ULTRASONOGRAPHIC DETECTION OF LIVING ADULT WUCHERERIA-BANCROFTI USINGA 3.5-MHZ TRANSDUCER

Adult Wuchereria bancrofti can be readily detected by ultrasound in th e lymphatic vessels of the spermatic cord with a 7.5-MHz transducer, b ut most ultrasound machines in developing countries are equipped with 3.5-MHz transducers. To assess the potential for ultrasound as a tool for diagnosis and epidemiologic assessment in lymphatic filariasis, we compared the performance of 3.5-MHz and 7.5-MHz transducers in 61 men in Recife, Brazil. All men had three ultrasound examinations using a 3.5 MHz transducer and an examination with a 7.5-MHz probe. Using the 7.5-MHz transducer, adult W. bancrofti were detected in 41 men; 81 adu lt worm nests were detected. Sixty-four (79%) nests were detected with the 3.5-MHz probe, each on all three examinations. The 3.5-MHz probe correctly identified 35 (85.4%) of 41 men as infected; sensitivity inc reased with lymphatic vessel diameter. Ultrasonographic examination wi th a 3.5-MHz transducer is a sensitive method for detection of adult W . bancrofti in men and merits consideration as a tool for rapid epidem iologic assessment.