Lymphatic filariasis is a tropical infectious disease due to infestation of the human lymphatic system with parasitic worms. Men are a particular risk group, especially for chronic lymphatic filariasis, which is associated with severe swelling in the genital area.
What is lymphatic filariasis?
Lymphatic filariasis is a disease of the lymphatic system that occurs in the tropics and is due to infection with certain worms (called filariae) of the nematode family, which are transmitted by mosquitoes. Lymphatic filariasis manifests itself after an incubation period of one month to several years by acute inflammation of the lymph nodes and vessels, fever attacks, asthmatic complaints and allergic cough (acute phase). In the advanced stage of the disease, lymphatic filariasis can lead to permanent damage to the lymphatic vessels, as a result of which the lymphatic fluid can no longer drain away and lymphatic varices (dilations of the lymph nodes and vessels) form. Immigration of lymphatic fluid into adjacent structures results in the development of lymphedema, which can take on extreme manifestations in the limbs, genitalia, and chest, leading to elephantiasis, a characteristic of chronic lymphatic filariasis.
Causes
Lymphatic filariasis is due to infection with filamentous worms (filariae) of the nematode (threadworm) family. The main causative agents of lymphatic filariasis are Wuchereria bancrofti (Africa, Southeast Asia, Central and South America, Pacific), Brugia malayi (Southeast Asia), and Brugia timori (Indonesia). The pathogens of lymphatic filariasis are transmitted by mosquitoes, so-called Anopheles, which have previously contracted worm larvae (microfilariae) from an infected human. These mature in the organism of the mosquito into larvae capable of infection. When a human is bitten by an infected mosquito, the microfilariae settle via the bloodstream in the lymphatic system, where they mature into sexually active filariae, give rise to further larvae, and cause the inflammatory reactions characteristic of the acute stage of lymphatic filariasis. Approximately three to eight months after infection, the microfilariae first infiltrate the blood system of the person infected with lymphatic filariasis.
Symptoms, complaints, and signs
Lymphatic filariasis can be manifested by a wide variety of symptoms. The first signs of illness often do not appear for months or years. At the earliest, fever episodes and swollen lymph nodes appear three months after infection. Due to the obstruction of the lymphatic channels, inflammation of the lymph vessels and nodes can occur repeatedly. If not treated, permanent damage to the lymphatic system may remain. Prior to this, lymphedema typically develops, causing swelling of the chest, genitals and limbs. The area around the infection hurts and causes an uncomfortable feeling of pressure when touched. In extreme cases, lympathic filariasis can cause respiratory problems, resulting in an asthma attack. This is accompanied by general signs of illness such as fatigue and exhaustion. Those affected feel physically and mentally exhausted and are usually no longer able to perform daily tasks. Externally, the disease of the lymphatic system can be recognized by the visible swellings and the sickly appearance of the affected person. The physician may detect elevated blood levels of eosinophilic granulocytes, which clearly indicate filariasis. If prompt treatment is given, the symptoms usually subside quickly. However, as a result of the weakening of the immune system, secondary fungal or bacterial infections may occur that require independent therapy.
Diagnosis and course
Because lymphatic filariasis is a tropical infectious disease, stays abroad in the areas at risk provide an initial clue with regard to diagnosis. In addition, lymphatic filariasis is diagnosed on the basis of the characteristic symptoms. In the course of a blood analysis, an increased concentration of eosinophilic white blood cells in the serum (eosinophilia) as well as antibodies specific for filariae can be detected. In the later course (chronic filariasis), microfilariae can be detected in the serum.Since the pathogens infiltrate the blood mainly at night, the blood sample should be taken at this time. If diagnosed early and therapy is started in time, the infectious disease has a good prognosis. If left untreated, lymphatic filariasis leads to severe courses and very pronounced swellings (elephantiasis), which can be a considerable psychological burden for those affected.
Complications
In this disease, affected individuals suffer primarily from a very high fever. It further also comes to a strong exhaustion and likewise to a tiredness of the patient. The resilience is also significantly reduced, so that it may possibly come to various restrictions in the everyday life of the affected person. Furthermore, inflammation of the lymph nodes occurs, which can lead to pain. In severe cases, the affected person suffers an asthma attack and generally has breathing difficulties. Severe breathing difficulties can also lead to a loss of consciousness, during which the affected person can also suffer a fall and injure themselves. Furthermore, swelling also occurs. It is not uncommon for patients to also suffer from psychological distress or depression. The patient’s quality of life is considerably reduced and limited by this disease. The treatment of this disease is usually carried out with the help of medication. No particular complications occur. However, some of the drugs may cause side effects, possibly headaches or fever. As a rule, the course of the disease is positive during the treatment. However, the immune system must recover after treatment, so the affected person is more susceptible to other diseases or infections.
When should you go to the doctor?
