U.S. life expectancy fell in 2016 as opioid overdoses surged: CDC

A used container of the drug Narcan used against opioid overdoses lies on the ground in a park in the Kensington section of Philadelphia, Pennsylvania, U.S. October 26, 2017. REUTERS/Charles Mostoller

NEW YORK (Reuters) – Life expectancy in the United States dipped in 2016 as the number of deaths due to opioid drug overdoses surged and total drug overdose deaths rose 21 percent to 63,600, the U.S. Centers for Disease Control and Prevention said on Thursday.

Life expectancy fell to 78.6 years, a decrease of 0.1 year from 2015, the second annual decline in a row and the first two-year decline since a drop in 1962 and 1963.

Opioid-related overdose deaths have been on the rise since 1999, but surged from 2014 to 2016, with an average annual increase of 18 percent, to become a national epidemic. From 2006 to 2014 the rise was only 3 percent annually on average and between 1999 to 2006 averaged 10 percent per year.

In 2016, 42,249 people died from opioid-related overdoses, up 28 percent from 2015, while the number of deaths from synthetic opioids other than methadone, such as fentanyl and tramadol, more than doubled to 19,413, the CDC said.

The 2016 rate of overdose deaths was up across all age groups but was highest rate among people aged 25 to 54.

West Virginia, Ohio, New Hampshire, the District of Columbia and Pennsylvania had the highest age-adjusted drug overdose death rates in 2016.

The number of drug overdose deaths involving natural and semisynthetic opioids, which include drugs like oxycodone and hydrocodone, was 14,487 in 2016.

As the U.S. opioid addiction epidemic has worsened, many state attorneys general have sued makers of these drugs as they investigate whether manufacturers and distributors engaged in unlawful marketing behavior.

President Donald Trump in October declared the opioid crisis a public health emergency, which senior administration officials said would redirect federal resources and loosen regulations to combat abuse of the drugs. However, he stopped short of declaring a national emergency he had promised months before, which would have freed up more federal money.

(Reporting by Caroline Humer; editing by Lisa Von Ahn and Jonathan Oatis)

Opioid abuse crisis takes heavy toll on U.S. veterans

Needles used for shooting heroin and other opioids along with other paraphernalia litter the ground in a park in the Kensington section of Philadelphia, Pennsylvania, U.S. October 26, 2017.

By Barbara Goldberg

NEW YORK (Reuters) – Opioid drug abuse has killed more Americans than the Iraq, Afghanistan and Vietnam wars combined, and U.S. veterans and advocates this Veteran’s Day are focusing on how to help victims of the crisis.

Veterans are twice as likely as non-veterans to die from accidental overdoses of the highly addictive painkillers, a rate that reflects high levels of chronic pain among vets, particularly those who served in the wars in Iraq and Afghanistan, according to federal data.

U.S. government and healthcare officials have been struggling to stem the epidemic of overdoses, which killed more than 64,000 Americans in the 12 months ending last January alone, a 21 percent increase over the previous year, according to the Centers for Disease Control. About 65,000 Americans died in Vietnam, Iraq and Afghanistan.

President Donald Trump named opioids a national public health emergency and a White House commission last week recommended establishing a nationwide system of drug courts and easier access to alternatives to opioids for people in pain.

“Our veterans deserve better than polished sound bites and empty promises,” said former Democratic Congressman Patrick Kennedy, a recovering addict and a member of the president’s opioid commission.

Kennedy said in an e-mail that more funding was needed for treatment facilities and medical professionals to help tackle the problem.

One effort to address the issue has stalled in Congress – the proposed Veterans Overmedication Prevention Act, sponsored by Senator John McCain. That measure is aimed at researching ways to help Veterans Administration doctors rely less on opioids in treating chronic pain.

“The Veterans Administration needs to understand whether overmedication of drugs, such as opioid pain-killers, is a contributing factor in suicide-related deaths,” McCain, one of the nation’s most visible veterans, said in an e-mail on Thursday. He noted that 20 veterans take their lives each day, a suicide rate 21 percent higher than for other U.S. adults.

The VA system has stepped up its efforts to address the crisis, having treated some 68,000 veterans for opioid addiction since March, said Department of Veterans Affairs spokesman Curtis Cashour.

