Neus Camps

Aetiology and epidemiology of viral gastroenteritis outbreaks in Catalonia (Spain) in 2004–2005

BACKGROUNDnAcute infectious gastroenteritis causes substantial morbidity and economic loss.nnnOBJECTIVEnThe aetiology, epidemiology, and clinical features of acute viral gastroenteritis outbreaks reported during 1 year in Catalonia were investigated.nnnSTUDY DESIGNnThis was a population-based study in which enzyme immunoassay and reverse transcriptase-polymerase chain reaction (RT-PCR) techniques were used to determine the presence of virus in stool specimens from outbreaks clinically and epidemiologically compatible with a viral aetiology and negative for bacteria, parasites and toxins.nnnRESULTSnSixty outbreaks affecting 1791 people were evaluated. Fifty-five outbreaks were positive for norovirus, four were positive for norovirus and other microorganisms (adenovirus, astrovirus, S. Typhimurium and V. parahaemolyticus in one each). Thirty-seven percentage of the outbreaks occurred in collective catering; 18.3% in nursing homes; 10% in hospitals and long-term-care facilities. Foodborne transmission accounted for 50% of outbreaks. Norovirus genotype GGII.4 accounted for 42% of all the outbreaks, being more prevalent in nursing homes, hospital and long-term-care facilities.nnnCONCLUSIONSnThe large number of norovirus outbreaks and resulting health service demand and absenteeism indicate that acute gastroenteritis caused by norovirus is an important health problem in Catalonia. Preventive measures should target education and control of food handlers, and immediate specific control measures should be adopted in institutions.

Epidemiology of pertussis in a country with high vaccination coverage

INTRODUCTIONnPertussis has been a preventable disease in Catalonia since 1965, but the annual number of cases remains high. The aim of this study was to analyze the epidemiology of pertussis in Catalonia and its implications for control purposes.nnnMETHODSnAn epidemiological study was carried out in Catalonia between 2004 and 2008. Pertussis cases reported to the Department of Health were collected and disease reports were filled out with the case information. Incidence rates, rate ratios (RR) and their 95% confidence intervals (CI) were calculated.nnnRESULTSn963 cases were reported: 555 (57.6%) were confirmed and 408 (42.4%) were suspected cases. The reported incidence rate was 2.01 × 10(-5) person years in 2004 and 4.34 in 2008. The biggest increase in cases between 2004 and 2008 was observed in the ≥35 years age group (RR: 6.98; 95%CI: 2.11-36.36). 303 (31.5%) patients were hospitalized, of whom 93.7% were aged <1 year. Clinical differences were observed in paroxysmal cough (83.8% in suspected and 76.4% in confirmed cases, p=0.005), posttussive vomiting (47.1% and 36.1%, respectively, p=0.001), apnoea (13.7% and 21.3%, respectively, p=0.003) and fever (20.1% and 12.4%, respectively, p=0.001).nnnCONCLUSIONnPertussis incidence rates increased during the study period, with the greatest increase occurring in the ≥35 years age group. A booster dose of vaccine in young people could reduce the circulation of B. pertussis in adolescents and adults and indirectly reduce the incidence in children.

Impact of the Legionella urinary antigen test on epidemiological trends in community outbreaks of legionellosis in Catalonia, Spain, 1990–2004

OBJECTIVESnTo describe the characteristics of community outbreaks of legionellosis in Catalonia, Spain from 1990 to 2004, to compare two time periods (1990-1996 and 1997-2004), and to assess the influence of outbreak characteristics on the case fatality rate (CFR).nnnMETHODSnThis is a descriptive analysis of the outbreaks detected by epidemiological surveillance units in Catalonia. Variables potentially related to the CFR were analyzed by logistic regression.nnnRESULTSnOf the 118 outbreaks involving 690 patients (overall CFR 4.5%), the urinary antigen test (UAT) was used for first case diagnosis in 80.5%. The origin of the outbreak was identified as a cooling tower in 35.6%, as a water distribution system in a public building in 14.4%, and a water distribution system at other sites in 7.6%. Statistically significant differences were found in the CFR (12.2% vs. 3.9%; p=0.018) and detection of the first case by UAT (0.0% vs. 87.2%; p<0.001) between the two time periods investigated. Logistic regression showed an increase in the CFR according to outbreak size (adjusted odds ratio (aOR) 1.18; 95% confidence interval (CI) 1.05-1.33) that was significantly lower in the second period (aOR 0.09; 95% CI 0.04-0.20).nnnCONCLUSIONSnSince the UAT was introduced, early diagnosis and treatment has helped to improve the outcomes and CFR of cases involved in outbreaks of legionellosis.

