A disease expert in Cambodia said on Friday that although the Zika virus—which has recently been linked to birth defects and paralysis in South America—had circulated in Cambodia in the past, there had been no reported cases of the virus here for three years, though authorities were continuing to monitor for evidence of it.
Symptoms of Zika, which is transmitted by mosquitoes, usually include fever, a rash and headaches.
Recently, however, a more serious form of the virus has been linked to paralysis and severe birth defects in Brazil.
After a Thai man in Taiwan was diagnosed with Zika this week, the Taiwan Center for Disease Control issued a travel advisory warning for five countries in the region, including Cambodia.
Didier Fontenille, the director of Institute Pasteur in Phnom Penh, said on Friday that health officials here were watching the situation closely.
He said that despite the fact that there had been no evidence of Zika in Cambodia for three years, it was “very likely still present.”
“It is very difficult, almost impossible, to know if it is present because it is not serious,” he said, adding that because most Zika symptoms were relatively mild, many people did not go to the hospital when they developed them.
About 4,000 babies were born in Brazil in 2015 with microcephaly, a condition in which the head is abnormally small, which Brazilian authorities have blamed on a outbreak of Zika, the New York Times has reported.
The Times also said that the virus was being linked to cases of Guillain-Barre syndrome, a rare disorder that causes the body’s immune system to attack the nerves, which can result in paralysis and death.
Mr. Fontenille said that although the precise mechanism of the outbreak in Brazil was still unclear, it was possible that it was caused by a mutation that created a more serious strain of Zika—something that could also theoretically occur in Cambodia.
“With viruses it is always complicated. The virus may change and become more severe in the future,” he said.
“We have to be careful and aware of certain changes. It’s the reason why we continue to check if the virus is present in Cambodia.”