The department’s Louis Stokes VA Center in Cleveland has also begun testing alternative treatments, including acupuncture and yoga, to reduce use of and dependency on the drugs, the VA said.

A delay in naming a Trump administration “drug czar” to head the effort, however, has fueled doubts about immediate action on the opioid crisis. Last month the White House nominee, Representative Tom Marino, withdrew from consideration following a report he spearheaded a bill that hurt the government’s ability to crack down on opioid makers.


(Reporting by Barbara Goldberg; Editing by Dan Grebler)


CDC director calls Zika in Puerto Rico a ‘challenge and crisis’

SAN JUAN, PUERTO RICO (Reuters) – During a tour of Zika preparations in Puerto Rico, Dr. Thomas Frieden, director of the U.S. Centers for Disease Control and Prevention, called Zika a “tremendous challenge and crisis” and said protecting pregnant women from the virus is a top priority.

In Brazil, Zika has been linked to a spike in cases of microcephaly, a birth defect marked by small head size and underdeveloped brains.

“Until a few months ago, no one had any idea that Zika could cause birth defects,” Frieden told reporters Tuesday at a briefing in Puerto Rico’s health department.

Frieden has been working with CDC staff and the Puerto Rican government on strategies to protect pregnant from becoming infected with the mosquito-borne virus, which Frieden called a top priority.

In Puerto Rico, the Aedes aegypti mosquito that carries Zika is widespread, and Frieden said controlling it will require a multi-pronged approach involving government, municipalities, neighbors, families and society at large.

Cases of Zika are doubling weekly in Puerto Rico, and the CDC expects hundreds of thousands of individuals will become infected, including thousands of pregnant women.

To protect pregnant women, Frieden recommended using insect repellent daily and reliably.

He also suggested adding window screens and air conditioning, where possible. And he called for reducing standing water in and around homes to eliminate mosquito breeding habitats.

Frieden’s comments, delivered mostly in Spanish, followed two days of briefings with staff at the CDC’s Emergency Operations Center in San Juan. CDC researchers are monitoring the outbreak and studying the best ways to prevent Zika infections through education campaigns, and the distribution of Zika prevention kits for pregnant women.

Much remains unknown about Zika, including whether the virus actually causes microcephaly in babies. Brazil said it has confirmed more than 640 cases of microcephaly, and considers most of them to be related to Zika infections in the mothers. Brazil is investigating more than 4,200 additional suspected cases of microcephaly.

At the CDC’s Dengue Branch in Puerto Rico, scientists are conducting research on the most effective mosquito control measures, and processing diagnostic tests from blood samples delivered daily to the laboratory.

Dr. Jorge Munoz, branch director, said in an interview they are capable of processing 400 to 500 blood samples a week. Scientists at the laboratory developed a triple test that can detect Zika, dengue and chikungunya – three different viruses carried by the Aedes aegypti mosquito that is endemic in Puerto Rico.

The test will be crucial in helping to quickly sort out whether Zika was the cause of an infection or whether it was dengue and chikungunya, which also cause infection and illness.

“Puerto Rico is in a very different situation from the rest of the United States,” Frieden told the briefing.

Besides the high density of Aedes aegypti mosquitoes, Puerto Rico has a lot of housing without window screens or air conditioning.

“The combination of those two things, when you add Zika in, means the likelihood of a very large number of cases,” Frieden said.

“In rest of the United States, we may see clusters,” he said. But if Zika behaves the way chikungunya and dengue have, “we will not see widespread transmission.”

(Reporting by Julie Steenhuysen; Editing by Bernard Orr)

Oregon to release soil test results in pollution scare this week

PORTLAND, Ore. (Reuters) – Oregon officials this week will release test results on soil from neighborhoods near two Portland glass factories accused of spewing toxic metals into the air for years, a revelation that has led to a class-action suit and demands for more oversight.

The results of the testing could heighten suspicions from residents and environmental advocates that emissions of arsenic and cadmium from the two plants exposed residents to much higher levels of the heavy metals than have been told.

Miriam Rotkin-Ellman, a public health scientist with the Natural Resources Defense Council, said the scare demonstrates the need for closer federal oversight.

“Communities are left testing their soil, testing their children, testing their homes and saying, well, how come I see these contaminations?” she said. “That’s not how it should be.”

