Infectious Disease Flashcards
Name a few Gram (+)ve & (-)ve cocci
Gram (+): Staphylococci & Strepto (including Enterococcus)
Gram (-):
- N meningitidis
- N gonorrhoea
- M catarrhalis
Gram (+)ve rods ??
ABCD-L
- Actinomyces
- Bacillus anthracis
- Clostridium
- Diphtheria
- Listeria monocytogenous
Gram (-)ve rods ??
E coli
H influenzae
P aeruginosa
Salmonella species
Shigella species
C jejuni
Difference b/w Endotoxins & Exotoxins ??
Exotoxins:
- SECRETED by the bacteria
- Generally released by Gram (+)ve bacteria (except V Cholera & some strains of E coli)
ENDOTOXINS :
- Only released after the LYSIS of cels
Types of toxins ??
Classified by their Primary effect
- Pyogenic toxin
- Enterotoxins
- Neurotoxins
- Tissu Invasive toxins
- Miscellaneous toxins
Features of Pyogenic Toxins ??
Stimulates release of Endogenous Cytokines => Fever, Rash
- They are SUPER-ANTIGENS which bridge MHC Class 2 on APCs with T-cell receptors on T cell surface => Massive Cytokine release
Staph. Aureus
- TSST-1
- High fever, Hypotension, Exfoliative rash
Strept. pyogenous
- Strept. pyogenic exotoxin A & C
- Scarlet fever
Features of Neurotoxins ??
Act on Nerve (Tetanus) of NMJ (Botulism) => Paralysis
C TETANI
- Tetanospasmin
- (-) GABA & Glycine release from Renshaw cells of S Cord => Continuous Motor neuron activity => Spastic Paralysis
C BOTULISM (Canned food & Honey)
- B toxin
- (-) ACh release => Flaccid paralysis
Features of Tissue Invasive Toxins ??
C PERFRINGENS
- Alpha-toxin (Lecithinase)
- Gas gangrene (Myonecrosis) & Haemolysis
- Tender, edematous skin + Bloody Blebs & Bullae +/- Crepitus
STAPH. AUREUS
- Exfoliatin
- Staph. Scalded Skin Syndrome
Features of Staphylococci ??
Normal commensal organism
- Gram (+)ve cocci
- Facultative Anaerobes
- CATALASE (+)ve
2 TYPES
Staph. aureus
- Coagulase (+)ve. - Cellulitis, Abscesses, Osteomyelitis, TSS
Staph. Epidermidis
- Coagulase (-)ve
- Central Line Infection & Infective Endocarditis
Features of Staph. TSS ??
Severe systemic reaction to Staph. EXOTOXINS- TSST-1 Superantigen
- Infected Tampons
Dx. Criteria
- Fever > 38.9 C. - SBP < 90mmHg
- Diffuse Erythematous rash
- Desquamation of Palms & Soles
- >= 3 organs involved
Rx.-
- Remove Infection Focus
- IV Fluids. - IV Antibiotics
Hallmark of MRSA ??
All pts. waiting for Elective admission & All emergency admissions Must be screened for MRSA
- Nasal swab & Skin lesion or Wounds
- Swab wiped around the rim of pts. nose for 5 sec.
How to treat MRSA carriers ??
NOSE : Mupirocin 2% in white paraffin, TDS for 5 days
SKIN: Chlorhexidine Gluconate OD for 5 days
- Apply all over but particularly to Axilla, Groin & Perineum
Rx. of MRSA infection ??
MC used Antibiotics are
- Vancomycin / Teicoplanin / Linezolid
The following even though found sensitive should not be used due to devt. of Resistance
- Rifampicin. - Tetracyclines
- Aminoglycosides. - Clindamycin
Linezolid, Quinupristin/Dalfopristin & Tigecycline are reserved for Resistant cases
Features of Streptococci ??
Gram (+)ve cocci; Classified based on Haemolysis pattern
ALPHA (Partial H, Green)
- Viridans Streptococci (No capsule) eg.- S mutans, S mitis & is (-)ve for Optochin sensitivity & Bile solubility
- S pneumonia (Encapsulated) is (+)ve for Optochin & Bile solubility
BETA (Complete Haemolysis, Clear)
- Grp. A (S pyogenes) is (+)ve for Bacitracin sensitivity & PYR status
- Grp. B (S agalactiae) is (-) for Bacitracin & PYR status
GAMMA (No Haemolysis, grows is Bile
- Nonenterococcus (S gallolyticus) is (-)ve for PYR status & Growth in 6.5% NaCl
- Enterococcus (E faecium, E faecalis) is (+)ve for the above 2 tests
Group A & B Streptococci ??
Grp. A
- Most imp. organism is S pyogenes
- Causes Erysipelas, Impetigo, Cellulitis, Type 2 Nec. Fasciitis, Pharyngitis & Tonsillitis
- Immune reaction can cause Rheumatic Fever or PSGN
- Erythrogenic toxin: SCARLET Fever
Grp. B
- S agalctiae
- NEONATAL Meningitidis & Septicaemia
Name the Organisms a/w the following virulence factor
- IgA Protease
- M Protein
- Polyribosyl ribitol phosphate capsule
- Bacteriophage
Virulence factors colonize the host & evade/ suppress the immunity
- Strep. Pneumonia, H influenzae, N gonorrhoea
- Strep. pyogenes
- H influenzae
- C diptheriae
Name the Organisms a/w the following virulence factor
- Spore formation
- Lecithinase Alpha Toxin
- D-Glutamate Polypeptide Capsule
- Actin Rockets
- B anthracis, C perfringens, C tetani
- C perfringens
- B anthracis
- Listeria monocytogenes
Hallmark of Cellulitis
Inflammation of Skin & Subcutaneous tissue due to Strep. pyogenes or Staph. aureus infection
- Site: Shins
- Erythema, Pain, Swelling
- Systemic upset- Fever
Clinical Dx; Bloods & Blood cultures needed if Admitted & Septicaemia is suspected
Criteria for admission in Cellulitis ??
Eron Classification
CLASS 1 :
- No signs of systemic toxicity
- No uncontrolled Co-morbidities
CLASS 2:
- Systemically Unwell/ Well but has Co-morbidity (PAD, Morbid Obesity, Chr. Venous Insufficiency); can complicate/ delay infection resolution
CLASS 3:
- Significant Systemic upset (OR)
- Unstable Co-morbidity that may interfere with Rx. response (OR)
- Limb threatening infection due to Vascular comprise
CLASS 4:
- Sepsis syndrome (OR) Severe life threatening infection (Nec. Fasciitis)
When should we admit pt. for IV Antibiotics ??
- Eron Class 3 or 4
- Severe rapid deteriorating Cellulitis
- Very Young (< 1yr) or Frail
- Immunocompromised
- Significant Lymphoedema
- Facial Cellulitis (unless very mild) or Periorbital Cellulitis
How is Eron Class 2 cellulitis managed ??
Admission not necessary if
- Facilities & Expertise are available in the community to give IV Abx. & monitor the patient
Other pts., can be treated with Oral Abx.
DoC for Cellulitis ??
1st line: FLUCLOXACILLIN (Mild to moderate)
- Clarithromycin, Erythromycin (in Pregnancy) or Doxycycline is used in pts. allergic to Penicillin
Severe Cellulitis
- Co-Amoxiclav. - Cefuroxime
- Clindamycin. - Ceftraixone
Hallmarks of Nec. Fasciitis ??
Medical emergency; 2 types
TYPE 1 (MC type)
- Mixed anaerobe & Aerobes
- MC Post-Sx in Diabetics
TYPE 2 - Strepto. Pyogenes
RFs
- Skin trauma, Burns, Soft tissue infection
- IV Drug use. - Immunosuppresion
- DM (especially if Pt. is on SGLT-2 i)
Features & Rx. of Nec. Fasciitis ??
Acute onset; Pain, Swelling, Erythema
- Rapidly worsening cellulitis with pain out-of-keeping with findings
- Extremely Tender + Hypoasethesia to light touch
Late signs
- Skin necrosis, Crepitus/Gas gangrene
- Fever & Tachycardia
TREATMENT
- Urgent Surgical Referral for Debridement & IV Antibiotics
Hallmark of Acute Epiglottitis ??
H influenzae type B infection
- Now more common in Adults
- Rapid Onset, Stridor, High Temp.
- Generally unwell, Drooling of saliva
- Tripod Position (leaning forward, Extending neck, seated position)
Dx. of Acute Epiglottitis ??
Direct visualization (by senior)
X-ray (concern of Foreign body)
- Lateral view: Thumb sign
- PA view in CROUP: Subglottic narrowing called Steeple sign
Rx. of Acute Epiglottitis
Immediate Senior involvement + Anaesthetics/ ENT for Intubation
- Endotracheal Intubation
If suspected, DO NOT examine the throat => risk of Obstruction
O2
IV Antibiotics
Hallmarks of Scarlet fever ??
Is a REACTION to Erythrogenic toxins produced by Grp. A Streptococci (Strept. pyogenes)
- MC in 2- 6 yrs old & peaks at 4 yrs
Dx.- Throat Swab (Abx. started immediately & do NOT wait for results)
Features of Scarlet Fever ??
Incubation in 2- 4 days
- Fever: lasts for 24- 48 hrs
- Malaise, Headache, N & V
- Sore throat. - ‘STRAWBERRY’ tongue
- Rash: Fine, punctate erythema (pinhead)
Rx
- Oral Penicillin V * 10 days
- Azithromycin (if Penicillin allergic)
- Can return to School 24hrs after starting Abx.
- NOTIFIABLE Disease
Feature of Scarlet fever RASH ??
Fine punctate erythema (pinhead)
- Torso ==> rest of body
- Palms & Soles spared
- Flushed appearance + Circumoral pallor
- More obvious at Flexures
- Rough Sandpaper texture
- Desquamation occurs later; particularly of Fingers & Toes
Complications of Scarlet Fever ??
MC is OTITIS MEDIA
- Rheumatic Fever (occurs 20 days after infection
- Acute GN : 10 days after infection
- Invasive complications: Bacteraemia, Meningitis, Fasciitis are rare BUT is life threatening
Hallmarks of Croup ??
URTI (Larynx, Trachea, Bronchial tubes); MC- Infants & Toddlers (peaks at 6 months- 3 yrs);
MC during Autumn
MCC: PARAINFLUENZAE Virus
C/F
- Fever +Stridor + Barking Cough (worse at Night) + Coryza
Grading of Croup ??
MILD
- Occasional Barking Cough
- No audible Stridor at Rest
- No/Mild Suprasternal &/or Intercostal recession
- Child happy + Playful + Eats
MODERATE
- Frequent Barking Cough
- Stridor at Rest
- Suprasternal & Sternal wall Retraction at Rest
- No/Little distress or Agitation
- Child can be placated + Interested in surrounding
SEVERE
Severe features of Croup ??
