ELephantiasis – disease of the tropics
Elephantiasis or lymphatic filariasis is a chronic disease of the tropics. Sometimes, it is called wuchereriasis. The condition occurs due to the infection of the lymphatic channels characterized by inflammation and obstruction of the lymphatic duct. The skin and subcutaneous tissues will become hypertrophic.
Elephantiasis is a rare disorder that cause by parasitic worms which are transmitted by mosquito. The lymphatic vessels will extremely inflame causing the affected area to enlarge. The most common affected sites are limbs or parts of the head and torso. Usual courses of disease are either acute disease, chronic or progressive.
Endemics area:
- South America
- Africa
- Asia
- tropics
- subtropics
Responsible organisms:
- Wuchereria bancrofti
- Brugia malayi
- Brugia timori
Pathophysiology:
The limbs or other affected parts will be enlarged as a result of obstruction of the lymph flow (and possibly the blood circulation as well). The lymphatic blockage can arise due to the recurrent attacks of a bacterial infection which causes inflammation of the lymphatic vessels (streptococcal lymphangitis). The lymphatic obstruction can progress, and when it is large enough, the back pressure in the lymphatic channels will lead to dilation of the superficial vessels. This will later cause a very severe swelling. Without proper treatment, the cycle will continue. The affected area will be extremely enlarged. The process will end up of gangrenous of that part of the body. It means that the surrounding tissue is dead due to obstructed blood supply.
There is a study done showing the likely cause of elephantiasis in Africa. There is a possibility of existence of small chemical particles in the red soil on which certain barefooted populations live. These particles will enter the skin through the feet then lodge in the lymphatic tissues and produce irritating effects. Streptococcal infection may occur on this traumatized tissue.
Clinical manifestation:
- Characterized by the gross enlargement of a limb or areas of the trunk or head – The severe swelling is caused by abnormal accumulation of watery fluid in the tissues (edema).
- The skin usually becomes thickened and pebbly appearance. In few parts, it may become ulcerated and darkened.
- Other possible features are fever, chills and a general feeling of ill health (malaise).
- This disease may also involve the male and female genital organs. In a male, it will result with enlarge scrotum with retracted penis. The skin will becomes thickened, non elastic, warm and tender. The spermatic cords also may be thickened as well.
- As for female, the vulva (external parts of the female genital organ) may also be affected by elephantiasis. The disease may manifest itself as a long, tumorous mass covered by thickened and ulcerated skin may develop between the thighs. The lymph nodes will later be enlarged.
Related disorder:
- Hereditary Lymph edema – a genetic disorder of the lymphatic system. Major symptoms may include swelling of the tissue under the skin resulting from obstruction, destruction or underdevelopment of lymph vessels and accumulation of excessive lymph fluid
- Secondary Lymph edema – a disorder of the lymphatic system resulting from infection. Symptoms may include sudden onset, chills, high fever and the presence of a red, hot, swollen leg. .
Investigations and diagnosis:
Diagnosis is made from the characteristic physical finding of lymphangitis or lymphatic obstruction plus underlying risk factor. In the absence of microfilaremia and lack of high technology method of investigation, it needs a high index of suspicion and patients should be diagnosed only by clinical grounds.
Eosinopholia can be found only during acute inflammation, otherwise full blood count is probably normal. Blood smear for investigation of microfilaria (larvae form of tissue filarial nematodes) is taken at midnight because microfilaria is nocturnal. In South Pacific, where the microfilaria is diurnal, the blood taking is done during daytime. In addition, the result may be negative at early of the disease progression, at first 2-3 years. For this purpose, Giemsa .staining is used. These larvae also can be identified in hydrocoele fluid or chylous urine.
Serology blood tests are useful, however it cannot distinguish between acute and past infection. The tests are:
- Bentonite flocculation
- Indirect haemagglutination
- ELISA
- Indirect fluorescent test
Rapid antigen test may be available with high specificity and sensitivity (90%). Sometimes, the adult worms can be found in lymph node biopsy for other causes (For diagnosis of elephantiasis, biopsy is not clinically indicated). Ultrasound of scrotal hydrocoele or lymphedematous breast may be helpful.
Treatment:
Chemotherapy is given to the patients mainly to attack the adult worms. Symptomatic treatment is given to repair the damage that has been caused by the body’s reaction to the presence of dead worms. Some effective drugs used in treating filariasis:
- Diethylcarbamazine (DEC, Heterazan, Banocide, and Notezine ) – An antihelmintic used primarily as the citrate in the treatment of elephantiasis (particularly infestations with Wuchereria bancrofti or Loa loa).
- Ivermectin (Mectizan) – This drug is a broad spectrum antiparasitic. It is active against microfilaria (not the adult form).
- Mebendazole – This is a broad-spectrum antihelmintic and effective against many diseases.
- Levamisole
- Suramin (Antrypol )
- Metrifonate (Trichlorphon)
- Antibacterial agents – This drug is used to reduce the growth or reproduction of bacteria. It will be given if there any evidence of secondary bacterial infection.
Lymphatic system failure will expose the affected part to microbial infections. Proper antiseptically hygienic care will minimized the risk. Surgery can be performed aiming to remove or bypass damaged lymphatic regions. Fulguration and plastic surgery will be helpful. Elastic stockings (or bandage) also will provide some benefit.
Prevention and disease control:
1) Pesticides control (e.g.: with insecticides, insect repellent) may help. Mosquito is a vector that transmits this parasite.
2) Annual doses of effective drugs (antiparasitic and antihilmentic) are an effective method of community bases treatment.
3) WHO strategy method is a mass treatment (e.g.: single annual dose of diethylcarbamazepine and albendazole) for high risk community.
4) A simple prevention as wearing slippers/shoes when walking may offer benefit to some extent.
Reference:
- Griffith’s 5-Minute Clinical Consult. Mark R.Dambro.2005
- http://elephantiasis.freeyellow.com/
- http://www.curehunter.com/public/keywordSummaryD004605-Elephantiasis–Filarial.do
- Stephen J. McPhee et al. Current Medical Diagnosis and Treatment 2009. Mc Graw Hill.
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Yes i think Elephantiasis is a rare disorder that cause by parasitic worms which are transmitted by mosquito.Good to read this post.
Elephantiasis or lymphatic filariasis is a chronic disease of the tropics. Sometimes, it is called wuchereriasis.