Travel Related Infection Flashcards
International travel health advice
Risk assessment
Requirements change
Up-to-date information
Individual advice regarding general measures, immunisation and drug prophylaxis
Risk assessment of the traveller
Health of the traveller Areas to be visited Duration of visit Accommodation Activities Remote areas Previous immunisation and prophylaxis
Sources of information on travel advice
British national formulary
Immunisation against infectious diseases
Health information for overseas travel
Institutions e.g. schools of tropical medicine
Internet
Common immunisations for travellers
Tetanus Polio Typhoid Hepatitis A Yellow fever
Immunisation for travellers in special circumstances
Meningococcus Rabies Diptheria Hepatitis B Japanese B encephalitis Tick borne encephalitis Pneumococcus Influenza
Who should be given malaria chemoprophylaxis and how long should the course of treatment be?
Essential for all travellers to endemic areas, including children and pregnant women
Commence 1-3 weeks before travel and continue for up to 4 weeks after leaving
Examples of viral haemorrhagic fevers that travellers may be at risk of
Yellow fever Dengue haemorrhagic fever Hentavirus infections Lessa fever Marburg fever Ebola fever Congo-Crimea haemorrhagic fever
Examples of zoonoses that travellers may be at risk of
Brucellosis
Rabies
Tularaemia
Anthrax
Unfamiliar features of imported disease
Presenting features Isolation requirements Diagnostic methods Management requirements Unexpected complications
Factors increasing the vulnerability of travellers to infection
Temptation to take risks away from home
Different epidemiology of some diseases
Incomplete understanding of health hazards
Stress of travel
Refugees - deprivation, malnutrition, disease or injury
Infections common worldwide
Influenza
Community-acquired pneumonia
Meningococcal disease
STDs
Conditions caused/exacerbated climate/environment
Sunburn Heat exhaustion Heat stroke Fungal infections Bacterial skin infections Cold injury Altitude sickness
Infections controllable by sanitation
Traveller's diarrhoea Typhoid Hepatitis A or E Giardiasis Amoebiasis Helminth infections Viral gastroenteritis Food poisoning Shigella dysentery Cholera Cryptosporidiosis
Infections controllable by immunisation
Poliomyelitis
Diphtheria
Infections controllable by education
HIV
STDs
Infections transmitted in water and mud
Schistosomiasis Leptospirosis Liver flukes Strongyloidiasis Hookworms Guinea worms
Infections transmitted by arthropod vectors
Malaria Dengue fever Rickettsial infections Leishmaniasis Trypanosomiasis Filariasis Onchocerciasis
Emerging infectious diseases
Zika Ebola MERS-CoV Swine flu Avian flu SARS West Nile virus
Important tropical diseases
Malaria Typhoid Dengue fever Schistosomiasis Rickettsiosis Viral haemorrhagic fevers Zika fever
Epidemiology of malaria
Tropical
Most important imported disease
Vector is the female anopheles mosquito
Cases of malaria per year according to WHO 2012
207 million cases/year
781,000 deaths/year
Species of malaria
Plasmodium falciparum (potentially severe) Plasmodium vivax Plasmodium ovale Plasmodium malariae Plasmodium knowlesi
Symptoms of malaria
Fever Rigors Aching bones Abdominal pain Headache Dysuria Frequency Sore throat Cough
Signs of malaria
May be none
Splenomegaly
Hepatomegaly
Mild jaundice
Complications of malaria
Cerebral malaria (encephalopathy) Blackwater fever Pulmonary oedema Jaundice Severe anaemia Algid malaria
Features of cerebral malaria (encephalopathy)
Hypoglycaemia
Convulsions
Hypoxia
Features of blackwater fever
Severe intravascular haemolysis High parasitaemia Profound anaemia Haemoglobinuria Acute renal failure
Diagnosis of malaria
Thick and thin blood films
Quantitative buddy coat
Rapid antigen tests
When assessing malaria severity, one or more of what features are indicative of complicated malaria?
Impaired consciousness or seizures Hypoglycaemia Parasite count 2% or more Haemoglobin 8mg/dL or less Spontaneous bleeding Haemoglobinuria Renal impairment or pH < 7.3 Pulmonary oedema or ARDS Shock
Traditional malaria drugs
Quinine
Artemisinins
Management of uncomplicated P. falciparum malaria
Quinine 7 days plus oral doxycycline or clindamycin
Malarone 3 days
Riamet 3 days
Side effects of quinine
Nausea
Tinnitus
Deafness
Rash
Management of complicated or severe P. falciparum malaria
IV quinine plus oral doxycycline or clindamicin
Switch to oral therapy when patient is stable and able to swallow
Side effects of IV quinine
Cardiac depression
Cerebral irritation
Nausea
Vomiting
Management of P. vivax, ovale, knowlesi and malariae
Chloroquine 3 days
Riamet 3 days
Plus primaquine 14 days in vivax and ovale to eradicate liver hypnozoites
Malaria control programmes
Drainage of standing water at mosquito breeding sites
Temphos/biological management of larvicides
Mosquito killing sprays
Human behaviour e.g. bed nets, mesh windows
Adjuvant measures for malaria infection
O2 or ventilation if pulmonary oedema Maintain blood glucose Correct anaemia Dialysis if acute renal failure Exchange transfusion if high parasitaemia
Examples of prophylaxis for malaria
Malarone
Mefloquiine
Doxycycline
Causative organisms of typhoid fever
Salmonella typhi
Salmonella paratyphi
How many global cases of typhoid fever are there?
