Session 8 Flashcards
(73 cards)
1
Q
What causes an increase in travel infections?
A
- Exotic destination
- More co-morbidities making people more susceptible
- Migration
- Emerging infections
2
Q
What are travel infections in terms of patient factors?
A
- Calendar/relative time of the exposure and travel
- Place recency
(incubation period)
3
Q
What are rickettsia/spirochaete?
A
Intracellular bacteria that can spread and include a vector to transmit the infection to humans (ticks)
4
Q
What parasitic infections are transmitted via vectors?
A
Protozoa + Helminths
5
Q
Why is the travel history important?
A
- Recognise important diseases that are rare in UK
- Prevent infections on the ward and lab
- Identify the strain of pathogen (eg. antigenic differences and antibiotic resistance) that may have changed abroad
6
Q
What does an animal bite put you at a risk for?
A
Rabies
7
Q
What does a rodent put you at a risk for?
A
Leptospirosis
8
Q
What can mosquito/insect bites put you at risk for?
A
Malaria, dengue
9
Q
What can a tick bite put you at risk for?
A
Lyme disease, rickettsia
10
Q
Where do most of the ‘exotic’ diseases come from?
A
Sub-saharan Africa
South-East Asia
Central/South America
11
Q
What if exposure in last 10 days?
A
Likely to be viral/rickettsia as they develop and present quicker
12
Q
What if exposure in 10-21 days?
A
Parasites and bacteria more likely
13
Q
What if exposure in 21+ days?
A
More complicated bacteria and parasites
14
Q
What are the most common symptoms to look out for?
A
- Resp (cough)
- GI
- Skin rash
- Jaundice (Hep A + E common travel infections)
- CNS (headaches/meningism)
- Haematological complications (splenomegaly or haemorrhage)
- Eosinophilia
15
Q
How can travel infections be commonly acquired?
A
- Food/water
- Insect bites
- Swimming
- Sexual contact
- Animal contact
- Recreational
16
Q
What do dead/slaughtered animals put you at risk for?
A
Anthrax (skin ulceration and pneumonia), Ebola
17
Q
What do farms put you at risk for?
A
Q- fever
18
Q
What do game parks put you at risk for?
A
Rickettsia
19
Q
What does fresh water put you at risk form?
A
Schistosomiasis
20
Q
What other aspects of travel history are important?
A
- Have they had any pre-travel vaccinations or preventative measures
- Did they have any unwell companions or contacts?
- What was their healthcare exposure?
21
Q
What can undercooked fish/meat cause?
A
Salmonella
22
Q
How does malaria appear on a blood film?*
A
Slide 20.
- Small ‘nuclei’ where they shouldn’t be there
- Semicircle and two dots
- More than one in many cells
- Changed RBC shapes
23
Q
What are the main species of plasmodium causing malaria?
A
Falciparium (75% of cases and most dangerous) and vivax (most common)
Also ovale, malariae, knowlesii
24
Q
What is the vector for malaria?
A
Female Anopheles mosquito
25
Where is the highest risk of transmission of malaria?*
- South-East Asia
- South America
- Sub-Saharan Africa (MOST COMMON)
26
What is the incubation period of malaria?
```
Falciparium = up to 4 weeks
Vivax/ovale = up to 1+ year (may stay dormant and reoccur)
```
27
What are the symptoms of malaria?
- Fever, chills and sweats
- Headache
- Fatigue
- Splenomegaly
- Nausea and vomiting
Often few sides on examination.
28
What is severe falciparum malaria?
Parasites >2%
29
What are the symptoms of severe falciparum malaria?
- Tachycardia, hypotension, arrhythmia
- ARDS
- Bilirubin
- Acute kidney injury
- Convulsions
- Thrombocytopenia
- DIC
- Hypoglycaemia
- Metabolic acidosis
30
What is the cycle of malaria?*
Slide 26! (liver cells are infected and can reproduce in red blood cells)
31
What investigations should you do if you suspect malaria?
- Three blood films need to be done
- Full blood count, liver function, glucose, coagulation
- Head CT
- CXR
32
How do you treat Plasmodium falciparum?
- Artesunate (best treatment)
- Quinine + doxycycline
ARE CHLOROQUINE RESISTANT
33
How do you treat Plasmodium vivax, ovale and malariae
- Chloroquine
| - Additional primaquine for dormant hypnozoites in liver
34
How do you prevent malaria?
- Assess risk
- Bite prevention (repellant, clothing, nets, vaccines)
- Chemoprophylaxis (start before and continue after return, for about 4 weeks)
35
Where does enteric fever (typhoid/paratyphoid) occur?
Mainly Asia (poor sanitation)
36
How is enteric fever transmitted?
- Faecal-oral from contaminated food and water
| - Sourced from either cases or carriers who are shedding bacteria (may not have symptoms)
37
What can cause enteric fever?
- Salmonella typhi
| - Salmonella paratyphi A, B, C
38
What are the virulence factors of salmonella typhi/paratyphi?