- Frequent Barking Cough
- Prominent INSPIRATORY (& occasional Expiratory) Stridor at Rest
- Marked Sternal wall Retraction
- Significant distress & Agitation or Lethargy or Restlessness (sign of HYPOXAEMIA)
- Tachycardia (due to more severe obstruction symptoms & Hypoxaemia
When should a child with moderate or severe croup be admitted ??
- < 6 months of age
- Known Upper Airway abnormalities (Laryngomalacia, Down’s)
- Uncertain about Dx.
Ix. done in Croup ??
Dx. CLINICALLY
CXR is done
- PA view: Subglottic narrowing called ‘Steeple Sign’
- Lateral view in A Epiglottitis: Swelling of Epiglottis- Thumb sign
Rx. of Croup ??
Single dose DEXAMETHASONE (0.15mg/kg) to ALL kids regardless of severity
- Prednisolone is an alternative
A&E Rx
- High flow O2
- Nebulised Adrenaline
Mention the MCC of meningitis in
- 0- 3 months old ??
- 3 months - 6 yrs old ??
- Grp. B Strept. (MCC in Neonates)
- E coli.
- L Monocytogenes
- N Meningitidis
- Strep. Pneumoniae.
- H Influenzae
Mention the MCC of meningitis in
- 6 yrs - 60yrs old ??
- > 60 yrs old ??
- Immunocompromised ??
- N Meningitidis
- Strep. Pneumoniae.
- Strep. Pneumonia
- N Meningitidis
- L Monocytogenes
L Monocytogenes
Which viral meningitis is a/w low glucose level in CSF ??
MUMPS Encephalitis»_space;>
Herpes Encephalitis
In which conditions are LP contraindicated ??
Rx. of Choice in Meningitis if Penicillins are CI ??
Raised ICP
CHLORAMPHENICOL
Initial Empirical Rx of Meningitis ??
- Aged < 3 months: IV Cefotaxime + Amoxicillin (or Ampicillin)
- 3 months- 50 yrs: IV Cefotaxime (or Ceftrixone)
- > 50yrs old : IV Cefotaxime (or Ceftriaxone) + Amoxicillin (or Ampicillin)
IV Dexamethasone is also given to reduce the risk of CNS sequelae
Drug of Choice for the following causes of Meningitis-
- Meningococal M ??
- Pneumococcal M ??
- H Influenzae ??
- L Monocytogenes ??
- IV BZPs or Cefotaxime (or Ceftriaxone)
- IV Cefotaxime (or Ceftriaxone)
- IV Cefotaxime (or Ceftriaxone)
- IV Amoxicillin (or Ampicillin) + Gentamycin
Conditions where IV Dexamethasone is withheld in the Rx. of Meningitis ??
- Septic Shock
- Meningococcal Septicaemia
- Immunocompromised
- Meningitis after Surgery
Prophylaxis in Meningitis ??
Offered to Households & Close contacts of pt. with Meningococcal M
- Also be given if exposed to Resp. Secretions REGARDLESS of Closeness
- Exposed to pts. with CONFIRMED case of Bacterial Meningitis within past 7 days
Risk is highest in first 7 days but persists for at least 4 weeks
Drug of Choice for Prophylaxis of
- Meningococcal Meningitis ??
- Pneumococcal Meningitis ??
Ciprofloxacin»_space;> Rifampicin
- Meningococcal Vaccine is offered once the Serotype results are available
No Prophylaxis for Pneumococcal M
- If cluster of cases occur, HPA have a protocol for offering colse contacts Abx. Prophylaxis
Hallmark Features of Viral Meningitis ??
MC cause of Meningitis
Meningitis is the inflammation of Leptomeninges & CSF at Subarachnoid space
- Viral M is more benign than Bacterial M
CAUSES
- Mumps. - HIV. - Measles
- Non-Polio Enterovirus: Coxsackie virus, Echovirus
- HSV. - CMV. - Herpes Zoster
Clinical Features of Viral Meningitis ??
MC among < 5 yrs & Elderly, Immunocompromised, IVDU
- Headache, Neck stiffness, Confusion
- Photophobia (Milder than in Bacterial)
- Fever
CSF : Lymphocyte predominant (15- 1000 cells/mm3) increased cell count with normal/ raised glucose & protein levels
Normal CSF finding values ??
Opening Pressure: 10- 20 cmH2O
Cell Count : 0- 5 cells/uL
Cell Differential : 0- 5 cells/uL, Lymphocyte
Glucose : 2.8- 4.2 mmol/L or 2/3rd of Serum Glucose levels)
Protein : 0.15- 0.45 g/L
Rx. of Viral Meningitis ??
While waiting for LP results, Supportive Rx is started
- Self limiting, symptoms resolve by 7- 14 days & complications are rare in Immunocompetent
- If Bacterial M or Encephalitis suspected, IV Broad Spectrum Abx. is started
Viral Meningitis by which organism needs Anti-viral Rx. ??
Meningitis secondary to HSV
- IV Aciclovir
Hallmark of Meningococcal Septicaemia ??
a/w High morbidity & mortality unless treated early
- It is the leading infectious cause of death in EARLY Childhood
Presentations
- 15% - Meningitis
- 25% - Septicaemia
- 60% - Combination of the above 2
Ix.-
- Blood Culture. - Blood PCR
- FBC & Clotting to assess for DIC
- LP is usually CI
Hallmark Features of Botulism ??
C botulinum; Gram (+)ve Anaerobic Bacillus; 7 Serotypes A-G
- Neurotoxin => Irreversibly (-) ACh release at post-synaptic membrane
- MC affects Bulbar muscles & ANS
C/F of Botulism ??
Results from eating Contaminated Food (eg.- Tinned) or IVDU
- Fully Conscious with No Sensory deficits
- Flaccid Paralysis. - Diplopia
- Ataxia - Bulbar Palsy
TREATMENT
- Botulism Anti-toxin (ONLY effective if given early) & Supportive Care
- Anti-toxins will NOT work if toxins are bound
What id SEPSIS & SEPTIC SHOCK ??
Life threatening organ dysfunction due to Dysregulated host response to an infection
More severe form of sepsis- ‘Circulatory, cellular & Metabolic abnormalities are a/w greater risk of Mortality than with sepsis alone’
- Vasopressors needed to maintain MAP >= 65 mmHg
- S. Lactate > 2mmol/L in the absence of Hypovolemia
What id qSOFA score ??
Adult pts. outside the ICU with suspected infection are identified as being at high risk of Mortality if their qSOFA is >= 2 of the following
- RR > 22/ min
- Altered Mentation
- SBP < 100 mmHg
Components of Full SOFA score ??
The following are scored from 0 to 4
- Pa/O2 or FiO2
- Platelets
- Bilirubin umol/l
- Creatinine umol/L
- CVS (MAP & DA requirement)
- GCS
- Urine Output ml/day
What is Sepsis six protocol ??
- Give O2 (Sats. at > 94% & 88- 92% if at risk of CO2 retention)
- Take Bloods for Culture
- Give Broad-spectrum Abx.
- Give IV Fluids (a bolus of 500 ml Crystalloid in < 15 min)
- Measure S. Lactate
- Measure Urine Output hourly
What are the Red Flag Criteria of Sepsis ??
What are the Amber Flag Criteria of Sepsis ??
Hallmarks of Brucellosis ??
Zoonosis, MC in Middle East & in Farmers, Vets & Abattoir workers
4 major species cause infections
- B melitensis (Sheep)
- B abortus (cattle)
- B canis
- B suis (Pig)
Treatment
- DOXYCYXLINE & STREPTOMYCIN
Features of Brucellosis ??
Fever, Malaise
Hepatosplenomegaly
Sacroiliitis: Spinal tenderness (+)ve
Diagnosis
- Ix.oC: Brucella Serology
- Screening: Rose Bengal plate test
- Blood & Bone morrow Cultures (often negative)
Rx. & Complications of Brucellosis ??
Doxycycline & Streptomycin
Osteomyelitis
Infective Endocarditis
Meningoencephalitis
Orchitis
Hallmarks of Campylobacter jejuni ??
MCC of bacterial Intestinal disease in the UK; Incubation- 1- 6 days
- Gram (-)ve bacillus
- Faeco-Oral route
C/F
- Prodrome: Headache, Malaise
- Diarrhoea: often Bloody
- Abdominal Pain: May mimic Appendicitis
Rx. of C Jejuni ??
Usually Self limiting
Treat only if
- Severe infection (High Fever, Bloody diarrhoea > 8 stools/ day, c/f for > 1 week)
- Immunocompromised
- 1st line: CLARITHROMYCIN
- 2nd line: Ciprofloxacin
Complications a/e C Jejuni infection ??
- GBS
- Reactive Arthritis
- Septicaemia
- Endocarditis
- Arthritis
Type of toxins produced by C Difficile infection ??
Clostridia
Exotoxin & Cytotoxin
Gram (+)ve, Obligate Bacilli
Hallmark of Chlamydia ??
MC STI in the UK; C trachomatis- an Obligate intracellular pathogen
- Incubation: 7- 21 days
- Most cases are Asymptomatic (70% women & 50% Men)
WOMEN: Cervicitis (Discharge, Bleed), Dysuria
MEN: Urethral Discharge, Dysuria
Ix. done in Chlamydia ??
IoC: NAAT
- 1st void urine sample, Vulvovaginal swab or Cervical swab is used
- WOMEN: VV swab is 1st line
- MEN: Urine test is 1st line
Test is done 2 wks after possible exposure
SCREENING Teat
- Open for all men & women aged 15- 24 years
- Relies on Opportunistic testing
Pap Smear: RED INCLUSION Bodies
Rx. of Chlamydia ??
1st line: DOXYCYCLINE * 7 days
2nd line: Azithromycin (1g OD on day 1 => 500mg OD for next 2 days)
Pregnant Women
- DoC : AZITHROMYCIN 1g
- 2nd line: Erythromycin/ Amoxicillin
Partner Notification
Why is Doxycycline preferred over Azithromycin in Rx of Chlamydia ??
Due to Mycoplasma Genitalium
- This infection is coexistent with Chlamydia & it has evidence of Macrolide resistance
Partner Notification in Chlamydia ??
Partner Notification
- Men with C/F: All contacts in last 4 wks prior to onset of c/f
- Women + C/F & Asymptomatic Men: All partners in last 6 months (OR) the most recent ones must be contacted
Contacts of confirmed Chlamydia cases should be offered Rx prior to the results of their Ix- TREAT then TEST
Complications a/w Chlamydia ??
- Epididymitis. - PID
- Endometriosis
- Ectopic Pregnancy
- Infertility. - Reactive Arthritis
- PERI-HEPATITIS (Fitz-Hugh-Curtis)
Hallmarks of Lymphogranuloma Venerum ??
Caused by C trachomatis serovars-
- L1, L2 & L3
RFs-
- MSM. - HIV in developed nations
- Historically more common in TROPICS
Stages & Rx. of LGV ??
