Genotype D4 Research Articles

Spotlight on measles 2010: An epidemiological overview of measles outbreaks in Poland in relation to the measles elimination goal

The objective of this study was to describe transmission chains of measles observed in Poland during 2008-2009. A decade ago, the incidence of measles in Poland declined and approached one case per million inhabitants one of the World Health Organization's criteria for measles elimination. Following a period of very few reported measles cases (2003 to 2005), an increase in incidence was observed in 2006. Since then, the incidence has constantly exceeded one case per million inhabitants. Of 214 measles cases reported in 2008 and 2009 in Poland, 164 (77%) were linked to 19 distinct outbreaks, with 79% of cases belonging to the Roma ethnic group. Outbreaks in the non-Roma Polish population had different dynamics compared to those in the Roma population. On average, measles outbreaks in Roma communities involved 10 individuals, seven of whom were unvaccinated, while outbreaks in the non-Roma Polish population involved five individuals, half of whom were incompletely vaccinated. The majority of outbreaks in Roma communities were related to importation of virus from the United Kingdom. In six outbreaks, the epidemiologic investigation was confirmed by identification of genotype D4 closely related to measles viruses detected in the United Kingdom and Germany. Our data indicate that Poland is approaching measles elimination, but measles virus circulation is still sustained in a vulnerable population. More efforts are needed to integrate the Roma ethnic group into the Polish healthcare system and innovative measures to reach vulnerable groups should be explored.

Co‐circulation of multiple measles virus genotypes during an epidemic in France in 2008

In 2008, measles reappeared in France in a series of outbreaks. During this period, 604 measles cases were reported to a routine surveillance system and 305 (50%) of these cases were then confirmed in the laboratory. To understand better the current epidemiological situation and the circulation of different measles strains, a phylogenetic characterization of 113 (19%) of the measles cases from these outbreaks was performed. All measles cases met the WHO clinical criteria and were confirmed either by laboratory detection of measles-specific IgM and/or by detection of the virus genome by polymerase chain reaction (PCR) and viral isolation. PCR products generated from blood, oral fluid, urine, or nasopharyngeal-swab samples were sequenced for molecular epidemiology studies. Phylogenetic analysis showed a co-circulation of genotypes D4 and D5 during the first measles outbreak in the city of Reims in early 2008. Over the course of the year, the A, B3.2, D8, and D9 genotypes also appeared. The data from this study show the simultaneous circulation of several measles genotypes in France and describe genotypes D8 and D9 for the first time in this country. The data also suggest that there are still many pockets of unvaccinated individuals helping to maintain the circulation of measles virus in the population. Phylogenetic studies allowed the corroboration of epidemiologic links and showed that nosocomial transmission can create significant risk for measles dissemination. Finally, the pattern of changes in viral genotypes during 2008 suggests a regular introduction of measles strains from abroad.

Brote de sarampión en Campo de Gibraltar, Cádiz, durante el período febrero-julio 2008

On the 4th of February 2008, 2 cases of measles, epidemiologically linked (2 members of the crew of the Fast-Ferry Jaime I from the company Balearia, which performs the route Algeciras-Tangier), were notified to the Epidemiological Surveillance Network in Andalusia (SVEA). The aim of this paper is to epidemiologically characterize this population level outbreak detected in the area of Campo de Gibraltar, the vaccine effectiveness and the control measures implemented. Descriptive observational study of reported cases. We have analysed the following variables: age, sex, municipality of residence, onset date, virus genotype, groups involved, previous immunization status, interventions, vaccine effectiveness. Information sources are SVEA records, vaccination program and individual digital story (Diraya). Rates 10(5) were calculated according to age group and frequency measurements. To compare vaccine effectiveness, the Chi(2) test was used. We confirmed 155 cases of measles, 88.4% by laboratory techniques. Most affected age groups under 2 years (19%) and from 21 to 40 (51%). The 54.2% male. The 72,14% were not vaccinated. Virus was isolated from imported measles genotype D4. The vaccine efficacy was greater than 99%. The outbreak of the imported measles virus was confirmed. More than half of the cases were not vaccinated. The decrease in the incidence in vaccinated individuals recommends the necessity of carrying out Catch-Up campaigns to increase the coverage therefore avoiding the appearance of these outbreaks.

Features of a Measles Outbreak in the Elimination Era~!2009-11-20~!2009-11-25~!2010-02-16~!

