The Hawaii Department of Health has reported another travel-related case of dengue fever on the island of Maui, marking the second incident within a week following a similar case on Oahu. This recent occurrence adds to the growing concern about the potential spread of the mosquito-borne disease in the state.

According to the Hawaii Department of Health, these cases, along with several others throughout 2023, involve individuals who have recently traveled to regions outside the United States where dengue fever is prevalent. Dengue fever is a viral disease commonly found in tropical and subtropical areas, and its symptoms include sudden fever, severe headache, joint and eye pain, and rashes that typically resolve within one to two weeks. However, in rare cases, it can develop into dengue hemorrhagic fever, which can be fatal.

While dengue fever is not established or endemic in Hawaii, the state does harbor the species of mosquitoes capable of transmitting the disease. However, the recent cases have been limited to travelers returning from affected regions. The last locally acquired case of dengue fever in Hawaii was reported in 2016, resulting in a state of emergency declaration on the Big Island due to the outbreak. Within a span of four months, Hawaii witnessed its largest dengue fever outbreak in 70 years, with 250 confirmed cases, including both residents and visitors.

The absence of high numbers of Aedes aegypti mosquitoes, which are responsible for transmitting dengue fever, along with geographic and environmental factors, has prevented the establishment of dengue fever as an endemic disease in Hawaii. The state's remote location and the limited presence of dengue mosquitoes reduce the likelihood of widespread transmission. Hawaii's climate, characterized by seasonal variations in rainfall and temperature fluctuations, also plays a role in minimizing mosquito breeding and virus transmission.

Despite the current low risk of dengue fever becoming endemic in Hawaii, there are some factors that could increase the likelihood in the future. These include the accidental introduction of more Aedes aegypti or Aedes albopictus mosquitoes through cargo or human travel, changes in temperatures and rainfall patterns due to climate change, and the reintroduction of the virus by world travelers coming from dengue-prone regions.

Prevention remains the key to combat dengue fever. The development of a vaccine has been ongoing for a century, but challenges related to creating immunity against the different serotypes of the dengue virus have slowed progress. Currently, Dengvaxia is available for individuals who have previously had dengue fever or reside in specific areas with a high exposure to the virus. Another vaccine, Qdenga, is being designed for individuals who have not been previously infected. Furthermore, several other vaccines are being developed and show promise for the future.

While dengue fever is not endemic to Hawaii, it is crucial for residents and visitors to take precautions to avoid mosquito bites. This includes being cautious during peak mosquito activity times, using natural or chemical repellents, utilizing clothing with built-in mosquito repellent features, and staying away from shaded or freshwater areas where mosquitos may be present.

Outbreaks of dengue fever continue to occur in various parts of the world, including Central and South America, Asia, the Middle East, Africa, and the Caribbean. Countries such as Nicaragua, Belize, Honduras, and El Salvador have reported some of the highest rates of dengue cases.

The Hawaii Department of Health continues its efforts to minimize the risk of transmission and prevent outbreaks through mosquito surveillance, control measures, and public health interventions. By remaining proactive, the state aims to maintain Hawaii as a dengue-fever-free destination for residents and visitors alike.