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1

What are the relevant patient factors to travel related infections?

Calendar and relative time

Recent places

2

Why is a patient's travel history important?

Imported diseases that are rare or unkown in the UK can occur, Infection DDx must be broadened to include infections endemic to areas travelled recently by patient

Different strains of pathogen are/have potentially:

Antigenically different

Impacting on protection and detection

Antibiotic resistance differences

Guides necessary ward and lab based infection prevention

3

What are the key aspects of a patients travel history?

Where? (Be exact)

When?

How (Direct or via?)

Accomodation

How long?

Specific risks (including sexual contact)

Preventative measures taken (E.g. Doxycycline)

4

What are the 4 main species of micro-organism that can cause malaria?

Plasmodium:

- Falciparum

- Vivax

- Ovale

- Malariae

5

escribe the spread of malaria

Female mosquitos are the vector

No case to case spread

6

Where does malaria occur?

The tropics:

Africa, Asia, Middle east, South and Central America

7

Describe a typical malaria history

Headache

Cough

Fatigue and Malaise

Arthralgia (joint pain)

Myalgia

Fever, Chills and Sweats which cycle every 3rd or 4th day

All occuring 1-3 wks after bite (incubation period)

8

What might be the common findings of an examination of patient with malaria?

Fever

Possible Splenomegaly

Coma

Resp distress (metabolic acidosis, pulm oedema)

9

Who is responsible for treatment of malaria?

Infectious disease physician

 

10

Describe malaria management

Blood smear to detect parasites

FBC, Urea and Electrolytes, LFTs, Glucose

Head CT if CNS symptoms

Treatment is species dependent:

- P. falciparum - quinine or artemisinin

- P. vivax, ovale, malariae - chloroquinine +/- primaquine

11

Describe a cycle of Malaria transmission/infection beginning from a mosquito biting an infected human

Mosquito acts as vector, infected blood passes into the mosquito gut and can be passed on via the mosquitos saliva

A mosiquto bites a human and the malarial parasite enters the blood through mosquito saliva

Parasite takes root in the liver (Exo-erythrocytic phase)

Parasite is released into the blood (Erythrocytic phase)

Mosquito can bite newl infected human and further pass it on

12

Outline the prevention of malaria

ABC

Assess risk:

- Knowlegde of risk areas for regular or returning travellers

Bite prevention:

- Repellant, aqequate clothing, nets

- Chemoprophylaxis before travel

Chemoprophylaxis:

- Specific to region

Stats and continues before/after return

 

13

What is enteric fever?

General term for Typhoid and Paratyphoid fever

 

14

Describe the epidemiology of enteric fever worldwide and in the UK

Worldwide:

Widespread in areas with poor sanitation

21 million cases per year, mostly children

UK:

500 cases/yr (travel related - mainly India)

 

15

What is the mechanism of infection of enteric fever?

Faeco-oral

Source is cases or carriers only

16

What is the causative organism for enteric fever?

Salmonella enterica serotypes

Commonly Salmonella typhii/paratyphii A, B or C

Aerobic gram negative rods

Non-lactose fermenting

17

What are the virulence factors of Salmonella enterica subsp. that commonly cause enteric fever?

Gram negative endotoxin (VI antigen)

Invasin (to allow intracellular growth)

Fimbriae (small hairlike processes) allow adherence to ileal peyer's patches

18

What are the symptoms and signs of enteric fever?

Systemic disease w/ fever and headache

Abdominal discomfort

Constipation

Dry cough

Rash

Hepatosplenomegaly

Bradycardia

Complications can include haemorrhage and perforation of bowel

 

19

What investigation might be performed in a patient with suspected enteric fever?

What would be found in a patient with enteric fever?

Investigations:

FBC, WBCC, Urea and Electrolytes, LFTs, Blood and stool culture

Results:

Moderate anaemia

Relative lymphopenia

Raises LFTs

Bacteria in blood and stool culture (S. Enterica subsp.)

 

20

What is the current treatment for enteric fever?

Ceftriaxone or azithromycin for 7-14 days

21

Describe the preventative measures for enteric fever

Hygiene:

Food and water hygiene precautions (boil water etc)

Vaccine:

Used for high risk travel and lab personnel

VI capsular polysaccharide antigen or live attenuated virus

50-75% protective

22

Apart from enteric fever, what other common disease is caused by salmonella spp.?

Give common causative organisms, symptoms and complications

Food poisoning

Widespread distribution including UK (non-travel related)

Organisms:

Commonly caused by S. typhirium/enteritidis

Symptoms:

Diarrhoea

Fever

Vomiting

Abd. pain

Complications:

generally self limiting but bacteriaemia and deep seated infection may occur

 

23

What is zoonosis?

Any process whereby an infectious disease is transmitted from animal to human

24

Give an example of a zoonosis disease

Include the common causative organisms and it's distribution worldwide

Brucellosis

Organisms:

Brucella abortus (cattle) and B. melintensis (goats and sheep)

Gram negative coccobascillus

Distribution:

S. Europe

Africa

Asia

C&S America

25

With regards to brucellosis describe the:

- Transmission

- Symptoms

- Diagnosis

- Treatment

Transmission:

Through skin breaks or the GI tract (Milk)

Symptoms:

Non specific, febrile (undulant fever, rising and falling)

Bone/Joint involvement

Epidydimitis

Diagnosis:

Generally from blood culture

Treatment:

Doxycycline and rifampicin

26

Why is travel history important in a patient that potentially has a severe/high risk disease?

Assessment of travel guides possible diagnosis

Also allows us to assess possibility of high risk infection being present

27

What precautions might be taken with someone with a suspected high risk of a travel related infection?

Requirement to consider isolation

Additional protections afforded to clinicians/lab staff handling high risk specimens

28

Give an example of two types of novel emergent viruses that caused pandemics

Influenza:

E.g. H1N1 swine flu in 2009

Coronavirus:

E.g. SARS-CoV in 2003 (severe acute respiratory syndrome)

29

Give examples of viruses, vectors and diseases that cause haemorrhagic fevers

Your examples may vary

Filoviridae - Bat - Ebola haemorrhagic fever

Flaviviridae - Mosquito - Dengue and Yellow haemorrhagic fever

30

What are the symptoms of Ebola?

Flu-like

Vomiting

Diarrhoea

Haedaches

Confusion

Rash

Internal/external bleeding at 5-7 days