Systematic review of the effectiveness of selected drugs for preventive chemotherapy for Taenia solium taeniasis

Abstract

Background Preventive chemotherapy is a useful tool for the control of Taenia solium taeniasis and cysticercosis. The aim of this systematic review is to assess the scientific evidence concerning the effectiveness and safety of different drugs in preventive chemotherapy for T. solium taeniasis in endemic populations. Methods A systematic review was conducted of controlled and uncontrolled studies, assessing the efficacy and adverse effects (among other outcomes) of albendazole, niclosamide and/or praziquantel for preventive chemotherapy of T. solium taeniasis. A comprehensive search was conducted for published and unpublished studies. Two reviewers screened articles, completed the data extraction and assessment of risk of bias. A meta-analysis of cure rate and relative reduction in prevalence was performed. The protocol for this review was registered on the International prospective register of systematic reviews (PROSPERO), number CRD42018112533. Results We identified 3555 records, of which we included 20 primary studies reported across 33 articles. Meta-analyses of drug and dose showed that a single dose of praziquantel 10mg/kg, albendazole 400mg per day for three consecutive days, or niclosamide 2g, resulted in better cure rates for T. solium taeniasis (99.5%, 96.4% and 84.3%, respectively) than praziquantel 5mg/kg or single dose albendazole 400mg (89.0% and 52.0%, respectively). These findings

Impact of a 3-year mass drug administration pilot project for taeniasis control in Madagascar

“…The taenicide drug chosen was praziquantel [15,16], which is available in Madagascar as it is already used in other regions for control of schistosomiasis. Praziquantel was given as a single dose at 10 mg/kg, which is the WHO recommended dose for taeniasis [15] and is lower than the dose used for MDA for schistosomiasis (40 mg/kg).…”

“…This is much lower than the dose levels used for the treatment of cysticercosis when it is desired that the drug crosses the blood-brain barrier and affects the parasite (50mg/kg daily in three divided doses for 14-30 days, or 25mg/ kg given two-hourly in a single day scheme, or combined with albendazole at 50 mg/kg for 10 days) [15,29,30]. A recent review on drugs used for preventive chemotherapy for taeniasis [16], did not find evidence of severe side effects associated to the use of praziquantel at this dose. There has been a limited number of case reports of adverse events in neurocysticercosis patients, but it is unclear whether these reactions were coincidental occurrences.…”

The viewpoint by White and colleagues critiquing the evaluation of the safety and efficacy of mass chemotherapy for Taenia solium taeniasis is unsubstantiated

“…We note in the abstract, results and discussion that the results have a low certainty of evidence due to a high risk of bias in the included studies and heterogeneity in combined estimates. We also discuss the issues regarding the lack of sensitivity of microscopy and non-use of a species-specific diagnostic test (we present the different diagnostic methods used in S1 Table of the paper) [3]. We believe that we have presented a transparent and balanced account of the available evidence.…”

“…It was not possible to further stratify the results by the diagnostic test used due to the relatively small number of studies. However, more important than the diagnostic tests used is the fact that all studies had a high risk of bias due to issues such as lack of randomization, incomplete outcome data and lack of blinding of outcome assessors [3]; a fact also acknowledged in the abstract by the statement that the "findings have a low certainty of evidence." And this low certainty of evidence is independent of drug and dose used.…”

“…We excluded case reports from our systematic review because they have a very low level of evidence of effect, and chance cannot be ruled out [7,8]. Instead, 11 studies met the inclusion criteria and were included in the systematic review (Table 4 in [3]), with a combined participation of over 17,000 individuals. In addition, we conducted a supplementary search for studies reporting side-effects from treatment with any of the three drugs (results presented in S4 File) and the results are reported in the discussion [3].…”