Respiratory tract infections Flashcards
1
Q
Pneumonia When how frequent background
A
significant proportion of workload in the community and hospital, especially in Winter (UK GPs 10-20% of patients; Hospital 30,000 admissions/yr & 30% of HAI) •Also contributes to lost working days •Pneumonia is a major contributor to death in patients with debilitating diseases
2
Q
main bacterial pathogens in the respiratory tract
A
•Gram positive cocci:
–Streptococcus pneumoniae (‘pneumococcus’) – sinusitis, OM, exacerbation COPD, pneumonia
–Staphylococcus aureus – sinusitis, OM, post-influenza pneumonia, lung abscess
– Strep pyogenes (=Group A Strep) Sore throat
•Gram positive rods:
–Corynebacterium diphtheriae - Diphtheria
•Gram negative rods:
–Haemophilus influenzae - sinusitis, OM, exac.COPD, pneumonia
–anaerobes e.g. Bacteroides - sinusitis, lung abscess, dental
–Legionella pneumophila - Legionnaires’ disease
–Coliforms & Pseudomonas – ‘Opportunist’ & hospital-acquired pneumonia
•Acid fast bacilli:
–Mycobacterium tuberculosis (TB)
3
Q
Other bacteria in the respiratory tract
A
- Gram positive cocci: viridans streptococci (commensals);
- Gram positive rods: ‘diphtheroids’ (commensals);
- Gram negative cocci: Moraxella (occ. pathogen), Neisseria spp (commensal but NB N. meningitidis)
- Gram negative rods: Bordetella pertussis (whooping cough);
- Acid fast bacilli: Mycobacterium avium complex (MAC), Mycobacterium kansasii
- Other species: Mycoplasma pneumoniae, Chlamydophila (Chlamydia) pneumoniae, Chlamydia psittaci
4
Q
Fungi in the resp tract
A
- Yeast – Candida (oral candidosis)
- Yeast – Cryptococcus (occ. pneumonia [+meningitis] in AIDS)
- Aspergillus (sinusitis, invasive aspergillosis disease in leukaemics)
- Mucor (mucormycosis - destructive sinusitis)
- Histoplasma (histoplasmosis - tropical)
- Pneumocystis (pneumonia in AIDS)
5
Q
rare respiratory pathogens
A
Nocardia (lung & CNS abscesses)
- Bacillus anthracis (skin & pulmonary anthrax)
- Actinomyces (oral/lung/uterine actinomycosis)
- Others: Coxiella burnetii (Q fever), Melioidosis, coccidioidomycosis etc
6
Q
Causes of PHARYNGITIS
A
Cause by: ** Viruses (70+%) Bacteria (10-30%)**
streptococcal sore throat
- Caused by Streptococcus pyogenes (Gp A strep, ß-haemolytic s) [Strep types C & G - sore throat]
- Carriers 1 to 5% esp children; causes 15 - 30% of sore throats
- Difficult to distinguish from viral, clinically but can be more severe, with lymphadenopathy, feels generally unwell
- Penicillin V often given, or amoxicillin – may reduce duration and the complications (glomerulonephritis, rheumatic fever, scarlet fever)
•NO resistance to penicillin
•Erythromycin or clarithromycin an alternative – but NB 10% resistance
7
Q
Rheumatic fever
A
•Strep pyogenes pharyngitis, any type, 5 - 16 y old up to 30 y. 2-3 w after.
- Major manifestations: arthritis (flitting polyarthritis, larger joints), carditis, chorea, rash (erythema marginatum), nodules.
- Minor: fever, previous episode, raised ESR/CRP, ECG abnormalities, arthralgia
- Aschoff bodies in heart (10% carditis), prolonged P-R interval, murmurs
- ASO ASB titres, throat swab, ECHO (may be nodules on valves)
8
Q
Glomerulonephritis
A
•Strep pyogenes pharyngitis or skin infeciton, 1-5 y old. 10-14 days after. Certain Griffiths types
•Abrupt fever malaise loin pain, oedema of feet & face, haematuria & proteinuria , oliguria
- Impaired renal function
- Almost always resolves without specific treatment
•Immune complexes in glomerular basement membrane
•Other causes: hepatitis, EBV, atypical pneumonias etc; drugs
9
Q
Scarlet fever
A
•Mostly secondary to pharyngitis (can be ‘surgical scarlet fever’ – wound; due to erythrogenic toxin A B or C (Streptococcal Pyrogenic Exotoxins). Probably synergy with other strep toxins. 10% GAS produce them
•Incubation 2 to 4 d.
