Evaluation of malaria outbreak detection methods, Uganda, 2022.

BACKGROUND: Malaria outbreaks are detected by applying the World Health Organization (WHO)-recommended thresholds (the less sensitive 75th percentile or mean + 2 standard deviations [2SD] for medium-to high-transmission areas, and the more sensitive cumulative sum [C-SUM] method for low and very low-transmission areas). During 2022, > 50% of districts in Uganda were in an epidemic mode according to the 75th percentile method used, resulting in a need to restrict national response to districts with the highest rates of complicated malaria. The three threshold approaches were evaluated to compare their outbreak-signaling outputs and help identify prioritization approaches and method appropriateness across Uganda. METHODS: The three methods were applied as well as adjusted approaches (85th percentile and C-SUM + 2SD) for all weeks in 2022 for 16 districts with good reporting rates ( ≥ 80%). Districts were selected from regions originally categorized as very low, low, medium, and high transmission; district thresholds were calculated based on 2017-2021 data and re-categorized them for this analysis. RESULTS: Using district-level data to categorize transmission levels resulted in re-categorization of 8/16 districts from their original transmission level categories. In all districts, more outbreak weeks were detected by the 75th percentile than the mean + 2SD method (p < 0.001). For all 9 very low or low-transmission districts, the number of outbreak weeks detected by C-SUM were similar to those detected by the 75th percentile. On adjustment of the 75th percentile method to the 85th percentile, there was no significant difference in the number of outbreak weeks detected for medium and low transmission districts. The number of outbreak weeks detected by C-SUM + 2SD was similar to those detected by the mean + 2SD method for all districts across all transmission intensities. CONCLUSION: District data may be more appropriate than regional data to categorize malaria transmission and choose epidemic threshold approaches. The 75th percentile method, meant for medium- to high-transmission areas, was as sensitive as C-SUM for low- and very low-transmission areas. For medium and high-transmission areas, more outbreak weeks were detected with the 75th percentile than the mean + 2SD method. Using the 75th percentile method for outbreak detection in all areas and the mean + 2SD for prioritization of medium- and high-transmission areas in response may be helpful.

Ownership and use of long-lasting insecticidal nets three months after a mass distribution campaign in Uganda, 2021.

BACKGROUND: Uganda conducted its third mass long-lasting insecticidal net (LLIN) distribution campaign in 2021. The target of the campaign was to ensure that 100% of households own at least one LLIN per two persons and to achieve 85% use of distributed LLINs. LLIN ownership, use and associated factors were assessed 3 months after the campaign. METHODS: A cross-sectional household survey was conducted in 14 districts from 13 to 30 April, 2021. Households were selected using multistage sampling. Each was asked about LLIN ownership, use, duration since received to the time of interview, and the presence of LLINs was visually verified. Outcomes were having at least one LLIN per two household members, and individual LLIN use. Modified Poisson regression was used to assess associations between exposures and outcomes. RESULTS: In total, 5529 households with 27,585 residents and 15,426 LLINs were included in the analysis. Overall, 95% of households owned ≥ 1 LLIN, 92% of the households owned ≥ 1 LLIN < 3 months old, 64% of households owned ≥ 1 LLIN per two persons in the household. Eighty-seven per cent could sleep under an LLIN if every LLIN in the household were used by two people, but only 69% slept under an LLIN the night before the survey. Factors associated with LLIN ownership included believing that LLINs are protective against malaria (aPR = 1.13; 95% CI 1.04-1.24). Reported use of mosquito repellents was negatively associated with ownership of LLINs (aPR = 0.96; 95% CI 0.95-0.98). The prevalence of LLIN use was 9% higher among persons who had LLINs 3-12 months old (aPR = 1.09; 95% CI 1.06-1.11) and 10% higher among those who had LLINs 13-24 months old (aPR = 1.10; 95% CI 1.06-1.14) than those who had LLINs < 3 months old. Of 3,859 LLINs identified in the households but not used for sleeping the previous night, 3250 (84%) were < 3 months old. Among these 3250, 41% were not used because owners were using old LLINs; 16% were not used because of lack of space for hanging them; 11% were not used because of fear of chemicals in the net; 5% were not used because of dislike of the smell of the nets; and, 27% were not used for other reasons. CONCLUSION: The substantial difference between the population that had access to LLINs and the population that slept under LLINs indicates that the National Malaria Control Programme (NMCP) may need to focus on addressing the main drivers or barriers to LLIN use. NMCP and/or other stakeholders could consider designing and conducting targeted behaviour change communication during subsequent mass distribution of LLINs after the mass distribution campaign to counter misconceptions about new LLINs.