27 million infections per year
Over 200,000 global deaths per year
200 UK cases per year
Incubation period of typhoid fever
7 days - 4 weeks
Features of first week of typhoid fever
Fever Headache Abdominal discomfort Constipation Dry cough Relative bradycardia Neutrophilia Confusion
Features of second week of typhoid fever
Fever peaks at 7-10 days Rose spots Diarrhoea Tachycardia Neutropenia
Features of third week of typhoid fever
Complications Intestinal bleeding Perforation Peritonism Metastatic infections
Diagnosis of typhoid fever
Not an easy clinical diagnosis, based on evolution of features
Laboratory - blood, urine, stool and bone marrow culture
Treatment of typhoid fever
Azithromycin - drug of choice for Asian acquired uncomplicated typhoid fever
Ceftriaxone - if complicated or concerned regarding absorption
Cases of dengue fever each year
100 million infections per year
25,000 deaths per year
Features of classical dengue fever
Sudden fever Sever headache, retro-orbital pain Severe myalgia and arthralgia Macular/maculopapular rash Haemorrhagic signs e.g. petechiae, purpura, positive tourniquet test
Diagnosis of dengue fever
Clinical - thrombocytopenia, leucopenia, elevated transaminases, positive tourniquet test
Laboratory - PCR, serology
Management of dengue fever
Conservative - no specific therapeutic agents
IV fluids
fresh frozen plasma
platelets
Species causing schistosomiasis
S. haematobium
S. mansoni
S. japonicum
How is schistosomiasis contracted?
Swimming in contaminated water
Clinical features of first 24-48 hours of schistosomiasis
Swimmers itch
Features of invasive stage of schistosomiasis
After 24 hours Cough Abdominal discomfort Splenomegaly Eosinophilia
Features of schistosomiasis after 15-20 days
Katayama fevere Prostrate Fever Urticarial Lymphadenopathy Splenomegaly Diarrhoea Eosinophilia
Features of acute schistosomiasis disease
After 6-8 weeks
Eggs deposited in bowel causing dysentery or in bladder causing haematuria
Diagnosis of schistosomiasis
Clinical
Antibody test
Ova in stools and urine
Rectal snip
Treatment of schistosomiasis
Praziquantel 40mg/kg single dose
Prednisolone if severe
Features of tick typhus
Tick bite eschar
Maculopapular rash
Organisms causing rickettsiosis
R. conorii R. africae R. rickettsii R. prowazekii R. moosen R. tsutsugamushi
Clinical features of rickettsiosis
Abrupt onset swinging fever Headache Confusion Endovasculitis Rash Bleeding
Diagnosis of rickettsiosis
Clinical features
Serology
Management of rickettsiosis
Tetracycline
Management of viral haemorrhagic fevers
Rule out common severe infections Isolation in high security infection unit No specific treatment Supportive treatment May be fatal
How is zika virus transmitted?
By daytime biting aedes mosquito
Features of zika virus
No or mild symptoms Headache Rash Fever Malaise Conjunctivitis Joint pains Microcephaly and other neurological problems in unborn babies
Features of amoebic liver abscess
Fever
Right upper quadrant pain
Treatment of amoebic liver abscess
Drainage and metronidazole then diloxanide
Important features of history of a traveller returning with a febrile illness
Is it tropical Travel history Precautions taken Risks taken Symptoms Incubation periods
What travel-related infection might a rash be a sign of?
Typhoid
Typhus
Dengue
What travel-related infection might jaundice be a sign of?
Hepatitis
Malaria
Yellow fever
What travel-related infection might enlarged lymph nodes be a sign of?
Leishmania
Trypanosomiasis
What travel-related infection might a palpable liver be a sign of?
Malaria
Typhoid
Amoebic abscess
What travel-related infection might a palpable spleen be a sign of?
Kala-Azar
Typhoid
Malaria
Common investigations into travellers returning with an illness
FBC Malaria films LFTs Stool microscopy and culture Urinalysis and culture Blood cultures CXR
Specific serology tests for travellers returning with an illness
Dengue Respiratory viral/atypical Hepatitis A, B, C Tick typhus Schistosomiasis Amoebic Leptospirosis/hantavirus Brucellosis Viral haemorrhagic fevers
General treatment measures for travel related infections
Isolation
Supportive measures
Empirical treatment
Specific treatment
