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Infections in the Elderly

Infections in the Elderly. Jérôme Fennell, MB, MSc, PhD, FRCPath Jerome.Fennell@amnch.ie. Infections in Old Age. Risk Factors of Old Age Common Infections of Old Age RTI: Pneumonia, Influenza, TB Skin and Soft tissue infections Shingles Leg Ulcers GIT: C. Difficile UTI: ESBLs

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Infections in the Elderly

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  1. Infections in the Elderly Jérôme Fennell, MB, MSc, PhD, FRCPath Jerome.Fennell@amnch.ie

  2. Infections in Old Age • Risk Factors of Old Age • Common Infections of Old Age • RTI: Pneumonia, Influenza, TB • Skin and Soft tissue infections • Shingles • Leg Ulcers • GIT: C. Difficile • UTI: ESBLs • Renal function and aminoglycoside and glycopeptide dosing

  3. Risk factors for Infections in the Elderly Older, weaker, more at risk • More comorbidities • Gradual deterioration of immune system with age • May be malnourished, poor accommodation • More likely to harbour resistant organisms as more likely to have been • Hospitalised • in nursing home • Exposed to multiple antibiotics

  4. Cellular Immunity in the Elderly • Altered T cell phenotype •  naïve T cells;  memory T cells • Reduced T cell responses •  response to TCR stimulation •  T cell proliferation •  expression of IL2-R •  IL2 production Ginaldi et al 1999

  5. Case History: December 1999 • 67 yr old woman • PC: cough, left sided chest pain, rigors x 24h • HPC: productive cough most mornings, but increasingly purulent recently • PMHx: MI 2 yrs ago, smoked 40/day until then

  6. On Examination: • T: 40oC • Pulse: 130/min, BP: 145/90 • Tachypnoea • PMHx: MI 2 yrs ago smoked 40/day until then • Resp exam suggestive of consolidation

  7. Tests • FBC, WCC • Sputum for microscopy and culture • Blood culture • CXR • ABG • WCC – 22, 90% neutrophils • Sputum – pus cells, gram positive diplococci

  8. CXR Gram

  9. Sputum result Sputum – pus cells, gram positive diplococci…What does this tell us? More than you think – • No epithelial cells - suggests this is a good specimen from lower RT so should provide a good result on culture • Gram positive diplococci likely to be?

  10. Sputum Gram Stain • No longer done routinely • Not sensitive or specific enough • Not recommended in IDSA CAP guidelines • Guidelines now recommend another test instead...

  11. Urinary Antigen Testing • All severe pneumonias should have urine test for • Legionella Urinary Antigen • Pneumococcal Urinary Antigen • Should also think of CXR, pulse oximetry, ABG,

  12. Treatment Pneumococcus BenzylPen unless allergic or live in area of resistance (Irish rate of resistance-?) When cause unknown, use augmentin or cefotaxime to cover Haemophilus

  13. later… IV BenPen Transferred to ICU for ventilation because of hypoxia BCs – positive for S pneumoniae x2 WCC – 35 CXR – shows increasing consolidation and pleural effusion 24 hrs later – Cardiac arrest – RIP Next day S pneumoniae sensitivity available: R- Penicillin S – Erythromycin, Ceftriaxone

  14. RTI in Elderly • Strep. Pneumoniae • Influenza Virus • Recurrence of TB • Normal causes of RTI

  15. Pneumococcus • Common cause of community acquired pneumonia • Risk increased by smoking • Often occurs as secondary pneumonia after influenza infection • More common during winter months • Can also cause ENT, bacteremia and CNS infections • Latest EARSS Resistance Rates for Ireland: • Pen Non Susceptible 16.2% • Erythromycin Resistant 14.1% • Ceftriaxone/Cefotaxime Resistance Rare

  16. Pneumonia Symptoms • Fever (less common in those >75) • Cough with coloured sputum • Pleuritic chest pain, dyspnea • Altered mental function, particularly in the elderly • Increased or decreased WBC

