Infection Prevention and Control in the Podiatric Medical Setting. Challenges to Providing Consistently Safe Care

Unsafe practices are an underestimated contributor to the disease burden of bloodborne viruses. Outbreaks associated with failures in basic infection prevention have been identified in nonhospital settings with increased frequency in the United States during the past 15 years, representing an alarming trend and indicating that the challenge of providing consistently safe care is not always met. As has been the case with most medical specialties, public health investigations by state and local health departments, and the Centers for Disease Control and Prevention, have identified some instances of unsafe practices that have placed podiatric medical patients at risk for viral, bacterial, and fungal infections. All health-care providers, including podiatric physicians, must make infection prevention a priority in any setting in which care is delivered.

Infection Prevention and Control in the Podiatric Medical Setting: Challenges to Providing Consistently Safe Care

Unsafe practices are an underestimated contributor to the disease burden of bloodborne viruses. Outbreaks associated with failures in basic infection prevention have been identified in nonhospital settings with increased frequency in the United States during the past 15 years, representing an alarming trend and indicating that the challenge of providing consistently safe care is not always met. As has been the case with most medical specialties, there have been public health investigations by state and local health departments, and the Centers for Disease Control and Prevention have identified some instances of unsafe practices that have placed podiatric medical patients at risk for viral, bacterial, and fungal infections. All health-care providers, including podiatric physicians, must make infection prevention a priority in any setting in which care is delivered.

Management of neurosurgical instruments and patients exposed to Creutzfeldt-Jakob disease

OBJECTIVE

To summarize the approaches used to manage exposure of patients to inadequately sterilized neurosurgical instruments contaminated as a result of Creutzfeldt-Jakob disease (CJD).

METHODS

Information on past CJD exposure incidents reported to the Centers for Disease Control and Prevention (CDC) was aggregated and summarized. In addition, inactivation studies were reviewed, and data from selected publications were provided for reference.

RESULTS

Nineteen incidents of patient exposure to potentially CJD-contaminated instruments were reported to the CDC, including 17 that involved intracranial procedures and 2 that involved ophthalmologic procedures. In more than 50% of incidents, the neurosurgical procedures were performed for diagnostic work up of the index patients. At least 12 of the hospitals had multiple neurosurgical sets, and the CJD-contaminated instruments could not be identified in 11 of 19 hospitals. In 12 of 15 hospitals with neurosurgical incidents, a decision was made to notify patients of their potential exposure.

CONCLUSIONS

Neurosurgical instruments used for treatment of patients with suspected or diagnosed CJD or patients whose diagnosis is unclear should be promptly identified and sterilized using recommended CJD decontamination protocols. Inability to trace instruments complicates appropriate management of exposure incidents. The feasibility of instituting instrument tracking procedures should be considered.

Prevalence of antibody to hepatitis A virus in drinking water workers and wastewater workers in Texas from 1996 to 1997

To determine if wastewater workers had a higher prevalence of antibody to hepatitis A virus (anti-HAV) than drinking water workers, a convenience sample of Texas wastewater and drinking water workers was evaluated for risk factors by questionnaire and tested for anti-HAV. A total of 359 wastewater and 89 drinking water workers participated. Anti-HAV positivity was 28.4% for wastewater and 23.6% for drinking water workers. After adjustment for age, educational attainment, and Hispanic ethnicity, the odds ratio for the association between anti-HAV positivity and wastewater industry employment was 2.0 (95% confidence interval, 1.0 to 3.8). Among wastewater workers, never eating in a lunchroom, > or = 8 years in the wastewater industry, never wearing face protection, and skin contact with sewage at least once per day were all significantly associated with anti-HAV positivity in a model that adjusted for age and educational attainment. Wastewater workers in this study had a higher prevalence of anti-HAV than drinking water workers, which suggested that wastewater workers may have been at increased risk of occupationally acquired hepatitis A. Work practices that expose workers to wastewater may increase their risk.

