An Epidemiological Study of Outbreak Investigation of Chickenpox in Remote Hamlets of a Tribal State in India

Background: Chickenpox is a benign, self-limiting disease caused by the varicella-zoster virus (VZV) that is transmitted from person to person with direct contact or airborne spread, which usually lasts for five to seven days. There was a sudden increase in the number of cases of fever along with rashes at two sites in Jharkhand, India. We aimed to survey and establish the etiology and investigate the extent of the disease.

Methods: We defined the case of chickenpox as a person with acute onset of diffuse maculo-papulovesicular rash. From the clinically suspected cases, blood samples were collected and tested for anti-VZV immunoglobulin M and immunoglobulin G antibodies (depending on the clinical features) with an enzyme-linked immunosorbent assay (ELISA) kit (Novatec Immundiagnostica GmbH, Dietzenbach, Germany). A detailed history was collected from each case including the history of contacts and immunization status.

Results: The outbreak investigations were done at two villages of the two different blocks and one school in the Bharno block. According to the case definition, 16 persons were found affected by the varicella-zoster/chickenpox infection who belonged to five different households of Itkhori village in Chatra district. The age group varied from four to 45 years. The mean age was 20.28 years. Out of 16 cases, 10 (62.5%) cases complained of fever, rashes, and itching, two (12.5%) reported rashes and fever, and four (25%) complained of itching along with rashes. While at the Bharno block of Gumla district, out of 62 cases that fulfilled the case definition, 55 (88.7%) cases complained of fever, rashes, and itching, two (3.2%) reported itching and rashes, one (1.6%) reported vomiting along with fever and rashes, one (1.6%) complained about pain and rashes, one (1.6%) complained of cough with rashes, and four (25%) complained of itching along with rashes. There was neither any death nor any serious complication noted due to varicella.

Conclusion: Chickenpox is still widespread in Northern parts of India like Jharkhand. Most of the cases were self-limiting and recovered at the Itkhori block, while at the Bharno block, there were 20 active cases and the rest were either recovered or were still in the recovery phase.