- Onset: sudden fever; rash follows 12-48 hours after the fever
- Prodrome: sore throat, fever, headache, vomiting, abdominal pain, myalgia, tachycardia with the fever. Rash neck first, chest & scapular regions. Trunk and legs later.
- It has a coarse texture like sandpaper, punctate on a diffuse erythematous base
- Circumoral pallor
- Rash for several days; may appear more prominent in skin creases with confluent petechiae esp axillae and groin “Pastia’s lines”.
- Skin desquamation
10
Q
DIPHTERIA
A
Caused by Corynebacterium diphtheriae var gravis, intermedius or mitis
Laryngeal, pharyngeal, rare – nasal, skin
Resp tract obstruction, myocarditis, neuropathy (cranial nerves, peripheral)
Clinical diagnosis first, then swabs
C. diphtheriae causes disease by producing diphtheria toxin
Treatment: Airway, anti-toxin, penicillin or erythromycin
11
Q
QUINSY (peritonsilar abscess)
A
Mixed organisms esp. anaerobes, Staphylococcus aureus & oral flora.
Presents as increasing discomfort on swallowing, unilaterally enlarged tonsil. Clinical diagnosis only.
Treatment: Antibiotics e.g. co-amoxiclav (‘Augmentin’) and stick the point of a taped scalpel in it (after a bit of anaesthetic spray).
12
Q
other infections presenting with pharyngitis
A
Haemophilus influenzae capsulate type b causes very rapid, life-threatening epiglottitis in young children. Respiratory obstruction occurs in hours. Rare now because of Hib vaccine.
Treat cefotaxime or ceftriaxone stat, or chloramphenicol, plus call an anaesthetist
13
Q
RARE causes of pharyngitis
A
- LEMIERRE’S DISEASE (anaerobic pharyngitis plus septicaemia in adolescents);
- RETROPHARYNGEAL ABSCESS;
- VINCENT’S ANGINA (acute necrotising ulcerative gingivitis);
- GONOCOCCAL PHARYNGITIS;
- CHLAMYDIAS & MYCOPLASMAS & YERSINIA.
- Candida NB non-infectious causes e.g neutropenia, Bechet’s disease, SLE.
14
Q
INFECTIONS AT SITES ASSOCIATED WITH THE URT
sinusitis
A
- Viral URTI leads to temporary cilial defect or direct mucous membrane damage. Blockage of ostium esp. maxillary sinuses. Diving & allergy also lead to sinusitis.
- Pain headache purulent discharge; occasional facial cellulitis as well, in children.
- Organisms: Haemophilus influenzae, pneumococcus, anaerobic streptococci, Moraxella catarrhalis
- Diagnosis – mostly clinical
- Treat – amoxicillin or Augmentin or Erythro
- Complications: Frontal sinusitis leading to cerebral abscess - often a strep (e.g. Strep milleri) +/- anaerobes
15
Q
otitis media
A
Fluid in middle ear, with symptoms (pain, hearing loss, fever, lethargy, irritability; red and bulging tympanic membrane).
20% of all children under 5 y have an episode of middle ear infection. Less common in adults.
Risk of recurrence; repeated attacks may lead to permanent hearing loss.
- Organisms: mainly Haemophilus influenzae and Streptococcus pneumoniae, also Moraxella, Streptococcus pyogenes (group A streptococcus), Staph aureus.
- Diagnosis – mostly clinical
- Treat – amoxicillin or Augmentin or Erythro
•Complications… meningitis esp. pneumococcal
16
Q
Otitis externa
A
Irritation and suppuration of the external auditory meatus, sometimes with pain
•Organisms: mainly Staph aureus; also Group A strep; occasionally Pseudomonas (swimmers) and fungi.
–If pneumococcus & haemophilus isolated – probable tympanic membrane rupture from otitis media
- Diagnosis – mostly clinical, plus a swab
- Treat – cleansing & ear drops, flucloxacillin if Staph aureus
- ‘Malignant otitis externa’ Pseudomonas – rare severe invasive otitis, necrotising, can spread to temporal bone, life threatening: mainly diabetics, immunocompromised.
