Plasmodium falciparum malaria parasitaemia among indigenous Batwa and non‑indigenous communities of Kanungu district, Uganda

The indigenous Batwa of southwestern Uganda are among the most highly impoverished populations in Uganda, yet there is negligible research on the prevalence of malaria in this population. Plasmodium falciparum malaria parasitaemia prevalence was estimated in an indigenous Batwa and a non-indigenous neighbouring population, and an exploration of modifiable risk factors was carried out to identify potential entry points for intervention. Additionally, evidence of zooprophylaxis was assessed, hypothesizing that livestock ownership may play a role in malaria risk

A Longitudinal Analysis of Mosquito Net Ownership and Use in an Indigenous Batwa Population after a Targeted Distribution

Major efforts for malaria prevention programs have gone into scaling up ownership and use of insecticidal mosquito nets, particularly in sub-Saharan Africa where the malaria burden is high. Socioeconomic inequities in access to long lasting insecticidal nets (LLINs) are reduced with free distributions of nets. However, the relationship between social factors and retention of nets after a free distribution has been less studied, particularly using a longitudinal approach. Our research aimed to estimate the ownership and use of LLINs, and examine the determinants of LLIN retention, within an Indigenous Batwa population after a free LLIN distribution. Two LLINs were given free of charge to each Batwa household in Kanungu District, Uganda in November 2012. Surveyors collected data on LLIN ownership and use through six cross-sectional surveys pre- and post-distribution. Household retention, within household access, and individual use of LLINs were assessed over an 18-month period. Socioeconomic determinants of household retention of LLINs post-distribution were modelled longitudinally using logistic regression with random effects. Direct house-to-house distribution of free LLINs did not result in sustainable increases in the ownership and use of LLINs. Three months post-distribution, only 73% of households owned at least one LLIN and this period also saw the greatest reduction in ownership compared to other study periods. Eighteen-months post distribution, only a third of households still owned a LLIN. Self-reported age-specific use of LLINs was generally higher for children under five, declined for children aged 6–12, and was highest for older adults aged over 35. In the model, household wealth was a significant predictor of LLIN retention, controlling for time and other variables. This research highlights on-going socioeconomic inequities in access to malaria prevention measures among the Batwa in southwestern Uganda, even after free distribution of LLINs, and provides critical information to inform local malaria programs on possible intervention entry-points to increase access and use among this marginalized population

Best-fit model predicting household-level long lasting insecticidal net (LLIN) retention after a targeted distribution, controlling for repeated observations on households and community-level clustering among 10 Indigenous Batwa communities in Uganda.

<p>Best-fit model predicting household-level long lasting insecticidal net (LLIN) retention after a targeted distribution, controlling for repeated observations on households and community-level clustering among 10 Indigenous Batwa communities in Uganda.</p

Proportion of Batwa by age group in net use and non-use categories 3- and 18-months post-distribution in 10 Batwa communities, Kanungu district, southwestern Uganda.

<p>Denominators include all Batwa in each age group within the study sample. <i>LLIN use category</i>: sleeping under an LLIN (black). <i>LLIN non-use categories</i>: living in households hanging but not sleeping under an LLIN (dark grey); living in households owning but not hanging an LLIN (light grey); living in household not owning an LLIN (white) [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0154808#pone.0154808.ref020" target="_blank">20</a>].</p

Proportion of Batwa households by wealth tertile reporting ownership of a LLIN post-distribution and the equity ratio in ownership between the poorest and least poor households in 10 Batwa communities in Kanungu, over a year and a half period.

<p>The Y-axis for the equity ratio is inverted with increasing inequity towards a value of zero (top) and decreasing inequity (equity) towards a value of one (bottom). The equity ratio was calculated with the poorest households as the numerator and the least poor households as the denominator.</p

Household ownership, access, and use of LLINs 3 to 18-months post distribution among 10 Batwa communities (January 2013-April 2014).

<p>Household ownership, access, and use of LLINs 3 to 18-months post distribution among 10 Batwa communities (January 2013-April 2014).</p

Proportion of households that reported owning at least one net pre and post-distribution in 10 Batwa communities in southwestern Uganda.

<p>Households owning at least one mosquito net of any kind was calculated for December 2011 and those owning at least one LLIN was calculated for the post-distribution estimates. Post-distribution estimates include LLINs obtained outside of the IHACC LLIN distribution, though acquisition of nets from other sources was minimal.</p

Demographics and perceptions of malaria in 10 Batwa communities in Kanungu District, southwestern Uganda taken at the “mid-point” (January 2013), three months after LLIN distribution^*.

<p>Demographics and perceptions of malaria in 10 Batwa communities in Kanungu District, southwestern Uganda taken at the “mid-point” (January 2013), three months after LLIN distribution^{<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0154808#t001fn001" target="_blank">*</a>}.</p