Current issues and update on human immunodeficiency virus infection in the orthopaedic setting.

The risk of HIV transmission in the health care setting is a composite of risks, with exposure to blood being the most important source of infection and percutaneous injuries posing the greatest risk of transmission. The frequency of blood contact varies by occupation, procedure performed, and precautions used. Data suggest that PEP may be effective in reducing the risk of occupational HIV transmission. The risk for transmission of HIV from HCW to patients is very small.

Experience of healthcare workers taking postexposure prophylaxis after occupational HIV exposures: findings of the HIV Postexposure Prophylaxis Registry.

OBJECTIVE: To collect information about the safety of taking antiretroviral drugs for human immunodeficiency virus (HIV) postexposure prophylaxis (PEP). DESIGN: A voluntary, confidential registry. SETTING: Hospital occupational health clinics, emergency departments, private physician offices, and health departments in the United States. RESULTS: 492 healthcare workers (HCWs) who had occupational exposures to HIV, were prescribed HIV PEP, and agreed to be enrolled in the registry by their healthcare providers were prospectively enrolled in the registry. Three hundred eight (63%) of 492 of the PEP regimens prescribed for these HCWs consisted of at least three antiretroviral agents. Of the 449 HCWs for whom 6-week follow-up was available, 195 (43%) completed the PEP regimen as initially prescribed. Forty-four percent (n=197) of HCWs discontinued all PEP drugs and did not complete a PEP regimen. Thirteen percent (n=57) discontinued > or =1 drug or modified drug dosage or added a drug but did complete a course of PEP Among the 254 HCWs who modified or discontinued the PEP regimen, the two most common reasons for doing so were because of adverse effects attributed to PEP (54%) and because the source-patient turned out to be HIV-negative (38%). Overall, 340 (76%) HCWs with 6-week follow-up reported some symptoms while on PEP: nausea (57%), fatigue or malaise (38%), headache (18%), vomiting (16%), diarrhea (14%), and myalgias or arthralgias (6%). The median time from start of PEP to onset of each of the five most frequently reported symptoms was 3 to 4 days. Only 37 (8%) HCWs with 6-week follow-up were reported to have laboratory abnormalities; review of the reported abnormalities revealed that most were unremarkable. Serious adverse events were reported to the registry for 6 HCWs; all but one event resolved by the 6-month follow-up visit. Fewer side effects were reported by HCWs taking two-drug PEP regimens than by HCWs taking three-drug PEP regimens. CONCLUSIONS: Side effects from HIV PEP were very common but were rarely severe or serious. The nature and frequency of HIV PEP toxicity were consistent with information already available on the use of these antiretroviral agents. Clinicians prescribing HIV PEP need to counsel HCWs about PEP side effects and should know how to manage PEP toxicity when it arises.

Investigations of patients of health care workers infected with HIV. The Centers for Disease Control and Prevention database.

OBJECTIVE: To assess the risk for transmission of the human immunodeficiency virus (HIV) from an infected health care worker to patients. DESIGN: Survey of investigators from health departments, hospitals, and other agencies who had elected to notify patients who had received care from health care workers infected with HIV. MEASUREMENTS: Information was collected about infected health care workers, their work practices, their patients' HIV test results, procedures that they did on those of their patients who were tested for HIV, and patient notification procedures. RESULTS: As of 1 January 1995, information about investigations of 64 health care workers infected with HIV was reported to the Centers for Disease Control and Prevention; HIV test results were available for approximately 22,171 patients of 51 of the 64 health care workers. For 37 of the 51 workers, no seropositive patients were reported among 13,063 patients tested for HIV. For the remaining 14 health care workers, 113 seropositive patients were reported among 9108 patients. Epidemiologic and laboratory follow-up did not show any health care worker to have been a source of HIV for any of the patients tested. CONCLUSION: Despite limitations, these data are consistent with previous assessments that state that the risk for transmission of HIV from a health care worker to a patient is very small. These data also support current recommendations that state that retrospective patient notification need not be done routinely.

Serosurvey of human immunodeficiency virus, hepatitis B virus, and hepatitis C virus infection among hospital-based surgeons. Serosurvey Study Group.

