Herpesvirus Infections

LUTHERAN MEDICAL CENTER

Dental Residency Program

Literature Review Form

Resident: Adam J. Bottrill Date: 17JUL09 Region: St. Joseph’s

Article title: HERPESVIRUS INFECTIONS

Author(s): Greenberg, Martin S. DDS

Journal: Infectious Diseases and Dentistry

Volume #; Number; Page #s): Vol. 40; Number 2, pp. 359-367

Year: 1996

Major topic: Herpesvirus

Minor topic(s): NA

Type of Article: Topical Review

Main Purpose: Review various presentations and treatments of multiple forms of the herpesvirus.

Overview of method of research: Literature review and summary.

Findings: N/A

Key points in the article discussion:

A. All 7 herpesviruses have the following common characteristics.

1. Four Layers (DNA, capsid, tegument, lipid envelope)

2. Primary infection followed by latent period.

3. Recurrent infections (symptomatic or asymptomatic)

4. Transmitted through direct contact with saliva or genital secretions.

5. Shed in the saliva of asymptomatic hosts.

6. Known to transform cells in tissue culture.

B. Herpes Simplex Virus: Two major herpes simplex viruses are HSV 1 and HSV2. HSV1 is MOSTLY transmitted via saliva and associated with “upper body” infections. HSV2 is MOSTLY transmitted via genital secretions and associated with anal/genital infections. Rate of HSV1 infection goes up after 6 mo. And peaks between 2 and 3 y.o. HSV2 infection rate increases after sexual activity begins.

1. Primary: Frequently subclinical or are difficult to distinguish from URI’s. Can be preceded by fever, chills, malaise, nasea and lymphadenopathy. Oral manifestations include vesicles and ulcers of oral mucosa.

2. Reactivation: Stimulated by trauma, fever menstruation etc. Recurrences appear most commonly on the lips but can be present on the hard palate and gingiva.

3. Dx: Typically diagnosed clinically but may be done via lab tests. SHOULD ALWAYS BE RULED OUT WRT THE IMMUNOCMPROMISED (IC) PT.

C. Cytomegalovirus: Frequent cause of asymptomatic infection in humans. Clinically significant cases are rare except in neonates and IC Pt’s. Xmitted via genital secretions, breast milk, saliva and blood. CMV can cause potentially fatal congenital infection cytelomegalic inclusion disease. Infant CMV almost always involves enlarged salivary glands. In adults, can cause a mono-like disease with clinical manifestations including hepatitis, pneumonitis, lymphadenopathy, splenomegaly and myocarditis. At-risk individuals include organ transplant, HIV and IC pts. Oral lesions in AIDS pts have been described as slowly enlargening ulcers.

1. Dx: Histologic evaluation and culture of suspected lesions (owl eye cells) or viral culture. Culture can take up to 1 month but is most diagnostic.

D. Varicella-Zoster Virus:

1. Primary: Chicken pox (varicella) is usually a benign illness of children spread by direct contact with lesions or nasopharyngeal secretions. Lesions are typically pruritic macules and papules that become vesicles with erythematous halo.. 10-20 day incubation and pts are infectious for about 1 week after symptoms begin. Adults have 15x higher mortality rate due to increased incidence of encephalitis. Other symptoms include pneumonitis and Reye’s syndrome (progressive encephalopathy).

2. Recurrent: Shingles (herpes zoster) occurs when the latent virus (dorsal root nerve ganglia) becomes reactivated. Typically occurs at C-3, T-5, L-1, L-2. When trigeminal nerve involved, usually involves ophthalmic. Symptoms initially include pain, tenderness and parasthesia. This is followed by unilateral vesicles forming along the course of the affected nerve (Ramsay-Hunt syndrome). 15-20% of trigeminal infections involve 2nd and 3rd division leading to possible intra-oral lesions. Can be life-threatening to IC pts. Course of the zoster can be shortened with large doses of acyclovir. Additional sequela of herpes zoster may take the form of postherpetic neuralgia.

3. Dx: Typically made via characteristic clinical signs and proper medical history. When atypical cases present, tissue culture and viral isolation can confirm.

E. Epstein-Barr Virus: Affinity for B lymphocytes. Virus is spread by infected saliva or blood.

1. Primary: Typically subclinical or mild in children. Young adults present with infectious mononucleosis. Symptoms of “mono” include fever, malaise, pharyngitis, lymphadenopathy and possible splenomegally. Most pts recover within a month.

2. Dx: Based on clinical signs and bloodwork (detection of activated T-lymphcytes and heterophil antibodies).

3. Important note: EBV is associated with: Hairy leukoplakia, Burkitt’s lymphoma, nasopharyngeal carcinoma and possibly B cell lymphoma.

F. Human Herpes Virus 6: Discovered in 1986, has a strong affiliation for CD4 lymphocytes. Causes roseola (common disease among children) which presents with fever and a rash. Suspected the HHV6 is related to mono, pneumonia, meningitis and encephalitis.

G. Human Herpes Virus 7: Most recently discovered herpesvirus detected on CD4 lymphocytes. Distinguishable from HHV-6 by DNA analysis. Can initially infect in the 2nd yr of life (later than HHV-6). Transmitted via saliva.

Summary of conclusions: There are more than 80 known viruses of the herpes group. This article presents brief summaries of seven of them

Assessment of article: Though not an experimental research-based article, it did provide concise summaries of the seven aforementioned herpesviruses. One area not covered was effective treatment methods. It is possible that there may be a more recent summary article with more updated information on this.