Evaluation of the sentinel yellow fever surveillance system in Uganda, 2017-2022: strengths and weaknesses.

BACKGROUND: Uganda has a sentinel surveillance system in seven high-risk sites to monitor yellow fever (YF) patterns and detect outbreaks. We evaluated the performance of this system from 2017 to 2022. METHODS: We evaluated selected attributes, including timeliness (lags between different critical time points), external completeness (proportion of expected sentinel sites reporting ≥ 1 suspect case in the system annually), and internal completeness (proportion of reports with the minimum required data elements filled), using secondary data in the YF surveillance database from January 2017-July 2022. We conducted key informant interviews with stakeholders at health facility and national level to assess usefulness, flexibility, simplicity, and acceptability of the surveillance system. RESULTS: In total, 3,073 suspected and 15 confirmed YF cases were reported. The median time lag from sample collection to laboratory shipment was 37 days (IQR:21-54). External completeness was 76%; internal completeness was 65%. Stakeholders felt that the surveillance system was simple and acceptable, but were uncertain about flexibility. Most (71%) YF cases in previous outbreaks were detected through the sentinel surveillance system; data were used to inform interventions such as intensified YF vaccination. CONCLUSION: The YF sentinel surveillance system was useful in detecting outbreaks and informing public health action. Delays in case confirmation and incomplete data compromised its overall effectiveness and efficiency.

Comprehensive knowledge of HIV prevention among fishing communities of Lake Kyoga, Uganda, 2013.

BACKGROUND: Compared to the general population in Uganda, fishing communities suffer greater burden of HIV/AIDS. We determined the level of comprehensive knowledge on HIV prevention and its associated factors among fishing communities of Lake Kyoga. METHODS: We conducted secondary analysis of data from the Lake Kyoga Behavioral Survey, a population-based sample survey on behavioral risk factors for HIV, syphilis, and schistosomiasis among adults in fishing communities of Lake Kyoga in 2013. We defined comprehensive knowledge as having correct knowledge on HIV prevention (consistent condom use, faithfulness, a healthy-looking person can have HIV, and HIV cannot be transmitted through food-sharing, witchcraft or handshake). We used logistic regression to determined potential factors associated with comprehensive knowledge on HIV prevention and control for confounding. RESULTS: Of 1780 persons in the sample, 51% (911/1780) were females. The mean age was 32 (range: 15-97) years. Overall, 51% (899/1780) of persons had comprehensive knowledge on HIV prevention. Level of comprehensive knowledge on HIV prevention was similar between females (52%, 449/911) and males (49%, 450/869). Males (76%, 658/869) had lower knowledge on HIV transmission from mother to child during breast feeding compared to females (81%, 738/911) (p-value 0.019). Fishermen (46%,324/711) who lived > 5 km away from a health center compared to 54% (572/1066) who lived within 5 km radius were less likely to have comprehensive knowledge on HIV prevention (PRRadj = 0.8; 95%CI = 0.5-0.92). Those who had ever tested for HIV were more likely to have comprehensive knowledge of HIV transmission (PRRadj = 1.1; 95% 1.03-1.70). CONCLUSION: Half of the population of Lake Kyoga fishing community had comprehensive knowledge of HIV prevention. Long distances from health facilities reduced the level of comprehensive knowledge on HIV transmission. HIV testing increased the level of comprehensive knowledge on HIV transmission. Ministry of health should ensure that HIV/AIDS information; education and communication and HIV counseling and testing activities are intensified in fishing communities of Lake Kyoga, with more emphasis on communities living in distances of more than 5 km away from the health facility.

A cholera outbreak caused by drinking contaminated river water, Bulambuli District, Eastern Uganda, March 2016.

