Analysis of rabies surveillance in selected African localities and prospects for continent-wide improvements

Abstract

Despite being a vaccine-preventable disease, rabies remains a significant public health concern throughout the developing world in particular, including all the countries of mainland Africa, where the disease results in the deaths of more than 25,000 people annually. Through a systematic review of rabies in African countries, a situational analysis highlighted the multifaceted challenges that contribute to the persistence of rabies and the current strategies employed by countries towards rabies elimination. Based on this, six critical barriers to rabies elimination could be identified: high domestic dog populations, inadequate surveillance and reporting, limited access to post-exposure prophylaxis (PEP) and vaccines, economic constraints, cultural factors, and low public awareness. This further highlighted the persistent nature of rabies across most African nations, emphasising the need for effective dog population management strategies and mass dog vaccination campaigns to break the cycle of rabies transmission. Furthermore, inadequate surveillance systems and reporting mechanisms result in a severe underreporting of rabies cases in both humans and animals, leading to an underestimation of the true burden of rabies. As such, national surveillance frameworks need to be implemented and should incorporate multidisciplinary partners and collaborative efforts between neighbouring countries. In an effort to supplement limited surveillance data by predicting gaps in the data, spatio-temporal analyses and data analyses were done using 21 years of laboratory-derived surveillance data from South Africa. The detailed spatio-temporal analysis presented here showed significant disease outbreaks in the eastern half of the country, where the highest human and dog populations could be found. Notably, the study identified underreported districts with limited surveillance, suggesting that enhanced monitoring could reveal larger disease clusters and enable targeted interventions. The analysis also captured the interplay between domestic and wildlife rabies, emphasising the need for integrated control measures. This case study based on South Africa provided evidence of the value of this approach to demonstrate the underestimation of the burden of rabies in the face of poor surveillance data – which is reality for all of Africa. Therefore, replication of this approach in other African countries and regions could add much value to the demonstration of disease burden and the direction of intervention strategies. Finally, considering the de facto challenges of rabies surveillance, a novel rapid diagnostic protocol was designed and evaluated for its potential to provide substantial improvements to the routine diagnosis and surveillance of the disease. In this protocol, the techniques for brain sampling were much simplified and lateral flow devices (LFDs) were implemented in a study that spanned over 28 months on the Unguja island of Zanzibar. Since the LFDs were implemented, a significant increase in the samples collected and sent for diagnostic testing could be seen. This work not only highlighted that LFD devices were highly specific and sensitive in diagnostically screening rabies cases but also showed that their implementation boosted the surveillance network on the island, leading to a more active surveillance approach. This, coupled with real-time reporting, enabled a meaningful increase in both active and passive surveillance across the island of Zanzibar, facilitating rapid outbreak responses, such as targeted and strategic vaccinations to rapidly break transmission cycles before rabies can spread and affect more animals and people. This further highlights the importance of novel techniques to improve overall surveillance.