Eurosurveillance - Volume 15, Issue 30, 29 July 2010

A measles outbreak (126 reported cases to date) has been ongoing in Greece, since January 2010, originally related to the recent outbreak in Bulgaria. Cases are mostly unvaccinated, and mainly belong to three groups: Roma population of Bulgarian nationality, Greek Roma population, and Greek non-minority population. In these population groups, 67%, 95%, and 25% of cases respectively were children aged 0-14 years. Measures were taken to raise clinical awareness, and vaccination of specific population groups was undertaken. Policies are necessary to increase routine vaccination uptake of hard-to-reach groups.

The emergence of the 2009 pandemic influenza A(H1N1) virus in North America and its subsequent global spread highlights the public health need for early warning of infectious disease outbreaks. Event-based biosurveillance, based on local- and regional-level Internet media reports, is one approach to early warning as well as to situational awareness. This study analyses media reports in Mexico collected by the Argus biosurveillance system between 1 October 2007 and 31 May 2009. Results from Mexico are compared with the United States and Canadian media reports obtained from the HealthMap system. A significant increase in reporting frequency of respiratory disease in Mexico during the 2008-9 influenza season relative to that of 2007-8 was observed (p<0.0001). The timing of events, based on media reports, suggests that respiratory disease was prevalent in parts of Mexico, and was reported as unusual, much earlier than the microbiological identification of the pandemic virus. Such observations suggest that abnormal respiratory disease frequency and severity was occurring in Mexico throughout the winter of 2008-2009, though its connection to the emergence of the 2009 pandemic influenza A(H1N1) virus remains unclear. .

The extent of the H1N1 pandemic has been estimated from case counts and deaths but the proportion of exposed populations with inapparent infections has not been described in detail. We analysed haemagglutination-inhibition (HI) antibody titres of pre-vaccination sera from pandemic vaccine trials conducted in six countries on four continents to provide an indication of A/CA/07/2009(H1N1)-like influenza seroprevalence in those populations. Among 7,962 subjects, ranging in age from 12 months to over 60 years, the proportions with HI antibody titres ≥40 to the H1N1pnd virus in the period from August to October 2009 were, by country: Costa Rica 26.4%, United States (US) 22.5%, Switzerland 16.9%, Germany 12.6%, Belgium 10.1%, and Japan 5.9%. Age-specific seropositivity rates in the samples were higher in children and adolescents in Costa Rica and in the US than in Europe and in Japan. The low proportion of seropositive children in Europe and Japan suggests that little local viral transmission had occurred in those regions even as late as September and October 2009, while in the US and Costa Rica, the greater proportion of previously infected children and young adults suggested that a significant number of asymptomatic infections had occurred during the first pandemic wave. Nevertheless, in all locations, the majority of the population remained susceptible to the pandemic virus at the beginning of the influenza season in the northern hemisphere, justifying the implementation of public health interventions.

Brucellosis is a global zoonotic disease, endemic in North African countries and around the Mediterranean. A prospective study of Brucella seroprevalence was conducted in north-western Libya (western mountains region). Blood samples collected over 13 months in the period December 2006 to January 2008 from 561 animals (goats, sheep, cattle and camels) and 546 human volunteers were tested for Brucella using the Rose Bengal test, tube agglutination test and ELISA assays. Amongst livestock, 31% of goats and 42% of cattle were seropositive. Human samples showed a high seropositivity of 40%, with 95 (43%) of the 221 positive samples positive for IgM, indicating active or recent infection. Control measures are needed to reduce this high prevalence of brucellosis in Libya.

This report outlines selected highlights of presentations that took place at the 2010 International Conference on Emerging Infectious Diseases (ICEID) [1], held between 11 and 14 July 2010 at the Hyatt Regency Atlanta in Atlanta, Georgia, United States (US). The conference was organised by five national and international bodies and was attended by over 1,600 participants from a wide range of professional backgrounds. Abstracts for the posters and slide sessions have been published [2].