Lymphatic filariasis is an infection involving the lymphatic system that is triggered by one of the 3 species of roundworms. This infection is the usual cause of permanent disability globally. Among those who were infected, many individuals have been disfigured by the disease.
The infection is transmitted if an infected mosquito bites an individual and deposits larvae of the worm in the skin. The larvae travel to the lymphatic system where it matures. The adult worms might reach up to 1 ½ to 4 inches in length. The adults produce millions of immature larvae that circulate in the bloodstream and lymphatic system. The infection spreads if a mosquito bites an infected individual and bites another.
What are the symptoms?
Lymphatic filariasis have symptoms that are typically triggered by the adult worms. The microfilariae do not cause symptoms and steadily vanish from the bloodstream.
In the early phases of the infection, the symptoms manifest for 4-7 days such as swollen lymph nodes in the groin and armpits, fever, and pain in the groin and limbs. There is also buildup of pus in a leg and drain to the surface of the skin which results to a scar.
The bacterial infections of the skin and tissues beneath are likely since the worm makes the lymphatic system less capable to protect the body against infections. Oftentimes, once the symptoms resolve, they recur. It is more severe if an individual was exposed to the infection for the first time.
After several years of infection, the lymph vessels enlarge. Many individuals do not have any symptoms. In some, the swelling steadily becomes permanent. The legs are typically affected but the breasts, arms and genitals might be affected as well. The swelling develops due to the following:
- Adult worms thrive in the lymphatic system and diminish the flow of lymph fluid from the tissues, resulting to the back up of fluid in the lymph vessels.
- The worms trigger a reaction from the immune system that initiates inflammation and swelling.
The swelling can cause the skin to become spongy. If the skin is pressed on, it leaves an indentation that does not subside right away. The chronic swelling might make the skin hard and even thicken. Among men, the scrotum might also swell.
The ideal protection against lymphatic filariasis is to minimize the number of mosquito bites by observing the following:
- Applying insect repellants
- Use netting over beds at night time
- Wear long-sleeved shirts and long pants
- Wear clothing that has been saturated with the insecticide permethrin
In areas where lymphatic filariasis is prevalent, diethylcarbamazine or other medications are used to prevent infection. These drugs work by reducing the number of microfilariae in the blood of infected individuals, thus preventing the spread of the infection.