Tag Archives: Zika

Race for Zika vaccine gathers momentum as virus spreads

(Reuters) – Companies and scientists are racing to create a Zika vaccine as concern grows over the mosquito-borne virus that has been linked to severe birth defects and is spreading quickly through the Americas.

Zika is now present in 23 countries and territories in the Americas. Brazil, the hardest-hit country, has reported around 3,700 cases of the devastating birth defect called microcephaly that are strongly suspected to be related to Zika.

The Geneva-based World Health Organization (WHO), stung by criticism that it reacted too slowly to West Africa’s Ebola epidemic, is convening an emergency meeting on Monday to help determine its response to the spread of the virus.

The U.S. Centers for Disease Control and Prevention has activated an emergency operations center staffed around the clock to address Zika, agency officials told Reuters.

On Thursday, the WHO forecast that as many as 4 million people in the Americas may become infected by Zika, lending new urgency to research efforts already under way. Vaccine developers made clear that a vaccine for widespread public use is at least months, if not years, away.

The closest prospect may be from a consortium including drugmaker Inovio Pharmaceuticals Inc that could have a vaccine ready for emergency use before year-end, according to one of its lead developers. Inovio’s share price jumped as much as 13 percent on Friday.

Canadian scientist Gary Kobinger told Reuters on Thursday the first stage of testing on humans could begin as early as August. If successful, the vaccine might be used during a public health emergency by October or November, said Kobinger, who helped develop a trial vaccine for the Ebola virus.

Privately owned vaccine developer Hawaii Biotech Inc said it began a formal program to test a Zika vaccine last fall as the virus started to gain traction in Brazil, although it has no timetable yet for clinical trials.

“Right now, we are in the pre-clinical stage, as I suspect everyone is,” Chief Executive Dr. Elliot Parks told Reuters.

Another private vaccine developer, Boston-based Replikins Ltd, said it was preparing to start animal studies on a Zika vaccine in the next 10 days. Data from the trials on mice and rabbits would likely be out in the next couple of months, Replikins Chairman Samuel Bogoch told Reuters.

“No one has the $500 million on hand to take it (a vaccine) all the way to human trials. Somewhere along the course we hope to have big pockets join us,” Bogoch said.

‘FIGHT THE MOSQUITO’

Zika had been viewed as a relatively mild illness until Brazilian health officials identified it as a matter of concern for pregnant women. While a direct causal relationship has not been established, scientists strongly suspect a link between Zika and thousands of children born in Brazil with abnormally small heads, brain defects and impaired vision.

There is no treatment for Zika infection. About 80 percent of those infected experience no symptoms, making it difficult for pregnant women to know whether they have been infected.

Efforts to combat Zika are focused on protecting people from being bitten and on eradicating mosquitoes, a tough task in many parts of Latin America, where people live in poverty and there are plentiful breeding grounds for the insect.

“We do not have a vaccine for Zika yet. The only thing we can do is fight the mosquito,” Brazilian President Dilma Rousseff said on Friday, reiterating her call for a national eradication effort.

Rousseff said tests for the development of a vaccine would begin next week at the Butantan Institute, one of Brazil’s leading biomedical research centers in Sao Paulo.

Zika has hit Brazil just as it prepares to host the Olympic Games in Rio de Janeiro on Aug. 5-21, an event that draws hundreds of thousands of athletes, team officials and spectators. The International Olympic Committee (IOC) assured teams on Friday the Olympics would be safe from Zika, but urged visitors to carefully protect themselves.

U.S. lawmakers have begun to press the Obama administration for details of its response to Zika. At least 31 people in the country have been infected, all of them after travel to affected countries.

“We need to ensure that federal agencies are working closely together and with the international community to stop its rapid spread,” said Republican Ron Johnson, chairman of the U.S. Senate Homeland Security and Governmental Affairs Committee.

The United States has two potential vaccine candidates and may begin human clinical trials by the end of 2016, U.S. officials said, but there will not be a widely available vaccine for several years.

