Investigation of fatal chickenpox outbreak among adults in Northern Bangladesh, 2023

Although chickenpox is usually mild and self-limiting, severe complications and death may occur among adults. In April 2023, two adult deaths associated with clinically diagnosed chickenpox in a remote village of northern Bangladesh triggered notification of a suspected outbreak and prompted an investigation to describe its epidemiologic characteristics and contextual factors associated with severe adult cases.

A mixed-method outbreak investigation was conducted from April 15-19, 2023 in Thakurgaon district. Active case finding, household visits, line listing, and verbal autopsies were performed. Vesicular swabs were tested for varicella-zoster virus (VZV) by polymerase chain reaction (PCR). Environmental assessments and a focus group discussion explored contextual factors, community perceptions, and care-seeking behavior.

A total of 23 confirmed cases were identified, including seven laboratory-confirmed cases. The attack rate was 1.2% and the case fatality rate 8.7%. Adults over the age of 20 years comprised 52.2% of cases and males 60.9%. Both fatal cases were adult males with comorbidities, heavy smoking history, delayed care-seeking, pneumonia, and thrombocytopenia. All samples were PCR-positive for VZV. The epidemic curve suggested propagated transmission. Qualitative findings indicated reliance on traditional healers and delayed formal care.

Chickenpox can result in severe and fatal outcomes among adults in resource-limited settings. Early recognition and timely health care access are critical to reducing mortality.