Herpes Zoster Revised April 2007 HERPES ZOSTER Infection Control Guidelines for

Herpes Zoster Revised April 2007 HERPES ZOSTER Infection Control Guidelines for Long-Term Care Facilities Massachusetts Department of Public Health Division of Epidemiology and Immunization (617) 983-6800 Herpes zoster, or shingles, is a painful blistering rash caused by reactivation of varicella zoster virus (VZV), the causative agent in chickenpox. Shingles typically presents in one area on one side of the body, in the distribution of a nerve. There are usually no fever or other systemic symptoms. Pain and itching in the area of the shingles may persist after the lesions have resolved (post-herpetic neuralgia). Shingles can be treated with several antiviral agents. It can occasionally become serious in immune-compromised persons, with generalized skin eruptions and central nervous system, pulmonary, hepatic, and pancreatic involvement. Shingles is found worldwide and has no seasonal variation. The most striking feature of the epidemiology of shingles is the increase in incidence found with increasing age. Decreasing cell- mediated immunity (CMI) associated with aging is thought to be responsible for these increased rates. Similarly, the loss of CMI among persons with malignancies and HIV infection is thought to be responsible for higher rates of shingles among those populations. Approximately 20 percent of the general population will experience shingles during their lifetime and an estimated 500,000 episodes of shingles occur annually in the U.S. Approximately 4 percent of individuals will experience a second episode of shingles. A vaccine to prevent shingles in those who have already had chickenpox has recently been licensed for use in adults 60 years of age and older. It is contraindicated in persons with certain immune- compromising conditions. Infectious Agent: Varicella-zoster virus (VZV, chickenpox virus) Reservoir: Humans Mode of Transmission: VZV infection is transmitted to susceptible individuals (no history of chickenpox or varicella vaccine) by the following means: 1. From shingles cases: • direct contact with lesions 2. From disseminated shingles cases, or localized shingles cases in the immunocompromised: • airborne • direct contact with lesions Exposure to shingles can result in chickenpox in a susceptible person but cannot cause shingles. Exposure to chickenpox does not cause shingles. Incubation Period: Shingles has no incubation period; it is caused by reactivation of latent infection from primary chickenpox disease. Shingles is infectious until all lesions have crusted over. Infectiousness can be prolonged in immunocompromised patients. Herpes Zoster Page 2 of 11 Revised April 2007 Diagnosis: Clinical diagnosis. Laboratory confirmation is not usually indicated. However, isolation of VZV, or a positive Direct Fluorescence Antibody (DFA), Polymerase Chain Reaction (PCR), or Tzanck smear from a clinical specimen can be helpful. Treatment: Analgesics and antiviral drugs can be used to treat shingles. Control: Ensure that all healthcare workers are immune to chickenpox at time of employment. (See Attachment A, Revised Proof of Immunity.) For healthcare workers who have not been immunized or do not have serologic proof of immunity, careful screening for history of disease is important. Anyone with an uncertain history (regardless of age) should be not considered immune. In healthcare institutions, serologic screening of personnel who have a negative or uncertain history of chickenpox is likely to be reliable and cost-effective. Routine testing for chickenpox immunity after two doses of vaccine is not necessary because 99 percent of adults are seropositive after the second dose. Seroconversion, however, does not always result in full protection against disease. For vaccinated healthcare workers in long-term care facilities who are subsequently exposed to shingles (or chickenpox), most should be considered protected. However, the following measures may be considered if immunocompromised patients are present: • Test for serologic immunity immediately after exposure. (Latex Agglutination) LA can be done quickly and may be a useful post-exposure test. However, recent evidence has shown that false positive can occur, incorrectly categorizing a susceptible person as immune. Therefore, less sensitive EIAs are recommended for screening purposes when possible . • Retest 5-6 days after exposure to determine if an anamnestic response (boosting of antibody titres) is present. • Those workers who remain susceptible should be excluded. • Alternatively, consider exclusion or reassignment of personnel who do not have detectable antibody. 