(Reporting by Natalie Grover and Amrutha Penumudi in Bengaluru; Additional reporting by Julie Steenhuysen in Chicago, Karolos Grohmann in Berlin, Anthony Boadle in Brasilia, Jeffrey Dastin in New York; Writing by Frances Kerry; Editing by Will Dunham)

WHO says Zika ‘spreading explosively,’ 4 million cases a possibility

GENEVA (Reuters) – The Zika virus, linked to severe birth defects in thousands of babies in Brazil, is “spreading explosively” and could infect as many as 4 million people in the Americas, the World Health Organization (WHO) said on Thursday.

Director-General Margaret Chan told members of the U.N. health agency’s executive board the spread of the mosquito-borne disease had gone from a mild threat to one of alarming proportions. The WHO would convene an emergency meeting on Monday to help determine its response, she said.

“The level of alarm is extremely high,” Chan told the Geneva gathering.

“Last year, the virus was detected in the Americas, where it is now spreading explosively. As of today, cases have been reported in 23 countries and territories in the region,” Chan said, promising quick action from the WHO.

The agency was criticized last year for reacting too slowly to West Africa’s Ebola epidemic, which killed more than 10,000 people, and it promised to cut its response time.

“We are not going to wait for the science to tell us there is a link (with birth defects). We need to take actions now,” Chan said, referring to the condition called microcephaly in which babies are born with abnormally small heads and brains that have not developed properly.

There is no vaccine or treatment for Zika, which is like dengue and causes mild fever, rash and red eyes. An estimated 80 percent of people infected have no symptoms. Much of the effort against the illness focuses on protecting people from mosquitoes and reducing mosquito populations.

Developing a safe and effective vaccine could take a year, WHO Assistant Director Bruce Aylward said, and it would take six to nine months just to confirm whether Zika is the actual cause of the birth defects, or if the two are just associated.

“In the area of vaccines, I do know that there has been some work done by some groups looking at the feasibility of a Zika virus vaccine. Now something like that, as people know, is going to be a 12-month-plus time frame,” he said.

U.S. health officials said the United States has two potential candidates for a Zika vaccine and may begin human clinical trials by the end of this year, but there will not be a widely available vaccine for several years.

Marcos Espinal, head of communicable diseases at the Pan American Health Organization, the WHO’s Americas arm, forecast 3 to 4 million Zika cases in the Americas.

As the virus spreads from Brazil, other countries in the Americas are likely to see cases of babies with Zika-linked birth defects, according to Carissa Etienne, regional director for the Pan American Health Organization.

Brazil has reported around 4,000 suspected cases of microcephaly, vastly more than in an average year and equivalent to 1 to 2 percent of all newborns in the state of Pernambuco, one of the worst-hit areas.

The WHO’s Chan said that while a direct causal relationship between Zika virus infection and birth malformations has not yet been established, it is strongly suspected.

“The possible links, only recently suspected, have rapidly changed the risk profile of Zika from a mild threat to one of alarming proportions,” she said.

Health and law expert Lawrence Gostin of Georgetown University in Washington, who had urged the WHO to act, welcomed Chan’s decision to convene an expert meeting, calling it “a critical first step in recognizing the seriousness of an emerging epidemic.”

OLYMPICS CONCERNS

With Rio de Janeiro set to host the Olympics from Aug. 5 to Aug. 21, International Olympic Committee President Thomas Bach said the IOC will issue guidelines this week concerning Zika.

“We will do everything to ensure the health of the athletes and all the visitors,” Bach told reporters in Athens.

Dr. Anne Schuchat of the U.S. Centers for Disease Control and Prevention, said there have been 31 cases of Zika infection among U.S. citizens who traveled to areas affected by the virus.

“It’s possible and even likely that we will see limited outbreaks in the United States,” Schuchat said.

In Washington, U.S. Senator Edward Markey of Massachusetts called on the WHO and the U.S. Department of Health and Human Services to explain how they were tackling the virus because many Americans visit the affected region and more are expected to attend the Olympics.

White House spokesman Josh Earnest said President Barack Obama’s administration’s concern was focused mostly on pregnant women or women who could become pregnant, given the link to microcephaly.

