Dengue fever derives from the dengue virus, which is carried by mosquitos. The virus is most commonly found in tropical climates, and has an increased risk during the rainy seasons. The symptoms of dengue fever range from mild to fatal if left untreated.
Causes of Dengue Fever
The dengue virus consists of 4 strains: DENV-1, DENV-2, DENV-3, and DENV-4. For all strains, the female mosquito is the leading carrier. As a mosquito bites a person who is already suffering from dengue fever, the virus gets stored in the stomach and saliva glands of the insect. After an incubation period of 12 days, anyone who is subsequently bitten by that same mosquito may contract the virus through the bite.
Dengue fever patients who have contracted one type of the dengue virus will become immune from this strain; however, should they come into contact with a different strain of dengue, then they will again suffer from the symptoms of dengue fever — which are often more extreme the second time around.
Every year there is a consistent spread of each strain of the dengue virus — as well as newer mutations and variations. As a result, the disease is very hard to eradicate, as people are unable to develop full immunity to the virus.
Risk Factors for Dengue Fever
Dengue fever can affect anyone; however, there is a higher risk of severe symptoms and complications for people in the following groups:
- Babies and older adults
- Pregnant women
- People with stomach ulcers
- Women on their period or those experiencing abnormal vaginal bleeding
- Those who suffer easily from hemolysis or any other issue related to abnormal hemoglobin
- People with congenital heart disease
- People who suffer from chronic diseases such as diabetes, high blood pressure, asthma, ischemic heart disease, kidney failure, or cirrhosis of the liver
- People who take corticosteroid or non-steroidal anti-inflammatory medications
Symptoms of Dengue Fever
Dengue fever symptoms include fever, headache, aching eye sockets, general aches and pains, joints or bones aches, and a rash resembling heat rash, with some cases experiencing bleeding such as nose bleeds or bleeding gums.
As for dengue hemorrhagic fever, symptoms include all the symptoms of dengue fever, but with specific additional symptoms including:
- A fever over 38 degrees Celsius for over 2-7 days
- Nausea, vomiting, and a loss of appetite
- Flush face, small red spots on the skin, or bleeding found in various areas such as nosebleeds, scurvy, and blood in urine or stools
- Severe stomach ache, which increases in pain if pressure is applied
- In certain severe cases where a patient has suffered from a fever for 2-7 days, they may also suffer from some blood circulation issues or go into shock, which is known as dengue shock syndrome. Symptoms include restlessness, cold toes or fingers, infrequent urination, decreased blood pressure, and an unmeasurable pulse.
With the exception of those who go into Dengue Shock Syndrome, after 2-7 days, fever should reduce, and blood circulation, blood pressure, and heart rate should stabilize. Within an additional 2 to 3 days, energy levels increase, stomach aches disappear, and appetite return. It is at this point that some develop a red heat rash like rash on the palms and soles of the feet; however, it should clear up within one week.
As dengue fever symptoms in its early stages are very similar to symptoms of other viral illnesses such as chikungunya virus and zika virus infection, in addition to observing the patient’s symptoms and reviewing their medical history, the doctor will carry out the following tests to accurately diagnose dengue fever:
- Complete Blood Count (CBC) to look for any anomalies in blood composition, including hemoglobin, leukocyte, platelets, and blood concentration
- Direct immunization of further dengue fever or NS1 Ag
Should a patient be found to have small spots of bleeding with a lowered platelet count, it is possible that they have contracted the dengue virus. However, if the platelet count is very low, in combination with lowered white blood cells, raised red blood cells, and a raised pulse, this is an indicator that they have already reached the Dengue Shock Syndrome phase and require immediate medical attention.
Treating Dengue Fever
There are currently no antiviral medications available for dengue fever and treatment is symptomatic. In mild cases, the fever can disappear within 2-7 days.
People suffering from dengue should drink plenty of water to replenish lost fluids. They should also bathe with warm water to reduce fever, eat easily digested foods, and take medications such as paracetamol to help reduce the fever. Patients should not take aspirin or any NSAID medications as these may increase the risk of bleeding.
Should a patient have a severe stomach ache with frequent vomiting, fast on-set of fever and and/or unusually cool body temperature, in addition to not having passed urine for more than 6 hours, it’s vital that they see a doctor immediately.
Preventing Dengue Fever
Dengue fever can be prevented in the following ways:
- Prevent mosquito bites by wearing clothes that fully covers exposed skin, and use insect repellants.
- Rid mosquitos of their breeding grounds near your home by covering any standing water to prevent mosquitos from laying eggs. Also, change the water in containers which cannot be covered, such as flower vases. Ensure the environment surrounding your home is clean and tidy, and there is not a single place which could become waterlogged, allowing for mosquitos to breed.
For anyone from age of 9-45 who has already experienced dengue fever, vaccinations against the other strains of dengue fever should be considered.