Shopper cards data and storage practices for the investigation of an outbreak of Shiga-toxin producing Escherichia coli O157 infections

Introduction

An outbreak of shiga-toxin producing Escherichia coli infections occurred in southwest France in June 2012. The outbreak was investigated to identify the source of infection, and guide control measures.

Methods

Confirmed outbreak cases were patients who developed bloody diarrhoea or haemolytic uremic syndrome (HUS) between 28 May and 6 July 2012, with E. coli O157 isolates showing indistinguishable patterns on pulse field gel electrophoresis (PFGE). A standardized questionnaire was administered to patients to document food consumption and other risk exposures. Their purchase was checked through their supermarket shopper card data.

Results

Six patients (four with HUS and two with bloody diarrhea) were confirmed outbreak cases. Fresh ground beef burgers from one supermarket were the only common food exposure, identified by interviews and shopper card data. The PFGE profile of shiga toxin-producing E. coli O157 isolated from the suspected beef burgers was identical to those from the human cases. The suspected beef burgers were no longer on sale at the time of investigation but three patients confirmed as outbreak cases had deep-frozen some at home.

Conclusion

Shopper card data was particularly useful to obtain precise and reliable information on the traceability of consumed food. Despite the expired use-by date, a recall was issued for the beef burgers. This contributed to preventing other cases among consumers who had deep-frozen the beef burgers.     

Outbreak of extended spectrum beta-lactamase-producing Klebsiella pneumoniae in an intensive care unit (Brest)

Introduction

We had for aim to describe control and investigation of an outbreak caused by a strain of Extended spectrum beta-lactamase producing Klebsiella pneumoniae in intensive care units of the Brest teaching hospital.

Patients and method

The case definition was a patient infected by or carrying the epidemic strain. Control measures and investigations are presented. A case-control study was conducted in the surgical intensive care unit. Each case was matched with two controls based on admission times in the unit. The study focused on diagnostic and therapeutic procedures, and potential contacts with healthcare workers, in this context of cross transmission.

Results

Between February and May 2011, nine cases were reported in the surgical ICU and two in the medical ICU. Eighteen controls were matched with the nine surgical ICU cases. Several factors were found to be statistically associated with infection or colonization by the epidemic strain: the surgical block in which patients had been operated and the ward of first hospitalization; the number of trans-esophageal and trans-thoracic echocardiographies, of central venous catheter insertions, and of surgical operations; intubation. The total number of invasive procedures was also found to be statistically higher among cases.

Conclusion

This study identified factors associated with colonization or infection by the epidemic strain. These factors might have been involved in the transmission tree, and be vulnerable elements for the prevention of nosocomial infections and colonisations, and their epidemic spread.     

Investigation and management of an imipenem-resistant oxa-23 Acinetobacter baumannii outbreak in an intensive care unit

Objectives

The study objectives were to describe the investigation and management of an imipenem-resistant Acinetobacter baumannii outbreak that occurred in the 15-bed ICU of a tertiary care teaching hospital (Brest, France), during the summer 2008.

Patients and methods

Patients harboring an imipenem-resistant A. baumannii strain were defined as case patients. We described case occurrence and steps taken to control the outbreak: contact isolation, reinforcement of hygiene procedures, unit shutdown decision, unit disinfection, and reopening. We also made a case control study and a cost analysis of the outbreak management.

Results

During a 10-day period, five patients were positive for a single clone of imipenem-resistant oxa-23 A. baumannii. Four patients presented with ventilation-acquired pneumonia and one was asymptomatic. The first two patients died one day after the first swab which led to the identification of A. baumannii. No additional case was noted in the ICU or in other hospital units after deciding to close the ICU. The cost of outbreak management was estimated at 264,553 euros. The case control study identified several factors associated with infection or colonization: length of stay in the ICU, chronic respiratory disease, number of previous antibiotic classes used, duration of ventilation, prone position, echocardiography, and presence of a nasogastric tube.

Conclusion

This outbreak occurred during the summer period requiring the shutdown of the ICU and inducing a considerable cost. Rapid reactions of the ICU staff during the outbreak enabled to limit the epidemic.     

Contribution of systematic RT-PCR screening for influenza during the epidemic season

Objective

We assessed the systematic RT-PCR screening of patients admitted to an infectious diseases department (IDD), during the 2012–2013 influenza outbreak.

Methodology

Patients admitted with cough and fever underwent a nasopharyngeal smear for RT-PCR screening.