Lufthansa, British Airways and JetBlue became the latest international carriers to offer rebookings or refunds for tickets to areas impacted by the virus.

Lufthansa and British Airways said they would offer pregnant women the opportunity to change their reservations to another destination or delay travel. They stopped short of offering complete refunds as several U.S. airlines have.

(Additional reporting by Kate Kelland in London; Additional reporting by Susan Heavey in Washington and Julie Steenhuysen in Chicago; Writing by Kate Kelland and Will Dunham; Editing by Mark Heinrich and Frances Kerry)

Zika reported in travelers who returned to California, Arkansas and Virginia

Travelers who recently returned to California, Arkansas and Virginia from foreign countries have tested positive for the Zika virus, health officials in those states announced Tuesday.

The Centers for Disease Control and Prevention (CDC) maintains that there haven’t been any people who have contracted the mosquito-borne virus in the United States, though there have been several cases where travelers got infected overseas and brought the virus back with them.

Zika is collecting the attention of public health officials because scientists are studying a possible link between the virus and a rare condition called microcephaly, in which children are born with smaller-than-usual heads. The birth defect can also be caused by other factors, the CDC says.

Still, the CDC has issued travel notices for 22 countries or territories where Zika is currently being spread, urging pregnant women to consider postponing any planned travel to those areas and asking all would-be travelers to “practice enhanced precautions” to prevent mosquito bites.

The three cases announced Tuesday all involved foreign travel.

In a statement, the Virginia Department of Health said the infection was confirmed in “an adult resident of Virginia who recently traveled to a country where Zika virus transmission is ongoing,” but did not elaborate. The infected individual was the state’s first imported Zika case, but isn’t at risk of transmitting the virus because it isn’t currently mosquito season in Virginia.

The Arkansas Department of Health said one of the state’s residents “recently traveled out of the country and had a mild case of Zika.” Officials confirmed the diagnosis late Monday afternoon.

“Arkansas has the kind of mosquitoes that carry Zika virus, so mosquitoes here in Arkansas can become infected with the virus if they bite someone who has Zika,” Dr. Nate Smith, the Arkansas Department of Health Director and State Health Officer, said in a statement. “For this reason, people traveling to countries with Zika should avoid mosquito bites for 10 days after they return.”

The Los Angeles County Department of Public Health said an adolescent girl who traveled to El Salvador last November was the county’s lone confirmed case of Zika, but she has recovered.

“At this time, local transmission is unlikely,” the department said in a statement. “It would require an Aedes mosquito biting a Zika infected person and then biting others.”

The CDC says only about 20 percent of people who are infected with Zika become ill and develop symptoms like fever, rash and joint pain. Most people fully recover from the illness in a week.

The possible link between Zika and microcephaly is a key component of the travel warnings.

The Brazilian Ministry of Health has investigated more than 4,100 microcephaly cases in the past 13 months, according to data released Wednesday. The ministry used to see fewer than 200 cases of the condition every year, though the numbers have surged since Zika arrived in May.

The Hawaii Department of Health has said a child who was recently born with microcephaly there had been infected with Zika, and his mother likely got the virus when she lived in Brazil.

The CDC says it will also be conducting a study to examine a possible link between Zika and Guillain-Barre Syndrome, a nerve disorder than can lead to muscle weakness and paralysis. Many fully recover from the syndrome, the CDC says, though it can be fatal in rare instances.

The World Health Organization is holding an information session on Zika tomorrow.

The organization says it’s possible the virus could cause epidemics in new areas it reaches because people don’t have immunity to it. There’s also currently no vaccine to prevent it.

U.S. boosts study of Zika, birth defect link as virus seen spreading

CHICAGO (Reuters) – U.S. health officials are stepping up efforts to study the link between Zika virus infections and birth defects in infants amid predictions for widespread circulation of the mosquito-borne virus within the United States during warmer months.

The U.S. Director of the National Institutes of Health on Tuesday called for intensified efforts to study the impact of Zika infections, citing a recent study estimating the virus could reach regions where 60 percent of the U.S. population lives.

