Travel related infections Flashcards
1
Q
What makes travelers more vulnerable to infection?
A
- Temptation to take risks away from home (sex, food)
- Different epidemiology of some diseases
- Incomplete understanding of health hazards
- Stress of travel
- Refugees: deprivation, malnutrition
2
Q
What infections are common worldwide?
A
- Influenza
- Community acquired pneumonia
- Meningococcal disease
- STIs
3
Q
What are some climate/environmental related health problems?
A
- Sunburn
- Heat exhaustion
- Fungal infections
- Bacterial skin infections
- Cold injury
- Altitude sickness
4
Q
What are infections controlled by public health measures? Eg sanitation immunization education
A
Sanitation
-Travellers diarrhoea, viral gastroenteritis, food poisoning, cholera, shigella dysentery, hep A or E
Immunisation
-Poliomyelitis, diphtheria
Education
-HIV, STDs
5
Q
What are some water related infections?
A
- Schistosomiasis
- Leptospirosis
- Liver flukes
- Strongyloidiasis
- Hookworms
6
Q
What are some arthropod borne infections?
A
- Malaria (mosquitoes)
- Dengue fever (mosquitoes)
- Rickettsial infections (ticks)
- Leishmaniasis (sand flies)
- Filariasis (mosquitoes)
7
Q
What are some infectious diseases?
A
- Zika: Latin America, Caribbean
- Ebola: W Africa
- MERS-CoV: Middle East
- Swine flu: worldwide
- Avian flu: China
- SARS: worldwide
- West Nile virus: USA
8
Q
What are some important tropical diseases?
A
- Malaria
- Typhoid
- Dengue fever
- Schistosomiasis
- Rickettsiosis
- Viral haemorrhagic fevers
- Zika fever
9
Q
How many reported cases per year is there of malaria?
A
200 million cases per year. Most common in Africa, Latin America, India
10
Q
What is the life cycle of malaria?
A
- Mosquito infects human
- Human carries malaria in blood
- Female mosquito bites human and now carries malaria parasite
- Gives birth and the child also has malaria parasite
- Goes off to infect other humans
11
Q
What are the 5 species of malaria parasite?
A
Potentially severe
-Plasmodium falciparum
Benign
-Plasmodium vivax/ovale/malariae/knowlesi
12
Q
What are symptoms of malaria?
A
- Fever
- Rigors
- Aching bones
- Abdo pain
- Headache
- Dysuria
- Frequency
- Sore throat
- Cough
13
Q
What are signs of malaria?
A
- Can be none
- Splenomegaly
- Hepatomegaly
- Mild jaundice
14
Q
What are some complications of malaria?
A
- Cerebral malaria (encephalopathy): convulsions, hypoxia
- Blackwater fever: severe haemolysis, high parasitaemia, acute renal failure, haemoglobinuria
- Pul. oedema
- Jaundice
- Severe anaemia
- Algid malaria (gram -ve septicaemia)
15
Q
How is malaria diagnosed?
A
- Thick and thin blood films (Giemsa, Field’s stain)
- Quantitative buffy coat (centrifugation, UV microscopy)
- Rapid antigen tests (OptiMal, ParaSight-F)
16
Q
There is a severity assessment for malaria. Having ‘complicated malaria’ = one or more of what?
A
- Impaired consciousness/seizures
- Hypoglycaemia
- Parasite count at least 2%
- Haemoglobin 8mg/dL or less
- Renal impairment/pH <7.3
- Pul oedema or ARDS
- Shock (algid malaria)
17
Q
What are treatment options for uncomplicated P. falciparum malaria?
A
- Riamet 3 days
- Eurartesim (artemisinin) 3 days
- Malarone 3 days
- Quinine 7 days plus oral doxycycline (or clindamycin)
18
Q
What are treatment options for complicated/severe P. falciparum malaria?
A
- IV artesunate (unlicensed in UK)
- IV quinine plus oral doxycycline (or clindamycin)
19
Q
Treatment of P. vivax/ovale/malariae/knowlesi malaria?
A
- Chloroquine 3 days
- Riamet 3 days
- Add primaquine (14d) in vivax and ovale to eradicate liver hypnozoites
20
Q
What are some malaria control programmes?
A
- Mosquiro breeding sites (draining standing water)
- Larvacides
- Mosquito killing sprays
- Human behaviour (bed nets, mesh windows)
21
Q
Typhoid fever is widespread and happens due to poor sanitation and unclean drinking water. What organisms cause this?
A
- Salmonella typhi
- Salmonella paratyphi
22
Q
What is the incubation period for typhoid fever?
A
1-4 weeks
23
Q
What clinical features are seen in the first week of disease onset?
A
- Fever
- Headache
- Abdo discomfort
- Constipation
- Dry cough
- Relative bradycardia
- Neutrophilia
- Confusion
24
Q
What clinical features are seen in the second week of disease onset?
A
- Fever
- Rose spots
- Diarrhoea
- Tachycardia
- Neutropenia
25
What clinical features are seen in the third week of disease onset? (complications arise)
- Intestinal bleeding
- Perforation
- Peritonism
- Metastatic infections
26
What clinical features are seen in the fourth week of disease onset?
Usually recovery begins. 10-15% relapse
27
How do you diagnose typhoid fever?
