Tropical eosinophilia

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Tropical (pulmonary) eosinophilia, or TPE, is characterized by coughing, asthmatic attacks, and an enlarged spleen, and is caused by Wuchereria bancrofti , a filarial infection. It occurs most frequently in India and Southeast Asia. Tropical eosinophilia is considered a manifestation of a species of microfilaria. The filariasis is transmitted by a vector, specifically the bite of a Culex, Anopheles, or Aedes mosquito, and the microfilariae (larvae) take up residence in the lung tissue, hindering respiration and causing chest pain as the disease progresses. [1] This disease can be confused with tuberculosis, [2] asthma, or coughs related to roundworms. [3]


Tropical pulmonary eosinophilia is a rare, but well recognised, syndrome characterised by pulmonary interstitial infiltrates and marked peripheral eosinophilia. [4] This condition is more widely recognised and promptly diagnosed in filariasis-endemic regions, such as the Indian subcontinent, Africa, Asia and South America. In nonendemic countries, patients are commonly thought to have bronchial asthma. [5] [6] Chronic symptoms may delay the diagnosis by up to five years. [5] Early recognition and treatment with the antifilarial drug, diethylcarbamazine, is important, as delay before treatment may lead to progressive interstitial fibrosis and irreversible impairment. [7]

The condition of marked eosinophilia with pulmonary involvement was first termed tropical pulmonary eosinophilia in 1950. [8] The syndrome is caused by a distinct hypersensitive immunological reaction to microfilariae of W. bancrofti and Brugia malayi . [7] [9] However, only a small percentage (< 0.5%) [10] of the 130 million people globally who are infected with filariasis apparently develop this reaction. The clearance of rapidly opsonised microfilariae from the bloodstream results in a hypersensitive immunological process and abnormal recruitment of eosinophils, as reflected by extremely high IgE levels of over 1000 kU/L. [7] [11] The typical patient is a young adult man from the Indian subcontinent. [9]


A persistent or recurrent cough that gets aggravated at night, weakness, weight loss and a low fever raises the possible diagnosis of this disease. Some children with this disease may also have enlarged lymph nodes in the neck and elsewhere. Others may cough up a little blood and may also have a wheeze. [2]


The diagnostic criteria for tropical pulmonary eosinophilia [11] include:

High antifilarial IgG titers to microfilariae often result in cross reactivity with other nonfilarial helminth antigens, [12] [13] such as strongyloides and schistosoma antigens, as demonstrated in reported cases. It is important to exclude other parasitic infections before tropical pulmonary eosinophilia is diagnosed, by serological tests, examination of stool specimens in a laboratory experienced in parasitic infections, or a trial of anthelmintic medication. Other parasitic infections, such as the zoonotic filariae, dirofilariasis, ascariasis, strongyloides, visceral larva migrans and hookworm disease, may also be confused with tropical pulmonary eosinophilia because of overlapping clinical features, serological profile and response to diethylcarbamazine. [7] [11] [13] [14] Radiological findings are nonspecific, with normal appearance on chest X-ray in up to 20% of patients. [9] Lung biopsy is not part of the routine diagnostic workup of tropical pulmonary eosinophilia. [4]


The dramatic response to a commonly used drug for filaria (diethylcarbamazine) almost confirms the diagnosis. No universal treatment guidelines have been established for tropical pulmonary eosinophilia. [5] The antifilarial diethylcarbamazine (6 mg/kg/day in three divided doses [4] for 21 days [10] remains the main therapeutic agent, and is generally well tolerated. Reported side effects include headache, fever, pruritus and gastrointestinal upset. [15] The eosinophil count often falls dramatically within 7–10 days of starting treatment. [4] [7]

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<i>Loa loa</i> filariasis

Loa loa filariasis is a skin and eye disease caused by the nematode worm Loa loa. Humans contract this disease through the bite of a deer fly or mango fly, the vectors for Loa loa. The adult Loa loa filarial worm migrates throughout the subcutaneous tissues of humans, occasionally crossing into subconjunctival tissues of the eye where it can be easily observed. Loa loa does not normally affect one's vision but can be painful when moving about the eyeball or across the bridge of the nose. The disease can cause red itchy swellings below the skin called "Calabar swellings". The disease is treated with the drug diethylcarbamazine (DEC), and when appropriate, surgical methods may be employed to remove adult worms from the conjunctiva. Loiasis belongs to the so-called neglected diseases.

