Mosquito-borne Zika Virus

The Zika virus is similar to dengue with symptoms such as fever, joint and muscle pain, conjunctivitis, headache, weakness, rash and swelling of the lower limbs.

The incubation period of the Zika virus is usually 3-12 days after being bitten by an infected mosquito, symptoms last for 4-7 days.

Mosquito prevention is key. Clean up your surroundings to prevent mosquito breeding.

 

Situation Summary

The Zika virus was first isolated in 1947 in Zika Forest (Uganda), in a Rhesus monkey during a study of the transmission of wild yellow fever. It was first isolated in humans in 1952 (Uganda, Tanzania). In 1968 the virus was detected in human samples in Nigeria.

In 2007 the first major outbreak of Zika virus fever occurred on the island of Yap (Micronesia) where 185 suspected cases were reported, of which 49 were confirmed and 59 were considered probable. The outbreak lasted 13 weeks (April to July). The probable vector was identified as being Aedes hensilii, however the presence of the virus in the mosquito could not be determined.

Subsequently an outbreak in French Polynesia, which began at the end of October 2013. Around 10,000 cases were registered, of which approximately 70 were severe cases, including neurological (Guillain Barré syndrome, meningoencephalitis) or autoimmune (thrombo-cytopenic purpura, leukopenia) complications. An investigation was carried out to determine the association between these complications and primary or secondary co-infection with other flaviviruses, especially dengue virus. The vectors responsible for transmission were Aedes aegypti and Aedes polynesiensis. In 2014, cases were also recorded in New Caledonia and in the Cook Islands.

To date, no death attributed to Zika virus infection has been reported in any of the outbreaks.

In the past seven years, cases in travelers have sporadically been reported (Thailand, Cambodia, Indonesia and New Caledonia).

In February 2014, the public health authorities of Chile confirmed that there was a case of autochthonous transmission of Zika virus infection in Easter Island (Chile). It coincided with the presence of other foci of transmission in the Pacific Islands: French Polynesia, New Caledonia, and the Cook Islands. The presence of the virus was reported until June of the same year and was not detected later.

Currently, the public health authorities of Brazil are investigating a possible transmission of the Zika virus in the northeast of the country.

The recent outbreaks of Zika fever in different regions of the world, demonstrate potential spread of this arbovirus across territories where the vectors (Aedes) are present.