Tuberculin skin test conversion rates in New York City Emergency Medical Service health care workers

Tuberculin skin test conversion and reactivity rates among adults with and without human immunodeficiency virus in urban settings in Ethiopia

To investigate whether low CD4+ T-cell counts in healthy and human immunodeficiency virus (HIV)-infected Ethiopians influence tuberculosis (TB) immunological memory, tuberculin skin test (TST) conversion and reactivity rates were investigated among adults with and without HIV infection in urban settings in Ethiopia. Reaction to the TST was analyzed with purified protein derivative by the Mantoux technique. A total of 1,286 individuals with TST results of > or = 5-mm (n = 851) and < or = 4-mm (n = 435) induration diameters were included. Individuals with < or = 4-mm induration sizes were followed up for 21.4 +/- 9.5 months (mean +/- standard deviation) to observe skin test conversion. The overall TST reactivity (> or = 5-mm induration diameter) was 66.2% (n = 851). Reactivity was significantly lower among HIV-positive persons (40.5%) than among HIV-negative persons (68.7%) (P < 0.001). Of the above persons, 32 incident TB patients were checked for their TST status 13.05 +/- 11.1 months before diagnosis and reactivity was found among 22 (68.7%) of them. Of the TST-negative persons with 0- to 4-mm indurations who were followed up for 3 years, the conversion rate to positivity was 17.9/100 person-years of observation (PYO) (14.4/100 PYO and 18.3/100 PYO in HIV-positive and -negative persons, respectively). Despite lower absolute CD4+ T-cell numbers in Ethiopians, higher TST conversion and reactivity rates show the presence of a higher rate of latent TB infection and/or transmission. The lower TST positivity rate before a diagnosis of TB disease showed the lower sensitivity of the test. This indicates the need for other sensitive and specific diagnostic and screening methods to detect TB infection, particularly among HIV-positive persons, so that they can be given prophylactic isoniazid therapy.

Emergency medical services utilization during an outbreak of severe acute respiratory syndrome (SARS) and the incidence of SARS-associated coronavirus infection among emergency medical technicians

Objectives: This was a study to evaluate the utilization of emergency medical services (EMS) systems during the outbreak of severe acute respiratory syndrome (SARS), and to assess the incidence of infection among emergency medical technicians (EMTs). Methods:This was a prospective, observational study conducted in the EMS system of Taipei, Taiwan. Probable/suspect cases of SARS were defined by World Health Organization criteria. SARS‐related transports were categorized into 1) requests from hospitals for probable/suspect cases of SARS, 2) quarantined individuals, and 3) febrile persons. City ambulances were organized into teams A, B, and C for transports of different perceived risks. Data on the EMS volume, the transport category, the final SARS status of patients, and the EMT responsible for the transports were collected. The EMS projected volume was computed by previous years' data and compared with that collected. The SARS incidence among EMTs was assessed by investigating probable SARS (P‐SARS) and by surveying the seroprevalence of SARS‐associated coronavirus (SARS‐CoV) antibody. Results: From March 18 to June 19, 2003, there were 7,961 EMS transports, similar to the volume projected from previous years (7,506) (95% CI = 6,688 to 8,324). Of these, 1,760 (22.1%) were SARS‐related. When SARS‐related transports were excluded, there was a 12.2% decrease (95% CI = 11.4% to 12.9%) in EMS activities. Requests from hospitals, quarantined individuals, and febrile citizens accounted for 23%, 18%, and 59% of SARS‐related transports. Among the 397 P‐SARS cases in the city of 2.65 million people (incidence 0.01%, 95% CI = 0.01% to 0.02%), 138 (35%) required EMS transports. Two EMTs working in team C, the team with the lowest risk, developed P‐SARS. One of them died soon thereafter. The incidence of P‐SARS was 0.6% (95% CI = 0.2% to 2.2%), or 0.1% (95% CI = 0.03% to 0.4%) per transport. SARS‐CoV serology was available in 74.1% of EMTs who were alive. In addition to the surviving P‐SARS EMT, one EMT from team A, the team with the highest risk, was seropositive. Combining P‐SARS and the seropositive case, three EMTs were infected (incidence 1.3%, 95% CI = 0.4% to 3.6%). No patient transported by the infected EMTs developed SARS. The hospitals serving EMS by the infected EMTs had been involved in a clustered outbreak prior to the EMTs' infections. Conclusions: During the outbreak of SARS, the overall EMS volume did not change significantly, but the non‐SARS EMS activities decreased. Compared with the general population, EMS providers are at higher risk of contracting the SARS virus regardless of different perceived levels of risk. Standard protections and procedures for infection control should be strictly followed during transport and within the hospital environment.

Paramedics can apply and read Mantoux tuberculosis tests

Selected paramedics (26) received 2 h of training in the application and interpretation of Mantoux skin tests by a specially trained registered nurse. Instruction included a lecture, a video tape, and practice skin test administration on "induration arms." All students successfully completed written and skills tests. During a follow-up period, registered nurses directly observed skin test application and interpretation by the paramedics when applying the skin test to other departmental fire fighters and compared these to set criteria. Interpretation of skin test results included appropriate referral for positive results. Paramedics administered 319 skin tests during subsequent follow-up and 305/319 (96%) were monitored by a registered nurse. All administration criteria were performed as indicated 100% of the time except for the criterion requiring a 5-10 mm wheal. The application was appropriately repeated in each case. In one application, a paramedic began to use the same needle and syringe to draw up additional solution, but was immediately corrected. Among 227 cases of test interpretation by paramedics, paramedics were monitored by a registered nurse in 169 interpretations (74%). All monitoring criteria were performed as indicated 100% of the time. Nurses concurred with each monitored measurement. Induration results were 0 mm, 216 tests; 1-9 mm, 9 tests; > or =10 mm, 2 tests. Appropriate follow-up was provided to the two individuals with > or =10 mm induration. The results indicate that paramedics can successfully apply and accurately interpret Mantoux skin tests on public safety employees, although the number of positive tests was low, reducing the reliability of the findings.

The occupational hazards of emergency physicians

Emergency physicians are exposed to a variety of occupational hazards. Among these are infectious diseases, such the human immunodeficiency virus, hepatitis B and C viruses, and tuberculosis. Hepatitis G virus is transmissible but may not be a cause of illness. The likelihood of being exposed to these agents appears to be higher in the ED than other medical settings but estimates of the prevalence of these diseases in the ED vary, depending on the patient population served. Estimates of risk for contracting these infections are reviewed. Measures to prevent these exposures can reduce risk, but compliance is low, particularly for those involving changes in the behavior of emergency physicians (such as not recapping needles). Latex allergy is a hazard of health care workers. Its prevalence is reported to be quite high, but these findings are difficult to interpret in the absence of a universally accepted definition of the condition. Its prevalence in emergency physicians is not known. Other noninfectious hazards include workplace violence and exposure to nitrous oxide. The health effects of rotating shift work may put emergency physicians at increased risk of coronary artery disease and impaired reproductive health. Emotional stress is another hazard of emergency physicians, and may lead to burnout.