Recent overnight travel and the risk of malaria: case-control and prospective cohort studies in Uganda

Introduction: Travel is an underappreciated risk factor for malaria in residents of malaria-endemic countries. In Uganda, malaria transmission is heterogeneous, in part due to expansion of malaria control interventions and increased urbanization. As a result, individuals who travel may be at higher risk of malaria infection. However, our understanding of the association between travel and malaria infection in Uganda is limited. Methods: This thesis aimed to address this evidence gap through: 1) case-control study in urban Kampala, 2) cohort study in three sites of varied malaria transmission, and 3) cohort study in rural Tororo, which is under intense malaria control with indoor residual spraying (IRS). For the case control study, 5 controls were selected for every 2 cases, matching on age. Data were collected in July and August 2019 on recent overnight travel out of Kampala (past 60 days), destination and duration of travel, and behavioural factors, including sleeping under a long-lasting insecticidal net (LLIN) during travel. For the cohort study at three sites in Uganda (PRISM 1), information on overnight travel was collected between 2015 and 2016 from children aged 0.5-10 years and one adult living in 266 randomly selected households. Malaria, defined as fever with parasites detected by microscopy, was measured using passive surveillance. For the cohort in rural Tororo (PRISM 2), data on overnight travel and behaviour during travel were collected from residents of 80 households between 2017 and 2019. Behaviour while at home was assessed using a similar questionnaire during two-weekly home visits. Results: In the case-control study, 162 cases and 405 controls were enrolled. Overall, 158 (27.9%) participants reported recent overnight travel. Travellers were far more likely to be diagnosed with malaria than those who did not travel (80.4% vs 8.6%, odds ratio 58.9, 95% 4 confidence interval [CI] 23.1-150.1, p 15 years (33.9% travel vs 61.3% home, RR 0.55, 95% CI 0.41-0.74, p<0.001). Conclusions: Residents of malaria endemic countries who travel are a high-risk group that should be targeted for malaria prevention. For these travellers, personal protection measures, including sleeping under LLINs when traveling, application of creams or sprays to prevent outdoor mosquito bites, and administration of chemoprophylaxis, should be advocated

Drivers of Tracking Administration of Malaria Drugs in Health Units in Uganda. A Descriptive and Correlational Study.

Background: This study aimed at examining malaria intrinsic factors and technology controls as drivers of tracking administration malaria drugs focusing on the roles of both health workers and health units.  Methodology: Descriptive and correlational research designs were employed upon 465 health workers from 564 health units in the central districts of Uganda for which purposive and randomization techniques were used.   Results:  8.5% of health workers don’t test blood in hospitals, HC III and clinics majorly private facilities that have existed between 5-9 years, nurses noticeably base on just own experience to examination malaria patients. 11.8% don’t use slides to examine blood, health units that have existed as below as five years fall suit. Difficulty in electronic data exchange (26.7%), lack freedom to use electronic systems to access information on malaria drugs (41.9%), poor networks connectivity (60.0%) and poor response time (50.5%) are prominent. Perceptions, attitudes, knowledge, and skills of use of ICTs affect tracking administration of malaria drugs.  Conclusion: Parasites’ identification, quantification, and speciation concerns decrease from hospitals, clinics, HC III to IV in public health units that existed for 15 and below 5 years. Junior nurses with certificates and diplomas with work experience of 1-5 years mostly in general, pediatrics and “others” departments manage malaria issues with minimum guidance and supervision. Engagement of Rapid Diagnostic Test kits is higher in hospitals, clinics, pharmacies, HC III, and IV.  Recommendations: MoH should improve on planning, surveillance, and supervision of health facilities across to enforce diagnosis for malaria cases management and reduction drug resistance. Regulate a holistic and non-discriminative policy on diagnosis, treatment (drugs), and control of malaria and emphasized balanced, effective, and sustainable results. Gargets, training to handle malaria cases regardless of whether the facility is public or privately be prioritized for good tracking administration of malaria drugs

Expression of a rice chitinase gene in transgenic banana (''Gros Michel'', AAA genome group) confers resistance to black leaf streak disease

Transgenic banana (Musa acuminata 'Gros Michel') integrating either of two rice chitinase genes was generated and its resistance to Black Leaf Streak disease caused by the fungus Mycosphaerella fijiensis was tested using a leaf disk bioassay. PCR screening indicated the presence of the hpt selectable marker gene in more than 90 % of the lines tested, whereas more than three quarters of the lines contained the linked rice chitinase gene resulting in a co-transformation frequency of at least 71.4 %. Further, a unique stable integration of the transgenes in each line revealed some false negative PCR results and the expected co-transformation frequency of 100 %

