Pg 8 - Pg 10 Flashcards
(1) DNA virus, enveloped, large size
(2) Cause latent and sometimes recurring diseases
Herpes viruses
causes fever blisters, cold sores, gingivostomatitis, keratoconjunctivitis (e.g. neonate, contact lens wearer), genital lesions, meningitis (neonate)
Herpes simplex (types 1 2)
(1) Primary lesion generally more severe
than subsequent lesions
(2) Viruses hide (go latent) in nerve ganglia serving region of the primary lesion
(3) Lesions recur periodically – usually in response to some type of stress stimulus (excess UV light at beach, onset of menstrual period, emotional stress of death or illness of loved one)
(4) Virus held in check primarily by cell-mediated immunity although antibodies exist.
Herpes simplex (types 1 2)
Primary lesion is more severe than subsequent. Then the virus goes latent in the ____. Typically held at bay by ____ but can recur periodically, often due to stress (e.g., emotional stress, menstruation, UV light)
Nerve ganglia
cell-mediated immunity
(5) No adequate vaccine is available.
(6) Treat with medication to relieve symptoms, but not to cure/eradicate virus
Herpes simplex (types 1 2)
Herpes a DNA or RNA virus?
Enveloped or nah?
DNA
Enveloped
Mother may pass herpes virus onto vaginally delivered neonates, causing?
keratoconjunctivitis
meningitis
causes chicken pox and shingles (latent/recurring)
Herpes zoster (HZV) (formerly named Varicella-Zoster)
(a) Acquired via respiratory tract
(b) Causes vessicle-type skin lesions - moderately large, relatively few, mostly on trunk of body
(c) Viruses may hide in nerve ganglia
(d) Viruses held in check by CMI
chicken pox (herpes zoster)
(a) HZV re-emerges from hiding in nerve ganglia
(b) Cause numerous, small, closely- spaced vessicles in area served by the infected nerve ganglion (e.g. across shoulder, under arm from breast to shoulder blade, across thigh)
(c) Virus outbreak subsides after few-to several weeks, but may recur periodically
(d) Virus held in check by cell-mediated immunity
shingles (herpes zoster)
(1) Transmitted by oral secretions (saliva)
(2) Infects B-cell
(3) Causes infectious mononucleosis in adolescents and adults
(a) Fever, sore throat, enlarged lymph nodes, fatigue, swelling of liver or spleen
(4) Virus may be eliminated by Cell Mediated Immunity or go into latency
(5) Latent viruses may reactivated (switch to lytic cycle) upon B-cell stimulation, e.g. by an unrelated infection
Epstein-Barr virus (EBV)
(3) Causes infectious mononucleosis in adolescents and adults
(a) Fever, sore throat, enlarged lymph nodes, fatigue, swelling of liver or spleen
Epstein-Barr virus (EBV)
(4) Virus may be eliminated by Cell Mediated Immunity or go into latency
(5) Latent viruses may reactivated (switch to lytic cycle) upon B-cell stimulation, e.g. by an unrelated infection
(6) May be associated with chronic diseases (unknown, uncertain)
Epstein-Barr virus (EBV)
Epstein-Barr transmitted how?
oral secretions
Infectious mononucleosis (Epstein-Barr) ssx?
Fever, sore throat, enlarged lymph nodes, fatigue, swelling of liver or spleen
Causes congenital cytomegalic inclusion disease in children
and
Latent virus infection in immunosuppressed / immunocompromised organ transplant, malignancy, AIDS
Cytomegalovirus (CMV)
(a) Baby is infected from vaginal microbiota during birthing
(b) Occasionally causes CMV mononucleosis with microcephaly, jaundice, multiple organ involvement
(c) Impairment of central nervous system is associated with development of mental/physical retardation. Rarely causes obvious illness.
congenital cytomegalic inclusion disease
Cytomegalovirus (CMV)
(a) Febrile mononucleosis
(b) Multiple organ involvement (pneumonitis, hepatitis, GI ulcerations, encephalopathy)
(c) Severity of disease related to competency of cell-mediated immunity
Cytomegalovirus (CMV)
a. RNA virus; 8 species (A-H)
b. The most common cause of severe epidemic diarrhea in infants & young children (Rotavirus A accounts for 90% of infections) – Vaccine (2006)
Rotavirus
Which type of Rotavirus account for 90% oof infections (i.e., diarrhea)
Rotavirus Type A
Rotavirus transmitted how?
Fecal-oral transmission
RNA virus, non-enveloped – Norwalk virus is the only species of the genus Norovirus, and “Norwalk virus” is the preferred nomenclature.
Norwalk virus (Norovirus) [and Sapovirus and Astrovirus]
can present like a bacterial diarrheal agent
major worldwide cause of epidemic and sporatic viral gastroenteritis - causes ~90 % of epidemic nonbacterial gastroenteritis (schools, families, camps, etc.)
(1) 18-48 hours incubation, causes vomiting, diarrhea, cramps, and low-grade fever
(2) Illness lasts 12-60 hours and often remits spontaneously
Norwalk virus (Norovirus) [and Sapovirus and Astrovirus]
“Epidemic” and sporatic viral gastroenteritis…
schools, camps, etc.
Norwalk virus (Norovirus) [and Sapovirus and Astrovirus]
d. Transmitted by food, water, vomitus – very difficult to prevent spread
Norwalk virus (Norovirus) [and Sapovirus and Astrovirus]