Results

Ninety-eight patients were admitted in the IDD, from January 1st to February 22nd, 46 were screened; 11 male and 6 female patients (17.3%, mean age of 68 years) were positive. The diagnoses made in the emergency department, before RT-PCR screening, were most frequently lung infection and sepsis, but influenza in only 4 cases. The diagnosis of influenza led to stopping antibiotics (n = 4), initiating curative (n = 4) and preventive (n = 4) treatments with oseltamivir, and isolating patients to prevent a hospital outbreak.

Conclusion

Systematic RT-PCR screening allows a rapid therapeutic management and the prevention of hospital epidemic through appropriate isolation measures.     

Outbreak of Salmonella infantis gastroenteritis among people who had eaten at a hash house in southern Italy

Objectives

To describe an outbreak of acute gastroenteritis in people who had eaten at a hash house in southern Italy.

Study design

Case–control study.

Methods

A clinical case of gastroenteritis was defined as a person who had eaten at the hash house from 29 August to 4 September 2011 and who experienced defined gastrointestinal symptoms within 72 hours, or a person with a laboratory-confirmed salmonella infection without symptoms. A convenience sample was enrolled as the control group. Environmental and human samples were collected, and Salmonella infantis was identified by polymerase chain reaction. Univariate analysis was performed for each food type, and multivariate analysis was performed for each food type and demographic variable (gender, age).

Results

Twenty-three cases of gastroenteritis were notified between 1 and 4 September 2011, two of which were admitted to the local hospital. Multivariate analysis showed that porchetta [odds ratio (OR) 22.0, 95% confidence interval (CI) 3.2–152.6, z = 3.13, P = 0.002] and roasted meat (OR 14.4, 95% CI 1.7–122.0, z = 2.45, P = 0.014) were associated with gastrointestinal symptoms. Environmental and human isolates exhibited the same sequence type (ST 32).

Conclusions

This experience highlighted that, in the control of a foodborne outbreak, integrated epidemiological and laboratory surveillance enables rapid identification of the source of infection, thus reducing the risk of an epidemic.     

BCG vaccination reduces risk of infection with Mycobacterium tuberculosis as detected by gamma interferon release assay

Aims

To investigate whether BCG vaccination, in addition to a reduction of active tuberculosis, leads to a reduction of Mycobacterium tuberculosis infection during an outbreak of tuberculosis.

Methods

Pupils (n = 199) of a Junior School exposed to a pupil with active pulmonary tuberculosis were screened using a gamma interferon release assay for detection of M. tuberculosis infection (ex vivo ELISPOT assay). Relative risk of M. tuberculosis infection and pulmonary tuberculosis associated with BCG vaccination were calculated and adjusted for exposure risk.

Results

Twenty-nine percent of children with previous BCG vaccination had a reactive gamma interferon release assay compared with 47% of unvaccinated children (unadjusted RR 0.61, 95%CI 0.39, 0.96). The protective effect of BCG vaccination persisted following adjustment for other risk factors for infection like ethnicity and proximity to the source case reflected in membership of class and activity groups (corrected relative risk 0.26, 95%CI 0.09, 0.69 and risk reduction of 74%, 95%CI 31%, 91%). A higher proportion of unvaccinated children (11%) were diagnosed with active pulmonary tuberculosis compared with 5% of vaccinated children (RR 0.51 95%CI 0.15, 1.70).

Conclusion

BCG vaccination was associated with a reduction of M. tuberculosis infection diagnosed by gamma interferon release assay testing in school children during a point source outbreak.     

Staphylococcus aureus carrying Panton-Valentine leukocidin genes nasal colonization and skin infection: screening in case of outbreak in a school environment

Objectives

An outbreak of Staphylococcus aureus (SA) carrying the gene coding for Panton-Valentine leukocidin (PVL) skin infections in a primary school was investigated and monitored in the Val-d’Oise region (Greater Paris) in 2006.

Patients and methods

Skin infections reported after the beginning of the school year in primary-school teachers, students and their relatives were diagnosed and treated at the local hospital and screening for nasal colonization was implemented. A patient presenting with folliculitis, an abscess or furuncle with a positive-skin test or nasal swab for SA-PV was considered to be a case of infection. Colonization was defined as identification of SA-PVL in a nasal swab in the absence of skin lesions. In addition to recommended control measures, treatment by topical intranasal mupirocin was prescribed to all colonized patients and relatives of infected patients.

