Rabies

Abstract

The inevitably fatal outcome of rabies makes it one of the most well-known and feared zoonoses. But rabies is still a neglected zoonotic disease (NZD), despite being one of the oldest diseases known. Dog-mediated rabies is the main cause of human rabies and is globally responsible for approximately 59,000 human deaths per year, nearly all occurring in low- and middle-income countries (LMICs). Most African countries and connected regions are high-risk areas for contracting rabies. Highly effective vaccines and post-exposure prophylaxis (PEP) for humans allow for the disease to be 100% preventable. But PEP is often unavailable or too expensive for affected people in LMICs. Recently, several new and low-tech diagnostic solutions have been developed, which offer opportunities to establish rabies diagnosis in remote areas and decentralise rabies laboratories.

Rabies has gained more global attention in recent years with development of new tools, formation of regional networks and implementation of a realistic global drive to eliminate canine-mediated human rabies by 2030. Canine rabies elimination is biologically feasible due to efficacious, safe and cheap vaccines and the low basic reproductive ratio (R ₀) of the disease. It is well known that mass dog vaccination is a cost-effective, sustainable measure to eliminate the disease at its source. Domestic dogs are tied to human populations, so the role of humans in rabies spread needs to be further investigated, for example through anthropogenic landscape features like roads or vaccine corridors, human movements and sociocultural factors. Combining powerful approaches, such as landscape epidemiology and genetics, can facilitate strategic control programmes and, for example, enable appropriate placement of vaccine barriers and surveillance points. It is known that major landscape features, such as oceans, mountains and deserts, can act as natural barriers to disease spread. However, very little is known about barrier effects at smaller scales. Long-distance transport of infected dogs by humans poses a risk of rabies introduction in novel places. For successful rabies control, it is also important to guarantee access to pre- and post-exposure prophylaxis, to build capacity in disease diagnosis and to conduct educational campaigns. Well-functioning, continuous rabies surveillance systems are crucial to provide reliable data to increase political commitment, which is eminently important for successful, sustainable disease control. For elimination of rabies in Africa and the connected regions, a multidisciplinary, transdisciplinary and regionally well-coordinated approach, with sustained vaccination programmes to maintain sufficient vaccination coverage, across political boundaries is required. To foster reflection on strategic rabies elimination on the African continent, one scenario of a possible spatio-temporal dynamic of dog rabies elimination in West Africa is proposed. Dog rabies elimination might, for example, start in northwestern Mauritania. The approach should be highly coordinated between the involved countries to avoid cross-border transmission and return of disease in rabies-free zones. It is difficult to mobilise large sums initially, but development impact bonds (DIB) offer an alternative funding mechanism. The total cost is estimated at 800 million to one billion Euros for rabies elimination in sub-Saharan West Africa, including Chad and Cameroon.