3 Stages
- S 1 : Small PAINLESS pustule, later forms an ulcer (Small, Shallow)
- S 2 : Large PAINFUL Inguinal LNs (Groove sign) can later form Fistulating Buboes
- S 3 : Proctocolitis
Treatment
- DOXYCYCLINE
Which serovar of C trachomatis causes normal Chlamydia with Urethritis + PID ??
Serovars D through K
Hallmarks of Gonorrhoea ??
Gram(-)ve Diplococci- N gonorrhoea
- ACUTE infection can occur on ANY mucous memb. surface
- Typically: GU but Rectum & Pharynx
- Incubation: 2- 5 days
C/F
- Males: Urethral discharge, Dysuria
- Females: Cervicitis => Vag. discharge
- Rectal & Pharyngeal infection: usually asymptomatic
Rx. of Gonorrhoea ??
Emperical Rx. : CEPHALOSPORINS
1st line: IM Ceftriaxone 1g (single dose)
- do not add Azithromycin
If IM is refused
- Oral Cefixime 400mg (single dose) + Oral Azithromycin 2g (single dose)
If sensitivities are known & if the organism is sensitive to Ciproflaxacin
- Oral Ciplox 500mg single dose
Why is immunization not possible & reinfections very common in N gonorrhoea infection ??
Antigen Variation of
- Type 4 Pili (proteins that adhere to surfaces) &
- Opa proteins (surface proteins which binds to receptors of Immune cells)
Complications of N gonorrhoea ??
Local: Urethral stricture, Epididymitis, Salpingitis (can cause Infertility)
DISSEMINATED Infection
Features of Disseminated Gonococcal Infection & Gonococcal Arthritis ??
Gonococcal infection is the MCC of Septic Arthritis in Young adults
DGI is due to blood spread from mucosal infection
The following Triad is seen initially-
- TENOSYNOVITIS
- MIGRATORY POLYARTHRITIS
- DERMATITIS (Maculo-Papular or Vesicular)
Late Complications
- Endocarditis
- Peri-hepatitis (Fitz-Hugh-Curtis)
Hallmarks of Bacterial Vaginosis ??
Gardnerella vaginalis (Anaerobe)
- Decreases Lactobacilli (anaerobes) => reduced Lactic acid => Raised Vaginal pH.
- NOT an STI, but is exclusively seen in sexually active women
- THIN, Grey-white, FISHY offensive discharge
- Vag. Itching (Uncommon)
What is Amsel’s Criteria
Dx. of Bacterial Vaginosis 3/4 should be (+)ve
- THIN, white-grey homogenous discharge
- Microscopy: Clue cells (Stippled Vag. Epithelial cells)
- Vaginal pH > 4.5
- WHIFF Test (+)ve : Addition of KOH => Fishy odour
Rx. of Bacterial Vaginosis ??
Oral Metronidazole for 5- 7 days
- Topical Metronidazole or Topical Clindamycin are alternatives
- 70- 80% Initial cure rate
- Relapse rate > 50% in 3 months
Even in PREGNANT Women, same Rx. is followed
Hallmark of Trichomonas Vaginalis ??
Highly motile, Flagellated Protozoan PARASITE & is a STI
Clinical Features
- FROTHY, offensive, Yellow green vaginal discharge
- Vaginal ITCH (common)
- Vulvovaginitis
- Strawberry cervix
- pH > 4.5
Men: Usually asymptomatic BUT can cause Urethritis
Ix. & Rx. of T Vaginalis infection ??
Microscopy: Wet mount- Motile Trophozoites
Oral METRINIDAZOLE * 5- 7 days
Oral Metronidazole 2g single dose
Hallmarks of Woolsorter’s disease ??
Bacillus Anthracis [Gram (+)ve Rods]
- Spread by Infected Carcasses
Produces- TRIPARTITE Protein Toxin
- Protective antigen
- Oedema factor: bacterial Adenylate cyclase => increases cAMP
- Lethal factor: Toxic to Macrophages
Features of Woolsorter’s disease ??
Painless Black Eschar
- Cutaneous ‘Malignant pustule’ but NO pus
Painless & Non-tender
- Marked oedema. - GI bleed
Treatment
- Cutaneous Anthrax: CIPLOX
- Further Rx is based on microbiology Ix. & Expert advice
Hallmarks of Diphtheria??
Corynebacterium diphtheria [Gram (+)ve bacteria]
- releases EXOTOXINS encoded by Beta-prophage
- Exotoxin =(-)=> Protein synthesis by catalysing ADP-ribosylation of EF-2
- Toxin causes ‘D Membrane’ on tonsils caused by necrotic mucosal cells
- Systemic distribution: Necrosis of Myocardial neural & Renal tissue
Features of Diphtheria ??
Recent travel to Eastern Europe/ Russia/ Asia
- Sore throat + Dirty grey Pseudo memb. on Posterior pharyngeal wall
- Bull neck: Bulky Cervical LNpathy
- Neuritis eg.- CN involved
- Heart Block
Ix. & Rx. of Diphtheria ??
Throat swab culture
- uses Tellurite agar/ Loeffler’s media
IM Penicillin
Diphtheria Anti-toxin
Hallmark of Enteric Fever ??
Salmonella group [Gram (-)ve rods], not a gut commensal
Typhoid & paratyphoid are caused by S typhi & S paratyphi (types A, B, C)
- Faeco-oral route
- Contaminated food & water
Features of Enteric Fever ??
Initial: Headache, Fever & Arthralgia
- Relative Bradycardia
- Abd. Pain & Distension
- CONSTIPATION (more common in TYPHOID, although salmonella is a recognised cause of Diarrhoea)
- ROSE Spots (on the Trunk in 40% cases & is MC in PARATYPHOID)
Complications of Enteric Fever ??
Osteomyelitis
- Especially in SCD where Salmonella is one of the MC pathogen)
GI Bleed/ Perforation
Meningitis
Cholecystitis
Chronic Carrier state (1% cases & is more likely an adult Female)
Rx. of Enteric Fever ??
Hallmark Features of E coli ??
Gram (-)ve Rod, Facultative Anaerobic, Lactose- Fermenting
- Present in normal gut flora
Causes variety of diseases in Humans
- Diarrhoeal illness
- UTIs
- Neonatal Meningitis
What are the Serotypes of E coli ??
Classified based on ANTIGENS which may trigger an Immune response
- O : Lipopolysaccharide layer
- K : Capsule
- H : Flagellin
E coli O 157:H7 is a/w
- Severe, bloody, watery disrrhoea
- High Mortality & is a/w HUS
- Spread by Contaminated Ground BEEF
Which subtype of E coli causes Neonatal meningitis ??
E coli serotype Capsular Antigen K1
Hallmark of Shigella ??
Diarrhoea (may be Bloody), Abd. Pain
Severity depends on type
- S sonnei (eg from UK) may be mild
- S Flexineri or S Dysenteriae from Abroad may cause severe disease
Self-limiting Infection & normally do not require Abx. Rx.
DoC- CIPROFLOXACIN is given if
- Severe Infection
- Immunocompromised
- Bloody Diarrhoea
Hallmark of Giardiasis ??
Giardia lamblia (Flagellate protozoan)
- Faeco-Oral Route
- Foreign travel, - MSM
- Swimming/ Drinking Water from river or lake
Treatment
- METRONIDAZOLE
Features of Giardiasis ??
Asymptomatic
Lethargy, Bloating, Abdominal Pain
Flatulence, Non-Bloody Diarrhoea
Malabsorption & Steatorrhoea
Chr. Diarrhoea, Lactose Intolerance can occur
Ix. done in Giardiasis ??
Stool Microscopy for Trophozoite & Cysts (65% sensitivity)
Stool Antigen detection Assay
- Greater sensitivity & Faster turn around time than microscopy
- PCR assays
Rx.- METRONIDAZOLE
Features of Cholera ??
Vibro Cholerae, Gram (-)ve bacteria
- Profuse ‘Rice Water’ Diarrhoea
- Dehydration
- Hypoglycaemia
Treatment
- Oral Rehydration Therapy
- DOXYCYCLINE, CIPROFLOXACIN
Causes of Community Acquired Pneumonia ??
Strept. Pneumonia (80% cases)
- Pneumococcal pneumonia
- Common after Cold sores (Herpes labialis)
H Influenzae
Staph. Aureus (Common after Influenza infection)
Atypical P (eg- Mycoplasma Pneumoniae)
Viruses
Klebsiella (classic in Alcoholics)
Hallmarks of Legionnaire’s disease ??
Leigionella pneumonia (Intracellular)
- Colonizes H2O tank- eg.-AC, Foreign holidays
- Person-to-person, NO transmission
Diagnosis:
- URINARY ANTIGEN
- CXR: Non-specific, but Mid-Lower Zone Predominance of Patchy Consolidation
Features of Legionnaire’s disease ??
Flu like C/F including
- Fever (> 95% cases)
- DRY Cough
- Relative Bradycardia. - Confusion
- LYMPHOPAENIA. - HYPO Na+
- Deranged LFTs
- Pleural Effusion (30% cases)
Treatment:
ERYTHROMYCIN or CLARITHROMYCIN
Hallmark of Mycoplasma Pneumoniae ??
Causes Atypical Pneumonia + YOUNG patients;
- a/w Characteristic Complications
- Epidemics- occurs EVERY 4 yrs
- Do not respond to Penicillins or Cephalosporins (lack of cell wall- Peptidoglycan)
Features of Mycoplasma Pneumoniae ??
PROLONGED & GRADUAL onset
- Flu like illness precede DRY Cough
- B/L Consolidation on CXR
- COMPLICATIONS may occur
Investigations
- Mycoplasma SEROLOGY
- (+)ve COLD Agglutination Test
Treatment
- DOXYCYCLINE or MACROLIDES (erythromycin/ Clarithromycin)
Complications seen in Mycoplasma Pneumonia ??
- COLD Agglutinins IgM: May cause an Haemolytic anaemia, Thrombocytopaenia
- ERYTHEMA Multiforme, E Nodosum
- Meningoencephalitis, GBS & other Immune-mediated CNS disease
- Bullous Myringitis: Painful vesicles on Tympanic Memb.
- CVS: Pericarditis/ Myocarditis
- GIT: Hepatitis, Pancreatitis
- RENAL: Acute GN
Name the Virus which causes
- Cold Sores
- Genital Herpes
Herpes Simplex Virus 1
- Predisposed to Strep. Pneumonia
HSV 2
- Primary attack: Severe & a/w Fever
- Subsequent attacks: Less severe & Localised at one site
- Multiple, small, grouped ulcer; Shallow with Erythematous base
- Cowdry Type A: Multinucleated Giant cells & Intranuclear Inclusions
What is Lemierre’s Syndrome ??
Infectious Thrombophlebitis of Internal Jugular Vein
- Secondary to Bacterial Sore throat => Peritonsillar abscess
- FUSOBACTERIUM NECROPHORUM
Spread of infection lateral to the abscess + Compression => Thrombosis of IJV
H/o: Sore throat => Neck pain, Stiffness & Tenderness (may be MISTAKEN for Meningitis) & Systemic Involvement (Fever, Rigors, etc.)
