Chickenpox outbreak investigation - A Sabeen district, Sana’a city, Yemen, January -February 2019 (Preprint)

BACKGROUND Varicella zoster virus (VZV) causes chickenpox. Epidemiological profile of chickenpox varies considerably across countries, healthcare systems and immunization policies. In Yemen, chickenpox remains an important public health issue and outbreaks are not uncommon, since vaccination is not universal. On 23 February 2019, a medical doctor from AL kafji area of Assabain district notified to the Ministry of public Health& population Chickenpox infection among his family members and neighbors. OBJECTIVE To confirm the existence, describe epidemiological characteristics of the outbreak, and recommend prevention, and control measures. METHODS A door-to-door search was made for case finding and line listing with detailed epidemiological, clinical and vaccination history. Four blood samples were collected and sent for laboratory confirmation by ELISA. Data analyzed Epi info 7.2. RESULTS A total of 26 cases met the case definition. The outbreak started on 19 January 2019 at one house then transmitted to 2nd and 3rd neighbor houses. The Epi curve showed three peaks one for each house. The index case was male with 11 years old. The overall attack rate was 34% and the highest attack rate 56% was in the 3rd house. More than half 58% of cases were females and 46% was children in the age group 10-14 years. All cases suffered from rash with itching, 46% had vesicular lesion and 42% had lesions < 50. Eight percent of the cases had complications i.e. pneumonia. About 25% of samples was IgM positive. All cases were not vaccinated. CONCLUSIONS Chickenpox outbreak in AL kafji area of Assabain district was confirmed. Females were more affected than males. Introducing Chickenpox vaccine with the routine immunization, and increase the community awareness about mode of transmission and control measures for prevention are recommended.