Dramatic decline in acute hepatitis B infection and disease incidence rates among adolescents and young people after 12 years of a mass hepatitis B vaccination programme of pre-adolescents in the schools of Catalonia (Spain).

The aim of the study was to describe the impact of hepatitis B vaccination and disease incidence in adolescents and young people 12 years after the launching of a mass hepatitis B vaccination of pre-adolescents in schools. Vaccination coverage was assessed using administrative and serological data. Infection trends were evaluated by means of seroepidemiological surveys. High levels of vaccination coverage and vaccine-induced immunity were achieved. The resulting low proportions of susceptible adolescents and young people have undoubtedly contributed to the substantial reduction in the prevalence of hepatitis B infection in the 15-24 years age group (0.9 per 100 in 2001 versus 9.3 per 100 in 1986) and in the reported incidence of hepatitis B cases (80% reduction). Over the last 3 years, the declining trend seems to have been halted, although 35% of cases reported during this period corresponded to immigrants.

Seroepidemiology of varicella-zoster virus infection in Catalonia (Spain). Rationale for universal vaccination programmes.

With the aim of designing a strategy for vaccination against varicella-zoster virus (VZV), the results of a seroepidemiological survey on VZV infection carried out in a sample of the population of Catalonia are presented. Representative samples from schoolchildren (30 schools) and adults (97 municipal areas) were obtained by random cluster sampling. In the study, 883 children and 1253 adults were included. Age, gender, place of birth, place of residence, educational level and occupation were investigated in the study subjects. An ELISA test was used to measure varicella antibodies. The prevalence of varicella antibodies increased with age, being 85% in the 5-9 years age group, 92% in the 10-14 years age group, 94% in the 15-34 years age group and almost 100% in people over 35. No association was found between sociodemographic variables studied and prevalence levels of antibodies. These results suggest that the best vaccination strategy in Catalonia would be to add a temporary vaccination programme of pre-adolescents at 12 years to routine vaccination at 15 months.

[Changes in seroepidemiology of hepatitis A virus infection in Catalonia in the period 1989-1996. Implications for new vaccination strategy]. / Cambios en la seroepidemiología de la infección por el virus de la hepatitis A en Cataluña en el período 1989-1996. Implicaciones para una nueva estrategia vacunal.

BACKGROUND: The aim of this study was to investigate the prevalence of the risk factors of hepatitis A virus infection (HAV) in a representative sample of a Catalonian population obtained from 1995 to 1996 and the changes in the prevalence of this infection over the period of 1989-1996. SUBJECTS AND METHODS: The prevalence of anti-HAV was determined by an ELISA test in a randomized sample of 2,142 individuals, 884 from 6 to 14 years of age and 1,248 over the age of 15 years. The results were related to sociodemographic variables and multiple logistic regression analysis was performed to establish which variables were related to the risk of infection. RESULTS: The global prevalence of HAV infection was 67.8%. The prevalence of HAV infection increased from 3.5% in the group from 5-14 years of age to 99% in that over the age of 64 years (p < 0.001). A higher prevalence was observed in those born outside of Catalonia (odds ratio [OR] = 3.97; 95% CI, 2.4-6.4) and in those with a lower level of education (OR = 2.60; 95% CI, 1.9-3.5). In the period 1989-1996 the prevalence of the infection has decreased in the population under the age of 45, the differences being statistically significant in the age groups 10-14 (p < 0.0001) and 25-34 (p < 0.0001). CONCLUSIONS: The prevalence of HAV infection has progressively decreased in Catalonia while it proportionally increases the susceptible population under the age of 45 years. These findings may be important in the design of strategies for the prevention of HAV infection with universal vaccination programs against this disease.

Passive smoking and risk of pulmonary tuberculosis in children immediately following infection. A case-control study.