In 2000, the circulation of indigenous measles was interrupted in Catalonia as a result of the activities of the elimination programme introduced in 1991. However, various transmission chains occurred in the indigenous population after the introduction of an imported case, and this caused a total change in the existing situation of elimination. The objective of this study was to analyze the epidemiological and clinical characteristics of the measles outbreak in Catalonia in 2006. Cases reported between August 28 2006 and July 8 2007 were collected. Cases were microbiologically confirmed by determination of measles-specific IgM and/or detection of the viral genome in urine samples. A total of 381 cases of measles were confirmed, representing an incidence of 6.6 per 100,000 inhabitants. Laboratory confirmation was made in 87.1% of the cases and all specimens sequenced belonged to the D4 genotype. A total of 89.5% of the cases occurred in non-vaccinated people, above all in infants aged <16 months.

Measles Outbreak, the Netherlands, 2008

Measles Outbreak, the Netherlands, 2008

Hepatitis E virus (HEV) genotype and the prevalence of anti-HEV in 8 species of animals in the suburbs of Beijing

To investigate the prevalence of anti-hepatitis E virus (HEV) and genotypes of hepatitis E virus in 8 species of animals including swine, cattle, sheep, horse, donkey, dog, chicken and duck in the suburb of Beijing. Serum samples were collected from the 8 species of animals, and fecal samples of younger swine were collected from 2 stock farms. Anti-HEV was detected by Double Antigen Sandwich Assay. HEV RNA from fecal samples was detected by a reverse transcription nested polymerase chain reaction (RT-nPCR). Parts of the PCR products were cloned and sequenced. The swine HEV sequences were analyzed genetically. The positive rates of anti-HEV in serum specimens of swine, cattle, horse, donkey, sheep, dog, duck and chicken were 80.43% (481/598), 15.02% (52/346), 14.29% (40/280), 0 (0/26), 9.88% (33/334), 0 (0/21), 3.03% (7/231) and 2.53% (8/316), respectively. The anti-HEV prevalence of adult swine (>/= 6 months) and younger swine ( < / = 3 months) were 87.86% (369/420) and 62.92% (112/178) respectively. 74 of 111 (66.67%) pig faces were positive for HEV RNA. Sequence analysis on these positive samples showed that there were 6 groups of HEV designated as bjsw1, bjsw2, bjsw3, bjsw4, bjsw5 and bjsw6. The 6 strains of HEV shared 94.5% - 99.6% sequence identity of partial HEV ORF2 nucleotide with each other. The identities of HEV ORF2 nucleotide sequences between the 6 strains and genotype 1, 2, 3 and 4 were 75.6% - 78.6%, 75.6% - 76.2%, 77.1% - 80.7% and 83.7% - 94.5%, respectively. The sequence identity between the 6 strains and human HEV genotype 4d was 90.0% - 94.5%. HEV infection was seen in swine, cattle, horse, sheep, duck and chicken in the suburbs of Beijing. The anti-HEV positive rate appeared the highest in swine and the lowest in dog and donkey. The six strains of HEV isolated from younger swine belonged to genotype 4d.

A 16-year old male with cortical blindness and focal motor seizures

A 16-year old male with cortical blindness and focal motor seizures

Molecular evolution of measles viruses circulated in Taiwan 1992-2008

Genetic analyses of viral samples from 74 laboratory confirmed measles cases occurring in Taiwan during 1992-2008 identified six viral genotypes D3, D5, D9, G2, H1 and H2. The most frequently detected genotype, H1, was associated with outbreaks in 1994 and 2002, and was the likely indigenous genotype in 1992. In response to the outbreaks, two catch-up campaigns were launched and a routine second dose of measles, mumps, and rubella vaccine at entry to elementary school was introduced. The vaccination campaigns successfully reduced the number of measles cases in Taiwan, and many of the more recent cases can be traced to importations, primarily from other Asian countries. A number of measles genotypes which were associated with outbreaks in other Asian countries were detected among the more recent cases. The more recent genotype H1 viruses had sequences that were identical to those currently circulating in China or associated with international importation of virus.

