Infectious Disease and STI Flashcards
(118 cards)
How does Toxoplasmosis present ?
Similar to IM
Cervical Lymphadenopathy
Single or Multiple Ring Enhancing Lesions on CT in HIV patients
Management for Toxoplasmosis
No Treatment if Immunocompetent
Pyrimethamine plus sulphadiazine for 6 weeks if HIV/Immunocompromised
Congenital Toxoplasmosis Features
Neuro
Hydrocephalus
Chorioretinitis
Cerebral Calcifications
Opthalmo
Cataracts and Retinopathy
Leprosy Treatment ?
If >/=6 Multibacillary
1. Extensive Skin
2. Involvement
Symmetrical Nerve Involvement
If </=5 Paucibacillary
(Tuberculoid Leprosy)
1. Limited Skin Involvement
2. Asymmetrical Nerve –> Hypersthesia
3. Hair Loss
Treatment of Leprosy ?
If Multibacillary then give Rifampicin, Dapsone, Clofazimine for at least 2 years
If Paucibacillary then Rifampicin, Dapsone for 6 months
Animal Bites Causative Pathogen and Treatment
Pasteurella Multocida
Treatment - Co-Amoxiclax (doxycycline + metronidazole ) and Don’t Suture them unless Cosmetic Reasons
Human Bites Causative Agent and Treatment
Streptococci spp.
Staphylococcus aureus
Eikenella
Fusobacterium
Prevotella
Co-Amoxiclav
Non Specific Urethritis Treatment and Causative Agents
Only inflammatory cells seen in Discharge no GN Cocci (Gonorrhea) or Chlamydia
Check Gonorrhoeic and Chlamydia NAAT within 2 week window usually and Retest if NEG BUT COVER in the mean time WITH …..
Doxycycline or Azithromycin
Malaria Life Cycle Explain
Sporozytes injected into Blood Circulation
Sporozytes infect hepatocytes –> reproduce asexually —> merozoites —> schizont merozoites
If P.Vivax or P.Ovale —> Reside in Hepatocytes –> Hypnozoites
Schizont Merozoites burst —> enter blood circulation —> infect RBC to become Trophozoites (Early - Signet Ring Cell)
Trophozoite Burst Releasing Merozoites and the cycle continues
After several Asexual cycles —> Merozoites –> Gametocytes —> Taken up by mosquito –> Gametocytes fuse into Oocyte –> Oocyte Burst and go to Mosquito salivary glands –> Cycle Repeats
P.Malariea - Every 72 hours
P.Falciparum P.O/P.V –> 48 hrs
Malaria Treatment
If Uncomplicated Falciparum —> ACT (Free Radical Mediated)
Chloroquine Resistant —> Quinine OR Atovaquone + Proguanil
If Non Falciparum –> ACT or Chloroquine
Complicated Malaria –> IV Artesunate (Hemolysis) or IV Quinine (Hypoglycemia)
Hypnozoites –> Primaquine
If Parasetemia > 10% then Exchange Transfusion
Most Common Cause of Non Falciparum Malaria ?
Vivax
Aspergilloma Feature on CXR ?
Crescent Sign
If Thick and Thin Film Negative first time What to do Now ?
Start Chemoprophylaxis –> Repeat daily for 2 days –> Unlikely but finish prophylaxis
PCR only 1 week after infection
When to Start Treatment in Viral Meningitis vs Viral Encephalitis ?
Viral Meningitis –> No need to start
Viral Encephalitis (Drop in GCS / Motor or Speech / Altered Behavior) –> IV Acyclovir
Leptospirosis Treatment
- High Risk Occupation
- Features
- Investigations
- Sewage Workers, Farmers (Rat Urine), Vets or People who work in slaughter Houses / Abattoirs OR WATER SPORT ENTHUSIAST
2.
Phase 1
Subconjunctival Suffusion / Haemorrage
Phase 2
Aseptic Meningism
Severe
Hepatorenal (Weils)
- IgM at the end of 7 days post infection
Blood CSF Cultures Positive in 10 days
Urine 14 days - Mild / Moderate - Doxy or Azithromycin
Severe - IV Ben Pen
Which Pathogen works via Endotoxin ?
Neisseria Meningitis
Exotoxins Types and MOA
Read Note and Memorize
TB investigations
So Mantoux first line.
If positive- suggests TB or BCG vaccine.
If negative - no exp to TB or no vaccine history.
If positive then Interferon Gamma to distinguish between TB and BCG
If positive then pt has been exposed to TB.
If negative then pt has had the BCG vaccine.
If mantoux negative but at risk of a false neg result then Interferon Gamma, again if negative no exposure to TB
When will Mantoux Test be Risk of False Negative ? Hence when should we doing IGRA
False negative tests may be caused by:
miliary TB
sarcoidosis
HIV
lymphoma
very young age (e.g. < 6 months)
TB Smear (ZN and Fluorescent) Vs Culture (Gold Standard)
By Ziehl-Neelsen stain
Fix the smear –> stain with carbol-fuchsin (pink dye) –> decolourise with acid-alcohol –> counterstain with methylene blue
Acid fast bacilli appear pink (Resistant to decolouration by acid, can retain dye)
Fluorescent staining
Auramine-phenol stain –> 15 mins –> wash with acid-alcohol –> counterstain with thiazine red
Observe under fluorescent microscope –> see fluorescent bright greenish yellow in a dark background
For Culture what’s the Solid Culture Called?
Solid: Lowenstein-Jensen
We do PCR looking for MTB and Rifampicin Resistance (rpoB Gene)
Campylobacter Antibiotic of Choice
Clarithromycin
Trypanosomiasis
- Types and Pathogens
- Features
- Treatment
American in Next Slide
African -
East African (T.Rhoedensi)
More Acute
1. Trypanosoma chancre - 2. Intermittent fever
3. enlargement of posterior cervical lymph nodes
later: CNS involvement
West African (T.Gambeinse)
Treatment for AFRCIAN
Early : IV pentamidine or suramin
Late or central nervous system involvement: IV melarsoprol
American Trypanosomiasis (Chaga’s)
Trypsonama Cruzi
Acutely (90% asymptomatic) but Chagoma (Erythematous Nodule) + Periorbital Swelling Seen (Romana Sign)
Later
Myocarditis –> Dilated Cardiomyopathy
Megaesophagus and Megacolon
Treatment
Acute benznidazole or nifurtimox
Chronic - Treat Complications