SETTING: Passive smoking-related respiratory disorders in children. OBJECTIVES: To assess the effect of passive smoking on the development of active pulmonary tuberculosis (PTB) in children immediately following infection by Mycobacterium tuberculosis within the family. DESIGN: An unmatched case-control study in which 93 contacts who became cases (active PTB diagnosed) and 95 contacts who did not became cases (tuberculin-positive children without evidence of active disease) were included. All were household contacts of a new case of pulmonary bacillary tuberculosis. Smoking habits were investigated by a questionnaire. Urinary cotinine was analysed. Odds Ratio (OR) was adjusted for age and socio-economic status using multiple logistic regression analysis. RESULTS: Passive smoking was a risk factor for PTB (OR: 5.29; 95% confidence interval (CI): 2.33-12.82; P < 0.00005). The adjusted OR was 5.39 (95% CI: 2.44-11.91; P < 0.00001). The risk increased when contacts were passive smokers both at home and outside the home within the family (OR: 6.35; 95% CI: 3.20, 12.72; P < 0.00001). Contacts 0-4 and 5-9 years old showed a significantly higher risk than those aged > or = 10. There was a dose-response relationship between the risk of developing active PTB immediately following infection and the number of cigarettes smoked daily by the household adults (P < 0.001). Mean (SD) urinary continine detectable concentrations (ng/ml) were different between disease contacts (119.46 [68.61]) and non diseased contacts (91.87 [73.10]). The difference was statistically significant (P < 0.001). CONCLUSIONS: Passive exposure to tobacco smoke in children was associated with an increased risk of developing pulmonary tuberculosis immediately following infection. This is an association of great concern requiring health education programmes and antitobacco medical advice.

[The efficacy of the prevaccination detection of anti-HAV in hepatitis A vaccination programs]. / Eficiencia de la detección prevacunal de anti-VHA en los programas de vacunación antihepatitis A.

BACKGROUND: The convenience of carrying out prevaccination detection studies of hepatitis A virus (HAV) markers depends on the relative costs of the detection and vaccination, as well as the prevalence of susceptible subjects in each population group to be vaccinated. The aim of this study was to analyze the efficacy of the systematic prevaccination detection of anti-HAV antibodies in Catalonia, Spain. METHODS: The following formula was applied: Unit cost of detection + (1-X) x Unit cost of vaccination of anti-HAV negative subjects = group vaccination cost, with X being the threshold of prevalence of marker under which detection no longer remains efficient. This prevalence was compared with the findings of a seroepidemiologic survey carried out in international travellers and food handlers. RESULTS: The unit cost of the detection of anti-HAV was calculated as 2,733 pesetas, and the unit cost of the vaccination as 9,963 pesetas obtaining a prevalence anti-HAV threshold of 27%. This prevalence corresponds to travellers under the age of 30 years and food handlers under the age of 25 years. CONCLUSIONS: The systematic detection of anti-HAV is only recommended in population groups in which prevalences higher than 27% may be expected. The vaccination is more efficient without a previous marker study under this threshold. According to this study, direct vaccination of food handlers under the age of 25 years (born after 1969) is recommended as is that of international travellers under the age of 30 years (born after 1964). In those over the age of these collectives, the prevaccination study is more efficient.

Epidemiologic study of an outbreak of clenbuterol poisoning in Catalonia, Spain.

In an investigation of 113 cases of clenbuterol poisoning in Catalonia, Spain, in 1992, more than 50 percent of those affected were found to have had symptoms of nervousness, tachycardia, muscle tremors, myalgia, and headache. There was no significant difference in the distribution of symptoms according to sex (P = 0.97). The period of incubation varied between 15 minutes and 6 hours and the duration of symptoms between 90 minutes and 6 days. Clenbuterol was detected in 47 urine samples in amounts ranging from 11 to 486 parts per billion. No traces of clenbuterol were found in serum samples. Intoxication occurred in association with the ingestion of veal liver, irrespective of the way in which the liver had been cooked. The association between consuming liver and falling ill was statistically significant (P < 0.0001). In one family, the suspected source of intoxication was meat (veal tongue) and in another canneloni. None of the patients died as a result of the intoxication. The findings reinforce the need to uphold the prohibition of the use of clenbuterol in cattle farming in those countries and communities where it already exists and to contemplate a stricter regulation of its therapeutic use.