Fulminant hepatitis failure in adults and children from a Public Hospital in Rio de Janeiro, Brazil

Fulminant hepatic failure (FHF) is characterized by massive hepatocellular injury, whose physiopathology is still unclear. Hepatitis B (HBV) is probably the most common viral cause of FHF, while hepatitis A (HAV) virus seem occurs less frequently. However, the host and viral factors that determine the outcome of these infections are poorly understood. In the present study, viral load and genotyping determining regions of HAV and HBV genomes were sequenced. Eight FHF patients and one patient with severe acute hepatitis (SAH) were included. Liver and blood samples were collected during liver transplantation or necropsy procedures. HAV-RNA and HBV-DNA were extracted from serum, biopsy and paraffin liver. Nucleotide sequencing of HAV-RNA was performed from VP1/2A and HBV-DNA from PreS/S region. The amplified samples were quantified by Real-Time PCR. The cases of HAV infection were due to subgenotype IA. The cases of HBV infection were due to genotype A2 and D4. The case of HAV/HBV coinfection was infected by genotype IA and D3. Hepatitis A and B infection were associated with genotypes most prevalent in Brazil. In hepatitis A infection the mean of period evolution was 13 days. In hepatitis B, FHF patients infected by genotype D have a shorter period of evolution than FHF patients infected by genotype A (mean 15 v. 53 days). There was no association with genotype-determining region with the severity of hepatitis, however nucleotide differences and high viral load could be observed among FHF.

Serum 25-Hydroxyvitamin D3 Levels Are Associated With Breslow Thickness at Presentation and Survival From Melanoma

A cohort study was carried out to test the hypothesis that higher vitamin D levels reduce the risk of relapse from melanoma. A pilot retrospective study of 271 patients with melanoma suggested that vitamin D may protect against recurrence of melanoma. We tested these findings in a survival analysis in a cohort of 872 patients recruited to the Leeds Melanoma Cohort (median follow-up, 4.7 years). In the retrospective study, self-reports of taking vitamin D supplements were nonsignificantly correlated with a reduced risk of melanoma relapse (odds ratio = 0.6; 95% CI, 0.4 to 1.1; P = .09). Nonrelapsers had higher mean 25-hydroxyvitamin D(3) levels than relapsers (49 v 46 nmol/L; P = .3; not statistically significant). In the cohort (prospective) study, higher 25-hydroxyvitamin D(3) levels were associated with lower Breslow thickness at diagnosis (P = .002) and were independently protective of relapse and death: the hazard ratio for relapse-free survival (RFS) was 0.79 (95% CI, 0.64 to 0.96; P = .01) for a 20 nmol/L increase in serum level. There was evidence of interaction between the vitamin D receptor (VDR) BsmI genotype and serum 25-hydroxyvitamin D(3) levels on RFS. Results from the retrospective study were consistent with a role for vitamin D in melanoma outcome. The cohort study tests this hypothesis, providing evidence that higher 25-hydroxyvitamin D(3) levels, at diagnosis, are associated with both thinner tumors and better survival from melanoma, independent of Breslow thickness. Patients with melanoma, and those at high risk of melanoma, should seek to ensure vitamin D sufficiency. Additional studies are needed to establish optimal serum levels for patients with melanoma.

Measles outbreak linked to a minority group in Austria, 2008

We report on a measles outbreak originating in an anthroposophic community in Austria, 2008. A total of 394 (94.9%) cases fulfilled the outbreak case definition including 168 cases affiliated to the anthroposophic community. The source case was a school pupil from Switzerland. The Austrian outbreak strain was genotype D5, indistinguishable from the Swiss outbreak strain. A school-based retrospective cohort study in the anthroposophic school demonstrated a vaccine effectiveness of 97.3% in pupils who had received a single dose of measles-containing vaccine and 100% in those who had received two doses. The vaccination coverage of the cases in the anthroposophic community was 0.6%. Of the 226 outbreak cases not belonging to the anthroposophic community, the 10-24 years age group was the most affected. Our findings underline the epidemiological significance of suboptimal vaccination coverage in anthroposophic communities and in older age groups of the general population in facilitating measles virus circulation. The findings of this outbreak investigation suggest that the WHO European Region is unlikely to achieve its 2010 target for measles and rubella elimination.

Measles viruses of genotype H1 evade recognition by vaccine-induced neutralizing antibodies targeting the linear haemagglutinin noose epitope

