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

2015 ◽  
Vol 20 (46) ◽  
Author(s):  
Anna Maisa ◽  
Ansgar Brockmann ◽  
Frank Renken ◽  
Christian Lück ◽  
Stefan Pleischl ◽  
...  

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.

1991 ◽  
Vol 107 (1) ◽  
pp. 133-141 ◽  
Author(s):  
D. A. Hunt ◽  
K. A. V. Cartwright ◽  
M. C. Smith ◽  
J. Middleton ◽  
C. L. R. Bartlett ◽  
...  

SUMMARYFourteen people living in or near the city of Gloucester fell ill with Legionnaires' disease caused by Legionella pneumophila serogroup (SG) 1 between 27 August and 27 October 1986. Another patient had fallen ill on 30 May. Nine of the 15 were diagnosed retrospectively during a case finding exercise. There were three deaths. Three cases of Pontiac fever were also diagnosed.The source was probably one or more wet cooling towers. Nineteen premises in the city with such towers were identified, and three just outside Gloucester. Samples from 11 of the 22 premises grew Legionella spp.; from nine of these L. pneumophila SG 1 (Pontiac) was isolated. The efficacy of regular addition of biocide in addition to hypochlorite added at the time of disinfection in inhibiting the growth of Legionella spp. was demonstrated.A survey of patients' movements during their likely incubation period showed that there was no single building that all patients had visited, but there were two areas of the city which nearly all had visited or passed through by car. A case-control study demonstrated an association with one of these areas.Cooling towers near both areas may have been sources but the evidence is insufficient to incriminate any single one. The unexpected finding of L. pneumophila SG 1 (Pontiac) in nine towers supports the hypothesis that there may have been multiple sources. Cooling towers may have been contaminated by mains water or by drift from other towers.


2006 ◽  
Vol 135 (5) ◽  
pp. 802-810 ◽  
Author(s):  
K. BEYRER ◽  
S. LAI ◽  
J. DREESMAN ◽  
J. V. LEE ◽  
C. JOSEPH ◽  
...  

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.


2005 ◽  
Vol 133 (5) ◽  
pp. 853-859 ◽  
Author(s):  
M. C. ROTA ◽  
G. PONTRELLI ◽  
M. SCATURRO ◽  
A. BELLA ◽  
A. R. BELLOMO ◽  
...  

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.


2020 ◽  
Vol 25 (20) ◽  
Author(s):  
Marino Faccini ◽  
Antonio Giampiero Russo ◽  
Maira Bonini ◽  
Sara Tunesi ◽  
Rossella Murtas ◽  
...  

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.


2001 ◽  
Vol 6 (7) ◽  
pp. 121-124 ◽  
Author(s):  
A M Correia ◽  
G Gonçalves ◽  
J Reis ◽  
J M Cruz ◽  
J A Castro e Freitas

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.


2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S332-S332
Author(s):  
Anna Hardesty ◽  
Aakriti Pandita ◽  
Yiyun Shi ◽  
Kendra Vieira ◽  
Ralph Rogers ◽  
...  

Abstract Background Organ transplant recipients (OTR) are considered high-risk for morbidity and mortality from COVID-19. Case-fatality rates (CFR) vary significantly in different case series, and some patients were still hospitalized at the time of analyses. To our knowledge, no case-control study of COVID-19 in OTR has been published to-date. Methods We captured kidney transplant recipients (KTR) diagnosed with COVID-19 between 3/1 and 5/18/2020. After exclusion of KTR on hemodialysis and off immunosuppression (IS), we compared the clinical course of COVID-19 between hospitalized KTR and non-transplant patients, matched by sex and age (controls). All patients were discharged from the hospital or died. Results 16 KTR had COVID-19. All 3 KTR off IS, who were excluded from further analyses, survived. Median age was 54 (range: 34–65) years; 5/13 KTR (38.4%) were men. Median time from transplant was 41 (range: 1–203) months. Two KTR, both transplanted &gt;10 years ago, were managed as outpatients. IS was reduced in 12/13 (92.3%), most often by discontinuation of the antimetabolite. IL6 levels were &gt;1,000 (normal: &lt; 5) pg/mL in 3 KTR. Tacrolimus or sirolimus levels were &gt;10 ng/mL in 6/9 KTR (67%) (Table 1). Eleven KTR were hospitalized (84.6%) and matched with 44 controls. One KTR, the only one treated with hydroxychloroquine, died (CFR 5.8%; 7.6% in KTR on IS; 9% in hospitalized KTR on IS). Four controls died (CFR: 9%; state CFR: 5.2%; inpatient CFR: 16.6%). There were no significant differences in length of stay or worst oxygenation status between hospitalized KTR and controls. Four KTR (30.7%), received remdesivir, 4 convalescent plasma, 3 (23%) tocilizumab. KTR received more often broad-spectrum antibiotics, convalescent plasma or tocilizumab, compared to controls (Table 2). Table 1 Table 2 Conclusion Unlike early reports from the pandemic epicenters, the clinical course and outcomes of KTR with COVID-19 in our small case series were comparable to those of non-transplant patients. Calcineurin or mTOR inhibitor levels were high, likely due to diarrhea and COVID-19-related hepatic dysfunction. Extremely high IL6 levels were common. The role of IS and potential benefits from investigational treatments remain to be elucidated. A larger multi-institutional study is underway. Disclosures All Authors: No reported disclosures


2021 ◽  
Author(s):  
Abdulkareem Ali Hussein Nassar ◽  
Amr Abdulaziz Torbosh ◽  
Yassin Abdulmalik Mahyoub ◽  
Mohammed Abdullah Al Amad

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.


