Factors associated with differences between conventional contact tracing and molecular epidemiology in study of tuberculosis transmission and analysis in the city of Barcelona, Spain.

The aim of this study was to analyze the factors associated with conventional contact tracing (CCT) and molecular epidemiology (ME) methods in assessing tuberculosis (TB) transmission, comparing the populations studied and the epidemiological links established by both methods. Data were obtained from TB case and CCT registries, and ME was performed using IS6110-based restriction fragment length polymorphism (RFLP) analysis and mycobacterial interspersed repetitive unit 12 (MIRU12) typing as a secondary typing method. During two years (2003 and 2004), 892 cases of TB were reported, of which 687 (77%) were confirmed by culture. RFLP analysis was performed with 463 (67.4%) of the 687 isolated strains, and MIRU12 types in 75 strains were evaluated; 280 strains (60.5%) had a unique RFLP pattern, and 183 (39.5%) shared patterns, grouping into 65 clusters. CCT of 613 (68.7%) of 892 cases detected 44 clusters involving 101 patients. The results of both CCT and ME methods yielded 96 clusters involving 255 patients. The household link was the one most frequently identified by CCT (corresponding to 80.7% of the cases clustered by this method), whereas nonhousehold and unknown links were associated with 94.1% of the strains clustered by ME. When both methods were used in 351 cases (39.3%), they showed the same results in 214 cases (61%). Of the remainder, 106 (30.2%) were clustered only by ME, 19 (5.5%) were clustered only by CCT, and 12 (3.4%) were clustered by both methods but into different clusters. Patients with factors potentially associated with social problems were less frequently studied by CCT (P = 0.002), whereas patients of <15 years of age, most with negative cultures, were less frequently studied by ME (P = 0.005). Significant differences in the populations studied by ME versus CCT were observed, possibly explaining the scarce correlation found between the results of these methods. Moreover, ME allowed the detection of nonhousehold contact relationships, whereas CCT was more useful for tracing transmission chains involving patients of <15 years of age. In conclusion, the two methods are complementary, suggesting the need to improve the methodology of contact study protocols.

[Evaluation of mass vaccination programmes: the experience of Hepatitis A in Catalonia]. / Evaluación del impacto de los programas de vacunación masiva: la experiencia de la hepatitis A en Cataluña.

BACKGROUND: The hepatitis A + B vaccination programme of preadolescents was introduced in 1998 in Catalonia. During the following years, one of the main objectives has been to quantify the reduction in the incidence of hepatitis A caused by the vaccination programme. METHODS: A retrospective analysis applying the space-time scan statistic to reported incidence rates of hepatitis A was carried out in the counties of Catalonia from 1992 to 2007. The relative risk (RR) was calculated and the spatial autocorrelation was estimated using Moran's I statistic. RESULTS: Six of the 7 space-time clusters identified by the scan statistic occurred in the pre-vaccine era (1992-1998) and only one in the post-vaccine era (1992-2007). In the first 10 four-weekly periods of the post-vaccine era (1999-2005) there was a significant reduction in the incidence of hepatitis A in Catalonia with respect to the pre-vaccine era (1992-1998) (p<0,01). CONCLUSIONS: Moran's I statistic showed no pattern of global spatial dependence and was useful in detecting local clusters. These results corroborate previous studies that attributed most of the reduction in the incidence of hepatitis A in Catalonia to the effect of vaccination.

[Recommendations for health research and information on definitions and variables for the study of the foreign-born immigrant population]. / Recomendaciones para la investigación e información en salud sobre definiciones y variables para el estudio de la población inmigrante de origen extranjero.

