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Infectious Diseases - Coggle Diagram

- - - - P. falciparum
        
        Most common in Africa
        
        Crescent/banana stage, headphones in RBC
        Affects matur and immature RBCs
        Parasitaemia high
        
        Commonest cause of severe diseases
        
        First line treatment - ACT (artemisinin based combination therapy)
      - P. vivax
        
        Most common outside Africa
        
        Round/oval gametocytes, Schuffner stippling of RBCs
        only infects mature RBCs
        
        First line - oral chloroquine
        Second line - ACT or malarone
        Primaquine to prevent relapses (G6PD can cause haemolysis)
      - P. ovale
        
        Round/oval gametocytes, Schuffner stippling of RBCs
        
        Uncommon, endemic to West Africa
      - P. malariae
        
        Endemic to sub-saharan Africa
        
        Round/oval gametocytes
      - P. knowlesi
        
        Zoonotic malaria from monky macaque reservoir
        
        Round;/oval gametocytes
    - - Protozoan disease transmitted by female Anopheles mosquito, mostly nocturnal biting - bed nets
    - - Clinical (CJABS)
        
        Cerebral malaria
        Jaundice
        Acute respiratory distress
        Abnormal bleeding
        Shock
      - Investigations
        
        Microscopy Giesma stain - gold standard
    - - ACT via IV artesunate
        Combined with doxycycline orclindamycin
      - Prophylaxis
        
        Malarone, doxycycline, mefloquine
  - - - Bite of infected Aedes female mosquito
        Day bighting
        Targets reticuloendothelial system - thrombocytopenia
    - - Febrile phase - decrease in platelet count
        Critical phase - increase in capillary permeability, increasing haematocrite, rapid drop in platelet count
        Recovery phase - gradual reabsorption of extravascular compartment fluid - rash (isles of white in sea of red)
        Saddleback fever
    - - IgM detectable in 1" early on
        IgG higher in 2" infection
  - - - Aedes mosquito
      - Extrinsic incubation 0 time between mosquito blood meal from varaemic host and transmission of virus to new host - warmer temperature has shorter period
      - Intrinsic incubation period time between mosquito refeeding and period of viraemia/symptom onset
    - - Replicates in skin and fibroblasts, disseminates
        Disease onset coincides with rising viral titre - innate immune response - hallmark is production of type I IFNs
        Adaptive immunity after period of viraemia, recovery has viral-specific antibodies
    - - Fever
        joint symptoms
        Pain, tenderness and swelling
        Macular or maculopapular rash
        N&V
    - - Supportive care (paracetamol, NSAIDs)
      - Aspirin not advisable in younger children due to risk of developing Reye's syndrome - rapidly progressing encephalopathy
  - - - Murine typhus
        Exposure to fleas
    - - Scrub typhus
        High grass and bush - rural areas
    - - Tetracycline (doxycycline)
  - - - SPI-1 T3SS (invasion genes) - onset of diarrhoea
      - SPI-2 T3SS (intracellular pathogenesis)
    - - Non-specific features
        
        Patient appears toxic and apathetic
        
        Patient becomes progressively more unwell
    - - Ceftriaxone (3rd gen cephalosporin)
        Ciprofloxacin (chronic carriers)
        Azithromycin
    - - Oral live attenuated salmonella typhi
        IM polysaccharid vaccine
  - - - Direct contact with animal urine or tissues
        Indirect contact with water or soil contaminated with animal's urine
    - - Subclinical infection (common)
        
        Anicteric leptospirosis - self-limiting biphasic disease (90%)
        
        Icteric leptospirosis (Weil's Syndrome) - hepatic and renal failure, jaundice
        
        Severe pulmonary haemorrhage syndrome - frank haemoptysis
    - - Antibiotics - penicillin, doxycycline, ceftriaxone, azithromycin
        Chemoprophylaxis - contraindicated in pregnant women and children
  - - - Trematodes - blood fluke, flat leaf shaped worm
      - Clinical features
        
        Acute
        
        Swimmer's itch - localised pruitic dermatitis
        Katayama fever - systemic hypersensiticity reaction against migrating parasites - serum sickness, lymphadenopathy, hepatosplenomegaly
        
        Chronic
        
        Hepatic schistosomiasis - inflammation with hepatomegaly and splenomegaly
        Urogenital schistosomiasis - chronic inflammation in urinary tract
      - Treatment
        
        Praziquantel
    - - Clinical features
        
        Cysts from trophozoites
        Dysentery, colities - trophozites shed in diarrhoeal stool
        Amoebic liver abscess
      - Treatment
        
