Combined oral and endoscopic mepacrine therapy in a case of persistent chronic symptomatic giardiasis

A meta-analysis of the efficacy of albendazole compared with tinidazole as treatments for Giardia infections in children

Metronidazole is frequently used against Giardia infection; however, it has been associated with significant failure rates in clearing parasites from the gut; additionally, as it should be taken for 5 to 10 days, it is associated with poor compliance, probably due to side effects. Other drugs, including tinidazole (TNZ) and albendazole (ABZ) have been included in the antigiardial armamentarium. Our aim was to assess the efficacy of ABZ compared with TNZ in Giardia infections in children. A systematic review and a meta-analysis were carried out. PubMed, Medline, EMBASE, CENTRAL, and LILACS were searched electronically until February 2015. Also relevant journals and references of studies included therein were hand-searched for randomised controlled trials (RCTs). The meta-analysis was limited to RCTs evaluating the use of ABZ compared with TNZ in children with Giardia infection. The assessed outcome was parasitological efficacy. Prediction intervals (PI) were computed to better express uncertainties in the effect estimates. Five RCTs including 403 children were included. Overall, TNZ significantly outperformed ABZ without differences between subgroups defined by ABZ dosages [relative risk, (RR) 1.61 (95% CI): (1.40-1.85); P<0.0001]. The 95% prediction interval range is 1.28-2.02. There was no significant heterogeneity (I(2)=0%; Q-test of heterogeneity P=0.4507. The number-needed-to-treat, the average number of patients who need to be treated with TNZ to gain one additional good outcome as compared with ABZ was 4, 95% CI: 3-5. Our results show that TNZ outperforms ABZ in the treatment of Giardia infections in children from developing countries.

Management of chronic Giardia infection

Advances in our understanding of chronic giardiasis (CG) may improve our care of patients in this stage of the disease. This review proposes a new concept of CG and highlights the recent advances in our understanding and management of this condition. According to this review, management requires, initially, an accurate diagnosis, which may exclude several conditions that can mimic CG. Optimal treatment requires a tailored approach which includes the recognition of the known modifiable causes of this health condition, assessment of symptoms and potential complications, their treatment utilizing, if necessary, a multidisciplinary team, and an ongoing monitoring for the effect of therapy - weighing the efficacy of individual drugs - all of these together may lead to a successful treatment of CG.

Quinacrine-resistant Giardia duodenalis

Quinacrine resistance has been induced in 3 Giardia duodenalis laboratory stocks and 4 lines resistant to other drugs. The quinacrine-resistant lines were maintained in normally lethal levels of 5 microM quinacrine and some lines are viable in 20 microM levels of the drug. Fluorescence studies indicated that quinacrine was taken up by sensitive cells but was actively excluded from resistant trophozoites. The nuclei were not a site of drug accumulation and no specific fluorescence in the trophozoite could be attributed to any structure. Blebs of concentrated drug appeared prior to disintegration of the membrane of drug-sensitive trophozoites exposed to drug overnight. Parasite lines already resistant to furazolidone adapted more readily to quinacrine exposure than drug-sensitive stocks. This multiple drug resistant phenotype was not as marked with metronidazole-resistant lines.