Legionnaires' disease outbreak associated with a cruise liner, August 2003: epidemiological and microbiological findings

SUMMARYEight cases of Legionnaires' disease were identified among the 215 German passengers after a cruise to the Nordic Sea in August 2003. An unmatched case-control study was conducted to identify risk factors and the source of infection. In total, eight passengers fulfilled the case definition, one of these died. Forty-two passengers served as controls. The attack rate was 4%. The mean age was 60 years for cases and 62 years for controls. Prolonged exposure to the spa pool seemed to be a risk factor of infection (OR 4·85,P=0·09).Legionella pneumophilaserogroup 1, monoclonal antibody (mAb) subgroup ‘Knoxville’ was isolated from clinical and environmental samples. DNA sequence-based typing revealed that these isolates were indistinguishable from each other. The investigation showed the importance of an interdisciplinary approach of microbiology and epidemiology as not all sites on the ship that tested positive forL. pneumophilaactually posed a relevant risk for the passengers.

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Legionnaires' disease outbreak in Rome, Italy

Epidemiology and Infection ◽

10.1017/s0950268805004115 ◽

2005 ◽

Vol 133 (5) ◽

pp. 853-859 ◽

Cited By ~ 16

Author(s):

M. C. ROTA ◽

G. PONTRELLI ◽

M. SCATURRO ◽

A. BELLA ◽

A. R. BELLOMO ◽

...

Keyword(s):

Legionella Pneumophila ◽

Cooling Tower ◽

Case Control Study ◽

Hospital Admissions ◽

Case Control ◽

Phenotypic Analysis ◽

Single Strain ◽

Increased Risk ◽

Legionnaires Disease ◽

Control Study

Between August and October 2003, 15 cases of Legionnaires' disease were detected in the 9th district of Rome. To identify possible sources of Legionella exposure, a matched case-control study was conducted and environmental samples were collected. Hospital discharge records were also retrospectively analysed for the period July–November 2003, and results were compared with the same period during the previous 3 years. The case-control study revealed a significantly increased risk of disease among those frequenting a specific department store in the district (OR 9·8, 95% CI 2·1–46·0), and Legionella pneumophila was isolated from the store's cooling tower. Genotypic and phenotypic analysis of human and environmental isolates demonstrated that the cluster was caused by a single strain of L. pneumophila serogroup 1, and that the cooling tower of the store was the source of infection. The increased number of hospital admissions for microbiologically undiagnosed pneumonia during the study period may indicate that some legionellosis cases were not identified.

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Large community-acquired Legionnaires’ disease outbreak caused by Legionella pneumophila serogroup 1, Italy, July to August 2018

Eurosurveillance ◽

10.2807/1560-7917.es.2020.25.20.1900523 ◽

2020 ◽

Vol 25 (20) ◽

Cited By ~ 1

Author(s):

Marino Faccini ◽

Antonio Giampiero Russo ◽

Maira Bonini ◽

Sara Tunesi ◽

Rossella Murtas ◽

...

Keyword(s):

Crossover Study ◽

Legionella Pneumophila ◽

Case Control Study ◽

Dispersion Model ◽

Case Control ◽

Case Crossover ◽

Large Outbreak ◽

Legionnaires Disease ◽

Aerosol Dispersion ◽

Control Study

In July 2018, a large outbreak of Legionnaires’ disease (LD) caused by Legionella pneumophila serogroup 1 (Lp1) occurred in Bresso, Italy. Fifty-two cases were diagnosed, including five deaths. We performed an epidemiological investigation and prepared a map of the places cases visited during the incubation period. All sites identified as potential sources were investigated and sampled. Association between heavy rainfall and LD cases was evaluated in a case-crossover study. We also performed a case–control study and an aerosol dispersion investigation model. Lp1 was isolated from 22 of 598 analysed water samples; four clinical isolates were typed using monoclonal antibodies and sequence-based typing. Four Lp1 human strains were ST23, of which two were Philadelphia and two were France-Allentown subgroup. Lp1 ST23 France-Allentown was isolated only from a public fountain. In the case-crossover study, extreme precipitation 5–6 days before symptom onset was associated with increased LD risk. The aerosol dispersion model showed that the fountain matched the case distribution best. The case–control study demonstrated a significant eightfold increase in risk for cases residing near the public fountain. The three studies and the matching of clinical and environmental Lp1 strains identified the fountain as the source responsible for the epidemic.

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Epidemiological investigation and case–control study: a Legionnaires’ disease outbreak associated with cooling towers in Warstein, Germany, August–September 2013

Eurosurveillance ◽

10.2807/1560-7917.es.2015.20.46.30064 ◽

2015 ◽

Vol 20 (46) ◽

Cited By ~ 15

Author(s):

Anna Maisa ◽

Ansgar Brockmann ◽

Frank Renken ◽

Christian Lück ◽

Stefan Pleischl ◽

...

