by Larry Smith
When Zika and other mosquito-borne viruses such as Dengue and Chikungunya invade a region without prior immunity, between 25-65% of the population will become exposed.
So there’s no point counting confirmed cases. Doctors say the current Zika outbreak in the Bahamas should reasonably be expected to affect tens of thousands of people. And as a result, the Centers for Disease Control in Atlanta have issued a travel alert.
The virus is primarily spread by mosquitoes, but it is also spread from mother to baby during pregnancy, and during sexual intercourse. The CDC has advised pregnant women not to travel to the Bahamas, and travellers are being encouraged to use condoms or not have sex at all while in the Bahamas.
According to Tourism Director Joy Jibrilu, “when it comes to the management of threats to public health, we must (act) with transparency and openness. We are keenly aware of what the implications are."
Zika has been recognized for decades in Africa, so a significant proportion of the population there has been exposed and is therefore immune. Unless the virus mutates, only sporadic cases will continue to occur.
But the Bahamas - and other countries in the Western Hemisphere and Europe - have never been previously exposed and so are fertile ground for the Zika virus, as long as the mosquito vectors are around.
"We see cyclical infections with Dengue as the number of non-immune people grows between epidemics,” one local doctor told me. "Hopefully, this epidemic will pass within the next 12 months or so, but until it does the government should focus on discouraging women from becoming pregnant."
This is because the major complication from this generally mild disease is the effect it can have on a developing fetus. There is evidence that Zika infection in pregnancy causes birth defects, including brain abnormalities.
Scientists are working on 18 different vaccines, but only one has made it to testing phase. An effective vaccine is not expected to be ready before 2018.
The best way to protect yourself is to use mosquito repellents and remove breeding sites - which means any outdoor container filled with water. Public health authorities are also fogging communities with pesticides.