Rift Valley fever epidemiology: shifting the paradigm and rethinking research priorities

Area of Science:

• Veterinary Medicine
• Epidemiology
• Virology

Background:

• Rift Valley fever (RVF) is a zoonotic disease caused by the Rift Valley fever virus (RVFV).
• RVFV poses significant economic and public health challenges.
• Current understanding emphasizes flood-induced epidemics and interepidemic persistence in mosquito eggs.

Purpose of the Study:

• To challenge the classic framework of RVFV epidemiology.
• To propose a broader understanding of RVFV dynamics.
• To advocate for research into hyperendemic RVFV drivers.

Main Methods:

• This study presents a "Personal View" challenging existing epidemiological models.
• It synthesizes evidence to support a revised paradigm.
• It calls for further investigation into RVFV transmission.

Main Results:

• RVFV epidemiology encompasses a spectrum from epidemic to hyperendemic dynamics.
• RVFV is maintained in a variable reservoir system including livestock, wildlife, and mosquitoes.
• Transovarial transmission is not the sole mechanism of persistence.

Conclusions:

• The classic model of RVFV epidemiology is insufficient.
• A nuanced understanding of RVFV dynamics, including hyperendemicity, is necessary.
• Further research is crucial to elucidate drivers of RVFV dynamics in hyperendemic regions.