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Flashcards in S9) Travel-related infections Deck (42)
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1

Which parts of the infection model are most significant when looking at travel infections?

Patient:

- Person – age, gender, physiological state, pathological state, social factors 

- Time – calendar/relative

- Place – current/previous

2

Why is travel history an important consideration?

- Recognise imported diseases (rare / unknown in UK) 

- Infection prevention on the ward/in the lab

- Different strains of pathogen (impacts on protection/detection, antibiotic resistance)

3

What are the key aspects of patient travel history?

- Any unwell travel companions /contacts?

- Pre-travel vaccinations / preventative measures?

- Healthcare exposure? 

4

What are the guiding questions when dealing with travel-related infections?

- Where have they been?

- When did the symptoms begin?

- What are the symptom/signs?

- How did they acquire it?

5

Identify some common regions which are associated with travel-related infections

- Sub-saharan Africa

- S.E .Asia

- S / C America

- N. Africa

- M. East S / C Asia

6

Identify and describe the different incubation periods for travel-related infections

- < 10 days = acute

- 10-21 days = sub-acute

- > 21 days = chronic 

7

Describe the 5 types of symptoms which result from travel-related infections

- Resp: breathlessness, cough

- GI: diarrhoea

- Skin: rash

- CNS: headache / meningism

- Haematological: lymphadenopathy / splenomegaly / haemorrhage

8

Identify 5 common activities which cause people to acquire travel-related infections

- Food/water

- Insect/tick bite

- Swimming

- Sexual contact

- Animal contact (bite/safari)

9

What is malaria?

- Malaria is a mosquito-borne infectious disease, typically transmitted through an animal vector – an infected Anopheles mosquito

- It is the commonest imported disease in the UK

10

Which species of the Plasmodium parasite cause malaria in humans?

- Plasmodium falciparum (75% – mainly Africa)

- Plasmodium vivax (~20% – mainly India)

- Plasmodium ovale  (~20% – mainly India)

- Plasmodium malariae

- Plasmodium knowlesii

11

Describe the prevalence of malaria

12

Describe how a patient with malaria presents (history & examination)

- History – fever, chills & sweats (cycle every 3rd or 4th day)

- Examination – often few signs except fever (± splenomegaly) 

13

What is the incubation period for malaria?

Minimum 6 days:

- P. falciparum – by 4 weeks

- P. vivax/ovale – up to 1 year+

14

Describe 5 types of symptoms observed in severe falciparum malaria

CVS – tachycardia, hypotension, arrhythmias

- Resp – ARDS

- GI – diarrhoea

- CNS – confusion, fits, cerebral malaria

- Blood – thrombocytopenia, DIC

 

15

Briefly, describe the life cycle of the malaria parasite

16

Identify the 8 investigations for malaria

- Blood film x3

- FBC

- U&Es

- LFTs

- Blood glucose

- Coagulation

- CXR

- Head CT (if neurological symptoms)

 

17

Describe the treatment of malaria (dependent on species)

P. falciparum (‘malignant’): artesunate, quinine + doxycycline

- P. vivax, ovale, malariae (‘benign’): chloroquine, dormant hypnozoites (liver), additional primaquine (if recurring)

18

How can malaria be prevented?

Assess risk – knowledge of at-risk areas

- Bite prevention – repellant, adequate clothing, nets

- Chemoprophylaxis – specific to region (start before & continuefor 4 weeks after return)

19

What is Enteric fever?

- Enteric fever (typhoid & paratyphoid fever) is a potentially fatal, mutisystemic ilness caused by the bacterium Salmonella typhi

- It is spread through the faecal-oral route (drinking/eating), due to poor sanitation

20

What are the high risk areas for enteric fever?

- Mainly Asia

- Also Africa & S America

21

Identify the salmonella organisms which cause enteric fever

- Typhoid fever: Salmonella typhi

- Paratyphoid fever: Salmonella paratyphi A, B or C 

22

What kind of bacteria are salmonella organisms?

Enterobacteriaceae: aerobic Gneg bacillus 

23

Describe the virulence of the salmonella organisms

Low infectious dose

- Survives gastric acid

Fimbriae adhere to epithelium over ileal lymphoid tissue (Peyer’s patches) → RE system / blood

- Reside within macrophages (liver/ spleen/ bone marrow) 

24

What is the incubation period for enteric fever?

7-14 days

25

What are the signs and symptoms of enteric fever?

- Bacteraemia & sepsis

- Fever

- Headache

- Constipation

- Dry cough

- Relative bradycardia 

26

What are the complications of typhoid fever?

- Intestinal haemorrhage

- Intestinal perforation

- 10% mortality (untreated)

27

What are the investigations for enteric fever?

- FBC (anaemia, lymphopenia)

- LFTs (raised transaminase & bilirubin)

- Blood culture

- Faecal culture

- Serology – antibody detection (not reliable) 

28

In light of its multi-drug resistance (including penicillins), outline the treatment for enteric fever

- Fluoroquinolones (e.g. ciprofloxacin) may work, but increasing resistance

- Usually, IV ceftriaxone / azithromycin for 7-14 days 

29

How can enteric fever be prevented?

- Food & water hygiene precautions

- Typhoid vaccine (high-risk travel & lab personnel)

- Capsular polysaccharide antigen / live attenuated vaccine

30

Identify some travel-related infections which present with fever & rash

- Childhood viruses – measles, rubella, parvovirus

- Infectious mononucleosis (EBV / CMV)

- Acute HIV infection

- Rickettsia (spotted fever)