There is already ample evidence from tests conducted by the U.S. Forest Service of airborne contamination near the factories, as well as signs that the metals may have settled into the soil.

The Forest Service tests, conducted on moss growing on trees near one of the factories, found levels of arsenic 150 times higher and cadmium 50 times higher than Oregon safety benchmarks. Near the second factory, cadmium levels were found to be similarly elevated.

Long-term arsenic exposure is linked to skin cancer and cancers of the lung, bladder, and liver as well as skin color changes and nerve damage, according to information posted on the Oregon Health Authority website. Long-term cadmium exposure is linked to lung and prostate cancer, as well as kidney disease and fragile bones, according to the site.

The state has not received any reports of people being treated or hospitalized as a result of exposure to the metals released in emissions by the glass companies, according to Jonathan Modie, a spokesman for the Oregon Health Authority.

U.S. Senator Ron Wyden of Oregon, who lives near one of the hot spots, describes the situation in the state’s largest city as a public health emergency. He told Reuters on Friday that he had asked the Centers for Disease Control and the Environmental Protection Agency to provide “experts on the ground” when the soil tests are released to “help us get at the core facts.”

This comes after revelations in Flint, Michigan, that a switch in the city’s water source to save money corroded its aging pipes and released lead and other toxins into its drinking water. That crisis has emerged as a rallying point for Democrats as the U.S. presidential election approaches.

Even if the soil tests in Portland show low levels of the heavy metals, residents who live near the factories fear the exposure may be more widespread, extending beyond the hot spots that are being tested.

“This is just the tip of the iceberg,” said Kerry Ryan, a Portland resident who lives five blocks from one of the factories.

Ryan, who now has an 11-month-old daughter whom she is breastfeeding, said she is arranging to have herself tested for exposure to the metals.

According to the Oregon Health Authority’s website Q&A, arsenic and cadmium can be found in breast milk and may contribute to low birth weight.

Bullseye Glass Co officials did not return a call seeking comment. Officials with Uroboros Glass Studio declined to comment.

Last month, Oregon public health officials advised residents to stop eating vegetables grown in gardens within a half mile of the so-called pollution “hot spots,” or areas where the pollution appears to be concentrated.

On Thursday, about 50 residents mounted a protest in downtown Portland, chanting “clean air now” and delivering boxes of rotting produce harvested from their gardens to the state’s environmental quality offices.

Arsenic and cadmium contamination, confirmed by the Oregon Department of Environmental Quality, occurred near Bullseye Glass, located in a middle-class neighborhood near public schools and a city park.

Cadmium contamination was confirmed near Uroboros Glass, located in an industrial section of a residential neighborhood near the Willamette River.

Both plants have voluntarily halted the use of the metals, used to create color for stained glass, according to the state’s Department of Environmental Quality, which is conducting the soil tests that are set for release this week at the request of Gov. Kate Brown

Last week attorneys for seven residents filed a class action lawsuit against Bullseye, alleging the company was negligent and reckless in burning heavy metals without adequate pollution controls.

Bullseye was in compliance with state regulations under a loophole that Wyden called “the size of a lunar crater” during a press conference in February.

According to the Portland Oregonian newspaper, the firm Weitz & Luxenberg is also meeting with area residents. The firm is currently working with environmental activist Erin Brockovich to seek redress for residents whose health may have been harmed by a massive natural gas leak in Southern California.

(Additional reporting by Eric Johnson; Editing by Sara Catania, Steve Gorman and Diane Craft)

Zika response in focus with new evidence of birth defect link

GENEVA/WASHINGTON (Reuters) – Evidence mounted on Friday linking Zika to the birth defect microcephaly, and the U.N. health agency set a review of travel advice related to the outbreak of the virus while U.S. officials planned strategy to control the mosquitoes that spread it.

The virus is capable of rapidly infecting and harming developing fetal brain cells, scientists said in a study that provided insight into how the virus might cause microcephaly in fetuses.

The researchers said the study, published on Friday in the journal Cell Stem Cell, does not prove a direct causal link between Zika and microcephaly in newborns, a condition defined by unusually small heads that can result in developmental problems. But they said it does identify where the virus may be inflicting the most damage in developing fetuses.

