Ribavirin Therapy for Nipah Virus Infection

The January 2004 issue of the Journal of Virology contains a very interesting paper on protection of mice against lethal challenge with Nipah virus by vaccination and by passive transfer of antibody (2). However, in the Discussion the authors (referring to the Nipah virus epidemic which affected Malaysia in 1998) state that “ribavirin was tried on some patients but with no significant results.” This statement is misleading and not supported by the two references cited (1, 3). One of these references refers to a review article that I wrote in 2001; the only mention of Nipah virus in this paper is a speculative statement that ribavirin might prove of value in the treatment of Nipah virus infection, based solely on the known activity of this agent against other paramyxoviruses (3). The other paper cited (1) reported an open-label study of ribavirin in 140 patients with Nipah virus encephalitis, using as controls 54 similar patients who were managed before ribavirin became available or who refused treatment. Mortality in the ribavirin-treated limb was 32%, compared with 54% in the controls (P = 0.011). Duration of ventilation and total hospital stay were both significantly shorter in the ribavirin group (P = 0.0002 and <0.0001, respectively). There was a nonsignificant trend to a reduction in neurological deficits in survivors who received ribavirin (P = 0.17).

There is certainly a paucity of blinded, randomized, controlled trial data on the efficacy of ribavirin in this condition, but it is clearly quite incorrect, on the basis of the references cited, to say that ribavirin was ineffective, and it would be a pity if potential researchers who read this article were deterred from studying the effects of ribavirin more thoroughly.