Alaskapox virus (AKPV) is a member of the Orthopoxvirus (OPXV) genus, which is within the Poxviridae family of double-stranded DNA viruses that infect a broad range of animal hosts from insects to vertebrates.AKPV was first identified from a shoulder lesion on a woman from Fairbanks, Alaska, USA in July 2015. The virus was initially called AK2015, then later named Alaskapox virus. Further cases in Fairbanks occurred in 2020 and 2021 to make up a total of four, which all presented with a small lesion on an extremity. All affected individuals completely recovered. Commonly reported symptoms of AKPV infection include fever, swollen lymph nodes (lymphadenopathy), muscle pain, and fatigue.
The four cases reported as of September 2021 were from people residing in low-density housing in forested areas. Evidence for human-to-human transmission has not been found. Animal-to-human transmission, potentially from small mammals, is suggested. AKPV was found to be carried by small animals, including voles, caught near the residences of individuals that had been infected. Human exposure is thought to have occurred through their pet cats or direct exposure outdoors. Physicians have recommended that people cover wounds with bandages since other poxviruses can spread by direct contact with skin lesions.
Poxviruses in the OPXV genus include variola virus, which causes smallpox in humans; vaccinia virus, which causes cowpox; and mpox.Vaccinia virus was used as a vaccine for smallpox in humans after it was discovered in the late eighteenth century by Dr. Edward Jenner that milkmaids exposed to cowpox seemed to be immune to smallpox. Smallpox vaccination is protective against other OPXV species. Smallpox is estimated to have killed 300-500 million people in the twentieth century and was eradicated by 1977. An increase in OPXV infections, noted around 2019, has been attributed to waning population immunity due to the discontinuation of routine smallpox vaccination after smallpox was eradicated.
The OPXV genus contains two distinct clades of viruses based on genomic sequence similarity, which correlates with historic geographic distribution in either the Old World or New World. The AKPV DNA sequence isolated in 2015 was analyzed on nine conserved genes and was sufficiently divergent from Old World and New World OPXV gene sequences to form a distinct clade. Most orthopoxviruses are thought to have originated from an ancestor or cowpox virus. Alaskapox virus is thought to have separated from its orthopoxvirus ancestor about 19,000 years ago.
