Description of two measles outbreaks in the Lazio Region, Italy (2006-2007). Importance of pockets of low vaccine coverage in sustaining the infection

<p>Abstract</p> <p>Background</p> <p>Despite the launch of the national plan for measles elimination, in Italy, immunization coverage remains suboptimal and outbreaks continue to occur. Two measles outbreaks, occurred in Lazio region during 2006-2007, were investigated to identify sources of infection, transmission routes, and assess operational implications for elimination of the disease.</p> <p>Methods</p> <p>Data were obtained from several sources, the routine infectious diseases surveillance system, field epidemiological investigations, and molecular genotyping of virus by the national reference laboratory.</p> <p>Results</p> <p>Overall 449 cases were reported, sustained by two different stereotypes overlapping for few months. Serotype D4 was likely imported from Romania by a Roma/Sinti family and subsequently spread to the rest of the population. Serotype B3 was responsible for the second outbreak which started in a secondary school. Pockets of low vaccine coverage individuals (Roma/Sinti communities, high school students) facilitated the reintroduction of serotypes not endemic in Italy and facilitated the measles infection to spread.</p> <p>Conclusions</p> <p>Communities with low vaccine coverage represent a more serious public health threat than do sporadic susceptible individuals. The successful elimination of measles will require additional efforts to immunize low vaccine coverage population groups, including hard-to-reach individuals, adolescents, and young adults. An enhanced surveillance systems, which includes viral genotyping to document chains of transmission, is an essential tool for evaluating strategy to control and eliminate measles</p

Ecological and genetic analysis of copper and streptomycin resistance in Pseudomonas syringae pv. syringae

Strains of Pseudomonas syringae pv. syringae resistant to copper, streptomycin, or both compounds were recovered from symptomless and diseased tissue of four woody hosts in three nurseries in Oklahoma. In strains resistant to copper and streptomycin (Cu^r Sm^r), resistance to both compounds was cotransferred with a single plasmid which was either 68, 190, or 220 kilobase pairs (kb). All Cu^s Sm^r strains contained a 68-kb conjugative plasmid. Cu^r Sm^s, strains contained one plasmid which varied in size from 60 to 73 kb. All conjugative plasmids which transferred streptomycin resistance contained sequences homologous to the strA and strB Sm^r genes from the broad-host-range plasmid RSF1010. The Sm^r determinant was subsequently cloned from a 68-kb Cu^r Sm^r plasmid designated pPSR1. A restriction map detailing the organization of the homologous Sm^r genes from pPSR1 and RSF1010 and cloned Sm^r genes from P. syringae pv. papulans and Xanthomonas campestris pv. vesicatoria revealed the conservation of all sites studied. The Cu^r genes cloned from P. syringae pv. tomato PT23 and X. campestris pv. vesicatoria XV10 did not hybridize to the Cu^r plasmids identified in the present study, indicating that copper resistance in these P. syringae pv. syringae strains may be conferred by a distinct genetic determinant.Peer reviewedPlant Patholog