On July 3, 2025, local time in Colombo, Sri Lanka, a health worker sprays insecticide to control the breeding of mosquitoes and curb dengue fever and Zika virus. Photo by Visual China.
On July 22, experts from the World Health Organization issued an alert about the vector-borne disease Zika fever, reminding countries to prepare for potential large-scale outbreaks.
At a press conference held in Geneva, Diana Alvarez, head of the WHO’s Insect-Borne Viral Diseases Group, stated that there are currently transmission cases of Zika virus found in 119 countries and regions, affecting approximately 5.5 million people at risk. There is also a possibility of widespread outbreaks, putting pressure on the health system.
According to Alvarez, about 20 years ago, the Zika fever outbreak in the Indian Ocean region affected approximately 500,000 people. Symptoms include high fever, joint pain, fatigue, and rarely, death.
Since the beginning of this year, it is estimated that about one-third of the population in Leyte Island, France’s territory in the Indian Ocean has been infected with the Zika virus; transmission has also occurred in Southeast Asian countries such as India and Bangladesh. Additionally, European countries including France and Italy have recently reported imported cases and identified local transmissions.
Alvarez mentioned that mosquitoes carrying the Zika virus are present in most tropical countries. The WHO is supporting member states in developing laboratory diagnostic methods, training personnel, strengthening healthcare systems, and expanding surveillance to track and control the Zika fever outbreak.