The mosquito-borne virus has been linked to brain damage in thousands of babies in Brazil. There is no vaccine or treatment for Zika, a close cousin of dengue and chikungunya, which causes mild fever and rash. An estimated 80 percent of people infected have no symptoms, making it difficult for pregnant women to know whether they have been infected.

On Monday, the World Health Organization predicted the virus would spread to all countries across the Americas except for Canada and Chile.

In a blog post, NIH Director Dr. Francis Collins cited a Lancet study published Jan. 14 in which researchers predicted the Zika virus could be spread in areas along the East and West Coasts of the United States and much of the Midwest during warmer months, where about 200 million people live.

The study also showed that another 22.7 million people live in humid parts of the country where mosquitoes carrying the virus could live year round.

Given the threat, Collins said “it is now critically important to confirm, through careful epidemiological and animal studies, whether or not a causal link exists between Zika virus infections in pregnant women and microcephaly in their newborn babies.” Microcephaly results in babies being born with abnormally small heads.

Experts say there is still much to learn about Zika infections. For example, it is not clear how common Zika infections are in pregnant women, or when during a pregnancy a woman is most at risk of transmitting the virus to her fetus.

Collins said the National Institute of Allergy and Infectious Disease is conducting studies to more fully understand the effects of Zika in humans, and to develop better diagnostic tests to quickly determine if someone has been infected. The NIAID is also working on testing new drugs that might be effective against the virus.

The blog post was followed by the announcement on Tuesday of new guidelines from the U.S. Centers for Disease Control and Prevention providing instructions for pediatricians treating infants whose mothers may have been exposed to the virus during pregnancy.

In those guidelines, the CDC makes clear that Zika virus is considered a nationally notifiable condition, and instructs doctors to contact their state or territorial health departments to facilitate testing of potentially infected infants.

The guidelines for the care of infants affected by Zika infections follows CDC guidelines for caring for pregnant women exposed to Zika virus, which were first reported by Reuters. The CDC said last week it is trying to determine how many pregnant women may have traveled to affected regions in the past several months.

(Reporting by Julie Steenhuysen; Editing by James Dalgleish)

WHO warns Zika to spread across Americas, spurring vaccine hunt

GENEVA/LONDON (Reuters) – The mosquito-borne Zika virus, which has been linked to brain damage in thousands of babies in Brazil, is likely to spread to all countries in the Americas except for Canada and Chile, the World Health Organization said on Monday.

Zika has not yet been reported in the continental United States, although a woman who fell ill with the virus in Brazil later gave birth to a brain-damaged baby in Hawaii.

Brazil’s Health Ministry said in November that Zika was linked to a fetal deformation known as microcephaly, in which infants are born with smaller-than-usual brains.

Brazil has reported 3,893 suspected cases of microcephaly, the WHO said last Friday, over 30 times more than in any year since 2010 and equivalent to 1-2 percent of all newborns in the state of Pernambuco, one of the worst-hit areas.

The Zika outbreak comes hard on the heels of the Ebola epidemic in West Africa, demonstrating once again how little-understood diseases can rapidly emerge as global threats.

“We’ve got no drugs and we’ve got no vaccines. It’s a case of deja vu because that’s exactly what we were saying with Ebola,” Trudie Lang, a professor of global health at the University of Oxford, said on Monday. “It’s really important to develop a vaccine as quickly as possible.”

Large drugmakers’ investment in tropical disease vaccines with uncertain commercial prospects has so far been patchy, prompting health experts to call for a new system of incentives following the Ebola experience.

“We need to have some kind of a plan that makes (companies) feel there is a sustainable solution and not just a one-shot deal over and over again,” Francis Collins, director of the U.S. National Institutes of Health, said last week.

The Sao Paulo-based Butantan Institute is currently leading the research charge on Zika and said last week it planned to develop a vaccine “in record time”, although its director warned this was still likely to take three to five years.

RIO CONCERNS

The virus was first found in a monkey in the Zika forest near Lake Victoria, Uganda, in 1947, and has historically occurred in parts of Africa, Southeast Asia and the Pacific Islands. But there is little scientific data on it and it is unclear why it might be causing microcephaly in Brazil.

