The Presence of Clade 9 Variant of Varicella Zoster Virus Found in India: ICMR-NIV

The Study Conducted by ICMR-NIV

The Indian Council of Medical Research-National Institute of Virology (ICMR-NIV) has for the first time found the presence of Clade 9 variant of varicella zoster virus (VZV) in India.

“The multi-country mpox (monkeypox) outbreak across the globe has led to the systematic surveillance of mpox cases in India. During the surveillance of mpox, we encountered cases of VZV in suspected mpox cases amongst children and adults,” said the new study published in the Annals of Medicine journal. This study focused on the genomic characterization of VZV in India.

Importance of the Study

• This is the first study reporting the circulation of VZV clade 9 in India.
• The variant is the most common strain in circulation in countries such as Germany, the UK, and the USA.
• Monkeypox disease symptoms are frequently mistaken for VZV, as their clinical presentations often closely resemble each other.
• Clinical differentiation between mpox and VZV is crucial for accurate diagnosis.
• No significant indications of heightened disease severity were found in patients infected with the VZV clade 9 strain.

Further Research and Findings

“Further studies warrant investigating the recombination patterns among wild-type and vaccinated populations to explore the evolution to help in disease monitoring and surveillance of VZV infections in India,” the study noted.

Study Methodology

• A total of 331 suspected cases were taken into consideration for the study.
• 22 cases were positive for monkeypox virus infection (15 from New Delhi and seven from Kerala).
• 17 were positive for Enteroviruses and one case was confirmed as Buffalopox virus.
• 28 cases were positive for VZV, with primary presentation of vesicular rashes all over the body.
• Other clinical manifestations included fever (82%), myalgia (46%), headache (36%), fatigue (29%), loss of appetite (14%), and lymphadenopathy (11%).