Medical Journal of Dr. D.Y. Patil Vidyapeeth

: 2016  |  Volume : 9  |  Issue : 3  |  Page : 384--386

Filariasis: An unusual cause of effusion

HL Kishan Prasad 
 K S Hegde Medical Academy of Nitte University, Mangalore, Karnataka, India

Correspondence Address:
H L Kishan Prasad
Associate Professor of Pathology, K S Hegde Medical Academy of Nitte University, Mangalore - 575018, Karnataka

How to cite this article:
Kishan Prasad H L. Filariasis: An unusual cause of effusion.Med J DY Patil Univ 2016;9:384-386

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Kishan Prasad H L. Filariasis: An unusual cause of effusion. Med J DY Patil Univ [serial online] 2016 [cited 2023 Feb 5 ];9:384-386
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Filariasis is a tropical disease caused by various thread like parasites and their larvae affecting 170 million people in the tropical areas of Southeast Asia, South America, and Africa. WHO categorize filaria as "potentially eradicable" infectious disease. It is a major health problem in endemic areas, especially along sea coasts where lung manifestations are common. It is transmitted by the culex mosquito and caused by two species Wuchereria bancrofti and Brugia malayi, accounting for 90% and 10% of the cases, respectively. [1],[2]

Microfilaria (Mf) usually affects the lymphatic system but also the other organs, subcutaneous tissues, and serous cavities such as pleura and pericardium. These parasites have been isolated from many uncommon sites. Few case reports of filarial effusion have also been reported. These effusions tend to be chylous in nature due to leakage of chyle from the occluded thoracic duct. Non chylous effusions by Mf are rare. It is due to lymphangitis resulting from incomplete obstruction of lymphatics. Pericardial effusion is a rare manifestation of filariasis, and manifesting with recurrent effusion with cardiac tamponade has also been reported. The entry of Mf to the body cavities is still controversial. As in vector, Mf is capable of penetrating the tissues, move freely in and out of small, delicate vessels, lymphatic capillaries and tissues of the vertebrate host. Peripheral blood smear is negative for Mf in cases of secondary manifestations of filariasis. [1],[2],[3],[4],[5] Few case reports of effusion treated with diethylcarbamazine (DEC) has been reported and found it's not 100% effective in all cases as DEC does not act on Mf residing in lymphatics, and they migrates to pericardial space causing recurrent effusion. Such cases can be treated with a combination of ivermectin and albendazole. [6] It is, therefore, emphasized that a thorough examination of the effusion fluid for Mf is warranted in all patients with unexplained serous effusion. [1],[2],[3],[4],[5]

There are case reports of filariasis detected in association with malignancy. The Mf circulate in the vessels and lymphatic system, and any lesion causes vascular or lymphatic obstruction like tumors, they appear in the tissue fluid or shed off into the surface material. In malignancy, increased blood vasculature also causes the increased Mf at these sites. Many case reports of Mf found in effusion cytology, and aspirate smears are associated with tuberculosis, Non-Hodgkin lymphoma, malnutrition, and malignancies. Mf have been identified from aspirated material from a lymph node, breast lump, cutaneous swellings and also from bone marrow, bronchial aspirate, nipple discharge, ovarian cyst fluid, semen, and cervicovaginal smears. The finding of Mf in cytological smears was considered incidental, the association of Mf with debilitating condition suggests that it is an opportunistic infection. There are increasing reports of malignancy associated with filariasis. Hence, a careful search for malignant foci is warranted in all cases of filarial serous effusions. [3],[4],[5],[6]

Tropical pulmonary eosinophilia is another form of filariasis featured by pulmonary infiltrates on chest radiograph and peripheral eosinophilia. These are due to hypersensitivity response to the Mf of the lymphatic dwelling parasites. [2],[3]

In Indian scenario, tuberculosis or malignancy is the frequent cause of effusions. However, patients from endemic areas or with recurrent pleural effusions, filarial cause can also be considered. The presence of Mf in the body fluids and the successful response to treatment with DEC is the strong evidence of the Filarial etiology. In tropical countries, a careful search for Mf in centrifuged body fluid may be rewarding. [2],[3],[4]

The early detection of the disease thus enables productive, healthy life and rid from a lifetime of chronic disability. Conventional diagnostic methods include the demonstration of Mf in the blood smears or in the skin snips. Both of these procedures have high false-negative rates and may not be sensitive with atypical presentations like filarial effusions. [2],[3],[4],[5]

Filarial antigen detection in body fluids has immense value in immunoparasitology, and it can be used as a marker for the diagnosis of active infection. Purification and characterization of filarial antigen from body fluids is a prerequisite for identifying the antigens of immunodiagnostic importance. Several investigators have isolated filarial antigens from body fluids such as blood, urine, and hydrocele fluid to study the nature and properties of these antigens to use them as diagnostic reagents in the detection of bancroftian filariasis. There are considerable difficulties in obtaining required human parasite material due to lack of a suitable animal model. [1],[2]

To conclude, filariasis is endemic in many areas, and this will manifest with an atypical presentation like recurrent serous effusion or aspirate smears. A careful search for filariasis helps in early diagnosis and proper treatment.


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