Laura Rodrigues of the London School of Hygiene and Tropical Medicine said it was possible the disease could be evolving.

If the epidemic was still going on in August, when Brazil is due to host the Olympic Games in Rio de Janeiro, then pregnant women should either stay away or be obsessive about covering up against mosquito bites, she said.

The WHO advised pregnant women planning to travel to areas where Zika is circulating to consult a healthcare provider before traveling and on return.

The clinical symptoms of Zika are usually mild and often similar to dengue, a fever which is transmitted by the same Aedes aegypti mosquito, leading to fears that Zika will spread into all parts of the world where dengue is commonplace.

More than one-third of the world’s population lives in areas at risk of dengue infection, in a band stretching through Africa, India, Southeast Asia and Latin America.

Zika’s rapid spread, to 21 countries and territories in the Americas since May 2015, is due to the prevalence of Aedes aegypti and a lack of immunity among the population, the WHO said in a statement.

RISK TO GIRLS

Like rubella, which also causes mild symptoms but can lead to birth defects, health experts believe a vaccine is needed to protect girls before they reach child-bearing age.

Evidence about other transmission routes, apart from mosquito bites, is limited.

“Zika has been isolated in human semen, and one case of possible person-to-person sexual transmission has been described. However, more evidence is needed to confirm whether sexual contact is a means of Zika transmission,” the WHO said.

While a causal link between Zika and microcephaly has not yet been definitively proven, WHO Director-General Margaret Chan said the circumstantial evidence was “suggestive and extremely worrisome”.

In addition to finding a vaccine and potential drugs to fight Zika, some scientists are also planning to take the fight to the mosquitoes that carry the disease.

Oxitec, the UK subsidiary of U.S. synthetic biology company Intrexon, hopes to deploy a self-limiting genetically modified strain of insects to compete with normal Aedes aegypti.

Oxitec says its proprietary OX513A mosquito succeeded in reducing wild larvae of the Aedes mosquito by 82 percent in an area of Brazil where 25 million of the transgenic insects were released between April and November. Authorities reported a big drop in dengue cases in the area.

(Editing by Mark Trevelyan)

CDC issues more travel notices about Zika virus

The Centers for Disease Control and Prevention (CDC) on Friday issued more travel notices about the Zika virus, warning travelers about the potential risks of the mosquito-borne illness.

The notices were issued one week after the CDC advised pregnant women who were planning to travel to 14 countries and territories where outbreaks of the virus were occurring to consider postponing their trips while scientists probe a potential tie between Zika and a rare birth defect.

The notices issued Friday added eight additional countries or territories to the list, bringing the total to 22. The warnings are spread throughout the globe and include places in South America, the Caribbean, Central America, Polynesia and more.

Travelers heading to those areas are asked to “practice enhanced precautions” to prevent mosquito bites, which is how the virus is spread. Pregnant women are advised to rethink their travel plans because of Zika’s potential impact on their unborn children.

Last week, the Hawaii Department of Health announced a child born with microcephaly — a birth defect marked by a smaller-than-usual head — had previously been infected with Zika. The department said his mother likely contracted the virus when she was living in Brazil last May.

The Brazilian Ministry of Health reports that there have been 3,893 cases of microcephaly in the country since the virus arrived in May. The country used to see fewer than 200 cases per year.

Children with microcephaly can develop seizures, vision problems and have developmental delays, the CDC says, but it only occurs in 2 to 12 out of every 10,000 births in the United States.

Scientists are still trying to find a conclusive link between Zika and microcephaly, which can be caused by several other factors. Last week, Dr. Lyle Petersen, the director of CDC’s division of vector-borne diseases, told a news briefing the CDC had “the strongest scientific evidence to date” of a link between Zika and “poor pregnancy outcomes,” though more tests were needed.

Still, the warnings and advice for pregnant women continue. Earlier this week, the CDC issued new guidelines about how healthcare providers in the United States should care for pregnant women who had traveled or were planning to travel to areas where Zika was being transmitted.

