Preventing Rift Valley Fever: The Urgent Need for a One Health Approach in Uganda

The study underscores the need for a One Health approach in Uganda to prevent Rift Valley fever outbreaks by improving zoonotic disease surveillance, enhancing cross-sector collaboration, and implementing early response measures. It highlights the gaps in current systems that allow livestock infections to precede human cases.

A comprehensive study by researchers from the Uganda Public Health Fellowship Program, Uganda National Institute of Public Health, the US Centers for Disease Control and Prevention, and the Ministry of Agriculture, Animal Industry and Fisheries, discusses the importance of a One Health approach in preventing human Rift Valley fever (RVF) infections in Uganda. This collaborative perspective underscores the necessity of integrating human, animal, and environmental health sectors to effectively manage and prevent zoonotic diseases, with a particular focus on RVF, a viral zoonosis that has caused sporadic outbreaks in Uganda. In May 2021, a 19-year-old woman from Kasaana Village in Kiruhura District, Western Uganda, was diagnosed with RVF, marking the beginning of a small outbreak in the area. Five additional cases were identified in the same village, all with a history of direct contact with livestock. This outbreak serves as a case study to highlight the recurring pattern of RVF in Uganda, where livestock infections typically precede human cases.

Investigating the Outbreak

The investigation into the outbreak involved interviews with local farmers and a review of veterinary records at the regional animal diagnostic laboratory. The researchers aimed to determine whether there were signs of RVF in livestock before the human cases were reported. The study found that among 162 livestock (94 cattle and 68 goats) from four farms reporting one or more abortions between March and June 2021, 57 animals were randomly selected for testing. Serological testing revealed that eight of these animals (three cattle and five goats) were IgM-seropositive for the RVF virus, indicating current infections. The presence of these antibodies suggests that the livestock were infected with RVF before the human cases were detected, likely due to contact with infected animal products or mosquitoes.

Gaps in Zoonotic Disease Surveillance

The findings of the study point to a significant gap in Uganda's zoonotic disease surveillance system. Despite the occurrence of livestock abortions and neonatal mortality, which are common indicators of RVF, these events were not reported or investigated in a timely manner. This delay allowed the virus to spread from animals to humans, demonstrating the need for a more proactive approach to zoonotic disease management. The researchers argue that early detection and response to infections in animals are crucial to preventing spillover to humans. However, the current surveillance system in Uganda is reactive rather than proactive, often detecting zoonotic outbreaks through human health surveillance before they are identified in animals.

Challenges in Operationalizing the One Health Approach

The article highlights the challenges in operationalizing the One Health approach in Uganda. Although the country has established a National One Health platform and developed a strategic plan for responding to zoonotic diseases, there has been little progress in implementing these initiatives beyond meetings and discussions. The researchers identify several barriers to effective One Health implementation, including a lack of collaboration and communication among sectors, the absence of a mechanism for sharing information across sectors, and insufficient funding for One Health activities. As a result, responses to zoonotic outbreaks in Uganda are often siloed, with human and animal health sectors working independently despite having the same goals.

Strengthening Surveillance and Collaboration

To address these challenges, the researchers call for strengthening the existing passive animal disease surveillance system and enhancing collaboration between the veterinary and public health sectors. They suggest that better-trained and equipped teams could conduct more effective surveillance, investigate livestock abortions, and collect specimens for diagnosis. Additionally, they advocate for regular testing of livestock in high-risk areas, vaccination of livestock to prevent disease spread, and mosquito control measures to reduce the risk of RVF transmission. The authors also emphasize the importance of formal information-sharing mechanisms among various agencies at the national and subnational levels. Such mechanisms would enable timely responses to zoonotic disease outbreaks and ensure that all relevant sectors are working together to mitigate the risks of disease spread.

The confirmation of RVF infections in livestock before human cases were reported in the same area highlights the need for a more integrated and proactive approach to zoonotic disease surveillance in Uganda. The study underscores the importance of the One Health approach, which promotes collaboration and information sharing across sectors to prevent and control zoonotic diseases. By strengthening surveillance systems, improving communication and collaboration between sectors, and implementing preventative measures such as vaccination and mosquito control, Uganda can better manage the risks associated with RVF and other zoonotic diseases. The researchers' findings provide valuable insights into the current gaps in Uganda's zoonotic disease management and offer recommendations for improving the country's response to future outbreaks.