Gastroenteritis Viruses (Dentistry)

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Gastroenteritis Viruses (Dentistry)

• Prof. Dr. Asem Shehabi
• Faculty of Medicine
• University of Jordan

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Enteroviruses-1

• Enteroviruses group family Picornaviruses, 71
  Serotypes Includes Polioviruses,
  Coxsackieviruses, Echoviruses Hepatitis A
  virus.
• Virus structure SSve 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 gt
  Tep. 60C..Widely distribution in Humans, Animals
  Feces.. Contaminate Water, Fresh Food.
• Sporadic epidemic infection..Highly
  communicable.. Mostly through fecal-oral
  transmission.

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Poliovirus-Rota virusIcosahedral symmetry
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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

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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

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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..

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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.

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Flaccid Paralysis
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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.
  

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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.

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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.

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

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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 lt 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

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Noroviruses Other Caliciviruses

• Noroviruses Part of Calicivirus group.. SSve
  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.

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• 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.