Indian Pediatrics Case Reports

: 2021  |  Volume : 1  |  Issue : 2  |  Page : 136-

The night wanderer: Microfilaria in peripheral blood smear

Vivek Sharma1, Rajiv Sharan1, Santosh Kumar2,  
1 Department of Pediatrics, Tata Motors Hospital, Jamshedpur, Jharkhand, India
2 Department of Pathology, Tata Motors Hospital, Jamshedpur, Jharkhand, India

Correspondence Address:
Dr. Vivek Sharma
Department of Pediatrics, Tata Motors Hospital, Jamshedpur - 831 004, Jharkhand

How to cite this article:
Sharma V, Sharan R, Kumar S. The night wanderer: Microfilaria in peripheral blood smear.Indian Pediatr Case Rep 2021;1:136-136

How to cite this URL:
Sharma V, Sharan R, Kumar S. The night wanderer: Microfilaria in peripheral blood smear. Indian Pediatr Case Rep [serial online] 2021 [cited 2021 Sep 21 ];1:136-136
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Full Text

Lymphatic filariasis (LF) is caused by Wuchereria bancrofti (90%), Brugia malayi (<10%), and Brugia timori. Over 250 million children are exposed to LF worldwide. Common pediatric manifestations in endemic areas are asymptomatic infection or acute clinical manifestations by 11–15 years of age.[1]

A 13-year-old boy presented with painless swelling over the medial aspect of his left arm that was initially diagnosed as evolving cellulitis and treated with antibiotics. A possibility of LF was considered on finding high total leukocyte counts (10,480/mm3) with 25% eosinophilia. A provocative dose of diethyl carbamazine (DEC) was given, following which a nocturnal blood sample was collected and peripheral smears made. The diagnosis was clinched by identification of the W. bancrofti microfilaria (mf) based on the large size (>200 μm), presence of sheath, short head space, and anucleate tail [Figure 1] and web [video 1]. The child was treated with DEC (6 mg/kg/day).[2]{Figure 1}


Microfilariae usually circulate between 10 PM and 2 AM at night, coinciding with the usual feeding timing of mosquitos.[3] the prevalence rate of mf is 30% in children < 10 years and almost 69% in adolescents < 19 years. Two thin and two thick smears are made and stained with Giemsa or Hematoxylin. Species can be determined by the aforementioned morphological characteristics. An entire blood film should be scanned at ×10 before being reported as negative. Other diagnostic modalities include the detection of mf antigen by immune-diagnosis, Doppler sonography, lymphoscintigraphy, and histopathology.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

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There are no conflicts of interest.


1Mandal NN, Bal MS, Das MK, et al. Lymphatic filariasis in children: Age dependent prevalence in an area of India endemic for Wuchereria bancrofti infection. Trop Biomed 2010;27:41-6.
2Anitha K, Shenoy RK. Treatment of lymphatic filariasis: Current trends. Indian J Dermatol Venereol Leprol 2001;67:60-5.
3Aoki Y, Fujimaki Y, Tada I. Basic studies on filaria and filariasis. Trop Med Health 2011;39:51-5.