17
Q
MAstoidits
A
- Now quite rare in the post-antibitoic era
- Severe infection of mastoid follows otitis media
- Hearing loss pain and fever then swelling redness and tenderness over the mastoid bone
- May be associated with tympanic membrane perforation and discharge of pus
- X-ray
- Same organisms and treatment as for otitis media but always antibiotics
- If a prolonged course- may be Gram negs e.g. coliforms
18
Q
Laryngitis to bronchits and things inbetween
A
•Acute exacerbation of chronic bronchitis
Often in wintertime, may progress to pneumonia
Streptococcus pneumoniae, Haemophilus, Mycoplasma
Sputum colonised long-term, becomes purulent
GPs use amoxicillin, tetracycline, Augmentin, erythro
• Bordetella pertussis - whooping cough – NB lung damage, early erythromycin, prophylaxis for sibling, vaccine
19
Q
Bordetella pertusis
A
- The incubation period is on average 7-10 days (range from 5-21 days) and the infectious period is for 21 days after the onset of symptoms.
- Highest incidence - infants. Young infants: severe complications, hospitalisation and death. Adults and older children can be source of infection.
- Protection not life-long, individuals can get re-infected and spread infection to others.
- After whooping cough vaccination, infection in fully vaccinated individuals is normally very mild.
Early stage – like a cold. 1-2 weeks
- Paroxysmal stage - intense bouts of coughing, thick sputum
- a ‘whoop’ sound with each sharp intake of breath after coughing; vomiting after coughing, especially in infants and young children
- tiredness and redness in the face from the effort of coughing
•Diagnosis: clinical + pernasal swab; PCR; serology
20
Q
isolating bordatella pertusis for culture
A
A fastidious, gram-negative bacterium requiring special media for isolation.
21
Q
•B. pertussis produces multiple antigenic and biologically active products including:
A
- Pertussis toxin
- Filamentous hemagglutinin (FHA)
- Agglutinogens
- Adenylate cyclase
- Pertactin
- Tracheal cytotoxin
The bacteria attach to the cilia of the respiratory epithelial cells, produce toxins that paralyse the cilia, and cause inflammation of the respiratory tract, which interferes with the clearing of pulmonary secretions.
•Until recently, it was thought that B. pertussis did not invade the tissues; however, recent studies have suggested that the bacteria are present in alveolar macrophages.
22
Q
Tx of B. pertussis
vaccines
A
Treatment & prophylaxis: macrolides e.g. erythromycin, clarithromycin, azithromycin
•Vaccine: older whole-cell, newer subunit ‘acellular’ combined with other vaccines
23
Q
UK immunisation schedule
A
•2 months
5-in-1 (DTaP/IPV/Hib) vaccine –diphtheria, tetanus, whooping cough (pertussis), polio and H. influenzae type b; Pneumococcal conjugate vaccine (PCV) ; Rotavirus vaccine.
•3 months
DTaP/IPV/Hib – 2; Meningitis C, Rota – 2
•4 months
DTaP/IPV/Hib – 3; PCV-2
•Between 12 and 13 months
Hib/Men C booster; Measles, mumps and rubella (MMR) vaccine; PCV-3
- Later years: various boosters
- 65 and over
Flu (every year); Pneumococcal (PPV: not conjugate) vaccine
•70 years
Shingles vaccine
24
Q
TReatment of CA pneumonia
Home or admitted to hospital (but not severe, social/other admission with CAP, or no previous therapy)
A
Amoxicillin 0.5g-1.0g tds
OR Erythromycin
OR Clarithromycin
OR Doxycycline
25
TReatment of CA pneumonia NOT SEVERE
IN HOSPITAL
Amoxicillin **AND** [Erythromycin OR Clarithromycin OR Doxycycline]
Note: Hospitals tend to use amox + doxycyline because macrolides promote MRSA by selection. Modify therapy if blood cultures etc positive.