1. Prevent exposure to the case, as follows: Staff • Staff with localized shingles should cover lesions and should not care for high-risk patients until their skin lesions have become dry and crusted. • Staff with disseminated shingles and immunocompromised staff with shingles should be excluded for the duration of their illness. Patients • Patients with localized shingles should be cared for using standard precautions until all lesions are crusted: ƒ Only immune staff should care for these patients. ƒ Current or prospective roommates should be immune. ƒ Gloves should be worn when touching infectious material and during direct patient care. Clean gloves should be used before touching mucous membranes and nonintact skin. Herpes Zoster Page 3 of 11 Revised April 2007 Gloves should be changed between tasks and procedures on the same patient after contact with material that may contain a high concentration of virus. Gloves should be promptly removed after use and before touching noncontaminated items and environmental surfaces. ƒ Handwashing is necessary after touching the patient and before contact with another patient or with noncontaminated items and environmental surfaces, whether or not gloves were used. ƒ Masks, gowns, and eye protection should be worn during procedures and patient care activities likely to generate splashes of blood, bodily fluids, secretions, or excretions. ƒ Used patient care equipment and used linen should be handled in a manner that prevents skin and mucous membrane exposure and contamination of clothing. Patients with disseminated shingles and immunocompromised patients with shingles (either localized or disseminated) require standard, airborne, and contact precautions. In addition to the standard precautions listed above, the following precautions must also be followed: ƒ The room should have negative air-pressure ventilation. However, if this is not available, using a private room is acceptable. If a private room is unavailable, make sure roommates are immune and all visitors are screened for history of chickenpox or varicella vaccine. ƒ Gloves and gowns should be worn at all times. ƒ Susceptible staff or visitors should not enter patient room. If unavoidable, masks should be worn. Persons immune to varicella need not wear masks. 2. Identify all exposed individuals. • “Exposure” to uncomplicated shingles is defined as: contact with lesions; for example, through close patient care, touching, or hugging. • “Exposure” to disseminated shingles and localized or disseminated shingles in an immunocompromised person is defined as: 1) contact with lesions (for example, through close patient care, touching, or hugging); or 2) sharing indoor airspace with the infectious person (for example, occupying the same room). 3. Identify high-risk susceptible patients/staff among the exposed. Susceptible individuals are those without a reliable history of chickenpox or shingles, documentation of prior vaccination against chickenpox, or serologic proof of immunity. (See Attachment A, Revised Proof of Immunity.) High-risk susceptibles include those who are immunosuppressed due to underlying medical conditions (including HIV infection), treatment or medications (including steroids), or who are susceptible pregnant women. They are at greater risk for complications from varicella and should be referred promptly to their health care provider. These high-risk susceptibles should receive VZIG (varicella zoster immune globulin) as soon as possible within 96 hours of exposure. Please note, bone marrow transplant recipients should be considered susceptible regardless of past history of disease. 4. Identify and vaccinate other exposed susceptibles. Susceptible individuals are those without a reliable history of chickenpox or shingles, documentation of prior vaccination against chickenpox, or serologic proof of immunity. (See Attachment A, Revised Proof of Immunity.) If the varicella vaccine is given within 3 (and possibly up to 5) days of exposure to VZV, it can prevent disease. If 5 days have passed since exposure to the case, the vaccine should still be Herpes Zoster Page 4 of 11 Revised April 2007 given, as it will protect against possible future exposures. Chickenpox can still occur in susceptible contacts in spite of vaccination, but vaccinating someone who is incubating chickenpox or who is immune is not harmful. See attachments B and C, “Special Considerations in the Administration of Varicella Vaccine”, and “Suggested Intervals Between Administration of Immunoglobulin Preparations and Measles-Containing and Varicella Vaccines”, respectively, for information about groups who should not receive varicella vaccine. 5. Discharge or isolate exposed susceptible patients. Isolate on contact and airborne precautions all exposed, susceptible patients who cannot be discharged from before day 10 after exposure, from day 10 through day 21 after exposure. Those who have received VZIG must remain in isolation until day 28. 6. Conduct surveillance for chickenpox for 21 days (one incubation period) after the last exposure to shingles. For those who received VZIG and where immunocompromised individuals are involved, surveillance should continue for 28 days. REFERENCES American Academy of Pediatrics. Red Book 2006: Report of the Committee on Infectious Diseases, 27th Edition. Illinois, Academy of Pediatrics, 2006: 711-725. Heymann, DL. Ed. Chickenpox-herpes zoster. Control of Communicable Diseases in Man. 18th ed., American Public Health Association, Washington, DC, 2004: 94-100. Centers for Disease Control and Prevention. Advisory Committee on uploads/Sante/ herpes-guide.pdf

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