The linear haemagglutinin noose epitope (HNE; aa 379-410) is a protective B-cell epitope and considered to be highly conserved in both the vaccine and the wild-type measles virus (MeV) haemagglutinin (H) proteins. Vaccine virus-derived monoclonal antibodies (mAbs) BH6 and BH216, which target the HNE, neutralized MeVs of genotypes B3, C2, D4, D5, D6, D7 and D8, and the vaccine strain Edmonston Zagreb. In the case of genotype H1, only strain Berlin.DEU/44.01 was neutralized by these mAbs, whereas strains Shenyang.CHN/22.99 and Sofia.BGR/19.05 were not. The H gene sequences of these two strains showed an exchange of proline 397 (P397) to leucine (L397). Mutated H proteins, with P397 exchanged to L and vice versa, were compared with original H proteins by indirect fluorescence assay. H proteins exhibiting P397 but not those with L397 were recognized by BH6 and BH216. This indicates that L397 leads to the loss of the neutralizing HNE. In contrast, human sera obtained from vaccinees (n=10) did not discriminate between genotype H1 variants P397 and L397. This concurs with the epidemiological observation that the live-attenuated vaccine protects against both H1 variants. Furthermore, we demonstrated that MeVs of genotype H1 also lack the neutralizing epitopes defined by the vaccine virus-induced mAbs BH15, BH125 and BH47. The loss of several neutralizing epitopes, as shown for H1 viruses currently circulating endemically in Asia, implies that epitope monitoring should be considered to be included in measles surveillance.

Genetic variability of wild-type measles viruses, circulating in the Russian Federation during the implementation of the National Measles Elimination Program, 2003–2007

Genetic characterization of wild-type measles viruses (MVs) is an important component of laboratory surveillance of measles. In this study, a phylogenetic analysis was performed of the nucleoprotein gene sequences of 228 MVs isolated in the Russian Federation between 2003 and 2007. Five genotypes, D4, D5, D6, D8, and H1, were detected. From 1999 through the first 6 months of 2003, the most prevalent genotype in the European part of Russia was D4. All genotype D4-type viruses were closely related to each other (with overall sequence diversity of ≤0.9%), suggesting the presence of a single endemic MV strain. After 2003, viruses with closely related sequences within genotype D6 (£0.9% sequence diversity) were prevalent. During this time, there was a low level of indigenous transmission of genotype D6, and genotype D6 viruses were imported from neighbouring countries, which led to the identification of two lineages of genotype D6, i.e. D6a and D6b. Lineage D6a was closely related to viruses isolated in Turkey, Kazakhstan, and Uzbekistan, whereas lineage D6b was linked to a large outbreak in Ukraine in 2005–2006. Genotypes H1, D5 and D8 were associated with sporadic cases and clusters of transmission linked to importations. Enhanced vaccination interrupted the transmission of the previous endemic lineage D4 in 2003 and of lineage D6a in 2005, although an accumulation of susceptible individuals in the population allowed for prolonged circulation of lineage D6b. These data on MV genotype distribution, in conjunction with the epidemiological data for measles, show considerable progress in measles control and suggest that regional elimination is possible.

Epidemiological and Molecular Studies of Measles at Different Clusters in Hokkaido District, Japan, 2007

In 2007 eight epidemic clusters (more than 15 cases in each) and other sporadic cases of measles occurred in Hokkaido district, Japan. A total of 850 cases were identified. Approximately half of them were ≥15 years of age, resulting in a huge public health problem in the community associated with school closings, and 31% of the cases reported that they already had a history of vaccination. Of 28 isolates of the measles virus detected, all were identified as genotype D5, identical to the type isolated in other areas of Japan, suggesting that a highly homologous measles virus circulated in Japan. The occurrence pattern of measles patients and molecular epidemiology indicated that the measles virus that spread in Hokkaido district might not be indigenous.

Serum vitamin D levels, VDR, and survival from melanoma

9016 Background: Vitamin D has pleiotropic effects, which may moderate the interaction between patients and their tumors. Two studies were carried out to test the hypothesis that higher vitamin D levels reduce the risk of relapse from melanoma. Methods: A pilot retrospective case-control study in 271 melanoma patients suggested that vitamin D may protect against recurrence of melanoma. We then tested these findings in a survival analysis in a cohort of 872 cases recruited to the Leeds Melanoma Cohort (median follow up of 4.7 years). Results: Pilot study Results suggested that taking vitamin D reduced the risk of relapse from melanoma (OR 0.6, 95% CI: 0.4, 1.1). Non-relapsers had higher mean 25-dihydroxyvitamin D3 levels than relapsers (49 nmol/L compared with 46, p=0.3). Cohort study Higher 25-dihydroxyvitamin D3 levels were associated with lower Breslow thickness at diagnosis and were independently protective of relapse and death: hazard ratio (HR) for relapse free survival (RFS) 0.76, 95% CI: (0.64, 0.96), for a 20nmol/L increase in serum level. There was evidence of interaction between the vitamin D receptor (VDR) BsmI genotype and serum 25-dihydroxyvitamin D3 levels on RFS. Conclusions: The pilot study provided preliminary evidence for a role for vitamin D in outcome from melanoma. The cohort study provided further evidence that higher 25-dihydroxyvitamin D3 levels, at diagnosis, were associated both with thinner tumors and better survival, independent of Breslow thickness, from melanoma. Melanoma patients should avoid vitamin D deficiency. Further studies are needed to establish optimal serum levels for melanoma patients. No significant financial relationships to disclose.