BACKGROUND: Because occupational blood contact places health-care workers at risk for infection with bloodborne pathogens, we wanted to estimate the prevalence of infection with human immunodeficiency virus (HIV), hepatitis B virus (HBV), and hepatitis C virus (HCV) among hospital-based surgeons and correlate the results with occupational and nonoccupational risk factors. STUDY DESIGN: All surgeons in training or in practice in general surgery, obstetrics and gynecology, or orthopedics at 21 hospitals in moderate to high AIDS incidence areas were eligible to participate in a voluntary, anonymous serosurvey. Serum samples were tested for HIV antibody, for HCV antibody, and for markers of HBV infection: hepatitis B surface antigen, total antibody to hepatitis B core antigen, and antibody to hepatitis B surface antigen. RESULTS: Of 2,887 eligible surgeons, 770 (27 percent) participated in the study. One of 740 surgeons not reporting nonoccupational risk factors was HIV seropositive (0.14 percent, upper limit 95 percent confidence interval [CI] equals 0.64 percent). None of 20 participants reporting nonoccupational HIV risk factors and none of ten not responding to the question on nonoccupational risk factors were HIV positive. Of 129 (17 percent) participants with past or current HBV infection, three (0.4 percent) had chronic HBV infection; all were negative for hepatitis B e antigen. Risk factors for HBV infection included not receiving hepatitis B vaccine (odds ratio [OR] 14.7, 95 percent CI 8.3 to 26.0) and practicing surgery at least ten years (OR 2.2, 95 percent CI 1.3 to 3.8). Seven (0.9 percent) participants had anti-HCV. CONCLUSIONS: Although not necessarily generalizable to all surgeons in moderate to high AIDS incidence areas, these results do not indicate a high rate of previously undetected HIV infection among surgeons who trained or practiced in these areas, or both. Hepatitis B virus posed the highest risk of infection with a bloodborne pathogen, followed by HCV and HIV.

Methicillin-resistant Staphylococcus aureus in U.S. hospitals, 1975-1991.

OBJECTIVES: Analyze changes that have occurred among U.S. hospitals over a 17-year period, 1975 through 1991, in the percentage of Staphylococcus aureus resistant to beta-lactam antibiotics and associated with nosocomial infections. DESIGN: Retrospective review. The percentage of methicillin-resistant S aureus (MRSA) was defined as the number of S aureus isolates resistant to either methicillin, oxacillin, or nafcillin divided by the total number of S aureus isolates for which methicillin, oxacillin, or nafcillin susceptibility test results were reported to the National Nosocomial Infections Surveillance (NNIS) System. SETTING: NNIS System hospitals. RESULTS: Of the 66,132 S aureus isolates that were tested for susceptibility to methicillin, oxacillin, or nafcillin during 1975 through 1991, 6,986 (11%) were resistant to methicillin, oxacillin, or nafcillin. The percentage MRSA among all hospitals rose from 2.4% in 1975 to 29% in 1991, but the rate of increase differed significantly among 3 bed-size categories: < 200 beds, 200 to 499 beds, and > or = 500 beds. In 1991, for hospitals with < 200 beds, 14.9% of S aureus isolates were MRSA; for hospitals with 200 to 499 beds, 20.3% were MRSA; and for hospitals with > or = 500 beds, 38.3% were MRSA. The percentage MRSA in each of the bed-size categories rose above 5% at different times: in 1983, for hospitals with > or = 500 beds; in 1985, for hospitals with 200 to 499 beds; and in 1987, for hospitals with < 200 beds. CONCLUSIONS: This study suggests that hospitals of all sizes are facing the problem of MRSA, the problem appears to be increasing regardless of hospital size, and control measures advocated for MRSA appear to require re-evaluation. Further study of MRSA in hospitals would benefit our understanding of this costly pathogen.

Blood and amniotic fluid contact sustained by obstetric personnel during deliveries.

OBJECTIVE: The objective of this study was to characterize blood and amniotic fluid contact sustained by obstetric personnel during deliveries. STUDY DESIGN: Trained observers collected data on 1376 person procedures during 230 deliveries at Grady Memorial Hospital from May to October 1989. Rates of contact were compared by means of the chi 2 test. RESULTS: At least one blood or amniotic fluid contact occurred during 79 (39.1%) of 202 vaginal and 14 (50.0%) of 28 cesarean deliveries; a needle stick occurred in 4 (2.0%) of the vaginal deliveries. Obstetricians and midwives had the highest rates of blood and amniotic fluid contact (18.7% and 28.8% of person procedures, respectively). Half of the contacts sustained by midwives might have been prevented by the use of gowns. Most contacts sustained by obstetricians might have been prevented by face shields, impervious gowns, and impervious shoe covers. CONCLUSIONS: Obstetricians and midwives had substantial risk of blood and amniotic fluid contact during delivery; many of their contacts were potentially preventable.

