The World Health Organization on Monday is convening a meeting in Geneva to determine whether a global health emergency should be declared for the Zika virus.
WHO is responding in a more pro-active manner to the relatively minor mosquito-borne virus in contrast to its slow response to the lethal 2013 outbreak of Ebola in West Africa, for which the U.N. agency faced heavy criticism.
Zika, suspected of causing a surge of birth defects in South America, is “spreading explosively” in the Americas, according to the WHO.
The U.N. agency also believes the disease has been more common in Southeast Asia than the smattering of cases reported in the region in the past several years.
Zika, usually mild and rarely fatal with symptoms often mistaken for other mosquito-borne viruses such as dengue and chikungunya, has “widespread distribution" across Thailand, according to an article last year in the American Journal of Tropical Medicine and Hygiene. But Thailand has only reported one case this year.
It is spread through the Aedes aegypti mosquito, responsible for dengue, yellow fever and other tropical diseases.
Thailand has seen a sharp increase in dengue in recent years.
A popular 37-year-old TV actor, Thrisadee “Por” Sahawong, died last month of complications related to dengue fever after more than two months in a coma, shining a fresh spotlight in the kingdom on the disease, which was first documented in the 1950s during epidemics in Thailand and the Philippines.
The Zika virus, first detected in a rhesus monkey in Uganda in 1947, had been limited to rare cases in human populations in Africa and Asia until an unprecedented outbreak on an island in the southwestern Pacific in 2007.
“It was something kind of unique, along with the fever and rash that we were starting to see, as well as patients having some kind of this typical rash around the earlobe,” said Dr. James Edilyong, the medical staff chief for the state of Yap in Micronesia. “That's when it kind of indicated to us that we need to more find about this kind of condition.”
The general population on the island – which is home to little more than 10,000 people – was subsequently tested. It was discovered nearly three-fourths of those aged 3 and older had contracted the virus. But most did not realize it.
“A lot of them were basically sub-clinical. They didn't feel the need to come to the hospital. Maybe some of them didn’t even feel any difference, probably just thinking it's just a flu or something – just feeling a little bit unwell,” Edilyong told VOA Monday.
In late 2013, another large outbreak erupted in French Polynesia, with the first links to the virus causing Guillain-Barré syndrome, a neurological illness with paralysis as its main feature.
But the relatively obscure disease did not end up on the front pages globally until the latest outbreak emerged in Brazil – where several thousand cases have been reported since last year – of a suspected link to infected pregnant women giving birth to babies with microcephaly, a fetal deformity that causes abnormally small heads.
There were no such defects linked to Zika on Yap after the 2007 outbreak, but officials there, in view of what has emerged out of Brazil, are now examining birth records more closely, Edilyong told VOA.
There has also been no link so far between Zika and microcephaly in Southeast Asia, according to the WHO's regional office here.
WATCH: Related Zika virus video
Malaysian and Singaporean public health officials have warned of a high risk of contagion if the virus is introduced there.
The Philippines health department is calling Zika a “real and present” risk amplified by weather conditions caused by the El Niño phenomenon that will likely lead to more ideal conditions for mosquitoes to breed.
Governments in the Americas and the Caribbean, including Colombia, Ecuador, El Salvador, Jamaica and Puerto Rico, have warned women to delay conceiving until the Zika outbreak is brought under control.
No treatment or vaccine is available, although a Canadian researcher has been quoted as saying one might be ready within this year. Medical experts, however, say it could take several years of testing a vaccine before it is deemed safe.