Risk of tuberculosis among pulmonary tuberculosis contacts: the importance of time of exposure to index cases.

INTRODUCTION: The intensity of exposure to index cases of tuberculosis [TB] may increase the risk of TB in their contacts. The aim was to determine TB risk factors among contacts of TB index cases. METHODS: A cohort study was carried out in the contacts of pulmonary TB cases registered by the epidemiological surveillance network from 01/01/2019 to 06/30/2021. The factors associated with the risk of TB in contacts were determined using the adjusted odds ratio [aOR] and its 95% confidence interval [CI]. RESULTS: From 847 TB cases, 7087 contacts were identified. The prevalence of TB was 2.0% [145/7087] and was higher in < 5 years compared to those ≥ 65 years [4.4% versus 1.2%; p < 0.001], in those exposed ≥ 6 h daily [4%], and < 6 h daily [1.6%] with respect to weekly exposure of < 6 h [0.7%; p < 0.001]. Those contacts exposed ≥ 6 h daily [aOR= 6.9; 95%CI:2.1-22.1], < 5 years [aOR= 8.3; 95%CI:1.8-37.8] and immigrants [aOR= 1.7; 95%CI:1.1-2.7] had a higher risk of TB. CONCLUSIONS: The risk of TB increases with the time of exposure to the index case and this risk is also higher in < 5 years and immigrants. Contact tracing has a high yield for detecting new cases of TB.

Impact of the COVID-19 pandemic on contact tracing of patients with pulmonary tuberculosis.

BACKGROUND: The COVID-19 pandemic could have negative effects on tuberculosis (TB) control. The objective was to assess the impact of the pandemic in contact tracing, TB and latent tuberculosis infection (LTBI) in contacts of patients with pulmonary TB in Catalonia (Spain). METHODS: Contact tracing was carried out in cases of pulmonary TB detected during 14 months in the pre-pandemic period (1 January 2019 to 28 February 2020) and 14 months in the pandemic period (1 March 2020 to 30 April 2021). Contacts received the tuberculin skin test and/or interferon gamma release assay and it was determined whether they had TB or LTBI. Variables associated with TB or LTBI in contacts (study period and sociodemographic variables) were analyzed using adjusted odds ratio (aOR) and the 95% confidence intervals (95% CI). RESULTS: The pre-pandemic and pandemic periods showed, respectively: 503 and 255 pulmonary TB reported cases (reduction of 50.7%); and 4676 and 1687 contacts studied (reduction of 36.1%). In these periods, the proportion of TB cases among the contacts was 1.9% (84/4307) and 2.2% (30/1381) (P = 0.608); and the proportion of LTBI was 25.3% (1090/4307) and 29.2% (403/1381) (P < 0.001). The pandemic period was associated to higher LTBI proportion (aOR = 1.3; 95% CI 1.1-1.5), taking into account the effect on LTBI of the other variables studied as sex, age, household contact and migrant status. CONCLUSIONS: COVID-19 is affecting TB control due to less exhaustive TB and LTBI case detection. An increase in LTBI was observed during the pandemic period. Efforts should be made to improve detection of TB and LTBI among contacts of TB cases.

Factors influencing the spread of pertussis in households: a prospective study, Catalonia and Navarre, Spain, 2012 to 2013.

We aimed to investigate transmission rates of pertussis in household contacts of cases and factors associated with transmission. A prospective epidemiological study was conducted in 2012 and 2013 to determine the incidence of pertussis among household contacts of reported cases in Catalonia and Navarre, Spain. An epidemiological survey was completed for each case and contact, who were followed for 28 days to determine the source of infection (primary case) and detect the occurrence of secondary cases. Odds ratios (ORs) were used to estimate the effectiveness of vaccination and chemoprophylaxis in preventing new cases, using the formula (1 - OR) × 100. For the 688 primary cases, a total of 2,852 contacts were recorded. The household transmission rate was 16.1% (459/2,852) and rose according to the age (> 18 years) and lack of immunisation of the primary cases, and also the age (0-18 years), family relationship (siblings and children), lack of vaccination and chemoprophylaxis of contacts. Pertussis vaccine effectiveness in preventing new cases was 65.0% (95% confidence interval (CI): 11.6 to 86.2) for full vaccination (≥ 4 doses) and 59.7% (95% CI: -6.8 to 84.8) for incomplete vaccination (< 4 doses). The effectiveness of chemoprophylaxis was 62.1% (95% CI: 40.3 to 75.9). To reduce household transmission, contacts should be investigated to detect further cases and to administer chemoprophylaxis. The current vaccination status of cases and contacts can reduce household transmission.

