to bind to oligomeric native HIV-1 envelope glycoproteins of primary isolates of HIV-1 was measured by flow cytometric indirect immunofluorescence assay (FIFA) in 25 uninfected, healthy adults. After three immunizations, MN rgp120 HIV-1 vaccine given alone and coadministered with IIIB rgp120 HIV-1 vaccine elicited antibody that bound to cells infected with each of a panel of six subtype B strains of HIV-1. Lower levels of vaccine-induced binding antibody were detected against envelope subtype A, D, and (EA) strains of HIV-1 than against subtype B strains. Priming immunization with IIIB rgp120 HIV-1 vaccine alone induced low levels of antibody capable of binding to envelope glycoprotein of primary isolate strains of HIV-1, and booster immunizations with MN rgp120 HIV-1 vaccine resulted in much higher antibody levels. We conclude that MN rgp120 HIV-1 vaccine was an effective inducer of antibody to native envelope glycoproteins of antigenically diverse primary isolates of HIV-1.

HIV-1MN recombinant glycoprotein 160 vaccine-induced cellular and humoral immunity boosted by HIV-1MN recombinant glycoprotein 120 vaccine. National Institute of Allergy and Infectious Diseases AIDS Vaccine Evaluation Group

We evaluated prime-boost immunization with two recombinant envelope glycoprotein subunit vaccines (HIV-1MN recombinant gp160 vaccine in alum adjuvant [MN rgp160] and HIV-1MN recombinant gp120 vaccine in alum adjuvant [MN rgp120]) for safety and immunogenicity in healthy, HIV-1-uninfected adults. The rationale was to combine the helper T cell memory and binding antibody responses typically induced by rgp160 vaccines with the superior neutralizing antibody responses induced by rgp120 vaccines. In a double-blinded, controlled trial, volunteers were randomly assigned to receive MN rgp160 or adjuvant placebo, and a subset later received MN rgp120. The two vaccines were safe, but reactions to MN rgp160 and its adjuvant placebo exceeded those to MN rgp120. MN rgp160 induced IgG binding antibodies, including all IgG subclasses, to MN rgp160 in all vaccine recipients. HIV-1MN-neutralizing and anti-V3 MN peptide-binding antibodies were observed in a majority of volunteers after the fourth MN rgp160 immunization, but at lower levels compared with immunization with MN rgp120 in historical controls. HIV-1-binding, neutralizing, and fusion inhibition antibodies were boosted to the highest levels among MN rgp160 recipients after MN rgp120 booster injections. MN rgp120 boosting appeared to alter the distribution of MN rgp160 vaccine-induced, anti-MN rgp160 IgG subclass antibodies. MN rgp160 induced helper T cell memory, measured by lymphocyte proliferation, Thl and Th2 cytokine production, and skin testing. Strategies including both subunit vaccines may help maximize antibody and helper T cell memory responses to HIV-1 envelope glycoprotein.

Recombinant gp160 vaccination schedule and MHC HLA type as factors influencing cellular responses to HIV-1 envelope glycoprotein. NIAID AIDS Vaccine Clinical Trials Network

This study assessed (1) T-cell responses following vaccination of HIV-1 negative volunteers with HIV-1LAI recombinant gp160 (rgp160) vaccine, and (2) effects of vaccine injection schedule and MHC HLA type on those responses. In one trial, volunteers received rgp160 in two accelerated schedules (Groups 1 and 2). In the other trial, volunteers received rgp160 vaccine at 0, 1, 6, and 12 months and some received vaccine at 18 months (Groups 3 and 4). Peripheral blood mononuclear cells (PBMC) from vaccinees in Groups 3 and 4 were stimulated by more peptides representing envelope glycoprotein T-cell epitopes than Groups 1 and 2 (p = 0.01). Transient anti-envelope glycoprotein CTL activity was more frequently detectable in Groups 1 and 2 (p = 0.03). MHC HLA-Cw7, DR1 and DQw1 alleles appeared to be associated with PBMC responses to envelope glycoprotein.