        Metronidazole
    - - Nematodes - strongyloides stercoralis
        Faecal-oral transmission
      - Clinical features
        
        Localised pruitis erythematous rash at site of skin penetration
        Chronic - mild peripheral eosinophilia, elevated IgE levels
      - Treatment
        
        Ivermectin
        Albendazole
  - - - Infection
        Bacteremia - bacteria in blood
        Systemic inflammatory response syndrome (SIRS) - severe inflammatory response
        Severe sepsis - associated with organ dysfunction,hypoperfusion, hypotension
        Septic shock - sepsis-induced hypotension despite adequate fluid resuscitation
        Multi-organ disorder - homeostasis not maintained without intervention
        Sepsis induced hypotension (SIH)
        Disseminted intravascular coagulation - uncontrolled thrombosis - consumption coagulopathy - clotting factors and platelets consumed in excess
    - - Antibacterial - Pseudomonas aeruginosa - ceftazidime
        Antivral - HAV/VZV - acyclovir (oseltamivir if pregnant/immunocompromised)
        Antiparasitic - IV antimalarials
  - - - Continuous
        
        Typhoid fever (S. typhi)
        
        Permanently febrile
      - Intermittent/spiking
        
        High spikes and rapid defervescence
        
        Simple Tertian (every 48h) - P. vivax/ovale
        Simple quartan (every 72h) - P. malariaeMalignant tertian - cerebral malaria
        Intermittent fever associated with abscess
      - Recurrent/periodic
        
        Fever that happens multiple times over a period of time
        
        Pel Ebstein fever - Hodgkin's lymphoma - cyclical/long periodicity fever
      - Biphasis
        
        Fever than breaks and returns once more
        
        Saddleback fever - leptospirosis, dengue, legionnaries
  - - - Live virus particles with very low virulence given
      - MMR, BCG, OPV
    - - Virsu particles cultured and killed, but proteins still recognisable
      - IPV
    - - Partial viral peptide administered
      - Influenza
    - - Produced artificially by yeasts
      - HBV
    - - Proteins attached to carrier protein
      - HiB, PCV
    - - toxin produced by pathogens
      - Tetanus, diphtheria
- - - - Aerobic/anaerobic
        Microaerophilic culture - campylobacter
        BCYE - legionella
        Acid fast - Mycobacteria
    - - Streptococcus pneumoniae - pneumoccalurine antigen
        Legionella pneumophilia - legionella urine antigen - serogroup 1
        H. pylori - rapid urease test, urea breath test, stool antigen test
        Neisseria gonorrhoeae - urethral swab PCR
  - - - Mycobacterium
    - - KOH/Calcofluor - chitin and cellulose containing structures - fluoresces with polarised light
        India ink stain -cryptococcus in CSF
        Mucicarmine stain - stains capsule of cryptococcus pink
        Gram stain +ve - candida, cryptococcus
- - - - Otitis media
        
        Streptococcus pneumoniae
      - URTIs
        
        Streptococcus pyogenes
        Haemophilus influenzae
      - Sinusitis
        
        Streptococcus pneumoniae
        Haemophilus influenzae
      - Meningitis
        
        Streptococcus pneumoniae
        Neisseria meningitidis
        Haemophilus influenzae
      - Eye infections
        
        Staphylococcus aureus
        Neisseria gonorrhoeae
        Chlamydia trachomatis
    - - Gastritis
        
        H.pylori
      - Food poisoning (ECCSSS)
        
        E. coli
        Campylobacter jejuni
        Clostridium
        Staph aureus
        Salmonella
        Shigella
    - - UTI (PEES)
        
        Pseudomonas aeruginosa
        E. coli
        Enterobacteriacease
        Staph saprophyticus
      - STD (C-HUNT)
        
        Chlamydia trachomatis
        Haemophilus ducreyi
        Ureaplasma urealyticum
        Neisseria gonorrhoeae
        Treponema pallidum
      - Skin (PSS)
        
        Pseudomonas aeruginosa
        Staph aureus
        Strep pyogenes
    - - Dm Foot Infection - polymicrobial
      - Lemierre's syndrome - fusobacterium
      - Brain abscess - oral anaerobes (Strep viridans)
      - GIT - anaerobes - bacteroides and clostridium
  - - - Gingivostomatitis - oral infection, inflammation
        
        HSV type 1
      - Common cold (PRR)
        
        Parainfluenza
        RSV
        Rhinoviruses
      - Pharyngitis (ACE)
        
        Adenovirus
        CMV
        EBV
      - Parotitis
        
        Mumps virus
      - Eye infections (ACH)
        
