Mosquito-borne Diseases


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)

Arbovirus Total
Dengue 53*
Chikungunya 4
Zika 13

Hawaii 10 year summary of confirmed cases

Arbovirus 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015
Dengue 4 8 14 6 6 12** 7 10 14 209*
Chikungunya N/R N/R N/R N/R N/R N/R N/R N/R 22 6
Zika N/R N/R N/R N/R N/R N/R N/R N/R N/R 4

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 Branch808-586-4586

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
Oahu: 808-586-4708
Maui: 808-873-3560
Kauai: 808-241-3306

Additional Resources