Travel Related Infections Flashcards
What are the most significant parts of the infection model when looking at travel infections?
Person;
- Age
- Gender
- Physiological state
- Pathological state
- Social factors
Time;
- Calendar time
- Relative time
Place;
- Current
- Recent
Outline how pathogens can cause travel related infections
Bacteria (Rickettsia) and parasites (Protozoa, Helminths) are transmitted via vectors
What are 3 reasons that travel history is important?
- To recognise imported diseases (Rare/ unknown in UK)
- Infection prevention (On the ward/ in the lab)
- Different strains of pathogen exist (Variation in antibiotic resistance, impact on protection/ detection)
What are 4 guiding questions involved in taking a travel history?
Where have they been?
When did the symptoms begin?
What are the symptoms/ signs?
How did they acquire it?
What are 6 common regions associated with travel infections
- Sub Saharan Africa
- North Africa
- Southeast Asia
- South/ Central Asia
- South/ Central America
- Middle East
(Also North Australia and North America)
What are the 3 groups of incubation periods for travel related infections?
Acute: <10 days
Sub-Acute: 10–21 days
Chronic: >21 days
What are 5 types of symptoms seen in travel related infections
- Respiratory (Cough)
- GI (Diarrhoea
- Skin (Rash)
- CNS (Headache)
- Haematological (Haemorrhage/ splenomegaly/ lymphadenopathy)
What are 5 activities that can result in travel related infections
- Food/ water
- Insect/ tick bite
- Swimming
- Sexual contact
- Animal contact (Bite/ safari)
What are 3 key aspects of travel history
- Any unwell travel companions/ contacts?
- Preventative measure taken? (Pre-travel vaccination)
- Any healthcare exposure?
What is the commonest imported infection to the UK?
What is the vector for this infection?
Malaria
Female Anopheles mosquito
What are the 5 main species of Plasmodium?
Which is most dangerous?
Which one is mainly in Africa?
Which ones are mainly in India?
- Plasmodium falciparum;
- Most dangerous
- Mainly in Africa - Plasmodium vivax;
- Mainly in India - Plasmodium ovale;
- Mainly in India - Plasmodium malariae
- Plasmodium knowlesii
What is the Incubation period for malaria?
What about Plasmodium falciparum, vivax and ovale in particular?
At least 6 days
P. falciparum: Up to 4 weeks
P. vivax/ ovale: Up to 1 year+
How does Malaria present in the history and upon examination
History;
- Fever, chills and sweats in a cycle every 3rd or 4th day
Examination;
- Often few signs except fever
- May or may not have splenomegaly
What are 7 types of symptoms of Malaria due to Plasmodium falciparum presents?
- Cardiovascular (Tachycardia, Hypotension, Arrhythmia)
- Respiratory (Acute Respiratory Distress Syndrome)
- GI (Diarrhoea, Abnormal LFTs, raised Bilirubin)
- Renal (Acute kidney injury)
- Blood (Low/ normal WCC, DIC, Low platelets)
- CNS (Confusion, fits)
- Metabolic (Hypoglycaemia, metabolic acidosis)
(Possible secondary infection)
Describe the life cycle of the malaria parasite
- Parasite invades body via bite
- Travels to liver, matures
- Enters blood, attacks RBCs
How is Malaria diagnosed? Include 6 methods
- FBC
- U&Es
- Blood glucose
- Coagulation test
- Head CT (If neurological symptoms)
- Chest X Ray
What do you need to do to discount a malaria diagnosis
3 negative blood films
How do you treat Malaria due to;
- P. falciparum
- P. vivax/ ovale/ malariae
Falciparum;
- Artesunate (1st line treatment)
- Quinine + Doxycycline
Vivax/ ovale/ malariae;
- Chloroquine
- If recurrent, Primaquine
What are 3 methods of prevention of malaria
- Asses risk
- Bite prevention
- Chemoprophylaxis
What is Enteric fever?
What 2 diseases are example of enteric fever?
Which organisms cause these? Which disease is milder
A potentially fatal, multisystemic disease caused by Salmonella typhi
Typhoid;
- Salmonella typhi
Paratyphoid;
- Salmonella paratyphi A/B/C
- Milder
What are 3 high risk regions for Enteric fever?
What is the mechanism of infection?
- Asia
- Africa
- America
Faecal-oral
Describe 4 virulence factors of Enteric fever
- Low infectious dose
- Survives gastric acid
- Reside within macrophages
- Fimbriae adhere to epithelium over Peyer’s patches, bacteria enter the blood
State the incubation period of Enteric fever
State 6 symptoms/ signs
7-14 days
- Fever
- Headache
- Dry cough
- Relative bradycardia
- Abdominal discomfort
- Constipation/ diarrhoea
State 3 complications of Enteric fever
- Intestinal haemorrhage
- Intestinal perforation
- Death (10%)
State 5 investigations for Enteric Fever
- FBC (Low lymphocytes, moderate anaemia)
- LFTs (Mildly raised)
- Serology (Ab detection, not reliable)
- Blood culture (Primary investigation)
- Faces/ bone marrow culture
Describe the drug resistance of the organism causing enteric fever
Outline the treatment of enteric fever
Multi-drug resistant (Including penicillins)
Usually;
- IV ceftriaxone (a cephalosporin)/ azithromycin (a macrolide) for 7-14 days
- Fluoroquinolones may work (Increasing resistance)
What are 2 methods of prevention of enteric fever
- Food and water hygiene
- Typhoid vaccine (capsular polysaccharide antigen or Live attenuated vaccine)
Suggest a non-typhoidal infection caused by Salmonella species
What are 4 symptoms
Food poisoning
- Fever
- Vomiting
- Abdominal pain
- Diarrhoea
Name 4 travel related infections that present with fever and rash
- Childhood viruses (Measles, rubella, parvovirus)
- Infectious mononucleosis
- Acute HIV
- Rickettsia (Spotted fever)
What is Dengue fever
A mosquito borne tropical disease caused by dengue virus
Commonest arbovirus) (a virus transmitted by mosquitoes, ticks, or other arthropods
How many serotypes are there of Dengue virus
What are 3 high risk regions of Dengue fever
4 serotypes
Africa
Asia
Indian subcontinent
Describe the range of symptoms of Dengue fever, if its your first time being infected
How long does it last?
When does it improve?
Ranges from asymptomatic to non-specific febrile illness (Sudden fever)
- Lasts 1-5 days
- Improves 3-4 days after a rash
State 2 consequences of re-infection with Dengue fever
- Dengue haemorrhagic fever (damages vessels)
- Dengue shock syndrome (Above + weak rapid pulse)
What is Myiasis
Infection with a fly larva
What disease are caused by the coronaviruses;
MERS-CoV
SARS-CoV-2
MERS: Middle East Respiratory Syndrome
SARS: Coronavirus
What is Zika virus?
What are the symptoms
Name 2 complications
Is there a treatment or vaccine
An arbovius transmitted via Aedes mosquito and sexual transmission
Mild, dengue link (only 20%)
Congenital microcephaly, foetal loss
No treatment, no vaccine