Hepatitis B virus genotypes and hepatitis B surface antigen mutations in family contacts of hepatitis B virus infected patients with occult hepatitis B virus infection

The association and profile of surface gene mutations with viral genotypes have been studied in patients with chronic hepatitis B virus (HBV) but not in subjects with occult HBV infection. This study aimed to investigate the association of surface gene mutations with viral genotypes in occult HBV infection. Of 293 family contacts of 90 chronic HBV index patients, 110 consented for the study. Of 110 subjects, 97 were hepatitis B surface antigen (HBsAg) negative. HBV genotyping was done using direct DNA sequencing. The S-gene was also sequenced in 13 chronic hepatitis B patients to serve as controls. Twenty-eight (28.8%) of the 97 subjects had occult HBV infection. Bidirectional sequencing of partial S-gene was successful in 13 of them. Seven (53.8%) of the viral sequences are genotype A1, two (15.3%) each having genotypes D5&D2 and one each (7.6%) having D1&G genotypes. Seven (53.8%) of the 13 HBsAg positive patients, had genotype D&6 (46.1%) genotype A. A128V & T143M mutations were observed in 5 of 13 (38.4%) subjects and A128V & P127S in 2 of 13 (15.3%) patients (P = 0.385). A128V mutation was seen in two (15.3%) subjects with D2 genotype, while T143M mutation was seen in three (23.07%) subjects with A1genotype. At aa125, three (23.07%) subjects with D5 genotype had methionine instead of threonine. There were wild type sequences in five (38.4%) subjects, one each of D1, G genotypes (20%) and four A1 (80%) genotypes. None of the subjects had G145R mutation. Occult HBV infection may be common in household contacts of chronic HBV infected patients. Equal prevalence of A&D sub-genotypes was present in occult HBV subjects and in chronic HBV patients. Mutations of the S-gene are genotype specific in both occult as well as chronic HBV infection.

Genetic Identification and Phylogenetic Analysis of Anaplasma and Ehrlichia Species in Haemaphysalis longicornis Collected from Jeju Island, Korea

A total of 1,395 Haemaphysalis longicornis ticks collected from Jeju Island of Korea were examined by 16S rRNA gene-based nested PCR for the presence of infection with Anaplasma and Ehrlichia species. Template DNAs to detect the tick-borne pathogens were prepared from a total 506 tick pools. Eight genera of Anaplasma and six Ehrlichia by 16S rRNA gene PCR and sequencing analysis were identified. A. phagocytophilum was the most prevalent (27 [1.9%]) by nested PCR, followed by A. bovis (5 [0.4%]), E. chaffeensis (4 [0.2%]), and A. centrale (1 [0.1%]). In the phylogenetic analysis based on 16S rRNA sequences, eight genera of Anaplasma group (> 99.4% homology) and six Ehrlichia group (> 99.5% homology) were close to deposited A. marginale strains (AF309867, AF414874, and FJ226454) and Ehrlichia sp. (DQ324547), respectively. Three Anaplasma species groups A. phagocytophilum (group A), A. bovis (group B), and A. centrale (group C) and one Ehrlichia species E. chaffeensis (group D) were determined by comparing with Anaplasma and Ehrlichia related sequences. First, twenty-eight A. phagocytophilum clones belonging to group A were divided into 7 genotypes. The sequence similarity among genotypes A1 to A4 was very high (> 99.6%). Genotype B2 was close to A. bovis from Korea (99.7%). Genotype D1 was close to known E. chaffeensis strains (M73222, AF147752, and AY350424) and their similarity value was 99.7%. In conclusion, the genera of Anaplasma/Ehrlichia, A. phagocytophilum, and E. chaffeensis identified in predominant H. longicornis ticks were ubiquitous throughout the Jeju Island. The various native groups have been found through sequence identities and phylogenetic analysis.