26
SEVERE CAP treated in HOSPITAL
•Co-amox 1.2g tds… **IV** _AND_ Doxycycline **orally** OR Erythromycin OR Clarithromycin **IV**
Can _ADD_ **Rifampicin** if severe *Legionnaires’ disease* OR Levofloxacin 0.5 g od plus Ben Pen 1.2 g qds
27
•Early HAP or Aspiration pneumonia e.g. post-op chest infection/pneumonia
AS FOR CAP
28
Late HAP or Late Aspiration pneumonia
Piperacillin-tazobactam [‘Tazocin’], plus dose of gentamicin if severe sepsis/shock
•Severely compromised patients - case by case management
29
When bacteria idnetified.. ABX:
## Footnote
* Pneumococcus -
* Staph aureus -
* Haemophilus -
* Anaerobes –
* Coliforms, Pseudomonas –
* Legionella –
* ‘Atypicals’ Mycoplamsa, chlamydia -
* TB –
* Aspergillus –
* Pneumococcus - Penicillin (NB can be Pen-R)
* Staph aureus - Flucloxacillin (NB MRSA)
* Haemophilus - Amoxicillin [or co-amoxiclav or cephalosporin]
* Anaerobes – Metronidazole
* Coliforms, Pseudomonas – check sens
* Legionella – Erythromycin plus rifampicin OR cipro
* ‘Atypicals’ Mycoplamsa, chlamydia - tetracycline
* TB – RIPE - rifampicin, isoniazid, pyrazinamide & ethambutol (NB MDR strains)
* Aspergillus – Amphotericin B
30
common bacteria for pneumonia
Streptococcus pneumoniae (pyogenes)
–Haemophilus influenzae
–Staphylococcus
–Anaerobes (aspiration)
31
uncommon bacteria for pneumonia
–Gram negative bacilli
(from the bowel: Klebsiella pneumoniae, E. coli, Pseudomonas aeruginosa, Acinetobacter)
–Nocardia asteroides/brasiliensis
–Actinomyces –Moraxella catarrhalis
32
very uncommon bacteria for pneumonia
–Yersinia/Pasteurella pestis (plague)
–Pasteurella multocida
–Francisella tularensis
–Bacillus anthracis (anthrax)
–Brucella (brucellosis)
33
Sx of pneumonia
* Intense fever
* rigors,
* excruciating pleuritic pain,
* tachycardia,
* tachypnoea,
* cough,
* rust coloured sputum
* o/e crackles, later lobar consolidation & reduced air entry
* Blood cultures 10-20% positive without antibiotics
* Fever breaks on 8th day
34
features of atypical pneumonia
* Progressive onset
* Fever without rigors
* Cough without sputum
* Headache, muscle pains
* Diffuse chest crackles
* Modest leukocytosis
* Diffuse infiltrates on CXR
35
nycoplasma pneumoniae
–Small epidemics, particularly in closed populations
–10-20 days incubation
–Cough, fever, malaise
–Arthralgia, middle ear infection (bullous myringitis), diarrhoea and vomiting, haemolytic anaemia, lymphadenopathy, meningitis, hepatitis, pericarditis
–CXR lower lobe infiltrates resolve over 4-6 weeks
36
chlamydia pneumoniae
–Causes ornithosis in domestic fowl (canaries, parakeets, pigeons, turkeys)
–Atypical pneumonia with 7-14 day incubation
–Fever, arthralgia, headache, myalgia, breathlessness, pleuritic pain
–Splenomegaly
–Macular rash
–CXR lower lobe infiltration
37
legionella pneumonia
–Breed in water and air conditioning systems
–Transmitted through conditioned air but not between humans
–Disease ranges from mild and barely noticed to fever, rigors, headache, pneumonia with haemoptysis and chest pain
–Numerous extrapulmonary symptoms: abdominal pain, diarrhoea, hyponatraemia, myalgia, confusion, skin rash, oliguria, proteinuria, fits, hepatitis, neutropenia, lymphopaenia
–CXR dense general consolidation, often unilateral, pleural effusion
–Typically in small epidemics (the Order of Buffalos
38
Coxiella burnetti pneumonia
–Rickettsiaceae: Q fever
–Tick vector
–Infects various wild and domestic animals (cattle, sheep goats) often asymptomatically
–Multiplies in placenta of pregnant animals and released at birth, e.g. calving
–Atypical pneumonia with 2-4 week incubation period
–Abrupt onset of fever, chills, myalgia, headache
–Hepatosplenomegaly
–CXR dense nodular infiltrates
39
Criteria for hospitalisation
* Rick factors for pneumonia
* Failure of first line antibiotic therapy
* Signs of immediate severity
–Chest pain
–Confusion, drowsiness
–Heart rate \>125 bpm
–Temperature \<35C or \>40C
–Respiratory rate \>30/min
–Cyanosis
–Blood pressure \<90/60 mmHg
* Suspected complication (pleural effusion, cavitation etc)
* Home management appears impossible (pain, vomiting, lives alone, no fixed abode, mental illness)
40
Poor prognostic factors in pneumonia
## Footnote
* Age \>65 yrs
* Co morbidity: COPD, heart disease, diabetes, stroke
* Respiratory rate \>30/min
* Confusion (abbreviated mental test score \<8)
* Blood pressure \<90 systolic and/or 60 diastolic
* Hypoxaemia \<8 kPa
* Urea \>7 mM
* Albumin \<35 g/l
* WBC count \>20 or \<4 x 109/l
* CXR bilateral or multilobar involvement
* Positive blood culture
41
CURB-65 score
* Confusion (AMTS\<8)
* Urea \> 7 mM
* Respiratory rate \> 30/min
* Blood pressure systolic \< 90 and/or diastolic \< 60 mmHg
age \>65
Mortality is 83% with all 4 CURB factors, 33% 3, 23% 2, 8% 1, 2.4% none.
