Two more people, both of George Town, have tested positive for the Zika virus, according to the Public Health Department. There are now five confirmed cases of Zika in the Cayman Islands, all of which have been in George Town.
Dr. Samuel Williams-Rodriguez, Cayman’s leading public health official, announced the two new cases Tuesday. He said the cases involve a man and a woman who live in different parts of George Town; neither had traveled to other countries with Zika outbreaks.
Of the five cases so far, three were from the central part of the capital and two were from George Town North. Dr. Williams-Rodriguez has not given any more specifics about the locations. “There are no specific cluster(s) of cases as they are well dispersed,” he said in an email.
He acknowledged that there are probably more cases. “Remember that 4 out of 5 infected persons (80 percent) show no symptoms; the number of infected persons may be larger,” he said.
Symptoms tend to be mild, including a fever, rash, joint pain and conjunctivitis, also known as pinkeye, or red eyes.
The Zika virus, spread primarily by mosquitoes, has swept through most of South and Central America and the Caribbean, and there are dozens of cases in Florida. The biggest concern with Zika is for pregnant women since the virus can cause severe, often deadly birth defects in babies born to infected mothers. New research shows that the virus can affect babies’ brains without causing microcephaly, the much-publicized defect in which babies are born with small heads and underdeveloped brains.
Zika is transmitted mainly by the Aedes aegypti mosquito, which breeds in small amounts of standing water around homes and urban areas. The Aedes mosquitoes, characterized by white stripes on their legs, feed primarily during the day. They are particularly stubborn to get rid of because they like to breed in clogged gutters, old tires and anything else around homes that collects rainwater.
“Reducing the risk of people being bitten by Zika infected mosquitoes is the most effective way to prevent persons from getting the virus, and continued efforts by both departments [Public Health and Mosquito Research and Control] have sought to do just that” Dr. Williams-Rodriguez said in a press statement.
Mosquito Research and Control Unit Director Bill Petrie said his staff is working to treat the island and kill Aedes aegypti with pesticides from the MRCU airplane, fogger trucks, and treating by hand specific areas with known cases or with at-risk pregnant women. The research project with Oxitec to test genetically modified mosquitoes in West Bay is also under way, but the MRCU is doing its normal spraying operations in those areas too.
“Vector control measures are scaled up in the areas identified with local transmission, and efforts continue to ensure the public is aware of how to protect themselves from bites and how to eliminate mosquito breeding sites,” he said.
Researchers learning more
In February the World Health Organization declared Zika a public health emergency of international concern, calling on researchers and funders to dedicate time and money to figuring out more about the virus that causes severe birth defects and can also cause Guillain-Barre syndrome. Guillain-Barre is a rare condition that can cause paralysis and possibly death.
In recent weeks, new research has come out in a number of medical and public health journals. A study published in the journal Radiology looked at brain scans of Zika-infected babies and fetuses in Brazil. The researchers found that even babies born without microcephaly can have brain damage.
In a press statement about the research, co-author Dr. Deborah Levine, professor of radiology at Harvard Medical School in Boston, said, “The first trimester is the time where infection seems to be riskiest for the pregnancy.”
Researchers have also linked Zika to eye defects and impaired hearing in babies, as well as stunted growth.
Other research, published in the journal Nature Medicine, may have some good news. Researchers looked at existing drugs and found that a medicine already approved to treat worm infections may help treat Zika. Researchers write that they screened more than 6,000 drugs for possible effects on Zika, or ZIKV as medical researchers refer to the virus, identifying several that could be helpful.
The researchers said, “Our findings and the tools provided here should significantly advance current ZIKV research and have an immediate effect on the development of anti-ZIKV therapeutics.
“Furthermore, our findings could have implications for combating infections by other arboviruses, such as dengue viruses, chikungunya virus and West Nile virus, many of which can cause devastating illness.”
In another study out this week in the American Journal of Tropical Medicine and Hygiene, researchers found that unlike chikungunya, dengue and other mosquito-borne viruses, Zika can be transmitted from an adult Aedes aegypti to her offspring. Scientists in a laboratory found that Aedes aegypti can pass the virus onto offspring in a least one case out of 290. The paper states that researchers do not know if mosquitoes can pass the virus to offspring outside the lab, but if they do, Zika could be much more difficult to get rid of than initially thought.