Objectives: Yellow fever (YF) remains a public health threat in Sub-Saharan Africa and South America, with an estimated 200,000 cases and 30,000 deaths annually. Although the World Health Organization considers Tanzania to be at low risk for YF because no YF cases have been reported, the country remains at alert to importation of the virus due to ecological factors and high connectivity to high-risk YF areas in other countries. This study aimed to identify points of interest with connectivity to high-risk YF areas to guide preparedness efforts in Tanzania. Methods: Using the Population Connectivity Across Borders (PopCAB) toolkit, the Nelson Mandela African Institution of Science and Technology (Department of Health and Biomedical Sciences), in collaboration with the Tanzania Ministry of Health and the Centers for Disease Control and Prevention, implemented 12 focus group discussions with participatory mapping in two high-risk borders of Mutukula and Namanga. Results: Participants identified 147 and 90 points of interest with connectivity to YF risk areas in Kenya and Uganda, respectively. The identified locations are important for trade, fishing, pastoralism, tourism, health-seeking, agriculture, mining, religious activities, education, and cross-border marriages. Conclusions: The Tanzania Ministry of Health used the results to update cross-border surveillance and risk communication strategies and vaccination guidelines to prevent the importation of YF into Tanzania. © 2024 The Authors

INTRODUCTION: In March 2023, a Marburg Virus Disease (MVD) outbreak was declared in Kagera region, Northwestern Tanzania. This was the first MVD outbreak in the country. We describe the epidemiological characteristics of MVD cases and contacts. METHODS: The Ministry of Health activated an outbreak response team. Outbreak investigation methods were applied to cases identified through MVD standard case definitions and confirmed through reverse-transcriptase polymerase chain reaction (RT PCR). All identified case contacts were added into the contact listing form and followed up in-person daily for any signs or symptoms for 21 days. Data collected from various forms was managed and analyzed using Excel and QGIS software for mapping. RESULTS: A total of nine MVD cases were reported with eight laboratory-confirmed and one probable. Two of the reported cases were frontline healthcare workers and seven were family related members. Cases were children and adults between 1-59 years of age with a median age of 34 years. Six were males. Six cases died equivalent to a case fatality rate (CFR) of 66.7%. A total of 212 individuals were identified as contacts and two (2) became cases. The outbreak was localized in two geo-administrative wards (Maruku and Kanyangereko) of Bukoba District Council. CONCLUSION: Transmission during this outbreak occurred among family members and healthcare workers who provided care to the cases. The delay in detection aggravated the spread and possibly the consequent fatality but once confirmed the swift response stemmed further transmission containing the disease at the epicenter wards. The outbreak lasted for 72 days but as the origin is still unknown, further research is required to explore the source of this outbreak.

In 2016, Tanzania expanded sentinel surveillance for influenza-like illness (ILI) and severe acute respiratory infection (SARI) to include testing for non-influenza respiratory viruses (NIRVs) and additional respiratory pathogens at 9 sentinel sites. During 2017-2019, respiratory specimens from 2730 cases underwent expanded testing: 2475 specimens (90.7%) were tested using a U.S. Centers for Disease Control and Prevention (CDC)-developed assay covering 7 NIRVs (respiratory syncytial virus [RSV], rhinovirus, adenovirus, human metapneumovirus, parainfluenza virus 1, 2, and 3) and influenza A and B viruses. Additionally, 255 specimens (9.3%) were tested using the Fast-Track Diagnostics Respiratory Pathogens 33 (FTD-33) kit which covered the mentioned viruses and additional viral, bacterial, and fungal pathogens. Influenza viruses were identified in 7.5% of all specimens; however, use of the CDC assay and FTD-33 kit increased the number of specimens with a pathogen identified to 61.8% and 91.5%, respectively. Among the 9 common viruses between the CDC assay and FTD-33 kit, the most identified pathogens were RSV (22.9%), rhinovirus (21.8%), and adenovirus (14.0%); multi-pathogen co-detections were common. Odds of hospitalization (SARI vs. ILI) varied by sex, age, geographic zone, year of diagnosis, and pathogen identified; hospitalized illnesses were most common among children under the age of 5 years. The greatest number of specimens were submitted for testing during December-April, coinciding with rainy seasons in Tanzania, and several viral pathogens demonstrated seasonal variation (RSV, human metapneumovirus, influenza A and B, and parainfluenza viruses). This study demonstrates that expanding an existing influenza platform to include additional respiratory pathogens can provide valuable insight into the etiology, incidence, severity, and geographic/temporal patterns of respiratory illness. Continued respiratory surveillance in Tanzania, and globally, can provide valuable data, particularly in the context of emerging respiratory pathogens such as SARS-CoV-2, and guide public health interventions to reduce the burden of respiratory illnesses.

Tanzania reported its first COVID-19 case on 16 March 2020. We conducted event-based surveillance of COVID-19 suspect cases among pharmacy clients presenting with respiratory symptoms and influenza-like illness to increase early and rapid detection of COVID-19 cases and mitigate transmission. We conveniently sampled 103 pharmacies from Dar es Salaam, the epicentre for the COVID-19 pandemic in Tanzania at the time. Between 23 April 2020 and 18 May 2020, 67% of the pharmacies (69/103) reported an observed increase in the number of clients presenting with respiratory symptoms and influenza-like illness compared with the 1 month before the COVID-19 outbreak. In the 1-month surveillance period, the participating pharmacies recorded 75 alerts of COVID-19 suspect cases and referred all suspected COVID-19 cases to rapid response teams for additional symptomatic screening and SARS-CoV-2 testing. A key implementation challenge was that some clients identified as COVID-19 suspected cases were hesitant to provide follow-up information for linkage to rapid response teams. Addressing concerns among drug dispensers in the participating pharmacies and informing them of the benefits of the surveillance activity were important implementation components. Our approach demonstrates the overall feasibility of rapidly implementing an event-based surveillance system for an emerging health threat through an existing network of pharmacies within the community. The approach and tools used in this surveillance activity could be adapted in similar settings to detect and generate alerts of disease outbreaks in the community that other surveillance systems may otherwise miss.

BACKGROUND: Data on causes of respiratory deaths in Africa are limited. METHODS: From January to April 2013, 28 African countries were invited to participate in a review of severe acute respiratory illness (SARI) deaths identified from influenza surveillance during 2009 - 2012. RESULTS: Twenty-three (82%) countries responded, 11 (48%) collect mortality data, and 8 provided data. Data were collected from 37,714 SARI cases and 3091 (8.2%, range by country 5.1-25.9%) tested positive for influenza. There were 1073 (2.8%, range by country 0.1-5.3%) deaths reported among whom 57 (5.3%) were influenza-positive. Case fatality proportion (CFP) was higher among countries with systematic death reporting than those with sporadic reporting. The influenza-associated CFP was 1.8% (57/3091) compared to 2.9% (1016/34,623) for influenza-negative cases (p<0.001). Among 834 (77.7%) deaths tested for other respiratory pathogens, rhinovirus (n=107, 12.8%), adenovirus (n=64, 6.0%), respiratory syncytial virus (n=60, 5.6%), and S. pneumoniae (n=57, 5.3%) were most commonly identified. Among 1073 deaths, 402 (37.5%) were aged 0-4 years, 462 (43.1%) aged 5-49 years, and 209 (19.5%) aged 50 years and older. CONCLUSIONS: Few African countries systematically collect data on respiratory hospitalization outcomes. Stronger surveillance for respiratory deaths may identify risk groups for targeted vaccine use and other prevention strategies.