Tag Archives: Mosquito

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)

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.

CDC Issues Travel Notice After Zika Virus Arrives in Puerto Rico

Health officials are warning would-be travelers about the spread of a mosquito-borne illness that might be causing a growing number of children to be born with smaller-than-usual heads.

Late last week, the Centers for Disease Control and Prevention (CDC) issued a travel notice for Puerto Rico after the island reported its first locally contracted case of the virus. The advisory encourages travelers to take proactive steps to prevent mosquito bites, like wearing insect repellant and long clothing. The CDC has issued similar warnings for Mexico, Central America and South America, as several other countries have said the virus has sickened humans there.

Zika often causes people to experience fever, joint pain, rashes and red eyes for up to a week, the CDC says, but the illness seldom results in hospitalization. However, the Brazilian Ministry of Health recently said it was investigating about 3,000 cases of microcephaly, a neurological disorder in which children are born with unusually small heads and underdeveloped brains.

Before this year, the ministry said it usually saw about 150-170 annual cases of microcephaly. But since the Zika virus arrived in May, the ministry said the number of suspected cases have surged to 2,975. Authorities are currently examining if there’s a conclusive link between the two.

The CDC said test results have shown that some Brazilian babies with microcephaly were infected with Zika, but other babies developed microcephaly and tested negative for the virus. There are other possible causes for the defect, so it will take some time to determine the culprit. Still, the CDC says woman who are pregnant should be extra careful to prevent mosquito bites.

There isn’t any vaccine that can prevent the virus or any medicine that can treat it, according to the CDC. Because the mosquitos that transmit Zika live all across the planet, the organization says it’s likely that the virus could spread to new regions where illnesses have yet to be reported.

The virus can remain in the bloodstreams of infected individuals for about a week, according to the CDC, during which time it’s extra important to avoid mosquito bites to prevent transmission. While the organization reports no one has acquired Zika in the United States, there has been at least one instance where a traveler got sick while visiting a foreign country and returned home.

Hawaii Reports Additional Cases of Dengue Fever

The number of people infected with dengue fever in Hawaii is climbing, officials said Monday.

The Hawaii Department of Health reported that it was investigating 167 total cases of the mosquito-borne illness, which can lead to fatal consequences in extreme cases. There were 122 confirmed dengue cases as of Dec. 2, signifying 45 additional infections in about three weeks.

State health officials said only three of the 167 cases are currently infectious. The other people got sick between Sept. 11 and Dec. 10, so they are no longer at risk of transmitting the disease.

The health department also reported there were 659 additional potential dengue infections that had been ruled out, either through test results or the illnesses failing to meet the case criteria.

Dengue isn’t endemic (regularly found) in Hawaii, though health officials said it can occasionally be brought in from travelers who got infected in endemic regions. But this latest outbreak on the Big Island is unique because it’s the first cluster of locally acquired cases since 2011, when Centers for Disease Control and Prevention (CDC) records indicate five people got sick in Oahu.

According to the World Health Organization (WHO), an arm of the United Nations, dengue is transmitted when an infected mosquito bites a human. The infection generates a flu-like illness — from which most people usually recover within a week — though it sometimes progresses to severe dengue. In those instances, people can suffer organ impairment and severe bleeding.

The WHO estimates severe dengue hospitalizes about 500,000 people per year, and about 2.5 percent of them die. Dengue is much more common, with some estimates indicating as many as 136 million people falling ill every year, but non-severe cases of the disease are rarely ever fatal. Symptoms can include severe headaches, swollen glands, joint and muscle pain and a high fever.

The Hawaii outbreak reflects a global trend in which dengue is spreading to new locales.

The WHO reports the disease was traditionally found in the tropics and subtropics, but it’s now endemic in more than 100 countries and about half the world’s population is at risk of infection. Still, early detection and access to good medical care keeps the mortality rate below 1 percent. Without those, the WHO says severe dengue can be fatal in more than 20 percent of cases.

Hawaii health officials say it’s still safe to visit the island. The department encourages travelers to use insect repellant and wear long sleeves and pants to help prevent mosquitos from biting.