Evaluation of the efficacy of ribavirin therapy on survival of Crimean-Congo hemorrhagic fever patients: a case-control study.

The mortality rate resulting from Crimean-Congo hemorrhagic fever (CCHF) has been reported in different epidemics to range from 5% to more than 70%. While ribavirin has been recommended as the drug of choice in the treatment of CCHF, no consistent study has unequivocally demonstrated its effectiveness. Using the case-control method, we attempted to evaluate the efficacy of ribavirin in reducing mortality among CCHF cases admitted to Boo-Ali Educational Hospital in Zahedan, Iran, during the years 2000 to 2006. Sixteen deaths among CCHF cases were compared with 47 cases of survival. All patients had a definitive diagnosis based on the results of IgG and IgM capture ELISA tests recorded in their files. Ribavirin therapy for patients who survived had begun on average approximately 24 h earlier than the initiation of ribavirin therapy in the cases of death (P=0.033), and about 2 days earlier in non-bleeding survivors than in bleeding survivors (P=0.013). Based on the results of a multivariable analysis, the most important variables found to enhance survival were the time interval between the disease onset and ribavirin prescription (P=0.004), the time interval between bleeding onset and ribavirin prescription (P=0.037), and the time interval between disease onset and bleeding onset (P=0.014). Based on our findings, ribavirin appears to exert a marked effect on disease outcome, especially when it is prescribed within the first 4 days of the disease.