Septic Pulm. Emboli can also occur
What is Donovanosis ??
Granuloma Inguinale
Klebsiella granulomatosis previously called Calymmatobacterium granulomatosis
- Extensive Progressive PAINLESS Ulcers
- NO LNpathy
- Base has Granulation tissue
- Donovan Bodies: Deep staining show Gram (-)ve Intracytoplasmic cysts
Features of Chancroid ??
Tropical disease- H Ducreyi
- Painful genital ulcers
- Multiple, deep, sharply defined, ragged, Undermined border
- Base has Grau- yellow exudate
- ‘School of Fish’: Organisms clamp in long parallel strands
- Painful, U/L Inguinal LNpathy
Features of Syphilis ulcer ??
Seen in Primary stage
Single, Indurated, well circumscribed ulcer (Chancre)
- Clean Base
- Thin delicate, Cork-screw shaped organism on Dark field microscopy
Name the Painful & Painless Genital Ulcers
PAINFUL Ulcers
- Chancroid (H Ducreyi): School of Fish
- Genital H (HSV2): Cowdry Type 2
PAINLESS Ulcers
- Granuloma Inguinale (K granulomatosis): Donovan Bodies
- Syphilis (Chancre
- LGV (C trachomatis): Groove sign, Painful Inguinal LNpathy
Management of Animal bites
Maj. of bites are from Dogs & Cats
- Polymicrobial
- MC isolated: Pasteurella Multocida
Treatment
- Clean the wound
- Puncture wound: Do not suture (unless Cosmetic risk)
- CO-AMOXICLAV
- If Penicillin allergic: Doxycycline + Metronidazole
Management of Human Bites ??
Multimicrobial infection (Aerobes & Anaerobes)
- Streptococci sp.
- Staph. aureus. - Eikenella
- Fusobacterium. - Parvotella
Risk of HIV & Hep. C should be considered
Rx.- CO-AMOXICLAV
Features of Cat Scratch disease ??
Bartonella Henselae [Gram(-)ve Rod]
- H/o Cat Scratch (Teeth or Claws)
- Fever
- Regional LNpathy
- Headache, Malaise
BACILLARY ANGIOMATOSIS
- Severe form
- Primarily in Immunocomprmised
Hallmarks of Leptospirosis ??
Leptospira interrogans (serogroup L. icterohaemorrhagiae) a Spirochaete
- Infected RAT Urine (classic)
- Sewage worker, Farmers, Vets, Abattoirs
- MC in Tropics: Returning Traveller
Rx.-
- High dose BENZYLPENICILLIN or DOXYCYCLINE
Features of Leptospirosis ??
EARLY PHASE (due to Bacteraemia) & lasts for a Week
- Mild or Subclinical
- Fever. - Flu-like Symptoms
- Subconjunctival suffusion (redness/ haemorrhage)
SECOND IMMUNE Phase
- Can lead to Severe disease (Weil’s )
- AKI (50% cases)
- Hepatitis: Jaundice, Hepatomegaly
ASEPTIC Meningitis
Ix. done in Leptospirosis ??
Serology
- Antibodies develop after 7 days
PCR
Culture
- Growth can take several wks.
1st 10 days: Blood & CSF are (+)ve
2nd Week of Illness: Urine Culture
Hallmarks of Listeria infection ??
Gram (+)ve Bacilli; has the ability to multiply at LOW Temperature
- Spread: Contaminated food, Typical- Unpasteurised Dairy product
- Infection is Lethal to unborn child => Miscarriages
Features of Listeria ??
Can present in Variety of ways
- Diarrhoea & Flu-like illness
- Pneumonia, Meningoencephalitis
- Ataxia & Seizures
Investigations
- Blood culture
- CSF: Pleocytosis + TUMBLING Motility on Wet mounts
Rx. of Listeria ??
IV Amoxicillin / Ampicillin + IV Gentamycin
Pregnant women & Listeria ??
20x more likely to develop Listeriosis compared to normal people due to changes in Immune system
- Fetal/ Neonatal infection (Vertical during Child birth or Transplacentally)
- Complications: Miscarriages, Stillbirths, Premature labour, Chorioamnionitis
Dx: Blood Culture
Rx.- AMOXICILLIN
Hallmarks of Lyme’s Disease ??
Borrelia Burgdorferi (Spirochetes)
- Spreads by Ticks
DIAGNOSIS
Dx. Clinically if E migrans (+)ve
1st line: ELISA antibodies to BB
- If (-)ve + Lyme’s still suspected + tested in < 4wks of C/F onset => Repeat ELISA at 4-6 wks after 1st test
- If still suspected who has C/F for >=12 wks => IMMUNOBLOT Test
- If (+)ve or Equivocal => Immunoblot test for Lyme’s is done
Rx. of
- Asymptomatic Tick Bite ??
- Suspected/ Confirmed Lyme’s ??
Remove the Tick using a Fine-tipped tweezers => Wash afterwards
- Do NOT recommend routine Abx. Rx
Early Disease: DOXYCYCLINE
- Amoxicillin (if Doxycycline CI)
If E Migrans (+)ve Start Abx. without the need of further testing
Disseminated disease: CEFTRIAXONE
Features of Lyme’s Disease ??
EARLY Features (within 30 days)
Erythema Migrans (80% cases)
- Bulls eye rash at site of Tick bite
- Seen 1- 4 wks after initial bite but can present sooner
- Painless, > 5cm in diameter & Slowly increases in size
Systemic Features
- Fever, Headache, Lethargy
- Arthralgia
LATE Features (after 30 days)
- CVS: Hert Block, Peri/Myocarditis
- CNS: CN-7 palsy, Radicular pain, Meningitis
Hallmarks of Mycobacterium Marinum ??
Fish tank Granuloma [Exposure to or frequently work with Fish]
- Incubation: 3- 4 wks
- Lesions are painful or painless
Sporotrichoid spread: Cut in skin => enters blood stream => Lymphatics
Rx:
- Tetracyclines, Fluoroquinolones, Sulfonamides & Macrolides
What is Jarish-Herxheimer Reaction ??
Seen after initiating Abx. Rx.
- Fever, Rash, Tachycardia after 1st dose of Abx.
- No Anaphylaxi, wheeze or Hypotension
- Due to release of Endotoxins after bacterial death seen within a few hrs. of Rx.
- More common in Syphilis
- Also seen in Lyme’s disease
Rx.- Antipyretics
Types of Leprosy ??
Degree of CMI determines the type of leprosy
Lepromatous L (Multibacillary)
- Extensive skin involvement
- Symmetrical Nerve involvement
- LOW CMI
Tuberculoid L (Paucibacillary)
- Limited Skin disease
- Asymmetrical nerve involvemeny
- Hair loss
- HIGH CMI
Hallmark of Leprosy ??
Granulomatous disease affecting the Peripheral nerves & Skin
- Mycobacterium Laprae
- Hypopigmented skin patches - Buttocks, Face & Extensor surface of limbs
- Sensory loss
Treatment
- Rifampicin, Dapsone & Clofazimine
Hallmarks of Measles ??
Outbreaks occurs when vaccination rates drop
- RNA Paramyxovirus
- Aerosol transmission
- Infective period: Prodrome till 4 days after rash starts
- Incubation: 10- 14 days
Ix. : IgM antibody detected within few days of Rash onset
Features of Measles ??
Prodrome phase
- Fever, Conjuctivitis, Irritable
Koplik spots
- Develops before rash
- White spots (‘grain of salt’) on Buccal mucosa
RASH (starts behind the Ear)
- Ear => whole body
- Discrete Maculo-Papular rash becoming Blotchy & Confluent
- Desquamation: SPARES Palms & Soles may occur after a week
Diarrhoea (10%)
Rx. of Measles ??
Supportive
Admission if
- Immunocompromised
- Pregnant females
Notifiable disease
Contacts
- If Not immunized against measles=> MMR is offered(vaccine induced measles antibody develops more rapidly than natural infection)
- Given in < 72 hrs
Complications of Measles ??
Otitis Media (MC complication)
Pneumonia (MCC of DEATH)
Encephalitis (occurs 1- 2 wks after onset of illness)
Subacute Sclerosing Panencephalitis
- Very rare; Presents 5- 10 yrs after illness
Febrile Convulsions
Keratoconjunctivitis, Corneal ulceration
Diarrhoea
Increased incidence of Appendicitis
Myocarditis
Rx. of Lower UTI in
- Men ??
- Catheterised pts. ??
Immediate Abx. * 7 days
1st line: Trimethoprim or Nitrofurantoin unless Prostatitis is suspected
Do NOT treat Asymptomatic Bacteriuria in Catheterised pts.
If pt. is symptomatic, they should be treated with Abx
- 7 days Rx. + Remove/ Change catheter asap if it was in place for > 7 days
Hallmark features of Lower UTI in Adults ??
Non-Pregnant Women
- Trimethoprim or Nitrofurantoin * 3 days
- Send for a Culture if > 65 yrs old
PREGNANT Women
If Symptomatic
- Urine Culture sent in ALL cases
- 1st line: Nitrofurantoin (avoided near term)
- 2nd line: Amoxicillin or Cefalexin
If Asymptomatic Bacteriuria
- Urine Culture done routinely at 1st Antenatal visit
- Immediate Nitrofurantoin/ Amoxicillin or Cefalexin * 7 days
- It is treated to Prevent progression to Acute Pyelonephritis
- Test of Cure: Urine Culture
Features of PID ??
- Lower Abd. Pain
- Fever, Dysuria, Menses irregular
- Deep Dyspareunia
- Vaginal or Cervical discharge
- Cervical excitation
Investigation - Pregnancy test (to exclude preg.)
- High Vaginal Swabs [often (-)ve]
- Screen for Chlamydia & Gonorrhoea
Hallmarks of Non-Gonococcal Urethritis ??
NGU aka Non-Specific Urethritis
- Urethritis + Gonococcal bacteria are NOT identifiable on 1st swab
- Typical case: Male comes to GUM clinic with Purulent urethral discharge & dysuria
Swab (Microscopy): Neutrophils (+)ve but NO Gram(-)ve diplococci
Pt. requires immediate Rx. prior to waiting for Chlamydia test to come back so, an Initial dx. of NGU is made.
Rx. of Acute Pyelonephritis ??
Hospital Admission considered
- Broad spectrum Cephalosporins or Quinolones (For Non-pregnant women) * 10-14 days
Hallmark of PID ??
Infection & Inflammation of Female Pelvic organ including- Uterus, Tubes, Ovaries & surrounding Peritoneum
- Result of an Ascending infection from the Endocervix
Causitive Organisms
- C Trachomatis (MCC)
- N Gonorrhoea
- Mycoplasma Genitalium
- Mycoplasma Hominis
Cause & Rx. of NGU ??
C trachomatis (MCC)
Mycoplasma Genitalium
- Causes MORE c/f than Chlamydia
Treatment
- Contact tracing
- Oral Doxycycline or Azithromycin
Complications of PID ??