Measles outbreak in a fully immunized secondary-school population

An outbreak of measles occurred among adolescents in Corpus Christi, Texas, in the spring of 1985, even though vaccination requirements for school attendance had been thoroughly enforced. Serum samples from 1806 students at two secondary schools were obtained eight days after the onset of the first case. Only 4.1 percent of these students (74 of 1806) lacked detectable antibody to measles according to enzyme-linked immunosorbent assay, and more than 99 percent had records of vaccination with live measles vaccine. Stratified analysis showed that the number of doses of vaccine received was the most important predictor of antibody response. Ninety-five percent confidence intervals of seronegative rates were 0 to 3.3 percent for students who had received two prior doses of vaccine, as compared with 3.6 to 6.8 percent for students who had received only a single dose. After the survey, none of the 1732 seropositive students contracted measles. Fourteen of 74 seronegative students, all of whom had been vaccinated, contracted measles. In addition, three seronegative students seroconverted without experiencing any symptoms. We conclude that outbreaks of measles can occur in secondary schools, even when more than 99 percent of the students have been vaccinated and more than 95 percent are immune.

Effect of alkaline glutaraldehyde on hepatitis B virus antigens

The potential of alkaline 2% glutaraldehyde solutions, with and without surface active agents, to alter the antigenicity of hepatitis B virus (HBV) was analyzed and compared to the antigenic alternation capacities of 0.525% sodium hypochlorite and 2.02% formaldehyde solutions. After treatment of a hepatitis B surface antigen-positive plasma at room temperature for 10 min, there was a 51-67% reduction in surface antigen level and a 90-94% decrease in hepatitis B core antigenicity. Glutaraldehyde is proposed as an alternative to the more noxious hypochlorite and formaldehyde solutions for disinfection of HBV-contaminated articles.

Immunological and biophysical alteration of hepatitis B virus antigens by sodium hypochlorite disinfection

Sodium hypochlorite (NaOCl) was examined as an effective disinfectant in hepatitis laboratories. Concentrations of NaOCl containing 5,600 ppm (5,600 microgram/ml) of available chlorine were found to be effective in destroying the antigenicity of hepatitis B surface antigen (HBsAg) in virion-rich plasma after an exposure time of 1 min or more. In the treatment of protein-deficient solutions containing HBsAg, smaller concentrations of available chlorine (less than 500 pm) are equally effective. Neither 17-to 25-nm HBsAg particles nor 45-nm virion particles could be detected by electron microscopy after treatment. chemical interaction of protein and NaOCl was confirmed by isoelectrofocusing of 125I-labeled HBsAg. More than 90% of the labeled material was found at pH 3.0 or lower, indicating complete antigen oxidation. Labeled HBsAg was reduced in density from 1.21 g/cm3 in CsCl to approximately 1.07 g/cm3 after treatment with NaOCl. Both hepatitis B core antigen and deoxyribonucleic acid polymerase activity were significantly reduced after interaction with hypochlorite solutions. These results show that NaOCl destroys hepatitis B antigenicity and virus structures and therefore may be utilized as a disinfectant for the virus.

Synthesis of transfer ribonucleic acid in KB cells infected with adenovirus type 2

The synthesis of low mol. wt. RNA has been studied in KB cells infected with adenovirus type 2 after labelling with 3H-uridine or 32P. An increasing amount of virus-coded VA RNA is detected from 8 h after infection onward. The rate of synthesis of tRNA is unchanged up to 16 h after infection and thereafter decreases; from 24 to 48 h after infection, the specific activity of tRNA is about 60% of the control value. The specific activity of cellular 5S RNA increases from 12 h after infection. When the tRNA is analysed by a two-dimensional gel electrophoresis system resolving the tRNA into 42 to 47 spots, changes in synthesis of tRNA in individual spots are seen. From 8 to 12 h after infection, an increase in the relative rate of incorporation into RNA is observed in 7 spots, while a significant decrease is detected in 8 spots. From 12 to 16 h after infection, incorporation into RNA is increased in 6 spots, but is most marked (sevenfold) in 1 spot. A decrease of incorporation into RNA in 6 spots is observed at the same time. From 24 to 34 h after infection, an increase in synthesis of RNA in 8 spots is observed and a decrease also in 8 spots. Incorporation into RNA in 2 spots is virtually shut off.