But sexual transmission, experts said, adds a new level of difficulty to detecting and preventing Zika outbreaks, which may require not just mosquito control but also safe-sex education. Health officials now face the prospect of stopping an infection that is usually silent and for which there are no widely available tests; it may be transmissible sexually, yet there may be no sign until a child is born.
“This opens up a whole new range of prevention issues,” said Dr. William Schaffner, chief of preventive medicine at Vanderbilt University Medical School.
Still, he cautioned that sexual transmission is probably rare compared with the viral spread by mosquitoes, taking place in more than 20 countries and territories in Latin America and the Caribbean.
“Mosquito transmission is the highway, whereas sexual transmission is the byway,” Dr. Schaffner said. “Sexual transmission cannot account for this sudden and widespread transmission of this virus.”
The Guardian (UK): Rio Olympics committee warns athletes to take precautions against Zika virus
Olympic organisers have insisted that the 2016 Games in Rio de Janeiro this August will not be affected by the outbreak of the Zika virus in Brazil, but also warned athletes and visitors to smother themselves in mosquito repellent to minimise the risks.
At a press conference staged the day after the World Health Organisation declared that the clusters of brain-damaged babies – linked to but not proven to be caused by the Zika virus – constituted a global health emergency, the Rio 2016 organising committee said it would follow the guidelines issued by international and local authorities, but stressed this has not so far included a travel ban.
“At the moment we have a new problem and are facing this with the help of the government and the authorities. Our priority is the health of the athletes, the health of all Brazilians and protection for all those who work at the Olympics,” said spokesman Mário Andrada. “We are sure this battle can be won and will not affect the Games.”
The buildup to the event, which will start in a little over six months on 5 August, have been overshadowed by the alarming spread of the virus. Since Zika was first identified in Brazil last April an estimated 1.5 million people in the country have been infected by the mosquito-borne disease.
Companies announce new Zika vaccine initiatives
Two vaccine makers, Sanofi Pasteur and NewLink Genetics, today announced efforts to develop vaccines against Zika virus infection that will springboard off existing technologies.
In related news, Honduras yesterday declared a national emergency over an expanding Zika virus infection outbreak, while Thailand confirmed its first locally acquired case.
Officials in Texas have reported the first case of Zika contracted in the US mainland, and said that the virus was sexually transmitted. If confirmed, the case would be only the second documented example of the virus being passed between humans through sexual contact.
Officials at the Centers for Disease Control and Prevention confirmed the Zika infection, while Dallas County officials said they performed the “public health follow-up” to determine that the infection was sexually transmitted.
In an email to the Guardian, the CDC also warned for the first time that pregnant women or those hoping to become pregnant should “consult with their healthcare professional if their partner has had exposure to Zika virus”.
“Based on what we know now, the best way to avoid Zika virus infection is to prevent mosquito bites AND to avoid exposure to semen from someone who has been exposed to Zika virus or has been ill from Zika virus infection,” the CDC wrote. It is unclear how long the virus may linger in men’s semen after virus symptoms subside.
French drugmaker Sanofi Pasteur has started work to develop a vaccine against the Zika virus, the company said Tuesday. Alarm over the disease is spreading throughout the Americas because of its potential link to birth defects and neurological problems, and no vaccine, cure or reliable diagnostic test for the virus exists.
Despite growing fears over the virus and its effects, developing a vaccine is a process experts have said could take years. The World Health Organization declared the Zika virus outbreak a public health emergency of international concern Monday, citing an unproved but strongly suspected link between the virus and the birth defect known as microcephaly. Director-General Margaret Chan emphasized the need for “a coordinated international response … to minimize the threat in affected countries and reduce the risk of further international spread.” She pointed to “the lack of vaccines and rapid and reliable diagnostic tests, and the absence of population immunity in newly affected countries,” as “further causes for concern.”
Sanofi Pasteur, the vaccines division of Sanofi SA, has previously worked on developing and licensing vaccines for other mosquito-borne viruses like Dengue and yellow fever — achievements the company said would speed the process of finding a vaccine for the Zika virus.
“Sanofi Pasteur is responding to the global call to action to develop a Zika vaccine, given the disease’s rapid spread and possible medical complications,” Nicholas Jackson, the research head of Sanofi Pasteur, said in a statement.
Sanofi Press Release: SANOFI PASTEUR TO LEVERAGE ITS STRONG VACCINE LEGACY IN HUNT FOR ZIKA VACCINE
Straits Times (Singapore): Major outbreak of Zika virus unlikely in Singapore: Expert
The Zika virus will come to Singapore, but is unlikely to result in major outbreaks here in the way that dengue has, an infectious disease expert has told The Straits Times.
The virus has infected millions of people in South America, with Brazil claiming it is the reason more than 4,000 babies have been born with abnormally small heads since October last year.
But Dr Lim Poh Lian, head of the infectious diseases department at the Institute of Infectious Diseases and Epidemiology at Tan Tock Seng Hospital, said that when Zika arrives here, it is likely to have a similar effect as chikungunya.
With no specific federal guideline yet in place to control the spread of the Zika virus in the United States, some mosquito-heavy states like Florida are stepping up spraying and education programs. But the North and West have yet to boost prevention.
Only one out of the more than 30 confirmed cases of Zika in the country appears to have been transmitted locally, in Dallas, Texas. Public health officials are bracing for the time when warmer weather increases the number of mosquitoes that can transmit the virus by biting an infected person and spreading it to others.
The types of mosquitoes carrying the Zika virus, Aedes aegypti and Aedes albopictus, are common in Florida, where mosquito season is year-round, and along the coast of the Gulf of Mexico, including Houston.
Florida seems to be leading so far in intensifying efforts. Hillsborough County, located on Tampa Bay on Florida’s west coast, is paying workers overtime as it steps up spraying, mosquito monitoring, and misting in the area of the home of someone who had Zika, said Carlos Fernandes, director of county mosquito control.