Zika has been linked to numerous cases of microcephaly in Brazil, where the current outbreak began. The virus is spreading rapidly in Latin America and in Caribbean nations, prompting the World Health Organization last month to declare a global public health emergency.

The WHO on Friday said there is accumulating evidence of a link between the virus and microcephaly as well as a rare disorder called Guillain-Barre syndrome in which the immune system attacks part of the nervous system.

The WHO’s Emergency Committee will meet Tuesday to review “evolving information” and its recommendations on travel, trade and mosquito control in what is thought to be high season for transmission of the virus in the southern hemisphere.

The WHO last month advised pregnant women to consider delaying travel to areas where Zika is spreading.

Travel to Brazil has been a particular concern because the Summer Olympics will be held in Rio de Janeiro in August.

Dr. Bruce Aylward, WHO’s executive director for outbreaks and health emergencies, said recently published studies in the Lancet medical journal on microcephaly and by the U.S. Centers for Disease Control and Prevention (CDC) on Guillain-Barre had strengthened the case that Zika is responsible.

The White House and the CDC will bring together U.S. state and local officials on April 1 for a summit at the CDC’s Atlanta headquarters to urgently craft a plan to attack the hard-to-control mosquito that spreads the virus.

The White House is inviting officials involved in mosquito control and public health to discuss how best to track and control the spread of the virus and respond when people are infected.

U.S. federal health officials expect the first locally transmitted cases of the Zika virus in the continental United States by June or July.

“We can’t say for sure that we’re not going to have a major outbreak in the United States. I do not think we will, but we will be prepared for it anyway,” Dr. Anthony Fauci, director of the U.S. National Institute of Allergy and Infectious Diseases, said at an event presented by the Harvard T.H. Chan School of Public Health in collaboration with Reuters.


There were fresh signs on Friday of Zika-linked microcephaly cases outside Brazil. The first microcephaly case linked to Zika was reported in Colombia.

In addition, doctors in Venezuela reported their first suspected Zika-linked microcephaly case in a fetus that died whose mother likely was infected with the virus.

Much remains unknown about Zika, including whether the virus actually causes microcephaly. Brazil said it has confirmed more than 640 microcephaly cases and considers most to be related to Zika infections in the mothers. Brazil is investigating more than 4,200 additional suspected microcephaly cases.

The study in Cell Stem Cell showed that Zika infects a kind of neural stem cell that gives rise to the cerebral cortex, the brain’s outer layer responsible for intellectual capabilities and higher mental functions.

These cells, exposed to the virus in laboratory dishes, became infected within three days, turned into “virus factories” for viral replication and died more quickly than normal, the researchers said.

Florida State University researcher Hengli Tang, the study’s lead author, told Reuters the study suggests the virus would be capable of doing the damage seen in microcephaly.

French scientists, in a retrospective study of a 2013-2014 Zika outbreak in French Polynesia, said last week they had proved a link between Zika and Guillain-Barre, suggesting countries hit by the Zika outbreak will see a rise in the neurological condition.

“The important thing is the data is moving in one direction. And that’s the reason we’ve asked the Emergency Committee again next week to convene and look at these data,” the WHO’s Aylward said, referring to a group of independent experts chaired by David Heymann.

(Reporting by Stephanie Nebehay in Geneva and Roberta Rampton in Washington; Additional reporting by Andrew M. Seaman and Bill Berkrot in New York, Alexandra Ulmer and Corina Pons in Caracas and Julia Symmes Cobb in Bogota; Writing by Will Dunham; Editing by Michele Gershberg and Leslie Adler)

Hawaii County declares state of emergency over dengue fever outbreak

The growing number of dengue fever cases in Hawaii County has prompted the county’s mayor to declare a state of emergency, a measure that aims to reduce the spread of the disease.

William P. Kenoi issued the declaration on Monday as the state Department of Health reported that there have been confirmed 251 cases of the mosquito-borne illness since last September.

All of the confirmed cases have been in Hawaii County, which is the state’s largest island.

Kenoi’s declaration allows people to dump tires at county landfills, which had been outlawed. The Centers for Disease Control and Prevention (CDC) says used tires can collect rain, making them a good place for mosquitos to lay eggs, and mosquito control is key to combating dengue.