Peri-Hepatitis (Fitz-Hugh-Curtis S)
- Seen in 10% of cases
- RUQ pain, can be confused with Cholecystitis
Infertility
Chr. Pelvic Pain
Ectopic Pregnancy
Hallmarks of Syphilis ??
Treponema pallidum, spirochetes spiral shaped, Incubation: 9- 90 days
PRIMARY Features
- Chancre
- Local non-tender LNpathy
- Often NOT seen in women (lesion may be on Cervix)
SECONDARY Features
- Seen 6-8 wks after primary infection
- Fever, LNpathy
- RASH on Trunk, Palm & Soles
- Buccal: SNAIL Track ulcers
- Condylomata lata: Painless, Warty lesions on genitalia
Rx. of PID ??
Oral Ofloxacin + Oral Metronidazole (OR) IM Ceftriaxone + Oral Doxycycline + Oral Metronidazole
- Mild cases: IUContraceptive Dsmay be left in.
- Removal of IUD may be a/w better short term clinical outcome
Causes of False Positive Non-Treponemal (Cardiolipin) test ??
SomeTimes Mistakes Happen (SLE, TB, Malaria, HIV)
Pregnancy
APLS
Leprosy
EBV, Hepatitis
Features of -
- Tertiary Syphilis ??
- Congenital Syphilis ??
- Gummas (Granulomatous lesion of skin & bones
- Ascending orta aneurysm
- General Paralysis of the insane
- Tabes dorsalis
- Argyll-Robertson pupil
Hutchinson’s teeth (Blunted upper incisor teeth), Mulberry Molars
Rhagades (Linear scar at mouth angle
Keratitis
Saber shins
Saddle nose
Deafness
Difference b/w
- Non-Treponemal tests
- Treponemal tests
- Not specific, can be FP
- Based on Reactivity of serum from infected pts. to a Cardiolipin-Cholesterol-lecithin antigen
- Assess QUALITY of antibody produced
- Becomes (-)ve after Rx
eg.- RPR, VDRL
More complex, expensive but Specific
Qualitative only- reported as Reactive or Non-reactive
Eg.- TP-EIA (T pallidum EIA), TPHA (T pallidum Haemagglutination test)
Rx. of Syphilis ??
1st line: IM Benzathine Penicillin
Alternative: Doxycycline
Name the type of infection identified from the following results
- (+)ve Non-Treponemal + (+)ve Treponemal ??
- (+)ve Non-T + (-)ve T Test ??
- (-)ve Non-T + (+)ve T Test ??
- Active Syphilis Infetion
- False Positive Syphilis
- Successfully treated Syphilis
Name the infection caused by the following serotypes of C Trachomatis - Types A, B, C
- Types D to K
- Types L1, L2, L3
- Chronic infection, Causes Blindness (Follicular conjuctivitis), common in Africa
- Urethritis/ PID, Ectopic pregnancy, Neonatal Pneumonia (STACCATO Cough) with Eosinophilia, Neonatal Conjuctivitis (1-2 wks after birth)
- LGV : Small, painless ulcers on genitals + Painful Inguinal LNpathy that may ulcerate (Buboes)
Hallmark features of Rickettsiae ??
Gram(-)ve Obligate Intracellular PARSITES
- All the variety of diseases causes Rash except Q-fever (Pneumonia + No Rash)
- Rx.- TETRACYCLINES
RASH Common Diseases
- Rocky Mountain Spotted Fever
- Typhus
RASH Rare
- Ehrlichiosis. - Anaplasmosis.
- Q Fever
Features of Rocky Mountain Spotted Fever ??
Rickettsia rickettsii, Tick borne
- Primarily seen in South Atlantic states (especially North Carolina)
RASH- Starts at Wrist & Ankle =spreads=> Trunk, palms & soles
- Headache. - Fever. - Rash
Initially Maculo-papular before becoming Vasculitic
Features of Typhus (Endemic or Epidemic) ??
Endemic (Fleas): R Typhi
Epidemic (Human Body Louse)
- R Prowazekii
RASH: Starts CENTRALLY => Spreads out & Spares Palms & Soles
- Black eschar at site of innoculation
- Maculopapular or Vasculitis
“Rickettsii on Wrist & Typhus on Trunk”
Features of Ehrlichiosis & Anaplasmosis ??
MEGA
- Monocytes : Ehrlichiosis
- Granulocytes : Anaplasmosis
Ehrlichia, vector- Tick
- Monocytes with morulae (Mulberry like inclusions) in cytoplasm
ANAPLASMA, vector- Tick
- Granulocytes with morulae in cytoplasm
Features of Q-Fever ??
Coxiella burnetii, NO Vector & NO Rash; Endospore forms (can survive outside)
- Bacterium Inhales as aerosols from cattle/ sheep Amniotic fluid, abattoir or Infected dust
- Headache, Cough, Flulike symptoms
- Atypical Pneumonia +/- Hepatitis
- Transaminitis
- Common cause of Culture (-)ve Endocarditis
Rx.- DOXYCYCLINE
Infections where Palms & Soles rash are seen ??
“CARS”
- Coxsackievirus A (Hand-Mouth & Foot disease)
- Rocky Mountain Spotted Fever
- Secondary Syphilis
Tick Typhus causitive organism ??
R Conorii
Rash starts at AXILLA then spreads
Hallmarks of Orf ??
Condition found in Sheep & Goats; it can be transmitted to humans
- PARAPOX Virus
- In animals: Scabby ;esions around mouth & nose
In Humans
- Hands & Nose
- Initial: Small, Red, raised papules
- Later: Increase in size to 2-3cm & become flat-topped & haemorrhagic
Tetanus vaccination ??
It is a Cell-Free Purified toxin
It is given as part of Routine Immunizaton schedule at
- 2 months. - 3 months. - 4 months
- 3- 5 yrs. - 13- 18 yrs
Features of Tetanus ??
Prodrome fever, lethargy, Headache
- Trismus (Lockjaw)
- Risus sardonicus
- Opisthotonus (arched back, hyperextended neck)
- Spasms (eg.- Dysphagia)
Treatment
- Supportive (Ventilator, Muscle relaxants)
- IM Human Tetanus IGs for high risk
- METRONIDAZOLE is the Abx. of choice (& not Benzylpenicillin)
Features of
- Clean wound ??
- Tetanus prone wound ??
< 6 hrs old, Non-Penetrating with negligible tissue damage
- Puncture type + acquired at Contaminated area
- Wounds has Foreign body
- Compound #
- Wounds/ Burns with Systemic sepsis
- Certain Animal bite & Scratches
Features of High-Risk Tetanus prone wound ??
- Heavy Contamination which contain tetanus spores eg.- Soil, manure
- Wounds/ Burns show extensive devitalised tissue
- Requires surgical intervention
Hallmark of Whitmore’s disease ??
aka MELIOIDOSIS [Gram(-)ve]
- Burkholderia pseudomallei
- Saprophytes in soil & Fresh water in Endemic regions
- Tropics & Subtropics- Southeast Asia (Thailand, Malaysia) & Northern America
- MC during Wet seasons
- Percutaneous Innoculation (MC)
- Inhalation, Aspiration, Ingestion
- Person-to-Person transmission is rare
Features of Whitmore’s Disease ??
Incubation: 1- 21 days (Mean 9 days)
Can be- Acute/ Chronic (>2 months)/ Reactivation of Latent Infection
Clinical Features
- Acute Pulm. Infection (MC)
- Skin ulcer, Nodule or Abscess
- Visceral abscess: Prostate, Spleen, Kidney & Liver
- Disseminated: 55% cases, Fever + Septic Shock
Ix. & Rx. of Meliodosis ??
CULTURE (Mainstay)
Gram stain: Sputum/ Pus
CXR- signs of Acute pneumonia
Treatment
- Initial: IV Ceftazidime, Imipenam or Meropenam * 10- 14 days
- Eradication: Oral TMP/SMX + Doxy. * 3 to 6 months
- Abscess drainage
- No vaccination available
Indications of BCG vaccine in the UK ??
1) All infants (0- 12months) where the
- Annual TB incidence- > 40/100,000
- Parent/ Grandparent born in a country where TB incidence > 40/100,000
- The same applies to older kids but if they are >=6 yrs old, 1st do a Tuberculin test before BCG
2) Previously unvaccinated Tuberculin (-)ve contacts of cases if Pulm. TB
3) Previously unvaccinated Tuberculin (-)ve new entrants < 16 yrs who were born in/ lived for >=3 months in a country with >40/100,000 incidence
4) Healthcare workers
5) Prison Staff
6) Staffs of Elderly care home
7) Those who work with Homeless
CI of BCG vaccine ??
- Previous BCG vaccination
- Pregnancy. - > 35 yrs old
- PHx of TB. - HIV
- (+)ve Tuberculin test [Heaf or Mantoux]
How is BCG vaccine administered ??
1st do- Tuberculin Skin Test (Only exception is kids < 6 yrs + No contact with TB)
- Intradermally on lateral aspect of Left upper arm
- Contains Live attenuated M Bovis
- Offers limited protection to Leprosy
- Can be given simultaneously with other live vaccine
- If not given simultaneously, wait for 4 wks
Which infections are Post-Splenectomy pts. are prone to ??
Pneumococcus
Haemophilus
Meningococcus
Capnocytophaga canimorsus
What vaccinations are given priorly in pts. undergoing Elective Splenectomy ??
Vaccinated 2 weeks Before or After Splenectomy
- HiB, Meningitis C
Pneumococcal PPVaccine at 2 wks
- YOUNG Kids: Conjugated vaccine (PCV) is offered as it is more immunogenic but covers few serotypes
- Men ACWY vaccine 1 month later
- Those < 2yrs require booster at 2 yrs of age
- Annual Influenzae vaccination
- Pneumococcal vaccine every 5 years
Indications for Splenectomy
- Trauma (1/4th of cases)
- Spontaneous Rupture: EBV
- Hypersplenism; H Spherocytosis or Elliptocytosis
- Malignancy: Lymphoma, Leukaemia
- Splenic cysts, Hydatid cyst, Abscess
Abx. Prophylaxis for Splenectomy ??
PENICILLIN V
- Continued for at least 2 years &/or
- The pt. is 16 yrs of age
Majority of pts. are put on Abx. Prophylaxis for Life
What are the Post Splenectomy changes ??
PLATELETS rise 1st
Blood Film changes
- Howell-Jolly bodies. - Targer Cells
- Pappenheimer bodies
Increased risk of Post Splenectomy Sepsis (By Encapsulated organisms)
Most sensitive test to detect Hyposplenism ??
Radionucleotide labelled Red Cell Scan
Complications of Splenectomy ??
Haemorrhage
- From Short gastric or Splenic Hilar vessels
Pancreatic Fistulae (Iatrogenic damage to pancreatic tail)
Thrombocytosis: Give Aspirin
ENCAPSULATED Bacteria Infection
- Strept. pneumonia, HiB &
- N meningitidis
What is Post Splenectomy Sepsis ??
