Gastroenteritis Viruses (Dentistry) Prof. Dr. Asem Shehabi Faculty of Medicine University of Jordan

Enteroviruses-1 Enteroviruses group: family Picornaviruses, 71 Serotypes: Includes: Polioviruses, Coxsackieviruses, Echoviruses & Hepatitis A virus. Virus structure: SS+ve RNA, Rigid Capsule consist of 4-different polypeptides (VP1-4), Responsible for Attachment, virus replication in cytoplasm & release new virus. Pathogenesis: Attached to mucosa Respiratory or direct Small Intestines cells.. Replication in RT-lymph nodes & Peryes’ pathes.. Spread within 1-3 weeks to blood & less to CNS. General Characteristics: Survive for weeks/months at room Temp. & longer in cold water, fresh vegetation, Stable pH 3-9, Killed rapidly at > Tep. 60C..Widely distribution in Humans, Animals Feces.. Contaminate Water, Fresh Food. Sporadic & epidemic infection..Highly communicable.. Mostly through fecal-oral transmission.

Poliovirus-Rota virus Icosahedral symmetry

Human Enteroviruses-2 Infections more common in developing countries..refuge camps with Low standard of hygiene, lack of clean water supply.. frequently in Summer . Most infections cause mild-asymptomatic enteritis.. watery diarrhea & fever.. Rarely severe/ Chronic Gastroenteritis/CNS diseases Other Clinical Features: mild Pharyngitis, Skin rashes, Acute hemorrhagic conjunctivitis, Pneumonia..CNS disorder.. Aseptic meningo-encephalitis, Mild paralysis, Hand-foot-mouth disease.. Mostly infected children.. less adults.. Most infections self-Limited. General immunity: Humoral & mucosal lifelong Immunity to specific virus serotype.. Rare re-infection with same serotype..Generally mild symptoms healthy persons

Poliomeylitis-1 Poliovirses: Only human reservoir, 3 Serotypes, each with a slightly different capsid proteins antigens.. 50% RNA homology with other enteric viruses.. All 3 types cause the same disease symptoms..Type-1 associated more with Paralytic disease. Epidemic outbreaks may include 2 to 3 types.. mostly cause mild human poliomeylitis in children. All Polioviruses survive long in cold water & moist environment for Few weeks/months.. Relatively resistant to antiseptic/ disinfection agents compared to other enteric viruses.. Poliovirus Infection:, Oral-Fecal Route..Multiplies first oropharynx, Spread to local lymph nodes.. Second multiplication in the gut mucosa.. mesenteric lymph nodes.. Later virus spread to Blood & CNS.. Incubation 3-21 Days

Poliomeylitis-2 During acute /subclinical Infection period.. Virus is shed in large number in feces..infect close contacts.. Mostly children under 5-year.. Spread by contaminate water, fresh food & hands Three Clinical Features: 1-Asymptomatc Poliomeylitis: 99% young children, Mild clinical symptoms/ Influenza-Like.. often associated with mild fever & gastrointestinal symptoms for few days..infection confirmed only by laboratory test. 2-Abortive Poliomeylitis: 0.5-1% infected children develop minor non-specific illness.. Mild diarrhea, headache, sore throat, fever, Mild CNS symptoms like back pain, aseptic meningitis. Both clinical forms resulted in rapid recovery within one week with developing long-live immunity..

Poliomeylitis-3 3-Paralytic Poliomeylitis: less 1% cases cause Aseptic meningitis.. 1/1000 Children.. 1/75 Adults.. Associated muscle weakness.. legs are affected more often than the arms The limb becomes floppy and weak.. A condition known as Acute Flaccid Paralysis.. due to destruction Lower motor neurons.. Inflammation the Gray matter of spinal cord..may be associated with invasive & damage brain stem cells causing Bulbar Poliomeylitis .. This sever form very rare.. Virus damage brain and spinal neurons.. Painful muscle spasms.. Respiratory paralysis.. High mortality. Polio maternal infection acquired late in pregnancy.. May cause mild Poliomyelitis Natural Infection & following Polio-vaccination .. Specific IgA, IgG.. Permanent Long-live Immunity.

Flaccid Paralysis

Poliomeylitis-4 2-Types Poliovaccines : Inactivated Salk Poliovaccine (1956) Given Intramuscularly.. stable at room temperature.. still used in USA & Few countries. Poliovaccine Sabin (1962): Oral attenuated life virus.. Inactivated by room & high Tep.. Vaccine should kept at refrigeration temp ..More used Worldwide.. Jordan Both Contain 3 types Polioviruses: 4-Doses divided (1,2,4,6 Months) in association with Triple Vaccine .. Children should be free of Fever, Diarrhea before given the vaccine.. Otherwise immune response will not develop enough immunity.