Outbreak of cutaneous anthrax associated with handling meat of dead cows in Southwestern Uganda, May 2018.

BACKGROUND: Anthrax is a zoonotic infection caused by the bacteria Bacillus anthracis. Humans acquire cutaneous infection through contact with infected animals or animal products. On May 6, 2018, three cows suddenly died on a farm in Kiruhura District. Shortly afterwards, a sub-county chief in Kiruhura District received reports of humans with suspected cutaneous anthrax in the same district. The patients had reportedly participated in the butchery and consumption of meat from the dead cows. We investigated to determine the magnitude of the outbreak, identify exposures associated with illness, and suggest evidence-based control measures. METHODS: We conducted a retrospective cohort study among persons whose households received any of the cow meat. We defined a suspected human cutaneous anthrax case as new skin lesions (e.g., papule, vesicle, or eschar) in a resident of Kiruhura District from 1 to 26 May 2018. A confirmed case was a suspected case with a lesion testing positive for B. anthracis by polymerase chain reaction (PCR). We identified cases through medical record review at Engari Health Centre and active case finding in the community. RESULTS: Of the 95 persons in the cohort, 22 were case-patients (2 confirmed and 20 suspected, 0 fatal cases) and 73 were non-case household members. The epidemic curve indicated multiple point-source exposures starting on May 6, when the dead cows were butchered. Among households receiving cow meat, participating in slaughtering (RR = 5.3, 95% CI 3.2-8.3), skinning (RR = 4.7, 95% CI = 3.1-7.0), cleaning waste (RR = 4.5, 95% CI = 3.1-6.6), and carrying meat (RR = 3.9, 95% CI = 2.2-7.1) increased the risk of infection. CONCLUSIONS: This cutaneous anthrax outbreak was caused by handling infected animal carcasses. We suggested to the Ministry of Agriculture, Animal Industry and Fisheries to strengthen surveillance for possible veterinary anthrax and ensure that communities do not consume carcasses of livestock that died suddenly. We also suggested that the Ministry of Health equip health facilities with first-line antibiotics for community members during outbreaks.

Investigation of possible preventable causes of COVID-19 deaths in the Kampala Metropolitan Area, Uganda, 2020-2021.

BACKGROUND: Identifying preventable causes of COVID-19 deaths is key to reducing mortality. We investigated possible preventable causes of COVID-19 deaths over a six-month period in Uganda. METHODS: A case-patient was a person testing reverse transcription polymerase chain reaction-positive for SARS-CoV-2 who died in Kampala Metropolitan Area hospitals from August 2020 to February 2021. We reviewed records and interviewed health workers and case-patient caretakers. RESULTS: We investigated 126 (65%) of 195 reported COVID-19 deaths during the investigation period; 89 (71%) were male, and the median age was 61 years. A total of 98 (78%) had underlying medical conditions. Most (118, 94%) had advanced disease at admission to the hospital where they died. A total of 44 (35%) did not receive a COVID-19 test at their first presentation to a health facility despite having consistent symptoms. A total of 95 (75%) needed intensive care unit admission, of whom 45 (47%) received it; 74 (59%) needed mechanical ventilation, of whom 47 (64%) received it. CONCLUSION: Among hospitalized patients with COVID-19 who died in this investigation, early opportunities for diagnosis were frequently missed, and there was inadequate intensive care unit capacity. Emphasis is needed on COVID-19 as a differential diagnosis, early testing, and care-seeking at specialized facilities before the illness reaches a critical stage. Increased capacity for intensive care is needed.

A prolonged cholera outbreak caused by drinking contaminated stream water, Kyangwali refugee settlement, Hoima District, Western Uganda: 2018.

