infections in geriatrics, 2006

Infections in Geriatrics, 2013

Jerome M. Larkin, M.D.

Slides courtesy of:Staci A. Fischer, M.D., FACP

Division of Infectious Diseases

The Warren Alpert Medical School of Brown University

Outline • Epidemiology of infections in the elderly

• Immune senescence

• Fever of unknown origin

• Pneumonia

• UTI

• Skin and soft tissue infection

• Bloodstream infection, endocarditis

• C. difficile in the elderly

• Antibiotics in the elderly

• Infection prevention

Who is old?

• Young Old: 65-75

• Middle Old: 75-85

• Old Old: >85

• 15% of new HIV infections in those >50 years

Clinical Practice Guideline for the Evaluation of Fever and Infection in Older Adult Residents of Long-Term

Care Facilities

High KP, Bradley SF, Gravenstein S, et al, CID 2009:48, 149

IDSociety.org

Infections in the Elderly: Trends

• By 2030, 20% of the US population will be over the age of 65 (69 million)

• 1990-2002 (Arch Intern Med 2005;165:2514-20)

– 21.4 million hospitalizations; DRG data

– 48% had an infection as primary Dx

– Infection related hospitalizations increased 13% over that time period

– Highest rates of hospitalization for infection were in those > 85 years

Infections in the Elderly: Trends

• 22% increase in rate of hospitalization for septicemia

• Rates for LRTI, UTI, intraabdominal infections were stable

• Increases: endocarditis (240%), prosthetic device-related infxn (130%), postoperative infections (80%)

• 1/3 of deaths >65yrs attributed to infxn

Infections in the Elderly: Trends

• 46% of infection hospitalizations were for lower respiratory tract infections – 48% of infection-related hospital deaths

• 16% urinary tract infections – 70% women

– 6% of infection-related hospital deaths

• 12% septicemia – 34% of infection-related hospital deaths

Immunosenescence in the elderly

• NK cell function impaired; increased #s

• PMN migration is random, delayed

• Phagocytosis intact (DM, chronic bronchitis are exceptions)

• Increased sensitivity to cytokines that induce apoptosis

• Decreased peroxide and nitric oxide production, IL-2, CD8, TLR’s, Ig production/naïve B-cells

• Impaired wound healing

• Impaired response to vaccinination

Clin Infect Dis 2000;31:578-85.

Aging and infection

• 3-fold increase in prevalence of CAP

• 20-fold increase in prevalence of UTI

• Increased risk of infection per day of hospitalization

• Greater diversity of pathogens than in younger adults – Listeria

– Tuberculosis

– Legionella

– Pneumococcus

Lancet Infect Dis 2002;2:659-66

Aging and infection

• Altered barriers to infection: GI, Resp tracts, skin

• Increase in communal living/daycare leads to exposure to circulating pathogens, resistant organisms

• Immune fxn impaired by increased number of co-morbidities

• Chronic conditions exacerbated by infections

Aging and infection: Challenges

• Clinical presentation differs markedly

– Fewer symptoms

– Fever absent or blunted in 20-30% severe infections

– Nonspecific symptoms (delirium, anorexia, weakness, etc.)

• Yield of diagnostic tests may be lower

• Cognitive impairment decreases ability to relate symptoms, compliance with tx

Lancet Infect Dis 2002;2:659-66

Signs of Potential Infection

• Fever

• New or increasing confusion

• Incontinence

• Falling

• Deteriorating mobility

• Decreased appetite/fluid intake

• Failure to cooperate with staff

Fever in the Elderly

• 1/3 of patients with acute infection have no fever

• Lower baseline temperatures (36.7°C vs. 37.3°C)

• Onset of fever delayed several hours

• Best method of measurement: rectal>TM>oral

• Any acute change in functional status should raise suspicion of infection

Definition of fever in the elderly*:

• Increase in baseline temperature by > 1.1°C (2oF) or

• Single measurement over 37.8°C (100°F) or

• Two measurements over 37.2 °C (99°F)

