Infections On Surfaces And Travel Related Infections Flashcards
Which viruses are most likely to infect the skin?
Papilloma
Herpes simplex
Which bacteria are most likely to infect the skin?
Gram positive - staph aureus and coagulase negative staph
Give examples of prosthetic surfaces which can get infected
Intravascular lines Peritoneal dialysis catheters Prosthetic joints Cardiac valves Pacing wires Endovascular grafts Shunts
Give examples of pathogens likely to cause endocarditis if >1 year post-op
Strep viridans
Enterococcus faecalis
Staph aureus
Candida
Give examples of pathogens likely to cause endocarditis if <1 year post-op
Coagulase negative staph
Give the bacteria most likely to cause prosthetic joint infections
Coagulase neg staph
Staph aureus
Which organisms are most likely to infect pacemaker wires?
Coagulase neg staph
Staph aureus
Give some features of biofilms
Increases life cycle
Decreases turn over
Antibiotics won’t work on them - Abx only target actively replicating bacteria
Quorum sensing
Describe quorum sensing in biofilms
The communication between bacteria in a biofilm
Recognises if there are a lot of bacteria present
Controls: sporulation, biofilm formation and virulence factor secretion
What is a natural antibacterial that we could cover prosthetic joints/lines in?
Silver
Why is antibiotic resistance more prevalent in some countries?
In some places you can buy Abx over the counter
What might we think of if someone had been to North Africa?
malaria
What types of infection would we be thinking of if someone had been to the middle east?
Respiratory pathogens and viruses
What types of infections might we think of if someone had been to north Australia?
Malaria
Bacterial infections
What infection might we think of if someone had been to North America?
West Nile virus
What categories do we usually divide the incubation periods into?
< 10 days
10-21 days
> 21 days
(Since the symptoms began)
What type of infection is ebola?
Viral haemorrhagic fever
Define meningism
Triad of nuchal (neck) rigidity, photophobia and headache
What might we find on examination of someone with malaria?
Fever Low BP Tachycardia Bite marks Low O2 states Unwell/confused Possible hepatosplenomegaly Possible jaundice
What investigations would we do in malaria?
Hb - low (anaemia)
Platelets - low
If their travel Hx and symptoms suggest malaria, how can we rule it out?
3 negative blood films rule it out
What are the 4 main species of plasmodium?
Falciparum
Vivax
Ovale
Malariae
Which type of malaria is most common in the UK?
Plasmodium falciparum
Can malaria spread from person to person?
No
What is the incubation period of malaria?
Minimum 6 days
What is the classic triad of symptoms in malaria?
Fever
Chills
Sweats
(In a cycle)
Why is it hard to target a vaccine at malaria?
It has many different stages to its life cycle
What is the treatment for plasmodium falciparum?
Quinine and doxycycline
OR
Artesinate
What is the treatment for P. Vivax, ovale and malariae?
Chloroquine and primaquine
What other possible diagnoses should occur to you when you suspect malaria?
Typhoid
Dengue
Rickettsial infection
Non-travel related infection eg. Meningococcal sepsis
Name the 2 types of enteric fever
Typhoid
Paratyphoid
Describe the classical symptoms of enteric fever
Constipation
Abdominal cramps
Dry cough
Headache
In which disease state may a faint rose spot appear on the abdomen?
Enteric fever
Typhoid/paratyphoid
Which bacteria causes enteric fever?
Salmonella typhi
How is enteric fever spread?
Faecal oral route
What type of bacteria is salmonella typhi?
Enterobacteriaceae
Aerobic
Gram negative
Rod shaped
What is the incubation period for enteric fever?
7 - 14 days
With enteric fever, what happens to the heart rate?
Bradycardia
Which type of enteric fever is generally milder?
Paratyphoid
What is the treatment for enteric fever?
Ceftriaxone or azithromycin
7-14 days
Is there a vaccine for enteric fever?
There is a typhoid vaccine
50-75% effective
Describe a non-typhoidal salmonella infection
‘Food poisoning’
Widespread throughout out
Usually caused by salmonella typhimunum or salmonella enteritidis
Diarrhoea, vomiting, fever, abdominal pain
Generally self-limiting
Give some symptoms/signs of Dengue fever
Rash - broad, flat, macular
Fever
Severe myalgia
Headache
What infections do we need to think about if someone presents with a fever and a rash?
Dengue Childhood: Measles, rubella, parvovirus Infectious mononucleosis (glandular) Acute HIV infections Rickettsia (ticks)
Give 2 tests that need to be done to confirm dengue fever
PCR
Serology IgM
How is dengue fever spread?
Mosquitoes
How do we treat dengue fever?
Supportive treatment only
Usually self limiting (improvement seen 3-4 days after getting the rash)
Reinfection with a different serotype of dengue fever is worse that the original infection, why?
Can lead to:
Haemorrhagic fever
Shock syndrome
What is myiasis?
Fly larvae
Biting flies lay eggs on you or your clothes
Larvae bury into skin and then pop out if they survive
What does MERS-CoV stand for and what animal is it associated with?
Middle East Respiratory Syndrome
Camels
Describe the ebola virus
Filovirus
Flu like illness with vomiting, diarrhoea, headache, confusion and a rash
Internal/external bleeding at 5-7 days
Spread by direct contact with bodily fluids
Describe the Zika virus
Arbovirus - mosquito
Sexually transmitted
No treatment and no vaccine available
20% of people get mild (dengue-like) symptoms
Can cause foetal loss and congenital abnormalities in pregnant women
Why shouldn’t we give primaquine to people with G6PD deficiency?
These people produce less NADPH therefore cannot reduce glutathione as readily
Primaquine causes oxidative damage to RBCs that their body cannot fix
Heinz bodies form -> haemolytic anaemia