Results

Over five months, 22 cases of PVL-positive SA skin infections, including a case of simple folliculitis, were confirmed in 15 primary-school students (attack rate = 18.5%) and seven relatives. The occurrence of nasal colonization in relatives not attending the same school ranged from 0 to 30% according to the number of cases of skin infection in the family (p < 0,01). Two-thirds of patients treated with mupirocin were decolonized.

Conclusion

Transmission of this SA strain in school and family environments confirms the epidemic potential of PVL-positive isolates; however, screening for nasal colonization should be restricted to cases of skin infection and people in their immediate environment.     

Implementation of a Q fever vaccination program for high-risk patients in the Netherlands

Background

Between 2007 and 2011 the Netherlands was faced with an unprecedented Q fever outbreak with more than 4000 people affected. Dairy goats were considered the main source of infection. In addition to taking veterinary measures, the Dutch government offered an unlicensed vaccine against the causative bacterium Coxiella burnetii to patient groups at high-risk of Q fever complications. This article describes the complexity of the vaccination program for Q fever in 2010–2011.

Methods

High-risk patients were selected and referred mainly by their general practitioner to a publicly funded centralized screening and vaccination program. In addition, cardiovascular specialists and the public were informed. Patients were screened for previous infection with C. burnetii by serology and skin-tests. Patients who tested positive were excluded from vaccination.

Results

Of the 2741 referred high-risk patients (1669 male, 1957 from the high-risk area), 955 were excluded because vaccination was considered unnecessary or the distance to the vaccination clinic too far. 388 (22% of those screened) were excluded because of a positive skin-test or serology. 1368 patients (77% of those screened) were vaccinated between January and June 2011. Two-thirds of the vaccinees reported an adverse event. 89 patients (6.6%) reported serious adverse events. In just one patient, with an injection site reaction, a possible causal relationship was considered.

Conclusion

This Q fever vaccination program posed challenges to the Dutch Health Care system. Creating clarity on the roles and responsibilities of those involved precluded timely vaccination. Targeting the high-risk population through GPs was challenging but appeared to be efficient. The vaccination was considered to be safe and compliance of the screened patients was high.     

Outbreak of measles in Mayotte, Indian Ocean, 2005-2006

Objective

An outbreak of measles occurred from 2005 to 2006 in Mayotte, a French territory in the Indian Ocean. The aim of this study was to describe the outbreak, to analyze epidemiologic and sociodemographic characteristic of cases, and to suggest recommendations for measles surveillance and preventive measures in Mayotte.

Design

An outbreak investigation was conducted and an enhanced passive surveillance system of incident cases was implemented.

Results

During the outbreak, 1269 clinical cases, including 156 (12.3%) biologically confirmed cases, were reported. The attack rate was 0.71% and no death due to measles was recorded. The median age of cases was 12 years and the M/F sex-ratio 1.1. Teenagers and young adults (10–19 years) were the most frequently affected (44.4%) and infants less than one year of age accounted for 21.6% of the cases. In the 1269 clinical cases, 27.3% of patients had received at least one dose of measles vaccine before the outbreak. The immunization coverage in school children reached 59.1% at the end of the vaccination campaign.

Conclusion

In the future, this vaccinal coverage should be improved to prevent other outbreaks, especially in vulnerable groups like immigrants. A surveillance system with systematical report of the biologically confirmed cases is needed in Mayotte.     

Antibacterial and antifungal activity of lawsone and novel naphthoquinone derivatives

Introduction

Naphthoquinone derivatives are under investigation as potential therapeutic agents. The antibacterial and antifungal activity of lawsone and of some novel naphthoquinone derivatives was assessed in vitro.

Methods

The antimicrobial activity was determined using diffusion disk and the broth microdilution methods against seven bacteria and three Candida species, according to recommendations of the Clinical and Laboratory Standards Institute.

Results

Two compounds (P05 et P06) presented a good antibacterial effectiveness against two gram-positive bacteria. No antifungal potency was observed against the three Candida albicans strains used in the test.

Conclusion

Our results prove that the introduction of substituents on ketone function position 4 decreased the antimicrobial properties of the synthetized compounds.     

Impact of drought on vector-borne diseases – how does one manage the risk?

Objectives

This article aimed to review all literature on drought and vector-borne disease to enable an assessment of the possible impact of drought on the changing risk of vector-borne diseases in the UK.

Study design

A systematic literature review was performed.

