Dimorphism in genes encoding sexual-stage proteins of Plasmodium ovale curtisi and Plasmodium ovale wallikeri.

Plasmodium ovale curtisi and Plasmodium ovale wallikeri are distinct species of malaria parasite which are sympatric throughout the tropics, except for the Americas. Despite this complete overlap in geographic range, these two species do not recombine. Although morphologically very similar, the two taxa must possess distinct characters which prevent recombination between them. We hypothesised that proteins required for sexual reproduction have sufficiently diverged between the two species to prevent recombination in any mosquito blood meal in which gametocytes of both species are ingested. In order to investigate possible barriers to inter-species mating between P. ovale curtisi and P. ovale wallikeri, homologues of genes encoding sexual stage proteins in other plasmodia were identified and compared between the two species. Database searches with motifs for 6-cysteine, Limulus Coagulation factor C domain-containing proteins and other relevant sexual stage proteins in the genus Plasmodium were performed in the available P. ovale curtisi partial genome database (Wellcome Trust Sanger Institute, UK). Sequence fragments obtained were used as the basis for PCR walking along each gene of interest in reference isolates of both P. ovale curtisi and P. ovale wallikeri. Sequence alignment of the homologues of each gene in each species showed complete dimorphism across all isolates. In conclusion, substantial divergence between sexual stage proteins in the two P. ovale spp. was observed, providing further evidence that these do not recombine in nature. Incompatibility of proteins involved in sexual development and fertilisation thus remains a plausible explanation for the observed lack of natural recombination between P. ovale curtisi and P. ovale wallikeri

Determinants of malnutrition among under-fives in Bengo province, Angola

Introduction - Nutrition is capable of maximize health and minimize morbidity and mortality in early childhood. In fact, some nutritional disturbances, if not detected nor treated in the first 1000 days of a child0s life, can have irreversible consequences impairing an individual for his entire life. New interventions to reduce undernutrition should be designed taking into account their determinants. This study aims to identify factors associated with undernutrition (wasting, stunting and underweight) among children under 5 years in Bengo province, Angola. Materials and Methods - Logistic regression analysis was used to examine undernutrition against a set of variables associated with health, water and parental caregiver factors. Children nutritional status was classified as underweight, stunted and wasted if their Z-scores for weight-for-age (WAZ), heightfor- age (HAZ) and weight-for-height (WHZ) were less than 2.0 SD of the WHO (2006) standards. Results - The present study comprised 803 children, of whom 50.8% were males and 43% aged 0–23 months. Concerning to parental practices, 36% of the under-twos were currently breastfeeding, and 89% were breastfeed for more than 12 months. 84% started complementary feedin within <6 months of birth. The caregivers reported that 34% of the children had diarrhea in the last 2 weeks and 53.4% of the mothers did not treat drinking water. The prevalence of wasting was 5.6%, of stunting 30.7% and of underweight 29.0%. The most significant factors for wasting were age of the child (OR 4.5, 2.1–9.3 risk for 0–23 age), being breastfed (OR 4.0, 2.0–7.7) and diarrhea episodes (OR 2.0, 1.0–3.7). The most significant factors for stunting were mother0s education (OR 0.5, 0.2–0.9 for mother with secondary or higher education), age of the child (OR 0.5, 0.4–0.8 risk for 0–23 age), being breastfed (OR 0.4, 0.3–0.6). The most significant factors for underweight were age of the child (OR 1.7, 1.1–2.6 risk for 0–23 age class), being breastfed (OR 1.7, 1.1–2.7) and diarrhea episodes (OR 1.9, 1.3–3.1). Conclusions The study suggests the necessity of different approaches in interventions depending on the age group. Community-based education interventions are needed to reduce preventable morbidity and mortality triggered by undernutrition.info:eu-repo/semantics/publishedVersio

Observed and predicted prevalence of <i>Hymenolepis nana</i> infection (A) and predicted prevalence of <i>S. haematobium</i> (B) in the Dande municipality in Angola.

<p>Observed and predicted prevalence of <i>Hymenolepis nana</i> infection (A) and predicted prevalence of <i>S. haematobium</i> (B) in the Dande municipality in Angola.</p

Extending Helminth Control beyond STH and Schistosomiasis: The Case of Human Hymenolepiasis

<p>Extending Helminth Control beyond STH and Schistosomiasis: The Case of Human Hymenolepiasis</p