NIOSH Issues Report about Herpes B Exposure
Cercopithecine herpesvirus 1 (Herpes B) is common in monkeys but rare in humans. A case two years ago in which a 22-year-old researcher at Yerkes primate center was infected with Herpes B by a rhesus macaques monkey made headlines and forced many research and academic facilities to rethink how they handle personal protection for employees and students. The National Institute for Occupational Safety and Health (NIOSH) has issued a report about preventing exposure to Herpes B.
On Oct. 29, 1997, the researcher was assisting with a routine group capture of rhesus macaques monkeys in a free-ranging corral. Personnel conducting the capture wore uniforms, disposable latex gloves, and surgical masks. Eye protection was not worn. During the transfer of a macaque into a squeeze cage, some type of body fluid from the monkey splashed into the researcher's eye. She wiped her eye when it happened, and approximately 45 minutes later flushed her eye with tap water for 23 minutes. There was no medical treatment or consultation at the time of the exposure.
On Nov. 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, which are characteristic of ocular herpes infections. Although dendritic corneal lesions were reported in a previous fatal Herpes 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 Herpes B virus infection was unlikely.
The researcher subsequently developed a Cercopithecine herpesvirus 1 (Herpes B virus) infection. Despite intensive antiviral therapy, she died on Dec. 10, 1997. This incident is the first documented case of a Herpes B virus infection resulting from an ocular exposure to macaque secretions.
According to NIOSH, preventing worker exposure to biohazardous material is the best protection against infection. Employers should ensure that worker protection programs, policies, and procedures are in place to control infection risks from NHPs. Employers should conduct training and periodic assessments to ensure that worker protection programs are effective. In particular, all employees who come into contact with macaques or macaque tissues should be trained about the risks of Herpes B virus and other infections, and the importance of preventive measures.
NIOSH also recommends that 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; addresses training, inspection, and maintenance; and requires periodic assessment of program effectiveness. Mandatory PPE should be selected based on a thorough work site hazard assessment that considers all work procedures and associated hazards (including biohazards), potential routes of exposure, and potential adverse health outcomes.
If workers are exposed to biohazards, then decontamination procedures are critical to minimizing the risk of infection. Animal handlers should be instructed to immediately and thoroughly cleanse all bites, scratches, or mucosal surfaces or abraded skin exposed to biohazards, and to report these exposures immediately. Following an eye exposure, existing guidelines recommend immediately flushing the eye for at least 15 minutes. Existing guidelines should also be followed for cleansing bites, scratches, or other wounds.
Second, post-exposure 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 Herpes 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. When possible, a veterinarian should assess the clinical and virologic status of the source animal.
Information about Herpes B virus and preventive measures can be obtained from NIOSH at 1-800-35-NIOSH or from the NIOSH Homepage at http://www.cdc.gov/niosh. Other sources of information include the B Virus Research and Resource Laboratory, Georgia State University, P.O. Box 4118, Atlanta, GA 30302-4118; 404-651-0808 and the Centers for Disease Control and Prevention, 1600 Clifton Road, Atlanta, GA 30333; 404-639-2888. (Callers should indicate the need for additional information about Herpes B virus.)