[Cost-effectiveness of the methods of smoking cessation]. / Coste-efectividad de los métodos de cesación tabáquica.

BACKGROUND: The cost-effectiveness of the following methods of cessation of smoking were calculated in this study: 1) medical advice, 2) medical advice and nicotine chiclets, and 3) medical advice and nicotine patches. METHODS: The costs and effectiveness of the methods of cessation of smoking compared in terms of cost per year of life gained, deducing the costs and benefits at 5%. RESULTS: The cost per year of life gained was found to be 260,000 to 434,000 pesetas in males and 441,000 to 637,000 in women for medical advice, 287,000 to 479,000 in males and 486,000 to 703,000 in females for advice and nicotine chiclets and 329,000 to 549,000 in males and 557,000 to 805,000 in females for advice and nicotine patches. Maximum efficacy was achieved with the three methods in the age group from 45-59 years in males and from 50-54 years in females. On comparison of cost and effectiveness of the methods of nicotine substitution with those calculated for medical advice the increase in cost-effectiveness was shown to be 395,000 to 658,000 in males and 668,000 to 966,000 in females for advice and chiclets and from 467,000 to 779,000 in males and 791,000 to 1,142,000 in females for advice and patches. The increase in cost-effectiveness for advice and patches versus advice and chiclets was from 539,000 to 899,000 in males and 913,000 to 1,318,000 in females. CONCLUSIONS: The efficiency of achieving the cessation of smoking is very similar for medical advice and medical advice plus nicotine chiclets and is somewhat less for medical advice and nicotine patches. The results of this study place the methods of smoking cessation among the most effective health care procedures.

[Seroepidemiology of hepatitis C virus infection in pregnant women in Catalonia]. / Seroepidemiología de la infección por el virus de la hepatitis C en las mujeres embarazadas de Cataluña.

BACKGROUND: The aim of this study was to investigate the prevalence of hepatitis C virus (HCV) infection in a population of pregnant women in Catalonia and the sociodemographic variables and risk factors associated to this prevalence. METHODS: A representative sample of the pregnant women in Catalonia (n = 4,551) randomly selected by clusters (hospitals with maternity clinics) was studied. Detection of antiHCV antibodies was performed by the third generation ELISA test. Reactive cases were confirmed with RIBA 3 and MATRIX. RESULTS: The prevalence of antiHCV was found to be 1% and was not significantly associated with any of the sociodemographic variables studied (age, social and cultural level, origin and residence). A history of blood transfusion, intravenous drug consumption and hepatitis in the sexual partner were the only risk factors associated with the prevalence of infection found on univariate analysis although these were only present in 47% of the antiHCV positive cases detected. The association between the positivity of antiHCV and the history of hepatitis in the partner was lost on stratification of the cases according to the possible existence of history of drug addiction. CONCLUSIONS: A high proportion of young asymptomatic people (1%) were found to have hepatitis C virus infection with the possible mode of infection not being detected in approximately half of these subjects. In the other half of these cases the infection was found to have been acquired by an intravenous mechanism: blood transfusion or drug use.

Mortality in hypertensive patients in Hospitalet de Llobregat, Barcelona (Spain).

A retrospective cohort study was carried out on 729 hypertensive patients (male and female 40 years and older) in Hospitalet de Llobregat (Barcelona, Spain) to assess possible differences between the mortality of this group of hypertensives and the general population of the same area matched by age and sex. Patient mortality was assessed during a six year period, resulting in a mean follow-up of 2.6 years at the end of the study. The results reflect an increased risk of dying among hypertensives compared with the general population, with standardised mortality ratio by age and sex of 1.88 (95% confidence interval 1.21-2.44). Cardiovascular mortality was significantly higher for males, while noncardiovascular mortality was significantly higher for females. The study also shows that the presence of smoking habit, diabetes or hyperglycaemia, uncontrolled hypertension and age > or = 60 years can increase the risk of dying among hypertensive patients. Although a higher level of BP control is achieved in hypertension hospital clinics than in the primary health care system, the study shows that hypertensives have an excess of mortality than expected considering their own general population by age and sex.

