In a mixed-effects logistic regression, after adjusting for age, infection status, elevation, and clustering by cell, the Batwa had a 2-fold higher odds of being seropositive compared with the Bakiga (OR = 2.08, 95% CI = 1.512.88). twice those observed in the Bakiga. For the Batwa, multiple factors may Triacsin C be associated with higher exposure to malaria and antibody levels relative to their non-indigenous neighbors. Considerable heterogeneity in malaria transmission levels and disease burden can be found within and between populations in endemic areas, due to variations in local vector populations, socioeconomic factors, and individual susceptibility.1,2Understanding this variation is usually important to enable better deployment Triacsin C of interventions to reach the populations most at risk. Malaria transmission intensity is commonly measured using the entomological inoculation rate (EIR; the number of infectious bites per person per year) and/or parasite rate (the number of infected individuals per populace). However, in low-transmission settings, these metrics lack sensitivity due to low numbers of infected mosquitos and humans.3Serological techniques are increasingly used in the assessment of malaria transmission intensity and provide credible estimates of transmission that correlate well with EIR.4At an individual level, antibody responses can provide an Triacsin C alternative measure against which to assess risk of exposure to infection.5,6 This study presents the results of a seroepidemiological study investigating exposure to malaria in the indigenous Batwa and neighboring non-indigenous populations in Kanungu District, located in southwestern Uganda, bordering the Democratic Republic of Congo. The district is largely rural and is characterized by mesoendemic malaria transmission with intermittent epidemics of disease.7,8Rainfall is bimodal with peaks in April and October. The Batwa are traditional hunter-gatherers from Uganda, Burundi, Rwanda, and eastern Congo.9There are approximately 6,700 Batwa individuals residing in southwestern Uganda, comprising the easternmost population of central Africa’s pygmy population.10In 1992, the Batwa in Uganda were evicted from their traditional forest homelands due to the formation of Bwindi Impenetrable National Park.11The dominant non-indigenous ethnic group in the region, the Bakiga, are traditional agriculturalists, originally migrating from Rwanda to Uganda before the time of European colonization in the early 1900s and settling in the southwestern region of the country.12 Approval for this study was granted from the research ethics boards of McGill University or college (Ref: A11-M120-13B), the London School of Hygiene and Tropical Medicine (Ref: 7761), the Ottawa Hospital Research Network (Ref: 20150201-01H), and the University or college of Guelph (Ref: 14MR002). The study design is consistent with the Canadian Tri-Council’s guidelines and requirements of the Ethical Conduct of Research Involving Human Subjects. Informed consent was obtained verbally from all participants and village chairpersons. Community-based cross-sectional surveys were conducted as Triacsin C explained in detail elsewhere.13,14In April 2014, 136 indigenous Batwa households and 201 non-indigenous Bakiga households were surveyed in the 10 local councils (hereafter referred to as cells) in Kanungu District, comprising all of Kanungu’s 10 Batwa settlements and their neighboring Bakiga villages, resulting in a total of 543 and 731 individuals, respectively. The response rate was 94.9% and 99.4% among the Batwa and Bakiga, respectively. Ages ranged from < 1 to 96 years (mean = 20.4 years) among the Batwa and < 1 to 87 years (mean = 22.7 years) among the Bakiga. Populace samples were comparable in age and sex, even though Batwa population experienced slightly more men (44.9% versus 38.9%, 2= 4.26,P= 0.039) and was slightly younger (50.5% versus 46.8% under 15 years of age, 2= 13.1,P= 0.011) compared with the Bakiga. Ownership and usage of insecticide-treated bednets were lower among Batwa individuals (33.8% versus 47.2%, 2= 22.3,P< 0.001, and 21.3% versus 40.3%, 2= 52.5,P< 0.001, respectively). Rabbit polyclonal to AFF3 The majority of individuals in both populations lived in houses with iron sheet roofer: 88.8% among the Batwa and 90.0% among the Bakiga (P= 0.49). Malaria prevalence by CareStartmalaria quick diagnostic assessments (mRDTs) was 14.9% among the Batwa compared with 9.26% among the Bakiga (2= 33.0P< 0.001). In univariable regression analyses, age, ethnicity, bednet ownership, and household roof material were associated with mRDT positivity. These variables were included in a mixed-effects logistic regression along with two cell-level factors, elevation and normalized differential vegetation index (NDVI). In the final model, after controlling for age and cell-level clustering, there were no significant effects of sex, bednet ownership, roof material, or NDVI on mRDT positivity. However, a significant altitudeethnicity interaction effect was found. In population-specific models, higher elevation was significantly associated with lower odds of mRDT positivity among the Bakiga (odds ratio [OR] = 0.19, 95% confidence interval [CI] = 0.110.35,P< 0.001 at elevations 1,3011,500 m; OR = 0.11, 95% CI = 0.040.33,P< 0.001 at elevations > 1,500 m). In contrast, among the Batwa, the effect was less.
In a mixed-effects logistic regression, after adjusting for age, infection status, elevation, and clustering by cell, the Batwa had a 2-fold higher odds of being seropositive compared with the Bakiga (OR = 2