Travel Related OI Flashcards
Most serious species of malarial infection?
Plasmodium falciparum
Who is at highest risk of malarial infection in UK?
Those of African and south Asian ethnicity
‘Visiting family from country of origin’
Presentation of malaria?
Fever, headache, arthralgia, myalgia, diarrhoea, sometimes features of bacterial infection
Complications of malaria?
Hyperparasitaemia, acute renal failure, hypoglycaemia, DIC, lactic acidosis, fulminant hepatic failure, cerebral malaria
Affect of malaria in pregnancy?
Anaemia, infants with LBW, prematurity and infant mortality due to Malarial parasites preferentially binding to placenta
When to consider malaria diagnosis?
Anyone with fever returning from endemic area - usually present within 3/12
How to diagnose malaria?
Thick and thin blood film
Thick - diagnose and estimate percentage of parasitaemia
Thin - for speciation
Highly sensitive and specific dipsticks also available
How is treatment for malaria chosen?
Species and severity of infection
Amodiaquine CANNOT be given with efavirenz
Treatment of uncomplicated falciparum malaria?
Oral artemether-lumefantrine (co-artem)
If weight >35kg four tablets at 0, 8, 24, 36, 48 and 60h
Alternatives - oral quinine (reacts with ritonavir so hold PI while on) for 7/7 plus doxy for 7:7
Or malarone (atovaquone proguanil) four tablets daily for 3/7
What constitutes severe falciparum malaria?
Shock, renal impairment, acidosis, pulmonary oedema, ARDS, impaired consciousness or seizures, hypoglycaemia, very low Hb (<5), haemaglobinuria, DIC
When is parenteral regime for malaria treatment used?
Severe/complicated falciparum malaria or parasitaemia >2
Parenteral treatment for falciparum malaria
IV artesunate 2.4mg/kg daily (0,12,24hr then daily 7/7) with doxycycline 20mg OD
IV quinine an alternative option with cardiac monitoring and regular glucose monitoring
What is risky about quinine?
Prologs QRS and QT intervals and can induce hypoglycaemia
What is the treatment for non-falciparum malaria?
3 days oral chloroquine (600mg stat, 300mg after 6-8hrs then 300mg daily for 2/7) followed by 14/7 primaquine to eradicate liver stages
Primaquine not needed if p.malariae
Test for G6PD and lower primaquine dose for longer if positive
Who should receive malaria prophylaxis?
All HIV+ travellers to endemic areas as they are at higher risk of severe illness
What is the ABCD of malaria prevention?
Advice for all travellers to endemic areas
Awareness of risk
Bite prevention
Chemoprophylaxis
Prompt Diagnosis and treatment
Also recommend >20% DEET, covering up, permethrin coated mosquito nets
What chemoprophylaxis is given against malaria?
Depends where you are going, for how long, national travel health network and centre can give specialist advice
Cotrimoxazole can help but patients on this should still receive standard prophylaxis
Main options - mefloquine 250mg once weekly, malarone (atovaquone proguanil) OD, doxycycline 100mg OD
Start one week prior to travel and continue 4 weeks on return
Malarone 1-2 days before travel and continue 1 week after return
Mefloquine 3-4 weeks prior to travel in case need to switch due to neuropsychiatric side effects
What are the three types of disease caused by leishmania?
- Visceral (kala azar) - systemic features fever, weight loss, helatosplenomegaly, with or without bone marrow involvement
- Mucocutaneous - destructive lesions of mucous membranes of nose or mouth
- Cutaneous - skin ulcers on limbs and face
How does cutaneous leishmaniasis present?
Papule that progresses to chronic ulcer
How is visceral leishmaniasis diagnosed?
Parasitological diagnosis may be made by microscopy, culture or PCR from-
Splenic aspirate (high sensitivity but only by practitioner trained in this technique)
Bone marrow aspirate
Biopsy specimens such as LN or skin
Histology - liver, bone marrow, LN, skin
Serological - direct agglutination, ELISA to detect antibodies to recombinant k39 antigen
How is cutaneous leishmaniasis diagnosed?
Parasitological or histological diagnosis - preferably both - may be made from skin biopsy
Raised edge of ulcer where parasites are present
Treatment of visceral leishmaniasis?
Coordinate with local tropical medicine service
Ambisome 4mg/kg for 10 doses given on days 1-5, 10, 17, 24, 31 and 38
What is the secondary prophylaxis for visceral leishmaniasis?
Pentamidine 4mg/kg every 2 weeks IV or
Ambisome iv 5mg/kg every 3 weeks
Few data of when to stop
Some authors recommend stopping if stable on ARVs and CD4 >200-350 for 3-6 months
Treatment of cutaneous leishmaniasis?
Depending on species
Discussed with tropical diseases team
Local infiltration of sodium stibogluconate - limited experience of this in HIV+ individuals
Systemic treatment
Do we give primary prophylaxis for leishmaniasis?
No.
What causes chagas disease?
Trypanosoma cruzi
Where and how is t.cruzi spread?
Central and South America
Spread by bloodsucking triatomine insects
Reactivation can occur in advanced immunosuppression for those who have lived or travelled to endemic areas
Presentation of t.cruzi?
Two main types of disease in PLWH?
- Neurological disease - SOL or meningoencephalitis - fever, headache, seizure, vomiting, focal neurological signs
- Myocarditis - often asymptomatic
How is Chagas’ disease diagnosed?