Toscana virus infection in Catalonia (Spain).

Toscana virus (TOSV), an arthropod-borne phlebovirus, is an important agent of acute meningitis and meningoencephalitis in the Mediterranean area. The epidemiology of the infection in humans in Catalonia is at present unknown. In this study, we found a seroprevalence of infection of 6%, and 2 clinical cases were detected by serology and/or PCR.

Seroepidemiology of hepatitis B virus infection in pregnant women in Catalonia (Spain).

BACKGROUND: In recent years there has been a substantial reduction in hepatitis B incidence as a result of routine vaccination of preadolescents and the selective vaccination of high risk groups and newborns of HBsAg+ mothers. OBJECTIVES: To determine the prevalence of hepatitis B virus infection markers and of serologic markers of hepatitis B vaccination in a representative sample of pregnant women in Catalonia. STUDY DESIGN: A representative sample was obtained by random cluster sampling (hospitals with maternity units) stratified by provinces. Anti-HBc, anti-HBs and HBsAg were determined using an ELISA test (Behring, Marburg, Germany). The crude and adjusted odds ratios for the sociodemographic variables analyzed were also calculated. RESULTS: The global prevalence of carriers of HBsAg+ was 0.1% (95% CI 0.0-0.3), that of hepatitis B infection (anti-HBc+) was 5% (95% CI 3.9-6.1) and that of serologic markers of vaccination (anti-HBs+ and anti-HBc-) was 16.4% (95% CI 14.5-18.2) The prevalence of infection increased with age from 3.0% (15-19 years age group) to 14.8% (40-44 years age group). The prevalence of anti-HBc+ was higher in women born in Asia (27.6%) and Africa (18.8%) than in those born in Spain (3.7%), Europe (3.3%) and America (4.6%), with the differences being statistically significant. CONCLUSIONS: The results of this study confirm the change in the pattern of endemicity of hepatitis B infection in pregnant women in Catalonia after the introduction of vaccination programmes. They also confirm the increasingly important role played by immigration in the epidemiology of hepatitis B.

Prevalence of hepatitis E virus infection in children in the northeast of Spain.

The prevalence of immunoglobulin G (IgG) anti-hepatitis E virus (anti-HEV) antibodies was studied with a representative sample of 1,249 healthy children aged between 6 and 15 years. IgG anti-HEV antibodies were detected in 57 (4.6%) of the 1,249 samples analyzed, suggesting that some children are exposed to HEV in early childhood.

Seroprevalence of varicella zoster virus infection in child and adult population of Catalonia (Spain).

The aim of this study was to determine the prevalence of varicella IgG antibodies in the population of Catalonia, and the variables associated. The study was carried out in 2002 in a representative sample of juvenile (5-14 years) and adult population (> or =15 years) of Catalonia (Spain). The global prevalence determined by ELISA test was 95.5% (95% CI 94.7-96.3). The prevalence increased with age, from 82% (95% CI 77.0-87.0) in the 5-9 years age up to 99.4% (95% CI 98.2-100) in >64 years of age. No statistically significant differences in the seroprevalence according to the sociodemographic variables were observed. The current strategy of vaccinating preadolescents at 12 years of age who have not suffered the disease will require more than 30 years to cover the current gap immunity in adolescents and young adults. Vaccination with two doses of vaccine for all adolescents and adults < or = 50 years who report not having suffered the disease during childhood should be considered.

Declining hepatitis A seroprevalence in adults in Catalonia (Spain): a population-based study.