Measuring socioeconomic inequalities in relation to malaria risk: a comparison of metrics in rural Uganda

ocioeconomic position (SEP) is an important risk factor for malaria, but there is no consensus on how to measure SEP in malaria studies. We evaluated the relative strength of four indicators of SEP in predicting malaria risk in Nagongera, Uganda. 318 children resident in 100 households were followed for 36 months to measure parasite prevalence routinely every three months and malaria incidence by passive case detection. Household SEP was determined using: (1) two wealth indices, (2) income, (3) occupation and (4) education. Wealth Index I (reference) included only asset ownership variables. Wealth Index II additionally included food security and house construction variables, which may directly affect malaria. In multivariate analysis, only Wealth Index II and income were associated with the human biting rate, only Wealth Indices I and II were associated with parasite prevalence and only caregiver’s education was associated with malaria incidence. This is the first evaluation of metrics beyond wealth and consumption indices for measuring the association between SEP and malaria. The wealth index still predicted malaria risk after excluding variables directly associated with malaria, but the strength of association was lower. In this setting, wealth indices, income and education were stronger predictors of socioeconomic differences in malaria risk than occupation

Intestinal schistosomiasis in Uganda at high altitude (>1400 m): malacological and epidemiological surveys on Mount Elgon and in Fort Portal crater lakes reveal extra preventive chemotherapy needs

Background Intestinal schistosomiasis is of public health importance in Uganda but communities living above 1400 m are not targeted for control as natural transmission is thought unlikely. To assess altitudinal boundaries and at-risk populations, conjoint malacological and epidemiological surveys were undertaken on Mount Elgon (1139 m–3937 m), in Fort Portal crater lakes and in the Rwenzori Mountains (1123 m–4050 m). Methods Seventy freshwater habitats [Mount Elgon (37), Fort Portal crater lakes (23), Rwenzori Mountains (8) and Lake Albert (2)] were inspected for Biomphalaria species. Water temperature, pH and conductivity were recorded. A parasitological examination of 756 schoolchildren [Mount Elgon (300), Fort Portal crater lakes (456)] by faecal microscopy of duplicate Kato-Katz smears from two consecutive stool samples was bolstered by antigen (urine-CCA dipstick) and antibody (SEA-ELISA) diagnostic assays. Results Biomphalaria spp. was found up to 1951 m on Mount Elgon and 1567 m in the Fort Portal crater lakes. Although no snail from Mount Elgon shed cercariae, molecular analysis judged 7.1% of snails sampled at altitudes above 1400 m as having DNA of Schistosoma mansoni; in Fort Portal crater lakes three snails shed schistosome cercariae. Prevalence of intestinal schistosomiasis as measured in schoolchildren by Kato-Katz (Mount Elgon = 5.3% v. Fort Portal crater lakes = 10.7%), CCA urine-dipsticks (18.3% v. 34.4%) and SEA-ELISA (42.3% v. 63.7%) showed negative associations with increasing altitude with some evidence of infection up to 2000 m. Conclusions Contrary to expectations, these surveys clearly show that natural transmission of intestinal schistosomiasis occurs above 1400 m, possibly extending up to 2000 m. Using spatial epidemiological predictions, this now places some extra six million people at-risk, denoting an expansion of preventive chemotherapy needs in Uganda

Why is malaria associated with poverty? Findings from a cohort study in rural Uganda

Background Malaria control and sustainable development are linked, but implementation of ‘multisectoral’ intervention is restricted by a limited understanding of the causal pathways between poverty and malaria. We investigated the relationships between socioeconomic position (SEP), potential determinants of SEP, and malaria in Nagongera, rural Uganda. Methods Socioeconomic information was collected for 318 children aged six months to 10 years living in 100 households, who were followed for up to 36 months. Mosquito density was recorded using monthly light trap collections. Parasite prevalence was measured routinely every three months and malaria incidence determined by passive case detection. First, we evaluated the association between success in smallholder agriculture (the primary livelihood source) and SEP. Second, we explored socioeconomic risk factors for human biting rate (HBR), parasite prevalence and incidence of clinical malaria, and spatial clustering of socioeconomic variables. Third, we investigated the role of selected factors in mediating the association between SEP and malaria. Results Relative agricultural success was associated with higher SEP. In turn, high SEP was associated with lower HBR (highest versus lowest wealth index tertile: Incidence Rate Ratio 0.71, 95 % confidence intervals (CI) 0.54–0.93, P = 0.01) and lower odds of malaria infection in children (highest versus lowest wealth index tertile: adjusted Odds Ratio 0.52, 95 % CI 0.35–0.78, P = 0.001), but SEP was not associated with clinical malaria incidence. Mediation analysis suggested that part of the total effect of SEP on malaria infection risk was explained by house type (24.9 %, 95 % CI 15.8–58.6 %) and food security (18.6 %, 95 % CI 11.6–48.3 %); however, the assumptions of the mediation analysis may not have been fully met. Conclusion Housing improvements and agricultural development interventions to reduce poverty merit further investigation as multisectoral interventions against malaria. Further interdisplinary research is needed to understand fully the complex pathways between poverty and malaria and to develop strategies for sustainable malaria control

Estimating malaria parasite prevalence from community surveys in Uganda: a comparison of microscopy, rapid diagnostic tests and polymerase chain reaction.

