What is the recommended treatment and management for a patient suspected of having herpes B, particularly those with occupational exposure to macaques?

Herpes B Virus: Treatment and Management

Immediate Treatment Protocol

For any suspected herpes B virus exposure in individuals with occupational contact with macaques, initiate intravenous acyclovir 10-15 mg/kg every 8 hours immediately, as this is a biosafety level 4 pathogen with high mortality from fatal encephalomyelitis if untreated. 1, 2

Understanding Herpes B Virus

Herpes B virus (Herpesvirus simiae) is common in macaque colonies but causes devastating disease in humans:

• Transmission occurs primarily through monkey bites, scratches, contact with saliva, tissues, or tissue fluids 1, 3
• Fatal encephalitis is the typical outcome in untreated human infections 1, 3
• The virus produces only mild localized lesions in its natural macaque host but severe neurological disease in humans 1
• One case of person-to-person transmission has been documented 1
• Airborne transmission is postulated in two cases, though evidence is weak 1

Clinical Presentation and Diagnosis

High-Risk Exposures Requiring Treatment

• Animal handlers and laboratory workers with macaque exposure 1, 3
• Any bite, scratch, or mucous membrane exposure to macaque saliva or bodily fluids 1, 3
• Dermatologists may be involved in initial evaluation of exposed animal handlers 3

Diagnostic Challenges

• The virus can remain latent in sensory ganglia, leading to missed diagnoses 2
• Extensive antigen cross-reactivity with HSV, SA8, and HVP-2 causes frequent false-positive results 2
• Timely diagnosis with sensitive and specific methods is critical but challenging 2

Treatment Algorithm

First-Line Therapy: Intravenous Acyclovir

Initiate IV acyclovir 10-15 mg/kg every 8 hours immediately upon suspicion of herpes B exposure or infection:

• Do not wait for laboratory confirmation before starting treatment 4
• Continue treatment for minimum 14-21 days or until clinical resolution 4
• The remarkable safety and efficacy of acyclovir justify empiric treatment given the life-threatening nature of herpes B encephalitis 4

Monitoring During Treatment

• Monitor renal function closely with dose adjustments for renal impairment 4
• Ensure adequate hydration to prevent acyclovir-induced nephrotoxicity 4
• CSF analysis with PCR testing has high sensitivity and specificity for herpesvirus detection 4

Management of Acyclovir Allergy

If severe allergic reaction develops during treatment:

• Discontinue acyclovir and treat allergic symptoms with methylprednisolone 5
• Apply intravenous acyclovir desensitization protocol, as this is the only effective treatment option for herpes B encephalitis 5
• Desensitization has been successfully performed in life-threatening herpesvirus infections with no alternative treatment 5

Critical Pitfalls to Avoid

• Never delay acyclovir treatment while awaiting diagnostic confirmation - the high mortality rate of untreated herpes B encephalitis mandates immediate empiric therapy 1, 2, 4
• Do not rely on serologic testing alone - cross-reactivity with other herpesviruses causes false positives 2
• Do not use oral acyclovir - severe CNS disease requires intravenous administration at high doses 4
• Do not discontinue treatment prematurely - herpes B can establish latency in ganglia, requiring extended treatment courses 2

Occupational Health Implications

• All personnel working with macaques must be educated about herpes B transmission risk 1
• Immediate wound care and medical evaluation are essential after any macaque exposure 1, 3
• Prophylactic treatment should be considered for high-risk exposures even without symptoms 1

Current Treatment Limitations

• No effective vaccines or specific drugs beyond acyclovir are currently available 2
• Slow progress in understanding viral invasion and life cycle has hindered drug development 2
• Establishment of specific pathogen-free (SPF) monkey colonies remains a research priority 2