Methods

Using a search strategy developed from a combination of terms for drought and selected outcomes, the authors systematically reviewed all available literature from 1990 to 2012 on the impact of drought on vector-borne diseases. The following databases were searched: PubMed, Web of Science, and EMBASE. After reviewing the abstracts, 38 articles were found to fit the inclusion and exclusion criteria.

Results

Evidence found drought followed by re-wetting can have a substantial effect on water table levels, vegetation, and aquatic predators; all factors which influence mosquito populations. Several studies found an association between a drought during the previous year and West Nile virus incidence. Urban mosquito vectors of dengue virus and chikungunya virus are adaptable by nature and are able to exploit a multitude of additional aquatic habitats created as a response to drought (i.e. water storage containers). Tick populations are likely to be negatively affected by drought as they are dependent upon high levels of humidity and soil moisture.

Conclusions

Further research is needed to identify public health interventions and environmental control measures for an invasive mosquito problem or arthropod-borne disease outbreak in the UK.     

Challenges in confirming a varicella outbreak in the two-dose vaccine era

Background

A second dose of varicella vaccine was recommended for U.S. children in 2006. We investigated a suspected varicella outbreak in School District X, Texas to determine 2-dose varicella vaccine effectiveness (VE).

Methods

A varicella case was defined as an illness with maculopapulovesicular rash without other explanation with onset during April 1–June 10, 2011, in a School District X student. We conducted a retrospective cohort in the two schools with the majority of cases. Lesion, saliva, and environmental specimens were collected for varicella-zoster virus (VZV) PCR testing. VE was calculated using historic attack rates among unvaccinated.

Results

In School District X, 82 varicella cases were reported, including 60 from Schools A and B. All cases were mild, with a median of 14 lesions. All 10 clinical specimens and 58 environmental samples tested negative for VZV. Two-dose varicella vaccination coverage was 66.4% in Schools A and B. Varicella VE in affected classrooms was 80.9% (95% CI: 67.2–88.9) among 1-dose vaccinees and 94.7% (95% CI: 89.2–97.4) among 2-dose vaccinees in School A, with a second dose incremental VE of 72.1% (95% CI: 39.0–87.3). Varicella VE among School B students did not differ significantly by dose (80.1% vs. 84.2% among 1-dose and 2-dose vaccinees, respectively).

Conclusion

Laboratory testing could not confirm varicella as the etiology of this outbreak; clinical and epidemiologic data suggests varicella as the likely cause. Better diagnostics are needed for diagnosis of varicella in vaccinated individuals so that appropriate outbreak control measures can be implemented.     

Défaut de couverture vaccinale pneumococcique chez l’adulte à risque

Objective

This study had for aim to assess pneumococcal vaccination rates in hospitalized patients.

Design

A prospective study was carried out in two medical wards of the Nice University Hospital, France. Patients were included from December 31, 2007 to February 12, 2008.

Results

Hundred and thirty-seven patients, aged 62 ± 20 years, were included. Pneumococcal vaccination was indicated for 62 patients (45 %). Among these 62 patients, 53 (85 %) had not been vaccinated in the previous 5 years, for the following reasons: no medical advice on vaccination (36 cases), no medical consultation in the past years (nine cases), patient opposed to vaccination (two cases), physician opposed to vaccination (one case), miscellaneous (five cases). Among the 53 patients, seven were vaccinated during their hospital stay and 13 were advised to be vaccinated by their general practitioner.

Conclusions

This study highlights a low rate of pneumococcal vaccination in hospitalized patients, mainly due to insufficient counseling from physicians, both in community or in hospital practice.     

Influenza H3N2 variant viruses with pandemic potential: Preventing catastrophe in remote and isolated Canadian communities

Objective

To evaluate the impact of age-specific cross-reactive antibody protection levels on the outcomes of a pandemic outbreak of new variants of H3N2 influenza A viruses (H3N2v).

Methods

We calibrated a previously validated agent-based model of human-to-human transmission of influenza viruses to project the outcomes of various protection levels in a remote and isolated Canadian community, when demographics are drawn from the Statistics Canada census data. We then compared the outcomes with a scenario in which demographic variables were shifted to resemble an urban structure. This comparative evaluation was conducted using in-silico computer simulations, where the epidemiological data were drawn from relevant estimates in published literature.

Results

Simulations, using estimates of transmissibility for the 2009 H1N1 pandemic strain in the study population, show that the epidemic size is primarily affected by the cross-reactive protection levels of young children. A lower number of secondary infections at the early stages of an outbreak does not necessarily correspond to a lower epidemic size.

