Analysis of risk factors for infant mortality in the 1992-3 and 2002-3 birth cohorts in rural Guinea-Bissau

<div><p>Introduction</p><p>Though still high, the infant mortality rate in Guinea-Bissau has declined. We aimed to identify risk factors including vaccination coverage, for infant mortality in the rural population of Guinea-Bissau and assess whether these risk factors changed from 1992–3 to 2002–3.</p><p>Methods</p><p>The Bandim Health Project (BHP) continuously surveys children in rural Guinea-Bissau. We investigated the association between maternal and infant factors (especially DTP and measles coverage) and infant mortality. Hazard ratios (HR) were calculated using Cox regression. We tested for interactions with sex, age groups (defined by current vaccination schedule) and cohort to assess whether the risk factors were the same for boys and girls, in different age groups in 1992–3 and in 2002–3.</p><p>Results</p><p>The infant mortality rate declined from 148/1000 person years (PYRS) in 1992–3 to 124/1000 PYRS in 2002–3 (HR = 0.88;95%CI:0.77–0.99); this decline was significant for girls (0.77;0.64–0.94) but not for boys (0.97;0.82–1.15) (p = 0.10 for interaction). Risk factors did not differ significantly by cohort in either distribution or effect. Mortality decline was most marked among girls aged 9–11 months (0.56;0.37–0.83). There was no significant mortality decline for girls 1.5–8 months of age (0.93;0.68–1.28) (p = 0.05 for interaction). DTP and measles coverage increased from 1992–3 to 2002–3.</p><p>Conclusions</p><p>Risk factors did not change with the decline in mortality. Due to beneficial non-specific effects for girls, the increased coverage of measles vaccination may have contributed to the disproportional decline in mortality by sex and age group.</p></div

Crude infant mortality rates in the 1992–3 and 2002–3 birth cohorts for all children and by age groups—Overall and by sex.

<p>Crude infant mortality rates in the 1992–3 and 2002–3 birth cohorts for all children and by age groups—Overall and by sex.</p

Relative risk (RR) of DTP, MV and DTP, MV-only or other/no vaccines as most recent vaccination by 9, 10 and 11 months of age by cohort.

<p>Relative risk (RR) of DTP, MV and DTP, MV-only or other/no vaccines as most recent vaccination by 9, 10 and 11 months of age by cohort.</p

Distribution (frequencies) and association of potential risk factors with infant mortality in the 1992–3 and 2002–3 birth cohorts (univariate and multivariate analyses).

<p>Distribution (frequencies) and association of potential risk factors with infant mortality in the 1992–3 and 2002–3 birth cohorts (univariate and multivariate analyses).</p

Mortality (Hazard ratios (95%CI)) 6 months after seeing a vaccination card between 12 and 23 months according to having MV, DTP, DTP> = MV or other or no vaccine as most recent vaccination; overall and by sex^a.

<p>Mortality (Hazard ratios (95%CI)) 6 months after seeing a vaccination card between 12 and 23 months according to having MV, DTP, DTP> = MV or other or no vaccine as most recent vaccination; overall and by sex<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0177984#t004fn001" target="_blank">^a</a>.</p

Marsden et al 2011 Anopheles gambiae Molecular Ecology

Marsden et al 2011 Anopheles gambiae Molecular Ecolog

Association between recent antibiotic treatment and pneumococcal colonization and density.

<p>Association between recent antibiotic treatment and pneumococcal colonization and density.</p

Flowchart of MVPneumo.

<p>Flowchart of MVPneumo.</p

Comparison of baseline characteristics of the two randomization groups.

<p>Comparison of baseline characteristics of the two randomization groups.</p

Association between early measles vaccine (MV) and subsequent antibiotic treatment.

<p>Association between early measles vaccine (MV) and subsequent antibiotic treatment.</p