Understanding the relationship between WASH and malnutrition: Analysis of anthropometric data of children attending WASH-supported schools in Ogun State, Nigeria.

BACKGROUND: There has been a growing interest in better understanding the association between water, sanitation, and hygiene (WASH) and malnutrition. AIM: We analysed anthropometric data of children attending WASH intervention schools and those from non-intervention schools in Ogun State, Nigeria. METHODS: A total of 353 children across six schools (three interventions and three non-interventions) participated in this study. WASH conditions were assessed using WHO standardized tools and anthropometric data of children were analysed in WHO AnthroPlus and R Software. RESULTS: The prevalence of stunting was 26.2% in the intervention group, and 29.4% in the control group (p = 0.045). Underweight was lower in the intervention group (3.9% vs. 10.1%) (p = 0.45). However, wasting was higher in the intervention group (32.3% vs. 8.2%) (p = 0.001). Of the variables included in our multivariate model (age, gender, and school category, i.e. intervention/control and class grade), only age was selected, and negatively associated with underweight, stunting and wasting (p = 0.000). CONCLUSION: Regardless of WASH programming status, nutritional outcomes were significantly influenced by age of the children. Children are more likely to have lower z-scores as they grow older.

High-resolution species assignment of Anopheles mosquitoes using k-mer distances on targeted sequences.

The ANOSPP amplicon panel is a genus-wide targeted sequencing panel to facilitate large-scale monitoring of Anopheles species diversity. Combining information from the 62 nuclear amplicons present in the ANOSPP panel allows for a more senstive and specific species assignment than single gene (e.g. COI) barcoding, which is desirable in the light of permeable species boundaries. Here, we present NNoVAE, a method using Nearest Neighbours (NN) and Variational Autoencoders (VAE), which we apply to k-mers resulting from the ANOSPP amplicon sequences in order to hierarchically assign species identity. The NN step assigns a sample to a species-group by comparing the k-mers arising from each haplotype's amplicon sequence to a reference database. The VAE step is required to distinguish between closely related species, and also has sufficient resolution to reveal population structure within species. In tests on independent samples with over 80% amplicon coverage, NNoVAE correctly classifies to species level 98% of samples within the An. gambiae complex and 89% of samples outside the complex. We apply NNoVAE to over two thousand new samples from Burkina Faso and Gabon, identifying unexpected species in Gabon. NNoVAE presents an approach that may be of value to other targeted sequencing panels, and is a method that will be used to survey Anopheles species diversity and Plasmodium transmission patterns through space and time on a large scale, with plans to analyse half a million mosquitoes in the next five years.

Impacts of ivermectin mass drug administration for onchocerciasis on mosquito populations of Ogun state, Nigeria.

BACKGROUND: The impact of single-dose mass drug administration (MDA) of ivermectin for onchocerciasis on mosquito populations was investigated in Ogun State, Nigeria. METHODS: Indoor and outdoor collection of mosquitoes was carried out in two intervention (IC) and two control communities (CC) at three different periods: pre-MDA (baseline), 2-3 days after MDA and 13-14 days after MDA. The density and parity rate of female Anopheles and Culex mosquitoes were determined and compared. Environmental and climatic data of study locations were obtained to perform generalized linear model analysis. RESULTS: A total of 1399 female mosquitoes were collected, including 1227 Anopheles and 172 Culex mosquitoes. There was a similar magnitude of reduction in the indoor density of Anopheles by 29% in the IC and CC 2-3 days post-MDA but the reduction in indoor parity rate was significantly higher (p = 0.021) in the IC, reducing by more than 50%. In the IC, observation of a significant reduction at 2-3 days post-MDA was consistent for both the indoor density (1.43 to 1.02) and indoor parity rate (95.35% to 44.26%) of Anopheles mosquitoes. The indoor parity rate of Anopheles remained significantly reduced (75.86%) 13-14 post-MDA. On the other hand, the indoor density of Culex increased from 0.07 to 0.10 at 2-3 days post-MDA while the indoor parity rate of Culex did not change. The outdoor density of Anopheles in the IC increased (p = 0.394) from 0.58 to 0.90 at 2-3 days post-MDA; a similar observation was consistent for the outdoor density (2.83 to 3.90) and outdoor parity rate (70.59% to 97.44%) of Culex, while the outdoor parity rate of Anopheles reduced from 85.71 to 66.67% at 2-3 days post-MDA. A generalized linear model showed that ivermectin MDA significantly caused a reduction in both the indoor density (p < 0.001) and indoor parity rate (p = 0.003) of Anopheles in the IC. CONCLUSION: Ivermectin MDA resulted in the reduction of both the survival and density of Anopheles mosquitoes. This has strong implications for malaria transmission, which depends strongly on vector survival.