Caused by Encapsulated organisms
- Splenectomy => Hyposplenism => Opsonised organism => Goes Undetected at an Immunological level
High risk are
- Immediately after Sx. & in
- Age < 6yrs & > 50 yrs &
- Poor response to Pneumococcal vaccine
Rx.- Penicillin V 500mg BD or Amoxicillin 250mg BD
Hallmark features of Enterovirus ??
Positive sense single stranded RNA viruses
The Family contains
- Coxsackievirus. - Echovirus.
- Rhinovirus & others
MCC of Viral Meningitis in adults
Also cause the following diseases
- Hand, Mouth & Foot disease
- Herpangina. - Pericarditis
What is Erythema infectiosum ??
Parvovirus B19, a DNA virus
- MC in young children
- Parents, Daycare workers, Siblings
- Pregnant Mother
Immunocompromised pts.
- Pancytopaenia
APLASTIC Crisis
- P-B19 suppresses Erythropoiesis for about 1 wk., so Aplastic anaemia is rare unless Chr. Haemolytic anaemia is present
Parvovirus B19 at Pregnancy ??
Virus can affect unborn baby in first 20 wks POG
- Maternal IgM,IgG should be checked
Virus can cross the plancenta
- Fetal Erythropoiesis suppressed =. Severe anaemia => Heart Failure => Fluid accumulation in serous cavity => Hydrops Fetalis
Rx: Intrauterine Blood Transfusions
Hallmarks of Slapped Cheek syndrome ??
Erythema Infectiosum or Fifth disease
- Rose-Red Rash on cheeks
- Can spread to rest of body
- Palms & Soles are SPARED
- Infectious 3 to 5 days before Rash appears
Kids begins to feel better once rash appears
- Rash can appear later with a warm bath, sunlight, heat, fever: No specific Rx.
- School Exclusion NOT required
Hallmarks of Chikungunya ??
ALPHA-VIRUS caused by Aedes aegptyi or A albopictus
- Common in Africa, Asia & India
- 1st reported in Tanzania
Clinical Features
- SEVERE Joint Pain. - Flu like Illness
- High Fever (Abrupt onset)
- Myalgia, Headache, Fatigue
- Rash may develop
Rx: Symptomatic
How to differentiate b/w Chikungunya & Dengue ??
Both have same C/F but
- Severe, Debilitating Joint pain is seen in Chikungunya than in Dengue
Diseases a/w EBV ??
Malignancies
- Burkitt’s Lymphoma (Both African & Sporadic form)
- Hodgkin’s Lymphoma
- Nasopharyngeal CA
- HIV associated CNS Lymphoma
Non-Malignant Conditions
- Hairy Leukoplakia
Hallmark features of CMV ??
CMV is a Herpes virus; only causes disease in Immunocompromised (HIV, Organ Transplant pts.)
Can cause the following
- Congenital CMV Infection
- CMV Mononucleosis (IM like illness in Immunocompromised)
- CMV Retinitis
- CMV Encephalopathy
- CMV Pneumonitis - CMV Colitis
HP feature of CMV ??
OWL’S Eye appearance
- Infected cells
- Due to Intranuclear Inclusion bodies
Features of Congenital CMV ??
Growth Retardation, Microcephaly
Pin-point Petechial ‘Bluberry muffin’ skin lesion
SNHL, Encephalitis
Hepatosplenomegaly
Hallmarks of CMV Retinitis ??
HIV pts. + CD4 count < 50
- Blurred vision
- Fundoscopy: Pizza retins- Haemorrhage & Necrosis
DoC: IV Ganciclovir
Hallmarks of Chickenpox ??
Primary infection by VZVirus
[Shingles: Reactivation of dormant virus in Dorsal Root ganglion]
- Infectivity: 4 days before & 5 days after Rash appears
- Incubation: 10- 21 days
Features of Chickenpox ??
More severe in Older kids & Adults
- Fever & Systemic upset
- Rash (itchy): Starts on Head/Trunk & then spreads.
- Macular => Papular => Vesicular
Rx.- Keep Cool, Trim Nails, Calamine L
School Exclusion: Most infectious period is 1-2 days before rash onset but it continues till all rash has crusted over (5 days after rash onset)
Complications of Chickenpox ??
MC Complication: Secondary Bacterial Infection of lesions (Cellulitis, Rarely- Grp.A Strept.=> Nec. Fasciitis)
- NSAIDs may increase this risk
Pneumonia
Encephalitis (Cerebellum involved)
Disseminated Haemorrhagic Chick.P
Arthritis, Nephritis & Pancreatitis
CXR features of Healed Varicella Pneumonia ??
Miliary opacities secondary to healed varicella pneumonia
- Multiple tiny calcific opacities throughout the lungs
- Uniform size, dense
Hallmarks of Chickenpox in Pregnancy ??
Mother: 5x greater risk of Pneumonitis
Fetus: Fetal Varicella Syndrome
- If mum exposed < 20wks POG, 1% chance of developing FVS
- B/W 20-28 wks, even lesser chance
- After 28 wks almost none
- Skin scarring, Microcephaly, Eye defect (Microphthalmia), Limb Hypoplasia, Learning difficulties
Other risks of Chickenpox to Fetus ??
Shingles in Infancy
- 1-2% risk if maternal exposure in 2nd or 3rd trimester
Severe Neonatal Varicella
- If mum develops rash b/w 5 days before & 2 days after Birth, risk (+)ve
- Fatal to newborn in 20% cases
PEP for Chickenpox during Pregnancy ??
Doubts about Past Hx. of Ck
- Check blood for VZV antibodies
1) If <=20 wks POG + is NOT immune
- Give VZIGs asap
- RCOG suggests VZIG is effective upto 10 days post exposure
2) If >20 wks POG + NOT Immune
- VZIGs or Antivirals (Aciclovir or Vanciclovir) is given from days 7 to 14 post exposure
Rx. of Chickenpox in Pregnancy ??
Pregnant + Develops CkP
- Specialist advise is a must
If >=20 wks POG + presents in < 24hrs of rash onset
- Oral Aciclovir
If < 20 wks POG
- Consider Aciclovir with Caution
Mention the Criteria to determine who would benefit from active PEP
1) Significant exposure to CkP or Herpes Zoster
2) Clinical condition that increases the risk of severe varicella
- Immunosuppressed (Long term Steroids, MTX), Neonates, Pregnant women
3) No antibody to VZVirus
- Starting PEP should not be delayed by > 7 days post exposure
Pts. who fulfil the above criteria can be given VZIGs
Hallmark of HAV infection ??
RNA (Picornavirus) Benign, self-limiting. Incubation: 2-4 wks
- FAECO-Oral route
Flu-like Prodrome
- RUQ pain
- Tender Hepatomegaly
- Jaundice
- Deranged LFTs
Indications for HAV vaccination ??
After an initial dose, Booster dose is given 6- 12 months later
- People travelling to or is gonna reside in High/ Intermediate Prevalence area & is > 1 year
- People with Chr. Liver Disease
- Haemophilia. - MSM - IVDU
- Individuals at Occupational risk: Lab. workers, Staff of large residence, Sewage workers, people who work with primates
Hallmark of HBV infections ??
DNA (Hepadnavirus)
- Source: Blood or Body fluids & Vertical transmission
- Incubation: 6 to 20 wks
Fever, Jaundice, Elevated Liver Transaminases
Rx. of HBV infection ??
1st line : Pegylated IFN-Alpha
- Reduces viral replication in upto 30% Chr. carriers
Better response to Rx is seen in
- Females. - < 50 yrs. - Non-Asian
- Low HBV DNA levels. - HIV (-)ve
- HIGH degree of inflam. on Biopsy
2nd line : Antivirals to suppress viral replication
- Tenofovir, Entecavir, Telbivudine (a synthetic Thymidine Nucleoside analogue)
Complications of HBV ??
Chr. Hepatitis (5- 10%)
- Ground glass hepatocytes on Light microscopy
Fulminant Liver Failure (1%)
HCC.
Glomerulonephritis
PAN
Cryoglobulinaemia
Hallmark of HCV infection ??
Is likely to become a significant health problem in the UK, from the next decade
- RNA Flavivirus
- Incubation: 6- 9 wks
IVDU & pts. who received BT before 1991 (eg. Haemophiliacs)
After exposure to HCV only around 30% ph pts. develop features like
- Transient rise in Aminotransferases, Jaundice
- Fatigue. - Arthralgia
Transmission of HCV ??
Needle stick injury: 2%
Vertical Transmission: 6% (risk is higher if there is coexistent HIV)
Breastfeeding is not CI
Coitus: 5%
No vaccination is available
Ix. & Outcome of HCV infection ??
IoC: HCV RNA (to Dx. Acute infection)
- Pts. after clearing infection will have Anti-HCV antibodies
Outcome
- Clear infection after acute phase: 15- 45%
- Chronic Hep. C: 55- 85%
Hallmark of Chr. HCV infection ??
Persistence of HCV RNA in blood for 6 months
Rx.- (Depends on Viral genotype)
- IFN are not used now
- Aim: Sustained Virological Response (SVR) defines as undetectable serum HCV RNA 6 months after end of Rx.
- Combination of Protease Inhibitor: [Daclatasivir + Sofosbuvir] or [Sofosbuvir + Simeprevir] +/- Ribavirin
Complications of Ribavirin & IFN ??
Haemolytic Anaemia, Cough
Women should not get pregnant in < 6 months of stopping Ribavirin
IFN
- Flu-like-symptoms, Depression, Fatigue, Leukopenia, Thrombocytopenia
Complications of Chr. HCV Infection ??
Arthralgia, Arthritis
Sjogren’s disease
Cirrhosis. HCC
Cryoglobulinaemia type 2 (Mixed Monoclonal & Polyclonal)
Porphyria Cutanea Tarda
- MC seen if a/w alcoholism
MPGN
Hallmarks of Hep. D Infection ??
RNA- single stranded; transmitted parenterally
- Incomplete RNA virus & requires HBV Surface antigen to complete its replication & transmission cycle
- Body fluids; simultaneous B & D infection can occur
Dx.- Reverse PCR of Hep. D RNA
Define the following terms about Hep. D infection
- Co-Infection ??
- Superinfection ??
- HBV & HDV at the same time
- HBV surface antigen (+)ve patient subsequently develops a HDV infection
- Superinfections are a/w high risk of Fulminant Hepatitis, Chr. Hepatitis status & Cirrhosis
Rx.- IFN
Features of Hep. E infection ??
RNA Hepevirus (Faeco-oral route)
- Incubation: 3- 8 wks
- Common in South-East Asia, North & West Africa & in Mexico
Causes a similar disease to HAV but High mortality during pregnancy
- NO Chronic disease or Increased risk of HCC
Hallmark of Herpes Simplex Virus ??
Two strains; 1 & 2
- HSV1 : Oral lesion (Cold sores)
- HSV2 : Genital lesions
BUT now there is considerable overlap
Features
- Primary infection: Severe Gingivo-stomatitis
- Cold sores
- Painful Genital Ulcerations
Rx. of HSV ??
