Cross-infection Control Measures Research Articles

Infection of surgical wounds in the maxillofacial region and free flap donor sites with methicillin-resistant Staphylococcus aureus

We studied the acquisition of methicillin-resistant Staphylococcus aureus (MRSA) in two groups of patients who had free flap reconstructions of defects after excision of lesions in the head and neck. The first group ( n = 31) was given a 5-day perioperative course of antibiotic prophylaxis (long-term) and the second ( n = 33) a 24-h course (short-term). MRSA was the main infecting organism. Seventeen of the 64 patients (27%) developed an infection with MRSA, including seven at donor sites of free flaps. All infections were acquired after operation, and delayed healing or discharge in five patients with MRSA and four with infections with other organisms. The median length of hospital admission was greater for patients that acquired MRSA ( p = 0.005). There were significantly fewer patients with wounds infected by MRSA in the short-term group (4/33 compared with 13/31, p = 0.01). We recommend the short-term use of an antibiotic for surgical prophylaxis and the application of cross-infection control measures on the ward.

Occupational Hazards Among Clinical Dental Staff

Although identification of risks to dental healthcare workers has been explored in several industrialized nations, very little data is available from developing countries. This paper examines the occupational hazards present in the dental environment and reports survey results concerning attitudes and activities of a group of Nigerian dental care providers. A survey on occupational hazards was conducted among the clinical dental staff at the Dental Hospital of the Obafemi Awolowo University Teaching Hospital Complex, Ile-Ife in Osun State, Nigeria. Thirty eight of the forty staff responded, yielding a response rate of 95%. Subject ages ranged from 26 to 56 years with approximately 25% in the 31-46 year old bracket. All of the staff were aware of the occupational exposure to hazards, and the majority had attended seminars/workshops on the subject. Only five staff members (13.2%) owned a health insurance policy and 26 (68.4%) had been vaccinated against Hepatitis B infection. All dentists (24) had been vaccinated compared with only two non-dentists; this relationship was significant (p= 30.07, chi2=0.000). Fourteen members of the clinical staff (36.8%) could recall a sharp injury in the past six months, and the majority (71.1%) had regular contact with dental amalgam. Wearing protective eye goggles was the least employed cross infection control measure, while backache was the most frequently experienced hazard in 47% of the subjects. The need for Hepatitis B vaccinations for all members of the staff was emphasized, and the enforcement of strict cross infection control measures was recommended. The physical activities and body positions that predispose workers to backaches were identified and staff education on the prevention of backaches was provided.

Antibiotic-resistant acne: lessons from Europe.

Propionibacterium acnes and P. granulosum are widely regarded as the aetiological agents of inflammatory acne. Their proliferation and metabolism are controlled using lengthy courses of oral and/or topical antibiotics. Despite numerous reports of skin colonization by antibiotic-resistant propionibacteria among acne patients, accurate prevalence data are available only for the U.K. To determine the prevalence of skin colonization by antibiotic-resistant propionibacteria among acne patients and their contacts from six European centres. Skin swabs were collected from 664 acne patients attending centres in the U.K., Spain, Italy, Greece, Sweden and Hungary. Phenotypes of antibiotic-resistant propionibacteria were determined by measuring the minimum inhibitory concentrations (MIC) of a panel of tetracycline and macrolide, lincosamide and streptogramin B (MLS) antibiotics. Resistance determinants were characterized by polymerase chain reaction (PCR) using primers specific for rRNA genes and erm(X), followed by nucleotide sequencing of the amplified DNA. Viable propionibacteria were recovered from 622 patients. A total of 515 representative antibiotic-resistant isolates and 71 susceptible isolates to act as control strains were characterized phenotypically. The prevalence of carriage of isolates resistant to at least one antibiotic was lowest in Hungary (51%) and highest in Spain (94%). Combined resistance to clindamycin and erythromycin was much more common (highest prevalence 91% in Spain) than resistance to the tetracyclines (highest prevalence 26.4% in the U.K.). No isolates resistant to tetracycline were detected in Italy, or in Hungary. Overall, there were strong correlations with prescribing patterns. Prevalence of resistant propionibacteria on the skin of untreated contacts of the patients varied from 41% in Hungary to 86% in Spain. Of the dermatologists, 25 of 39 were colonized with resistant propionibacteria, including all those who specialized in treating acne. None of 27 physicians working in other outpatient departments harboured resistant propionibacteria. The widespread use of topical formulations of erythromycin and clindamycin to treat acne has resulted in significant dissemination of cross-resistant strains of propionibacteria. Resistance rates to the orally administered tetracycline group of antibiotics were low, except in Sweden and the U.K. Resistant genotypes originally identified in the U.K. are distributed widely throughout Europe. Antibiotic-resistant propionibacteria should be considered transmissible between acne-prone individuals, and dermatologists should use stricter cross-infection control measures when assessing acne in the clinic.