Coxsakieviruses Coxsakieviruses: Both groups common in human feces, contaminated water fresh food.. Both groups cause invasion mucosa of respiratory & intestinal.. causing mild sore throat/ diarrhea or both..Rarely spread to Blood, CNS.. Common Aseptic meningitis in infants & skin rash.. Epidemic outbreak 90% asymptomatic mild infection..develop immunity. Coxsakieviruses Group A infections: 26 serotypes 1-Acute Hemorrhagic Conjunctivitis: highly contagious disease.. painful & swelling of eyelids.. Conjunctive Bleeding.. All ages 2-Herpangina: Mild to severe sore throat.. associated with painful small vesicular or ulcerative lesions on oral mucosa, soft palate, Persist few days-2 weeks.

2/ Similar to Herpes simplex virus infection.. Mostly children.. Less other ages. 3-Hand-Foot-Mouth Disease: Fine macular skin rashes, Palm & Soles.. may spread to arms and legs fever.. Both mouth & skin ulceration .. Continue for 1-2 weeks, mostly children. 4-Hemolytic Uremic Syndrome (HUS): caused by certain serotypes of Coxsackie A and B Following RT infection & Viremia.. Rarely cause kidney damage or flaccid paralysis. Coxsackie Group B: 6 serotypes .. infect the heart, pleura, pancreas, liver, causing febrile illness, myocarditis, pericarditis , hepatitis mostly in infants & immunosuppressed patients. No Vaccine or Antiviral treatment, Interferon may help.

Coxsakieviruses Oral Ulcerations are common many times each year in persons of all ages without underling conditions

Echoviruses Echoviruses (Enteric Cytopathgenic Human Orphan): 30 serotypes .... Generally less virulent & infectious than Coxsakieviruses. Common cause of acute febrile illness in infants and young children..Poor hygiene Clincal disease: Asymptomatic or mild Respiratory Infection mostly associated with contaminated fresh food & water.. May acquired in swimming pool. Rare cases: Acute aseptic meningitis, Encephalitis , Hemorrhagic hepatitis, Myocarditis & Pericarditis , Hemolytic Uremic Syndrome mostly Children.. More severe diseases observed in newborn babies (neonatal infection) who have no maternal antibodies..higly fatal. Specific immunity develop against few serotypes.. No specific antiviral treatment or vaccines.

Rotavirus Double-S RNA virus/Family Reoviridae. Common Type A & C found in intestines human, animals, Birds. Rotavirus  causes gastroenteritis. Symptoms include: Mild- severe diarrhea, vomiting, fever, and dehydration. Almost all children are likely to be infected before their first month birthday. Rotavirus causes more acute severe diarrhea in Infant-Children aged < 2 Years..Rarely older children & adults. Common in Winter.. Incub.2-4 Days.. Accounted for 20-50% of all diarrhea in infants.. High incidence with low standard of hygiene, hospitals & nurseries outbreaks. Chronic diarrhea common in malnourished infants.. Difficult to control..High Infant Death in developing countries Immunity: Recently introduced vaccine..Specific intestinal IgA Antibodies.. Protective ( 80-90%). Lab. Diagnosis: Feces examination by Rapid Rota-Latex Test. Treatment: No specific drugs, Fluid Rehydration most important

Noroviruses & Other Caliciviruses Noroviruses: Part of Calicivirus group.. SS+ve RNA, non-enveloped .. Widely distributed in polluted water with human and animal feces.. especially cattle, pigs, cats, chicken.. highly infectious pathogens .. Personal contact,  food poisoning infections worldwide Acute gastroenteritis / Enteritis in humans.. More in young children than adults.. Inflammation stomach & small- large intestines.. Approximately 50% of all gastroenteritis outbreaks in developed countries are caused by Norovirus.. infant & children more susceptible than adults..diarrhea may last few days..Treatment oral dehydration..No antimicrobial drugs. Caliciviruses are similar in morphology, structure & epidemiology to norovirus.

2/ Caliciviruses infection: Gastroenteritis or only watery diarrhea accompanied by abdominal cramps.. Some people also complain of headache, fever/chills, and muscle pains.. Symptoms usually last for 1-2 days. Astroviruses.. SS-Ve RNA, small, round viruses with a characteristic star-like appearance in the electron microscope. Found in intestines human & animal alone or with Rota & other enteric viruses. Mostly causing Acute/mild diarrhea infant & young children.. Occasional outbreaks in schools, nurseries, camps, families all ages.. associated with cold food, fishes, Ice creams, cold water All Enteroviruses infections develop specific intestinal antibodies & partial immunity ..Rarely reinfection within few months..No vaccine.. Supportive treatment.