BACKGROUND: Household surveys are important tools for monitoring the malaria disease burden and measuring impact of malaria control interventions with parasite prevalence as the primary metric. However, estimates of parasite prevalence are dependent on a number of factors including the method used to detect parasites, age of the population sampled, and level of immunity. To better understand the influence of diagnostics, age, and endemicity on estimates of parasite prevalence and how these change over time, community-based surveys were performed for two consecutive years in three settings and the sensitivities of microscopy and immunochromatographic rapid diagnostic tests (RDTs) were assessed, considering polymerase chain reaction (PCR) as the gold standard. METHODS: Surveys were conducted over the same two-month period in 2012 and 2013 in each of three sub-counties in Uganda: Nagongera in Tororo District (January-February), Walukuba in Jinja District (March-April), and Kihihi in Kanungu District (May-June). In each sub-county, 200 households were randomly enrolled and a household questionnaire capturing information on demographics, use of malaria prevention methods, and proxy indicators of wealth was administered to the head of the household. Finger-prick blood samples were obtained for RDTs, measurement of hemoglobin, thick and thin blood smears, and to store samples on filter paper. RESULTS: A total of 1200 households were surveyed and 4433 participants were included in the analysis. Compared to PCR, the sensitivity of microscopy was low (65.3% in Nagongera, 49.6% in Walukuba and 40.9% in Kihihi) and decreased with increasing age. The specificity of microscopy was over 98% at all sites and did not vary with age or year. Relative differences in parasite prevalence across different age groups, study sites, and years were similar for microscopy and PCR. The sensitivity of RDTs was similar across the three sites (range 77.2-82.8%), was consistently higher than microscopy (p < 0.001 for all pairwise comparisons), and decreased with increasing age. The specificity of RDTs was lower than microscopy (76.3% in Nagongera, 86.3% in Walukuba, and 83.5% in Kihihi) and varied significantly by year and age. Relative differences in parasite prevalence across age groups and study years differed for RDTs compared to microscopy and PCR. CONCLUSION: Malaria prevalence estimates varied with diagnostic test, age, and transmission intensity. It is important to consider the effects of these parameters when designing and interpreting community-based surveys

An assessment of the readiness for introduction of the HPV vaccine in Uganda

Formative research assessing human papillomavirus (HPV) vaccine readiness in Uganda was conducted in 2007. The objective was to generate evidence for government decision-making and operationalplanning for HPV vaccine introduction. Qualitative research methods with children, parents, teachers, community leaders, health workers, technical experts and political leaders were used to captureunderstanding of socio-cultural, health system and policy environments. We found low levels of knowledge about cervical cancer and HPV. Vaccination and its benefits were well-understood;respondents were positive about HPV vaccination. Health systems were deemed adequate for HPV vaccine delivery. Schools were identifie as a vaccination venue, given high attendance by girls aged10-12 years. Communication and advocacy strategies to foster acceptance should provide information on cervical cancer, HPV vaccine safety, and side effects. Policymakers requested further detail on costs.Introduction of HPV vaccine could be integrated into existing reproductive health and immunization policies (Afr J Reprod Health 2008; 12[3]:159-172)

Associations between urbanicity and malaria at local scales in Uganda

Background: Sub-Saharan Africa is expected to show the greatest rates of urbanization over the next 50 years. Urbanization has shown a substantial impact in reducing malaria transmission due to multiple factors, including unfavourable habitats for Anopheles mosquitoes, generally healthier human populations, better access to healthcare, and higher housing standards. Statistical relationships have been explored at global and local scales, but generally only examining the effects of urbanization on single malaria metrics. In this study, associations between multiple measures of urbanization and a variety of malaria metrics were estimated at local scales. Methods: Cohorts of children and adults from 100 households across each of three contrasting sub-counties of Uganda (Walukuba, Nagongera and Kihihi) were followed for 24 months. Measures of urbanicity included density of surrounding households, vegetation index, satellite-derived night-time lights, land cover, and a composite urbanicity score. Malaria metrics included the household density of mosquitoes (number of female Anopheles mosquitoes captured), parasite prevalence and malaria incidence. Associations between measures of urbanicity and malaria metrics were made using negative binomial and logistic regression models. Results: One site (Walukuba) had significantly higher urbanicity measures compared to the two rural sites. In Walukuba, all individual measures of higher urbanicity were significantly associated with a lower household density of mosquitoes. The higher composite urbanicity score in Walukuba was also associated with a lower household density of mosquitoes (incidence rate ratio = 0.28, 95 % CI 0.17–0.48, p < 0.001) and a lower parasite prevalence (odds ratio, OR = 0.44, CI 0.20–0.97, p = 0.04). In one rural site (Kihihi), only a higher density of surrounding households was associated with a lower parasite prevalence (OR = 0.15, CI 0.07–0.34, p < 0.001). And, in only one rural site (Nagongera) was living where NDVI ≤0.45 associated with higher incidence of malaria (IRR = 1.35, CI 1.35–1.70, p = 0.01). Conclusions: Urbanicity has been shown previously to lead to a reduction in malaria transmission at large spatial scales. At finer scales, individual household measures of higher urbanicity were associated with lower mosquito densities and parasite prevalence only in the site that was generally characterized as being urban. The approaches outlined here can help better characterize urbanicity at the household level and improve targeting of control interventions