[Efficiency of prevaccination screening of anti-HBc in the anti-hepatitis B vaccination programs]. / Eficiencia de la detección prevacunal de anti-HBc en los programas de vacunación antihepatitis B.

BACKGROUND: The convenience of carrying out pre-vaccination screening of VHB markers depends on the relative costs of screening and vaccination and also on the prevalence of susceptible subjects in each group of the population. The aim of the present work was to analyse the efficiency of pre-vaccination screening of antiHBc in Catalonia in 1991. METHODS: The per-unit cost of screening was calculated at 1366 ptas. The formula applied was: cost per-unit of screening + (1-X) x the cost per-unit of vaccination of anti-HBc (-) = cost of vaccinating the group. "X" being the threshold of prevalence of markers below which screening cases to be efficient. This prevalence is compared with those expected in the groups of the population to be vaccinated. RESULTS: By applying the above-mention ned formula and taking into account costs in time and travel of the people to be vaccinated, a prevalence threshold of 23% is obtained. This prevalence is much higher than that found in adolescents and students of medicine and nursing, similar to that found in health professionals and lower than that of other risk groups. CONCLUSIONS: Systematic screening of anti-HBc is only recommended in groups of the population where a prevalence higher than 20-25% can be expected. Below this threshold vaccination without previous study of markers is more efficient. This enormously simplifies the strategies of universal vaccination of children, adolescents or both.

[Comparative study of human cutaneous sensitivity to 2 and 5 international units of the PPD RT 23 tuberculin with Tween 80]. / Estudio comparativo de la sensibilidad cutánea humana a 2 y 5 unidades internacionales de la tuberculina PPD RT 23 con Tween 80.

BACKGROUND: The aim of this study was to know whether the human reaction to the Mantoux test with 5 UT of PPD RT 23 is similar to that achieved with the same test but with 2 UT of the same substance. METHODS: A simultaneous double Mantoux test was used at doses of 2 UT and another of 5 UT of the same trade mark of tuberculin PPD RT 23 with Tween 80 in 2,575 individuals. The subjects were distributed into two different groups of different ages, taking into consideration the possible presence of BCG vaccination. RESULTS: The doses of 5 UT produced a greater number of tuberculin positive individuals and a greater diameter of induration of reaction than that of the doses of 2 UT in both groups and with significant statistical differences. One hundred ninety-six (7%) subjects were tuberculin positive with 5 UT and negative with 2 UT. CONCLUSIONS: The reactions produced by the Mantoux test with 5 and 5 UT PPD RT were different since the two doses are not bioequivalent.

Prevalence of hepatitis B markers in the population of Catalonia (Spain). Rationale for universal vaccination of adolescents.

The prevalence of hepatitis B markers was determined in a representative sample of the general population of Catalonia (Spain). HBsAg was found in 0.5% of children (less than 15 years of age) and in 1.7% of adults (more than 15 years of age), and anti HBs in 1.6% and 18%, respectively. Age-specific prevalence for both markers showed a low risk for hepatitis B before puberty, and a progressive rise since adolescence, suggesting that perinatal transmission and horizontal transmission in children are relatively uncommon in Spain. Prevalence of hepatitis B markers was significantly higher among subjects with low education level, residing in an urban area and born outside Catalonia, but in the stratified analysis, a statistical significant difference was only maintained in the prevalence of HBV markers between those who live in urban and rural areas, and between those who were born outside Catalonia and in Catalonia. These data may be used as a basis for a strategy of hepatitis B prevention in Spain which include universal vaccination of adolescents, passive-active immunization of newborns to HBsAg positive mothers and vaccination of susceptible adults subjects from high-risk groups.