Monkeypox: strain A.2 found in 2 cases in India. All about the West African clade

In the latest update of Monkeypox virus cases in India, an analysis conducted by the Indian Council of Medical Research (ICMR) and the National Institute of Virology (NIV), it has been revealed that the first two cases of Monkeypox diagnosed in India, who were a duo who had returned from the United Arab Emirates – were infected with the A.2 virus strain.

The study’s findings were published in Research Square, a preprint server, and have not been peer-reviewed.

In particular, the A.2 strain is different from the strain at the origin of the worrying epidemic of Monkeypox cases in Europe.

Foreign returnees from the United Arab Emirates presented with fever, myalgia and vesicular lesions on the genital area with cervical lymphadenopathy. Oropharyngeal and nasopharyngeal swab, EDTA blood, serum, urine, lesion specimens from multiple sites were collected from both cases on the ninth day after illness onset.

Clinical specimens from both cases were tested with real-time PCR for the orthopoxvirus, monkeypox virus (MPXV).

“The whole genome sequences obtained from the skin lesions of cases 1 and 2 showed a similarity of 99.91 and 99.96% respectively with the West African clade MPXV_USA_2022_FL001. Phylogenetic analysis revealed that the two cases were infected with monkeypox virus strain A.2 which belongs to hMPXV-1A clade 3 (West African clade) lineage,” the ICMR study of NIV found.

“The West African clade is circulating in the current 2022 outbreaks in non-endemic countries. It is less severe than the Congolese lineage reported earlier,” Dr Yadav said.

Here’s everything you need to know about the A.2 strain of the Monkeypox virus

-The A.2 strain, which was detected in the United States last year, has not been linked to any major clusters. The current epidemic is caused by the B.1 strain of the monkeypox virus.

-West Africa and Central Africa (Congo Basin) are the two known clades of monkeypox virus, of which the Congo Basin strain causes more severe disease, 0-11 mortality % and increased transmissibility.

-The study revealed that both cases were infected with the A.2 strain of the monkeypox virus which belongs to the hMPXV-1A lineage of clade 3 (West African clade). Of the two known clades – West African and Central African – the West African clade is found to be less severe than the Central African lineage

_According to the study, people without a history of sexual contact can also contract the virus. In the first case, the person had a history of similar lesions among friends and contact with a suspected case of Monkeypox.

–Symptoms of patients infected with strain A.2

-The 35-year-old man had developed mild fever and myalgia on July 5. He developed multiple vesicular eruptions in the oral cavity and lips followed by a single lesion on the genital organ. He also had rashes on both hands.

-The 31-year-old man had developed dysuria and genital swelling on July 8. He traveled from Dubai to his hometown of Kerala on July 13. He checked himself into a local government hospital and suspected of being a case of monkeypox he was isolated in July. 16.

– The study indicated that the infection begins as a febrile illness with an average incubation of 5-13 days with lymphadenopathy, myalgia and headache, followed by deep umbilical vesicular or pustular eruptions.

-The rash mainly starts from the face (oral region), genital or perianal, then distributed centrifugally to other parts of the body and progresses over time to scab.

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