Clinical
-Spot evolution of features
Lab
- Blood/urine/stool/bone marrow culture
- Looking for Salmonella typhi/paratyphi
28
How do you treat typhoid fever?
- Oral azithromycin
| - IV Ceftriaxone (esp if complicated)
29
Dengue fever is the commonest human arbovirus infection. How is it transmitted?
Aedes aegypti (type of mosquito)
30
What are the symptoms and signs of classical dengue fever?
- Sudden fever
- Sudden headache, retro-orbital pain
- Severe myalgia and arthralgia
- Macular/maculopapular rash
- Haemorrhagic signs: petechiae, purpura, positive tourniquet test
31
How is dengue fever diagnosed?
Clinical
- Thrombocytopenia
- Leucopenia
- Elevated transaminases
- Positive tourniquet test
Lab
- PCR
- Serology
32
What is the management of Dengue fever?
No specific therapeutic agents
Complications
- Dengue haemorrhagic fever
- Dengue shock syndrome
- Rx: IV fluids, fresh frozen plasma, platelets
Prevention
- Avoid bites
- New vaccine
33
Schistosomiasis is spread via freshwater snails. What are the different water born parasites that cause this?
- Schistosomiasis haematobium (found in urine and faeces)
- Schistosomiasis mansoni (found in faeces)
- Schistosomiasis japonicum (found in urine and faeces)
34
What is the schistosomiasis life cycle?
- Infected snails penetrate human skin while swimming etc
- Circulate in body, lose tails to become schistosomulae in body upon penetration
- Migrate to portal blood in liver/mesenteric venules of bowel/rectum/venous plexus of bladder
- Released in urine/faeces into sea
- Parasite infects snail and cycle continues
35
The first clinical feature of schistosomiasis is swimmers itch, which presents after a few hours and stops after a day or two. What clinical features occur in the invasive stage?
- After 24h
- Cough
- Abdo discomfort
- Splenomegaly
- Eosinophilia
36
What clinical features are seen in the Katayama fever seen in schistosomiasis?
- After 15-20 days
- Prostate
- Fever
- Urticaria
- Lymphadenopathy
- Splenomegaly
- Diarrhoea
- Eosinophilia
37
What happens in acute disease of schistosomiasis? (also get chronic disease)
-Eggs deposited in bowel (dysentery) or bladder (haematuria)
38
How is schistosomiasis diagnosed?
- Clinical diagnosis
- Antibody tests
- Ova in stools and urine
- Rectal snip
39
What is the treatment for schistosomiasis?
- Praziquantel (2 doses 6hr apart)
| - Prednisolone if severe
40
What are the different types of rickettsiosis diseases and what organism causes them?
- Tick typhus (rickettsia conorii/africae)
- Rocky mountain spotted fever (rickettsia rickettsii)
- Epidemic typhus (rickettsia prowazekii)
- Scrub typhus (rickettsia tsutsugamushi)
41
What is the most common rickettsiosis disease imported to UK?
Tick typhus (from S Africa, Mediterranean, Arabian Gulf)
42
What are the clinical features of rickettsiosis?
- Abrupt onset swinging fever
- Headache
- Confusion
- Endovasculitis
- Rash (macular, petechiae)
- Bleeding
43
How is rickettsiosis diagnosed?
- Clinical features
| - Serology
44
What is the treatment for rickettsiosis?
Tetracycline
45
What are serious viral haemorrhagic fevers that are rare in the UK but deadly?
- Ebola
- Congo-Crimea haemorrhagic fever
- Lassa fever
- Marburg disease
46
How do you deal with someone who contracts a viral haemorrhagic fever?
- High security infection unit
| - Supportive treatment
47
How is Zika virus transmitted?
- Aedes mosquitoes
- Sexual contact
- Blood transfusion
48
What are the clinical features of Zika virus?
- none/mild symptoms
- Headache
- Rash
- Fever, malaise
- Conjunctivitis
- Joint pains
- Microcephaly and other neuro problems in pregnancy
- Can cause GBS
49
What treatment is there for Zika virus?
- No antiviral therapy
- Mosquito control measures
- Vaccines in development
50
What should be focused on in a patient history in a returning traveller with symptom onset?
- Is it tropical?
- Travel history
- Precautions taken
- Risks
- Symptoms/signs
- Incubation history
51
Upon examination, what diseases does rash point to?
- Typhoid
- Typhus
- Dengue
52
Upon examination, what diseases does jaundice point to?
- Hepatitis
- Malaria
- Yellow fever
53
Upon examination, what diseases does lymphadenopathy point to?
- Leishmania
| - Trypanosomiasis
54
Upon examination, what diseases does liver symptoms point to?
- Malaria
- Typhoid
- Amoebic abscess
55
Upon examination, what diseases does splenomegaly point to?
- Visceral leishmaniasis
- Typhoid
- Malaria
56
What general investigations should be done for travel acquired infections? (as well as specific investigations)
- FBC
- Malaria films
- LFTs
- Stool microscopy and culture
- Urine analysis and culture
- Blood culture
- CXR
57
General treatment for travel acquired infections?
- Isolation: (PPE, single rooms)
- Supportive measures
- Empirical treatment
- Specific treatment once diagnosis established