Only about 1 in 5 people infected with the virus display any signs of illness, the CDC says, and symptoms are generally mild. They include fever, rash and joint pain, and most people recover within a week. The illness is seldom severe and rarely requires hospitalization.

There haven’t been any reports of people contracting the virus in the United States, the CDC says, though there have been some instances where travelers got bit by infected mosquitos overseas and returned home. The mosquitos that transmit Zika are found in the United States, though Dr. Petersen told the news briefing it’s unclear exactly how or if the virus may spread here.

He told reporters the country has seen improvements in anti-mosquito measures, like using air conditioning and window and door screens, which have helped reduce the spread of other mosquito-borne illnesses, like dengue and malaria, in the past. The CDC encourages all travelers to Zika-prone areas to sleep in screened or air-conditioned rooms, as well as wear long clothing and insect repellant, as there is no vaccine or medicine that can currently prevent an infection.

Countries and territories where the CDC has issued travel notices for Zika include Bolivia, Brazil, Colombia, Ecuador, French Guiana, Guyana, Paraguay, Suriname, Venezuela, Barbados, Guadeloupe, Haiti, Martinique, Saint Martin, Samoa, Cape Verde, El Salvador, Guatemala, Honduras, Panama, Mexico and Puerto Rico.

CDC issues guidelines for pregnant women during Zika outbreak

CHICAGO (Reuters) – The U.S. Centers for Disease Control and Prevention on Tuesday issued guidelines for doctors caring for pregnant women during the Zika outbreak, a mosquito-borne illness linked with microcephaly marked by unusually small head size and brain damage.

The new guidelines urge doctors to ask their pregnant patients about their travel history to areas with Zika virus transmission.

Women who had traveled to regions in which Zika virus is active and who report symptoms during or within two weeks of travel should be offered a test for Zika virus infection. Pregnant women who had no clinical symptoms associated with the infection such be offered an ultrasound to check the fetus’ head size or check for calcium, two signs of microcephaly.

(Reporting by Julie Steenhuysen, editing by G Crosse)

Hawaiian child born with birth defect was infected with Zika virus

A Hawaiian child who was recently born with a rare birth defect called microcephaly had been infected with the mosquito-borne Zika virus, the state Department of Health announced.

Officials made the announcement on Friday, the same day the Centers for Disease Control and Prevention (CDC) issued updated travel warnings for regions where Zika outbreaks are present.

The Zika virus usually only causes a mild illness and most people typically recover in a week, the CDC says, but the virus is collecting global attention because scientists are currently working to see if it is responsible for causing birth defects such as the one found in the Hawaiian child.

According to the CDC, children born with microcephaly have smaller-than-usual heads, and the defect may lead to other issues such as seizures, developmental delays and vision problems.

The Brazilian Ministry of Health reported a significant rise in the birth defect since the virus arrived in May. The country used to see fewer than 200 cases per year, but now has about 3,500.

The Hawaiian baby’s mother was living in Brazil last May, the state Department of Health said in a news release, and likely transmitted the virus to her child while he or she was in the womb.

Microcephaly can be caused by a variety of issues including genetic changes, malnutrition, alcohol exposure and certain kinds of infections, according to the CDC, but it’s still a relatively rare defect and only surfaces in about 2-12 babies out of every 10,000 born in the United States.

“We are saddened by the events that have affected this mother and her newborn,” Hawaii Department of Health State Epidemiologist Sarah Park said in a statement.

Hawaii health officials said neither the mother nor the child are currently at risk of transmitting Zika, nor were they ever at risk of spreading the virus throughout Hawaii. The country has yet to see a locally contracted case of Zika, the CDC has said.

However, the Hawaii Department of Health reported six people have gotten infected while visiting foreign countries and returned to the state.

The CDC on Friday sent out updated travel notices for Puerto Rico, Mexico, Central America, South America and the Caribbean, where Zika is found in local mosquitos, asking travelers — especially pregnant women — to “practice enhanced precautions” to prevent mosquito bites. Previously, the CDC had only been asking travelers to “practice usual precautions.”

There isn’t any vaccine against a Zika infection, the CDC says.

