Febrile returned traveller Flashcards Preview

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Flashcards in Febrile returned traveller Deck (11):
1

History key points of travelled patient

Where have you been and what did you do?- Organism exposure
When were you there and when did you start to get sick- timeline fit with incubation

2

Infections with clinical features and incubation:
Influenza; TB; salmonella typhi and enteritidis; campylobacter jejuni; hep A; malaria; dengue;HIV; syphilis

- resp, few days; air
- resp, many months; air
- non specific and diarrhoea, days; water + food
- diarrhoea, days; water + food
- jaundice, weeks; water + food
- non specific, weeks; vectors
- muscle aches, days; vectors (aedes mosquito)
- non specific, weeks to months; people
- variable, weeks to months; people

3

Malaria causing organisms

Protozoa, inside anophles mosquito vector

Common: plasmodium falciparum (potentially fatal) and vivax (pretty benign)
Rare: Ovale and malariae

4

Places with anophles mosquitos and thus higher risk of acquiring malaria

PNG, Solomons an Vanuatu
None in New caledonia, Fiji, Samoa, Tonga etc

5

Plasmodium pathogenesis

-Infected ____ mosquito feeds on blood, and injects ___, containing _____ (infects new host)
-______ invade ____ cells and replicate (10 days)
-______ (from liver cell replication) are released from liver and invade _____
-Replicate in ______ and rupture them, ___, rigors, sweats
-Reinfects blood cells
-Some _____ mature into male or/and? female gametocytes which are source of sexual replication in mosquito salivary gland

body can keep under control and have low levels of circulating protozoa

-Infected female mosquito feeds on blood, and injects saliva, containing sporozoites (infects new host)
-Sporozoites invade liver cells and replicate (10 days)
-Merozoites (from liver cell replication) are released from liver and invade RBC's
-Replicate in erythrocytes and rupture them causes, fever, rigors, sweats
-Reinfects blood cells
-Some merozoites mature into male or/and? female gametocytes which are source of sexual replication in mosquito salivary gland

body can keep under control and have low levels of circulating protozoa

6

Differences between plasmodium falciparum and vivax

Falciparum: able to infect any RBC; changes membrane proteins, causing capillary adherence, blocking blood flow; sequestration in capillaries in brain and kidneys; death from coma and renal failure
Vivax: Young RBC's; no RBC sequestration; has hypnozoites that remain in liver and cause relapse

7

Malaria treatment

P. falciparum: Qunine and doxycycline or artemether+ lumefantrine to kill merozoites

P. vivax: chloroquine, primaquine to kill dormant hypnozoites

8

Malaria prevention

Avoid malarious areas; mosquito control; bed nets, long sleeves etc; insect repellant; doxycycline, mefloquine

9

Dengue fever: features; incubation; symptoms

RNA virus, aedes mozzy, multiplies in macrophages
2-7 days
Breakbone fever: muscle aches, mylgia, bone pain
1 week to recover

10

Salmonellae

Enteritidis: from animals and birds, infects mucosa in colon= colitis. gastroenteritis

Typhi: from people and infects peyers patches (terminal ileum)- causing bactaraemia and septicaemia. Typhoid fever

11

Typhoid fever presentation and treatment

fever, rigors, sweats, cough, headache, confusion, ot usually diarrhoea but constipated
Risk of peritonitis or ileal vessel erosion= bleeding
Long term bladder colonisation

Treat with ceftriaxone IV or ciprofloxacin O.