HID 5
On November 8, 1997, the researcher sought medical attention for the first time because the exposed eye was red and swollen. At this time, the emergency department physician specifically looked for dendritic lesions of the cornea that are characteristic of ocular herpes infections. Although dendritic corneal lesions were reported in a previous fatal B virus infection, they were not seen in the present case. On the basis of the reported circumstances of the contact, it was initially concluded that B virus infection was unlikely. This case is reported in the following:
There have been approximately 40 known cases of fatal human B virus infection described in the English language literature. Previously reported human infections usually have been attributed to macaque bites or scratches, injuries from needles used near a macaques mucous membranes or central nervous system, or contact with infectious products from the macaques. Incubation periods may be as short as 2 days, but more commonly they are 2 to 5 weeks. Most documented infections have occurred among biomedical research employees who worked with macaques. Laboratory workers handling only infected central nervous system or primary monkey kidney cell lines have also been exposed and, in at least one instance, infected. One case of person-to-person transmission has been reported.
Holmes GP, et al. [1995]. Guidelines for the Prevention and Treatment of B-Virus Infections in Exposed Persons. Clinical Infectious Diseases 20:421439.
ANSI [1989]. Practice for Occupational and Educational Eye and Face Protection, Z87.11989. American Society of Safety Engineers, Des Plaines, IL.
Each institution working with NHPs should develop a written, comprehensive personal protective equipment (PPE) program that clearly identifies the PPE required for each specific task or working area of the facility and addresses training, inspection and maintenance, and periodic assessment of program effectiveness. Mandatory PPE should be selected based on a thorough worksite hazard assessment that considers all work procedures and associated hazards (including biohazards), potential routes of exposure, and potential adverse health outcomes. Reviews of injuries and biohazard exposures among workers exposed to NHPs suggest that mucocutaneous contact with NHP body fluids is common; in one survey, 16 of 17 contacts with primate body fluids involved ocular exposure. Although the 1987 Centers for Disease Control and Prevention (CDC) Guidelines for the Prevention of Herpesvirus simiae (B virus) Infection in Monkey Handlers discourages handling fully awake macaques, macaque handlers should be protected with appropriate eye protection when it is necessary to remove physically active animals from cages. The incident described in this report indicates that proper eye protection should also be mandatory during activities such as entering areas containing macaques, conducting captures, and transporting caged macaques. Other activities that require eye protection should be determined by the hazard assessment. Appropriate protective eyewear selection should be based on a number of factors, including the nature and extent of the hazard, nature of the work, associated degree of risk, and requirements of the individual user. Protective eyewear should meet or exceed the criteria established by ANSI. Eye protection must be comfortable, accommodate the need for corrective lenses (eyeglasses), and be adjustable to ensure a secure fit. It may be necessary to provide several different types, styles, and sizes. Personal eyeglasses are not PPE.
Protective goggles designed for splash protection (available with antifog lenses for humid environments and in models that preserve peripheral vision) should be worn to protect the eyes against splash hazards in combination with a mask designed to protect other mucous membranes. Faceshields are commonly considered secondary eye protectors that are worn in combination with protective goggles. Although previous guidelines for the prevention of B virus indicate that faceshields may be sufficient, ocular exposures have occurred to workers wearing faceshields. In one incident, an animal technician was splashed in the eye with an unknown fluid while wearing a combination surgical mask/faceshield during the transfer of a monkey within cages. The "faceshield" worn during this exposure, a surgical mask with attached plastic eye shield, did not provide adequate protection. To minimize the potential for mucous membrane exposure, faceshields must prevent droplet splashes to the head from running down into the eyes and prevent mucous membrane exposure around the edges (sides, top, and bottom to below the chin). Decisions to use faceshields as the sole means for preventing ocular exposure should be made only after full consideration of both the limitations of faceshields and Occupational Safety and Health Administration (OSHA) regulations.
If exposure prevention fails, the adequacy and timeliness of wound or exposure decontamination procedures are critical factors determining the risk of infection. Institutions that house or conduct procedures involving macaques or potentially contaminated tissues should develop institution-specific postexposure procedures. Such procedures will ensure appropriate diagnostic testing and infection control. First, animal handlers should be instructed to immediately and thoroughly cleanse all bites, scratches, and/or mucosal surfaces or abraded skin exposed to macaque biologic materials and to report these exposures immediately. Following an eye exposure, existing guidelines recommend immediately flushing the eye for at least 15minutes. Existing guidelines should also be followed for cleansing bites, scratches, or other wounds. Second, postexposure procedures should provide potentially exposed workers with direct and rapid access to local physicians knowledgeable about the infectious risks of exposure to NHPs, hazards of B virus infection, signs and symptoms, and treatment, as well as other biohazards associated with NHPs. These physicians should be available on an on-call basis in the event of an exposure. The employer should ensure that direct access to the knowledgeable consultant is available immediately following exposures and at any time the worker is concerned that potential occupational exposure to B virus may be relevant to worker symptoms. When possible, a veterinarian should assess the clinical and virologic status of the source animal. Postexposure procedures should also include routing diagnostic specimens to the B Virus Research and Resource Laboratory (at Georgia State University in Atlanta).
Medical personnel who evaluate primate handlers with conjunctivitis after an eye exposure to potentially infectious material should be aware that the absence of dendritic lesions of the cornea, like the absence of herpetic skin vesicles, does not reliably rule out B virus infection.
These recommendations will be reviewed and may be revised or augmented following additional consideration by a working group to be convened by the CDC Office of Health and Safety.
B Virus Research and Resource Laboratory, Georgia State University, P.O. Box 4118, Atlanta, GA 303024118; 404-651-0808
Centers for Disease Control and Prevention, 1600 Clifton Road, Atlanta, GA 30333; 404-639-2888 (Callers should indicate the need for additional information about B virus.)
May 1999 DHHS (NIOSH) Publication No. 99-100