To determine whether hepatitis B virus (HBV) transmission occurred among patients visiting a physician's office and to evaluate potential transmission mechanisms.

Serologic survey, retrospective cohort study, and observation of infection control practices.

Private medical office.

Those visiting the office between March 1 and December 26, 2001.

We identified 38 patients with acute HBV infection occurring between February 2000 and February 2002. The cohort study, limited to the 10 months before outbreak detection, included 91 patients with serologic test results and available charts representing 18 case-patients and 73 susceptible patients. Overall, 67 patients (74%) received at least one injection during the observation period. Case-patients received a median of 14 injections (range, 2-25) versus 2 injections (range, 0-17) for susceptible patients (P < .001). Acute infections occurred among 18 (27%) of 67 who received at least one injection versus none of 24 who received no injections (RR, 13.6; CI95, 2.4-undefined). Risk of infection increased 5.2-fold (CI95, 0.6-47.3) for those with 3 to 6 injections and 20.0-fold (CI95, 2.8-143.5) for those with more than 6 injections. Typically, injections consisted of doses of atropine, dexamethasone, vitamin B12, or a combination of these mixed in one syringe. HBV DNA genetic sequences of 24 patients with acute infection and 4 patients with chronic infection were identical in the 1,500-bp region examined. Medical staff were seronegative for HBV infection markers. The same surface was used for storing multidose vials, preparing injections, and dismantling used injection equipment.

Administration of unnecessary injections combined with failure to separate clean from contaminated areas and follow safe injection practices likely resulted in patient-to-patient HBV transmission in a private physician's office.

To identify modes of HCV transmission during an outbreak of HCV infection in a hemodialysis unit.

An epidemiologic study, virologie analysis, assessment of infection control practices and procedures, and technical examination of products and dialysis machines.

A private hemodialysis unit treating approximately 70 patients.

Detection of HCV RNA by PCR was performed among patients receiving dialysis in 2001. Case-patients were patients who had a first positive result for HCV RNA between January 2001 and January 2002 and either acute hepatitis, a seroconversion for HCV antibodies, or a previous negative result. Three control-patients were randomly selected per case-patient.

Of the 61 patients treated in the unit in 2001 and not infected with HCV, 22 (36.1%) became case-patients with onset from May 2001 to January 2002 for an incidence density rate of 70 per 100 patient-years. Phylogenic analysis identified four distinct HCV groups and an index case-patient for each with a similar virus among patients already known to be infected. No multidose medication vials or material was shared between patients. Connection to a dialysis machine by a nurse who had connected an HCV-infected patient “just before” or “one patient before” increased the risk of HCV infection, whereas using the same dialysis machine after a patient infected with HCV did not. Understating, lack of training, and breaches in infection control were documented. Direct observation of practices revealed frequent flooding of blood into the double filter on the arterial pressure tubing set.

During this outbreak, HCV transmission was mainly patient to patient via healthcare workers' hands. However, transmission via dialysis machines because of possible contamination of internal components could not be excluded.

To describe an outbreak of hepatitis C virus (HCV).

Retrospective cohort study.

Outpatient department of a hospital in Rome, Italy.

All 42 patients exposed to ozone therapy by autohemotherapy or intramuscular injection from January to June 2001.

Epidemiologic investigation, serologic analysis, and virus genotyping.

Thirty-one (74%) of the patients agreed to participate in the study. Three (9.7%) had symptoms of HCV infection. This incidence rate was higher than the rate of 1.4 per 100,000 per year in the regional population. Six patients were positive for HCV antibodies and HCV RNA for a prevalence rate of 19.4%, which was much higher than the estimate of 0.9% in the population. Virus genotype lb was found in two case-patients (one symptomatic) and 2c in four case-patients (two symptomatic), one of whom was known to have an HCV infection since 1986 and could have been the source of infection. The infected patients were all being exposed to ozone-enriched transfusions of autologous blood. Although the specific mode of transmission between patients was not detected, transmission probably occurred during one of the three busiest therapeutic sessions in the 6-month period.

Transmission of HCV infection may occur during medical procedures with limited bleeding. Standard precautions must be applied in any healthcare setting; restricting the number of individuals treated during each therapeutic session could be an effective way of avoiding accidental transmission of infection.

To describe the usefulness of the OraQuick Rapid HIV-1 Antibody Test (OraSure Technologies, Bethlehem, PA) in cases of occupational exposure regarding its use with source-patient sera, effects on post-exposure prophylaxis (PEP) use, potential cost savings, and effects on healthcare worker (HCW) stress reaction symptoms.

Before-and-after analysis.