Cross infection control measures and the treatment of patients at risk of Creutzfeldt Jakob Disease in UK general dental practice

Cross infection control measures and the treatment of patients at risk of Creutzfeldt Jakob Disease in UK general dental practice

Cross infection control measures and the treatment of patients at risk of Creutzfeldt Jakob disease in UK general dental practice.

To determine the suitability of key infection control measures currently employed in UK dental practice for delivery of dental care to patients at risk of prion diseases. Five hundred dental surgeons currently registered with the General Dental Council of the UK. Structured postal questionnaire. Frequencies, cross-tabulations and chi-squared analysis. The valid response rate to the questionnaire was 69%. 33% of practices had no policy on general disinfection and sterilisation procedures. Only 10 of the 327 responding practices (3%) possessed a vacuum autoclave. 49% of dentists reported using the BDA medical history form but less than 25% asked the specific questions recommended by the BDA to identify patients at risk of iatrogenic or familial CJD. However, 63% of practitioners would refer such patients, if identified, to a secondary care facility. Of the 107 practitioners who were prepared to provide dental treatment, 75 (70%) would do so using routine infection control procedures. Most of the dental practices surveyed were not actively seeking to identify patients at risk of prion diseases. In many cases, recommended procedures for providing safe dental care for such patients were not in place.

The human transmissible spongiform encephalopathies (TSEs): implications for dental practitioners.

Transmissible spongiform encephalopathies (TSEs) are rare, fatal degenerative brain diseases which affect humans and certain animals, and are caused by inheritance or acquisition of prions (PrPs). Inherited TSEs include Fatal Familial Insomnia (FFI), Gerstmann-Straussler-Scheinker syndrome (GSS) and other less well clinically characterised disorders, while the human infective TSEs include sporadic, iatrogenic and variant Creutzfeldt-Jakob disease (vCJD). The causative prions are found especially in neural tissues and spinal fluid, and in the case of vCJD, in lymphoreticular tissue. Available epidemiological evidence suggests that normal social or routine clinical contact with affected patients does not present a risk to health care workers, relatives or the community. Isolation of patients is not considered necessary. Nevertheless as the prions are resistant to conventional chemical, irradiation and heat sterilisation methods, highly specific cross-infection control measures are required for the dental management of patients with, or at notable risk, of TSE. The present article reviews current knowledge of the clinical consequences of prion disease and provides information regarding necessary changes to the cross-infection routine when managing patients infected, or at risk of, prion disease.

Knowledge and attitudes of dental patients towards cross-infection control measures in dental practice

The knowledge and attitudes of 460 dental patients attending outpatient dental clinics in Alexandria, Tanta, and El-Mansoura universities were studied. Every patient was interviewed individually using a questionnaire concerning the routine use of protective gloves, masks and spectacles. The results revealed that 90% of the patients expected dentists to wear gloves, 73% expected them to wear face masks and 37% to wear spectacles. Most patients believed that gloves were for the patient’s protection while face masks and spectacles were for the dentist’s protection. About 50% of patients believed that they could contract infectious diseases during dental treatment;the more educated, the greater the concern of infection. Tanta patients were more concerned about cross infection than other patients

Cross-infection compliance of UK dental staff and students.

