On Mosquitoes and Diseases

Published: August 21, 2015

Today, August 20 may seem like an ordinary day compared to the 21st, which was declared a special non-working holiday, the Ninoy Aquino Day. However, the 20th is not just another day. It is in fact, World Mosquito Day, in honor of Sir Ronald Ross, an Indian doctor who discovered in 1897 that Malaria is being transmitted by female mosquitoes. A separate observance for Malaria itself is being celebrated annually every 25th of April.

Our country has had its fair share of fatal cases involving malaria and the two other mosquito-borne diseases, dengue and chikungunya. Their symptoms are so similar that it would be hard to differentiate without laboratory testing. However, understanding them is important. After all, these three diseases are abundant in tropical countries such as ours.

Malaria is transmitted by infected mosquitoes, the Anopheles, through the bloodstream via a single-celled parasite called the plasmodium, which travels to the liver where it will mature and infect red blood cells. As these red blood cells get infected until they burst, more plasmodium will spread infecting more red blood cells. The infection spreads, leading to liver infection. However, symptoms may not appear until 8-25 days after the mosquito bite, but an enlarged spleen, that organ on the left side of your rib cage might give you an idea that you have been infected. The onset of high fever should prompt you to see medical attention immediately.

Dengue, on the other hand, has been ranked by the World Health Organization as the fastest spreading mosquito-borne viral disease in the world. It has been prevalent in the Philippines and other Asian countries for as long as I can remember, which was why the 15th of June was declared Dengue Day by the Association of South East Asian Nations on 2011. It still remains a public health threat which is why understanding it would help us save lives.

Dengue symptoms are visible from 3-14 days after the bite. The virus attacks white blood cells and other antibodies, which literally creates havoc on the immune system. The virus replicates until the cells die, which may result in low protein, low albumin, fluid in the lungs or in the stomach area, and eventually, death. Like malaria, the infected will suffer from high fever, but this time, with intense headache, and pain in the eyes. Excessive bleeding follows and in a severe case, bleeding in the nose and gums is reportedly common. Low platelet and white blood cell counts on laboratory tests may help identify if the victim has acquired the dengue virus.

Chikungunya, which is so similar to Dengue in symptoms and the fact it too, is transmitted by the same type of mosquito, the Aedes Aegypti, attacks the muscles, joints, skin and even the central nervous system. Although muscle and joint pains occur in both dengue and chikungunya, pains in the latter would be more intense and more pronounced.

While Dengue is most obvious with a low platelet count, bleeding and pain in the eyes, Chikungunya does not exhibit these symptoms. While fever occurs in all three, malaria is best known for chills/shivering then fever/sweating every 2 days. The best way to identify what has infected you would be laboratory tests as soon as unexplained fever occurs.

The public is more aware of the dangers of these diseases now then a decade ago, with health programs being launched in cities and municipalities targeting schools and residential areas where mosquitoes may thrive, and I applaud the local government officials who remain faithful in implementing these programs year after year. Hopefully, these programs would continue until we reach a dengue-free and malaria-free Philippines in the near future. Who knows? Perhaps by then, August 20 would be renamed World No More Mosquito Diseases Day.