By Tedler D. Depaynos, MD
With the onset of the rainy season, the increased incidence of Dengue Fever is again very significant and some areas of our archipelago are even declared Epidemic Areas. A lawyer coffee mate described it as “Dengue Fever Time”. I am therefore constrained to once again write on this Infectious Disease and most of it I learned from Dra. Rhoda Orallo-Fajardo, an Infectious Disease specialist in one of our previous learning discussions.
Dengue Fever used to be spread by a daytime mosquito called Aedis Egypti that thrives on fresh water. With continuous rains their breeding places become abundant and this may explain their multiplication during rainy season. They were observed to bite mostly at 10 AM and 4 PM. At present, however, other types of mosquitoes that bite at night were also observed to spread the disease. Hence, Dengue Fever can now be spread day and night.
To help control Dengue, the mosquito breeding places where fresh water accumulates should be eradicated and this would only be effective if it is a community effort. Anti-mosquito sprays may also be done. At home flower pots, empty bottles and cans could be the breeding places.
A lady patient once claimed that while reviewing for their board exams, several of them got their Dengue from the mosquitoes in their classroom. Since then, they preferred to wear long sleeves and pants and even started to wear socks to avoid the mosquito bites. It was unfortunate that one of her classmates missed her exams because of complications.
The mosquito gets the virus by biting an infected individual. When it lays eggs or larvae, the mosquitoes produced would also carry the virus. Jokingly, they will not die because they are Dengue infected. The virus and the mosquitoes have a symbiotic relationship.
Dengue is made up of 4 strains so that even if you develop immunity from one Dengue attack, you could still be infected by the other strains. One could then have Dengue attacks 4 times in their life time. Dra. Fajardo could recall during our previous discussion that she had two cases or 2 patients who were infected with Dengue twice.
There are no reported cases yet that a pregnant mother at the first and second trimester could infect her fetus. It may be possible on the third trimester, but the mother develops anti bodies against the virus which is also transmitted to the fetus so that even if it would be infected, the antibodies will overcome the virus.
Dengue causes non-specific signs and symptoms and maybe similar to those caused by other viruses like fever, body malaise, joint pains and anorexia. However the fever in Dengue is usually high and joint pains are usually more severe. These may last for 3-5 days. When the high fever disappears, rashes appear. They may also be itchy but unlike in allergies they are not edematous. They may look like pinpoint pettechiae and flat and actually they are micro extravasations of blood.
Appearance of Chikungunya virus is suspected but I am not aware if it could already be confirmed in our locality by our local laboratories. Classically, it may have similar manifestations like Dengue but the rashes are mostly observed to appear together with the fever and the joint pains may last longer. Other viral diseases may also produce rashes but the fever may be milder and joint pains more tolerable.
Laboratory tests for Dengue are needed to confirm its presence. A simple Complete Blood Count (CBC) would suggest to us if the infection is bacterial or if it is viral. The Hemoglobin (Hb) in the CBC is a test for anemia but it may also tell us if the patient is dehydrated probably due to the continuous high fever and likewise the Platelets maybe seen normal or depressed. The Platelets are responsible for blood clotting mechanism and if it is severely depleted which may be caused by the Dengue Virus, the patient may bleed and may cause the Hb to decrease. Specific tests for early or late Dengue cases are also available.
There is no specific anti viral drugs yet given for the Dengue virus. In general, just like any viral infection, they are self-limiting. Patients are merely hydrated but monitored closely specially their Platelet count for possible complications. Patients with “warning signs” or with possible complications like “bleeding” are those that are advised confinement after a series of laboratory tests. Patients with no “warning signs” are treated as out-patients but still are advised follow-ups for possible sudden appearance of “warning signs”. These “warning signs” are defined by DOH and implemented by attending MDs.
Serious complications of Dengue are mainly due to bleeding caused by Platelet depletion. A patient could bleed anywhere like underneath the skin which may cause not only rashes but sometimes hematomas; in the intestinal walls manifesting bloody stools or melena; in the nasal cavity causing nose bleeding; in the lungs or even in the brain which may resemble a stroke. The virus may also cause extravasations of fluid from the blood vessels causing edema or even fluid in the lungs resulting in pleural effusion. It may directly affect also the heart muscles causing heart failure. Ultimate prevention or treatment may eventually be Platelet transfusions.
The serious complications we encountered several years ago were bleeding in the brain and bleeding in the lungs.
The origin of the word Dengue is unknown. **
