Herpes infection

200204022 송지근

http://pathmicro.med.sc.edu/virol/herpes.htm

Herpes Virus 소개• Very large virus · Genome encodes at least 80 proteins

• From greek – means “to creep”• Family(Subfamily) · Herpesviridae(Alphaherpesvirinae)

• Genus · Simplexvirus

• Species · HHV-1, HHV-2

• Envelope · glycoprotein 존재 , fragile• Tegument · contain virally-encoded protein and enzyme• Capsid : Icosahedral Capsid · doughnut shape (diameter : 100-200nm) · icosahedral capsid (162 capsomeres)• Genome : ds DNA Genome · Double stranded DNA

Morphology

Viral Enzyme

• DNA-dependent DNA polymerase• Thymidine kinase · dNTP 생성

• Ribonucleotide reductase · convert ribonucleotides to deoxynucleotides

• Serine-protease · convert a scaffoding protein to its final form

• Glycoprotein

HSV replication

• Binding• Fusion• Protein synthesis · early genes 만 발현시 Latency · early and late protein → lytic replication

• DNA synthesis• Assembly• Release of virus

Lytic or Latency

Herpes Simplex Virus(HSV)• HSV-1, HSV-2 · very similar characterstic · cell of mucoephithelia, enter through wounded · persistently infect macrophage and lymphocyte• HSV-1 · above the waist · oral mucosa, trigeminal ganglia • HSV-2 · below the waist · genital mucosa, sacral ganglia

Transmission• Direct contact : infected lesion or secretion · anyone who comes in contact with fluid containing infecious

virus is at risk

• HSV-1 · Mouth to mouth (kissing or use of utensils conta-minated wit

h saliva) · Hand, through the eyes

• HSV-2· Normally spread sexully· Genital area : anus, rectum, urethra, penis, vulva etc

HSV-2 and pregnancy

• 보통은 출산시 감염• Infect in utero → fatal, rare · Underdeveloped immune system → spread to many peri

pheral organ, infect central nervous system · 임신중 처음 감염시 태아로 전염될 확률이 높다

• 출산시 virus 가 활동중이면 제왕절개 시행

Immune response

• Neutralization of infectious virus : IgM, IgA, IgG

• Complement-mediated lysis of infected cells : IgM, IgG

• Interferon, CTL, lymphocyte, NK cell

HSV 가 병을 일으키는 부위

Disease caused by HSV

Oral herpes• HSV-1 or HSV-2 infection• Lips → All parts of mouth, pharynx• Reactivation : trigeminal ganglia → cold sores• Herpes pharyngitis : other viral infection 과 연관• Severe in Immunosuppressed people

Herpes keratitis• Eye infection (HSV-1)• Recurrent, blindness

Herpes whitlow• HSV-1, HSV-2• Small wound

on the hand or wrist

• Healthy care worker

Herpes gladiatorum• Wrestlers• Head and neck lesion• More often on the right side of the body• Rugby : Herpes Rugbeiorum (scrum pox)

Eczema herpeticum• Preexisting atopic dermatitis• Eczema lesion → spread over the skin• Liver, adrenal• Similar disease : eczema vaccinatum

Genital herpes 90% : HSV-2, 10% : HSV-1 Primary infection• Asymptomatic or many painful lesion on urogenital organ• Transient viremia, Fever, Myalgia, Inguinal adenitis Secondary episodes(reactivation)• Sacral ganglion• Less severe than the first episode• burning sensation → eruption• Without overt symptom → 전염 가능

HSV proctitis• Inflamation of rectum, anus

HSV meningitis• HSV-2 infection• Syptom seem to resolve spontaneously

HSV encephalitis• HSV-1 infection, fatal• Sporadic viral encephalitis• Damage to temporal lobes• Blood in the spinal fluid• Neurological symptom : seizures

Diagnosis

• Tzank smear, Histochemistry · formation of syncytia · cowdry type A inclusion body in nucleous

• Specific Ab in an immunofluorescence test · HSV-1 : gG1, HSV-2 : gG2

• In situ hybridization

HSV chemotherapy

Interferon 연고Nucleoside analog durgs• Acyclovir, Famcivlovir, Valacyclovir• Viral DNA polymerase 억제• Ineffective against latent virus• Resistant type : lack of thymidine kinase

Prevention

• Incureable• Avoid infection → Healthy care worker 에 중요• Latex comdom• 증상이 나타날 때 접촉을 피한다• HSV-2 : prodromal itching symptom or active lesion