  17. Strep pneumoniae • RTI: Amoxicillin/Clarithromycin if sensitive • If infection severe or previous antibiotic exposure, use IV Ceftriaxone or Cefotaxime • Augmentin has no added benefit because resistance is not due to B-lactamase production but do to different Pen binding proteins • In countries where Ceftriaxone resistance occurs in significant numbers use IV Ceftriaxone and IV Vancomycin empirically

  18. Pneumococcal Pneumonia • Elderly patients often have fewer or less severe symptoms than younger patients • Many community-acquired pneumonias are perfectly treatable as outpatients by oral antibiotics • >90 polysaccharide capsular types • HPSC Guidelines:

  19. Pneumococcal Vaccines 2 types of pneumococcal vaccine: • Polysaccharide Pneumococcal Vaccine (PPV23) • incorporates 23 of the most common capsular types which together account for up to 90% of serious pneumococcal infections • Only suitable for use in those ≥ 2 years of age • A conjugate 7 valent vaccine (PCV7) containing polysaccharide antigens from the 7 most common serotypes conjugated to a protein (CRM 197) has enhanced immunogenicity compared with the polysaccharide vaccine. • immunogenic even in infancy • active against approximately 70% of isolates causing invasive disease, and against a significant number of penicillin-resistant strains.

  20. HPSC Groups Requiring Vaccination At risk categories: • Asplenia or reduced splenic dysfunction (e.g. splenectomy, sickle cell disease and coeliac syndrome) • Chronic renal disease or nephrotic syndrome • Chronic heart, lung, or liver disease, including cirrhosis • Diabetes mellitus • Complement deficiency (particularly early component deficiencies C1, C2, C3, C4) • Immunosuppressive conditions (e.g. HIV, leukaemia, lymphoma, Hodgkin’s disease) and those receiving immunosuppressive therapies • CSF leaks either congenital or complicating skull fracture or neurosurgery • Intracranial shunt • Candidate for, or recipient of, a cochlear implant • Children under 5 years of age with a history of invasive pneumococcal disease, irrespective of vaccine history.

  21. Adults >65 • All should be offered single dose of Pneumococcal Polysaccharide Vaccine (PPV23) • Adults 65 years or older should receive a second dose of PPV23 if they received vaccine more than 5 years before and were less than 65 years of age at the time of the first dose.

  22. CURB-65 Score • Confusion – new onset • Urea - >7 mmol/l • Respiratory rate >30 breaths/minute • Blood Pressure <90/60 • Age>65 Score: 0-1 – Treat as outpatient 2 – consider admission or follow closely as outpatient > 3 requires hospitalization, mortality >17%

  23. Influenza • H1N1 flu pandemic declared over by WHO • now seen as part of seasonal flu • Current seasonal flu vaccine includes a H1N1 strain • Primary Influenza A infection can present abruptly as rapidly progressive diffuse pneumonia with pulmonary haemorrhage • More severe in elderly, may develop meningoencephalitis or encephalitis

  24. Influenza • Treatment: Neuraminidase inhibitors such as oseltamivir (PO) and Zanamivir (IV) given early in severe or at risk cases • Often followed by secondary bacterial pneumonia e.g. S pneumoniae, S aureus • Vaccine less effective in elderly • Adults over 50 should have annual vaccination • Those in nursing homes and other long stay facilities should also have annual vaccination

  25. Another Case • 82 year old woman with 2 months of cough, fatigue, night sweats • Poor response to Coamoxiclav, tetracycline

  26. TB in Ireland • Common in the 1950s • Many people who were exposed/treated as children then are now presenting with TB now as their immune system wanes with age

  27. Varicella Zoster Virus • Cause of Chicken Pox and later Shingles • Extremely infectious • Can be severe and even fatal in immunocompromised • Shingles not uncommon in elderly hospital patients, can leave severe pain of post-herpetic neuralgia • Pose an infection control risk to immunocompromised, and non immune staff especially to non immune pregnant staff

  28. Not routinely recommended in Elderly

  29. Leg Ulcers • As patients age, increasing peripheral vascular disease and diabetes can predispose to venous or arterial leg ulcers • Wet • Warm • Oxygenated • Below the belt • So swabs will always grow something, often grow patients bowel flora • Treat only if infected!

