A dog being vaccinated against rabies

ILRI expertise on zoonotic diseases

Scientists estimate that 70% of emerging infectious diseases originate from animals, and 60% of the existing infectious disease are zoonotic. Zoonotic diseases are transmitted from animals to humans and can be spread through water, food, and the environment. COVID-19 is probably a good example of such a zoonotic diseases because it is thought most likely to have originated from bats. Other diseases like Ebola, Rift Valley fever, brucellosis and cysticercosis are also considered to be zoonotic. These diseases impose a huge burden on people and the global economy. 


Together with national and international partners, scientists at the International Livestock Research Institute (ILRI) carry out research towards improving the control of zoonoses through zoonotic disease modelling, risk mapping, surveillance and use of decision support tools. 


The annual global cost of zoonotic diseases is estimated at USD 500 billion, in terms of lives lost and economic slowdowns, compared to USD 20 billion per year for preventive actions. Increased investment in risk-based animal health services is crucial in the battle against zoonotic diseases.

Key messages

  • People can acquire zoonotic diseases from direct or indirect contact with animals and from livestock products. In some cases, when a disease jumps species from animals to humans it becomes adapted to humans as it spreads as a human-only disease. For example, HIV was originally a zoonotic disease which mutated to become a human-to-human disease. In other cases, such as rabies, animals remain the source of infection.
  • Zoonoses are more common than most people realize. On average, a new zoonotic disease emerges every four months, although few in recent memory have been as globally threatening as COVID-19.
  • Animal health systems remain poorly resourced to contribute effectively to One Health interventions to prevent and control zoonotic diseases. We need to engage in better surveillance and monitoring of animal diseases and conduct better vaccination and food safety programs.
  • The emergence of COVID-19 underlines the importance of taking a One Health approach, based on the premise that animal and human health and the ecosystems they share are inextricably linked and must be addressed together.

Experts working on zoonoses

Bernard Bett

Bernard Bett

Senior scientist, Animal and human health

Delia Grace

Delia Grace

Professor Food Safety Systems, NRI; joint appointed scientist, ILRI

Elizabeth (Annie) Cook

Elizabeth (Annie) Cook

Senior Scientist - Epidemiology

Eric Fevre

Eric Fevre

Professor of Veterinary Infectious Diseases, Institute of Infection and Global Health, University of Liverpool and Jointly Appointed Principal Scientist, ILRI

Florence Mutua

Florence Mutua

Scientist

Fred Unger

Fred Unger

Regional Representative - East and Southeast Asia

Hung Nguyen-Viet

Hung Nguyen-Viet

Co-Leader, Animal and Human Health Program

James Akoko

James Akoko

Field Officer

Kristina Roesel

Kristina Roesel

Senior scientist, Animal and human health

Lian Thomas

Lian Thomas

Lecturer Veterinary Public Health, University of Liverpool & Jointly Appointed Scientist, ILRI

Nicholas Ngwili

Nicholas Ngwili

Post-Doctoral fellow - Neglected Zoonotic diseases

Nicoline de Haan

Nicoline de Haan

Director, CGIAR GENDER Platform

Sinh Dang-Xuan

Sinh Dang-Xuan

Post-doc scientist

Siobhan Mor

Siobhan Mor

Reader in One Health