Delta Blood Bank imposes donor restrictions to prevent Zika virus contamination

Delta Blood Bank has established a one-month waiting period for donors who have recently traveled to a region affected by the Zika virus, a policy aimed at preventing contamination of blood supplies.

Joan Baker, executive director of Delta, said the blood bank is following a national recommendation. Donors in the northern San Joaquin Valley are asked to wait 28 days before donating blood if they have traveled to places where Zika has spread, including Mexico, countries in Central and South America and the Caribbean.

That’s 28 days from the time they returned to the United States, Baker said.

It is one of the precautions as local agencies prepare for the mosquito-borne virus that has rapidly spread since outbreaks in Brazil last May. Mosquitoes have transmitted the Zika virus in the U.S. territories of Puerto Rico, the Virgin Islands and Samoa, and 52 cases have been reported in the United States among people who had returned from travel outside the country, according to the Centers for Disease Control and Prevention.

Stanislaus County public health has issued advisories to caution pregnant women from the Valley about travel to affected countries. Pregnant women are the major concern because the infection can cause a severe birth defect called microcephaly, in which the baby’s brain and head are not fully developed.

Delta, based in Stockton, accepts blood donations in Modesto, Ceres, Turlock, Sonora, Manteca and other cities.

It has routinely asked donors about travel on its screening questionnaire and is posting signs and information about the Zika-related waiting period, Baker said. Others who have not recently traveled to the affected countries are welcome to donate.

Baker said that 28 days is double the normal time it takes for the Zika virus to be eliminated from the bloodstream. Health experts are not sure how readily the virus can be transmitted to a person through a blood transfusion.

Two cases of Zika infection through blood transfusions have been confirmed, but it did not happen in the United States, Baker said.

Delta hopes the waiting period does not cause a significant drop in blood donations. “Over the holidays, people do travel to Mexico and South America, and spring break is coming up, so we could have additional deferrals because of the travel,” Baker said.

The director said the blood can be discarded if recent donors say they neglected to report a trip to an affected region. The recommendation for the 28-day deferral came from the American Association of Blood Banks. The Food and Drug Administration also is working on guidelines to prevent Zika from contaminating blood supplies.

Health officials assume that Zika illness could surface in Stanislaus County in people returning from international travel.

The virus spread by mosquito bites may cause flulike illness with fever and body aches and conjunctivitis, or red eyes. The illness usually is mild and goes away within a week.

“It is rare for anyone to need to be hospitalized for it,” said Dr. John Walker, county public health officer. More severe illness is possible in people with chronic health conditions and a weakened immune system.

Stanislaus County public health has focused on travel advisories for local residents who are considering a trip to any region where Zika has spread. Posters in English and Spanish advise pregnant women to avoid travel to Mexico, Guatemala, Honduras, El Salvador and Panama, Caribbean islands and most countries in South America.

If a trip is absolutely necessary, pregnant women should consult with their medical provider. The precautions for travelers include aggressive use of insect repellant and wearing long sleeves and pants to minimize skin exposure.

The type of mosquitoes that carry Zika virus bite during the daytime hours, unlike mosquitoes that transmit West Nile virus in the Central Valley, which feed near dawn and dusk, Walker said.

Any pregnant woman who travels to those regions should visit her physician upon returning home, even if she’s not sick. A doctor’s appointment is essential if she has symptoms, because the CDC has testing guidelines for health providers.

Walker said his division and the medical community are working on preparations for potential cases. The Stanislaus Medical Society has forwarded information on CDC screening guidelines for Zika to member physicians. Doctors also were informed about Zika evaluation resources available from the California Medical Association.

According to the California Department of Public Health, no one has contracted Zika illness from mosquitoes or any other source in California. Nine travel-related cases have been reported in the state back to 2013, including three since Jan. 1. A Zika-infected person in Yolo County recently returned from travel outside the country and has recovered from symptoms.

The Zika virus is carried by yellow fever mosquitoes and another species, Asian tiger; neither are native to California. In the last five years, those mosquitoes have been detected in the state, from areas near the border with Mexico north to Madera and the Bay Area.

Unlike transmission of West Nile illness, which is spread by mosquitoes that bite infected birds and then people, Zika is transmitted after mosquitoes feed on people who have the virus in their blood, the CDPH says.

Walker said mosquito abatement districts in Stanislaus County are gearing up surveillance for the species capable of carrying Zika.

This story was originally published February 15, 2016 at 12:01 PM with the headline "Delta Blood Bank imposes donor restrictions to prevent Zika virus contamination."