  30. Case History • Anne, 74 yr old housewife • PC: Elective total hip replacement – 3/7 ago • PMHx: Hypertension, Gastric Ca 13 yrs ago • 2/7 post op catheter specimen urine showed high white cells, Mixed growth predominantly gram negative bacilli • Given Zinacef po x 5/7

  31. Case History • 3/7 after Zinacef started, complains of diarrhoea Causes: • Infectious? – Any other patients on ward affected? • Non-infective causes? • Hospital food? • Secondary to drugs: • Antibiotic assoc diarrhoea? • Clostridium difficile?

  32. Case History Investigations? Stool Culture sent: • Culture – NAD, no Salmonella, Shigella, Campylobacter, or E coli 0157 • C diff toxin studies negative

  33. Case History What next? • Repeat C diff testing: Positive • Treatment?

  34. Case History • Treatment – po metronidazole 250 mgs qds for 10/7 • Diarrhoea settles – D/C home • Seen in OPD:

  35. What is C. difficile? Gram positive bacillus Clostridia = anaerobe Forms spores Spread by touch, faecal-oral route Main sources are: • asymptomatic carriers • Contaminated environment

  36. sensitive resistant Resistance to Antibiotics No antibiotic – no selection for resistant organisms

  37. sensitive resistant Resistance to Antibiotics antibiotic – selects for resistant organisms

  38. Clinical Picture • Clinical ranges from mild diarrhoea to life-threatening colitis • Occurs 1/7 to 6/52 after antibiotic exposure • Get watery diarrhoea, lower abdominal pain, blood pr

  39. Clinical Picture • Systemic symptoms: fever, anorexia, nausea and malaise • Severely ill may have no diarrhoea due to toxic megacolon • Complications: perforation, peritonitis – high mortality

  40. Risk Factors • Age • Prior antibiotic use • Length of hospital stay • Other severe underlying disease • C diff strain

  41. Antibiotic culprits • Any – including metronidazole • Main culprits include: • Clindamycin • Cephalosporins • Quinolones e.g. Moxifloxacin, Ciprofloxacin • Broad spectrum antibiotics – e.g. Augmentin, Meropenem

  42. Pathogenesis • Disrupts normal bowel flora • Many people especially neonates are colonised but not infected. • Carriers thought to have better immune response, infected tend to have lower Ab response • Two potent cytotoxins, toxins A and B • Can have colitis without pseudomembranes

  43. Spore Formation • Spores provide a method of survival when environmental conditions are unsuitable • Protect against ethanol, phenol, formaldehyde, heat • Killed by iodine, glutaraldehyde, hydrogen peroxide, autoclaving

  44. Stomach acid kills 99% bacteria but doesn’t affect spores

  45. Pseudomembranous Colitis • Due to Clostridium difficile toxins, rarely due to S. aureus • Symptoms: diarrhoea +/- mucus or blood, abdominal pain, tenderness, fever, dehydration, electrolyte disturbances • Dx by toxin detection or by endoscopy (risk of perforation) • Tx: Stop causative agent, give metronidazole or Vancomycin PO for 10/7

  46. Diagnosis • Culture too slow and those that grow may not express toxins • Therefore do toxin testing by ELISA • Pseudomembranes can be seen on endoscopy • Nursing nose! • No point in testing if clinically well or still on treatment

  47. O27 strain • Increasingly common • Associated with quinolone use • Higher mortality • Higher infectivity

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