Omega 3 and omega 6 fatty acids in human and animal health: an African perspective.

Lipids are essential for plant and animal development, growth and nutrition and play critical roles in health and reproduction. The dramatic increase in the human population has put increasing pressure on human food sources, especially of those sources of food which contain adequate levels of polyunsaturated fatty acids (PUFAs) and more importantly, sources of food which have favorable ratios of the n-3 (18-carbon, α-linolenic acid, ALA) to n-6 (18-carbon linoleic acid, LA) PUFAs. Recent studies have demonstrated the beneficial effects of the n-3 PUFAs in diets as well as potentially negative effects of excessive levels of n-6 PUFAs in diets. This review discusses these human health issues relating to changes in diets based on environmental and industrial changes as well as strategies in East Africa for improving lipid composition of food using indigenous sources.

Diagnosis of sexually transmitted infections and bacterial vaginosis among HIV-1-infected pregnant women in Nairobi.

HIV-infected women with sexually transmitted infections (STIs) or bacterial vaginosis (BV) during pregnancy are at increased risk for poor obstetric outcomes. In resource-limited settings, diagnostic testing for STIs and BV is often not available and most pregnant women are managed using syndromic algorithms. As part of a Nairobi perinatal cohort, HIV-1-infected pregnant women were interviewed and samples were collected for STIs and BV testing. Diagnostic accuracy of STIs and BV by syndromic algorithms was evaluated with comparison to the reference standard. Among 441 women, prevalence of BV was 37%, trichomoniasis 16%, chlamydia 4%, syphilis 3% and gonorrhoea 2%. Significantly more women with STIs were aged 21-years-old, had not attended secondary school and had a history of STIs. Syndromic diagnosis of STIs and BV demonstrated a sensitivity of 45% and 57%, and positive predictive value of 30% and 42%, respectively. Among these HIV-infected, pregnant women, STIs and vaginal infections were common and syndromic diagnosis was insensitive, resulting in missed opportunities to intervene and improve infant and maternal health.

Infant CD4 C868T polymorphism is associated with increased human immunodeficiency virus (HIV-1) acquisition.

The C868T single nucleotide polymorphism (SNP) in the CD4 receptor encodes an amino acid change that could alter its structure and influence human immunodeficiency virus (HIV-1) infection risk. HIV-1-infected pregnant women in Nairobi were followed with their infants for 1 year postpartum. Among 131 infants, those with the 868T allele were more likely than wild-type infants to acquire HIV-1 overall [hazard ratio (HR) = 1.92, 95% confidence interval (CI) 1.05, 3.50, P = 0.03; adjusted HR = 2.03, 95% CI 1.03, 3.98, P = 0.04], after adjusting for maternal viral load. This SNP (an allele frequency of approximately 15% in our cohort) was associated with increased susceptibility to mother-to-child HIV-1 transmission, consistent with a previous study on this polymorphism among Nairobi sex workers.

Salivary human immunodeficiency virus (HIV)-1-specific immunoglobulin A in HIV-1-exposed infants in Kenya.

Humoral immunity, and specifically immunoglobulin A (IgA) that is directed against human immunodeficiency virus (HIV)-1, may contribute to protection against HIV-1 acquisition at mucosal surfaces. HIV-1-specific IgA has been detected in genital tract secretions of HIV-1-uninfected commercial sex workers with HIV-1 exposure, and may be produced in parotid saliva by infants exposed orally to HIV-1 during delivery and breastfeeding. To explore this hypothesis, we collected saliva from 145 infants aged < or = 6 months enrolled in a perinatal HIV-1 transmission study in Nairobi and from 55 control infants without HIV-1 exposure who were born to HIV-1-seronegative mothers. Among the 145 infants, 115 (79%) remained uninfected during the 12-month study period and 30 (21%) became HIV-1-infected during follow-up. Nine (8%) of the 115 HIV-1-exposed, uninfected infants had detectable levels of HIV-1 gp160-specific IgA compared with four (13%) of 30 infected infants and none of 55 control infants (P = 0.47 and P = 0.03 respectively). Among the nine HIV-1-exposed, uninfected infants with positive assays, median age was 1 month and none acquired HIV-1 during follow-up. We conclude that HIV-1-specific salivary IgA responses may be generated by very young infants exposed perinatally to maternal HIV-1. Mucosal responses would be an appropriate target for paediatric vaccines against breast milk HIV-1 transmission.

Predictors of mortality in HIV-1 exposed uninfected post-neonatal infants at the Kenyatta National Hospital, Nairobi.

OBJECTIVES: To identify potential predictors of mortality, to determine mortality rate and to identify prevalent causes of death in a cohort of HIV-1 exposed uninfected infants. DESIGN: Prospective cohort study. SETTING: Kenyatta National Hospital, Nairobi, Kenya. SUBJECTS: Three hundred and fifty one HIV-1 exposed uninfected post-neonatal infants who survived to one year of age. RESULTS: Sixteen infants died (post-neonatal mortality rate of 47/1000 live births), 14 (88%) before six months of age. The most frequently identified medical conditions at death included bronchopneumonia, diarrhoea and failure to thrive. In multivariate analysis, prematurity (RR=10.5, 95%CI 3.8-29.1, p<0.001), teenage motherhood (RR=3.6, Cl 1.0-13.2, p=0.05) and symptomatic maternal HIV-1 disease (RR=2.7, CI 0.9-7.7, p=0.06) were associated with infant mortality. CONCLUSION: Prematurity, teenage motherhood and symptomatic HIV-1 maternal disease were important predictors for post-neonatal mortality in this cohort of HIV-1 exposed uninfected infants. These factors should be considered in monitoring and follow up in prevention of mother-to-child HIV-1 transmission (PMTCT) programs.