<i>Loa loa</i>

Loa loa is the filarial nematode (roundworm) species that causes Loa loa filariasis. Loa loa actually means "worm worm", but is commonly known as the "eye worm", as it localizes to the conjunctiva of the eye. Loa loa is commonly found in Africa. It mainly inhabits rain forests in West Africa and has native origins in Ethiopia. The disease caused by Loa loa is called loiasis and belongs to the so-called neglected diseases.


Diethylcarbamazine (DEC) is a medication used in the treatment of filariasis including lymphatic filariasis, tropical pulmonary eosinophilia, and loiasis. It may also be used for prevention of loiasis in those at high risk. While it has been used for onchocerciasis, ivermectin is preferred. It is taken by mouth.

Filariasis Parasitic disease caused by a family of nematode worms

Filariasis is a parasitic disease caused by an infection with roundworms of the Filarioidea type. These are spread by blood-feeding insects such as black flies and mosquitoes. They belong to the group of diseases called helminthiases.

<i>Wuchereria bancrofti</i>

Wuchereria bancrofti is a human parasitic worm (Filariworm) that is the major cause of lymphatic filariasis. It is one of the three parasitic worms, together with Brugia malayi and B. timori, that infect the lymphatic system to cause lymphatic filariasis. These filarial worms are spread by a variety of mosquito vector species. W. bancrofti is the most prevalent of the three and affects over 120 million people, primarily in Central Africa and the Nile delta, South and Central America, the tropical regions of Asia including southern China, and the Pacific islands. If left untreated, the infection can develop into a chronic disease called lymphatic filariasis. In rare conditions, it also causes tropical eosinophilia, an asthmatic disease. No vaccine is commercially available, but high rates of cure have been achieved with various antifilarial regimens and lymphatic filariasis is the target of the WHO Global Program to Eliminate Lymphatic Filariasis with the aim to eradicate the disease as a public-health problem by 2020.


Strongyloidiasis is a human parasitic disease caused by the nematode called Strongyloides stercoralis, or sometimes S. fülleborni which is a type of helminth. It belongs to a group of nematodes called roundworms. This intestinal worm can cause a number of symptoms in people, principally skin symptoms, abdominal pain, diarrhea and weight loss, among many other specific and vague symptoms in disseminated disease, and severe life-threatening conditions through hyperinfection. In some people, particularly those who require corticosteroids or other immunosuppressive medication, Strongyloides can cause a hyperinfection syndrome that can lead to death if untreated. The diagnosis is made by blood and stool tests. The medication ivermectin is widely used to treat strongyloidiasis.

<i>Brugia malayi</i>

Brugia malayi is a nematode (roundworm), one of the three causative agents of lymphatic filariasis in humans. Lymphatic filariasis, also known as elephantiasis, is a condition characterized by swelling of the lower limbs. The two other filarial causes of lymphatic filariasis are Wuchereria bancrofti and Brugia timori, which both differ from B. malayi morphologically, symptomatically, and in geographical extent.

<i>Dirofilaria immitis</i> Species of worm that causes parasitic disease in animals

Dirofilaria immitis, also known as heartworm or dog heartworm, is a parasitic roundworm that is a type of filarial worm, a small thread-like worm, that causes dirofilariasis. It is spread from host to host through the bites of mosquitoes. There are four genera of mosquitoes that transmit dirofilariasis, Aedes, Culex, Anopheles, and Mansonia. The definitive host is the dog, but it can also infect cats, wolves, coyotes, jackals, foxes, ferrets, red deers, pudús, bears, seals, sea lions and, under rare circumstances, humans.