BACKGROUND: On 23 February 2018, the Uganda Ministry of Health (MOH) declared a cholera outbreak affecting more than 60 persons in Kyangwali Refugee Settlement, Hoima District, bordering the Democratic Republic of Congo (DRC). We investigated to determine the outbreak scope and risk factors for transmission, and recommend evidence-based control measures. METHODS: We defined a suspected case as sudden onset of watery diarrhoea in any person aged ≥ 2 years in Hoima District, 1 February-9 May 2018. A confirmed case was a suspected case with Vibrio cholerae cultured from a stool sample. We found cases by active community search and record reviews at Cholera Treatment Centres. We calculated case-fatality rates (CFR) and attack rates (AR) by sub-county and nationality. In a case-control study, we compared exposure factors among case- and control-households. We estimated the association between the exposures and outcome using Mantel-Haenszel method. We conducted an environmental assessment in the refugee settlement, including testing samples of stream water, tank water, and spring water for presence of fecal coliforms. We tested suspected cholera cases using cholera rapid diagnostic test (RDT) kits followed by culture for confirmation. RESULTS: We identified 2122 case-patients and 44 deaths (CFR = 2.1%). Case-patients originating from Demographic Republic of Congo were the most affected (AR = 15/1000). The overall attack rate in Hoima District was 3.2/1000, with Kyangwali sub-county being the most affected (AR = 13/1000). The outbreak lasted 4 months, which was a multiple point-source. Environmental assessment showed that a stream separating two villages in Kyangwali Refugee Settlement was a site of open defecation for refugees. Among three water sources tested, only stream water was feacally-contaminated, yielding > 100 CFU/100 ml. Of 130 stool samples tested, 124 (95%) yielded V. cholerae by culture. Stream water was most strongly associated with illness (odds ratio [OR] = 14.2, 95% CI: 1.5-133), although tank water also appeared to be independently associated with illness (OR = 11.6, 95% CI: 1.4-94). Persons who drank tank and stream water had a 17-fold higher odds of illness compared with persons who drank from other sources (OR = 17.3, 95% CI: 2.2-137). CONCLUSIONS: Our investigation demonstrated that this was a prolonged cholera outbreak that affected four sub-counties and two divisions in Hoima District, and was associated with drinking of contaminated stream water. In addition, tank water also appears to be unsafe. We recommended boiling drinking water, increasing latrine coverage, and provision of safe water by the District and entire High Commission for refugees.

Ebola Virus Disease Preparedness Assessment and Risk Mapping in Uganda, August-September 2018.

Uganda's proximity to the tenth Ebola virus disease (EVD) outbreak in the Democratic Republic of the Congo (DRC) presents a high risk of cross-border EVD transmission. Uganda conducted preparedness and risk-mapping activities to strengthen capacity to prevent EVD importation and spread from cross-border transmission. We adapted the World Health Organization (WHO) EVD Consolidated Preparedness Checklist to assess preparedness in 11 International Health Regulations domains at the district level, health facilities, and points of entry; the US Centers for Disease Control and Prevention (CDC) Border Health Capacity Discussion Guide to describe public health capacity; and the CDC Population Connectivity Across Borders tool kit to characterize movement and connectivity patterns. We identified 40 ground crossings (13 official, 27 unofficial), 80 health facilities, and more than 500 locations in 12 high-risk districts along the DRC border with increased connectivity to the EVD epicenter. The team also identified routes and congregation hubs, including origins and destinations for cross-border travelers to specified locations. Ten of the 12 districts scored less than 50% on the preparedness assessment. Using these results, Uganda developed a national EVD preparedness and response plan, including tailored interventions to enhance EVD surveillance, laboratory capacity, healthcare professional capacity, provision of supplies to priority locations, building treatment units in strategic locations, and enhancing EVD risk communication. We identified priority interventions to address risk of EVD importation and spread into Uganda. Lessons learned from this process will inform strategies to strengthen public health emergency systems in their response to public health events in similar settings.

Uganda's experience in Ebola virus disease outbreak preparedness, 2018-2019.

BACKGROUND: Since the declaration of the 10th Ebola Virus Disease (EVD) outbreak in DRC on 1st Aug 2018, several neighboring countries have been developing and implementing preparedness efforts to prevent EVD cross-border transmission to enable timely detection, investigation, and response in the event of a confirmed EVD outbreak in the country. We describe Uganda's experience in EVD preparedness. RESULTS: On 4 August 2018, the Uganda Ministry of Health (MoH) activated the Public Health Emergency Operations Centre (PHEOC) and the National Task Force (NTF) for public health emergencies to plan, guide, and coordinate EVD preparedness in the country. The NTF selected an Incident Management Team (IMT), constituting a National Rapid Response Team (NRRT) that supported activation of the District Task Forces (DTFs) and District Rapid Response Teams (DRRTs) that jointly assessed levels of preparedness in 30 designated high-risk districts representing category 1 (20 districts) and category 2 (10 districts). The MoH, with technical guidance from the World Health Organisation (WHO), led EVD preparedness activities and worked together with other ministries and partner organisations to enhance community-based surveillance systems, develop and disseminate risk communication messages, engage communities, reinforce EVD screening and infection prevention measures at Points of Entry (PoEs) and in high-risk health facilities, construct and equip EVD isolation and treatment units, and establish coordination and procurement mechanisms. CONCLUSION: As of 31 May 2019, there was no confirmed case of EVD as Uganda has continued to make significant and verifiable progress in EVD preparedness. There is a need to sustain these efforts, not only in EVD preparedness but also across the entire spectrum of a multi-hazard framework. These efforts strengthen country capacity and compel the country to avail resources for preparedness and management of incidents at the source while effectively cutting costs of using a "fire-fighting" approach during public health emergencies.

