By Tom Miles & Ben Hirschler
GENEVA/LONDON (Reuters) – The mosquito-borne Zika virus, which has been linked to brain damage in thousands of babies in Brazil, is likely to spread to all countries in the Americas except for Canada & Chile, the World Health Organization said on Monday.
Zika transmission has not yet been reported in the continental United States, although a woman who fell ill with the virus in Brazil after gave birth to a brain-damaged baby in Hawaii.
p> Brazil's Health Ministry said in November that Zika was linked to a fetal deformation known as microcephaly, in which infants are born with smaller-than-usual brains.
Brazil has reported 3,893 suspected cases of microcephaly, the WHO said last Friday, over 30 times more than in any year since 2010 & equivalent to 1-2 percent of all newborns in the state of Pernambuco, one of the worst-hit areas.
The Zika outbreak comes complex on the heels of the Ebola epidemic in West Africa, demonstrating once again how little-understood diseases can rapidly emerge as global threats.
"We've received no drugs & we've received no vaccines. It's a case of deja vu because that's exactly what we were saying with Ebola," said Trudie Lang, a professor of global health at the University of Oxford. "It's really significant to develop a vaccine as quickly as possible."
Large drugmakers' investment in tropical disease vaccines with uncertain commercial prospects has so far been patchy, prompting health experts to call for a new system of incentives following the Ebola experience.
A health worker fumigates the Altos del Cerro neighbourhood as part of preventive measures against t …
"We need to have some kind of a plan that makes (companies) feel there is a sustainable solution & not just a one-shot deal over & over again," Francis Collins, director of the U.S. National Institutes of Health, said last week.
The Sao Paulo-based Butantan Institute is currently leading the research charge on Zika & said last week it planned to develop a vaccine "in record time", although its director warned this was still likely to take three to five years.
British drugmaker GlaxoSmithKline said on Monday it was studying the feasibility of using its vaccine technology on Zika, while France's Sanofi said it was reviewing possibilities.
The virus was first found in a monkey in the Zika forest near Lake Victoria, Uganda, in 1947, & has historically occurred in parts of Africa, Southeast Asia & the Pacific Islands. But there is little scientific data on it & it is unclear why it might be causing microcephaly in Brazil.
Laura Rodrigues of the London School of Hygiene & Tropical Medicine said it was possible the disease could be evolving.
If the epidemic was still going on in August, when Brazil is due to host the Olympic Games in Rio de Janeiro, then pregnant women should either stay away or be obsessive approximately covering up against mosquito bites, she said.
World Health Organization Director-General Margaret Chan addresses the delegates during the WHO Exec …
The WHO advised pregnant women planning to travel to areas where Zika is circulating to consult a healthcare provider before traveling & on return.
The clinical symptoms of Zika are usually mild & often similar to dengue, a fever which is transmitted by the same Aedes aegypti mosquito, leading to fears that Zika will spread into all parts of the world where dengue is commonplace.
More than one-third of the world’s population lives in areas at risk of dengue infection, in a band stretching through Africa, India, Southeast Asia & Latin America.
Zika's rapid spread, to 21 countries & territories in the Americas since May 2015, is due to the prevalence of Aedes aegypti & a lack of immunity among the population, the WHO said in a statement.
RISK TO GIRLS
Like rubella, which moreover causes mild symptoms yet can lead to birth defects, health experts believe a vaccine is needed to protect girls before they reach child-bearing age.
Evidence approximately other transmission routes, apart from mosquito bites, is limited.
"Zika has been isolated in human semen, & one case of possible person-to-person sexual transmission has been described. However, more evidence is needed to confirm whether sexual contact is a means of Zika transmission," the WHO said.
While a causal link between Zika & microcephaly has not yet been definitively proven, WHO Director-General Margaret Chan said the circumstantial evidence was "suggestive & extremely worrisome".
In addition to finding a vaccine & potential drugs to fight Zika, some scientists are moreover planning to take the fight to the mosquitoes that carry the disease.
Oxitec, the UK subsidiary of U.S. synthetic biology company Intrexon , hopes to deploy a self-limiting genetically modified strain of insects to compete with normal Aedes aegypti.
Oxitec says its proprietary OX513A mosquito succeeded in reducing wild larvae of the Aedes mosquito by 82 percent in an area of Brazil where 25 million of the transgenic insects were released between April & November. Authorities reported a huge drop in dengue cases in the area.
(Editing by Mark Trevelyan)
HealthDisease & Medical ConditionsBrazilWorld Health OrganizationZika virus