NEW DELHI: Delhi reported its fifth monkeypox case with a 22-year-old African woman testing positive for the infection. The woman travelled to Nigeria a month ago and her reports came out positive on Friday night.
Meanwhile, group of global experts convened by WHO has agreed on new names for monkeypox virus variants, as part of ongoing efforts to align the names of the monkeypox disease, virus and variants—or clades—with current best practices. The experts agreed to name the clades using Roman numerals.
The monkeypox virus was named upon first discovery in 1958, before current best practices in naming diseases and viruses were adopted. Similarly for the name of the disease it causes. Major variants were identified by the geographic regions where they were known to circulate.
Current best practise is that newly-identified viruses, related disease, and virus variants should be given names with the aim to avoid causing offense to any cultural, social, national, regional, professional, or ethnic groups, and minimize any negative impact on trade, travel, tourism or animal welfare.
Disease: Assigning new names to existing diseases is the responsibility of WHO under the International Classification of Diseases and the WHO Family of International Health Related Classifications (WHO-FIC). WHO is holding an open consultation for a new disease name for monkeypox. Anyone wishing to propose new names can do so here (see ICD-11, Add proposals).
Virus: The naming of virus species is the responsibility of the International Committee on the Taxonomy of Viruses (ICTV), which has a process underway for the name of the monkeypox virus.
Variants/clades: The naming of variants for existing pathogens is normally the result of debate amongst scientists. In order to expedite agreement in the context of the current outbreak, WHO convened an ad hoc meeting on 8 August to enable virologists and public health experts to reach consensus on new terminology.
Experts in pox virology, evolutionary biology and representatives of research institutes from across the globe reviewed the phylogeny and nomenclature of known and new monkeypox virus variants or clades. They discussed the characteristics and evolution of monkeypox virus variants, their apparent phylogenetic and clinical differences, and potential consequences for public health and future virological and evolutionary research.
The group reached consensus on new nomenclature for the virus clades that is in line with best practices. They agreed on how the virus clades should be recorded and classified on genome sequence repository sites.
Consensus was reached to now refer to the former Congo Basin (Central African) clade as Clade one (I) and the former West African clade as Clade two (II). Additionally, it was agreed that the Clade II consists of two subclades.
The proper naming structure will be represented by a Roman numeral for the clade and a lower-case alphanumeric character for the subclades. Thus, the new naming convention comprises Clade I, Clade IIa and Clade IIb, with the latter referring primarily to the group of variants largely circulating in the 2022 global outbreak. The naming of lineages will be as proposed by scientists as the outbreak evolves. Experts will be reconvened as needed.
Monkeypox virus is an orthopoxvirus that causes a disease with symptoms similar, but less severe, to smallpox. While smallpox was eradicated in 1980, monkeypox continues to occur in countries of central and west Africa. Two distinct clade are identified: the west African clade and the Congo Basin clade, also known as the central African clade.
Monkeypox is a zoonosis: a disease that is transmitted from animals to humans. Cases are often found close to tropical rainforests where there are animals that carry the virus. Evidence of monkeypox virus infection has been found in animals including squirrels, Gambian poached rats, dormice, different species of monkeys and others.
Human-to-human transmission is limited, with the longest documented chain of transmission being 6 generations, meaning that the last person to be infected in this chain was 6 links away from the original sick person. It can be transmitted through contact with bodily fluids, lesions on the skin or on internal mucosal surfaces, such as in the mouth or throat, respiratory droplets and contaminated objects.
Detection of viral DNA by polymerase chain reaction (PCR) is the preferred laboratory test for monkeypox. The best diagnostic specimens are directly from the rash – skin, fluid or crusts, or biopsy where feasible. Antigen and antibody detection methods may not be useful as they do not distinguish between orthopoxviruses.