*Healthy elders in the community can probably be

approached more conventionally

Fever of Unknown Origin in the Elderly

• Elderly: etiology determined in 87-95%

• 35% infection – 10% tuberculosis, 12% intraabdominal abscess,

7% endocarditis*, 6% other

• 30% connective tissue diseases temporal arteritis polymyalgia rheumatica rheumatoid arthritis

• 20% malignancy (lymphoma, hepatic mets)

• 8% DVT, drug fever, hyperthyroidism

*increased PV, AS valve dz, devices, interventions, S. aureus

Urinary Tract Infections in the Elderly

• Asymptomatic bacteriuria increases with age (1 in 10 men, 1 in 5 women) – Treatment rapid relapse

– Higher incidence of antibiotic toxicity in the elderly (more rapid absorption, drug interactions, etc.)

– Urinary tract abnormalities (cystocoele, rectocoele, urethral strictures, etc.)

– Chronic catheterization (100% with bacteriuria and WBC’s)

– If no symptoms and no pyuria . . . NO NEED TO TREAT

��UTI in the Elderly: DX

• Catheter: one of the following-

– Fever

– New onset CVA tenderness

– New onset delerium

– Rigors

UTI in the Elderly: DX

• No Catheter: Acute Dysuria or Fever and one of the following-

– New or worsening urgency

– Frequency

– Suprapubic pain

– Gross hematuria

– CVA tenderness

– Incontinence

UTI in the elderly

• Ambulatory patients: E. coli

• Nursing Home residents: Enterococcus, Klebsiella, Proteus, Pseudomonas

• Indwelling catheters: Providencia – > 10 wbc’s is significant

– If MRSA, VRE, Candida – remove or change the catheter (biofilms)

• Staph aureus: think endocarditis

UTIs in the elderly: Treatment

• Culture is critical in this population

• 3-5 days in women without catheters(?)

• 14 days in men or catheterized women

• Candida: Change the catheter!!!

• Relapses are common – repeat U/A, culture one week after antibiotics discontinued

• Remember that pyuria is the key to Dx

Pneumonia in the elderly

• >900,000 cases of community-acquired pneumonia in adults > 65 yrs annually

• 1 in 20 people above the age of 85 has pneumonia each year

• Risk factors: COPD, CHF, DM, malnutrition, swallowing disorders, alcoholism

• Smoking increased risk of pneumococcus

• Highest risk for related bacteremia among infxns in the elderly

Clin Infect Dis 2004;39:1642-50

Pneumonia in the Elderly

• Frequency of bacterial pneumonia increases with age

• Atypical presentation delayed treatment increased mortality

• Cough, pleuritic chest pain, fever often absent

• Altered mental status is the most common symptom

Pneumonia in the elderly

• Silent microaspiration of oropharyngeal secretions – Sleep indium-111 gauze study (Kikuchi, 1994): 71%

with CAP aspirated, 10% age-matched controls

– Feeding tubes may actually increase the risk of pneumonia and death in those who aspirate

• Mortality: bedridden before pneumonia, hypothermia, creatinine > 1.3, swallowing disorder

• Recovery can be prolonged (months) – Hospitalization, immobility

Pneumonia in the elderly: DX

• Tachypnea (>25)

• Hypoxia

• New infiltrate

• Purulent sputum

Pneumonia in the Elderly

• Viral: influenza, RSV

• Bacterial: Pneumococcus GNRs (E. coli, Klebsiella) Haemophilus influenzae Staph aureus Legionella pneumophila

• Empiric treatment: broad spectrum vs guided by culture

• NHR: increasing resistance (ESBL’s)

Pneumonia in Elderly: Pathogens

• Viral: influenza, RSV, Human Metapneumovvirus

• Bacterial: Pneumonococcus, GNR’s (Klebsiella, Haemophilus), Moraxhella, S. aureus*

• Atypical: Legionella, Chlamydia

• TB *post influenza

Antibiotic resistance in LTCFs

• MRSA

• VRE

• ESBLs

• Candida resistance

• Antibiotic overuse, crowding, infection control, indwelling catheters, microaspiration, frequent hospitalizations

