Doppler ultrasonography reveals adult-worm nests in the lymph vessels of children with brugian filariasis

Abstract

Although ultrasonography has allowed 'nests' of live adult worms and dilated lymphatics to be detected in the early stages of infection with Wuchereria bancrofti, previous attempts to locate such adult-worm nests in brugian filariasis have been unsuccessful. In this study, the successful location of live adult Brugia malayi parasites, in the lymphatics of the axilla, thigh, epitrochlear region and/or popliteal fossa of children aged 3-15 years, is described for the first time. The 'filarial dance sign' (FDS), which indicates the presence of live adult worms, was observed in six children with microfilaraemia and in eight children who, though amicrofilaraemic, either had experienced an episode of lymphoedema (one) or were only positive for antifilarial IgG4 antibodies (seven). In bancroftian infection, the adult-worm nests have mostly been seen in asymptomatic but microfilaraemic subjects. The suspected worm nests, 18 in the 14 children, were all confirmed using colour-power and pulse-wave Doppler examinations. The worm nests were distinctly smaller and the wriggling movements were less rapid and less conspicuous than those seen in bancroftian filariasis. The importance of these findings in the management and control of lymphatic filariasis is discussed.

Lymphatic filariasis in children: Clinical features, infection burdens and future prospects for elimination

“…In this population, it was found on screening that, while the prevalence of microfilaraemia by blood-smear examination was only 0·38%, the BR test was positive in 10·97%. Similar to what is seen by ICT card testing in bancroftian filariasis, the BR test thus identified nearly 27 times more 'infected' individuals in Brugia malayi infection than the conventional mf detection by blood smear examination (Shenoy et al 2007a(Shenoy et al , 2009). From the above group, 100 children were enrolled for the chemotherapy studies, out of which 77 tested positive for filaria-specific IgG4 antibody.…”

Lymphatic Filariasis: A Method to Identify Subclinical Lower Limb Change in PNG Adolescents

“…Infection often occurs in childhood but the obvious clinical effects of the disease such as filarial lymphedema or hydrocele may not occur until they reach adolescence [4]. Shenoy et al [5], [6] have shown covert abnormalities in the lymphatics with lymphoscintigraphy and worm nests by Doppler ultrasonography in B.malayi LF-infected adolescents as young as three years. Importantly, it has also been shown that these early lymphatic changes can be reversed by rug administration [7].…”

Clinical and Pathological Aspects of Filarial Lymphedema and Its Management

“…This has also been confirmed by prevalence studies on microfilaremia and filarial antigenemia in children [34,35]. Existence of live adult filarial worms has been shown on Doppler sonography and lymphatic dilatation by lymphoscintigraphy in children aged 3-15 yr [13,15]. This lymphatic pathology in infected children, since it is known to persist, might pave way for future development of disease manifestations.…”

“…Other common locations described in women and children are larger lymph vessels and lymph nodes draining to lower and upper limbs [11,12]. In brugian filariasis also adult worms were detected by Doppler sonography in the lymphatics of the inguinal and axillary regions in children [13]. The adult parasites live in these sites for 6-8 yr or more and are responsible for initiating the early pathology in LF.…”