Smoking in tuberculosis patients increases the risk of infection in their contacts

OBJECTIVEnTo determine the risk of latent tuberculous infection (LTBI) among contacts of smokers with tuberculosis (TB).nnnMETHODSnA study was conducted to determine the prevalence of LTBI among contacts of TB cases aged >14 years in Catalonia, Spain. A survey was carried out for each TB case and their contacts. LTBI was diagnosed using the tuberculin skin test (≥5 mm). The risk of LTBI associated with smoking was determined by multi-variate logistic regression analysis, with adjusted odds ratio (aOR) and their 95% confidence intervals (CI).nnnRESULTSnThe smoking prevalence among TB cases was 40.7% (439/1079). The prevalence of LTBI among their contacts was 29.7% (2281/7673). It was higher among contacts of smoking index cases (35.3%) than among those of non-smokers (25.7%). Smoking was independently associated with an increased risk of LTBI among contacts (aOR 1.5, 95%CI 1.3-1.7), and was estimated to be responsible for 12.8% of infections.nnnCONCLUSIONSnIndex case smoking increases the risk of LTBI and should be systematically investigated. A reduction in smoking could lower the risk of infection substantially.

Factors associated with late presentation of HIV infection in Catalonia, Spain

We sought to describe the prevalence, trends and factors associated with late diagnosis of HIV infection between 2001 and 2008 in Catalonia, Spain. Adults over 13 years of age with available CD4 cell counts, who were notified to the Catalonia Voluntary HIV Surveillance System between January 2001 and December 2008, were included in the study. Late presentation for HIV infection was defined as a CD4 cell count <350 cells/μL or with an AIDS-defining condition at presentation. Multivariable logistic regression was used to identify factors independently associated with late diagnosis of HIV. Of the 4651 newly diagnosed HIV-infected individuals with available CD4 counts, 2598 (55.9%) were diagnosed late. The proportion of people with a late diagnosis decreased from 60.4% in 2001 to 50% in 2008, a significant trend (P < 0.001). Older age, male gender, foreign birth, heterosexuality and injecting drug use were independent risk factors for late diagnosis. Strategies to actively promote HIV testing to populations at risk of late diagnosis of HIV or those never attending health systems should be implemented.

Non-preventable mumps outbreaks in schoolchildren in Catalonia

Various doses of the combined MMR vaccine containing the Rubini mumps strain were distributed in Catalonia in 1994 and 1995. We studied outbreaks of mumps reported from 1997 to 2002 to determine the possible involvement of this vaccine in the appearance of non-preventable mumps outbreaks. A total of 17 mumps outbreaks were declared in the period 1997–2000, 14 of which were in schoolchildren. In 11, it was determined that children were correctly vaccinated. Of these, 10 were non-preventable outbreaks. 66% of cases investigated had ages which coincided with vaccination in the period 1994–1996, during which the MMR vaccine containing the Rubini mumps strain was administered. In Catalonia, during the period 1997–2000, at least two-thirds of mumps cases in schoolchildren could be explained by vaccination with the combined MMR vaccine containing the Rubini strain, which has also been associated with mumps outbreaks amongst vaccinated people in other countries.