42
Principles of Treatment for pneumonia
* Oxygen: aim for oxygen saturation \> 92%: watch for tiring and rising PaCO2
* Encourage fluids (intravenous if necessary) and watch urine output
* Plenty of analgesia
* Adequate nutrition
* Assess poor prognostic factors and CURB score, and need for ITU transfer early
43
Treatment failure
•**CRP should fall by \>50% within 4-5 days**; if not consider treatment failure or complication
_•Causes of treatment failure:_
–Wrong diagnosis (PE, carcinoma, bronchiectasis, pulmonary oedema, eosinophilic pneumonia, foreign body aspiration, vasculitis, drug induced, COP)
–Secondary complication (effusion, empyema, abscess, ARDS)
–Wrong antibiotics, unexpected pathogen, antibiotic resistance, TB or fungal infection
–Impaired immunity (general or caused by co morbidity such as bronchiectasis
44
Follow up after penumonia
* CXR changes take 6-12 weeks to resolve (longer in elderly)
* Repeat CXR advised at 6 weeks especially for persistent symptoms or if possible underlying lesion suspected (smokers, age \>50 yr)
* FOB may be necessary
* 10-20% of smokers \>60 yr treated as inpatients or outpatients for CAP have underlying carcinoma
* Vaccination
–Influenza: chronic disease, diabetes, age \>65 yr, health care workers (care with egg allergy); protects ~60% depending on “strain of the year”
–Pneumococcal: splenectomy, chronic disease, diabetes, immunosuppression; avoid in pregnancy
45
VIRAL PNEUMONIA: COMMON CAUSES
VIRAL PNEUMONIA: COMMON CAUSES
•**Influenza A,B**
–genetic rearrangement in animal reservoirs
–At least 50% of all viral pneumonia
–Pandemics with excess mortality of 10,000 patients/year or more
–Some post-viral pneumonia is caused by secondary bacterial infection
•**Varicella/zoster (chickenpox)**
–Rash on face then body; erythematous macules then vesicles which become pustular then crust; pneumonia within 5 days of rash
–Epidemics in winter and spring
–Pneumonia almost exclusively in adults
46
VIRAL PNEUMONIA: LESS COMMON CAUSES
VIRAL PNEUMONIA: LESS COMMON CAUSES
**•Parainfluenza**
* **–3 serotypes:** *1,2 croup; _3 pneumonia_*
* –Children –*_Infrequent in adults unless immunosuppressed_*
**•Respiratory syncytial virus (RSV**)
* **–Leading cause of respiratory tract infection in children**; 25% of hospital admissions for pneumonia; 75% of bronchiolitis in children \< 6 months; epidemics in autumn and spring; all children infected
* –Cough, cold, pharyngitis, fever; **lower respiratory tract involved in 50% cases**
* –Pneumonia or bronchiolitis
* –Immunosuppressed
* –**Induces IgE** response which **predisposes to asthma**
**•Measles**
* *–Prodromal (fever, URTI, malaise, anorexia) 1 week before rash;* **50% develop pneumonia**
* –Face, neck, extremities
* –**Leukopenia**
* –**Reticulonodular pulmonary infiltrates, hilar lymphadenopathy, pleural effusion**
* –_Immunosuppressed_
**•Adenovirus**
–5% respiratory infections in children, 2% adults
**•Hantavirus**
* –Americas
* –**Rodent** (filed mouse, chipmunk, vole) reservoir
* –**_Caught from faeces, never person to person_**
**•Cytomegalovirus**
47
Lung abscesses
* Single or multiple,
* acute or chronic,
* primary or secondary
* High mortality
* Alcoholic men aged \>50 yr
