Monkeypox in India: ICMR says A.2 strain of virus found in first two cases

The first two cases of monkeypox in India were infected with the virus strain A.2, which is different from the one causing the outbreak in Europe. This is revealed in an analysis by an institute of the Indian Council of Medical Research (ICMR).

The first two infected patients had returned from the UAE. The A.2 strain, which was detected in the US last year, has not been linked to major clusters.

The current outbreak is being driven by the B.1 strain of monkeypox virus, Dr Pragya Yadav, a senior scientist at the National Institute of Virology (NIV) and lead author of the study, said.

The findings of the study have been published in the Research Square, a pre-print server, and have not been peer reviewed. India has reported nine cases of monkeypox and one death so far.

The two cases of India

The foreign returnees from the United Arab Emirates presented with fever, myalgia, and vesicular lesions on the genital area with cervical lymphadenopathy.

The oropharyngeal and nasopharyngeal swab, EDTA blood, serum, urine, lesion samples from multiple sites were collected from both the cases on the ninth post onset day of illness.

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

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"The complete genome sequences obtained from skin lesions of cases 1 and 2 showed similarity of 99.91 and 99.96 per cent respectively with MPXV_USA_2022_FL001 West African clade. Phylogenetic analysis revealed that the two cases were infected with monkeypox virus strain A.2 which belong to hMPXV-1A lineage of clade 3 (West African clade)," the study by the NIV under the ICMR found.

The West African and Central African (Congo Basin) are the two known clades of the monkeypox virus, of which Congo basin strain causes more severe illness, 11 per cent mortality and increased transmissibility.

"The West African clade is found to be circulating in the current ongoing outbreaks of 2022 in non-endemic countries. It is which is less severe than Congo lineage reported earlier," Dr Yadav said.

Symptoms

The study said the infection starts with a febrile illness with average incubation of 5-13 days with lymphadenopathy, myalgia, and headache, followed by deep-seated umbilicated vesicular/pustular rashes.

The rash primarily starts from the face (oral), genital or perianal region and then distributed in centrifugal manner to other parts of the body and progresses over time to scab.

(With inputs from PTI)