- Low infectious dose
- Survives gastric acid
- Adhere to Peyer's patches
- Reside in macrophages
39
What are the symptoms and signs of enteric fever?
- Systemic disease (sepsis)
- 7-14 day incubation
- Fever, headache, abdo pain
- Bradycardia
40
What are the complications of enteric fever?
Intestinal haemorrhage and perforation
| 10% mortality
41
What will the investigations show?
- Anaemia
- Lymphopaenia
- LFTs raised
- Blood culture positive
- Faeces, bone marrow
42
What is the treatment for enteric fever and why?
- IV ceftriaxone (cephalosporin) or azithromycin (macrolide) 7-14 days
Resistant to penicillins and increasingly resistant to floroquinolones
43
How to prevent enteric fever?
- Food and water hygiene
- Typhoid vaccine (live/capsulated antigen) for high risk people
- 50-75% effective
44
What are non-typhoidal salmonellas?
'food poisoning'
- Diarrhoea, fever
Generally self limiting unless immunocompromised (then potential bacteraemia), milder
45
What can cause a fever and rash?
- Childhood viruses (measles, rubella)
- Infectious mononucleosis
- Acute HIV
- Rickettsia
46
What is a macular-papular rash?*
- Individual spots coalescing into larger areas
| - Mostly flat but some raised
47
What tests can you do for dengue?
- Dengue PCR
| - Dengue Serology
48
Where can you get dengue?
Sub and tropical regions (Africa, Asia, India)
49
What is dengue?
Mosquito-borne tropical disease causing headaches, high fever, skin rash
50
What does the first dengue infection present as?
- Asymptomatic/non-specific febrile illness
- 1-5 days
- Improvement after rash
- Supportive treatment given as no specific
51
What does a re-infection with a different dengue serotype present as?
- Haemorrhagic fever (hyper-endemic)
- Dengue shock syndrome
- Antibody-dependent
52
What is myasis?*
Fly larvae infection occurring in tropical regions
- Eggs hatch and immature larvae burrow into skin
- Mature in skin
- Can mature into an adult fly and fly away
- Maggot can also disintegrate
53
What are some notifiable diseases?*
Slide 50
54
How do novel viruses emerge?
- Shifts in antigens (glycoprotein envelopes)
- Reassortment (human/animal viruses)
- Commonly respiratory viruses
55
What are the novel coronaviruses?
- SARS (Severe acute respiratory syndrome)
- MERS (Middle eastern respiratory syndrome)
- COVID-19
All can cause severe respiratory disease, and may also be asymptomatic (esp. COVID-19)
56
What is Ebola?
- Viral haemorrhagic fever
- Filovirus causing a flu-like illness with vomiting and confusion
- Internal/external bleeding
- Body fluid contact
50% FATALITY
57
What is the Zika virus?
- Virus causing mild, dengue-like symptoms
- Sexually transmitted
- Can cause congenital microcephaly and foetal loss
- No treatment or vaccine
58
Where did the first penicillin resistant Staph aureus strand get reported?
Penicillin 1941, first resistant strand a year later
59
When was the first MRSA strand reported?
The same year that methicillin was introduced
60
What are the consequences of antibiotic resistance?
- Treatment and prophylaxis failure
| - Economic costs
61
What is transferable resistance?
Bacteria transferring the genes for antibiotic resistance between each other, leading to the spread of resistance in many individuals and worldwide
62
What is multi-drug antimicrobial resistance?*
Non-susceptibility to at least one agent in three or more microbial categories
63
What is an extensive drug resistance (XDR)?*
Non-susceptibility to at least one agent but in two or fewer categories
64
What is pan-drug resistance (PDR)?*
Non-susceptibility to all agents in all antimicrobial categories
- Most serious
- Resistant to all current antimicrobial agents
65
What is the evidence that antibacterials cause resistance?
- Laboratory evidence (bio plausibility)
- Ecological studies (levels of use vs resistance)
- Individual level data (prior use in individuals with resistance)
66
What is the definition of antimicrobial stewardship?
Interventions designed to improve and measure the appropriate use of antimicrobials:
- Optimal clinical outcomes
- Minimise toxicity
- Minimise other adverse events
- Reduce cost of healthcare infections
- Limit selection for antimicrobial resistant strains
67
What are the elements of an antimicrobial stewardship programme?
- Multidisciplinary team communications
- Surveillance (process and outcome measures)
- Interventions (restrictive, persuasive)
68
What else does antimicrobial stewardship link to?
- Infection prevention
| - Environmental decontamination
69
What are the types of persuasive intervention?
Education, reminders, audits
70
What are examples of restrictive intervention?
Restricted susceptibility reporting, formulary restriction, prior authorisation
71
What are examples of structural intervention?
Computerised records, rapid lab tests, quality monitoring
72
What is measured in antimicrobial use?
- Quantity (defined daily dose)
- Antibacterial class
- Adherence to guidelines
73
What are the requirements for successful stewardship?
- Long term confirmed, appropriate resources
- Challenging inappropriate antimicrobial therapy
- Integration into patient safety