La respuesta a la prueba de la tuberculina en enfermos tuberculosos

Objetivos Conocer la respuesta a la prueba de la tuberculina (PT) en enfermos tuberculosos. Metodo Revision del resultado de la PT practicada en la valoracion inicial de enfermos tuberculosos diagnosticados en Cataluna (Proyecto Multicentrico de Investigacion en Tuberculosis). PT negativa [PT (−)]: induracion Resultados De los pacientes, 1.566 fueron PT (−) (23%). La PT (−) era mas frecuente en enfermos con factores de riesgo: significativamente con tratamiento inmunosupresor (50%) o infeccion por el VIH (61%), y con menos frecuencia en enfermos sin factores de riesgo (13%) y entre estos, en ninos (1%), pacientes de 15-29 anos (10%) o cuando la tuberculosis era pulmonar (10%), y significativamente mas frecuente en enfermos de 60-74 anos (27%), mayores de 74 (44%) y si la tuberculosis era pulmonar y extrapulmonar (26%) o diseminada (64%). En enfermos sin y con factores de riesgo (incluida o no infeccion por el VIH) con PT (+) la diferencia de las medias de los diametros de las induraciones no fue significativa y en todos los grupos los diametros demostraron una distribucion normal o de Gauss. Conclusiones En la valoracion inicial del enfermo, la PT negativa depende de la existencia de factores de riesgo, la edad, la localizacion y la extension de la tuberculosis. Cuando la PT es positiva, la respuesta es similar, exista o no cualquier factor que pueda deprimir la respuesta inmunitaria.

High incidence of norovirus GII.4 outbreaks in hospitals and nursing homes in Catalonia (Spain), 2010–2011

A descriptive study was performed between 1 January 2010 and 31 December 2011 to estimate the incidence of norovirus outbreaks in hospitals and nursing homes in Catalonia (Spain). Epidemiological surveys were done for each outbreak. Norovirus was confirmed using RT-PCR. The incidence of outbreaks/106 person-years by centre, and the attack rate, were calculated. Statistically significant differences were calculated using odds ratio (ORs) and 95% confidence intervals (CIs). Person-to-person transmission was responsible for 81·5% (22/27) of outbreaks. The incidence in the population was 156·7 outbreaks/106 person-years. The incidence by centre was 1·3% per year and was greater in hospitals (2·6%) than in nursing homes (0·9%) (OR 3·2, 95% CI 1·5-6·9). The global attack rate in residents and staff was 34·7% (816/2348). The mortality rate was 0·25% (2/816). Genogroup GII.4 caused 66·7% of outbreaks. Norovirus GII.4 outbreaks cause significant morbidity affecting both patients and staff.

Mumps: a year of enhanced surveillance in Catalonia, Spain.

Mumps is a vaccine-preventable disease candidate for elimination. Positive predictive value (PPV) of clinical case definition was assessed. During 2007, 410 suspected cases were reported in Catalonia: 348 fulfilled clinical case definition and 159 were laboratory confirmed. Incidence rate was 4.8 per 100,000 for cases that fulfilled the clinical definition, and 2.2 for laboratory confirmed cases. Global PPV was 44.5%; 38.5% in <15 years and 50% in > or =15 years (p=0.04). Most laboratory confirmed cases (72.3%) received at least one MMR dose. With sustained high MMR coverage, laboratory confirmation is necessary to control the disease and assess vaccine failure.

Factors associated to duration of hepatitis a outbreaks: implications for control.

Even though hepatitis A mass vaccination effectiveness is high, outbreaks continue to occur. The aim of this study was to investigate the association between duration and characteristics of hepatitis A outbreaks. Hepatitis A (HA) outbreaks reported between 1991 and 2007 were studied. An outbreak was defined as ≥2 epidemiologically-linked cases with ≥1 case laboratory-confirmed by detection of HA immunoglobulin M (IgM) antibodies. Relationships between explanatory variables and outbreak duration were assessed by logistic regression. During the study period, 268 outbreaks (rate 2.45 per million persons-year) and 1396 cases (rate 1.28 per 105 persons-year) were reported. Factors associated with shorter duration were time to intervention (ORu200a=u200a0.96; 95% CI: 0.94–0.98) and school setting (ORu200a=u200a0.39; 95% CI: 0.16–0.92). In person-to-person transmission outbreaks only time to intervention was associated with shorter outbreak duration (ORu200a=u200a0.96; 95% CI: 0.95–0.98). The only variables associated with shorter outbreak duration were early administration of IG or vaccine and a school setting. Timely reporting HA outbreaks was associated with outbreak duration. Making confirmed HA infections statutory reportable for clinical laboratories could diminish outbreak duration.