“The virus is spreading fairly rapidly throughout the Americas,” Dr. Lyle Petersen, the director of CDC’s division of vector-borne diseases, told reporters during a Friday evening news briefing, according to a transcript posted on the CDC’s website. “We know in populations that it does affect, a large percentage of the population may be become infected. And because of this growing risk of or growing evidence that there’s a link between Zika virus and microcephaly, which is a very severe and devastating outcome, it was important to warn people as soon as possible.”

Petersen told the news briefing that the CDC recently found its “strongest scientific evidence to date” of a link between Zika and “poor pregnancy outcomes” like microcephaly, but more tests and studies were needed to determine the risks the Zika virus may pose to pregnant women.

Common symptoms of Zika include fever, joint pain and rash, the CDC says. However, Petersen told the news briefing that only 1 in 5 people infected with the virus will display those symptoms.

Petersen also told reporters there have been at least eight United States travelers who tested positive for Zika after traveling overseas in the past 15 months, compared to just 12 who tested positive for the virus between 2007 and 2014. And the CDC is also still receiving samples from people displaying symptoms, so that number could increase as more test results come back.

While the specific kind of mosquito that transmit the virus are present in parts of the United States, Petersen told reporters that improvements in housing construction, air conditioning and mosquito control have helped prevent large outbreaks of other mosquito-borne illnesses.

He told the news briefing it would be difficult to determine exactly how Zika may spread in the coming months.

“I think we’re just going to have to wait to see how this all plays out,” he told reporters. “These viruses certainly can spread in populations for some time. But, again, this is new. This is a dynamic and changing situation. I think it’s really impossible for us to speculate what may happen in three or four or even next month for that matter.”

Separately, Hawaii is dealing with another outbreak of a mosquito-borne illness.

The state Department of Health says there have been 223 cases of dengue fever since Sept. 11. It’s the first locally-acquired outbreak of the disease since 2011.

The World Health Organization says dengue, which can cause fevers, headaches, muscle and joint pains and rashes, has become increasingly common in the past 50 years — spreading to more than 100 countries and placing about half the world’s population at risk of an infection.

Zika virus confirmed in Texas traveler, health officials say

Health officials in one Texas county say they’ve received word that a traveler who recently visited Latin America contracted the Zika virus, a puzzling mosquito-borne illness that has collected lots of attention because it may be linked to a substantial rise in birth defects in Brazil.

Harris County Public Health & Environmental Services made the announcement Monday, saying the Centers for Disease Control and Prevention (CDC) confirmed the diagnosis.

Harris County encompasses Houston and is one of the country’s largest counties.

According to the CDC, the Zika virus is spread when an infected mosquito bites a person, usually triggering a mild illness that causes people to experience symptoms like fever, rashes and joint pain. Most people recover within a week, and there’s seldom any need for hospitalization.

However, the Brazilian Ministry of Health is currently investigating more than 3,000 cases of microcephaly, a disorder that causes children to be born with abnormally small heads. Brazil only saw 147 cases of microcephaly last year, but the numbers have surged since the Zika virus arrived in May and authorities are still working to see if there’s a direct link between the two.

The CDC has said there hasn’t been any indication Zika has been contracted in the United States, though there have been multiple cases of people getting infected while visiting a foreign country and returning home. Officials didn’t indicate when or where this traveler got infected.

The virus has caused outbreaks in at least 12 countries in North and South America, according to the CDC, as well as many others in Africa and Southeast Asia. In late December, the CDC issued a travel notice for Puerto Rico after the island identified its first locally-acquired Zika infection.

The CDC asks people traveling to Puerto Rico — and other countries where Zika is present — to take proactive steps to safeguard themselves from mosquito bites, like wearing insect repellant and wearing long sleeves and pants. But the organization says the virus will likely continue to reach new territories because the specific kind of mosquitos that spread it live across the globe.

That type of mosquito — the Aedes species — are present in Harris County, according to the county Public Health & Environmental Service’s website. The agency echoed the CDC’s calls for travelers to take preventative steps when they’re traveling to nations where Zika is found.

There’s currently no vaccine against the virus, the CDC says.