        Adenovirus
        CMV
        HSV
    - - Gastroenteritis
        
        Coronavirus
        Adenovirus
        Rotavirus
        Astrovirus
        Norovirus
      - Cardiovascular/Pancreatitis
        
        Coxsackie B virus
      - Hepatitis
      - Pneumonia (SIPRA)
        
        SARs coronavirus
        Influenza
        RSV
        Adenovirus
    - - VZV
        Oarvivirus B19
        Rubella
        HHV6
        Measles
        Smallpox
        HPV
    - - HPV
        HIV
        HSV2
- - - - 1" pulmonary TB infection
        
        Immunocompetent
        
        Asymptomatic, results in healed lesions - subpleural focus and a draining lymph node
        Large mediastinal/hilar lymph nodes with inconspicuous pneumonitis in lower/middle lung field
        
        Immunocompromised
        
        New infection leads to progressive primary TB
      - 2" (reactivation) pulmonary TB
        
        Arises in previously exposed individuals when host immune defences are compromised
        
        Classically localised to apex of upper lobes
        Regional lymph nodes less prominently involved early in the disease that 1"
    - - Transmission
        Primary lesion (ghon focus) - gray-white inflammatory consolidation
        Spread of TB infection - Ghon complex - caseous necrosis of centre of Ghon focus, lymphadenopathy
        ~ Ranke complex - when Ghon complex undergoes fibrosis and calcification
        Progression to overt pulmonary TB disease (from occult TB - more lymphocytes and monocytes migrate to site of infection)
        Microbial inhibition by the body
    - - Special type of chronic inflammation - hallmark of host reaction to TB in immunocompetent individuals
        
        Epithelioid hisiocytes (activated macrophages), giant cell, necrosis in the middle
        
        Complication - ceasation (cheeselike, hallmark of TB infection
        Cavitation - strong delayed-type hypersensitivity to bacilus
      - Extrapulmonary manifestations
        
        Miliary TB - small nodular lesions resembling millet seeds
        
        TB meningitis - focal neurological deficit
        
        Spinal TB (Pott's disease) - discitis (inflammation between intervertebral discs of spine), spreads to vertebral bodies. compress spinal cord
    - - Vaccine - BCG - Live attenuated vaccine created from Mycobacterium bovis
      - Isoniazid - used to treat latent TB infection to prevent reactivation (6 months)
      - Rifampicin + isoniazid (3 months) - may be more toxic - 2nd line
      - First line treatment - RIPE
        
        Rifampicin
        
        Orange coloured urine, hepatitis
        
        Isoniazid
        
        Peripheral neuropathy (prevent with pyridoxine), hepatotoxicity (fulminant liver failure rarely)
        
        Pyrazinamide
        
        Hyperuricemia - gout, hepatitis
        
        Ethambutol
        
        Optic neuritis
    - - HIV resistance with rifampicin use - use rifabutin instead
      - Antiretrovirals could cause paradoxical immune response and sever inflammatory reaction but must still be used
  - - - Chronic bronchopulmonary disease (in patients with cystic fibrosis)
        Lymphadenitis (children) - MAC
        Skin and soft tissue manifestations, skeletal infections
        Catheter-related infections
        Disseinated disease (immunocompromised)
    - - Adenopathy, thickening of bowel mucosa, poorly formed abscesses and granulomas
        Anemia
      - Treat with combination therapy - macrolide (erythromycin) + rifamycin (rifampicin) + ethambutol
- - - - Streptococcus pneumoniae (gram +ve cocci)
        Haemophilus influenzae (gram -ve coccobacilus)
        Moraxella catarrhalis (gram -ve diplococci)
      - Diffuse patchy changes, non-productive cough, normal WBC count
      - Need to treat with specific antibiotics - macrolides
        Aminopenicillin first line
    - - Mycoplasma pneumoniae
        Chlamydia pneumoniae
        Legionella pneumoniae
      - Lobar consolidations, productive cough, leukocytosis
      - Covered by standard penicillin antibiotics
    - - Parapneumonic
        
        Uncomplicated - fluid accumulates in pleiral spaces
        Complicated - flid accumulated is acidic
        Empyema - Streptococcus spp., anaerobes, staph aureus
      - Pulmonary abscess
  - - - Influenza, respiratory synctial virus (RSV), adenovirus
    - - H5N1 - Avian flu
        H1N1 - Swine flu
    - - Viral nuclei acid test - current infection
      - Serologic - past infection
      - Treat with dexamethazone, remdesivir (viral RNA polymerase inhibitor)