Most result from **aspiration pneumoniae**: dental disease, impaired consciousness, diabetes, bronchial carcinoma, secondary to Staph. pneumonia, immunocompromised, septic embolism in intravenous drug abusers
Cough, haemoptysis, fevers, night sweats, weight loss, malaise, foul sputum
Culture blood, sputum, BAL, needle aspirate (CT or USS guided) CXR, CT to exclude foreign body, underlying neoplasm
48
ASPERGILLUS LUNG DISEASE
(1) Exacerbation of asthma
2) Exuberant IgE production leading to pulmonary eosinophilia and
3) Allergic bronchopulmonary aspergillosis (ABPA)
4) Invasive aspergillus pneumonia
5) Aspergilloma
6) Extrinsic allergic alveolitis
49
Allergy and asthma
–IgE response, also IgG (precipitins)
–High total serum IgE (\>1000 IU/ml)
–Positive skin prick test, precipitins
–Anti-fungals?
50
ABPA
–As above with bronchiectasis
–Flitting lung infiltrates
–Hyphae (not just spores) in sputum
–Dark mucus plugs (airway casts)
–Poorly controlled, sever chronic asthma
–Itraconazole 200 mg bid 4 months
51
Invasive aspergillosis
–Fungal hyphae invade tissue
–Usually always in severely immunosuppressed, chronic oral corticosteroid usage
–Fever, chest pain, cough, haemoptysis, dyspnoea
–Spread to sinuses, brain, eyes, skin, endocarditis
–Fungal hyphae in sputum, induced sputum, BAL, transbronchial biopsy
*–Amphotericin B (poor response rate), itraconazole, voriconazole, caspofungin*
52
Aspergilloma
ASPERGILLOMA
* Ball of fungus in an old cavity
* (TB, sarcoidosis, abscess, tumour, cystic fibrosis)
* Often asymptomatic
* 75% present with haemoptysis
* Itraconazole some help
53
other endemic mycoses
**Histoplasmosis **
–Bat/bird droppings, Midwest and SE USA, mycelia form inhaled
–Mostly asymptomatic, calcified nodules, EAA type syndrome, chronic progression/cavitation in COPD, dissemination in immunocompromised
**•Blastomycosis** –Spores form contaminated soil, USA
**•Coccidioidomycosis**
** •Cryptococcosis**
** •Candida**
54
Bacterial meningitis Dx
Pointers to diagnosis in adults
POINTERS TO DIAGNOSIS (adults)
Fever, headache, meningism, altered mental state
Underlying predisposing illness
Any abnormal CSF cell count (\>5 lymphocytes/cu.mm; any neutrophils)
As for meningitis plus seizures, early mental state changes inc. behavioural
Often a slower onset
May need to cover empirically
55
UK meningitis epidemiology
~950 cases ABM/yr
600 meningococcus (850 sept .+ menin.]
250 pneumococcal
40 Staph aureus
20 Listeria
15 Mycobacterium tuberculosis
10 E. coli & 10 Strep pyogenes
PLUS – many infections associated with neurosurgery
56
Poitners to aetiology in meningitis
What do these idicate?
Rash
Recent ear/sinus.mastoid disease
Neuro signs
Underlying illness, PMHx
Age
Rash 50% meningo sept., 10% pneumo/Hib; viral
Recent middle ear/sinus/mastoid disease (pneumo & haemophilus, anaerobic abscess]
Focal neurological signs (TB, HSV, abscess]
Underlying illness (esp. HIV); head injury; neurosurgery
57
Pointers to aetiology of meningitis in
ADULT previously well
* **Neisseria meningitidis**
* **Streptococcus pneumoniae**
* Viral: **enteroviruses, mumps**, adenovirus, **HSV** etc
RARE: Listeria, Haemophilus influenzae, leptospirosis, TB, coliforms, syphilis, rickettsiae, arboviruses
Structural: abscess, parameningeal focus
Non-infective: malignancy etc
58
pointers to aetiology in adult with significant PMHx
what if neutropenic?
tropical risk..
