Director Medical Services (Health) Office of the DGMS (Army) USE OF IMMUNIZATION AS STRATEGY FOR OUTBREAK CONTROL OF VARICELLA ZOSTER IN AN INSTITUTIONAL SETTING Col VK Bhatti MD (Community Medicine), M Phil ( Clinical Epidemiology) & PGD Bioethics Director Medical Services (Health) Office of the DGMS (Army) Indian Army drbhatyy@Gmail.com

Aim of the Presentation Epidemiological investigation and control strategy undertaken in an Outbreak in health care providers, living in closed institutional setting

Background Information Outbreaks of Varicella common in Children Outbreak in health care providers living in closed institutional setting uncommon. Role of vaccination as post exposure prophylaxis for control of outbreak has not been studied extensively. There was an outbreak involving Nursing cadets in a tertiary care setting

Definition of Varicella Chickenpox (Varicella) is an acute infectious disease caused by exposure to Varicella-zoster virus (VZV) and is characterized by a maculo-papulo vesicular rash; fever and malaise

Material and Methods Health Intelligence Div alert Identification of the Index case. List of contacts drawn Screening of contacts & susceptible Drawing up of epidemiological case sheets

Material and Methods (contd..) Advisory for no contact with patients in hospitals Aggressive control methods Blood samples for varicella antibodies Line listing of cases Vaccination of all susceptible Follow up of cases and contacts

Results Total of 8 cases occurred Total cadets in the institute were 156 64 students labelled as susceptible All susceptible students vaccinated. All cases were within the incubation period of the index case No second and third waves seen DNA isolation showed the causative org to be a wild strain Svl of pts and other staff in contact with trainees revealed no cases

Demographic and clinical characteristics of cases Demographic/clinical characteristics (n=8) Age, years ; mean (range) 19.87 years (18-22) Gender (% female) 8 (100%) 1st Symptom – Fever Rash Body ache 5 (62.5%) 2 (25%) 1 (12.5%) 6 (75%) Rash (Generalized) <50 in number 50-249 in number 3 (37.5%) Malaise 4 (50%) Complications Nil

Distribution of cases as per training batches

Percentages of students with history of chickenpox, vaccination & those susceptible to chickenpox

Epidemic Curve Index case reported on 23rd Nov with Peak of epidemic from 8th to 10th Dec as four cases were reported.

Summary This outbreak occurred among trainee health care workers (HCW) living in an institutional setting Potential of the outbreak spilling out of control and into patient facility. Aggressive control measures were instituted to include notification, isolation of cases and vaccination of susceptible No secondary waves occurred, the vaccine effectiveness can be considered high and vaccination as a control strategy very effective.

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