Characteristics of Helicase-primase Inhibitor Amenamevir-resistant Herpes Simplex Virus

Fatal HSV-2 primary infection most likely acquired by kidney transplantation: A case report

Herpes simplex virus 2 (HSV-2) rarely causes severe disease, even in solid organ transplant recipients. This paper describes a fatal case of HSV-2 infection, probably transmitted from a donor to a kidney transplant recipient. The donor was seropositive for HSV-2 but not for HSV-1, whereas the recipient was seronegative for both viruses before transplantation, suggesting that the graft was the source of infection. The recipient received valganciclovir prophylaxis due to cytomegalovirus seropositivity. Three months after transplantation, the recipient presented with rapidly disseminated cutaneous HSV-2 infection with meningoencephalitis. The HSV-2 strain was resistant to acyclovir, probably acquired under valganciclovir prophylaxis. Despite early initiation of acyclovir therapy, the patient died. This fatal case of HSV-2 infection, probably transmitted by the kidney graft with acyclovir-resistant HSV-2 from the onset, is uncommon.

40 Years after the Registration of Acyclovir: Do We Need New Anti-Herpetic Drugs?

Herpes simplex virus types 1 and 2 HSV1 and 2, namely varicella-zoster VZV and cytomegalovirus CMV, are among the most common pathogens worldwide. They remain in the host body for life. The course of infection with these viruses is often asymptomatic or mild and self-limiting, but in immunocompromised patients, such as solid organ or bone marrow transplant recipients, the course can be very severe or even life-threatening. Unfortunately, in the latter group, the highest percentage of infections with strains resistant to routinely used drugs is observed. On the other hand, frequent recurrences of genital herpes can be a problem even in people with normal immunity. Genital herpes also increases the risk of acquiring sexually transmitted diseases, including HIV infection and, if present in pregnant women, poses a risk to the fetus and newborn. Even more frequently than herpes simplex, congenital infections can be caused by cytomegalovirus. We present the most important anti-herpesviral agents, the mechanisms of resistance to these drugs, and the associated mutations in the viral genome. Special emphasis was placed on newly introduced drugs such as maribavir and brincidofovir. We also briefly discuss the most promising substances in preclinical testing as well as immunotherapy options and vaccines currently in use and under investigation.

High conservation of varicella-zoster virus helicase-primase complex, the target of the new antiviral drug amenamevir

Varicella-zoster virus (VZV) resistance to current antiviral drugs, that all target the viral DNA polymerase, represents a growing concern, notably among immunocompromised patients. Amenamevir, a novel antiviral that inhibits the VZV helicase-primase (HP) complex, is approved in Japan for the treatment of herpes zoster. In this study, we describe the low natural polymorphism of VZV HP complex (interstrain identity >99.7% both at nucleotide and amino acid levels) among 44 VZV clinical isolates. This work enabled to settle the maps of natural polymorphisms of VZV HP complex and to provide the genotypic tools for the monitoring of the emergence of VZV resistance to amenamevir in patients.