As for healthy adult PLUS
* **Coliforms, Pseudomonas** (_*neutropenic*, neurosurgery)_
* Staph aureus, Coag neg staph, + above (_neurosurgical_ inc. shunts/drains]
* Cryptococcus, CMV, Aspergillus, Toxoplasma, Nocardia , mycobacteria _(transplant, AIDS, steroids etc_]
Additional tropical risk: **Strongyloides, Schistosoma, cysticercosis**
59
pointers to meningitis aetiology for child that is healthy
Neonate/ older child
if has PMHx
NEONATE: **Strep agalactiae** (Group B strep), E. coli , Listeria, HSV, Toxoplasma, CMV.
OLDER: Neisseria meningitidis, Streptococcus pneumoniae, [Haemophilus influenzae]
significant PMH \>\> as for adults
60
Non-infective DDx for meningitis
* subarachnoid haemorrhage
* carcinomatosis, lymphoma, CNS tumour etc
* SLE & other autoimmmune
* Drug & chemical reactions
* Post-infectious syndromes
61
Admit ?meningitis IF
Any of the following:
1. signs of meningeal irritation
2. impaired conscious level
3. a petechial rash
4. febrile & a convulsion
5. ill/headache & contact of meningococcal disease
62
STAT treatment for all ABM after any initial resuscitaiton
_recommend GP_ to give **1.2 g Ben Pen IV**
or
1g cefotaxime or 1 g ceftriaxone [or 1g chloramphenicol]
_recommend in A & E:_
1. blood for **coag screen**, **culture,** **EDTA for PCR**
2. **_then_ give antibiotic treatment 1st dose**
3. CT scan _then_ LP _if suspicion of raised ICP_
4. throat swab, skin lesion swab (urgent to lab)
63
ANTIBIOTICS: FIRST DOSE
typical meningo rash
**2.4g Ben Pen _IV_**
**_4 hrly_**
64
no typical rash & 18-50 y
## Footnote
ANTIBIOTICS: FIRST DOSE
meningitis
**2g cefotaxime 6 hrly**
OR
**2 g ceftriaxone 12 hrly**
65
Antibiotics first dose:
DELAYED LP or Pen-resistant Pneumococcis risk
ADD **vanc or rifamp** to **_cephalosporin_** (d/w Micro)
_\>50_ y
consider adding *Ampicillin or Amox 2g 4 hrly*
66
meningitis
ANTIBIOTISC FIRST DOSE IF
ANAPHYLAXIS TO BETA-LACTAMS
**Chloramphenicol + vancomycin**;
+cotrimoxazole for \> 50y
67
Other actions on DAY 1
with meningits
and OTHER THERAPIES
* Inform CCDC urgently
* Prophylaxis issues
* Infection control
* Adjunctive therapies (e.g. **steroids: if poss, before or with antibiotic**): _impaired conscious level, focal neuro signs, v. high LP pressure, abnormal CT,_ TBM, Haemophilus & ?Pneumococcus
OTHER THERAPY
* Fluids: euvolaemia
* Immunotherapy - none
* ICU, cardiovascular, renal, neuro & respiratory management
* Advice to patient e.g. support groups; expected prolonged headache;
* audiometry & other OPD neuro review; driving, family history or recurrent meningitis (complement etc) studies
68
Meningococcal meningitis
* **Gram Negative cocci in pairs (‘diplococci’)**
* **Asymptomatic carriage** in upper respiratory tract in up to **20% populatio**n
* Host/bacterial factors leading to blood/meningeal invasion poorly understood.
* *Protection mediated by type-specific antibody to capsular antigens*
* Young children, susceptible adolescents most at risk
* Abrupt onset
* Often accompanied by the **haemorrhagic, non-blanching skin rash of meningococcal septicaemia**
MENINGOCOCCAL MENINGITIS/SEPSIS?