BACKGROUND: The growth of the foreign population residing in Spain makes it necessary to avail of better information on the level of health. In the health information and research systems, no uniform criteria currently exist for the nomenclature of origin-related variables. This study poses a consensus on the definitions of immigrant and foreigner. METHODS: Employing the Delphi methodology, 66 experts in immigration from different disciplines were invited to take part in the study using a two-round questionnaire with suggested definitions, terms and variables, including in the second round the percentages of responses and the comments made by the participants in the first. The suggestions regarding which an 80% consensus was reached were put into a final document which was approved in the third round. RESULTS: A total of 57 people accepted the invitation, 44 having completed at least one round and 33 having completed all three. Some of the most important aspects regarding which a consensus was reached were: the term "immigrant" denotes the individual who comes to a country where he/she was not born to take up residency, one not being an immigrant on a lifelong basis. Those individuals born in another country who have arrived in Spain less than 5-10 years ago can be considered immigrants; and immigrated people are all those individuals born in another country. Socioeconomic variables, gender, administrative status and country of origin should also be taken into consideration. The children of immigrated individuals who are born in Spain must not be considered individuals who are born in Spain must not be considered. CONCLUSIONS: To properly define the inmigrating and immigrated population categories, the health studies and information systems must include country of birth, year of arrival and nationality.

Prevalence of tinea capitis and tinea pedis in Barcelona schoolchildren.

BACKGROUND: Although dermatophytoses can appear at any age, some types are particularly prevalent in children. There are no prior data on the prevalence of tinea capitis and tinea pedis in Barcelona, Spain. To identify the prevalence of tinea in school children in the area with the highest immigrant population in this city, a cross-sectional study was performed. A second objective was to identify the etiologic agent to study the possibility of the introduction of foreign dermatophyte species and to evaluate the possibility of encountering healthy hosts. METHODS: From October 2002 until June 2003, we evaluated 1305 schoolchildren, ages 3-15 years, belonging to 21 schools located in the inner city of Barcelona to determine the prevalence of tinea capitis and pedis in school children. Cultures of scalp and feet were done in each child. RESULTS: 36(2.8%) children had tinea pedis and 3 (0.23%) had tinea capitis. One child had tinea capitis and tinea pedis, caused by different species (t. capitis caused by Trichophyton mentagrophytes and tinea pedis caused by Trichophyton rubrum). Of the 39 positive cases for dermatophytes, the etiologic agent in 18 (46.1%) was T. mentagrophytes, 17 (43.5%) T. rubrum, 2 (5.5%) Epidermophyton floccosum and 2 (5.5%) Trichophyton tonsurans. Of these 39 cases of tinea, 15 (38.5%) were Spanish natives and 22 (56.4%) were immigrants. CONCLUSION: The prevalence of tinea capitis was lower that we had expected, and it was noted that there was a greater prevalence of tinea pedis among schoolchildren 13-15 years of age (64.10%), the great majority of them male. The number of cases of tinea was significantly greater in immigrants.

[Imported tuberculosis: an emerging disease in industrialised countries]. / Tuberculosis importada: una enfermedad emergente en países industrializados.

BACKGROUND: The aim of this study was to describe the characteristics of imported tuberculosis (TB) in Barcelona during 1999 and 2000. MATERIAL AND METHOD: Epidemiological surveillance questionnaire. RESULTS: During 1999 and 2000, a 7.9% decrease in TB cases was observed among the native population in Barcelona, whereas cases among immigrants grew up to 47.2%. In 2000, 449 TB cases were detected among the native population (incidence, 29.5/100,000) and 121 among immigrants (incidence, 555.9/100,000). Three outbreaks were identified, involving one Indian community (11 cases), two Dominican families (4 cases) and one city school (2 cases) whose index case was a cooperant. Isolated strains of Mycobacterium tuberculosis at the first, second and third outbreak were multisensitive, multidrug-resistant and isoniazid-resistant, respectively. CONCLUSIONS: The emergence of imported TB cases in Barcelona over 1999 and 2000 suggests that current preventive guidelines must be reviewed.

Mumps vaccine effectiveness in highly immunized populations.

The aim of the study was to investigate effectiveness of mumps MMR component in communities with high MMR coverage. Outbreak-related cases of mumps born between 1995 and 2005 notified to Navarre and Catalonia public health services during the period 2005-2007 were studied. Vaccine effectiveness (VE) and their 95%CI were calculated using the screening method. Of 47 confirmed, 85.1% immunized with at least one dose (1MMR) and 44.9% with two (2MMR). Estimated VE was 85.4% (95%CI: 67.3-93.4) for 1MMR and 88.5% (95%CI: 78.1-93.9) for 2MMR. High 2MMR coverage, improved confirmation techniques and further VE studies with all confirmed cases are needed to prevent further outbreaks.

