Eurosurveillance - Volume 14, Issue 6, 12 February 2009

In January 2009, the eleventh case of Lassa fever imported to the United Kingdom was diagnosed in London. Risk assessment of 328 healthcare contacts with potential direct exposure to Lassa virus - through contact with the case or exposure to bodily fluids - was undertaken. No contacts were assessed to be at high risk of infection and no secondary clinical cases identified.

Since the beginning of 2008, France has been experiencing a resurgence of measles. It started in a religious traditionalist group with low coverage and secondarily spread to the general population. This situation is the consequence of the insufficient vaccine coverage (less than 90 % at 24 months of age) which had led to the accumulation of susceptibles over the last years. More than 550 cases have been notified in 2008, the vast majority being unvaccinated. One measles-related death has occurred early 2009. Efforts to enhance communication to the general public and the health professionals on measles vaccination and control measures around cases are ongoing.

The Swedish National Board of Health and Welfare (NBH) decided that a vaccine that protects against cervical cancer caused by human papillomavirus (HPV) should be included in the childhood vaccination directive as a nationwide-programme targeting 12-year-old girls from 2010 as a part of the school-health programme. Currently, vaccination of girls 13-18 years of age is covered by the public insurance. In this paper we describe the decision-making process behind the introduction of HPV vaccination in Sweden.

Several countries plan to introduce non-contact infrared thermometers (NCIT) at international airports in order to detect febrile passengers, thus to delay the introduction of a novel influenza strain. We reviewed the existing studies on fever screening by NCIT to estimate their efficacy under the hypothesis of pandemic influenza. Three Severe Acute Respiratory Syndrome (SARS) or dengue fever interventions in airports were excluded because of insufficient information. Six fever screening studies in other gathering areas, mainly hospitals, were included (N= 176 to 72,327 persons; fever prevalence= 1.2% to 16.9%). Sensitivity varied from 4.0% to 89.6%, specificity from 75.4% to 99.6%, positive predictive value (PPV) from 0.9% to 76.0% and negative predictive value (NPV) from 86.1% to 99.7%. When we fixed fever prevalence at 1% in all studies to allow comparisons, the derived PPV varied from 3.5% to 65.4% and NPV was >=99%. The low PPV suggests limited efficacy of NCIT to detect symptomatic passengers at the early stages of a pandemic influenza, when fever prevalence among passengers would be =<1%. External factors can also impair the screening strategy: passengers can hide their symptoms or cross borders before symptoms occur. These limits should be considered when setting up border control measures to delay the pandemic progression.