- Thailand’s May-through-September rainy season is also the peak period for dengue fever
- The dengue virus can only be transmitted from mosquito-to-person; it is not transmitted person-to-person
- Infection symptoms include high fever, flu-like symptoms, and skin rashes
- You should see a doctor if you experience dengue symptoms
Thailand’s rainy season, running from May through September, is also the high risk period for dengue fever, a potentially serious condition most prevalent in tropical countries. Aedes aegypti mosquitoes carry the virus that causes dengue fever, and they infect 50 million people a year, including 500,000 serious cases requiring hospitalization. (source: WHO)
Transmission: Virus-carrying mosquitoes breed in clear water and are usually found in and around housing developments in urban areas. They are most active in the daytime. The virus can only be transmitted from mosquito to human; it is not passed from one person to another.
Symptoms: Once a person is bitten by a virus-carrying mosquito, symptoms only appear after an incubation period of three to 15 days (5 to 8 days in most cases). Dengue fever’s most common symptoms include:
- Sudden chills and pain around the eyes;
- High fever, up to 104° F / 40° C;
- Headaches, muscle pain and neck pain;
- Unexplained lethargy, loss of appetite;
- Nausea, vomiting and/or diarrhea;
- Skin rash that usual starts around the abdomen and upper torso.
The high fever and other symptoms usually persist for two to four days and are followed by a rapid drop in temperature and profuse sweating. Next, a temporary respite usually lasting about a day brings a feeling of well-being as body temperature returns to normal. That’s followed by a second round of fast-rising fever accompanied by a rash which spreads from the extremities until it covers the full body except the face. Some patients suffer swelling and redness on the palms and soles of their feet.
Treating dengue: There is no specific treatment for dengue fever, but it’s important to see your doctor if you develop dengue-like symptoms. In mild cases, doctors usually recommend patients drink plenty of fluids to prevent dehydration, take Tylenol or acetaminophen to relieve pain and reduce fever, and be sure to get plenty of rest.
More severe dengue cases require hospital admission. Patients usually undergo intravenous (IV) fluid and electrolyte replacement, blood pressure monitoring, and in some cases patients may require transfusions to replace lost blood.
Less than 1% of dengue cases are fatal. The acute phase of the illness marked by fever and muscle pain lasts about one to two weeks. Patients usually feel quite weak, and full recovery can take several weeks.
Prevention tips: Since the virus is transmitted mosquito-to-human, prevention entails both controlling and eradicating mosquitoes and taking action to protect oneself from being bitten.It’s important to empty standing water from places mosquitoes breed such as discarded old tires, trash cans and flower pots.
Wearing long pants and long-sleeve shirts helps guard against mosquito bites, and consider using a mosquito repellant containing DEET when visiting places where dengue is endemic. Avoid areas with standing water and stay indoors in the morning until two hours after sunrise and at sunset to further reduce your risk of being bitten. To learn more, log on to www.cdc.gov/dengue/
Dr. Asda Vibhagool, an Infectious Disease specialist Travel Medicine Center at Bumrungrad International Hospital, contributed to this article.