Browsing by Author "Openy, Geoffrey"

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    Apparent density, trypanosome infection rates and host preference of tsetse flies in the sleeping sickness endemic focus of northwestern Uganda
    (BMC Veterinary Research, 2021) Opiro, Robert; Opoke, Robert; Angwech, Harriet; Nakafu, Esther; Oloya, Francis A.; Openy, Geoffrey; Njahira, Moses; Macharia, Mercy; Echodu, Richard; Malinga, Geoffrey M.
    African trypanosomiasis, caused by protozoa of the genus Trypanosoma and transmitted by the tsetse fly, is a serious parasitic disease of humans and animals. Reliable data on the vector distribution, feeding preference and the trypanosome species they carry is pertinent to planning sustainable control strategies. Methodology: We deployed 109 biconical traps in 10 villages in two districts of northwestern Uganda to obtain information on the apparent density, trypanosome infection status and blood meal sources of tsetse flies. A subset (272) of the collected samples was analyzed for detection of trypanosomes species and sub-species using a nested PCR protocol based on primers amplifying the Internal Transcribed Spacer (ITS) region of ribosomal DNA. 34 blood-engorged adult tsetse midguts were analyzed for blood meal sources by sequencing of the mitochondrial cytochrome c oxidase 1 (COI) and cytochrome b (cytb) genes. Results: We captured a total of 622 Glossina fuscipes fuscipes tsetse flies (269 males and 353 females) in the two districts with apparent density (AD) ranging from 0.6 to 3.7 flies/trap/day (FTD). 10.7% (29/272) of the flies were infected with one or more trypanosome species. Infection rate was not significantly associated with district of origin (Generalized linear model (GLM), χ2 = 0.018, P = 0.895, df = 1, n = 272) and sex of the fly (χ2 = 1.723, P = 0.189, df = 1, n = 272). However, trypanosome infection was highly significantly associated with the fly’s age based on wing fray category (χ2 = 22.374, P < 0.001, df = 1, n = 272), being higher among the very old than the young tsetse. Nested PCR revealed several species of trypanosomes: T. vivax (6.62%), T. congolense (2.57%), T. brucei and T. simiae each at 0.73%. Blood meal analyses revealed five principal vertebrate hosts, namely, cattle (Bos taurus), humans (Homo sapiens), Nile monitor lizard (Varanus niloticus), African mud turtle (Pelusios chapini) and the African Savanna elephant (Loxodonta africana). Conclusion: We found an infection rate of 10.8% in the tsetse sampled, with all infections attributed to trypanosome species that are causative agents for AAT. However, more verification of this finding using large-scale passive and active screening of human and tsetse samples should be done. Cattle and humans appear to be the most important tsetse hosts in the region and should be considered in the design of control interventions.
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    Over a Century Evidence of Historical and Recent Dryness/ Wetness in Sub-Humid Areas: A Uganda, East African Case
    (Meteorological Applications, 2021) Byakatonda, Jimmy; Openy, Geoffrey; Sempewo, Jotham Ivan; Mucunguzi, Dominic Banaga
    Many regions globally are grappling with the challenge of recurrent extreme weather events. Whereas attempts are being undertaken to understand their characteristics as a first step to guide targeted mitigation measures, these are focused on dryness and not wetness, which is also a challenge in sub-humid areas. This study investigates dryness and wetness characteristics using the standardized precipitation evaporation index (SPEI) at timescales of 3, 6, 12 and 24 months for a period of 1901–2018 across Uganda's drainage basins. Trends in the dryness and wetness evolutions were conducted using the Mann-Kendall (MK) statistic to establish the effects of global warming on the study area. A step change analysis reveals 1961 as a change point year from cool to warm periods. Results also reveal that warming mainly occurred in the recent period (1962–2018), with a temperature rise of over 2οC being recorded in 2009. Severe dryness events occurred in the recent period as opposed to wetness events that dominated the earlier period (1901–1961). Dryness and wetness varied among drainage basins, with the Aswa basin being more susceptible to severe dryness while the Lake Kyoga basin to severe wetness. Lira and Kitgum were identified as drought hotspots at timescales of 3, 6 and 12 months. SPEI was able to reveal 60% of historical dryness events and 75% of wetness events on record, making it an adequate tool for monitoring humid events as opposed to droughts in sub-humid climates. It is hoped that this evidence can guide targeted mitigation measures towards climatic shocks within the region.
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    Prevalence of diarrhoea and associated risk factors among children under five years old in Pader District, northern Uganda
    (BMC Infectious Diseases, 2020) Omona, Stephen; Malinga, Geoffrey M.; Opoke, Robert; Openy, Geoffrey; Opiro, Robert
    Diarrhoea remains a major cause of morbidity and mortality in children under 5 years in sub-Saharan Africa. Of the three East African countries, Uganda has the worst mortality rate in children < 5 years, with 22% of these deaths attributed to diarrhoea. For proper planning and implementation of control, an understanding of the prevalence and determinants of the disease is crucial. This study assessed the prevalence of diarrhoea and related risk factors among children < 5 years in Pajule Subcounty, Pader District in northern Uganda. Methods: A cross-sectional survey was conducted in April 2018, covering 244 randomly selected households having children < 5 years old in the study area. A semi-structured questionnaire was used to interview the households about diarrhoeal history in their children in the last 2 weeks preceding the survey, and on the risk factors predisposing children to diarrhoeal infections. Bivariate and multivariate logistic regression analyses with a 95% confidence interval and p < 0.05 was used to identify the risk factors associated with childhood diarrhoeal disease. Results: We found a prevalence of diarrhoea of 29.1% [95% CI (23.7–35.0)] among children < 5 years in Pajule Subcounty during the 2 weeks preceding the survey. Use of unprotected water sources, age of child caretaker, child weaning time and family size had significant associations with diarrhoeal morbidity. Conclusion: The prevalence of childhood diarrhoea among children < 5 years of age in rural settings of Pajule Subcounty was higher than the Ugandan national average. Use of unprotected water sources, age of child caretaker, child weaning time and family size were identified as predictors of diarrhoeal occurrence. These findings underscore the need for improving access to clean water and providing community health education as the best methods for fighting childhood diarrhoea in the study area.