Conclusions

Demographic variables could play a significant role in determining the outcomes of an outbreak. The findings strongly suggest that, when an H3N2v-specific vaccine becomes available, children below the age of 17 should be prioritized for vaccination. This prioritization is essential in population settings with a low average age, including aboriginal communities in northern latitudes.     

Skin and soft tissue infections due to Panton–Valentine leukocidin producing Staphylococcus aureus

Objective

The authors had for aim to describe the epidemiological and clinical characteristics, and the treatment of patients presenting with skin and soft tissue infections due to Panton–Valentine leukocidin (PVL) producing Staphylococcus aureus in the Nord-Pas-de-Calais (NPDC) region, North of France.

Methods

We included patients presenting with PVL producing S. aureus infection from seven hospitals in the NPDC region, between February 2004 and April 2008. We retrospectively collected patient data using a standardized questionnaire. The features of patients presenting with skin and soft tissue were then analyzed.

Results

PVL producing S. aureus was isolated from 64 patients. Fifty-four patients presented with skin and soft tissue infections. The mean age of patients was 23.8 years (63% male patients). The mean number of persons living with the infected patient was 4.5 (vs. 2.5 in NPDC). The lesions were abscesses with inflammatory signs in 64.8% of the cases (20% were necrotic). Among the patients, 70.3% carried a methicillin resistant strain. Antibiotics per os were used for 83.3% of patients; the first-line antibiotics were considered inadequate in 53.3% of the cases. Among the patients, 83.3% underwent surgery. Fourteen out of 38 patients with available data had been exposed to antibiotic therapy during the three months before hospital management.

Conclusion

Recent exposure to antibiotics and living with a high number of persons are reasons to suspect a PVL producing S. aureus infection in patients with skin abscess.     

Accuracy of providers' assessment of pain during intrauterine device insertion

Background

Providers often underestimate patient pain. This study investigated if providers accurately assess pain during intrauterine device (IUD) insertion.

Study Design

This is a secondary analysis of a randomized trial. Participants rated pain on a 100-mm visual analogue scale (VAS). Providers marked a similar VAS for maximum level and timing of participant pain.

Results

The mean patient maximum pain was 64.8 mm (SD, 27) compared to 35.3 mm (SD, 26) rated by the provider (p<.001). Patient and provider agreement on most painful time point of procedure was weak (kappa statistic, 0.16).

Conclusions

Providers underestimate pain during IUD insertion.

Implications

To our knowledge, this is the first paper to compare provider and patient perceptions of pain during IUD insertion. Understanding this relationship will help guide further research about IUD insertion pain and techniques and could improve patient counseling.     

Localisation hépatique de la maladie des griffes du chat chez un immunocompétent

Introduction

The cat-scratch disease is a benign inoculation disease and a well-known cause of localized lymphadenopathy. Visceral localizations are rare and occur mostly in immunocompetent patients.

Case

We report the case of a 57-year-old-man with lymphadenopathy of the right arm with hepatic nodules related to a Bartonella henselae infection.

Conclusion

The cat-scratch disease must be screened for in case of hepatic and/or splenic nodules. A cause of immunodeficiency should be investigated.     

Economic impact of the 2009–2010 Guam mumps outbreak on the public health sector and affected families

Background

The United States Territory of Guam reported a large mumps outbreak of 505 cases during 2009–2010. We assessed the economic impact of the outbreak from the perspectives of the local public health sector and affected families.

Methods

Using standard cost analysis methods, we retrospectively identified all public health personnel involved in the outbreak response and surveyed them about their outbreak-related activities. We then estimated the costs of outbreak-related personnel hours and materials. We also assessed out-of-pocket costs and costs incurred for work-time missed for persons with mumps and their families. We defined the analysis period as February 25–October 22, 2010.

Results

Seventy-six public health personnel were involved in outbreak response activities. Overall, the response required approximately 8264 person-hours, 2380 miles driven, and 3000 doses of measles-mumps-rubella vaccine ordered. The cost to the public health sector was 256,785 U.S. dollars (USD). Families of 102 persons with mumps were interviewed. An estimated 761 USD per person with mumps was spent by families; 88% of this cost was due to missed days of work. The estimated total cost to families of the 470 persons with mumps during the analysis period was 357,670 USD. Total outbreak-related costs were 614,455 USD.

Conclusions

The costs reported underscore the impact of mumps outbreaks in highly vaccinated populations and the need for effective mumps prevention and control strategies.