Infectious Diseases Flashcards
Strongyloides stercoralis
Pathophysiology?
Acute infection (skin, pulmonary, GI)?
Diagnosis?
Treatment?
human parasitic nematode worm found in soil and infects via the skin
Skin -> larva currens. Pulmonary -> Loeffler’s syndrome (transient pulmonary infiltrates, cough). GI -> Abdominal pain, diarrhea, or constipation
Stool microscopy (Larvae)
Ivermectin
What medication is indicated in non-falciparum malaria to destroy liver hypnozoites and prevent relapse
Primaquine
Gastroenteritis in student who is eating rewarmed rice causative agent?
Bacillus Cereus
If CD4 count is less than? life long prophylaxis is needed against toxoplasmosis?
<200
Toxoplasmosis
Causative agent?
Diagnosis?
Tx?
Toxoplasma gondii
Serology
Pyrimethamine + Sulfadiazine + folinic acid Immunocompromised)
If fit and well - no Tx required
What is the mechanism of integrase inhibitors (‘Gravirs’)
blocks the enzyme that inserts the viral genome into the DNA of the host cell
Mechanism of HIV drugs maraviroc and enfuvirtide?
Bind to coreceptors necessary for HIV entrance into CD4+ cells
MOI of Non-nucleoside reverse transcriptase inhibitors (NNRTIs) (e.g. nevirapine, efavirenz)
Block HIV reverse transcriptase thereby preventing the HIV virion from replicating
MOI Nucleoside analogue reverse transcriptase inhibitors (NRTIs) (e.g. zidovudine (AZT), abacavir, emtricitabine, lamivudine, and tenofovir)
Inhibit reverse transcription by being incorporated into the growing viral DNA strand and preventing further addition of nucleotides
MOI antiretroviral inhibitors HIV drug class (indinavir, nelfinavir, and ritonavir)
Binding to the catalytic site of the HIV protease, thereby preventing the cleavage of viral polyprotein precursors into mature, functional proteins
Teenager swam in lake in asia. suffered self resolving itchy rash on legs. now has dysuria and frank haematuria. Eosinophilia on bloods.
Diagnosis?
Tx?
schistosoma haematobium (schistosomiasis/bilharzia)
praziquantel
Hyposplenism or post splenectomy when should patient receive doses?
-pneumococcal, Haemophilus type B and meningococcus type C
- influenza vaccine
-Meningitis ACWY + Further hepatitis B
-14 days post splenectomy
-Every winter/autumn
-2 months post splenectomy
normal vaginal pH (above 4.5), the presence of clue cells on microscopy and/or a positive whiff tes
Bacterial vaginosis - overgrowth of predominately Gardnerella vaginalis
Disseminated gonococcal infection triad
tenosynovitis, migratory polyarthritis, dermatitis
Features
vaginal discharge: offensive, yellow/green, frothy
vulvovaginitis
strawberry cervix
pH > 4.5
in men is usually asymptomatic but may cause urethritis
Investigation
microscopy of a wet mount shows motile trophozoites
Trichomonas vaginalis
Treatment of immunocompromised patients with cryptosporidiosis
Nitazoxanide
deep, painful genital ulcer and is often associated with inguinal lymphadenopathy in sexually active man
Chancroid
High fevers, pharyngitis, dyspnoea, cough, and a grey pseudomembrane covering the tonsils are typical signs and symptoms of
Diphtheria
flu like illness → brief remission→ followed by jaundice and haematemesis in returned fever from tropics?
Yellow Fever
Cryptosporidium can be diagnosed by modified Ziehl-Neelsen staining of stool to reveal
Red Cysts
Bloody Diarrhoea (Campylobacter) tx?
Macrolide
Bloody diarrhoea (Amoebiasis ) Tx?
Metro + diloxanide furoate
Bloody diarrhoea (Salmonella ) Tx?
Ciprofloxacilin
Bloody diarrhoea (Shigella ) Tx?
ciprofloxacin
Bloody diarrhoea E.Haemorrhagic E coli Tx?
Supportive
staphylococci + streptococci (including enterococci)
Gram Positive or gram negative cocci?
Gram positive Cocci
Infection with Schistosoma haematobium is most strongly associated with what cancer?
Squamous cell bladder cancer
ChlamydiaTx
1st line?
2nd Line?
1)Doxycycline
2) Azithromycin
Gonorrhoea Tx
1st line?
2nd line?
1) IM Ceftriaxone
2) Ciprofloxacilin
Lymphogranuloma venereum (LGV)
-Causative agent?
-Primary stage?
-Secondary stage?
-First line treatment?
-Chlamydia trachomatis
-Painless genital ulcer which heals
-Painful lymphadenopathy
-Doxycycline
Chancroid
-Causative bacterium?
-Ulcer?
-Lymphadenopathy?
-Appearance on gram stain?
-Culture media?
-Tx?
-Haemophilus ducreyi
-Painful, ragged edges
-Painful
-‘School of fish’
-Chocolate agar
-Azithromycin
Syphilis
-Organism?
-Primary?
-Secondary?
-Latent?
-Tx?
-Treponema pallidum
-Painless indurated genital ulcer + painless lymphadenopathy
-Generalised maculopapular rash
-Asymptomatic serologically positive
-Benzathine penicillin
MOA of aciclovir?
Inhibition of viral DNA Polymerase
Bacterium responsible for Cat Scratch Disease?
Bartonella henselae
Bacterium responsible for whooping cough?
Bordetella pertussis
MOA of tetanus toxin?
blocks the release of the inhibitory neurotransmitters GABA and glycine resulting in continuous motor neuron activity
What organism can present with culture negative endocarditis?
Coxiella burnetii
MOA: inhibit the enzyme squalene epoxidase, which results in inhibition of ergosterol synthesis required for several fungal cells progresses
-Leads to cellular death and deranged lfts with abdominal pain
Terbinafine
What would the glucose CSF content be in mumps induced encephalitis?
Low
Fever and the presence of a eschar in a patient returning from South East Asia is strongly suggestive of ? and treated with ?
scrub typhus (caused by Orientia tsutsugamushi)
Doxycycline
Why does malaria caused by P. knowlesi lead to the highest parasite count?
shortest erythrocytic replication cycle
MOA Macrolides
inhibit the 50S subunit of ribosomes, inhibiting translocation
Post Exposure HIV prophylaxis PEP regime?
Three drug antiretroviral regime for one month
A butcher, with no travel Hx, presents with acute diarrhoea illness and mesenteric adenitis confirmed on CT. What is the causative agent?
Yersinia enterocolitica infection