Eosinophilic pneumonia is a disease in which an eosinophil, a type of white blood cell, accumulates in the lungs. These cells cause disruption of the normal air spaces (alveoli) where oxygen is extracted from the atmosphere. Several different kinds of eosinophilic pneumonia exist and can occur in any age group. The most common symptoms include cough, fever, difficulty breathing, and sweating at night. Eosinophilic pneumonia is diagnosed by a combination of characteristic symptoms, findings on a physical examination by a health provider, and the results of blood tests and X-rays. Prognosis is excellent once most eosinophilic pneumonia is recognized and treatment with corticosteroids is begun.

Löfflers syndrome

Löffler's syndrome is a disease in which eosinophils accumulate in the lung in response to a parasitic infection. The parasite can be Strongyloides stercoralis, Dirofilaria immitis or Ascaris which can enter the body through contact with the soil. The symptoms of Löffler's syndrome include those of a parasitic infection such as irritable bowel syndrome, abdominal pain and cramping, skin rashes and fatigue. Löffler's syndrome itself will cause difficulty breathing, coughing as well as a fever.

Acanthocheilonemiasis is a rare tropical infectious disease caused by a parasite known as Acanthocheilonema perstans. It can cause skin rashes, abdominal and chest pains, muscle and joint pains, neurological disorders and skin lumps. It is mainly found in Africa. The parasite is transmitted through the bite of small flies. Studies show that there are elevated levels of white blood cells.

Lymphatic filariasis

Lymphatic filariasis is a human disease caused by parasitic worms known as filarial worms. Most cases of the disease have no symptoms. Some people, however, develop a syndrome called elephantiasis, which is marked by severe swelling in the arms, legs, breasts, or genitals. The skin may become thicker as well, and the condition may become painful. The changes to the body have the potential to harm the person's social and economic situation.


Chyluria, also called chylous urine, is a medical condition involving the presence of chyle in the urine stream, which results in urine appearing milky white. The condition is usually classified as being either parasitic or non parasitic. It is a condition that is more prevalent among people of Africa and the Indian subcontinent.

<i>Mansonella perstans</i>

Mansonella perstans is a vector-borne human filarial nematode, transmitted by tiny blood-sucking flies called midges. Mansonella perstans is one of two filarial nematodes that causes serous cavity filariasis in humans. The other filarial nematode is Mansonella ozzardi. M. perstans is widespread in many parts of sub-Saharan Africa, parts of Central and South America, and the Caribbean.

Mansonelliasis is the condition of infection by the nematode Mansonella. The disease exists in Africa and tropical Americas, spread by biting midges or blackflies. It is usually asymptomatic.

Brugia timori is a human filarial parasitic nematode (roundworm) which causes the disease "Timor filariasis", or "Timorian filariasis". While this disease was first described in 1965, the identity of Brugia timori as the causative agent was not known until 1977. In that same year, Anopheles barbirostris was shown to be its primary vector. There is no known animal reservoir host.


The Filarioidea are a superfamily of highly specialised parasitic nematodes. Species within this superfamily are known as filarial worms or filariae. Infections with parasitic filarial worms cause disease conditions generically known as filariasis. Drugs against these worms are known as filaricides.

Mansonella streptocerca,, is the scientific name of a human parasitic roundworm causing the disease streptocerciasis. It is a common parasite in the skin of humans in the rain forests of Africa, where it is thought to be a parasite of chimpanzees, as well.


Brugia is a genus for a group of small roundworms. They are among roundworms that cause the parasitic disease filariasis. Specifically, of the three species known, Brugia malayi and Brugia timori cause lymphatic filariasis in humans; and Brugia pahangi and Brugia patei infect domestic cats, dogs and other animals. They are transmitted by the bite of mosquitos.

Lymphatic filariasis in India is the presence of the disease lymphatic filariasis in India and all the social response to it. In India 99% of infections come from a type of mosquito spreading a type of worm through a mosquito bite. The treatment plan provides 40 crore people in India with medication to eliminate the parasite. About 5 crore people in India were carrying the worm as of the early 2010s, which is 40% of all the cases in the world. With other countries around the world, India is participating in a global effort to eradicate lymphatic filariasis. If the worm is eliminated from India then the disease could be gone forever. In October 2019 the Union health minister Harsh Vardhan said that India's current plan is on schedule to eradicate filariasis by 2021.


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