Marin health officials remind public of mosquito risks

Even as the coronavirus crisis continues to play out, health officials are urging Marin residents not to overlook another threat: mosquito-borne illnesses.

Mosquitoes are not known to transmit the coronavirus, but they are confirmed vectors of West Nile virus, Zika and other diseases, said Dr. Matt Willis, public health officer of Marin County.

“With all the attention to COVID-19, it’s easy to forget all the other things we have always worried about,” Willis said.

“We want to make sure that we are reducing the number of incidents of those things that we know how to prevent, especially if we are anticipating surges of COVID, so that we can continue to protect our resources,” he said. “And this is something that we can control.”

A month into spring, the Marin/Sonoma Mosquito and Vector Control District is already seeing an increase in mosquito populations and requests for service from the public, said spokeswoman Nizza Sequeira.

“With everyone spending more time at home now, it is extremely important for them to take this opportunity to check their yards for, and eliminate, stagnant water,” she said. Still water is a habitat for mosquitoes to lay eggs.

The West Nile virus is most commonly transmitted to humans by mosquitoes, according to the Centers for Disease Control and Prevention. There are no medications to treat or prevent the infection, and most people who contract the disease will have no symptoms.

Of those infected with the West Nile virus, only 20% will develop a fever. Fewer than 1% will experience a serious neurological illness that can be fatal. People with diabetes or hypertension, or who are 50 years or older, are at greater risk of serious complications, according to public health officials.

The vector control district is continuing its routine surveillance of mosquitoes and dead birds during the coronavirus pandemic. There have been no documented cases of West Nile virus in Marin or Sonoma counties so far this year, Sequeira said.

“The virus is endemic to both counties, and in previous years it has been detected as early as May,” Sequiera said. “However, more recently initial detection has occurred during the summer and early fall. This could be due to warm temperatures accelerating both the mosquito life cycle and the amplification of the virus.”

Mosquitoes infected with West Nile virus were last detected in 2018, Sequeira said.

Leave a Comment

Your email address will not be published. Required fields are marked *