Neuro - radiology - SOL similar to toxo
CSF - lymphocytic pleocytosis, elevated protein with low glucose
Serology not diagnostic for reactivation - only indicate past exposure
PCR
Parasitological studies - thick smears, CSF smears
What should be done for asymptomatic PLWH with epidemiological risk factors for Chagas’ disease?
Test for t.cruzi to detect latent infection and if positive further evaluation in discussion with specialist tropical disease centre for neurological, intestinal and cardio logical disease
What is the treatment for Chagas’ disease?
Benznidazole 5mg/kg daily divided in two doses for 60-90 days
Higher dose may be needed in acute meningiencephalitis
Nifurtimox 8-10mg/kg/day in 3 divided doses for 60-120 days is an alternative
Should secondary prophylaxis be given after treatment for Chagas’ disease?
Benznidazole 5mg/kg 3x weekly
Unclear what optimal duration is but influenced by immunological and virological response to ARVs
Treatment for asymptomatic individuals positive for T.cruzi or with chronic disease?
Consider course of Benznidazole or nifurtimox
Weigh risk and benefit if on HAART, if not on HAART should be offered
Secondary prophylaxis can be considered for those who refuse or can’t tolerate HAART
Which dimorphic fungi are of medical importance for PLWH?
Histoplasmosis
Blastomycosis
Coccidiomycosis
Penicilliosis
Route of infection of dimorphic fungi?
Inhalation
Immunocompetent hosts develop localised pulmonary disease
Immunocompromised hosts develop disseminated disease
Where is histoplasma capsulatum car capsulatum found?
Midwestern and southeastern states of USA, the Caribbean, Central America, South America, Africa
Where is histoplasma capsulatum car duboisii found?
Mainly west and central Africa. Causes mainly extra pulmonary disease.
Where is blastomyces dermatitidis found?
Centre of USA, along st Lawrence seaway and around Great Lakes of the US and Canada
Where is coccidioides immitis found?
Southwestern parts of the USA and northern Mexico
How might coccidioidomycosis present?
Either asymptomatic or pneumonic illness in post HAART era
Pre HAART - eosinophilia, meningitis, weight loss, fever, cavities on CXR
Features of disseminated histoplasmosis
Fever, weight loss, rash.
CXR - interstitial nodular or military infiltrates, occasionally more formal
May be asssociated with oropharyngeal and gastrointestinal ulceration
Hepatosplenomegaly
Meningitis, endocarditis, involvement of adrenal gland
Sepsis syndrome, hypotension
Features of disseminated blastomycosis
Neurological disease
Which dimorphic fungi infection might give rise to a high LDH >600?
Histoplasmosis
How should dimorphic fungi infections be diagnosed?
Culture from sputum, BAL or biopsy - can take up to 4 weeks - or identification of the yeast in specimen
In disseminated disease cultures of bone marrow frequently positive and blood cultures may also be diagnostic
A polysaccharide test for h.capsulatum var capsulatum now available and useful in patients with disseminated disease (mainly only available in US)
Treatment for localised histoplasmosis or blastomycosis?
Itraconazole 200mg BD
With therapeutic monitoring
Treatment for localised coccidioidomycosis?
Fluconazole 400-800mg OD
Treatment for mild disseminated histoplasmosis?
Mild - itraconazole
Treatment for mod/severe disseminated histoplasmosis, disseminated blastomycosis, disseminated coccidioidomycosis?
Ambisome induction 3mg/kg/day for 2 weeks followed by oral itraconazole for 10 weeks (histo) fluconazole (coccidioidomycosis)
For histoplasmosis with CNS disease increase to 5mg/kg/day for 4-6 weeks followed by 800mg of fluconazole - better cns penetration
Is primary prophylaxis indicated for dimorphic fungi infections?
No
When can secondary prophylaxis for dimorphic fungi infections be discontinued?
Antifungal therapy at least 12 months
HAART at least 6 months
Fungal blood culture negative
Histoplasma urinary and serum antigen results below limit of detection
CD4 >150
When to start HAART in patients with dimorphic fungi infection?
Within 2 weeks
What organism causes penicilliosis?
Penicillium marneffei
Where does penicilliosis occur?
South east Asia and southern china.
Northern provinces of Thailand.
Increasing recognition of infection in India.
How does penicilliosis present?
Fever, weight loss, nonproductive cough, lymphadenopathy, hepatosplenomegaly and anaemia
Multiple papular skin lesions with central necrotic umbilication - face, neck, trunk, upper limbs
Does penicilliosis need treating?
Yes - disseminated penicilliosis infection almost invariably fatal
CXR findings in patients with penicilliosis
Interstitial lesions, cavities, fibrotic lesions, mass lesions
How is penicilliosis diagnosed?
Direct microscopy of smears from skin or other lesions - separate yeast forms
Cultures from bone marrow, lymph nodes, skin - characteristic red colour on plates and diamorphism which means the fungus changes to a hyphae form at lower temps
Why is it important to culture lesions I. Penicilliosis?
Histoplasmosis and cryptococcus may have similar clinical manifestation
Treatment for penicilliosis
Ambisome 3mg/kg per day for 2 weeks then 10 weeks oral itraconazole 200mg bd po
Do we give primary prophylaxis for penicilliosis?
Itraconazole 200mg OD to travellers to endemic areas with CD4 <100
When should ARVs be started for patients with penicilliosis?
As soon as clinical response noted to treatment