Schisto and Ladders version 2: a health educational board game to support compliance with school-based mass drug administration with praziquantel - a pilot study.

BACKGROUND: We redesigned the Schisto and Ladders health educational board game and evaluated its potential to encourage compliance to school-based mass drug administration with praziquantel. METHODS: Two hundred and seventy-five children from six schools who rejected praziquantel treatment were divided into intervention and control groups. Before the intervention, preassessment interviews were conducted on their knowledge about praziquantel treatment and schistosomiasis. The Schisto and Ladders version 2 game as an intervention, and the Snakes and Ladders game as a control, were played for 6 mo. Postassessment interviews, including focus group discussions, were conducted. RESULTS: At preassessment, 0/98 (0.0%) children in the intervention group had heard of praziquantel compared with 2/177 (1.1%) in the control group. Similarly, 0/98 (0.0%) children in the intervention group did not know that praziquantel does not kill compared with 4/177 (2.3%) in the control group. The postassessment showed that 53/78 (67.9%) in the intervention group were aware of praziquantel compared with 2/177 (1.1%) in the control group (p=0.000). Similarly, 53 (69.7%) in the intervention group knew about the safety of praziquantel compared with 0/177 (0.0%) in the control group (p=0.000). Sixty-four children (65.3%) from the intervention group sought praziquantel treatment after the trial. CONCLUSIONS: Schisto and Ladders version 2 is a useful sensitisation tool with which to encourage compliance to praziquantel treatment in schools.

Distribution of ascariasis, trichuriasis and hookworm infections in Ogun State, Southwestern Nigeria.

BACKGROUND: Ascariasis, Trichuriasis and Hookworm infections poses a considerable public health burden in Sub-Saharan Africa, and a sound understanding of their spatial distribution facilitates to better target control interventions. This study, therefore, assessed the prevalence of the trio, and mapped their spatial distribution in the 20 administrative regions of Ogun State, Nigeria. METHODS: Parasitological surveys were carried out in 1,499 households across 33 spatially selected communities. Fresh stool samples were collected from 1,027 consenting participants and processed using ether concentration method. The locations of the communities were georeferenced using a GPS device while demographic data were obtained using a standardized form. Data were analysed using SPSS software and visualizations and plotting maps were made in ArcGIS software. RESULTS: Findings showed that 19 of the 20 regions were endemic for one or more kind of the three infections, with an aggregated prevalence of 17.2%. Ascariasis was the most frequently observed parasitic infection in 28 communities with a prevalence of 13.6%, followed by hookworm infections with a prevalence of 4.6% while Trichuriasis was the least encountered with a prevalence of 1.7%. The spatial distribution of infections ranges between 5.3-49.2% across the regions. The highest and lowest distribution of overall helminth infections was recorded in Egbado South and Egbado North respectively. Nine regions had infection status between 20.0%-49.2%, while 10 regions had infection status between 5.3%-15.8%. CONCLUSION: This study provides epidemiological data on the prevalence and spatial distribution of ascariasis, trichuriasis and hookworm infections which will add to the baseline data and guide the public health officers in providing appropriate control strategies in the endemic communities.