BACKGROUND: One of the main uses of seroprevalence studies it to evaluate vaccination programmes. In 1998, a programme of universal vaccination of preadolescents in schools with the hepatitis A vaccine was begun in Catalonia. The objective of this study was to investigate the prevalence and risk factors of hepatitis A virus infection (HAV) in a sample of the adult population of Catalonia in 2002 and to evaluate the changes with respect to a survey carried out in 1996. METHODS: The prevalence of HAV antibodies was determined by a third generation competitive immunometric assay in a representative sample of 1292 people aged >15 years. The association between the prevalence and different sociodemographic variables was determined by multiple logistic regression analysis. RESULTS: The standardized global prevalence of HAV antibodies in 2002 was 68.2%, increased with age (p < 0.0001) and was associated with being born outside Catalonia (OR: 1.75; 95% CI 1.11-2.76) and lower social class (OR: 1.14; 95% CI 1.05-1.25). Compared with the last survey carried out in 1996 the standardized global prevalence was lower (68.2% vs 77.8%; p < 0.0001) as was the prevalence in people under 45 years. CONCLUSION: The prevalence of the hepatitis A virus is decreasing in the adult population of Catalonia, especially in the younger age groups. The programme of vaccination of adolescents begun in 1998 to control the disease can provide indirect protection to the unvaccinated population.

Rubella immune status of indigenous and immigrant pregnant women in Catalonia, Spain.

BACKGROUND: The objective of the study was to determine the prevalence of rubella antibodies in representative samples of pregnant women in Catalonia. METHODS: A representative sample of pregnant women in Catalonia was obtained by random sampling by clusters (hospitals with maternity units) stratified by provinces. Blood was obtained from the umbilical cord at childbirth in 1538 women (of whom 308 were immigrants) and was tested for rubella antibodies by ELISA (Enzime-linked immunosorbent assay). RESULTS: The global prevalence of antibodies was 93.4% [95% confidence interval (CI): 93.3-93.5] and was significantly higher in indigenous women (94.9;95%CI:93.3-95.9) compared with immigrants [89.0; 95%CI: 85.5-92.5 (P<0. 0001)] with crude Odds ratio (OR) of 2.15 (95%CI: 1.40-3.32).The prevalence was higher in women living in rural habitats (97%) and those in higher social classes (96.3%); OR 2.54 (95%CI: 1.22-5.30) and 2.17 (95%CI: 1.24-3.81), respectively. CONCLUSION: Fertile female immigrants from countries with no vaccination or where vaccination coverage is low should be actively approached for vaccination to reduce the risk of infection and congenital rubella.

Community-based seroepidemiological survey of hepatitis E virus infection in Catalonia, Spain.

The objective of the study was to investigate the prevalence of immunoglobulin G (IgG) antibodies to hepatitis E virus (HEV) infection in a population sample from Catalonia and to analyze the demographic and clinical variables associated with the presence of these antibodies. A total of 1,280 subjects between 15 and 74 years of age were selected randomly from urban and rural areas. Data for sociodemographic and clinical variables were collected by using a questionnaire. IgG antibodies to HEV were determined by an immunoenzymatic method. The odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated for studied variables. Multiple logistic regression analysis was used to determine which variables were independently associated with the prevalence of HEV infection. Anti-HEV antibodies were detected in 96 (7.3%) of the 1,280 samples analyzed. The prevalence of antibodies was greater among males (7.8%) than among women (7%) and increased with age for both sexes, from 3% among subjects 15 to 24 years of age to 12% among subjects >/=65 years of age. Bivariate analysis of the sociodemographic and clinical variables showed an association between the prevalence of hepatitis E virus infection and minor surgery (OR, 1.96; 95% CI, 1.24 to 3.11), abdominal surgery (OR, 1.74; 95% CI, 1.12 to 2.73), and, for women, being uniparous or multiparous (OR, 2.84; 95% CI, 1.19 to 6.79). The multivariate analysis showed an association with minor surgery only (OR, 1.68; 95% CI, 1.03 to 2.70). In conclusion, anti-HEV antibodies were detected in 7.3% of the Catalan population. The seroprevalence of anti-HEV antibodies increased with age and was associated with previous minor surgery.

Rubella elimination programme strengthened through measles elimination programme in Catalonia.

The drastic fall in rubella cases recorded in Catalonia from 1988 on, when the second dose of Measles-Mumps-Rubella (MMR) vaccine was implemented, and especially from 1998, when the measles elimination programme began, led to the introduction, in May 2002, of the rubella and congenital rubella syndrome elimination by 2005 programme. From May 2002 to May 2004, 13 suspected rubella cases were reported to the Statutory Disease Reporting System; of these, one postnatal case and one congenital rubella case were confirmed (15.4%), both being imported cases. Through the screening of viruses established in the measles elimination programme, 28 possible cases were analyzed and six (21.4%) confirmed imported postnatal rubella cases were detected. The small number and imported nature of the cases of rubella and the detection of the majority of the confirmed cases through the measles elimination programme, strongly suggests that both programmes should continue.

