Direct-acting antivirals and visceral leishmaniasis: a case report

BACKGROUND: Visceral leishmaniasis is a vector-borne parasitic disease caused by protozoa belonging to the genus Leishmania. The clinical presentation of visceral leishmaniasis strictly depends on the host immunocompetency, whereas depressive conditions of the immune system impair the capability to resolve the infection and allow reactivation from sites of latency of the parasite. CASE PRESENTATION: We describe a case of visceral leishmaniasis (VL) that occurred in a patient with chronic hepatitis C treated with direct-acting antiviral drugs (DAA). The hypothesized mechanism is the alteration of protective inflammation mechanisms secondary to DAA therapy. Downregulation of type II and III IFNs, their receptors, which accompany HCV clearance achieved during treatment with sofosbuvir and ribavirin might have a negative impact on a risk for reactivation of a previous Leishmania infection. We know indeed that IFN-γ is important to enhance killing mechanisms in macrophages, which are the primary target cells of Leishmania. CONCLUSION: Since VL is endemic in Sicily as well as in other countries of the Mediterranean basin, physicians should be aware of the possible unmasking of cryptic Leishmania infection by DAAs.