Keyword(s):

Legionella Pneumophila ◽

Case Control Study ◽

Case Fatality ◽

Case Control ◽

Cooling Towers ◽

Multiple Sources ◽

Source Tracing ◽

Infection Source ◽

Legionnaires Disease ◽

Control Study

Between 1 August and 6 September 2013, an outbreak of Legionnaires’ disease (LD) with 159 suspected cases occurred in Warstein, North Rhine-Westphalia, Germany. The outbreak consisted of 78 laboratory-confirmed cases of LD, including one fatality, with a case fatality rate of 1%. Legionella pneumophila, serogroup 1, subtype Knoxville, sequence type 345, was identified as the epidemic strain. A case–control study was conducted to identify possible sources of infection. In univariable analysis, cases were almost five times more likely to smoke than controls (odds ratio (OR): 4.81; 95% confidence interval (CI): 2.33–9.93; p < 0.0001). Furthermore, cases were twice as likely to live within a 3 km distance from one identified infection source as controls (OR: 2.14; 95% CI: 1.09–4.20; p < 0.027). This is the largest outbreak of LD in Germany to date. Due to a series of uncommon events, this outbreak was most likely caused by multiple sources involving industrial cooling towers. Quick epidemiological assessment, source tracing and shutting down of potential sources as well as rapid laboratory testing and early treatment are necessary to reduce morbidity and mortality. Maintenance of cooling towers must be carried out according to specification to prevent similar LD outbreaks in the future.

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An outbreak of legionnaires’ disease in a municipality in northern Portugal

Eurosurveillance ◽

10.2807/esm.06.07.00228-en ◽

2001 ◽

Vol 6 (7) ◽

pp. 121-124 ◽

Cited By ~ 14

Author(s):

A M Correia ◽

G Gonçalves ◽

J Reis ◽

J M Cruz ◽

J A Castro e Freitas

Keyword(s):

Legionella Pneumophila ◽

Case Control Study ◽

District Hospital ◽

Case Control ◽

Northern Portugal ◽

Legionnaires Disease ◽

Control Study

Eleven cases of legionnaires´ disease, all patients living in the same municipality, were admitted to a district hospital in northern Portugal. Preliminary investigations suggested an association with the events of the annual festivities in that municipality. Legionella pneumophila was not isolated from any of the suspected sources, but evidence from a case control study suggested that an aerosol produced by a decorative fountain in the main square during the night of a rock concert was the likely vehicle of infection. The prevalence of smoking was higher among cases than controls.

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Outbreak of hepatitis A genotype IB in Australia associated with imported frozen pomegranate arils

Epidemiology and Infection ◽

10.1017/s0950268818003515 ◽

2019 ◽

Vol 147 ◽

Cited By ~ 4

Author(s):

N. Franklin ◽

H. Camphor ◽

R. Wright ◽

R. Stafford ◽

K. Glasgow ◽

...

Keyword(s):

Hepatitis A ◽

Case Control Study ◽

Hepatitis A Virus ◽

Case Control ◽

Food Samples ◽

Case Definition ◽

Source Of Infection ◽

Imported Foods ◽

Control Study ◽

Pomegranate Arils

AbstractLocally acquired hepatitis A infection is re-emerging in Australia owing to person-to-person outbreaks among men who have sex with men and imported frozen produce. This paper describes a multi-state foodborne outbreak in the first half of 2018. Enhanced human epidemiological investigation including a case–control study, as well as microbial surveillance and trace-back investigations concluded that the outbreak was caused by consumption of imported frozen pomegranate arils. A total of 30 cases of hepatitis A infection, genotype IB with identical sequences met the outbreak case definition, including 27 primary cases and three secondary cases. Twenty-five (83%) of the cases were hospitalised for their illness and there was one death. Imported frozen pomegranate arils from Egypt were strongly implicated as the source of infection through case interviews (19 of 26 primary cases) as well as from a case–control study (adjusted odds ratio 43.4, 95% confidence interval 4.2–448.8, P = 0.002). Hepatitis A virus (HAV) was subsequently detected by polymerase chain reaction in two food samples of the frozen pomegranate aril product. This outbreak was detected and responded to promptly owing to routine genetic characterisation of HAVs from all hepatitis A infections in Australia as part of a national hepatitis A enhanced surveillance project. This is now the third outbreak of hepatitis A in Australia from imported frozen fruits. A re-assessment of the risk of these types of imported foods is strongly recommended.

