Travel-related infection Flashcards
What are climate or environment related health problems?
Sunburn Heat exhaustion/heatstroke Fungal infections Bacterial skin infections Cold injury Altitude sickness
What infections can be controlled by sanitation?
Traveler's diarrhoea Typhoid Hep A or E Giardiasis Amoebiasis Helminth infections Viral gastroenteritis Food poisoning Shigella dysentery Cholera Cryptosporidiosis
What are infections controllable by immunisation?
Poliomyelitis
Diphtheria
What are infections controllable by education?
HIV
STIs
What are water related infections?
Schistosomiasis Leptospirosis Liver flukes Strongyloidiasis Hookworms Guinea worms
What are arthropod-borne infections?
Malaria Dengue fever Rickettsial infections Lesihmaniasis Trypanosomiasis Filariasis Onchocerciasis
What are emergency infectious diseases?
Zika Ebola MERS-CoV Swine flu Avian flu SARS West Nile virus
What is the main imported disease?
Malaria
What is the malaria vector?
Female mosquito
What is the malaria life cycle?
Transmission of sporozoites by bite
Sporozoites travel to liver + enter hepatocytes
Sporozoites multiply asexually, schizonts formed containing thousands of merozoites
Release of merozoites into bloodstream
Merozoites enter erythrocytes and mature to trophozoites, rec cell schizonts formed containing thousands of merozites, release of merozoites into bloodstream causes fever and manifestations of malaria
What are the 5 species of malaria?
Plasmodium falciparum P. vivax P. ovale P. malariae P. knowlesi
What is the potential y severe species of malaria?
P. falciparum
What are the symptoms of malaria?
Fever Rigors Aching bones Abdo pain Headache Dysuria Frequency Sore throat Cough
What are the signs of malaria?
None
Splenomegaly
Hepatomegaly
Mild jaundice
What are complications of malaria?
Cerebral malaria (encephalopathy) Blackwater fever Pulmonary oedema Jaundice Severe anaemia Algid malaria
What is blackwater fever?
Severe intravascular haemolysis High parasitaemia Profound anaemia Haemoglobinuria Acute renal failure
How is malaria diagnosed?
Thick & thin blood films
Quantitative buffy coat (QBC)
Rapid antigen tests
What is complicated malaria?
1+ of:
Impaired consciousness or seizures Hypoglycaemia Parasite count >2% Haemoglobin <8mg/dL Spontaneous bleeding/DIC Haemoglobinuria Renal impairment or pH<7.3 Pulmonary oedema or ARDS Shock
What are drugs for malaria?
Quinine
Artemisinins
What are treatment options for uncomplicated P.falciparum malaria?
*Riamet = 3 days Eurartesim = 3 days Malarone = 3 days **Quinine = 7 days Plus oral doxycycline
What are treatment options for complicated/severe P.falciparum malaria?
IV artesunate
IV quinine
plus oral doxycycline
What are treatment options for non-P.falciparum forms of malaria?
Chloroquine = 3 days Riamet = 3 days add Primaquine (14 days)
What are malaria control programmes?
Drain standing water - mosquito breeding sites
Larvacides
Mosquito killing sprays
Human behaviour: nets, mesh
What bacteria cause typhoid fever?
Salmonella typhi
Salmonella paratyphi
What causes typhoid?
Poor sanitation
Unclean drinking water
What are the clinical features of typhoid?
1st week: headache, fever, abdominal discomfort, constipation, dry cough, relative bradycardia, neutrophilic, confusion
2nd week: fever peaks 7-10days, rose spots, diarrhoea begins, tachycardia, neutropenia
3rd week: intestinal bleeding, perforation, peritoneum, metastatic infections
4th week: relapse or recovery
What is the incubation period for typhoid?
7 days - 4wks
What are the investigations for typhoid?
Lab cultures blood, urine, stool & bone marrow
Mainly salmonella typhi
What is the treatment of typhoid fever?
Oral azithromycin
IV ceftriaxone
What is the commonest human arbovirus infection?
Dengue
How is dengue transmitted?
Mosquito
What are signs/symptoms of dengue?
Sudden fever Severe headache, retro-orbital pain Severe myalgia and arthralgia Macular/maculopapular rash Haemorrhagic signs: petechiae, purpura, positive tourniquet test
What is the positive tourniquet test?
More than 10 to 20 petechiae per square inch
How can dengue be diagnosed clinically?
Thrombocytopenia
Leucopenia
Elevated transaminases
Positive tourniquet test
How can dengue be diagnosed in the lab?
PCR
Serology
What are complications of dengue?
Dengue haemorrhagic fever (DHF)
Dengue shock syndrome (DSS)
What is the management of dengue?
IV fluids
Fresh frozen plasma
Platelets
What is the prevention for dengue?
Avoid bites
New vaccine - limited use
How is schistosomiasis transmitted?
Parasites in infected fresh water snails
What are the 3 most common schistosomiasis species?
Schistosoma haematobium
S. mansoni
S. japonicum
What are the clinical features of schistosomiasis?
Swimmers itch - 1st few hours
Invasive stage - after 24hrs = cough, abdominal discomfort, splenomegaly, eosinophilia
Katayama fever - after 15-20 days = freer, urticaria, lymphadenopathy, splenomegaly, diarrhoea, eosinophlia
Acute disease - after 6-8wks = eggs deposited in bowel (dysentry) or bladder (haematuria)
Chronic disease
What is the diagnosis for schistosomiasis?
Clinical
Antibody tests
Ova in stools/urine
Rectal snip
What is the treatment for schistosomiasis?
Praziquantel
What is the other name for Rickettsiosis?
Typhus
What is the most common typhus imported to UK?
Tick typhus
What are the clinical features of tick typhus?
Abrupt onset swinging fever Headache Confusion Endovasculitis Rash (macular, petechial) Bleeding
What is the diagnosis for tick typhus?
Clinical features
Serology
What is the treatment for tick typhus?
Tetracycline
What are viral haemorrhage fevers?
Ebola
Congo-Crimea haemorrhagic fever
Lassa fever
Marburg disease
What is the max incubation period for viral haemorrhagic fevers?
3 weeks
What is Zika transmitted by?
Mosquitos
How is Zika transmitted?
Sexual contact
Blood transfusion
What are the clinical features of Zika?
No or mild symptoms Headache Rash Fever Malaise Conjunctivitis Joint pains
In pregnancy:
Microcephaly
Neuro problems
What can Zika cause as a complication?
Guillain-Barre syndrome
When examine what tropical disease should you think of for: rash?
Typhoid
Typhus
Dengue
When examine what tropical disease should you think of for: jaundice?
Hepatitis
Malaria
Yellow fever
When examine what tropical disease should you think of for: lymph nodes?
Leishmania
Trypanosomiasis
When examine what tropical disease should you think of for: liver problems?
Malaria
Typhoid
Amoebic abscess
When examine what tropical disease should you think of for: splenomegaly?
Visceral leishmaniasis
Typhoid
Malaria
What investigations should you do if you suspect a tropical disease?
FBC Malaria films LFTs Stool microscopy & culture Urine analysis & culture Blood culture CXR Specific tests