Evaluación del impacto de los programas de vacunación masiva: la experiencia de la hepatitis A en Cataluña / Evaluation of mass vaccination programmes: the experience of hepatitis A in Catalonia

Fundamento: El programa de vacunación de la hepatitisA + B en preadolescentes se introdujo en 1998 en Cataluña.Durante los siguientes años uno de los objetivos principales hasido cuantificar la reducción en la incidencia de hepatitis Aproducida por el programa de vacunación.Métodos:Se realizó un análisis retrospectivo mediante elestadístico scan espacio-temporal para la tasa de incidencianotificada por hepatitis A en las comarcas de Cataluña desde1992 hasta 2007. Se calcularon los riesgos relativos (RR) y laautocorrelación espacial se estimó mediante el estadístico I deMoran.Resultados:Seis de los 7 clústers espacio-temporalesidentificados por la metodología scan se produjeron en el períodoprevacunal (1992-1998) y sólo uno en el periodo postvacunal(1999-2007). En las 10 primeras cuadrisemanas delperiodo postvacunal (1999-2005) hubo un descenso significativoen de incidencia de hepatitis A en Cataluña respecto alperiodo prevacunal (1992-1998) (p<0,01).Conclusiones. El estadístico I de Moran no mostró ningúnpatrón de dependencia espacial global, y sí fue útil para detectarlos clústers a nivel local. Estos resultados corroboran resultadosprevios que atribuían la mayor parte del descenso en laincidencia de hepatitis A en Cataluña debido al efecto de lavacunación(AU)

Background: The hepatitis A + B vaccination programmeof preadolescents was introduced in 1998 in Catalonia. Duringthe following years, one of the main objectives has been toquantify the reduction in the incidence of hepatitis A caused bythe vaccination programme.Methods:A retrospective analysis applying the space-timescan statistic to reported incidence rates of hepatitis A wascarried out in the counties of Catalonia from 1992 to 2007. Therelative risk (RR) was calculated and the spatial autocorrelationwas estimated using Moran’s I statistic.Results: Six of the 7 space-time clusters identified by thescan statistic occurred in the pre-vaccine era (1992-1998) andonly one in the post-vaccine era (1992-2007). In the first 10four-weekly periods of the post-vaccine era (1999-2005) therewas a significant reduction in the incidence of hepatitis A inCatalonia with respect to the pre-vaccine era (1992-1998)(p<0,01).Conclusions. Moran’s I statistic showed no pattern ofglobal spatial dependence and was useful in detecting localclusters. These results corroborate previous studies thatattributed most of the reduction in the incidence of hepatitis Ain Catalonia to the effect of vaccination(AU)

Tuberculosis importada: una enfermedad emergente en países industrializados / Imported tuberculosis: an emerging disease in industrialised countries

FUNDAMENTO: Describir las características de la tuberculosis importada en Barcelona durante 1999 y 2000. MATERIAL Y MÉTODO: Encuesta epidemiológica. RESULTADOS: En el año 2000 se detectaron 449 casos de tuberculosis en población autóctona (incidencia 29,5/100.000) y 121 en inmigrantes (incidencia 555,9/100.000).Entre 1999 y 2000 la tuberculosis ha disminuido un 7,9 por ciento en la población autóctona de Barcelona, mientras que ha aumentado un 47,2 por ciento en inmigrantes. Hubo tres brotes epidémicos: una comunidad hindú (11 casos), dos familias dominicanas (4 casos) y una escuela (dos casos) cuyo caso índice fue una cooperante. Las cepas de Mycobacterium tuberculosis del primer brote fueron sensibles a todos los fármacos, las del segundo resistentes a los de primera línea y las del tercero resistentes a isoniacida. CONCLUSIONES: La evolución de la tuberculosis en Barcelona en el último bienio confirma la emergencia de casos importados que demandan una revisión de las medidas de control. (AU)