Hawaii Governor David Y. Ige issued a statement saying he supported Kenoi’s emergency proclamation, but he would only declare a statewide emergency if certain conditions were met.

According to the World Health Organization (WHO), dengue fever usually triggers a flu-like illness that lasts up to a week. Symptoms include headaches, vomiting, muscle pains and rashes. In some cases, however, dengue can become severe and lead to potentially fatal complications.

The WHO says severe dengue causes about 500,000 hospitalizations and 12,500 deaths every year, though access to proper medical care significantly lowers the disease’s mortality rate.

Hawaii health officials have not reported any deaths as a result of this outbreak.

The Hawaii Department of Health says dengue isn’t usually found in Hawaii, but there have been some cases of infected travelers coming to Hawaii from areas where the disease is spread. But it says this outbreak is of locally-acquired dengue, the state’s first such event since 2011.

Dengue is different than the Zika virus, another mosquito-borne illness. However, both dengue and Zika can be transmitted by the Aedes aegypti mosquito and both have spread to new areas.

The WHO says dengue has reached more than 100 countries over the past 50 years, recording a 30-fold increase in its incidence. About half the world’s population is now at risk of infection.

The CDC has issued numerous travel warnings about the Zika virus, and the WHO recently deemed Zika an international public health concern as scientists investigate its potential connection to a rare birth defect called microcephaly that affects head size.

The Hawaii Department of Health has said that one Oahu child who was born with microcephaly had been infected with Zika, though his mother likely got infected when she was living in Brazil. The country saw a substantial rise in microcephaly last year.

Only about 20 percent of those infected with Zika show any symptoms, according to the CDC. Those symptoms include fever, rash and joint pain and most people fully recover within a week.

Chipotle E. Coli outbreaks appear to be over, CDC says

Two E. Coli outbreaks linked to Chipotle restaurants appear to be over, officials said Monday.

The Centers for Disease Control and Prevention (CDC) said it still doesn’t know what specific ingredient was behind the outbreaks, though it hasn’t received word of any illnesses since Dec. 1.

The CDC said 60 people in 14 states fell ill last October and November, and 22 were hospitalized. The organization interviewed 59 of those people, and 52 of them said they had eaten at Chipotle.

The CDC collected food from several Chipotle restaurants, though none of its tests showed signs of the bacteria. The organization said a food source is only identified in 46 percent of outbreaks, and it can be hard to determine the exact item responsible for the illnesses in cases where restaurants cook several ingredients together and serve them in different menu items.

According to the CDC, the first E. Coli outbreak affected 55 people in Washington, Oregon, California, Delaware, Illinois, Kentucky, Maryland, Minnesota, New York Ohio and Pennsylvania. The second outbreak, which featured a different strain of the bacteria, sickened five people in Kansas, Oklahoma and North Dakota. None of the 60 people died or developed hemolytic uremic syndrome, a type of kidney failure that sometimes occurs following E. Coli infections.

Chipotle has said it has since implemented new food safety protocols, and announced earlier this month that it will close all of its restaurants for four hours on Feb. 8 for a food safety meeting.

The outbreaks were just a part of the recent struggles for Chipotle.

The restaurant also told investors earlier this month that it was subpoenaed by a federal grand jury in connection with an “isolated norovirus incident” in August at a California restaurant. The same message indicated a norovirus outbreak in December at a Boston restaurant “worsened the adverse financial and operating impacts” Chipotle experienced from the E. Coli outbreaks.

Norovirus and E. Coli are both foodborne illnesses that can cause vomiting, diarrhea and stomach cramps, according to the CDC.

Chipotle’s stock was trading at $750.42 on Oct. 13, near an all-time high, but tumbled to $404.26 on Jan. 12 amid the E. Coli and norovirus concerns. That was a 54 percent drop.

The stock has rebounded slightly and was trading at $472.64 on Monday afternoon.

CDC has new questions about 39-state salmonella outbreak

Health officials have new questions about a deadly salmonella outbreak that has sickened nearly 900 people nationwide, the Centers for Disease Control and Prevention (CDC) said this week.

Since the beginning of July, the CDC says 888 people in 39 states have been affected by the outbreak, which has been blamed on contaminated cucumbers that were imported from Mexico.

