Fascioliasis is a neglected zoonosis with major public health implications in humans. Although
triclabendazole (TCBZ) is the
drug of choice, there are records of TCBZ failure worldwide. TCBZ-resistant
fascioliasis is treated with alternative approved drugs including
nitazoxanide (
NTZ), with varying levels of efficacy. Data on
NTZ efficacy after TCBZ failure in Egypt is scarce. This study evaluated the efficacy of
NTZ in cases of TCBZ failure during an outbreak of
fascioliasis in Assiut governorate of Upper Egypt.
METHODOLOGY/PRINCIPAL FINDINGS: This prospective study included 67 patients from the outpatient clinic in Manfalout locality of Assiut governorate with clinical manifestations of acute
fascioliasis. These included high
eosinophilia (> 6% eosinophils in peripheral blood), positive anti-Fasciola
antibodies, and hepatic focal lesions (HFL) or
ascites on abdominal ultrasound or computed tomography. All patients initially received TCBZ at recommended doses. Patients were followed up after 1 month to assess response. According to the responses, patients were categorized as non-responders and responders. The non-responders received a trial of
NTZ and were re-assessed for response based on clinical manifestations, eosinophil count, and abdominal ultrasound. Patients not responding to
NTZ received additional doses of TCBZ. One month after initial TCBZ treatment, 37 patients responded well to TCBZ, while 30 patients failed to respond with persistence of
fever,
abdominal pain, high
eosinophilia, and HFL. Most non-responders were male (56.7%); females predominated among TCBZ responders (62.2%). The mean age of the non-responders was relatively lower, at 20.57 ± 14.47 years (p = 0.004). Following
NTZ therapy, HFL disappeared in 9/30 (30%) patients and eosinophil counts normalized in only 2 (6.7%) patients, indicating an overall efficacy of 36.6%. The remaining cases received additional doses of TCBZ with complete clinical, biochemical, and radiological resolution.
CONCLUSIONS/SIGNIFICANCE:
Nitazoxanide was partially effective in TCBZ failure in acute human
fascioliasis in Upper Egypt. Further studies with larger samples are highly encouraged and further research is urgently needed to find new therapeutic alternatives to TCBZ.