MENTION the word Zika and people immediately conjure images of babies born with small, truncated like a pyramid head - microcephaly, and almost always the countries in South America especially Brazil to the fore. And yet many experts in the medical field all over the world especially epidemiologists have this collective question; why did a virus that existed for many years in many parts of the world suddenly became more problematic and destructive when the virus reached Latin America.
A case in point is the Zika cases in Asia which virtually went unnoticed when the virus reached Asia in the 1960s.. Or the discovery of a more virulent strain of Zika virus from an outbreak in 2010 in Cambodia. But it was the high rate of microcephaly among babies born in Brazil that drew worldwide attention and worry from international health organization
Zika is believed to be have appeared in Latin America during the last few months of 2013., possibly by soccer players from French Polynesia competing in a tournament in Brazil. Then the virus is suspected to have undergone various types of mutation especially the S139N which is pointed to as the sole cause of birth defects among children born to women infected by mosquitoes during pregnancy, especially in the first trimester - first three months of pregnancy.
As to why, most cases in Brazil? Some scientists in the field of genetics proposed the possibilities including unique genetic make-up or even just a previous exposure to a mosquito-borne disease. At this juncture, it is well to emphasize that of course, there are many causes of microcephaly. For one, severe malnutrition of the mother would result to premature babies or SGA - small for gestation babies, meaning even if the pregnancy has reached full term ( 38-42 weeks), the babies head could be deformed as when the mother contracted toxoplasmosis or German measles on her first trimester.
The researchers noticed that strains of the Zika virus without the S139N mutation caused less and milder form of the disease, But the virus with the S139N mutation killed more mice annd caused more brain damage to brain cells and more severe microcephaly.. Thus at the moment, with the increasing rates of viral diseases - dengue, Japanese encephalitis and Zika, experts in the field of microbiology, and pharmacology consulting with geneticists, are working 24/7 to come up with strategies to win the war against these microorganisms, hopeful with vaccines that give lifelong immunity and medicines that would cure and eradicate the illness with no complications at all.
These viral illnesses are in our neighborhood. Lets us be all vigilant in their prevention while we strengthen our immune system.