Do you experience joint pain after a mosquito bite? Beware of Chikungunya Fever.

Chikungunya fever is caused by the Chikungunya Virus and is a viral infectious disease primarily transmitted through the bites of Aedes mosquitoes. Clinical manifestations include fever, rash, and joint and muscle pain. Most patients improve within a week, but in 30% to 40% of cases, joint pain may persist for months or even years, posing a significant health risk.

I. How is Chikungunya Virus Transmitted?

Chikungunya virus is primarily transmitted through the bites of Aedes mosquitoes carrying the Chikungunya virus. In my country, the primary vectors are Aedes albopictus and Aedes aegypti.

After an Aedes mosquito bites a viremic human or animal, the virus replicates within the mosquito and then propagates in the salivary glands. It then spreads after an incubation period of 2 to 10 days. Rarely, transmission through blood transfusion or contact with infected blood, as well as mother-to-child transmission, can occur. However, the virus is not transmitted from person to person through casual contact or through coughing or sneezing.

II. What are the common symptoms of Chikungunya fever?

Most infected individuals develop symptoms 3–7 days (range 1–12 days) after being bitten by an infected mosquito. Symptoms commonly include sudden fever and joint pain. Joint pain primarily affects small joints such as the wrists and ankles, but can also affect larger joints such as the knees and shoulders. Severe joint pain can make movement difficult.

Other symptoms include headache, muscle pain, joint swelling, rash, nausea, and fatigue. Occasionally, complications of the eye, heart, and nervous system have been reported.

These symptoms are similar to those of other infections, such as dengue fever and Zika virus infection, and cases may be misdiagnosed. People at high risk for severe illness include newborns infected perinatally, those aged 65 and older, and those with underlying medical conditions such as hypertension, diabetes, or heart disease. Most patients improve within a week, but in some cases, joint pain may persist for months or even years.

III. How is Chikungunya treated?

Currently, there is no specific medication for Chikungunya. Supportive care is the primary approach.

Adequate rest, fluids, and over-the-counter pain relievers such as acetaminophen can alleviate some symptoms. Avoid taking aspirin or other nonsteroidal anti-inflammatory drugs (NSAIDs) (such as ibuprofen) until dengue fever has been ruled out to reduce the risk of bleeding.

IV. How is Chikungunya prevented?

The best way to prevent Chikungunya is to avoid mosquito bites. Specific measures include using mosquito repellent, wearing long-sleeved shirts and long pants, treating outer clothing with 0.5% permethrin, choosing a home with screened windows and doors, and using mosquito nets.

V. What precautions should travelers take?

Before departure, travelers should check health advisories and warnings for their destination country to identify areas experiencing outbreaks or experiencing a higher risk of Chikungunya infection. Some travelers, such as pregnant women, can use this information to determine whether to avoid travel to an area.

In areas currently free of outbreaks but with an increased risk of infection, those planning to stay longer or travel to areas experiencing outbreaks should consult a healthcare provider at a travel clinic or healthcare facility. When traveling, it is recommended to carry insect repellent containing active ingredients such as DEET, icaridin, oil of lemon eucalyptus, and para-menthane diol and use it according to the instructions.

Also, clothing and equipment treated with 0.5% permethrin (such as boots, socks, and tents) should be used, as well as mosquito nets, loose-fitting long-sleeved tops, and long pants. Whenever possible, choose accommodations with screened windows and doors.

Mosquito prevention should continue for two weeks after travel to ensure that travelers do not introduce pathogens such as chikungunya, dengue, and Zika virus into the country through undetected infection, which could lead to the spread of the disease.

After returning from travel, if you experience fever, headache, muscle and joint pain, or rash, please seek medical attention promptly and disclose the time and location of your travel so that you can receive prompt medical attention.

VI. How can individuals and families prevent and control mosquitoes?

01. Personal Protection

Residents should take personal protective measures near epidemic sites or in areas with high mosquito activity. Wear light-colored, long-sleeved clothing and pants when going out to minimize skin exposure. Use mosquito repellent, such as liquid or patches, as needed. Install screens on doors and windows indoors, and use mosquito nets at night.

02. Managing Indoor Water Stagnation

For hydroponic plants such as lucky bamboo, change the water completely every 3-5 days. Rinse the container walls and roots at the same time. Apply mosquito repellent or use physical barriers to prevent mosquitoes. Regularly check hidden areas such as water dispenser sinks and refrigerator trays to prevent water accumulation.

03. Managing Water Stagnation on Rooftops, Balconies, and in Front and Back of Houses

Rooftop ridges and gutters should be cleared regularly to prevent blockage and water accumulation. Weeds, flower pots, foam boxes, discarded bottles and cans, and other containers on balconies, rooftops, and courtyards should be promptly cleared. Unused containers should be stored upside down. Water storage containers, such as water tanks, should be covered, and discarded containers should be completely removed. Bamboo tubes and tree holes should be sealed or renovated, and fish should be raised in lotus ponds to prevent mosquitoes. Air conditioning condensate should be drained promptly. Discarded tires should be perforated or stored outdoors. Sewers should be sealed to prevent mosquitoes, and if possible, open drains should be converted to covered drains.

04. Indoor Mosquito Control

Qualified insecticide aerosols, mosquito coils, and incense coils can be used indoors to reduce mosquito bites.

When using smoke-generating mosquito repellent tablets or whole-house insecticide aerosols, doors and windows should be closed first. After application, leave the room and then open windows for thorough ventilation 30 minutes before reentering. If adult mosquitoes are found indoors, indoor mosquito control should be carried out promptly.

In addition, in areas with high mosquito populations, physical mosquito control tools such as electric mosquito swatters and mosquito lamps can be used in conjunction with other methods.

VII. What are common mosquito breeding grounds? How to clean them?

1. Homes and personal workplaces. Focus on aquatic plants, flower pots and trays, buckets, unused bottles and cans, water storage tanks, and courtyard drains. Primary measures include repotting and covering cans, switching from hydroponics to sandy soil cultivation, dredging drains, and applying mosquito larvae repellent.
2. Public areas such as residential communities, work units, and construction sites. Clean up indoor and outdoor breeding grounds, focusing on green belts, parking lots, temporary garbage or debris storage areas, underground garage water collection wells, drains, stairwells, building embankments and storm drains, and building depressions. Primary measures include cleaning unsanitary corners, repotting and filling with sand, and applying mosquito larvae repellent.
3. Public places and the surrounding environment. Focus on green belts, public parking lots, garbage and debris dumps, discarded tires, municipal pipe wells, water collection wells, drains, stairwells, building overhangs and storm drains, and building depressions. Primary measures include cleaning dead corners, emptying pots and cans, clearing and removing silt, landfilling with sand, and applying mosquito larvae killers.
4. Other mosquito breeding sites requiring special attention. Prioritize strengthening the cleanup of breeding sites in key locations, such as vacant homes, especially open-air old houses in urban villages, outdoor garbage and debris dumps, and dead corners in unused land, to reduce the risk of mosquito breeding.