Molecular epidemiology of Burkholderia cepacia in two Australian cystic fibrosis centres.
Paul ML. Pegler MA. Benn RA.
Department of Microbiology, Royal Prince Alfred Hospital, Camperdown, NSW, Australia.
Forty individual patient sputum isolates of Burkholderia cepacia from two Australian cystic fibrosis (CF) centres more than 100 km apart were genotyped using pulsed-field gel electrophoresis (PFGE) with XbaI restriction enzyme digestion. Hospital 1 had an endemic strain with 19 of 20 isolates being closely related. This centre does not implement an inpatient segregation policy for its paediatric patients who constitute the majority of those colonized with B. cepacia. Hospital 2 did not have a single endemic strain; there were two different sibling clusters and a third cluster involving a cohabiting couple, but all other patients had unique isolates. One patient at Hospital 2 carried an organism closely related to the endemic strain from Hospital 1. Hospital 2 practises segregation of colonized inpatients and also segregation external to the hospital. It would appear that no nosocomial spread of infection is occurring with this policy.
Recurrence of symptoms in Clostridium difficile infection--relapse or reinfection?
Wilcox MH. Fawley WN. Settle CD. Davidson A.
Department of Microbiology, University of Leeds, UK.
We have fingerprinted Clostridium difficile isolates from patients with symptomatic recurrences of infection, using random amplified polymorphic DNA (RAPD). The medical records of 55/79 patients were examined, from whom multiple C. difficile-positive faeces were received during hospitalization at least five days, but no more than two months, apart. In 20 of these cases symptoms either did not recur (i.e., absent for at least three days between episodes), or were explainable by other causes, such as laxative administration. Of the remaining 35 patients, 27 sets of C. difficile isolates (23 pairs and four triplicates) were available for RAPD fingerprinting. Differing C. difficile DNA fingerprints (at least three major bands difference) were obtained for 15/27 patients, and hence at least 56% of the clinical recurrences of infection were in fact due to re-infection as opposed to relapse. Since we found that an endemic C. difficile clone was present in 18 out of 27 patients (67%) and accounted for 53% (31/58) of all isolates, it is probable that the majority of symptomatic recurrences are in fact re-infections, with either a different or the same C. difficile strain. We conclude that more attention must be given to preventing the re-infection of C. difficile symptomatic patients. Isolation of symptomatic individuals is the preferred option for the protection of other patients, but measures must be taken to ensure that further strain acquisition by the index cases does not occur.
Simultaneous outbreaks of two strains of toxigenic Clostridium difficile in a general hospital.
Kyne L. Merry C. O'Connell B. Harrington P. Keane C. O'Neill D.
Department of Medicine for the Elderly, St James's Hospital, Dublin, Ireland.
We report an outbreak of Clostridium difficile-associated disease (CDAD) in a large Dublin hospital. From January to June 1995, inclusive, 139 patients were affected; the mean age of cases was 68.8 +/- 19 years. Clinical information is available for 73 cases identified during the first four months of the outbreak. The majority of patients presented with abrupt onset of watery diarrhoea; however, 19.2% presented with an unexplained pyrexia following a course of antimicrobial therapy and 5.5% presented with a surgical acute abdomen. Twenty patients (27.4%) experienced relapsing disease and seven (9.6%) patients died. Seventy-six percent of cases received a cephalosporin prior to the onset of disease, the highest relative risks occurring with third-generation agents; however, 9.6% of patients affected had not been exposed to antimicrobial therapy in the preceding eight weeks. Pyrolysis mass spectrometry identified two clusters of isolates, representing two strains of C. difficile. There was marked spatial clustering of these strains, with each confined to a separate area of the hospital. Infection control measures and an antibiotic policy were introduced. Throughout the outbreak period the use of the most frequently used cephalosporin in the hospital increased; this was accompanied paradoxically by a reduction in the number of new cases of CDAD.
Frequency of parenteral exposure and seroprevalence of HBV, HCV, and HIV among operation room personnel.
Mujeeb SA. Khatri Y. Khanani R.
Blood Transfusion Services, Jinnah Postgraduate Medical Centre, Karachi, Pakistan.