Infections and pseudoinfections due to povidone-iodine solution contaminated with Pseudomonas cepacia.

In 1989 we investigated the first instance of Pseudomonas cepacia infections due to intrinsic contamination of a povidone-iodine product. Six patients in a Texas pediatric facility had P. cepacia infection or pseudoinfection (three, peritonitis; one, pseudoperitonitis; and two, pseudobacteremia). Epidemiological studies showed one risk factor for infection of peritoneal fluid with P. cepacia: performance of peritoneal dialysis in the dialysis unit with use of one lot of povidone-iodine later found to be intrinsically contaminated (4/5 vs. 0/16, P = .001). Blood cultures yielded P. cepacia after nurses wiped the tops of blood culture bottles with the povidone-iodine solution before inoculation. P. cepacia was cultured from three povidone-iodine containers used at the hospital and from four containers of the same lot obtained from other health-care facilities in Texas and California. Isolates from patients and the povidone-iodine had similar antibiograms, identical plasmid profiles, and identical DNA banding patterns on the basis of results of ribonucleotide typing. This investigation demonstrates that intrinsic contamination of povidone-iodine solution with P. cepacia can result in infections in addition to colonization and/or pseudoinfection.

Isoenzyme analysis of Pseudomonas cepacia as an epidemiologic tool.

Multilocus enzyme electrophoresis has successfully been used to establish basic marker systems for the epidemiologic analysis of a variety of bacterial pathogens. This study was done to determine the efficacy of this technique for characterizing Pseudomonas cepacia, using 31 known-related strains isolated during an outbreak of infections involving intrinsically contaminated povidone-iodine solution, and five outbreak-unrelated strains used in serotyping of P. cepacia. Crude cell extracts were analyzed by starch gel electrophoresis for electrophoretic variants using 13 enzyme substrates; esterase bands were detected using an additional four substrates. The 31 outbreak strains had identical isoenzyme patterns for all enzymes examined. Five electrophoretic types were obtained for the serotyping strains; electrophoretic mobilities of one of the five strains corresponded to the patterns obtained for the outbreak strains. These results suggest that enzyme electrophoretic typing may be a useful adjunct to other typing methods used in epidemiologic analyses of P. cepacia infections.

Investigations of intrinsic Pseudomonas cepacia contamination in commercially manufactured povidone-iodine.

OBJECTIVE: Laboratory investigations were initiated with a povidone-iodine antiseptic solution that was intrinsically contaminated with Pseudomonas cepacia. These investigations were helpful in understanding the microbicidal and chemical properties of iodophor solutions and the mechanism by which P cepacia can survive in iodine-containing antiseptics. DESIGN: Included in these studies were: prolonged survival of P cepacia; available and free iodine determinations; microbial challenge studies; and scanning electron microscopic examination of contaminated antiseptic. RESULTS: P cepacia survived in this iodophor antiseptic up to 68 weeks from the date of manufacture. A uniform concentration of 1% available iodine was found in all lots of povidone-iodine tested as specified on the product label, but free iodine (I2) values varied greatly. Low free iodine levels of 0.23 to 0.46 ppm were associated with the contaminated lot of povidone-iodine. Solutions of povidone-iodine with varying levels of free iodine were rapidly microbicidal when challenged with cells of P cepacia derived from culture broth and washed or adapted to growth in water. P cepacia cells taken directly from contaminated povidone-iodine survived for significantly longer periods of time. Large numbers of P cepacia were found embedded in extracellular material and among strands of glycocalyx between cells as shown by scanning electron microscopy. CONCLUSIONS: The physical thickness of cellular and extracellular material that forms on surfaces could protect embedded organisms from the microbicidal action of disinfectants and antiseptics and subsequently allow for extended microbial survival times. Manufacturers should be aware that distribution piping surfaces colonized with bacteria may be a source of product contamination and resistant organisms.

Blood contacts during surgical procedures.

