Use of vaccination in a large outbreak of primary varicella in a detention setting for African immigrants.

BACKGROUND: Primary varicella (PV) presents a public health risk for adults in closed residential settings, especially for immigrants from tropical areas where infection during childhood is less likely. METHODS: In this study, an outbreak of PV at a detention facility for illegal immigrants from Eritrea and Sudan in southern Israel is described. Basic demographic information and clinical course for all cases were obtained. RESULTS: One hundred and nine cases of PV, all in young adult men aged 18-40 years, were diagnosed over a 7-month period (June to December 2012). Diagnosed patients were placed in quarantine until the resolution of illness without other public health measures being implemented. The Israeli Ministry of Health was notified of the outbreak in early December and recommended two doses of varicella vaccine for all susceptible detainees and staff. Within 2 weeks of completion of the first dose of vaccine, there was only one additional case in a detainee immunized 13 days prior to diagnosis. The effectiveness of vaccination in halting the outbreak was immediate, despite the fact that 15.6% of detainees refused to be immunized. CONCLUSIONS: The possible roles of vaccination or natural infection in achieving herd immunity and thereby ending the outbreak in this population are discussed. We recommend considering early vaccination for all when an outbreak or a series of connected cases is detected in a closed-residential setting such as the detention facility described here.

Adherence with oseltamivir chemoprophylaxis among workers exposed to poultry during avian influenza outbreaks in southern Israel.

OBJECTIVES: To determine adherence with recommended pre- and post-exposure oseltamivir prophylaxis (OP) among workers exposed to poultry during five simultaneous avian influenza (AI) H5N1 outbreaks in poultry farms in southern Israel in March 2006, as well as the efficiency of the distribution system of oseltamivir in the community. DESIGN: Epidemiological investigation identified 201 workers exposed to poultry during AI outbreaks. They were interviewed by a public health nurse regarding adherence with recommended OP, symptoms, and possible side effects. Data were collected on type of exposure, age, sex, rate of adherence with OP, and reasons for non-adherence. For eight workers, paired sera were drawn for the determination of antibodies to H5. Data were collected on the efficiency of the distribution of oseltamivir tablets to workers in the community. RESULTS: High adherence with OP (87.6%) was found among poultry workers during outbreaks of AI, with no difference by type of exposure, age, or sex. There was a low rate of side effects of OP (1.5%). No exposed workers developed AI and none of the eight who had paired sera drawn showed seroconversion. The distribution of OP in the community was inefficient, with 27.7% of the tablets 'lost' or returned unusable. CONCLUSIONS: These data emphasize the importance of developing efficient targeted distribution systems in the community for OP, in order to prevent human infection during AI outbreaks.