Zika Mosquitoes

Aedes aegypti mosquitoes are the main species that carry the Zika virus.

(The Associated Press)

The summer Olympics are just around the corner in Brazil and here in the United States mosquito season is in full swing.

So is the Zika virus.

By last Wednesday, more than 1,600 people were infected in the United States, including 15 in Oregon, according to the federal Centers for Disease Control and Prevention.

All of those cases were linked to a trip abroad, with travelers becoming infected during their trip or coming home and sexually transmitting the virus to a partner.

But late last week, the virus popped up in the United States directly for the first time: In Miami, 14 people were infected by Monday.

The virus is carried by two types of mosquitoes: Aedes aegypti and Aedes albopictus. They exist in Brazil and other parts of South America and in areas of the United States, including California, Florida and Hawaii.

Oregon has largely been spared. Aedes aegypti has never been found in the state, and only once - in 2001 in Multnomah County - has Aedes albopictus turned up, according to Emilio DeBess, Oregon's state public health veterinarian.

"Since then we haven't seen any," DeBess said.

He doubts Oregon would ever see Aedes aegypti, which prefer tropical climates, but warm weather could draw Aedes albopictus from California.

Health officials in Jackson and Klamath counties have set out traps for the mosquitoes, DeBess said. So have officials in Multnomah County, where Aedes albopictus turned up that one season.

Unlike most mosquitoes, those that carry Zika are most likely to bite during the day.

Symptoms of infection include fever, rash and red eye, though four in five people never develop symptoms. But the virus can cause microcephaly, a serious brain defect in children. Infected in the womb, they can be born with a head that's smaller than average. In severe cases, the children end up with serious developmental defects.

As of late July, the CDC said more than 430 pregnant women in the United States had been infected with the virus. That includes one woman in Oregon. DeBess declined to name the county where she lives on the advice of public health lawyers.

In Brazil, about 5,000 children have been born with microcephaly, sparking concern leading up to the Olympics.

The CDC recommends that women who are pregnant or planning to conceive should stay away from Zika-affected areas, if possible. Men and women who have been to a high-risk area should delay pregnancy. If their partner travels to an area of risk, the couple should practice safe sex.

To avoid getting infected by a mosquito, the CDC recommends that travelers:

Use an insect repellent registered with the Environmental Protection Agency that contains one of the following ingredients: DEET, Picaridin, KBR 3023, Bayrepel, icaridin, oil of lemon eucalyptus, para-menthane-diol or IR3535.

Wear long-sleeved shirts and long pants.

Get rid of standing water, which attracts mosquitoes.

Stay in places with air conditioning or that use window and door screens.

Sleep under a mosquito bed net if they can't protect themselves from mosquitoes inside.

Get rid of standing water where mosquitoes lay their eggs.

Protection is key.

This is a disease that you can protect yourself against," DeBess said. "If you're in Oregon the likelihood of finding these two types of mosquitoes is very low, but we do recommend protection because there is also West Nile out there that we need to be concerned about."

-- Lynne Terry