During the rainy season, flooding often occurs in the streets and nooks and crannies around the house get waterlogged. Such standing water is closely associated in our minds with mosquitoes because we know that’s where they like to lay their eggs. Among the different species of mosquitos, Aedes, which especially favor such opportunities, are carriers of the very unpleasant disease of dengue fever.

What do we know about dengue fever?

Dengue Hemorrhagic Fever, as it is technically known, is a contagious disease caused by the dengue virus carried by female Aedes Aegypti mosquitos. The female aedes mosquito is active during the day and sucks human blood for food. When a mosquito bites the blood of a dengue virus carrier, the virus, which has an incubation period of 8-12 days, is embedded in the mosquito’s stomach wall and salivary glands. When a mosquito carrying the virus bites someone, that person will inevitably get dengue fever. Once the virus enters the human body, the incubation period averages 5-8 days (the shortest  period is 3 days and the longest 15 days), after which the patient begins to show symptoms.

There are four strains of dengue virus: DEN1, DEN2, DEN3 and DEN4. Outbreaks are caused by whichever of these four variants is circulating in the particular area. Once one is infected with any of them, the body is immune to all strains of dengue for 6-12 months. The body also maintains immunity against the infecting strain throughout life but infection by the other strains is still possible.

Dengue Fever Warning Signs

Dengue fever can affect people of all ages. However, it is more common among those of school age and early working age. Any of the following symptoms may indicate dengue fever:

·       Very high fever, even up to 40 degrees Celsius, for 2-7 days.

·       Loss of appetite, red face, headache.

·       Feeling pain in the body.

·       Nausea, vomiting and possible abdominal pain.

·       Some people may have red blood spots on their body. There may also be nose bleeding or scurvy and black stool.

Dengue Fever Symptoms

Dengue fever symptoms have 3 stages.

1.        High fever stage

·       High fever or fever over 40 degrees Celsius without going down for 2-7 days.

·       Loss of appetite.

·       Nausea, vomiting.

·       Headache.

·       Abdominal pain in the epigastric region.

·       Muscle pain and general body aches.

·       Red face, red body.

·       There may be a rash or bleeding spots on the skin.

·       60-90% of cases have abnormally enlarged liver and feel pain when it is pressed (occurs 3-4 days into the illness).

2.        Critical stage (shock and bleeding)

·       Fever abates (occurs in days 3-6 of the disease).

·       Symptoms deteriorate to a state of shock.

·       Feeling restless.

·       Rapid pulse.

·       Severe vomiting.

·       Stomachache.

·       Some patients may experience lethargy.

·       Less urine.

·       There may be bleeding in the stomach.

·       If there are no complications and treatment is in time, symptoms at this stage will persist for 1-2 days and then progress to stage 3.

3.        Recovery stage

·       General symptoms improve, no abdominal pain, no restlessness.

·       The pressure normalises.

·       Pulse normalises.

·       More urine.

·       Liver size decreases and returns to normal within 1-2 weeks.

·       Appetite returns and the patient is able to eat.

·       Often have red rashes on the legs, hands and feet.

·       Itchy hands and feet.

Diagnosis

Dengue fever symptoms are similar to influenza and other fever-related illnesses. In addition to observing the symptoms and taking the patient's history, the doctor will take blood and sputum samples and send them to a laboratory for the following tests:

1.        Complete blood count (CBC) check for abnormalities of all blood components, including red blood cells, white blood cells and platelets, and blood concentrations.

2.        Dengue Immunity Test (IgM), direct NSI Ag test, and PCR test for dengue virus. If the patient is found to have low platelets, low white blood cells, dark red blood cells, low blood pressure, and light, fast pulse, the patient may go into shock which requires immediate admission to intensive care.

Caring for dengue patients

·       Patients should drink plenty of water and ORS (Oral Rehydration Salts) or mineral salt water. Monitor the color of the urine to check if the body is sufficiently hydrated. If the color is light yellow, then the patient is drinking enough water. If it’s dark yellow or tea color, the body is still dehydrated.

·       Take paracetamol to reduce fever according to the dosage prescribed by the doctor. Taking too much can lead to hepatitis.

·       Do not give aspirin to patients as it may cause intestinal bleeding.

·       If patients vomit with blood, have black stools, vomit a lot, always feel they’re not drinking enough water, and/or have cold hands and feet, they should see a doctor immediately. These symptoms are warning signs of potential low blood pressure and possibly shock.

·       Caregivers can closely supervise patients and have meals with them. Dengue is not a contagious disease through contact or secretions.

·       If the patient has a fever and wants to take a shower, they can take a warm bath or wipe themselves with a warm water cloth. Using cold water may cause the patient to lose too much heat and develop chills.

Treatment

So far, there is no specific antiviral drug for dengue fever. Treatment comprises symptomatic care provided in a supportive manner which for maximum effectiveness must be coupled with accurate diagnosis. The doctor must understand the nature of the disease and keep a close watch on the patient, especially during the critical potentially life-threatening stage.

Dengue is preventable

·       Avoid mosquito bites by sleeping under a net or with the windows and doors completely closed, especially during the rainy season.

·       If sleeping in the open air or near an open window, wear fully covering clothes, including long sleeve shirt, long pants, and socks.

·       Use mosquito repellents such as mosquito killers and topical or spray types.

·       People who get dengue fever must be careful not to be bitten by mosquitoes within the first 5 days of the illness to prevent infecting others.

·       Eliminate breeding grounds for dengue-carrying mosquitoes:

o   Close water containers with a tight lid to prevent mosquitoes from laying eggs.

o   Change the water in small containers such as vases for flowers, rituals and decoration every day.

o   Turn water containers and basins upside down after use to prevent waterlogging.

o   If there is a pond that has plants, such as a lotus pond, fish such as guppies should be kept as they will eliminate the mosquito eggs and larvae.

o   Put sand in the saucers of pot plants as it will absorb excess water from watering. Pour out any excess water in the saucer every day.

o   Collect and destroy old bottles, jars, cans and tires that aren’t used anymore to prevent waterlogging.

o   Look for holes and wells around the house and get rid of them if you find any.

·       Patients aged 9-45 years with a history of dengue fever should consider vaccination to prevent being infected by other strains of the dengue virus.

Dengue fever breaks out in Thailand every year during the rainy season and there are large numbers of patients. If it isn’t accurately diagnosed early enough and appropriate treatment isn’t prescribed, infection with the virus can be life threatening. Of course, dengue fever is something no one wants to happen to themselves and their family. As ever, prevention is the best cure, so follow the above advice both in your home and your surrounding community. This will help prevent everyone from suffering sickness and worse.

Krungthai-AXA Life Insurance customers who have mild symptoms and want to check with a doctor can use the Krungthai-AXA Telehealth service on the Emma by AXA app. In case of high fever for several days, see a doctor at a hospital immediately. For more information, click https://www.krungthai-axa.co.th/th/health-services/telehealth.

References

·       Bangkok Hospital
https://bit.ly/3xhNvFD

·       Bumrungrad Hospital
https://www.bumrungrad.com/th/conditions/dengue-hemorrhagic-fever

·       Paolo Hospital
https://bit.ly/3tsZSNX

·       Faculty of Medicine, Siriraj Hospital
https://www.si.mahidol.ac.th/th/healthdetail.asp?aid=780

·       Siriraj Piyamaharajkarun Hospital
https://www.siphhospital.com/th/news/article/share/676/Dengue1