Gingivostomatitis: Oral Aciclovir, Chlorhexidine mouthwash
Cold Sores: Topical Aciclovir
Genital Herpes
- Saline bath, Analgesia, Lidocaine
- Oral Aciclovir
- If frequent exacerbations- Long term Aciclovir
Features of Genital Herpes ??
Painful Genital Ulceration
- a/w Dysuria, Pruritus
Primary infection is more severe than Recurrent episodes
- Headache, Fever, Malaise are more common in Primary infection
Tender Inguinal LNpathy
Ix.oC - NAAT (superior to culture
Serology: is useful in Recurrent genital ulcers of unknown cause
How to deal HSV infection in Pregnancy ??
If Primary attack at > 28 wks POG
- Elective C section is a advised
Recurrent Herpes + Pregnant
- Suppressive Therapy
- Risk of vertical transmission is LOW
HSV histopathology ??
PAP Smear
- Multinucleated Giant cells with HSV
- 3 Ms: Multinucleation, Margination of Chromatin, Molding of nuclei
Hallmark of Japanese Encephalitis ??
MCC of Viral Encephalitis in South East Asia, China, Western Pacific, India
- FLAVIVIRUS,
- Transmitted by CULEX mosquito which breeds on Rice paddy fields
- Reservoir Hosts: Aquatic Birds
- Amplification Hosts: Pigs
Close contact with Pigs is a RF
Features of JE infection ??
Majority of infection- Asymptomatic
- Headache, Fever
- Seizures & Confusion
- Parkinson Features: BG involved (+), Thalamus, Midbrain
- May also present as Acute Flaccid Paralysis
Dx.- Serology or PCR
Rx.- Supportive
Prevention: Vaccination
Hallmarks of Genital warts ??
aka Condylomata lata
- Human Papilloma V- 6, 11
Features
- Small (2- 5 mm) fleshy protuberance , slightly pigmented
- May bleed & Itch
Rx. of Genital Warts ??
1st line: Topical Podophyllum or Cryotherapy
- Multiple Non-Keratinized: Topical agents
- Solitary-Keratinized: Cryotherapy
2nd line: Topiocal Imiquimod
- Offer resistant to Rx. & Recurrence is common
Hallmarks of Viral Haemorrhagic Fever ??
Group of viruses that result in presentations ranging from a Flu-like illness to Multisystem failure
- Flaviviridae: Dengue, Yellow fever
- Areneviridae: Lassa fever
- Filoviridae: Ebola, Marburg virus
- Bunyaviridae: Hantaviruses, Crimean-Congo H F, Rift Valley Fever
Features of VHFs ??
Flu-like symptoms
Abdominal pain
Haemorrhage
- Petechiae, Bruising
- Bloody diarrhoea, Haematemesis, Haemoptysis
- DIC
Multiorgan Failure
Lassa Fever Rx. ??
Contracted by contact with Excreta of infected African Rats (Mastomys rodent) or Person to Person
Rx.- Ribavirin
Hallmark of Yellow fever ??
Type of VHFs
Zoonotic infection: spread by Aedes
Incubation: 2- 14 days
Clinical Features
- Flu-like illness * 1 week
- Sudden onset of High Fever, rigors, N & V, Bradycardia ==Brief remission => Jaundice, Haematemesis, Oliguria
Councilman bodies (Inclusion bodies) seen in Hepatocytes
Hallmarks of Dengue fever ??
Flavivirus- RNA virus
- Vector: Aedes aegypti
- Incubation: 7 days
TYPES
Dengue Fever:
- Without warning signs
- With warning signs
Severe Dengue
- DHF
Features of Dengue Fever ??
Fever, Headache, Facial Flushing
Break-bone fever (Myalgia, Bone pain, Arthralgia)
Pleuritic pain
Maculo-papular Rash
Haemorrhagic Manifestations: (+)ve Tourniquet test, Petechiae, Purpura/ Ecchymosis, Epistaxis
WARNING Signs
- Abd. Pain
- Hepatomegaly
- Persistent Vomiting
- C/F of Fluid accumulation (Ascites, Pleural effusion)
Features of DHF ??
Form of DIC resulting in
- Thrombocytopaenia
- Spontaneous Bleeding
20- 30% of these pts. go on to develop Dengue Shock Syndrome (DSS)
Ix. & Rx. of Dengue Fever ??
Leukopenia, Thrombocytopenia, Raised Aminotransferases
Dx. Test
- Serology
- NAAT for viral antigen
NS1 Antigen Test
Rx.-
- Fluid resuscitation, BT, etc
Hallmark of Marburg Virus ??
Filoviridae family, shares characteristics with Ebola
Cave bats & Primates
- Zoonotic: FRUIT Bats (MC)
- Secondary transmission- contact with Infected PRIMATES
Prevalent outbreaks are documented in African Continent
Features of Marburg Virus ??
Causes VHF very similar to Ebola
- Pyrexia. - Myalgia
- Intense CEPHALGIA
- Haemorrhagic manifestations
Prevention
- Rigorous Isolation Protocols
- Meticulous barrier nursing technique impedes transmission
No Specific Rx.
Halmark of Zika Virus ??
Falvivirus; 1st isolated from monkey in Zika forest in Uganda in 1947
- Aedes mosquito
- Sexually transmitted in a small no. of cases
- Vertical transmission
Fever, Myalgia, Rash, Headache
Arthralgia/ Arthritis, Pruritis
Retro=orbital pain, Conjunctivitis
Complications of Zika Virus ??
GBS
Microcephaly & Congenital abnormalities
Hallmark of Infectious Mononucleiosis ??
Glandular virus: EBV aka HHV-4
Less frequently: CMV & HHV-6
MC in Adolescents & Young adults
Features of Glandular Fever ??
TRIAD
Sore Throat, Pyrexia, LNpathy (Anterior & Posterior triangles of neck
- Malaise, Anorexia, Headache
- Palatal petechiae
- Splenomagaly (in 50% cases)
- Splenic Rupture
- Hepatitis & rise in ALT
- LYMPHOCYTOSIS (50% lymphocytes & 10% atypical lymphocytes)
- Haemolytic anaemia secondary to COLD AGGLUTININS (IgM)
Dx. of Glandular Fever ??
Heterophil Antibody Test (Monospot Test)
IoC - FBC & Monospot Test in 2nd week
Rx. of Glandular Fever ??
Rest during early stage, Drink Plenty of Fluid, Avoid Alcohol
- Simple analgesia
AVOID Contact sports for 4 wks after having Glandular Fever to reduce the risk of Splenic rupture
Hallmarks of Norovirus ??
Winter vomiting Bug, one of the MCC of Gastroenteritis in the UK
- Non-Encapsulated RNA virus species
- Faeco-Oral Route or Toilet containing infected body fluids (vomit or Faeces) is Flushed
- Isolation of the infected is the crux
Develops within15- 50 hrs of infection
- N & V, Diarrhoea - Headaches, Low-grade fever & Myalgia
Dx.- Hx & Stool culture Viral PCR
Differential Dx. of Norovirus ??
Norovirus: Sudden onset vomiting, short duration of c/f + Contact Hx (+)
Salmonella: Incubation of 6- 72 hrs, contact with contaminated animal product (Unpasteurised egg/ milk), Bloody diarrhoea + High fever
Rotavirus: Similar complaints but MC affects < 5 yrs old
E Coli: Vomiting, Diarrhoea but has longer Incubation 3-4 days to 10 days sever cramping, bloody stools
Hallmark of H1N1 Influenza Pandemic ??
Subtype of Influenzae A virus, MCC of flu in humans
RFs: Chr. illness, Pregnant women, On Immunosuppressants, < 5 yrs old
- Fever > 38 C
- Mayalgia. - Lethargy. - Headache
- Rhinitis. - Sore throat. - Cough
- Diarrhoea & Vomiting
- ARDS (small grp. of pts.)
Rx. of H1N1 Influenzae ??
OSELTAMIVIR (Tamiflu)- Oral drug
- Neuraminidase inhibitor which prevents new viral particles from being from infected cells
- S/E: N & V, Diarrhoea. Headache
ZANAMIVIR (Relenza)
- Inhaled medication. IV also available for pts. who are acutely well
- Neuraminidase Inhibitor
- S/E: Induce Bronchospasm in asthmatics
Hallmarks of Hand, Foot & Mouth Disease ??
Caused by Intestinal viruses
- MC Coxsackie A16 & Enterovirus 71
- Contagious, Outbreaks at nursery
Mild systemic upset: Sore throat, Fever
- Oral ulcer
- Vesicles on Palms & Soles of feet
Rx.- Symptomatic Rx
No need to be excluded from school
- If children unwell, should be kept off school until they feel better
Hallmark of TB ??
M tuberculosis (MCC), M bovis, M africanum
- Pulm. TB: Communicable form
- LNs, CNS, Liver, Bones, GUT, GIT
- Notifiable disease
Mostly affects adults in their most productive years
- 95% deaths occur in developing nation
Strong RFs of TB ??
- Lived in Asia, Latin America, Eastern Europe or Africa for years
- Exposed to infectious TB case
- HIV (20- 30x more likely to develop active TB)
- Immunocompromised
- DM. - Silicosis. - Apical Fibrosis
Symptoms & Signs of TB ??
Cough: Initially dry later productive
Low grade fever
Night sweats- drenching
Anorexia, Malaise-(Noticed in hindsight, after Rx.)
Crackles, Bronchial BS or Amphoric BS (distant hollow BS heard over cavities)
Clubbing if longstanding disease
Erythema Nodosum
Ix. done in suspected TB ??
Isolate
- CXR: Fibro-nodular opacities in upper lobes with/ without cavitations
- Sputum-AFB smear (3 sputum sample)- (+)ve for AFB
- Sputum CULTURE: GOLD Std., Most sensitive & specific; should always be done
- FBC: Raised WBCs, Low Hb
- NAAT on at least 1 of the sample
- Test for HIV in 2 months of Dx.
Classical CXR finding of Reactivated TB ??
Upper Lobe Cavitation
B/L Hilar LNpathy
Rx. of
- Active TB ??
- Latent TB ??
- Meningeal TB ??
First 2 months: RIPE
Next 4 months: RI
3 months of RI (+ Pyridoxine) (OR) 6 months of I (+ Pyridoxine)
12 months regimen + Steroids
Indications of DOT therapy ??
Done 3x a week dosing regimen
- Homeless people with Active TB
- Pts. likely to have Poor concordance
- ALL Prisonors with Active/ Latent TB
How to screen for Latent TB ??
Mantoux test
IFN- Gamma Release Assay- Used when
- Mantoux is (+)ve or Equivocal
- Tuberculin test is FN
Causes of FN Mantoux test ??
Miliary TB
Sarcoidosis
HIV
Lymphoma
Very Young age (eg.- < 6 months)
What is Primary TB ??
