Some diseases are transmitted to humans by mosquitoes. These diseases often cycle back and forth from mosquito to human and back so that if an uninfected mosquito bites a human who is infected with one of these particular diseases, the mosquito can become infected themselves. After a certain period of time (e.g., a week), these mosquitoes become able to infect the next humans they bite. It is usually the female mosquitoes, rather than the males, that bite, so they can lay their eggs afterward.
Not all mosquitoes transmit diseases, and many diseases are only spread by certain mosquito species. For example, the mosquito-borne diseases dengue, chikungunya, and Zika are transmitted by the day-biting Aedes (Stegomyia) mosquitoes, which are found here in Hawaii. Specifically, Aedes albopictus may be found on all islands, while Aedes aegypti has only been found in some areas on the Big Island.
Mosquito-borne diseases may cause serious illness. You can protect yourself and your family by getting rid of mosquito breeding sites (i.e., areas with standing water) around your home and by taking steps to protect yourself from mosquito bites (like using mosquito repellent).
Other mosquito-borne diseases are not felt to be an immediate threat in Hawaii—e.g., because travelers are usually vaccinated (yellow fever) or disease spread requires a sick bird to travel all the way from the mainland (West Nile virus). Some mosquito-borne diseases (e.g., malaria or Japanese encephalitis virus) are not likely to ever be a threat because the mosquito species needed to spread the disease are not found in Hawaii. However, it is important for travelers to be aware of these serious diseases and where they occur in the world so they may protect themselves. (For health-related information for your travel destination, visit the Centers for Disease Control and Prevention’s (CDC) “Traveler’s Health” site.)
Case counts of mosquito-borne diseases of direct threat to Hawaii
Number of confirmed cases during 2016
As of January 3, 2017 (Case counts will be updated on the first working day of each month)
Hawaii 10 year summary of confirmed cases
These data are provisional and may be subject to change.
(Case counts for 2015 and 2016 are of Hawaii residents only.)
N/R = Not Reportable
*238 Hawaii resident dengue cases from 2015/2016 are attributable to an outbreak on the island of Hawaii
**5 dengue cases from 2011 are attributable to an outbreak on Oahu
For more information about specific diseases:
If you would like to report a possible case, contact:
Disease Investigation Branch: 808-586-4586
If you have questions or concerns about mosquitoes, contact Vector Control:
On the Big Island:
East Hawaii: 808-974-6001 or
West Hawaii: 808-322-4880
- Controlling Mosquito Breeding in Rainwater Catchment Systems and “Dry” Injection Wells
- Mosquito Bite Prevention for Travelers
- Bug Off! Using Mosquito Repellents
- Environmental Protection Agency (EPA) – Find the Insect Repellent that is Right for You
- Fight the Bite (Fact Sheet) (Flyer)
- Eliminate Breeding Sites
- Centers for Disease Control and Prevention (CDC) – Mosquito Control
- CDC – Division of Vector-Borne Diseases
- “Mosquito Bites Are Bad,” a fun and informative booklet developed by CDC for kids