Infectious Diseases

Question 1

Clostridium difficile

Answer 1

A: Antibiotics, old age, hospital stay.

S: Diarrhoea, abdominal pain, fever.

D: Increased WCC, x3 stool cultures, gram positive

T: Isolation, fluids, metronidazole, vancomycin

Question 2

Salmonella

Answer 2

A: Poultry, mammals, reptiles

S: Vomiting, diarrhoea, abdominal cramps

D: Blood cultures, stool cultures

T: Rehydration, ciprofloxacin (500-750mg BD)

Question 3

Shigella

Answer 3

A: Human only

S: headache, fever and abdominal pain then diarrhoea

D: Stool culture

T: Usually self limiting, antibiotics can reduce recovery time and severity

Question 4

Campylobacter infection

Answer 4

A: Campylobacter jejuni, the commonest cause of diarrhoea in the UK

S: Usually 24 hours later, headache, abdominal pain, nausea, vomiting diarrhoea and very high fever.

D: Stool culture x3

T: Mainly supportive with oral rehydration, IV fluids when needed. Antibiotics only if severe.

Question 5

Cholera

Answer 5

A: Vibrio cholera, spread by faecal contamination of drinking water.

S: Profound dehydration, reduced sodium, bicarbonate and bicarbonate, abrupt watery diarrhoea

T: Oral rehydration, IV fluids

Question 6

Tetanus

Answer 6

A: Clostridium tetani, rarely seen in developed countries

S: Start out restless and malaised. Then gets trismus and neck muscle spasms, followed by two months of other muscle spasms.

D: Clinical

T: Antitoxin (human tetanus IG), benzylpenicilllin IV, wound debridement

Question 7

Botulism

Answer 7

A: Improperly prepared food, contaminated heroin.

S: paralysis, nausea, diarrhoea, visual disturbance

D: Stool culture

T: IM antitoxin, benzylpenicilllin

Question 8

Gastroenteritis

Answer 8

A: Can be viral (rotavirus), E. Coli (raw veg and ground beef), vibrio cholera (seafood), c.diff, bacillus cereus (uncooked rice), salmonella (meat, eggs, poultry, milk) or protozoa

S: Diarrhoea, nausea, vomiting (especially in first 24 hours) dehydration, borborygmi (stomach gurgling), abdominal tenderness.

D: Increased WCC, stool cultures and microscopy

T: Oral rehydration solutions, IV fluids and monitor fluid balance

Question 9

Cytomegalovirus (CMV)

Answer 9

A: Shedding in secretions, crosses placenta to cause congenital infection.

S: Lymphadenopathy seen in 15% (where as EBV is 100%), usually asymptomatic, but fever, sweats and lethargy for a few weeks.

D: Deranged LFT’s, increased WCC, histology (owl-eye nuclei)

T: Antivirals if severe or in immune-compromised, otherwise supportive.

Question 10

Poliomyelitis

Answer 10

A: Poliovirus (an enterovirus) is transmitted faeco-orally,

S: Most are asymptomatic, but can present as aseptic meningits, with fever and flaccid paralysis.

D: Virus isolation from faeces, CSF, throat swab, antibody titre.

T: Bed rest, ventilatory support, physio

Question 11

Giardia intestinalis

Answer 11

A: Commonest intestinal parasite, worldwide distribution, but cysts can survive for long periods in water.

S: Asymptomatic carriage. Watery diarrhea, steatorrhoea, abdominal discomfort, bloating, weight loss, fatigue,, flatulence.

D: Stool sample for ova, cysts or parasites (OCP), hairy string test (swallow a string and pull it back up to see if the parasite has wrapped around it)

T: Tinidazole (2g five days apart) or metronidazole (400mg tds five days)

Question 12

Toxoplasmosis

Answer 12

A: Toxoplasma gondii, protozoan parasite found in cat faeces.

S: May be signs of old or active chorioretinitis on fundoscopy. Fever, lymphadenopathy, mild hepatitis.
Foetal infection: misscarriage, hydrocephalus

D: Serology: toxoplasma dye test, IgM antibodies, histology.

T: Supportive. Risk of blindness

Toxocariosis is similar but can be found in dog faces as well.

Question 13

Leishmaniasis

Answer 13

A: Protozoan infection transmitted in south america by sandflies

S: Fever, weight loss, hepatosplenomegaly, granulomatous lesion

D: Leucopenia, culture of lymph from lesion, bone marrow biopsy.

T: IV sodium stibogluconate, liposomal amphoterecin B

Question 14

Typhoid

Answer 14

A: faeco-oral transmission (via water) of salmonella typhi, salmonella paratyphi A, B and C.

S: Week 1: fever, headache, dry cough, abdomen pain
Week 2: High fever, delirium, rose spots (between nave and nipples), ‘pea-soup’ diarrhoea, bowel perforation, encephalitis.
3rd week: Death or slow recovery

D: Widal test, blood and stool culture,

T: Ciprofloxacin 750mg BD

Question 15

Diptheria

Answer 15

A: Corynebacterium diptheria spread from nose/throat of carrier.

S: Can have an insidious onset with listlessness, fever, tachycardia.
May have sore throat, nausea, vomiting and dysphagia, or can be painful ulceration with offensive smell.

D: Clinical (treat immediately) then confirmed by throat swab

T: Isolation, diptheria antitoxin, penicillin or erythromycin

Question 16

Lyme disease

Answer 16

A: Borrelia burgdorferi spirochaete, transmitted by ticks.

S: Early localised infection for 3-30 days, fever, headache, myalgia, arthralgia. Has neurological (meningitits, nerve palsies, neuritis, pain), cardiac (heart block, arrythmias), joint (arthralgia) manifestations.

D: Blood for antibodies to B. burgdorferi

T: Amoxicillin (500mg tds) and doxycycline (100mg BD).

Question 17

Leptospirosis (Weil’s disease)

Answer 17

A: Leptospira species, found in rat, dog and farm animals. Spread through contaminated water.

S: Fever, rigors, headache and photophobia (aseptic meningitis), conjunictival suffusion, myalgia, nausea, mild jaundice and mild renal impairment.

D: FBC (neutrophilia), ELISA serological test.

T: Supportive