Non-Immune host + Exposed to TB => Primary Infection of lungs => GHON Focus (Site: Mid/ Lower Lobes)
- G Focus is composed of Tubercle- laden Macrophages
GHON Complex= G Focus + Hilar LN
In Immunocompetents, initial lesion usually heals by Fibrosis
Immunocompromised can develop disseminated disease (Miliary TB)
What is Post-Primary TB ??
Primary TB is
In < 10% cases => Progressive Primary TB (In Risky individual)
- Progressive Lung Disease => Bacteremia => Miliary TB
In > 90% Heals by Fibrosis, Calcified & PPD (+)ve
- If the host becomes immunocompromised, the initial infection is REACTIVATED => 2nd TB
- Occurs in the APEX of lungs
- FIBROCASEOUS Cavitary lesion
- Bacteremia => Miliary TB
Which part of Lung does
- Primary infection affects ??
- Reactivation affects ??
- Mid or Lower lobes
- Upper Lobes (cause Bacterias are Highly aerobic)
HP of 2nd TB ??
Caseating granuloma with Central Necrosis + Langhans Giant cell (Fused Macrophages)
[LangERhans cell: dERmal APC]
Causes of TB Reactivation ??
Immunocompromised
- HIV, Organ Transplant recipient
TNF-Alpha Inhibitor use
Mantoux Test
0.1 ml of 1: 1000 Purified Protein Derivative (PPD) given Intradermally
- Results read after 2- 3 days
< 6mm: (-)ve No Hypersensitivity to tuberculin protein
- Previously unvaccinated can be given BCG
6- 15mm: (+)ve HS to T protein
- BCG should NOT be given
> 15mm: Strong (+)ve HS to T protein
- Suggests TB infection
Hallmark of BCG vaccine ??
Mycoplasma pneumonia is aka ??
Unreliable in protecting against Pulm. TB
- But it prevents ExtraPulm. TB rather than Pulm. TB
“Walking Pneumonia”
Hallmark of HIV
RNA retrovirus of Lentivirus genus
- HIV-1 & HIV-2
- HIV-2 is MC in West-Africa, has lower transmission rate, less pathogenic with slow progression to AIDS
HIV => Infects CD4, Macrophages, Dendritic cells
GP-120 binds to
- CD4 & CXCR4 on T cells (causes Late infection)
- CD4 & CCR5 on Macrophages (causes early infection)
After Cell entry, Reverse Transcriptase creates dsDNA from RNA for integration into host DNA
Which mutation can give immunity against HIV ??
CCR5 mutation
- Homozygous: Immunity
- Heterozygous: Slower course
Basic structural proteins of HIVirus ??
Diploid genome (2 molecules of RNA)
The 3 structural genes (protein coded for)
1) Env (gp120 & gp41): formed by cleavage of gp160
- gp120: attachment to host CD4+ (Docking gp)
- gp41: Fusion & Entry (Transmemb. gp)
2) gag (p24, p17)
- p24-Capsid & p17-Matrix proteins
3) pol- Reverse transcriptase, Integrase, Protease
How to Dx. HIV ??
HIV-1 or 2 antibody (IgG &/or IgM) + p24 antigen combination assay
If (+)ve, HIV1/HIV2 differentiation assay
- HIV1 (+)ve, HIV2(-)ve: HIV1 infection
- HIV1 (-)ve, HIV2(+)ve: HIV2 infection
- HIV1 & 2 both (+)ve: Both infection
- HIV1 (-)ve or Intermediate, HIV2 (-)ve ==> do [HIV-1 NAT] => If (+)ve => Acute HIV-1 infection or else, (-)ve for HIV-1
Dx. criteria of AIDS ??
CD4+ count: <= 200 cells/mm3
- Normal 500- 1500 cells/mm3
(OR)
HIV (+)ve + AIDS-defining condition
Diseases reactivated in HIV when the CD4+ cell count < 500 cells/mm3 ??
Candida albicans (Oral thrush)
EBV (Oral Hairy Leukoplakia)
HHV-8 (Kaposi Sarcoma, Local Cutaneous disease)
HPV (Sq. Cell CA at sites of sexual contact - Anus, Cervix, Oropharynx
TB (Latent TB)
Diseases seen CD4+ is < 200 cells/mm3 in HIV ??
1) Histoplasma Capsulatum
- Oval Yeast cells in Macrophages
- Fever, Wt. loss, Fatigue, Cough, Dyspnoea, N & V, Diarrhoea
2) HIV
- Dementia (Cerebral atrophy)
- HIV-associated Nephropathy
3) JC Virus reactivation
- Progressive Multifocal Leuko-Encephalopathy: Demyelination on MRI
4) HHV-8: Kaposi S, Disseminated disease (Resp., GI, Lymphatic)
5) Pneumocystis jirovecii
Diseases seen when CD4+ < 100 cells/mm3 in HIV ??
1) Bacillary Angiomatosis
- Bartonella sp., Multiple red purple papules/ nodules
- Biopsy: Neutrophillic inflammation
2) ESOPHAGITIS
- Candida albicans
3) CMV
- CREEP- Colitis, Retinitis, Esophagitis, Encephalitis, Pneumonitis
4) C NEOFORMANS (Meningitis)
- Encapsulated yeast on India ink or Capsular antigen (+)ve
5) CRYPTOSPORIDIUM Sp.
- Chronic, Watery diarrhoea
- Acid Fast Oocytes in stools
6) EBV- B-lymphoma (NHL,CNS- lymphoma
7) MAC & MA-intracellulare
8) TOXOPLASMA GONDII: Brain abscess
- Multiple ring enhancing lesion
HIV & Pregnancy
AIM: Reduce complication to mum & baby, minimize Vertical Transmission
- ART to All pregnant women regardless of whether they were taking it before
VAGINAL Delivery if Viral load < 50 copies/ml at 36 wks POG
C-section: IV Zidovudine started 4 hrs before beginning
Breastfeeding is CI
Neonatal ART ??
Indicated if Maternal Viral load < 50 copies/ml
- Zidovudine (Orally) or
- Triple ART used
Continued for 4- 6 wks
What factors reduce risk of Vertical Transmission ??
Reduces from [25- 30% to 2%]
- Maternal ART
- Mode of Delivery (C- section)
- Neonatal ART
- Infant Bottle Feeding
CMV Retinitis Rx ??
CD4+ count < 50
DoC: IV Ganciclovir
- Can be stopped once CD4+ > 150
IV Foscarnet or Cidofovir
Hallmark of Kaposi Sarcoma ??
HHV-8
- Purple papules or Plaques on skin & mucosa (eg.- GIT, Resp.)
- Skin lesions can ulcerate
- Resp.- Massive Haemoptysis & Pleural effusion
Rx.- RT + Resection
Hallmark of Rabies ??
Viral disease that causes Acute Encephalitis
- RNA Rhabdovirus, specifically Lyssavirus : BULLET Shaped Capsid
- Dog bites (major), Bat, Racoon & Skunk
Virus => travels up Nerve AXONS => CNS
Features of Rabies infection ??
Headache, Fever, Agitation
Hydrophobia (H2O provokes Muscle spasms)
Hypersalivation
NEGRI Bodies: Cytoplasmic inclusion bodies found in Infected Neurons
Rx. of Rabies
No risk of developing rabies after Animal bits in UK & other majority developed nations
After an animal bite
- Wash wound with soap & H2O
- If already Immunized- 2 further dose of vaccine given
- If NOT previously vaccinated: Full Course & if possible, should be given locally around the wound
If NOT Treated : FATAL
Hallmark of Tularaemia ??
F tularensis, zoonotic infection
- Vector: Lagomorphs suh as Rabbits, Hares, Pikas, Aquatic rodents- beaver, muskrat & ticks
- Erythematous papulo-ulcerative lesion at bite site
- Reactive, Ulcerating Regional LNpathy
Rx- Doxycycline
Which Abx. promotes acquisition of MRSA ??
Ciprofloxacin
Resistance is mediated by necA gene which encodes for an altered Penicillin-Binding-protein
Aciclovir MoA ??
DNA Polymerase Inhibitor
- More specific for viral than mamamalian DNS Polymerase
IoC for Chlamydia ??
Lancefield grouping is used in ??
Prophylaxis of N meningitidis ??
NAAT
Organisation of Streptococci
DoC: Single dose Ciprofloxacin
Rifampicin: 1 tab., BD for 2 days
Most likely presentation of Staph. aureus food poisoning ??
How to prevent Norovirus spread in a care home ??
Severe N & V
- due to Enterotoxins A-E
Handwashing with soaps & warm H2O before & after contact with those infected
- Alcohol gels are less effective
How to differentiate b/w Lymphoma & Toxoplasmosis ??
Thallium SPECT; if (+)ve result= CNS Lymphoma
due to its limited availability Rx is started empirically on the basis of Scoring System
- Toxoplasmosis IgG in the serum
- CD4+ < 100 & Not receiving Prophylaxis for Toxoplasmosis
- Multiple ring enhancing lesions on CT or MRI
Retro-orbital pain/headache + Fever + Facial flushing + Rash + Thrombocytopenia + Returning traveller ??
Dengue fever
(HIV seroconversion take >= 2 wks after exposure)
What makes Plasmodium knowlesi infections particularly dangerous ??
Shortest Erythrocytic Replication (24 hrs) Cycle ==> High parasite counts in a short period of time
- Plasmodium sp. have 2 reproductive cycles: Exo-Erythrocytic cycle (Hepatocytes) & Erythrocytic cycle
SEVERE Parasitemia in P Knowlesi is > 1%
Early ring trophozoites & late trophozoites in blood film
Orf ??
aka Contagious Ecthyma
- Zoonotic infection caused by PARAPOXVIRUS
- Sheep & Goat farmers
Type of bacteria
- N meningitidis
- S pneumonia
- E coli
- H influenzae
- L monocytogenes
- Gram (-)ve Diplococci
- Gram (+)ve Diplococci
- Gram (-)ve bacilli
- Gram (-)ve Coccobacilli
- Gram (+)ve Rods
UTI symptoms + Urine leucocytes (+)ve + Nitrites (-)ve
- Causitive organism ??
Staph. Saprophyticus
- Gram (+)ve can’t reduce Nitrate to Nitrite for energy
- Gram(-)ve organisms test (+)ve on Nitrites as they convert Nitrate to Nitrites for energy
Man returns from trip abroad + Maculo-papular rash + Flue like illness (Sore throat, fever, LNpathy, Myalgia, Diarrhoea, mouth ulcers,) ??
HIV Seroconversion
Traveller’s Diarrhoea MCC ??
Rx. for C Jejuni diarrhoea ??
E coli
Its a Self-limiting infection, but if Severe, then Rx. with CLARITHROMYCIN is indicated
MC complication of Gonorrhoea ??
Infertility secondary to PID
Infective exacerbation of COPD cause ??
Moroxella Catarrhalis
Disease caused by HTLV-1 ??
Adult T cell Leukaemia/Lymphoma & HTLV-1 associated Myelopathy/ Tropical Spastic Paraparesis
Pruritic rash on Buttock or Ankle & Soles + Catalonia
S stercoralis