BACKGROUND: A cholera outbreak started on 29 February in Bwikhonge Sub-county, Bulambuli District in Eastern Uganda. Local public health authorities implemented initial control measures. However, in late March, cases sharply increased in Bwikhonge Sub-county. We investigated the outbreak to determine its scope and mode of transmission, and to inform control measures. METHODS: We defined a suspected case as sudden onset of watery diarrhea from 1 March 2016 onwards in a resident of Bulambuli District. A confirmed case was a suspected case with positive stool culture for V. cholerae. We conducted descriptive epidemiologic analysis of the cases to inform the hypothesis on mode of transmission. To test the hypothesis, we conducted a case-control study involving 100 suspected case-patients and 100 asymptomatic controls, individually-matched by residence village and age. We collected seven water samples for laboratory testing. RESULTS: We identified 108 suspected cases (attack rate: 1.3%, 108/8404), including 7 confirmed cases. The case-control study revealed that 78% (78/100) of case-patients compared with 51% (51/100) of control-persons usually collected drinking water from the nearby Cheptui River (ORMH = 7.8, 95% CI = 2.7-22); conversely, 35% (35/100) of case-patients compared with 54% (54/100) of control-persons usually collected drinking water from borehole pumps (ORMH = 0.31, 95% CI = 0.13-0.65). The index case in Bwikhonge Sub-county had onset on 29 February but the outbreak had been on-going in the neighbouring sub-counties in the previous 3 months. V. cholera was isolated in 2 of the 7 river water samples collected from different locations. CONCLUSIONS: We concluded that this cholera outbreak was caused by drinking contaminated water from Cheptui River. We recommended boiling and/or treating drinking water, improved sanitation, distribution of chlorine tablets to the affected villages, and as a long-term solution, construction of more borehole pumps. After implementing preventive measures, the number of cases declined and completely stopped after 6th April.

Timeliness and completeness of monthly disease surveillance data reporting, Uganda, 2020-2021.

Introduction: timely and complete reporting of routine public health information about diseases and public health events are important aspects of a robust surveillance system. Although data on the completeness and timeliness of monthly surveillance data are collected in the District Health Information System-2 (DHIS2), they have not been routinely analyzed. We assessed completeness and timeliness of monthly outpatient department (OPD) data, January 2020-December 2021. Methods: we analyzed secondary data from all the 15 regions and 146 districts of Uganda. Completeness was defined as the number of submitted reports divided by the number of expected reports. Timeliness was defined as the number of reports submitted by the deadline (15th day of the following month) divided by reports received. Completeness or timeliness score of <80% was regarded incomplete or untimely. Results: overall, there was good general performance with the median completeness being high in 2020 (99.5%; IQR 97.8-100%) and 2021 (100%; IQR 98.7-100%), as was the median timeliness (2020; 82.8%, IQR 74.6-91.8%; 2021, 94.9%, IQR 86.5-99.1%). Kampala Region was the only region that consistently failed to reach ≥ 80% OPD timeliness (2020: 44%; 2021: 65%). Nakasongola was the only district that consistently performed poorly in the submission of timely reports in both years (2020: 54.4%, 2021: 58.3%). Conclusion: there was an overall good performance in the submission of complete and timely monthly OPD reports in most districts and regions in Uganda. There is a need to strengthen the good reporting practices exhibited and offer support to regions, districts, and health facilities with timeliness challenges.

Evaluation of public health surveillance systems in refugee settlements in Uganda, 2016-2019: lessons learned.

BACKGROUND: Civil wars in the Great Lakes region resulted in massive displacement of people to neighboring countries including Uganda. With associated disease epidemics related to this conflict, a disease surveillance system was established aiming for timely detection of diseases and rapid response to outbreaks. We describe the evaluation of and lessons learned from the public health surveillance system set up in refugee settlements in Uganda. METHODS: We conducted a cross-sectional survey using the US Centers for Disease Control and Prevention Updated Guidelines for Evaluating Public Health Surveillance Systems and the Uganda National Technical Guidelines for Integrated Disease Surveillance and Response in four refugee settlements in Uganda-Bidibidi, Adjumani, Kiryandongo and Rhino Camp. Using semi-structured questionnaires, key informant and focus group discussion guides, we interviewed 53 health facility leaders, 12 key personnel and 224 village health team members from 53 health facilities and 112 villages and assessed key surveillance functions and attributes. RESULTS: All health facilities assessed had key surveillance staff; 60% were trained on Integrated Disease Surveillance and Response and most village health teams were trained on disease surveillance. Case detection was at 55%; facilities lacked standard case definitions and were using parallel Implementing Partner driven reporting systems. Recording was at 79% and reporting was at 81%. Data analysis and interpretation was at 49%. Confirmation of outbreaks and events was at 76%. Preparedness was at 72%. Response was at 34%. Feedback was at 82%. Evaluate and improve the system was at 67%. There was low capacity for detection, response and data analysis and interpretation of cases (< 60%). CONCLUSION: The surveillance system in the refugee settlements was functional with many performing attributes but with many remaining gaps. There was low capacity for detection, response and data analysis and interpretation in all the refugee settlements. There is need for improvement to align surveillance systems in refugee settlements with the mainstream surveillance system in the country. Implementing Partners should be urged to offer support for surveillance and training of surveillance staff on Integrated Disease Surveillance and Response to maintain effective surveillance functions. Functionalization of district teams ensures achievement of surveillance functions and attributes. Regular supervision of and support to health facility surveillance personnel is essential. Harmonization of reporting improves surveillance functions and attributes and appropriation of funds by government to districts to support refugee settlements is complementary to maintain effective surveillance of priority diseases in the northern and central part of Uganda.