The outbreak has killed at least four people and sent 191 people to the hospital, the CDC said.

After an investigation, Andrew & Williamson Fresh Produce and Custom Produce Sales each initiated cucumber recalls in the first half of September as a result of possible contamination.

However, the CDC’s latest update on the outbreak said 106 people have fallen ill after Sept. 24, when all of the recalled cucumbers should have been either off the shelves or spoiled. That includes 50 people who have gotten sick since Nov. 19, when the CDC last issued an update.

The CDC said an investigation into the new illnesses is ongoing, and officials are trying to determine if cross-contamination from the recalled cucumbers could be to blame.

The organization is encouraging anyone who might have bought or sold recalled cucumbers to wash and sanitize drawers, shelves, crates or reusable grocery bags where the vegetables were stored.

The CDC has not yet determined any other food item that could be causing people to get sick.

Illnesses have been reported in every state except Maine, Massachusetts, Rhode Island, Vermont, New Jersey, Delaware, Michigan, West Virginia, North Carolina, Georgia and Mississippi.

While the rate of reported illnesses has dropped since the recalls were issued, the CDC says it’s still above what is expected for this time of year. And the latest update indicated one person got sick in Tennessee, a state that had not previously reported any illnesses tied to the outbreak.

Salmonella usually triggers a mild illness that can cause fever, diarrhea and abdominal cramps, the CDC says, and most people recover within a week without any treatment. But children, older adults and those with weak immune symptoms are particularly at risk of severe infections.

According to the CDC, an estimated 1.2 million people in the United States get sick from salmonella every year. About 19,000 of them are hospitalized and about 450 of them die.

California has reported the most illnesses tied to this outbreak, with 241 people getting sick there. The CDC said that three of them died, though salmonella likely wasn’t a factor in two cases. The outbreak is also being blamed for one death apiece in Arizona, Oklahoma and Texas.

Dole recalls packaged salads after multi-state listeria outbreak

Dole is temporarily shutting down one of its production facilities and recalling all of the salads that were made there because the facility has been linked to a multi-state outbreak of listeria.

The recall notice was posted on the Food and Drug Administration website on Friday.

The Centers for Disease Control and Prevention (CDC), which has been investigating the outbreak, said 12 people in six states have been hospitalized since July. One person died.

The CDC determined that salads produced and packaged at Dole’s facility in Springfield, Ohio, were likely behind the illnesses. Dole initiated the recall and decided to temporarily suspend production at the facility “out of an abundance of caution,” according to the recall notice.

The salads in question were sold under a variety of different brand names — including Dole, Fresh Selections, Simple Truth, Marketside, The Little Salad Bar and President’s Choice, the CDC said. However, they all have the letter ‘A’ at the beginning of a product code that appears on the upper-right-hand corner of the package, according to Dole’s recall notice.

Dole said none of its other products or facilities are affected by the recall, and added that packaged salads that have ‘B’ or ‘N’ at the start of their product codes aren’t being recalled. Those salads were produced at different facilities, and the CDC added that it doesn’t currently have any evidence suggesting those salads are linked to the outbreak.

Dole said the recalled salads were sold in Alabama, Connecticut, Florida, Georgia, Illinois, Indiana, Kentucky, Louisiana, Michigan, Massachusetts, Maryland, Minnesota, Missouri, Mississippi, North Carolina, New Jersey, New York, Ohio, Pennsylvania, South Carolina, Tennessee, Virginia and Wisconsin, as well as the Canadian provinces of Ontario, New Brunswick and Quebec.

The company encouraged consumers and stores who still have packaged salads with product codes beginning with ‘A’ to throw them out without eating them.

According to the CDC, listeria is a bacteria that can lead to listeriosis, a rare but life-threatening condition that is often contracted by eating contaminated food. The organization estimates that listeriosis sickens about 1,600 people annually in the United States, killing about 260 of them.

Newborns, older adults people with weak immune systems and pregnant women are generally at risk, the CDC says, and the bacteria can lead to miscarriages or stillbirths. Common symptoms include fever and muscle aches, though the disease can also cause convulsions in certain people.

This particular outbreak sickened people in Michigan, Indiana, Pennsylvania, New York, New Jersey and Massachusetts, according to the CDC, and killed a person from Michigan.

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.