A 269-bed, tertiary-care medical center with adjacent clinics.

All source-patients and HCWs experiencing an occupational exposure during the study period.

Use of the OraQuick test with patient sera was validated prior to its use for occupational exposures. Exposures from January 1 through July 10, 2003 (enzyme immunoassay [EIA] group) and July 11 through December 31, 2003 (OraQuick group) were retrospectively reviewed and the use and cost of PEP was compared for each group. Randomly selected HCWs from both groups completed a survey to assess their stress reaction symptoms.

After exclusion, there were 71 exposures in the EIA group and 79 in the OraQuick group. OraQuick results were 100% concordant with the reference standard of EIA and Western blot using patient sera. The mean number of doses ingested per course of PEP was significantly higher for HCWs in the EIA group (3.8; range, 0 to 6) compared with the OraQuick group (1.2; range, 0 to 3; P = .016). Cost analysis revealed a mean savings of $6.62 with the OraQuick test per occupational exposure. Although the survey failed to detect an overall reduction in HCW stress reaction symptoms using OraQuick for source-patient testing, 11 HCWs in the EIA group had repetitive thoughts of the exposure compared with 5 in the OraQuick group (P= .049).

Because of the reduction in ingested doses of unnecessary PEP and reduced cost of occupational exposure management with their use, rapid HJV-antibody tests should be the preferred method for source-patient testing following an occupational exposure.

To characterize accepted workers' compensation claims for needlestick injuries filed by healthcare workers (HCWs) in non-hospital compared with hospital settings in Washington State.

Descriptive study of all accepted workers' compensation claims filed between 1996 and 2000 for needlestick injuries.

All Washington State HCWs eligible to file a state fund workers' compensation claim and those who filed a workers' compensation claim for a needlestick injury.

There were 3,303 accepted state fund HCW needlestick injury claims. The incidence of needlestick injury claims per 10,000 full-time-equivalent HCWs in hospitals was 158.6; in dental offices, 104.7; in physicians' offices, 87.0; and in skilled nursing facilities, 80.8. The most common mechanisms of needlestick injury by work location were as follows: for hospitals, suturing and other surgical procedures (16.7%), administering an injection (12.7%), and drawing blood (10%); for dentists' offices, recapping (21.3%) and cleaning trays and instruments (18.2%); for physicians' offices, disposal (22.2%) and administering an injection (10.2%); and for skilled nursing facilities, disposal (23.7%) and administering an injection (14.9%). Nurses accounted for the largest (29%) proportion of HCWs involved, followed by dental assistants (17%) and laboratory technicians and phlebotomists (12%) in non-hospital settings. Rates of needlestick injury claims increased for non-hospital settings by 7.5% annually (95% confidence interval [CI95], 4.89% to 10.22%; P < .0001). Rates decreased for hospital settings by 5.8% annually, but the decline was not statistically significant (CI95, -12.50% to 1.34%; P < .1088). HCWs were exposed to hepatitis B, hepatitis C, and human immunodeficiency viruses in non-hospital settings.

There was a difference in the incidence rate and mechanisms of needlestick injuries on review of workers' compensation claim records for HCWs in non-hospital and hospital settings.

To determine human immunodeficiency virus (HIV) type 1 genotypic antiretroviral drug resistance profiles of patients presenting a risk or potential risk for occupational exposure of healthcare workers.

Observational survey involving HIV-infected patients. Blood samples collected from source-patients and potential source-patients underwent HIV-1 genotypic antiretroviral resistance testing and determination of CD4 counts and viral load. Affected healthcare workers were monitored for 6 months after exposure.

The survey was conducted in a tertiary-care hospital located in Sao Paulo, Brazil. Sao Paulo is considered the epicenter of the HIV-acquired immunodeficiency (AIDS) virus epidemic in Brazil.

Source-patients, potential source-patients, and affected healthcare workers.

A total of 371 occupational exposures to biological materials were reported, 46 (12.3%) of which were from HIV-seropositive source-patients. Samples from 18 source-patients and 26 patients considered “potential sources for accidents” were analyzed. Of these 44 samples, 18 (41%) presented resistance-related mutations in reverse transcriptase, protease, or both. Of these 18 samples, 16 (89%) had resistance to drugs included in the prophylactic schedule recommended by the Brazilian Ministry of Health.

Use of the Centers for Disease Control and Prevention-Brazilian post-exposure prophylaxis regimen will result in the administration of antiretroviral agents to which the source HIV-1 isolate will often be resistant. Therefore, it would be advisable to carefully investigate the history of use of antiretroviral agents by source-patients and adjust the prophylactic therapy based on those data and, subsequently, the results of resistance testing.