The varicella-zoster virus (VZV) causes two diseases: varicella (chicken pox) and herpes zoster (shingles). Chicken pox is a common childhood disease. For the approximately 1% to 10% of adults who are susceptible to VZV (1,2,3,4,5,6 and 7), exposure poses a significant risk of infection.

Assessment of Healthcare Workers’ Immune Status A common goal of all infection control programs is to protect patients from healthcare workers who may be incubating infectious diseases after exposure in the community or in the hospital. All employees should, on their postoffer employee screening, be asked about a history of chicken pox. A healthcare worker with a positive history of chicken pox can be considered immune (5,6,7,8,9,10,11,12,13,14,15,16,17,18 and 19). If the healthcare worker denies having had the disease or has an uncertain history for chicken pox, a serologic test, if deemed costeffective by the institution, may be done to determine his or her immune status (see also Chapter 76).

Institutions should develop guidelines for managing healthcare personnel eligible for the varicella vaccine (20). If the healthcare worker is not immune (either by history or serologic test), the varicella vaccine should be offered (16,17,18,19 and 20). Serologic testing for postvaccination antibodies is not required (16,17,18 and 19). Personnel who develop a rash after receiving the varicella vaccine must avoid contact with persons without evidence of immunity who are at risk for severe disease and complications until all lesions resolve (i.e., are crusted over or fade away) and no new lesions appear within a 24-hour period (15,21).

Nonimmune healthcare workers for whom the vaccine is contraindicated should be educated about the risk they pose to patients, should they be exposed to VZV and become infected. They should not be assigned to the care of any patient with chicken pox or herpes zoster.

Exposures to Varicella-Zoster Virus After a case of chicken pox has been confirmed in a patient or healthcare worker, infection preventionists should compile a list of personnel and patients exposed to the index case. The names of exposed employees are provided to the employee health service so that the immune status of those exposed can be determined. Exposed healthcare workers who are not immune should be furloughed. The period of contagiousness of infected persons is estimated to begin 1 to 2 days before the onset of the rash and to end when all lesions are crusted (18). Thus, furlough should begin 8 days after the first day of exposure and extend through day 21 after the last day of exposure (6,7,14,15,18,20,21).

It is very important that nonimmune employees report chicken pox exposures whether they occur in the community or in the hospital. Employers should furlough healthcare workers with pay for exposures that occur within the institution. Without this policy, employees are reluctant to report their exposures. Although employees are strongly encouraged to report community exposures, few institutions furlough employees with pay after exposures in the community.

Although the risk of infection with VZV is less after exposure to a patient with herpes zoster than after exposure to a patient with chicken pox, the clinical manifestations
of chicken pox are the same after acquisition of infection by either type of exposure (12). Nonimmune healthcare workers who have direct physical contact with draining vesicles of patients with herpes zoster should also be considered exposed and furloughed from work (12). Nonimmune healthcare workers should refrain from working with patients with herpes zoster (12).

Often, the source of exposure to VZV is a healthcare worker. One of the most important functions for the employee health service during the investigation of a VZV exposure episode is to confirm VZV infection in the index case. Once VZV infection has been confirmed, the employee must be furloughed until all lesions are crusted (12). Although the furlough may be instituted by either the infection control department or the employee health service, the employee must return to the employee health service to be cleared before returning to work.

Prophylaxis using varicella-zoster immune globulin should be considered for nonimmune exposed healthcare workers who are at high risk for complications of varicellazoster infection (pregnant and immunosuppressed employees) (22,23) (see also Chapters 43, 75, and 76).

The American Thoracic Society issued a statement in 1967 recommending that all hospitals have a “consistent program of tuberculin testing … of all employees who may be subject to exposure” (24). By 1983, the Centers for Disease Control and Prevention (CDC) recognized that all healthcare workers were not at equal risk for acquiring tuberculosis (TB) and recommended skin testing based on individual classification of risk for a facility and the location and prevalence of untreated TB in the community, in the institution, and among personnel (25,26).

Because of these recommendations, many hospitals in the late 1980s discontinued or restricted their purified protein derivative (PPD) skin testing program. However, since 1988, there has been a dramatic increase in TB in the United States that is largely related to the human immunodeficiency virus (HIV) epidemic (26,27 and 28). Hospitals have had to reassess their TB surveillance plans and develop mandatory skin testing policies for healthcare workers. These programs should include baseline TB skin tests upon employment, periodic retesting for at-risk employees, postexposure evaluation, preventive therapy as indicated, and employee education (26,29) (see also Chapter 38).

Healthcare workers with a positive TB skin test on initial testing or with a skin test conversion after exposure should be evaluated for active TB by the employee health service. Persons with symptoms suggestive of TB should be evaluated regardless of skin test results. If TB is diagnosed, appropriate therapy should be instituted. Healthcare workers with a reactive skin test but without disease should be educated about the signs and symptoms of disease and instructed to report immediately to the employee health service for evaluation, should they develop any of these signs and symptoms.

Healthcare workers who have active pulmonary or laryngeal TB, endobronchial or tracheal disease, or a draining TB skin lesion pose a risk to patients and staff. Therefore, the CDC recommends that the healthcare worker be excluded from work until adequate treatment has been instituted, cough has resolved, and sputum has been found free of acid-fast bacilli on smears from three consecutive specimens collected at 8- to 24-hour intervals with at least one sample from an early morning specimen (because respiratory secretions pool overnight) (29).

Healthcare workers who cannot take or do not accept or complete a full course of preventive therapy should be counseled about the risk of reactivation of infection and development of disease and should be instructed to seek evaluation promptly if symptoms develop that may be due to TB.

Annual and postexposure tuberculin skin test results should be monitored routinely. Results of skin tests should be placed in the healthcare worker’s medical records and recorded in an aggregate form for analysis of skin test conversion patterns in various areas of the hospital. The aggregate data set should include information about each skin test conversion such as job classification, work location, date of first PPD, and date of positive PPD. Analysis of the aggregate data set is done by the infection control department to determine whether personnel in any area or service in the hospital have an increased incidence of skin test conversions. An increased incidence of skin test conversions in a given area or service may indicate that the infection control procedures to prevent transmission of TB in that area or service need to be improved.

Since 1984, the recommendations of the Advisory Committee on Immunization Practices (ACIP) for immunization against influenza have included healthcare workers as a group because they may transmit influenza to patients (30). The annual recommendations for adults were published in the 2008 ACIP guidelines. Annual vaccination against influenza is recommended for any adult who wants to reduce the risk for becoming ill with influenza or of transmitting it to others. Vaccination is also recommended for all adults in the following groups because these persons are either at high risk for influenza complications or are close contacts of persons at higher risk: