The National Institute of Virology (NIV) has detected the presence of the clade 9 variant of varicella-zoster virus (VZV), which causes chickenpox, for the first time in India. A clade is a distinct subspecies or group that derives from a common ancestor.
A scientist at NIV and an author of the study said Clade 9 is the predominant VZV strain in countries such as Germany, the UK and the US. However, this study marks the first documentation of VZV Clade 9 circulating in India.
The varicella-zoster virus can lead to chickenpox, primarily in children and adolescents, and in adults. It is one of nine known herpes viruses that infect humans.
In this recent study, scientists discovered that of 331 suspected VZV cases, 28 tested positive for VZV with a vesicular rash. Their analysis confirmed the presence of Clade 1, Clade 5, and significantly Clade 9 in India. Although Clade 1 and Clade 5 were previously identified in the country, this study marks the first identification of Clade 9 in India.
Health experts report that symptoms associated with Clade 9 chickenpox include rash, fever, loss of appetite, headache, fatigue, and a general feeling of illness. Chickenpox rash usually appears 2-3 weeks after exposure to the virus, which appears as a papule-like bump. As the rash develops, patients may experience additional symptoms, such as fever, headaches and body aches. This entire process unfolds within two weeks, and the patient remains infectious until a scab forms.