Background for Development of Guidelines
Guidelines for Primate Facilities
Guidelines for Medical Evaluation and Treatment
Notice of Publication of 1990 Guidelines by Holmes et
al.
B Virus as a Laboratory Hazard
Background for Development of Guidelines
The guidelines were developed by the B Virus Working Group in January, 1990.
The B Virus Working Group consisted of 44 specialists invited by the Robert W. Woodruff Health Sciences Center of Emory University and the CDC.
The guidelines were published as "Guidelines for the Prevention and Treatment of B-Virus Infections in Exposed Persons" in Clinical Infectious Diseases (1995; 20:421-439) by the following authors: Gary P. Holmes, Louisa E. Chapman, John A. Stewart, Stephen E. Straus, Julia K. Hilliard, David S. Davenport, and the B Virus Working Group. (See the Notice to Readers, an MMWR document that summarizes the guidelines.)
A call to Dr. Louisa Chapman at CDC in December, 1996 confirmed that these guidelines are the ones currently recommended by CDC.
The previous CDC guidelines were published in October, 1987 as "Guidelines for Prevention of Herpesvirus Simiae (B Virus) Infection in Monkey Handlers" (MMWR 36(41);680-682,687-689).
Guidelines for Primate Facilities
"All macaques should be presumed to be shedding B virus and should be handled accordingly."
"The most critical period for the prevention of B-virus infection is the first few minutes after an exposure."
"The evaluation of exposures will be easier if all employees who may have contact with macaques or with their body fluids or tissues have serum specimens collected before the start of employment and annually during employment."
"The diseases in question include hepatitis B, tetanus, rabies, and bacterial infections as well as B-virus infections."
"HSV may enter host cells within 5 minutes of exposure, and it is likely that B virus does so as well."
"If the eyes, mouth, nose, or other mucosal surfaces have been exposed, irrigate the site for at least 15 minutes with sterile saline solution or rapidly flowing water only (never with hypochlorite). For injuries at other sites, any concentrated solution of soap or detergent, povidone-iodine, or chlorhexidine may be used."
". . . the time spent in scrubbing or soaking the wound (15-20 minutes) is more important than the type of solution used. Gentle massage of deep wounds can increase contact with the cleansing solution."
Diagnostic Testing Options
"In summary, if the results are interpreted cautiously, serological testing of specimens from persons with definite exposures or possible symptoms is helpful in the confirmation and management of human B-virus infection."
"Screening of asymptomatic persons in the absence of a specific, clear exposure is rarely indicated and should be undertaken only with an awareness of the harm that could follow the misinterpretation of false-positive results."
The medical evaluation of exposed workers is concerned with:
(1) the immediate phase--from exposure until results of initial cultures (usually in 7 days) or until onset of symptoms (usually between 5 and 30 days)
"The most common pathogens involved in both animal and human bite wounds (Staphylococcus aureus, anaerobic cocci, and Bacteroides species) are well covered by a combination of amoxicillin and clavulanic acid."
". . . the risk assessment (based on the nature of both the exposure and the injury, the adequacy of first-aid measures , and the clinical status of the involved monkey) can be applied to the delineation of an immediate management strategy, a process that includes an assessment of the desirability of antiviral prophylaxis."
"The decision to initiate antiviral therapy should not be made lightly."
"It is the consensus of the working group that the treatment of an asymptomatic person with oral or intravenous acyclovir while awaiting laboratory results is of unproven benefit, may complicate diagnostic issues by suppressing seroconversion, is unnecessary after most macaque-related injuries, and cannot be recommended in most situations."
"Clear evidence of viral shedding by the monkey may merit a consideration of empirical antiviral therapy for persons sustaining high-risk injuries, particularly if the injured site has been inadequately cleansed."
"Through close follow-up of persons who have had high-risk exposures and who are not receiving empirical acyclovir therapy, the development of symptoms or laboratory evidence of B-virus infection may be detected during the first 4 weeks. It is a reasonable precaution to advise individuals who have had high-risk exposures to avoid activities involving the exchange of body fluids, including saliva, throughout the potential incubation period of B-virus infection."
(2) the secondary phase--from onset of symptoms or positive results of cultures or serology until symptoms resolved or shedding of B virus ceased;
"If B virus is isolated from initial post-cleansing specimens or from specimens obtained from the monkey, the development of suggestive signs or symptoms (table 1) warrants immediate hospitalization for evaluation, isolation, and empirical treatment."
"The drug of choice for empirical antiviral therapy for B-virus infection is acyclovir;"
". . . the recommended oral dosage for presumptive therapy would be similar to that used against varicella-zoster virus: ~ 800 mg five times per day for at least 14 days."
". . . some experts recommend hospitalization for intravenous therapy (10 mg/kg every 8 hours ) to ensure that blood levels are maintained at ~ 20 ug/mL for at least 2 or 3 days before a switch to oral therapy is considered."
(3) the long-term phase--from end of secondary phase until indefinitely;