A study was designed to determine the frequency of needle-stick injuries, immunization status for hepatitis B virus (HBV) and sero-prevalence of HBV, hepatitis C virus (HCV), and human immunodeficiency virus (HIV) infections among operation room personnel. Self-assessment questionnaires were completed and blood tested for HBsAg, anti-HBc (total), anti-HCV and anti-HIV. Of 114 operation room personnel studied, the majority (58.8%) reported more than four needle-stick injuries per year, 36.8% one to three needle-stick injuries per year, while 4.4% reported no needle-stick injury in the last five years. Thirty-six percent of personnel had received a complete course of hepatitis B vaccination. There was serological evidence of hepatitis HBV virus and/or HCV infections in 31% of the studied population. Four percent were reactive for HCV infection, 7.5% for HBsAg infection and 25.43% for anti-HBc (total); none was HIV positive. Eighty percent of the HCV positive and 55% of the anti-HBc (total) positive personnel had more than four needle-stick injuries per year in the last five years, while 75% HBsAg-reactive personnel had received one to three needle-stick injuries per year. This study indicates a need for continued efforts to minimize the risk of blood-borne infection by enhancing the compliance of operation room personnel with HBV vaccination and adherence to infection control measures.
Growth and enterotoxin production by diarrhoeagenic Bacillus cereus in dietary supplements prepared for hospitalized HIV patients.
Rowan NJ. Anderson JG.
Department of Bioscience and Biotechnology, University of Strathclyde, Glasgow, Scotland.
This study was initiated because of an increase in diarrhoeal episodes in a ward caring for patients infected with the human immunodeficiency virus (HIV). An examination of hospital-prepared dietary supplements (build-up food) found Bacillus cereus to be a potential problem. Due in part to inadequate refrigeration conditions (13 +/- 4 degrees C), the microbial flora in commercially pasteurized semi-skimmed milk (PSSM) reached potentially hazardous levels (> 10(6) cfu/mL). While refrigerated PSSM did not support enterotoxin production, reconstitution of build-up powder in PSSM followed by storage in the HIV ward (4 h at 28 +/- 3 degrees C) resulted in growth of B. cereus (> 10(7) cfu/mL) and synthesis of diarrhoeal enterotoxin. While insufficient epidemiological data was available to establish conclusively a causal relationship between patients' symptoms and source, the study highlights a potential B. cereus problem with hospital-prepared dietary supplements and recommendations are proposed to prevent this re-occurrence.
Hospital-acquired infection in elderly patients.
Taylor ME. Oppenheim BA.
Public Health Laboratory, Withington Hospital, West Didsbury, Manchester, UK.
Increasing numbers of elderly people are being treated in hospitals and are at particular risk of acquiring infections. The incidence, risk factors and types of hospital-acquired infection (HAI) in the elderly are reviewed. Special reference is made to urinary tract infections, respiratory tract infections, gastrointestinal infections including Clostridium difficile, bacteraemia, skin and soft tissue infections and infections with antibiotic-resistant organisms.
The role of environmental contamination with small round structured viruses in a hospital outbreak investigated by reverse-transcriptase polymerase chain reaction assay.
Green J. Wright PA. Gallimore CI. Mitchell O. Morgan-Capner P. Brown DW.
Enteric and Respiratory Virus Laboratory, Central Public Health Laboratory, London, UK. email@example.com
In May 1994 an outbreak of vomiting and diarrhoea occurred in a 28-bed long-stay ward for the mentally infirm. The predominant symptoms were vomiting, diarrhoea, malaise and abdominal pain lasting for approximately 12 h in most cases. The attack rate was 62% (13/21) for patients and 46% (16/35) for staff members. Infection control measures were implemented (containment of infectious individuals, hand hygiene among staff and environmental decontamination) and the ward was closed to admissions. Affected staff were excluded from contact with patients and their food until asymptomatic for 72 h. The outbreak lasted for 17 days. Faecal samples from nine symptomatic persons were negative for bacterial enteric pathogens, Giardia, Cryptosporidium and group A rotavirus. Electron microscopy of 12 faecal samples and one sample of vomitus revealed small round structured virus (SRSV) particles in one faecal sample. A further 30 faecal samples and seven vomitus samples were tested by reverse transcription polymerase chain reaction (RT-PCR) for SRSV of which 12 (40%) and 1 (14%) were positive respectively. Twenty-eight throat swabs from symptomatic and asymptomatic patients were collected, three (9.5%) of which were positive for SRSV by RT-PCR. Thirty-six environmental swabs were collected on the affected ward, and 11 (30%) were positive by RT-PCR. Positive swabs were from lockers, curtains and commodes and confined to the immediate environment of symptomatic patients. The distribution of contamination supports the rationale of cohorting sick patients.