[A high school measles outbreak--control measures and vaccine efficacy].

Epidemiological investigation of a March 2007 detected measles outbreak of 28 cases in a 792-student high school in Tokyo. Students with a vaccination history had significantly milder symptoms than those without, and no cases occurred among students having two of measles vaccine in two doses of measles vaccine in their childhood. Vaccine efficacy (VE) calculated in our investigation was 93.9% (95% CI:87-97), and no significant difference was observed in vaccine type or manufacturer product. Students and parents were extremely difficult to persuade to cooperate in control measures such as emergency vaccination and home isolation through notification letters even during outbreaks. Schools should thus develop measles outbreak preparedness and response plans and identify potentially susceptible students in advance through documented proof of case histories and MCV vaccination. Outbreaks should promote early detection of patients and emergency vaccination targetting potentially susceptible students backed through close cooperation with medical facilities, education institutions, and the public health sector, together with school closures as appropriate.

[Utility of QuantiFERON TB-2G for tuberculosis contact investigations in public health services].

OBJECTIVE: The objective of the present study was to examine the utility of QuantiFERON TB-2G (QFT) in tuberculosis contact investigations performed by a public health center. METHODS: Adachi City Public Health Center, Tokyo, started using QFT in its laboratory service in June, 2005. The results of QFT, as well as tuberculin skin tests (TSTs) performed in tuberculosis contact investigations in the 10 month period since then were here analyzed. QFT was carried out for 67 contacts two months after their last contact with the index case. TST was given simultaneously. RESULTS: Of the total of 67 contacts investigated during the period, 9 were positive for QFT, 5 were doubtful positive, and the remaining 53 were negative. Among 48 subjects tested with TST, 22 had strong reactions with erythema > or = 30 mm, out of which 4 were positive for QFT. In addition, there were 5 QFT-positives among the remaining 26 with weak tuberculin reactions. These 9 subjects with positive QFT were indicated for chemoprophylaxis. CONCLUSIONS: Adachi City Public Health Center is pioneering the application of new technology for detection of latent tuberculosis infection in contact investigations of the inhabitants. As expected from trial findings, QFT was shown to be a useful tool in a practical setting for the purpose of detecting TB infection, with greater accuracy than with TST, independent of the history of BCG vaccination. This approach can help avoid both over-diagnosis and under-diagnosis.