Lymphatic Filariasis

Definition: Lymphatic means relating to or secretion of the lymph. Filariasis is a parasitic disease caused by a filoriadea-type roundworm infection. Filariasis is a tropical disease caused by the presence of filarial worms, especially in lymph vessels, where elephantiasis may result from severe infection.

Lymphatic filariasis is a human disease caused by parasitic worms called filarial worms, also known as elephantiasis. Lymphatic filariasis is a neglected tropical condition caused by Wucheresia bancrofti, a mosquito-borne, thread-like, parasitic filarial worm infection. B.timori and Brugia Malayi. It is an ancient disease with important social and economic ramifications for individuals, families, and societies affected.

The worst effects of the chronic disease typically arise in adults, more frequently in men than in women and include, damage to the arms, legs, or genitals of the lymphatic system, resulting in extreme pain, widespread loss of productivity, and social isolation.

Epidemiology

• Over the past 20 years, a study has contributed to new treatment regimens, methods, and diagnostic techniques, which have significantly improved the outlook for managing lymphatic filariasis and led to the introduction of the Global Lymphatic Filariasis Elimination Program (2000). The key aim of the Global Programme for the Elimination of Lymphatic Filariasis (GPELF) is to disrupt the transmission of lymphatic filariasis through mass drug administration.
• Many species of mosquitoes in your key genera transmit lymphatic filariasis Anopheles culex, Aedes, and Monsonia- the distribution, performance varies considerably by vector species. The entomological aspects of the transmission of lymphatic filariasis are important to consider.
•  In India, lymphatic filariasis is a public health problem. Except for Jammu and Kashmir, Himachal Pradesh, Punjab, Haryana, and Delhi, the disease is endemic in India. Nagaland, Manipur, Tripura, Meghalaya, Sikkim, Arunachal Pradesh, Chandigarh, Rajasthan, Mizoram, Dadra, and Nagar Haveli. Surveys conducted over the past two decades, however, suggest that areas historically considered being free of filariasis show evidence of low levels of transmission. Highly infected areas are found in Uttar Pradesh, Bihar, Jharkhand, Andhra Pradesh, Orissa, Tamil Nadu, Kerala, and Gujarat.
• Epidemiological Determination: Infection with nematodes of the family Filariooidea causes lymphatic filariasis. 90% of infections are caused by Wucheresia bancrofti and much of the remainder by Brugia Malayi. The exclusive host of W.bancrofti infection in humans. Although some strains of Brugia Malayi, the life cycle of these animals usually remains epidemiologically different from that of humans. Malayi may also infect certain animal species.
•  Mosquitoes of the genus Culex Anopheles and Aedes are the primary vectors of W. bancrofti. Anopheles (in remote areas of Africa and Elsewhere) and Aedes (in the Pacific Islands).

Agents/Factor: There are eight species of filarial parasites that are specific to humans, They are Wucheresia bancrofti, Brugia Malayi, Brugia Timose.

 Host Factor: Man is a natural host.

(a) Age: All ages are vulnerable to infection; the infection rates rise with age up to 20-30 years.

(b) Gender: In most endemic areas, the MF rate is higher in men.

(c) Migration: Migration led to the extension of filariasis into non-endemic areas.

Environmental Factors: Climatic conditions, Drainage, and Town planning.

Incubation Period: Generally, 8 to 16 months.

Mode of Transmission

• Via mosquito bites, lymphatic filariasis is transmitted. People with microfilariae circulation are outwardly healthy, but mosquitoes spread the infection to others. The person with chronic filarial swelling suffers significantly from the disease, but the infection is no longer transmitted.
• In India, 99.4 percent of the cases are caused by the species-Wuchereria Bancroft, while 0.6 percent of the issue is caused by Brugia Malayi.
• Filarial worms in the vessels of the lymphatic system live in the adult stage. The lymphatic system is the lymph node and lymph vessel network that maintains the fluid balance between the tissues and the blood, which is a vital component of the immune defense system of the body.
• Filariasis is spread by the bite of mosquitoes infected with the vector. From the parasite, it is deposited near the site or puncture.
• It passes through or can penetrate the skin on its own through the punctured skin and eventually enter the lymphatic system.
• Transmission dynamics depend on the touch of the human mosquito (e.g. infective biting rate).

Symptoms of Lymphatic Filariasis

Lymphatic filariasis infection involves asymptomatic, acute, and chronic conditions.

1. Acute: Acute local inflammation episodes include: the skin, lymph nodes, and lymphatic vessels. The body’s immune response to the parasite triggers some of these episodes. However, most are the result of bacterial skin infection where, due to underlying lymphatic damage, normal defenses have been partially lost.

2. Early Symptoms: Red expanding target rash, feeling unwell or flu-like, headache, stiff neck, swollen lymph nodes, sound or light sensitivity.

 Laboratory Diagnosis

The standard method for diagnosing active infection is the identification of microfilariae in a blood smear by microscopic examination. 

Prevention and Control of Lymphatic Filariasis

Lymphedema can grow even after the adult worms die. To see lymphedema therapists for specialized treatment, you can ask your doctor for a referral. Preventing the worsening of lymphedema by following certain basic principles:

• Wash the swollen region carefully every day with soap and water.
• Elevate and exercise the swollen arm or leg to move the fluid and improve the lymph flow.
• Please clean any wounds. When required, use an antibacterial or antifungal cream.
• Prevention centers or mass care of anti-filariasis drugs to avoid mosquito larval ingestion, mosquito control action in public health, mosquito control action in public health, and individual action to prevent mosquito bites.
• Stay indoors during darkness, if possible, when mosquitoes are most aggressive in their quest for food.
• Wear long trousers and long-sleeved shirts while you are outside.
• Spray the exposed skin with repellent for insects.
• Controlling vectors.
• Destruction of vector breeding areas.
• When sleeping, using bed nets.
• Good hygiene with help reduces the spread of the parasites.
• Hand washes after handling infective pinworm larvae.
• Cleaning under your fingernails and not chewing your fingernails.
• Clothes, particularly underwear should be changed and washed daily to help prevent the spread of the disease.
• Treat each person infected in a household at the same time.

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