5- GI viruses & parasites

Question 1

what are the important gastroenteritis viruses?

Answer 1

• norovirus (also called winter vomiting)
• rotavirus
• hep B

Question 2

what is treatment for gastroenteritis viruses (most of them)?

Answer 2

supportive treatment - rehydration via oral route

Question 3

what is norovirus? (what is transmission, what is length of symptoms, some facts etc)

Answer 3

• very contagious = survives the cold & heart
• spreads via faecal oral route - food, drink , environment = cruise ships perfect place to spread

need to hand wash!! (no hand gel)

• 48 hours symptoms, starts within 12-24 hours after exposure
• winter virus

Question 4

what is rotavirus? (what is transmission, what is length of symptoms, some facts etc)

Answer 4

• dehydrated very quickly so was deadly for children but now vaccine given before 15 months = very effective vaccine
• faecal oral transmission
• affects children in winter & spring - less severe in adults unless older than 65 or immunosuppressed
• symptoms start 2-3 days from contact and last for up to 1 week

Question 5

what are important symptoms of hepatitis?

Answer 5

• fatigue!
• discoloured urine & stool
• lethargy
• nausea
• itchy skin

Question 6

what are potential complications from hepatitis?

Answer 6

• cirrhosis
• cryoglobulinemia
• fibrosis
• hepatic encephalopathy
• liver cancer
• liver failure
• portal hypertension

Question 7

what is treatment of hepatitis?

Answer 7

depends but may be antiviral drug and fluid & rest

Question 8

what is epstein barr virus? (what is transmission, what is length of symptoms, some facts etc)

Answer 8

= also called infectious mononucleosis - kissing disease

• 90% people infected by adulthood, infects B lymphocytes
• transmits in saliva & other body fluid
• not really any treatment

symptoms = flu like illness with big spleen & big liver (fever, sore throat, lymphadenopathy, hepatitis, rash, fatigue)

usually between 2-4 weeks but fatigue especially can go on & on

Question 9

what is an important differential of epstein barr virus?

Answer 9

HIV = has very similar/same symptoms so will have to test for HIV if suspected epstein barr virus

Question 10

what body area does epstein barr virus affect?

Answer 10

lots of places - meningitis, encephalitis, facial nerve palsies, psychosis
- has a role in cancer too

Question 11

does IgM or IgG form first?

Answer 11

IgM

Question 12

what is acute cytomegalovirus infection? (what are symptoms, some facts etc)

Answer 12

• symptoms = fever, fatigue, sore throat, swollen lymph glands (fatigue for less time than EBV)
• bad to get when pregnant →effects baby = small head, small cranium, learning difficulties, large liver or spleen, hearing or eye problems

Question 13

what happens with immunosuppressed if have cytomegalovirus infection?

Answer 13

in very immunosuppressed people →get colitis when reactivate CMV e.g. if get HIV (CD4+ count low then very immunosuppressed and at risk for CMV colitis etc if higher than less at risk)

• get different symptoms

Question 14

what is best diagnostic tests for cytomegalovirus infection?

Answer 14

biopsy

Question 15

what are some summary important points about hep A? (transmission, treatment, some facts)

Answer 15

faecal oral, often after travel, is vaccine which recommended if more at risk like travel, immunosuppressed etc →people who immune will have positive IgG and people who have it now positive IgM, no treatment →acute liver inflammation, doesn’t give chronic disease

Question 16

what are some summary important points about hep B? (transmission, treatment, some facts)

Answer 16

transmitted by blood or bodily fluids, is vaccine, can be screened for (if donating blood etc), is a treatment, most people asymptomatic but gives you chronic disease

Question 17

what is transmission of hep C?

Answer 17

inject drugs people get if sharing needles - transmitted by blood

Question 18

what is transmission, treatment and significant fact about hep D?

Answer 18

need to have B to get D, treated by vaccinating hep B, transmitted by blood contact

Question 19

what is transmission of hep E?

Answer 19

faecal oral

Question 20

what does positive Hep B surface antigen (HBsAg)?

Answer 20

HBsAg = protein on surface of virus →positive means virus present (it stimulates antibody production)

Question 21

what does positive anti surface antibody (anti-HBs) mean?

Answer 21

either recovered or have immunity (from vaccine or naturally had infection and recovered)

Question 22

what does positive hep B core (anti HBc) mean?

Answer 22

• produced in response to virus
• indicates past or current infection (positive for life) (don’t get from vaccine)

Question 23

what does positive hep B core IgM (IgM anti-HBc) mean?

Answer 23

means in acute phase of infection = when pick up

• 70% will have persistent infection, 40% asymptomatic. disappears after acute infection

Question 24

what test is done for parasite test?

Answer 24

stool test - test for oocysts & parasites

Question 25

what is cryptosporidium? (what is transmission & symptoms)

Answer 25

• typically found outside in rivers & waterways - particularly ones in contact with animals
• oocysts can infect you
• nutritional deficiencies, weight loss and dehydration

Question 26

what is giardia lamblia? (what is transmission & symptoms)

Answer 26

• swim in pools, lakes & rivers - untreated water & sanitation (often abroad)
• flagellates protozoa
• explosive, intermittent, large volume foul swelling diarrhoea →malabsorption

Question 27

what is entamoeba histolytica? (what is transmission, testing & symptoms)

Answer 27

• causes amoebiasis
• causes liver cysts - can present years after travel
• do multiple microscopy tests as only 60% positive
• PCR good