Molecular epidemiology of circulating measles virus in Ireland 2002–2007

The molecular characterization of measles virus (MeV) is a valuable epidemiological tool to monitor virus transmission and to discriminate between imported and endemic infection. There has been significant immigration into Ireland in recent years and many individuals originate from regions of high measles incidence. Ireland has had a number of outbreaks of MeV which appear attributable to sub-optimal vaccine uptake and possibly imported strains as new genotypes have been identified in recent years. To ascertain any significant changes in circulating measles genotypes we investigated 65 confirmed measles cases between the years 2002 and 2007. The laboratory diagnosis of measles was confirmed by detection of measles-specific IgM in oral fluid in conjunction with a real-time polymerase chain reaction assay targeting the MeV hemagglutinin gene. Phylogenetic analysis based on the 3' hypervariable region of the nucleoprotein gene was performed and three genotypes, all within measles clade D, were found to be circulating during this time period. In 2002 and 2003, genotype D8 (n = 2) was observed whereas genotype D7 was dominant in 2003 (n = 31). A distinct change in the circulating MeV genotype and increased genetic diversity was observed between 2004 and 2007. All cases were within genotype D4 (n = 32) but were phylogenetically distinct from each other. These data provide important epidemiologic baseline information on MeV in Ireland and facilitates detailed examination of measles transmission.

Abstract B82: First report of genotype F and novel mutations in the core promoter region of HBV isolates from a northern Indian population

Abstract B82 Hepatitis B virus (HBV) isolates (35) from North India having different stages of hepatitis were studied for genotypes distribution, core promoter mutations and phylogenetic origin. Assays of SGOT, SGPT and HBeAg were performed in all samples using commercial available kits. Genotypes were determined in all the studied subjects by restriction fragment length polymorphism and core promoter mutations by direct sequencing of PCR products. HBV genotype D was found in 57% of the isolates while 40 % isolates have genotype A and 3% have genotype F. This is the first report of genotype F in Indian population. Earlier it was reported from population from Japan, USA, Argenita and Venezuela. Subgenotype D 1 was predominant among genotype D isolates followed by genotype D2 and D6. Subgenotype A1 was predominant among genotype A followed by A3. Genotype F has subgenotype F2. 1762A -T and 1764G-A mutations were observed in 50% isolates having active viral replication of HBV virus. These are also present in the sera of HCC patients. Wild types were observed in many asymptomatic patients. Novel mutations like 1697G 1698C1727A 1740T were observed in the 50% isolates having nearly normal or slightly high ALT/AST level and all the samples were positive for HBeAg. 1811C 1812C1813T mutations were observed in 15% isolates with slightly high ALT/AST level. 1858T was observed in genotype D with HBeAg positive. 1898A stop codon mutations responsible for HBeAg negativity as observed in Japanese, South African and other world populations could not be observed in the isolates under study. Phylogenetic tree of HBV isolates based on the precore/core gene sequences was drawn with HBV sequences from other parts of the world and previously reported Indian strains from eastern part. Majority of strains shows a high degree of closeness with Chinese and eastern Indian strains. Two rare sequences having nearly 46% and 26% difference in the nucleotide sequence with the available wild type with respect to the CP region were also observed. Efforts are going on to amplify the genotype F to full length. The studies regarding mutations, their role in disease progression and potential as biomarkers of hepatitis B is actively underway. Citation Information: Cancer Prev Res 2008;1(7 Suppl):B82.

Large Outbreak of Measles in a Community with High Vaccination Coverage: Implications for the Vaccination Schedule

Attempts to eliminate measles from a country or region may be disrupted by an imported case that affects indigenous persons. The objective of this study was to analyze epidemiological and clinical characteristics of a measles outbreak in Catalonia, Spain, in 2006. Data on cases of measles reported to the Department of Health, Generalitat of Catalonia, during the period 28 August 2006 through 8 July 2007 were collected. Suspected cases were confirmed by determination of measles-specific immunoglobulin M antibodies and/or detection of virus genome. Incidences were calculated using the estimated population of Catalonia for 2006, and 95% confidence intervals were determined assuming a Poisson distribution. The association between proportions was determined using the chi(2) test and Fisher's exact test. The level of statistical significance was set at alpha = .05. A total of 381 cases were confirmed, for an incidence of 6.6 cases per 100,000 persons. A total of 89.5% of cases occurred in nonvaccinated persons, mainly those aged < or =15 months (incidence, 278.2 cases per 100,000 persons; mean age of patients, 12 months). Indigenous subjects accounted for 89.8% of cases, and laboratory confirmation of results was obtained for 87.1%. Measles genotype D4 was identified in all sequenced samples. The age distribution of cases of measles among children aged <15 months suggests that the first dose of vaccine should be routinely administered at the age of 12 months.