* GP should **initiate antibiotic treatment before hospital transfer.**
* **i.v. Ceftr/Cefot/Penicillin/Chlo**r
* Culture/PCR confirmation
* **Prophylaxis for family/close contacts to eliminate nasopharyngeal carriage.**
* Depending on antibiotic Rx given, the patient *may also require Rx to eliminate carriage after acute phase*
69
LESS ACUTE/INSIDIOUS ONSET CNS INFECTIONS
LESS ACUTE/INSIDIOUS ONSET CNS INFECTIONS
* TB meningitis\* More common in immunocompromised host
* Cerebral malaria
* Spongiform encephalopathy (eg vCJD)
* SSPE – measles virus
* Sub-acute sclerosing panencephalitis
70
TB meningitis
* **CNS spread from extra-CNS focus**, \>50% assoc with miliary TB
UK: most cases in adults
* **Typically insidious\*** onset:
* Apathy, malaise, anorexia progressing over several weeks
meningism
altered level consciousness
Need high index of suspicion in aseptic meningitis and empiric Rx pending lab diagnosis.
* **_Always take a simultaneous sample for blood glucose when you do an LP_**
71
MICROBIAL COMPONENTS THAT TRIGGER SHOCK
* Endotoxin (LPS) (Gram negatives)
* Lipoteichoic Acid (Gram positives)
* Direct - vascular endothelium
Indirect
* Toll-like receptors
* Complement cascade
* Coagulation cascade etc. (via cytokines IL–1, IL– 6, TNF etc
* Depletion of protein C
72
Main Causes of Infection – related shock and mortality
Main Causes of Infection – related shock and mortality
**(a) Gram negative bacteria**
E. coli, other coliforms, meningococci, Pseudomonas, Haemophilus (mort. 30% - 50%)
**(b) Gram positive**
Staph aureus, Group A Streptococci, Strep pneumoniae, Clostridium spp. (mort. 20% - 30%)
_NB neonatal sepsis:_ Gr B strep, Listeria, E. coli
**(c) Parasites**
Malaria (mort. \< 10%)
**(d) Fungi**
Candida (mort. 20%)
**(e) Viruses**
Viral haemorrhagic fevers (mort. 50%)
73
Most common conditions associated with septicaemia and shock
Most common conditions associated with septicaemia and shock
* Severe UTI with pyelonephritis
* Meningococcal disease
* Gut perforation Chlolecystitis /Cholangitis / Pancreatitis
* Infection of IV catheters and devices
* Skin and soft tissue infection
* Infection -cardiovascular e.g. endocarditis, Pneumonia
74
SSC Antimicrobial Recommendations
SSC Antimicrobial Recommendations
* Begin iv abx as early as possible and always within the first hour of recognising severe sepsis and septic shock
* Broad spectrum
* Consider combination empiric therapy in neutropenic patients
* Combination therapy no more than 3-5 days and de-escalation following susceptibilities
* Duration of therapy typically limited to 7-10 days, longer if response slow, undrainable foci or immunologic deficiencies
–Median time to antimicrobial administration: 6 hours
–Reduction in survival per hour not given: 7.6%
75
Typical antimicrobial therapies
Community acquired infection shock
according to origin of sepsis
unknown or gut. renal or binary
skin/soft tissue
pneumonia
meningococcal
malaria
**Origin unknown or gut, renal or binary**
Co-amoxiclav (‘Augmentin’) + gentamicin ADD VANCOMYCIN IF ?MRSA
Alternatives:
Cefuroxime + metronidazole + gentamicin
Ciprofloxacin + metronidazole + gentamicin
**Skin or Soft tissue**
Flucloxacillin + penicillin (or amoxicillin) +/- gentamicin
[consider adding clindamycin if Group A strep or Staph aureus toxic shock]
**Pneumonia**
Co-amoxiclav + doxycycline OR Cefuroxime + erythromycin
**Meningococcal disease**
Penicillin or Ceftriaxone
**Malaria**
Quinine
76
sepsis shock antibiotics for community acquired, if penicillin alergy
Penicillin or cephalosporin allergy?
If a rash only – consider using a penicillin or cephalosporin depending on allergy
If severe – Use agents such as ciprofloxacin, vancomycin , erythromycin (get advice)
77
TX for hospital acquired infection shock
## Footnote
Only been in a few days, no recent antibiotics → As for community acquired infection shock
Hosiptal acquired, longer stay
Typically use gentamicin + piperacillin-tazobactam (‘Tazocin’)
Check recent cultures and antibiotics received
_Prolonged admission, consider_
MRSA (Vancomycin)
ESBL positive GNR i.e. highly resistant GNR (Meropenem, Colistin)
VRE (Linezolid and others)
78