Prevalence of hepatitis A antibodies in schoolchildren in Catalonia (Spain) after the introduction of universal hepatitis A immunization.

The objective of this study was to investigate the prevalence of hepatitis A antibodies (anti-HAV) in schoolchildren in Catalonia and to compare it with the rates found in previous studies. Sera from a representative sample of 1,342 children aged between 6 and 15 years, recruited in 2001, were tested for anti-HAV. The results were related to sociodemographic variables and vaccination history. The overall prevalence of anti-HAV was 51.4%. The prevalence was 5.5% in non-vaccinated children, similar to that found in a 1996 study, and 96.6% in vaccinated children. The prevalence of anti-HAV in non-vaccinated children increased significantly with age, reaching 11.6% in the 13-15 years age group. The prevalence of anti-HAV was higher in children born outside Catalonia than in those born in Catalonia (16.1% vs. 5.0%, P = 0.02). The expected continuation in the decline in the prevalence of anti-HAV in non-vaccinated schoolchildren, observed in Catalonia since 1986, was not found in 2001. The rate of anti-HAV in 2001 was slightly higher than in 1996, although the difference was not statistically significant (5.5 and 3.5%, respectively). This could be explained by the increased number of recent immigrant children born outside Catalonia, mainly in countries where hepatitis A is highly endemic.

Enfermedades prevenibles mediante vacunaciones sistemáticas. Evaluación de los objetivos del Plan de Salud de Cataluña para el año 2000 / Vaccine preventable diseases. Evaluation of the objectives of the Health Plan for Catalonia for the year 2000

Fundamento y objetivos: Evaluar la consecución de los objetivos de salud fijados en el Plan de Salud de Cataluña para el año 2000 en materia de enfermedades prevenibles mediante vacunaciones de aplicación sistemática (mantener la eliminación de la difteria y de la poliomielitis, reducir significativamente el número de casos de tétanos, tos ferina, parotiditis y rubéola, y eliminar el sarampión autóctono y la rubéola congénita). También se han evaluado los objetivos operacionales fijados en el plan (alcanzar coberturas vacunales superiores al 97% en la población infantil y del 60% en la población adulta). Población y método: La cobertura vacunal se ha estimado a partir de la prevalencia de inmunidad antitetánica obtenida en las encuestas seroepidemiológicas efectuadas en los años 1996 y 2001 y de inmunidad antisarampión en las encuestas seroepidemiológicas de los años 1983, 1986 y 1996. Los objetivos de salud (reducción en la incidencia de las enfermedades vacunables) se han evaluado analizando la morbilidad declarada al Sistema de Enfermedades de Declaración Obligatoria. Resultados: Las coberturas vacunales para la inmunización básica con la vacuna triple bacteriana (difteria, tétanos y tos ferina; DTP) más polio oral y para la dosis de Td a los 14-16 años, estimadas a partir de la prevalencia de inmunidad antitetánica (99,2% y 98,6%, respectivamente) superan los objetivos fijados en el Plan de Salud (97%). Lo mismo cabe decir de la cobertura de vacuna triple vírica a los 11 años de edad, estimada a partir de la prevalencia de inmunidad antisarampión. El año 2000 no se ha declarado ningún caso de difteria, poliomielitis y rubéola congénita. Sólo se ha declarado un caso de sarampión, posiblemente importado, y dos de rubéola posnatal, 115 de parotiditis, 5 de tétanos y 193 de tos ferina. Discusión: Los objetivos fijados en el Plan de Salud de Cataluña para el año 2000, en materia de enfermedades prevenibles mediante vacunaciones sistemáticas, se han alcanzado en su totalidad (AU)

