On Thursday, the City of Lubbock Health Department announced a case of travel-related Zika virus has been confirmed in a Lubbock County resident. Zika virus, primarily transmitted by mosquitoes, was first discovered in Uganda in 1947. For decades, it was known as a short-lived, relatively mild illness with no long-lasting effects. In September, Brazilian doctors noticed a 1,400 percent spike in congenital brain deformities in a part of Brazil that experienced a Zika outbreak months earlier.
“Whether Zika virus has shifted or drifted in its antigenic properties, we really don’t know with the current outbreak that’s going on. There’s something that’s caused it to be much more widespread, whether it’s increased mosquito numbers, environmental factors that may influence more mosquitoes being infected with it or more mosquitoes in an area”said Steven M. Presley, professor, The Institute of Environmental and Human Health at Texas Tech University.
The first case of Zika virus in the United States was confirmed in early February in Dallas, when that city’s health officials reported a man infected a partner during sex. Brazilian scientists then announced they had found live strains of the virus in the urine and saliva of infected individuals.
“Probably the fetuses and newborns with microcephaly are the most tragic outcome of the disease, but they’re finding more and more information on neurological involvement in Brazil in adults and not just infants,” Presley said.
Unlike with West Nile virus, which requires an animal (bird) host to amplify the virus between mosquitoes and humans, Zika virus can amplify in humans. This makes the transmission cycle much faster.
“Because there’s not an intermediate amplifying host and only one in five people are symptomatic with Zika virus, the transmission cycle is sped up, and amplifying hosts may not be recognized. You have these amplifying hosts out there promulgating the virus and mosquitoes are feeding and biting somebody else without you ever knowing it’s occurring in the area,” Presley said.
Only one in five people infected with Zika virus shows symptoms. Because those are similar to the symptoms of influenza, many people who show symptoms are never properly diagnosed, which makes the disease difficult to track. According to Presley, little is known about the Zika Virus, especially the full spectrum of the mosquito transmission and hosts dynamics.
According to health officials, the mosquitoes that transmit Zika are Aedes aegypti and Aedes albopictus. They are day-biting, human-loving and have biologies and behaviors different from many of the species that vector West Nile virus and St. Louis encephalitis virus.
The mosquitos that transmit and carry the virus are container breeders: Vases at cemeteries, toys in the backyard, garbage – a Styrofoam coffee cup thrown in the alley. Just a little bit of water can produce a lot of those mosquitoes, while the typical West Nile and St. Louis encephalitis vectors are pond, puddle, standing water, established water breeders.
So far, no mosquitoes in Lubbock have tested positive for the disease.