As Massachusetts insect season goes from bad to worse, the risk of mosquito-borne illnesses is hitting a new high.

Health officials are urging residents to take precautions against diseases like West Nile virus and Eastern Equine Encephalitis, also known as Triple E.

Several towns in Plymouth and Worcester Counties began spraying for mosquitoes this week to decrease the threat.

“The spraying is one part of the solution, it is not the only solution,” Plymouth Commissioner of Health and Human Services Michelle Bratti told NBC10.

Anyone out at night is advised to use strong insect repellent, wear long sleeves and pants and drain standing water around their homes.

West Nile virus can cause flu-like symptoms, long-term complications, and in rare instances, death.

The Centers for Disease Control and Prevention have recorded 289 human cases of West Nile virus from 33 reporting states this year.

EEE has a higher fatality rate: around 30% of infected people, according to the CDC.