Operating room personnel are at risk for infection with blood-borne pathogens through blood contact. To describe the nature and frequency of blood contact and its risk factors, trained observers monitored a sample of operations performed by six surgical services at Grady Memorial Hospital, Atlanta, Ga, for 6 months. In 62 (30.1%) of 206 operations, at least one blood contact was observed. Of 1828 operating room person-procedures observed, 96 (5.3%) had 147 blood contacts (133 skin contacts [90%], 10 percutaneous injuries [7%], and four eye splashes [3%]). The mean number of blood contacts per 100 person-procedures was highest for surgeons (18.6). The frequency of percutaneous injury was similar among surgeons and scrub staff (mean, 1.2 per 100 worker-procedures for each group). Risk factors for surgeons' blood contacts were (1) performing a trauma, burn, or orthopedic emergency procedure (odds ratio [OR], 4.1; 95% confidence interval [CI], 2.0 to 8.7); (2) patient blood loss exceeding 250mL (OR, 2.1; 95% CI, 1.2 to 3.7); and (3) being in the operating room longer than 1 hour (OR, 3.3; 95% CI, 1.6 to 7.1). Of 110 blood contacts among surgeons, 81 (74%) were potentially preventable by additional barrier precautions, such as face shields and fluid-resistant gowns. Twenty-one (84%) of 25 blood contacts among surgeons in procedures in which all three risk factors were present were potentially preventable by additional barriers. Of 29 blood contacts among anesthesia and circulating personnel, 20 (69%) would have been prevented by glove use. For surgical procedures in which operating room personnel are at increased risk of blood contact, reevaluation of surgical technique, use of appropriate barrier precautions, and development of puncture-resistant glove materials are indicated.

Prolonged survival of Pseudomonas cepacia in commercially manufactured povidone-iodine.

Pseudomonas cepacia organisms were recently recovered from a povidone-iodine antiseptic solution. During the subsequent investigation, laboratory studies were initiated to determine the survival time of these organisms in the iodophor solution, which contains 1% titratable iodine. The solution was sampled weekly upon receipt in our laboratory, and P. cepacia was subsequently recovered through 29 weeks of sampling. Current laboratory data and lot production date information from the manufacturer indicate that P. cepacia survived for up to 68 weeks from the time of manufacture. Scanning electron microscopic examination of contaminated solution demonstrated bacterial cells embedded in extracellular material.

Sepsis associated with transfusion of red cells contaminated with Yersinia enterocolitica.

Between April 1987 and May 1989, the Centers for Disease Control investigated seven cases of transfusion-associated Yersinia enterocolitica sepsis; four were caused by organisms of serotype O:3, and one each was caused by organisms of serotype O:1,2,3; O:5,27; and O:20. All seven recipients developed septic shock after receiving units of red cells (RBCs) contaminated with Y. enterocolitica; five recipients died. The cases occurred in seven states and were unrelated. There was no evidence for contamination of the RBC units during processing. Six of the seven donors had serologic evidence of recent Y. enterocolitica infection, and it is hypothesized that these donors had asymptomatic bacteremia when they donated the implicated blood. Four of the seven donors reported gastrointestinal illness in the 4 weeks before blood donation, and one donor became ill on the day he donated blood. Y. enterocolitica grows well at 4 degrees C and in the presence of dextrose and iron. If blood is contaminated at the time of collection, storage of the RBCs at 4 degrees C provides an ideal environment for bacterial growth and endotoxin production. These cases demonstrate the need for careful evaluation of patients with transfusion reactions for possible sepsis and suggest a need to screen prospective blood donors for mild gastrointestinal illness, including those illnesses not requiring physician evaluation or medication.

Therapeutic plateletpheresis in thombocythemia.

Patients with myeloproliferative thrombocythemia have usually been managed with chemotherapy. Generally, removal of platelets from such patients has been performed intermittently to lower the platelet mass rapidly when neurologic or hemorrhagic complications were manifest or concurrently with the initiation of chemotherapy. A platelet count of 1,000,000/microliter or less was maintained by the use of repeated plateletpheresis over a period of three months in a patient with essential thrombocythemia, who had frequent syncopal episodes. A second patient with secondary thrombocytosis, who sustained two cerebrovascular accidents, underwent intermittent plateletpheresis over a 22-day period until her underlying disorder improved. It is concluded from the experience, combined with that of others, that plateletpheresis is not only a life-saving procedure in an acute episode but may also be used to maintain a lowered platelet count over a prolonged period in selected patients with primary thrombocythemia, in whom chemotherapy cannot be undertaken, and in symptomatic patients with secondary thrombocythemia.