A four-year trend in pulmonary bacteriologically confirmed tuberculosis case detection in Kampala-Uganda.

BACKGROUND: The management and control of pulmonary bacteriologically confirmed (PBC) tuberculosis (TB) also known as infectious TB is important not only to monitor for resistance but also to check for severity, treatment response and limit its spread. METHOD: A retrospective analysis of diagnosis smear results of PBC TB patients in Kampala district registered between January 2012 and December 2015 at 65 TB diagnosis and treatment units (DTUs) was done. RESULTS: Of the 10,404 records; 6551 (63.0%) belonged to PBC TB patients, 3734 (57.0%) of whom were male. Sputum smear microscopy was the diagnostic test most commonly used 4905 (74.9%) followed by GeneXpert testing, 1023 (15.6%). Majority, 1951 (39.8%), of the PBC TB patients had a smear positivity grading of 3+ (> 10 acid-fast bacillus (AFB)/Fields). Public facilities diagnosed more PBC TB patients compared to private facilities, 3983 (60.8%) vs 2566 (39.2%). From 2012 through 2015, there was a statistically significant increase in PBC TB patients enrolled on anti-TB treatment from 1389 to 2194 (p = 0.000). The percentage of HIV positive co-infected PBC TB patients diagnosed decreased from 597(43%) to 890(40.6%) (p = 0.000) within same period. Linkage to HIV care improved from 229 (34.4%) in 2012 to 464 (52.1%) in 2015 (p = 0.000). The treatment success rate (TSR) for PBC TB patients improved from 69% in 2012 to 75.5% by end of 2015 (p = 0.001) with an improvement in cure rate from 52.3% to 62% (p = 0.000). There was an observed significant decrease in TB related mortality from 8.9 to 6.4% (p = 0.013). CONCLUSION: The proportion of diagnosed PBC TB patients increased from 2012 to 2015. PBC TB patients diagnosed with 3+ smear positivity grading results consistently contributed to the highest proportion of diagnosed PBC TB patients from 2012 to 2015. This could be due to the delay in diagnosis of TB patients because of late presentation of patients to clinics. A prospective study of PBC TB patients diagnosed with 3+ smear positivity grading may elucidate the reasons for the delay to diagnosis. Further, we propose a study of wider scope to estimate how many people a single PBC TB patient is likely to infect with TB before being diagnosed and treated.

Response to anti-tuberculosis treatment by people over age 60 in Kampala, Uganda.

While old age is a known risk factor for developing active tuberculosis (TB), studies on TB in the population aged 60 years and older (considered elderly in this study) are few, especially in the developing world. Results of the TB prevalence survey in Uganda found high TB prevalence (570/100,000) in people over 65. We focused on treatment outcomes in the elderly to understand this epidemic better. We conducted a retrospective analysis of data from TB facility registers in Kampala City for the period 2014-2015. We analyzed the 2014-15 cohort with respect to age, sex, disease class, patients' human immunodeficiency virus (HIV) and directly observed therapy (DOT) status, type of facility, and treatment outcomes and compared findings in the elderly (≥60) and younger (<60) age groups. Of 15,429 records, 3.3% (514/15,429) were for elderly patients. The treatment success rate (TSR) among elderly TB patients (68.3%) was lower than that of the non-elderly (80.9%) and the overall TSR 80.5%, (12,417/15,429) in Kampala. Although the elderly were less likely to test positive for HIV than the young (AOR 0.39; 95% CI 0.33-0.48, p<0.001), they had a two-fold higher risk of unfavorable treatment outcomes (AOR 2.14; CI 1.84-2.72, p<0.001) and were more likely to die while on treatment (AOR 1.86; CI 1.27-2.73; p = 0.001). However, there was no statistically significantly difference between treatment outcomes among HIV-positive and HIV-negative elderly TB patients. Compared to the younger TB patients, elderly TB patients have markedly poorer treatment outcomes, although TB/HIV co-infection rates in this age group are lower.