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Association of Serum Homocysteine Level and Interstitial Lung Disease in Systemic Sclerosis: A Case-control Study

Current Rheumatology Reviews ◽

10.2174/1573397114666180628162907 ◽

2018 ◽

Vol 15 (1) ◽

pp. 74-78

Author(s):

Mohammadali Nazarinia ◽

Asghar Zare ◽

Mohammad javad Fallahi ◽

Mesbah Shams

Keyword(s):

Systemic Sclerosis ◽

Healthy Subjects ◽

Case Control Study ◽

Homocysteine Level ◽

Case Control ◽

Control Group ◽

Lung Involvement ◽

Serum Homocysteine ◽

The Mean ◽

Control Study

Background:Systemic sclerosis is a disorder of connective tissue with unknown cause, affecting the skin and internal organs, characterized by fibrotic changes.Objective:To determine the correlation between serum homocysteine level and interstitial lung involvement in systemic sclerosis. Materials and Methods: In this case – control study, 59 patients who fulfilled the ACR/EULAR classification criteria for systemic sclerosis and were referred to Hafez Hospital of Shiraz, Iran, were included as the case group. Fifty nine healthy subjects were involved as the control group. Patients were divided into two groups based on interstitial lung involvement and two subtypes, diffuse and limited type. Serum homocysteine, vitamin B12, and folate levels compared between the controls, and cases groups.Results:Of 59 case and control group, 53 (%89.8) were female and the mean age did not differ in both groups (P=0.929). Thirty five (%59.3) patients had interstitial lung involvement and 38(%64.4) had diffuse cutaneous systemic sclerosis. The mean serum homocysteine level was 13.9±6.3 µmol/L in the case and 13.7±9.2 µmol/L in the control group (P=0.86). The mean serum homocysteine level did not differ between the patients with and without interstitial lung involvement (P=0.52). The patients with lung involvement was older than those without lung involvement (P=0.004). Lung disease was more common in diffuse type (P=0.014).Conclusion:In our study, serum homocysteine level did not differ between the patients and healthy subjects. Also, there was no correlation between serum homocysteine level and lung involvement, but lung involvement was more common in older patients and also diffuse subtype.

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COVID-19 and Its Symptoms’ Panoply: A Case-Control Study of 919 Suspected Cases in Locked-Down Ovar, Portugal

Portuguese Journal of Public Health ◽

10.1159/000514925 ◽

2021 ◽

pp. 1-8

Author(s):

Regina Sá ◽

Tiago Pinho-Bandeira ◽

Guilherme Queiroz ◽

Joana Matos ◽

João Duarte Ferreira ◽

...

Keyword(s):

Large Scale ◽

Case Control Study ◽

Statistical Significance ◽

Case Control ◽

Case Definition ◽

Suspected Case ◽

Risk Characteristics ◽

Increased Risk ◽

Wide Range ◽

Control Study

Background: Ovar was the first Portuguese municipality to declare active community transmission of SARS-CoV-2, with total lockdown decreed on March 17, 2020. This context provided conditions for a large-scale testing strategy, allowing a referral system considering other symptoms besides the ones that were part of the case definition (fever, cough, and dyspnea). This study aims to identify other symptoms associated with COVID-19 since it may clarify the pre-test probability of the occurrence of the disease. Methods: This case-control study uses primary care registers between March 29 and May 10, 2020 in Ovar municipality. Pre-test clinical and exposure-risk characteristics, reported by physicians, were collected through a form, and linked with their laboratory result. Results: The study population included a total of 919 patients, of whom 226 (24.6%) were COVID-19 cases and 693 were negative for SARS-CoV-2. Only 27.1% of the patients reporting contact with a confirmed or suspected case tested positive. In the multivariate analysis, statistical significance was obtained for headaches (OR 0.558), odynophagia (OR 0.273), anosmia (OR 2.360), and other symptoms (OR 2.157). The interaction of anosmia and odynophagia appeared as possibly relevant with a borderline statistically significant OR of 3.375. Conclusion: COVID-19 has a wide range of symptoms. Of the myriad described, the present study highlights anosmia itself and calls for additional studies on the interaction between anosmia and odynophagia. Headaches and odynophagia by themselves are not associated with an increased risk for the disease. These findings may help clinicians in deciding when to test, especially when other diseases with similar symptoms are more prevalent, namely in winter.

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Risk factors of dengue fever in an urban area in Vietnam: a case-control study

BMC Public Health ◽

10.1186/s12889-021-10687-y ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Thang Nguyen-Tien ◽

Duy Cuong Do ◽

Xuan Luat Le ◽

Thi Hai Dinh ◽

Mats Lindeborg ◽

...

