Travel Related Infections Flashcards
Why are travellers vulnerable to infection?
- Temptation to take risks away from home (food, water, animals, sex)
- Different epidemiology of some diseases (HIV, TB, polio, diphtheria)
- Incomplete understanding of health hazards
- Stress of travel
- Refugees: (deprivation, malnutrition, disease, injury)
What infections are common worldwide?
- Influenza
- Community acquired pneumonia
- Meningococcal disease
- Sexually transmitted diseases
Give examples of climate/environmental relayed health problems.
- Sunburn
- Heat exhaustion and heatstroke
- Fungal infections
- Bacterial skin infections
- Cold injury
- Altitude sickness
What infections are controllable by public heath measures regarding sanitation??
- Travelers’ diarrhoea
- Typhoid
- Hepatitis A or E
- Giardiasis
- Amoebiasis
- Helminth infections
- Viral gastroenteritis
- Food poisoning
- Shigella dysentery
- Cholera
- Cryptosporidiosis
What infections are controllable by public heath measures regarding immunisations?
- Poliomyelitis
- Diphtheria
What infections are controllable by public heath measures regarding education?
- HIV
- STDs
Give examples of water-related infections
- Schistosomiasis
- Leptospirosis
- Liver flukes
- Strongyloidiasis
- Hookworms
- Guinea worms
Give examples of arthropod-borne infections.
- Malaria (mosquitos)
- Dengue fever (mosquitos)
- Rickettsial infections (ticks: typhus)
- Leishmaniasis (sand flies: Kala-azar)
- Trypanosomiasis (tsetse fly: sleeping sickness)
- Filariasis (mosquitoes: elephantiasis)
- Onchocerciasis (black flies: River Blindness)
Give some examples of some emerging infectious diseases worldwide.
- Zika: Latin America, Caribbean
- Ebola virus disease: West Africa
- MERS-CoV: Middle East
- Swine ‘flu (H1N1): worldwide
- Avian ‘flu (H5N1 and H7N9): China
- SARS: Far East, worldwide
- West Nile Virus: USA
Give examples of some important tropical disease to be aware of.
- Malaria
- Typhoid
- Dengue Fever
- Schistosomiasis
- Rickettsiosis
- Viral haemorrhagic fevers
- Zika fever
What is the epidemiology of malaria?
United Kingdom (HPA, 2015)
- 1400 cases/year
- 6 deaths/year
Worldwide (WHO, 2012)
- 207 million cases/year
- 627,000 deaths/year
What is the malaria vector?
The female anopheles mosquito
Describe the lifecycle of malaria.
- Mosquito bites human and injects sporozoites that migrate to the liver
- Sporozoites become merozoites
- Merozoites enter circulation with RBC and mature to male and female gametocytes
- Gametocytes for zygotes which mature to sporozoites
- Sporozoites transferred to mosquito when they bite humans
What are the 5 species of malaria?
Potentially severe
-Plasmodium falciparum
Benign
- Plasmodium vivax
- Plasmodium ovale
- Plasmodium malariae
- Plasmodium knowlesi
What symptoms can malaria present with?
- Fever
- Rigors
- Aching bones
- Abdominal pain
- Headache
- Dysuria
- Frequency
- Sore throat
- Cough
What signs can malaria present with?
- None
- Splenomegaly
- Hepatomegaly
- Mild jaundice
What are the possible complications of malaria?
- Cerebral malaria (encephalopathy)
- Blackwater fever
- Pulmonary oedema
- Jaundice
- Severe anaemia
- Algid malaria
How does cerebral malaria present?
- Hypoglycaemia
- Convulsions
- Hypoxia
How does Blackwater fever present?
- Severe intravascular haemolysis
- High parasitaemia
- Profound anaemia
- Haemoglobulinuria
- AKI
What is algid malaria?
Gram negative septicaemia
How is malaria diagnosed?
Thick & thin blood films
-Giemsa, Field’s stain
Quantitative buffy coat (QBC)
-Centrifugation, UV microscopy
Rapid antigen tests
- OptiMal
- ParaSight-F
How is the severity of malaria assessed?
Complicated malaria= 1 or more:
- Impaired consciousness or seizures
- Hypoglycaemia
- Parasite count 2% or higher
- Haemoglobin 8mg/dL or less
- Spontaneous bleeding / DIC
- Haemoglobinuria
- Renal impairment or pH <7.3
- Pulmonary oedema or ARDS
- Shock (algid malaria)
What are the treatment options for uncomplicated P, falciparum malaria?
- Riamet (3 days)
- Euartesim (3 days)
- Malarone (3 days)
- Quinine (7 days) plus oral doxycycline or clindamycin
What are the possible side effects of oral quinine?
- Nausea
- Tinnitus
- Deafness
- Rash
- Hypoglycaemia
What are the treatment options for complicated or severe P falciparum malaria?
- IV artesunate
- IV quinine plus oral doxycycline or clindamycin
What are the possible side effects of IV quinine?
- Cardiac depression
- Cerebral irritation
- N+V
How is malaria caused by organisms other than P falciparum treated?
- Chloroquine (3 days)
- Riamet (3 days)
- Add primaquine (14 days) in vivax and ovale to eradicate liver hypnozoites
What programmes are there in place to control malaria?
- Drainage of standing water to prevent mosquito breeding sites
- Larvacides
- Mosquito killing sprays
- Human behaviour including bed nets and mesh windows
What organisms cause typhoid (enteric) fever?
- Salmonella typhi
- Salmonella paratyphi
What is the epidemiology of typhoid?
- Global cases: 27 million infections/yr
- Global deaths:over 200,000/yr
- UK cases: 500/yr