Background and objectives: To assess whether the health objectives set out in the Catalonian Health Plan were achieved as regards preventable diseases via systematically applied vaccinations (sustain the elimination of diphtheria and poliomyelitis, significantly reduce the number of cases of tetanus, pertussis, parotiditis and rubella, and to eliminate autochthonous measles and congenital rubella). The operational goals contained in the Plan have also been evaluated (to reach vaccination coverage levels of over 97% in the infant population and 60% in the adult population). Subjects and method: The vaccination coverage has been estimated based on the prevalence of antitetanic immunity obtained from sero-epidemiological surveys conducted in 1996 and 2001 and anti-measles immunity in sero-epidemiological surveys in 1983, 1986 and 1996. Health objectives (reduction of the incidence of vaccine-preventable diseases) have been evaluated by studying the morbidity reported to the system of compulsorily notifiable diseases. Results: Vaccination coverage for basic immunization with DTP + oral polio and the dose of Td at ages 14-16, estimated using the prevalence of antitetanic immunity (99.2% and 98.6% respectively) exceed the objectives set out in the health Plan (97%). The same can be said of the triple viral vaccination coverage at age 11, estimated using the prevalence of anti-measles immunity. In 2000 no case of diphtheria, poliomyelitis and congenital rubella was reported. Only one case of measles was declared which was possibly imported, and two of postnatal rubella, 115 of parotiditis, 5 of tetanus and 193 of pertussis. Discussion: The objectives set out in the Catalonia Health Plan for 2000 in the field of diseases which are preventable via the application of systematic vaccinations have been fully achieved (AU)

Efectividad del programa masivo de vacunación antihepatitis B de los preadolescentes en las escuelas de Cataluña / Effectiveness of the mass antihepatitis B program in preadolescents in Catalonia

Fundamento y objetivo: Evaluar la consecución de los objetivos de salud para el año 2000 (reducción hasta el 1% de la prevalencia de anti-HBc en el grupo de edad de 15 a 24 años) y operacionales (alcanzar una cobertura vacunal del 90%) del programa de vacunación antihepatitis B de los preadolescentes en las escuelas de Cataluña. Población y método: Las coberturas vacunales se han evaluado midiendo la prevalencia de inmunidad inducida por la vacuna (anti-HBs+ y anti-HBc¿) en adolescentes de 14 años en las encuestas seroepidemiológicas efectuadas los años 1996 y 2001. El objetivo de salud se ha evaluado midiendo la prevalencia de anti-HBc en la submuestra de población de 15 a 24 años de las encuestas seroepidemiológicas de la población adulta llevadas a cabo los años 1996 y 2001. Los resultados de estas encuestas se han comparado con los de una encuesta efectuada el año 2001. Resultados: La prevalencia de inmunidad inducida por la vacuna (anti-HBs+ y anti-HBc¿), en los escolares de 14 años, ha sido del 94% en 1996 y la proporción de susceptibles a la infección ha pasado del 97,5% el año 1986 al 5,5% en la actualidad. La prevalencia del antecedente de infección por el virus de la hepatitis B (anti-HBc+) en el grupo de edad de 15 a 24 años ha pasado del 9,3% en 1986 al 0,9% en 1996. Conclusiones: Los objetivos de salud para el año 2000 en relación con el programa de vacunación antihepatitis B de los preadolescentes de 12 años en las escuelas se han alcanzado en su totalidad (AU)

Background and objectives: To evaluate whether the health objectives for the year 2000 were achieved (reduction to 1% prevalence of antiHBc in the 15-24 age group) together with the operational objectives (to reach a vaccination coverage of 90%) of the antihepatitis B vaccination of preadolescents in Catalan schools. Subjects and method: The vaccination coverage has been evaluated by measuring the prevalence of vaccine-induced immunity (antiHBs + and antiHBc) in 14 years old adolescents in the sero-epidemiological surveys conducted in 1996 and 2001. The health objective was evaluated by measuring the prevalence of antiHBc in the sub sample of the population between 15 and 24 in the sero-epidemiological surveys of the adult population conducted in 1996 and 2001. The results of these surveys have been compared with those of a survey carried out in 1986. Results: The prevalence of vaccine-induced immunity (antiHBs+ and antiHBc¿), in 14-year old schoolchildren was 94% in 1996 and the proportion of those susceptible to infection dropped from 97.5% in 1986 to the current 5.5%. The prevalence of previous infection by the hepatitis B virus (antiHBc+) in the 15-24 age group fell from 9.3% in 1986 to 0.9% in 2001. Conclusions: The health objectives for 2000 relating to the antihepatitis B vaccination programme in 12 year-old preadolescents in schools have been fully achieved (AU)