The objectives of the study were to determine the compliance of a group of dental health care workers and students in aspects of cross-infection control. The dentists and dental students working in a dental clinic were observed by a 'hidden' ceiling-mounted video camera. Procedures were recorded onto videotape and the actions of the observed clinicians and students assessed by two suitably qualified assessors. An emergency Oral Medicine clinic in a dental hospital. Seventy nine dentists and 35 dental undergraduates. The action of staff and students were recorded on videotape and assessed retrospectively. Degree of compliance with recognised infection control policies. Compliance with recommended guidelines for control of cross-infection was poor. In only 56% of health care worker-patient contacts were protective gloves changed between patients. Facemasks and protective eyewear were only worn in 38% and 29% of such contacts respectively. Compliance with cross-infection control measures are poor in dentistry--even when clinicians are provided with appropriate facilities.

Hepatitis B vaccination: knowledge among clinical dental staff and students in Dundee.

It is now generally acknowledged that all health care workers should be vaccinated against hepatitis B. To this end, a questionnaire was sent to 132 clinical dental students and 70 staff in August 1993 at a British dental hospital, to assess their vaccination status. Approximately 10% of subjects had not completed their course of immunisation. Furthermore a significant number of subjects had failed to follow up their vaccination by an antibody titre test. Our results suggest that approximately 1 in 7 cases failed to seroconvert, emphasising that mere vaccination may not offer sufficient protection against hepatitis B. Thus adequate cross-infection control measures must be maintained in the interest of all patients.

Seroepidemiological study of respiratory virus infections among dental surgeons.

Sera were collected from 50 practising dental surgeons and 50 control subjects matched for age (+/- 1 year) and sex. Each participant completed a questionnaire including personal details and, in the case of dentists, information relating to protective work-wear and other cross-infection control measures employed within the surgery. The sera were examined by complement fixation tests for antibodies to influenza A, influenza B, respiratory syncytial virus and adenovirus. The dental group had a significantly elevated prevalence of antibodies to influenza A (P = 0.01), influenza B (P < 0.001) and respiratory syncytial virus (P = 0.001) compared with the controls. More dentists than controls also carried antibodies to adenoviruses, although this difference did not attain statistical significance. Wearing of masks or eye protection did not markedly reduce infection with these viruses among the dentists. It is concluded that dentists are at occupational risk of infection with respiratory tract viruses, and that mask- or spectacle-wearing afford little protection.

Assessment of DNA fingerprinting for rapid identification of outbreaks of systemic candidiasis.

DNA fingerprinting was assessed as an improved typing system for Candida albicans aimed at speeding the implementation of cross infection control measures in outbreaks of systemic candidiasis. The study was carried out with 45 previously characterised isolates from five different outbreaks and with 96 unrelated isolates from a mixed control population. Sixteen different genotypes were produced. Results were obtainable within days, reproducibility was high, and there was good discrimination among different outbreaks. Compared with existing typing systems DNA fingerprinting provides a robust system that may be used rapidly to identify outbreaks of nosocomial candidiasis in laboratories with no specialist skill in typing C albicans.

Klebsiella infection in a neonatal intensive care unit: role of bacteriological surveillance

An outbreak of 12 cases of infection occurred over a 9-month period in a Regional Referral Neonatal Intensive Care Unit. The pathogen was a gentamicin- and multiply-resistant Klebsiella oxytoca (K55), of high virulence. Seven of 10 neonates with septicaemia died, the majority within 24 h of the onset of infection. Screening for the resistant klebsiella revealed that 64 (39 per cent) of 164 neonates became carriers and remained so throughout their stay. Hand carriage appeared to be a mode of crosscontamination and infection. Cohorting colonized neonates together with rigorous cross-infection control measures eliminated this organism from the unit after 29 weeks. There is evidence to suggest that in one case the infecting organism was acquired from a contaminated blood gas analyser. It is necessary to use incompatibility grouping and restriction endonuclease digestion for complete characterization of plasmids and their molecular weights. However, the finding that each isolate examined carried the same five plasmids as judged by co-electrophoresis on agarose gels, and expressed the same extent and degree of transferable antibiotic resistance provides evidence to suggest that this outbreak was due to spread of a resistant clone of K. oxytoca (K55).