ID Flashcards
What are the two types of trypanosomiasis
African (sleeping sickness)
American (Chagas’)
Clinical features of African trypanosomiasis
Trypanosoma chancre - painless subcut nodule at site of infection
Intermittent fever
Enlargement of posterior cervical lymph nodes
Later - cns involvement - somnolence, headaches, mood changes, meningoencephalitis
Management of African trypanosomiasis
Early - IV pentamidine or suramin
Later (or cns involvement) - IV melarsoprol
Features of American trypanosomiasis
Asymptomatic in acute phase
Chagoma - erythematous nodule at site of infection
Myocarditis and arrhythmias later
GI features - megaoesophagus & megacolon causing dysphagia & constipation
Management of American trypanosomiasis
Most effective in acute phase - benznidazole or nifurtimox
Chronic management is managing complications eg hf
Most common non-falciparum malaria
Plasmodium vivax
Where are the non-falciparums from?
Vivax - Central America and Indian subcontinent
Ovale - Africa
Knowlesi- Southeast Asia
Features of the non-falciparums
General malaria - fever, headache, splenomegaly
Vivax/Ovale - cyclical fever every 48hrs
Malariae - cyclical fever every 72hr & associated with nephrotic syndrome
Treatment of the non-falciparums
ACT - avoid in pregnancy
Chloroquine- not if resistant area
Ovale or vivax should be given primaquine
Factors which reduce vertical transmission of HIV in pregnancy
Maternal antiretroviral therapy
Mode of delivery (caesarean)
Neonatal antiretroviral therapy
Infant feeding (bottle feeding)
Where is brucellosis common
Middle East and farmers, vets & abattoir workers
What are the four species that cause brucellosis
B melitensis (sheep)
B abortus (cattle)
B canis & B suis (pigs)
What is the brucellosis incubation period
2-6 weeks
Features of brucellosis
Fever, malaise
Hepatosplenomegaly
Sacroiliitis
Complications - osteomyelitis, infective endocarditis, meningoencephalitis, orchitis
Leukopenia often seen
Diagnosing brucellosis
Rose Bengal Plate test for screening
Brucella serology best option
Management of brucellosis
Doxy and streptomycin
Features of mycoplasma pneumoniae
Prolonged and gradual onset
Flu like symptoms before dry cough
Bilateral consolidation on cxr
Complications of mycoplasma pneumonia
Cold agglutinatins (IgM) may cause an haemolytic anaemia, thrombocytopenia
Erythema multiforme, erythema nodosum
Meningoencephalitis, guillain barre
Bullous myringitis
Pericarditis/myocarditis
Hepatitis/pancreatitis
Acute glomerulonephritis
Management of mycoplasma pneumonia
Doxy or a macrolide (erythromycin/clarithromycin)
Aetiology of dengue fever
RNA virus
Transmitted by Aedes aegypti mosquito
Incubation 7 days
Features of dengue fever
Fever
Headache (often retro-orbital)
Myalgia, bone pain, arthralgia
Pleuritic pain
Facial flushing
Maculopapular rash
Haemorrhagic manifestations - petechiae, pupura/ecchymosis, epistaxis
Warning signs - abdo pain, hepatomegaly, persistent vomiting, clinical fluid accumulation
Features of severe dengue
Form of DIC - thrombocytopenia & spontaneous bleeding
Around 20-30% develop dengue shock syndrome
Dengue investigations
Bloods - leukopenia, thrombocytopenia, raised aminoytansferases
Diagnostics - serology, NS1 antigen test, test for viral RNA
Treatment of Dengue
Fluid resus
Blood transfusions
All symptomatic
What causes Lyme disease
Borrelia burgdorferi
Spread by ticks
Early features of Lyme disease
Erythema migrans - -
Bullseye rash at site of bite
Typically 1-4 week after bite
Painless bite
Systemic - headache, lethargy, fever, arthralgia
Late features of Lyme disease
Heart block
Peri/myocarditis
Facial nerve palsy
Radicular pain
Meningitis
Investigating Lyme disease
Clinically if can see erythema migrans
ELISA - look for antibodies to borrelia burgdorferi
Management of Lymes
Doxy (not if pregnant)
Amox second line
Ceftriaxone if disseminated disease
What’s the Jarisch-Herxheimer reaction
Acute febrile reaction that occurs within first 24hr of initiating treatment for spirochetal infections
Fever, chills, headache, myalgia and exacerbations of skin lesions
How is Japanese encephalitis spread
Via culex mosquitos which breed in rice paddy fields
Common in south east Asia, China, India and the western pacific
Clinical features of Japanese encephalitis
Mostly asymptomatic
Headache, fever, seizures and confusion
Parkinsonian features indicate basal ganglia involvement
Acute flaccid paralysis
What is aspergilloma
A mycetoma (mass-like fungus ball) which often colonises and existing lung cavity (secondary to TB, lung cancer or cystic fibrosis)
Features of aspergilloma
Asymptomatic
Cough
Haemoptysis
Investigations of aspergilloma
Cxr - rounded opacity, crescent sign may be present
High titres aspergillus precipitins
Where does one contract legionella
Colonises water tanks - air conditioning systems etc
Legionella features
Flu-like symptoms
Dry cough
Relative bradycardia
Confusion
Lymphopenia
Hyponatremia
Deranged LFT’s
Pleural effusion - around 30% of patients
Investigations for legionella
Urinary antigen
Cxr - non specific but may have mid to lower zone predominant patchy consolidation & pleural effusion
Management of legionella
Erythromycin or clarithromycin
Which vaccines are live
BCG
MMR
Influenza
Oral rotavirus
Ora polio
Yellow fever
Oral typhoid
