Rift Valley Fever (RVF)

Why in news?

In early November 2025, the World Health Organization (WHO) confirmed an outbreak of Rift Valley Fever (RVF) affecting Mauritania and Senegal in Western Africa.

• RVF – It is a mosquito-borne viral zoonotic disease that primarily affects livestock but can also infect humans.
• Caused by – Phlebovirus (Phenuiviridae family).
• 1^st Identified – In early 1930’s in Kenya’s Rift Valley during investigations into unexplained livestock deaths.
• Geographic Distribution – Endemic to sub-Saharan Africa, especially East and West Africa.
• In 2000, it crossed the Red Sea into Saudi Arabia and Yemen, marking its 1^st confirmed outbreak outside Africa.
• Affected population –
  • Primarily affect – Animals such as sheep, goats, cattle, and camels.
  • Humans – Infected through close contact with infected animals or by the bite of infected mosquitoes (No evidence of human-to-human transmission).
• Incubation period – Ranges from 2 to 6 days after exposure to the virus.
• Transmission –
  • For animals, transmitted mainly through mosquito bites.
  • Humans - Via contact with blood, fluids, or tissues of infected animals, or through mosquito bites.
  • No human-to-human transmission has been documented.
• Symptoms –
  • In Animals - High mortality in young livestock (sheep, goats, cattle, camels) and abortions in pregnant animals.
  • In Humans - Most cases are mild having fever, muscle pain, and headache, the severe cases (~1–2%) have hemorrhagic fever, encephalitis, or vision loss.
• Diagnosis – Requires laboratory testing — molecular (RT-PCR) or serological (ELISA) methods, under high biosafety precautions.
• Treatment – No specific antiviral treatment exists; management relies only on supportive care, including maintaining hydration, monitoring for organ failure, and preventing complications related to bleeding
• Vaccination – Available for animals and are effective between outbreaks, whereas, it is no licensed vaccine is available for humans.
• Prevention & Control – Adopt a One Health framework that links human, animal, and environmental health - animal surveillance, movement restrictions, vector control, animal vaccination & public health measures.
• Global Health Concern –
  • Listed by WHO as a priority pathogen with epidemic potential.
  • Recognized by the World Health Organization for Animal Health (WOAH) as a notifiable disease due to its cross-border spread risk.

India has not recorded any RVF cases in humans or animals to date, classified as an exotic zoonosis of concern under India’s One Health framework.

Reference

The Hindu | Rift Valley fever (RVF)