2019 ◽  
Author(s):  
Mengistie Kassahun Tariku ◽  
Sewnet Wongiel Misikir

Abstract Objective: To confirm the existence of Outbreak, describe cases in person, place and time, and identify determinants of the outbreak. Unmatched case control study in the ratio of 1:4 (38 cases and 152 controls) was conducted in Artuma fursi woreda from July 13- August 1 /2018. Data were collected with standard questionnaires. Collected data were entered into Epi Info version 7 and exported to Statistical package for social science (SPSS) version 23 for analysis. Results: A total of 38 cases and 1 death with attack rate and case fatality rate 11.8/100,000 and 2.6% respectively. All study participants had not vaccination history. Females and age group 5-14 were more affected. Being 5-14 years old versus (vs) 15 years [adjusted odd ratio (AOR) =3.53; 95% CI; 1.52-8.45)], contact with cases vs no contact with cases [AOR=2.78; 95% CI; 1.23-8.67] and travel history 7-18 days prior onset of illness vs no travel history [AOR= 2.53; 95% CI; 1.31-7.24] were significantly associated with contracting measles. Routine and supplement immunization should be strengthened to reduce future occurrence of outbreak. Keywords: Measles, outbreak, Artuma fursi woreda


2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Godfrey Nsereko ◽  
Daniel Kadobera ◽  
Denis Okethwangu ◽  
Joyce Nguna ◽  
Damian Rutazaana ◽  
...  

Background. Malaria is a leading cause of morbidity and mortality in Uganda. In April 2018, malaria cases surged in Nwoya District, Northern Uganda, exceeding expected limits and thereby requiring epidemic response. We investigated this outbreak to estimate its magnitude, identify exposure factors for transmission, and recommend evidence-based control measures. Methods. We defined a malaria case as onset of fever in a resident of Anaka subcounty, Koch Goma subcounty, and Nwoya Town Council, Nwoya District, with a positive rapid diagnostic test or microscopy for malaria from 1 February to 25 May 2018. We reviewed medical records in all health facilities of affected subcounties to find cases. In a case-control study, we compared exposure factors between case-persons and asymptomatic controls matched by age and village. We also conducted entomological assessments on vector density and behavior. Results. We identified 3,879 case-persons (attack rate [AR] = 6.5%) and two deaths (case-fatality rate = 5.2/10,000). Females (AR = 8.1%) were more affected than males (AR = 4.7%) (p<0.0001). Of all age groups, 5–18 years (AR = 8.4%) were most affected. Heavy rain started in early March 2018, and a propagated outbreak followed in the first week of April 2018. In the case-control study, 55% (59/107) of case-persons and 18% (19/107) of controls had stagnant water around households for several days following rainfall (ORM-H = 5.6, 95% CI = 3.0–11); 25% (27/107) of case-persons and 51% (55/107) of controls wore full extremity covering clothes during evening hours (ORM-H = 0.30, 95% CI = 0.20–0.60); 71% (76/107) of case-persons and 85% (91/107) of controls slept under a long-lasting insecticide-treated net (LLIN) 14 days before symptom onset (ORM-H = 0.43, 95% CI = 0.22–0.85); 37% (40/107) of case-persons and 52% (56/107) of controls had access to at least one LLIN per 2 household members (ORM-H = 0.54, 95% CI = 0.30–0.97). Entomological assessment indicated active breeding sites in the entire study area; Anopheles gambiae sensu lato species were the predominant vector. Conclusion. Increased vector-breeding sites after heavy rainfall and inadequate malaria preventive measures were found to have contributed to this outbreak. We recommended increasing coverage for LLINs and larviciding breeding sites in the area.


1989 ◽  
Vol 103 (2) ◽  
pp. 285-292 ◽  
Author(s):  
M. O'Mahony ◽  
A. Lakhani ◽  
A. Stephens ◽  
J. G. Wallace ◽  
E. R. Youngs ◽  
...  

SUMMARYIn October 1985, six cases of legionnaires' disease were associated with a police headquarters building. Four were amongst staff who worked in or visited the communications wing of the headquarters and two cases occurred in the local community. A case-control study implicated the operations room of the communications wing as the main area associated with infection. This wing was air-conditioned and smoke tracer studies showed that drift from the exhaust as well as from the base of the cooling tower entered the main air-intake which serviced the air-conditioning system.Legionella pneumophilaserogroup 1 subgroup pontiac was isolated from water and sludge in the cooling tower pond. Contaminated drift from the top of the cooling tower was probably responsible for the two community cases. An additional discovery was that symptoms suggestive of the sick-building syndrome were associated with working in this wing.


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