As soon as the typical signs of lympathic filariasis are noticed, a visit to the doctor’s office is advised. If the symptoms do not resolve on their own after a few days or even become more severe, a physician must also be informed. The affected person is best to speak immediately with the family doctor, who can clarify or exclude filariasis. Subsequently, the appropriate treatment can be initiated and thus further complications or late effects can be averted. If the symptoms occur a few months after a trip to one of the risk areas, a visit to the doctor is recommended. A mosquito bite on vacation should be clarified by a doctor immediately after returning to the home country. Attention must also be paid to any warning signs after contact with a possibly infected person. Lymphatic filariasis is treated by a general practitioner or internist. In severe cases, a lymphologist or infectious disease specialist clinic must be consulted. Children must be presented to a pediatrician immediately if they show signs of lympathic filariasis.
Treatment and therapy
Therapeutic measures are aimed primarily at killing the pathogens with the help of anthelmintics (vermifuge drugs). These drugs contain specific toxins that negatively affect the metabolism of the pathogens. Good results have been achieved in this regard with diethylcarbamazine, with the drug being administered over several days depending on the body weight of the affected person (e.g. 50 mg on day 1,3 x 50 mg on day 2, 3 x 100 mg on day 3 and 3 x 2 mg/kg body weight from day 4 to 21 of treatment). However, diethylcarbamazine may cause side effects in the form of headache and fever. In addition, ivermectin (avermectin) is used for the treatment of microfilariae and albendazole (anthelmintic) is used against adult (adult) pathogens. Under certain circumstances, microfilariae are present in the lymphatic structures that have already encapsulated themselves and accordingly do not respond to therapy. In these cases, treatment of lymphatic filariasis must be repeated. Since the immune system is severely weakened in lymphatic filariasis, secondary infections (fungi, bacteria) may be present in some cases and should be treated accordingly. Lymphatic drainage is helpful against lymphatic congestion. In cases of severe lymphedema (elephantiasis), surgical measures may be indicated for lymphatic filariasis to relieve lymphatic congestion.
Outlook and prognosis
The tropical disease has a favorable prognosis once medical treatment is sought. The administration of medications usually results in rapid relief of the existing symptoms.After a few weeks, the affected person can be discharged from treatment as cured. Without seeking medical care, there is often a deterioration in overall health. Delays in the healing process are to be expected and respiratory problems occur. These can trigger anxiety or an acute and therefore life-threatening situation. Therefore, for a favorable prognosis, consultation with a physician should occur at the first signs and physical changes. With a stable immune system, the pathogens can usually be fought quickly. The prescribed medication supports the body’s own defense system in the healing process and helps to remove the dead pathogens from the organism as quickly as possible. In addition, lymphatic drainage helps to combat lymphatic congestion. With these treatment measures, the affected person is in a good position and has a good chance of a speedy recovery. If complications arise, surgical measures must be initiated. Surgery is associated with risks and can trigger complications. If the operation proceeds without any problems, the patient is then treated with medication. Supportive optimal nutrition should take place for a good prognosis.
Prevention
Because no vaccine is available against lymphatic filariasis to date, preventive measures are limited to exposure prophylaxis. This consists of wearing long clothing , the use of mosquito nets , which may be impregnated with insect repellents, and the use of so-called reppelents (mosquito-repellent gels, sprays, lotions, creams) that protect against mosquito bites and thus lymphatic filariasis.
Aftercare
In this disease, high fever usually occurs in affected individuals. There is a permanent fatigue and exhaustion of the affected. The resilience is significantly reduced, so that there may be many restrictions in everyday life. The quality of life of sufferers is significantly impaired by the disease, so the help of friends and relatives is essential during this time. In severe cases, affected persons suffer from constant shortness of breath and asthma attacks, which is why they should refrain from physical exertion as far as possible. It is not uncommon for sufferers to suffer from severe depression and other mental illnesses, as sufferers can no longer actively participate in life. Support with the help of a psychologist can help to better accept the disease and make it easier to deal with it in the long term. In most cases, the treatment of the disease is carried out with the help of medications, which should be taken according to the prescribed dose. However, after the treatment, the immune system is weakened, so the sick people are more susceptible to infections, so it is recommended to avoid excessive actionism and gently resume everyday life.
This is what you can do yourself
Accompanying drug therapy, filariasis patients can take some measures themselves to support the healing process. Physical rest and bed rest are particularly important. Particularly in the first three to five days of the disease, the immune system should not be put under any further strain so that the worms can be flushed out as quickly as possible. A suitable diet additionally promotes recovery and also alleviates typical symptoms such as abdominal pain and nausea. The diet plan is best worked out with the help of a nutritionist. In the case of lymphatic congestion, weight should also be reduced. A healthy, low-salt diet combined with plenty of exercise (after the acute phase of the disease) and stress avoidance is recommended. If pain occurs, various remedies from natural medicine can be used in consultation with the doctor. Alternative preparations, for example belladonna, devil’s claw or arnica, may also help with headaches, fever and asthma attacks. Should major complications arise in the course of the disease, lymphatic filariasis must be taken to a doctor again. In the case of a severe course, it is essential to refrain from further self-help measures, insofar as the responsible physician does not suggest anything to the contrary.
