Most patients affected by Bancroftian filariasis (BF) are asymptomatic, with the development of features correlating with the number of adult worms residing in the body [1]. Clinical manifestations occur in one-third of cases.

The course of the disease is broadly divided into 3 phases: an asymptomatic stage of microfilaremia, an acute stage characterized by acute adenolymphangitis (ADL) and a chronic phase of irreversible lymphedema; the latter may be superimposed by recurrent episodes of ADL.

Acute adenolymphangitis is seen due to an immune-mediated reaction to the dying adult nematodes, with patients presenting with bouts of sudden onset of fever and painful lymphadenopathy [2]. The most common sites encompass the inguinal lymph nodes and the lower limbs. It may involve the genitalia in males [3]. In general, the inflammation subsides in 4-7 days. Recurrences occur commonly, being directly correlated with the severity of lymphedema [4]. The breakdown of skin barriers may lead to secondary bacterial infections in the skin covering the inflamed lymph nodes [5].

Other acute manifestations include self-limited episodes of pyrexia, termed filarial fever. Tropical pulmonary eosinophilia (TPE) may be present in a few individuals. Characterized by nocturnal wheezing and a dry cough, TPE is thought to be a hyperimmune reaction to the microfilariae trapped inside the lungs [6].

The primary chronic manifestation of BF is lymphedema, which refers to a localized limb swelling arising due to chronic inflammation of the lymphatic vessels. It is characterized by pitting/non-pitting edema with the overlying skin hyperpigmented and hyperkeratotic. Severe lymphatic obstruction is referred to as elephantiasis.

Some individuals may also develop proteinuria, hematuria or polyarthritis, presumably resulting from immune complex depositions [7].

• Laboratory Technician

  Slides were examined independently by bright field microscopy (magnification x100), by two experienced laboratory technicians. [journals.plos.org]

• Noncompliance

  Objective: The aim was to assess the coverage, compliance, factors-related to noncompliance to MDA. [tropicalparasitology.org]

• Large Joint Involvement

  All had large joint involvement, the commonest joint affected being the knee joint. Involvement was monoarticular in 10 and binarticular in 9. Joint pain was present in 18 and effusion in 12. Five patients had recurrent episodes. [link.springer.com]

• Swelling of Hand

  Fever and swelling of hands/body were reported as symptoms by 7.87% and 6.74%, respectively [Table 4]. [tropicalparasitology.org]

• Withdrawn

  Blood should thus, ideally be withdrawn during this time interval. Notable exceptions include certain South Pacific variants that may be seen during the day. Generally, Wright’s or Giemsa stains are used. [symptoma.com]

• Incontinence

  Severe cases can lead to toxaemia, altered senses, and urinary incontinence. [mdpi.com]

• Urinary Incontinence

  Severe cases can lead to toxaemia, altered senses, and urinary incontinence. [mdpi.com]

• Excitement

  In an early laboratory experiment, this idea was put into practice with exciting results which suggested that the method could be used in still water breeding sites, as long as protection from wind was ensured, to prevent dispersal of the balls (Reiter [scielo.br]

  The entrance of warm blood into the mosquito may excite the young larvae, causing them pass down the proboscis into the human skin’ [ 7, 62, 63 ]. [mdpi.com]

• Frontal Headache

  Of those who received albendazole alone, one individual reported frontal headache, 2 dizziness, 1 adenitis and another 1 oedema of the right arm. [filariajournal.biomedcentral.com]

• Forgetful

  […] the drugs. [18] In their study from Purba Medinipur, West Bengal, India Chattopadhyay, et al. revealed "fear of side-effects" as the most common cause (41.5%) of noncompliance. [19] This high rate of noncompliance might be multifactorial, for example, forgetfulness [tropicalparasitology.org]

Diagnostic panel for Bancroftian filariasis comprises of blood smears for the detection of microfilariae and serologic tests.

The microscopic examination must be performed in all individuals suspected of having filariasis [8]. The nematodes tend to demonstrate nocturnal periodicity; microfilariae are maximally found in the blood between 10 pm and 2 am. Blood should thus, ideally be withdrawn during this time interval. Notable exceptions include certain South Pacific variants that may be seen during the day. Generally, Wright’s or Giemsa stains are used.

Serologic exams are done to identify either the circulating filarial antigens or the antifilarial antibodies. Antigen assays using immunochromatographic techniques qualitatively depict the presence of filarial adult worms. Antigen levels are known to be stable throughout the day and can hence, be performed at any time. Serologic tests may demonstrate elevated levels of immunoglobulins (Ig) G and IgE. Specific IgG4 antibodies are thought to be a marker of active filarial infection. However, these tests show cross-reactivity with other helminthic worms and may not be useful in differentiating the past from a current infection.

Ultrasonography and scintigraphy may be used to detect the presence of adult worms residing in the lymphatic vessels [9] [10]. Polymerase chain reaction (PCR) techniques are available to diagnose filarial infections.

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2. Partono F. The spectrum of disease in lymphatic filariasis. Ciba Found Symp. 1987;127:15–31.
3. Pani SP, Srividya A. Clinical manifestations of bancroftian filariasis with special reference to lymphoedema grading. Indian J Med Res. 1995;102:114–118.
4. Pani SP, Yuvaraj J, Vanamail P, Dhanda V, Michael E, Grenfell BT. Episodic adenolymphangitis and lymphoedema in patients with bancroftian filariasis. Trans R Soc Trop Med Hyg. 1995 Jan-Feb;89(1):72-4.
5. Dreyer G, Medeiros Z, Netto MJ, Leal NC, de Castro LG, Piessens WF. Acute attacks in the extremities of persons living in an area endemic for bancroftian filariasis: differentiation of two syndromes. Trans R Soc Trop Med Hyg. 1999;93:413–417.
6. Ong RK, Doyle RL. Tropical pulmonary eosinophilia. Chest. 1998;113:1673–1679.
7. Melrose WD. Lymphatic filariasis: new insights into an old disease. Int J Parasitol. 2002;32:947–960.
8. McCarthy J. Diagnosis of lymphatic filarial infection. In: Nutman TB. Lymphatic filariasis. London: Imperial College Press. 2000;p:27-141.
9. Amaral F, Dreyer G, Figueredo-Silva J. Live adult worms detected by ultrasonography in human bancroftian filariasis. Am J Trop Med Hyg 1994;50:735-757.
10. Anitha, K Shenoy RK. Treatment of lymphatic filariasis. Curr Trends Continuing Medical Education. 2001;67(2):60-65.