Keyword(s):

Risk Factors ◽

Dengue Fever ◽

Prevention And Control ◽

Case Control Study ◽

Case Control ◽

Younger Adults ◽

The Mean ◽

Dengue Prevention ◽

And Control ◽

Control Study

Abstract Background Dengue is a mosquito-borne flavivirus present in many metropolitan cities of tropical countries. Methods During and after the dengue season (September 2018 to January 2019), we conducted a case-control study in order to determine the risk factors for dengue fever in Hanoi city, Vietnam. 98 dengue patients and 99 patients with other acute infections, such as Hepatitis B virus infection, were recruited at Department of Infectious Disease of Bach Mai national hospital in Hanoi. Patients were interviewed using a structured questionnaire covering demographic, housing, environmental factors and knowledge, attitude, and practice on dengue prevention and control. Univariate analysis and multivariable logistic regression were used to determine the risk factors of dengue status. Results The mean score of knowledge items and practice items was only 7.9 out of total 19 points and 3.9 out of total 17 points, respectively. While the mean score of attitude items was 4.8 out of total 6 points. Multivariable logistic regression indicated that older patients had lesser risk of getting dengue infection as compared to younger adults aged 16–30, and patients living in peri-urban districts were less likely to suffer of dengue fever than patients living in central urban districts (OR = 0.31; 95% CI 0.13–0.75). This study could not find any association with occupation, water storage habit, knowledge, attitude, or practice on dengue prevention. Conclusions All patients had a relatively low level of knowledge and practice on dengue prevention and control. However, the attitude of the participants was good. We found that age group and living district were the risk factors correlated with the dengue status. Communication programs on raising dengue awareness should be repeated all year round and target particular groups of adolescents, younger adults, landlords and migrants from other provinces to improve their knowledge and encourage them to implement preventive measures against dengue fever.

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Predictors for anaerobic bacteraemia beyond the source of infection: Retrospective, nested, case-control study

Scandinavian Journal of Infectious Diseases ◽

10.1080/00365540802510168 ◽

2009 ◽

Vol 41 (1) ◽

pp. 33-36 ◽

Cited By ~ 4

Author(s):

Jihad Bishara ◽

Morad Wattad ◽

Leonard Leibovici ◽

Zmira Samra ◽

Bruria Lev ◽

...

Keyword(s):

Case Control Study ◽

Case Control ◽

Source Of Infection ◽

Nested Case Control ◽

Control Study

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Risk Factors Associated With Dengue Fever Outbreak in Taiz Governorate, Yemen, 2018: Case-control Study

10.21203/rs.3.rs-624873/v1 ◽

2021 ◽

Author(s):

Abdulkareem Ali Hussein Nassar ◽

Amr Abdulaziz Torbosh ◽

Yassin Abdulmalik Mahyoub ◽

Mohammed Abdullah Al Amad

Keyword(s):

Risk Factors ◽

Dengue Fever ◽

Case Control Study ◽

Significant Risk ◽

Case Fatality ◽

Case Control ◽

Case Definition ◽

P Value ◽

Factors Associated ◽

Control Study

Abstract Background: Dengue Fever (DF) is a significant health problem in Yemen especially in the coastal areas. On November 6, 2018, Taiz governorates surveillance officer notified the Ministry of Public Health and Population on an increase in the number of suspected DF in Al Qahirah and Al Mudhaffar districts, Taiz governorate. On November 7, 2018, Field Epidemiology Training Program sent a team to perform an investigation. The aims were to confirm and describe the outbreak by person, place and time in Taiz governorate, and identify its risk factors.Methodology: Descriptive and case-control study (1:2 ratio) were conducted. WHO case definition was used to identify cases in Al Qahirah or Al Mudhaffar districts during August-November 2018. Control was selected from the same districts who did not suffer from DF. Predesigned questionnaire was used to collect data related to sociodemographic, behavioral and environmental characteristics. Bivariate and multivariate backward stepwise analyses were used. The adjusted odds ratios (aOR) and 95% confidence intervals (95%CI) were calculated. A P value < 0.05 was considered as the cut point for statistically significant. Epi info version 7.2 was used.Results: A total of 50 DF cases were found. Almost 52% were males and 76% were <30 years of age. The overall attack rate was 1/10,000 of the population. Case fatality rate was 4%. In multivariate analysis, not working (aOR = 26.6, 95% CI: 6.8–104.7), not using mosquito repellent (aOR = 13.9, 95% CI:1.4–136.8), wearing short sleeves/pants (aOR = 27.3, 95% CI: 4.8–156.8), poor sanitation (aOR = 5.4, 95% CI: 1.4–20.3), presence of outdoor trees (aOR = 13.2, 95% CI: 2.8–63.0) and houses without window nets (aOR = 15.7, 95% CI: 3.9–63.4) were statistically significant risk factors associated with DF outbreak. Eleven 11 (58%) of blood samples were positive for DF IgM.Conclusions: DF outbreak in Al Qahirah and Al Mudhaffar districts, Taiz governorate was confirmed. This study provides evidence-based information regarding the identified risk factors that contributed to the occurrence of this outbreak. Raising community awareness on the importance of personal protection measures and improving the sanitation services are strongly recommended.

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