Question

Zika virus infection, a zoonotic disease, produced somewhat sizable outbreaks recently in certain areas of Central America, but not in the U.S.(although they were some infected individuals uncovered in the U.S.). Provide two plausible explanations for this dichotomy, and explain.

Answer 1

Zika virus is a disease caused by zika virus spread to the people primarily by the bite of infected Aedes species mosquito. The most common symptoms are fever, rash, joint pains, and conjuctivitis. The zika virus cause serious symptom during pregnancy causing birth defects called microcephaly.

Local mosquito borne transmission of zika virus has been reported in Central American territories such as Common wealth of Peurto Rico, virgin islands and American samoa.

No local borne cases has been reported in US states though some are been travel associated cases

Based on several studies this dichotomy in spread of disease in the 2 places is difference in the presence of mosquitoes, human hosts, and viruses increase the risk for mosquito-borne virus transmission. Passenger air travel, however, was less impactful. The most important factor being found that a lower regional GDP was the best predictor of Zika virus transmission, suggesting that Zika is primarily a disease of poverty.

Zika cases are more likely to occur in regions where people cannot afford to protect themselves from mosquitoes such as Africa and central america. The significant factor was negative regional gross domestic product (GDP) per capita for the prevalence of disease.

Answer 2

Zika viral infection spread can be by direct infection of the virus by the vector mosquito aedes aegipty to humans and from infected humans to another by this vector itself. The otherway is by the sexual contact of infected person to another or through pregnancy or blood transfusion.

The two possible ways that may lead to the dichotomy may be due to the absense of the vector mosquito. One of the main spread is due to the transmission of the virus by the aedes aegipty to a healthy human and from the infected human to a healthy human. There are few other mosquito category too. But aedes aegipty is the main mosquito responsible for this. If a vector mosquito is not present there are no possible. Other than central American countries when we look about U.S they maintain a good hygiene and the chances for the mosquito larvae to grow there is less. So the available vector mosquito are less. Due to this a vector transmission was not possible.

The other possible reason is that U.S was alert about the virus. The people who reported with the virus was mostly travelers. They should not come have come to contact with a sexual contact or blood transfusion. And thus not not transferred to the fetus by pregnancy. If an infected person doesn't come to contact with these possible routes there are no chances of getting infected. People are mostly educated and population density is less for U.S than central America. So in such a point of view spread by such a situation like multiple partners is less here and that may be one of the reason that kept U.S back from an outbreak.