Investigation of a Cluster of Severe Respiratory Disease Referred from Uganda to Kenya, February 2017.

On February 22, 2017, Hospital X-Kampala and US CDC-Kenya reported to the Uganda Ministry of Health a respiratory illness in a 46-year-old expatriate of Company A. The patient, Mr. A, was evacuated from Uganda to Kenya and died. He had recently been exposed to dromedary camels (MERS-CoV) and wild birds with influenza A (H5N6). We investigated the cause of illness, transmission, and recommended control. We defined a suspected case of severe acute respiratory illness (SARI) as acute onset of fever (≥38°C) with sore throat or cough and at least one of the following: headache, lethargy, or difficulty in breathing. In addition, we looked at cases with onset between February 1 and March 31 in a person with a history of contact with Mr. A, his family, or other Company A employees. A confirmed case was defined as a suspected case with laboratory confirmation of the same pathogen detected in Mr. A. Influenza-like illness was defined as onset of fever (≥38°C) and cough or sore throat in a Uganda contact, and as fever (≥38°C) and cough lasting less than 10 days in a Kenya contact. We collected Mr. A's exposure and clinical history, searched for cases, and traced contacts. Specimens from the index case were tested for complete blood count, liver function tests, plasma chemistry, Influenza A(H1N1)pdm09, and MERS-CoV. Robust field epidemiology, laboratory capacity, and cross-border communication enabled investigation.

Variation in malaria transmission intensity in seven sites throughout Uganda.

Knowledge of the baseline malaria transmission in a given environment is important to guide malaria control interventions. However, in Uganda, recent information on malaria transmission intensity is lacking. Therefore, a 1-year entomological study was conducted in seven ecologically different sites throughout the country to assess spatial and temporal patterns in malaria transmission intensity. Anopheles gambiae sensu stricto was the main vector in five of the seven study sites, and An. funestus was the most important vector in the two other sites. In a peri-urban village, An. arabiensis contributed substantially to malaria transmission. Clear differences in annual entomological inoculation rates (AEIR) were observed between the study sites, ranging from 4 infective bites per person per year in the southwestern part of the country to >1,500 infective bites per person per year in a swampy area near the Nile River. Between villages with parasite prevalences of >or= 80% in children between 1 and 9 years old, a 4-fold difference in AEIR was observed. Based on the observed behavior of the vectors, insecticide-treated bed nets will be highly effective in controlling malaria. However, in the high transmission areas, additional measures will be needed to reduce the malaria burden to acceptable levels.

Spatio-temporal patterns in kdr frequency in permethrin and DDT resistant Anopheles gambiae s.s. from Uganda.

The planned upscaling of vector control strategies requires insight into the epidemiological consequences of vector resistance. Therefore, the pyrethroid and DDT resistance status of Anopheles gambiae s.l. was assessed in Uganda from 2004 to 2006, and spatial and seasonal variations in knockdown resistance (kdr) frequencies were analyzed in terms of epidemiological significance. Anopheles gambiae s.l. was DDT and pyrethroid resistant in central and eastern Uganda. The L1014S kdr allele frequencies varied from 3% to 48% in An. gambiae s.s. Although the homozygous resistant genotype was the most prevalent genotype among survivors, the genotypes could not entirely explain the bioassay results. In the dry season, the kdr frequency was significantly higher in Plasmodium falciparum-infected mosquitoes, indicating that mosquitoes bearing a kdr mutation have a better adult survival, hence a higher likelihood of becoming infectious. This study showed that kdr might have an epidemiological impact that could jeopardize the vector control strategies.