Tuberculosis

• Nursing home outbreaks

• Two-step PPD testing in all elderly

• Symptoms atypical

• Disseminated infection more common

• +PPD: isoniazid tolerate AST, ALT < 500 U/L

Skin and soft tissue infections

• Cellulitis: MRSA, group A Strep (outbreaks in nursing homes), slow to resolve

• Herpes zoster

• Pressure sores (polymicrobial) – Rule out underlying osteomyelitis

– Surface cultures unreliable

– Bone biopsy cultures are best

• Scabies/Lice:

– suspect if >1 unexplained rash

– often detected when staff develop symptoms

• Conjunctivitis:

– respiratory bacteria (culture helpful), adenovirus

• Candida

– can be resistant species if not responding to typical rx

Bloodstream Infections

• Urinary tract, respiratory tract, skin, intraabdominal infections, IV catheters associated with ~6% 2ndary bacteremia

• GNR’s more likely as pathogens due to GI/GU source

• May result in vertebral osteomyelitis, hematogenous spread to femur, tibia, humerus (present months later with pain)

Bloodstream Infections

• 5-40 episodes/100,000 patient days

• Associated with high mortality (11- 50%)

• Death often seen in first 72 hours

• Mortality highest with associated pneumonia

• Elderly at relatively high risk of having contaminants isolated from BCx’s due to difficulty of phlebotomy

Endocarditis in the Elderly

• Men > women; mitral > aortic

• Staphylococci

• Streptococci [Strep bovis (colon CA)]

• Enterococci

• Lethargy, malaise, fatigue, anorexia, weight loss

• Back pain, arthralgias, stroke syndrome

• Microscopic hematuria, proteinuria

• TTE: less specific in the elderly

Prosthetic Device Infections

• Prevalence of Prosthetic Joints, Pacemakers, Fixation Hardware, Vascular Grafts all increase with age

• Are permissive to infection due to formation of biofilms

• Typically infections due to Staphylococci, Streptococci

• Treatment typically requires removal with prolongs abx courses with bactereicidal agents

• Goal of treatment should be maintenance of functional status>>>curative vs suppressive treatment

C. Difficile colitis in the elderly

• Antibiotic use (bacitracin for VRE colonization, UTIs/bacteriuria)

• Outbreaks in LTCFs

• May not present with diarrhea, but with abdominal distension and mental status changes

• Toxic megacolon more common

• Mortality increasing in the elderly

• Spores not destroyed by etoh gels

Antibiotics in the elderly

• Altered absorption, distribution, metabolism interactions

• More toxicity – Levofloxacin: CNS toxicity, delerium

– Gatifloxacin, gemifloxacin: hypoglycemia

– Linezolid: hematologic toxicity, interaction with SSRIs (MAOI)

– Aminoglycosides: renal toxicity, vestibular toxicity

– INH, rifampin: hepatotoxicity

– Carbapenems: tremor, seizures

– Telithromycin: hepatotoxicity

Antibiotics in the elderly:

• 40% of those over 70 have GFR<60

• Achlorhydria, gastroparesis, H2 blockers, PPI’s, antacids may alter absorption

• Net interactions may be difficult to predict: rifampin, bactrim, warfarin, quinolones, beta-blockers, statins, dig

• Cost may decrease compliance

12 month observational study of abx use in Canadian nsg homes: 22 facilities, 2400 patients, 9300 courses of abx

• 8-17% on abx at any one time

• 50-70% treated in the past year

• 22-89% of treatment courses inappropriate

Loeb M, et al; J Gen Intern Med 2001; 16:376

Infection Prevention in the Elderly

• Vaccinations: influenza, pneumococcus (q5-6 years; 23-valent), Tdap x1 then Td q 10 yrs, zoster

• Avoid indwelling lines, catheters

• Nutritional support

– MVI, zinc, selenium

– Watch vitamin A: decreased CD3 and CD4 cells?

– Vitamin E?

– Protein: up to 1.2 g/kgday improves wound healing, muscle mass/mobility

Questions???