The Application of Biomedical Engineering Techniques to the Diagnosis and Management of Tropical Diseases: A Review <s> Ultrasonography <s> Abstract Although the potent microfilaricidal activity of ivermectin is well established, its efficacy against adult Wuchereria bancrofti is unknown. We used longitudinal ultrasound examinations for periods of 3–9 months to assess directly the macrofilaricidal effect of a single 400 μg/kg dose of ivermectin in 15 men from Recife, Brazil who were infected with W. bancrofti . Before treatment, microfilarial densities ranged from 3 to 3098 microfilariae per mL of blood, and movements characteristic of the living adult worm (the ‘filaria dance sign’) were observed by ultrasound examination of the scrotal lymphatic vessels in all 15 men. Following treatment, microfilarial density was markedly reduced in all men, but the filaria dance sign remained unchanged in both location and pattern. Eight months after treatment, a dilated lymphatic vessel was surgically removed from one patient at the site of the filaria dance sign, and 3 intact adult worms were released. When given as a single 400 μg/kg dose, ivermectin had no observable effect on adult W. bancrofti . Therefore, prolonged suppression of microfilaraemia following treatment with ivermectin cannot be explained by a macrofilaricidal effect of the drug. Ultrasound is a valuable new tool for directly and rapidly assessing the macrofilaricidal efficacy of antifilarial drugs in lymphatic filariasis. <s> BIB001 </s> The Application of Biomedical Engineering Techniques to the Diagnosis and Management of Tropical Diseases: A Review <s> Ultrasonography <s> Summary ::: ::: ::: Detection of adult Wuchereria bancrofti by ultrasonography of the scrotal region in men is a suitable diagnostic tool for lymphatic filariasis, whereas there are only a few case reports of adult filariae observed by ultrasonography in women. We examined 35 microfilaraemic women ultrasonographically in sites of the body suspected as locations for worm nests. In 15 women the ‘filaria dance sign’ (FDS) was detected in various locations, some being novel, such as adult worms within lymphatic vessels between muscular fibres of the thighs. The surprisingly high number of worm nests detectable in microfilaraemic women recommends ultrasonography for diagnosis and treatment efficacy monitoring of female patients infected with W. bancrofti. <s> BIB002
Ultrasonography has been used to locate and study the movements of active adult filarial worms of Wuchereria bancrofti in the scrotal region in men as a diagnostic tool for lymphatic filariasis; while only a few cases of adult filariae are observed by ultrasonography in women. This movement of Wuchereria bancrofti is described as "filaria dance"; which is considered a sign of the presence of Wuchereria bancrofti worms BIB002 . Dreyer et al. BIB001 used longitudinal ultrasound examination to investigate the microfilaria dance sign in the scrotal lymphatic vessels. They found out that ultrasound is a beneficial tool to evaluate in a direct and fast way the usefulness of antifilarial drugs. In another study done by Mand et al. BIB002 , they used a portable ultrasound unit, a 7.5 MHz linear transducer and a 3.5 MHz curved array transducer to examine different positions in subjects' bodies; in order to locate worm nests. The findings showed that ultrasonography is suitable for diagnosis of Wuchereria bancrofti infection in female patients as well as males.