The spread of Zika virus, an arbovirus or mosquito-borne virus infection to the West has been highlighted in an article in the New England Journal of Medicine.
International travel and overcrowding are some of the reasons that have resulted in the appearance of four mosquito-borne diseases in the Western world in the last 20 years. After dengue, chikungunya and West Nile virus, the latest entrant is the Zika virus, with the first cases reported in Brazil and Puerto Rico in May and December 2015, respectively.
‘Zika virus disease is a newly emerged mosquito-borne disease that has similar clinical signs to dengue, and may be misdiagnosed in areas where dengue is common.’
AdvertisementSeveral similarities have been observed between zika virus and the other viral infections. It has been noted that Zika infections occur in areas that have recently been plagued by chikungunya infection. Like yellow fever, dengue and chikungunya infections, Zika also spreads through the bite of the Aedes aegypti mosquito. The mosquito breeds in fresh stored water in homes, and bites during the daytime.
Zika usually causes a mild disease with symptoms similar to dengue. Symptoms include fever, muscle aches, rash, joint pains and conjunctivitis or sore eyes. However, several people with Zika have suffered from a neurological problem called Guillain-Barrι syndrome, which could possibly be a complication of Zika. There is also a concern that, unlike the other viral infections, Zika may cause birth defects- in Brazil, several babies have been born with small heads since the appearance of the infection last year.
Diagnosis of Zika is made on clinical basis, but it may be confused with dengue or chikungunya due to similar symptoms. The reverse transcriptase polymerase chain reaction test may be used to differentiate it from other viral infections. This test is however currently available only in certain centers.
Similar to other viral infections like dengue and chikungunya, treatment of Zika is currently non-specific, with bed rest and supportive care. Unlike dengue, Zika is not known to cause bleeding. However, to be on the safe side, medications like aspirin have to be avoided till dengue has been ruled out. A vaccine to prevent Zika is not available, and even if developed, its clinical utility in vaccinating large populations will have to be established.
Though currently there is no specific drug for the treatment of Zika infection, experts feel that it would be more useful to develop antiviral drugs that will be effective against more than one viral infections, rather than trying to develop one drug against each viral infection.
Untill no specific treatment is available, prevention forms an important aspect in the management of viral mosquito-borne diseases. Prevention of Zika and other mosquito-borne viral infections involves preventing mosquito bites by using mosquito screens, insect repellents and cleaning up of mosquito-breeding sites. The last step may not always be possible in crowded places with poor sanitation where, unfortunately, the infection is commonly noted.
Reference:Fauci AS and Morens DM. Zika Virus in the Americas Yet Another Arbovirus Threat January 13, 2016 DOI: 10.1056/NEJMp1600297