Infections in geriatrics

1. Infections in GERIATRICS

2. INTRODUCTION
Infectious diseases have a significant morbidity and mortality in
the elderly population even in the modern area of antibiotics.
Waning immunity and the physiologic changes that come with
aging make the elderly especially prone to infectious diseases
such as pneumonia, urinary tract infection (UTI), and skin and
soft tissue infections.
 The clinical presentation of infection in the elderly is often
atypical, subtle, and elusive.
This makes early diagnosis and initiating treatment a challenge.

3. RISK FACTORS FOR INFECTIONS IN ELDERLY
Immune aging.
comorbid illnesses.
increased exposure to pathogens in institutions.
 complications of medical treatment.

4. ELDERLY ‘S EXPOSURE TO RESISTANT ORGANISMS
Elderly are more likely to harbour resistant organisms as more
likely to be – Hospitalized – Admitted to nursing home –
Exposed to multiple antibiotics.
Methicillin-resistant Staphylococcus aureus (MRSA).
vancomycin-resistant enterococci (VRE).
fluoroquinolone-resistant Streptococcus pneumonia.

5. COMPLICATION OF TREATMENT
Invasive devices, which include indwelling urinary catheters,
intravenous catheters, feeding tubes, and tracheostomies, are
more common in the elderly.
These devices compromise host defenses enabling bacteria to
enter the body and cause infection.
Chemotherapeutic, immunosuppressive therapy.

6. OUTCOMES FROM INFECTION IN ELDERLY
the mortality from common infections is 2 to 20 fold higher
than in younger adults.
Declines in the host inflammatory response, impaired functional
status, presence of comorbid illness, and virulence of the
infecting pathogen all contribute to the severity of the infection
and increased likelihood of death.
 In addition, delay in diagnosis and lack of treatment contribute
substantially to mortality from infection in older adults.

7. THE DELAY IN DIAGNOSING INFECTION IN ELDERLY
 The clinical findings of infection such as fever, changes in laboratory tests,
and physical findings may be atypical in older adults.
 the normal baseline temperatures are lower in elderly, The febrile response
may be absent or blunted in infected older adults.
 Other aspects of the inflammatory response, such as leukocytosis, may be
lacking in the older adult patient.
 Because of the lack of an inflammatory response, many older adults will
not have localizing symptoms or focal findings on physical examination.
 For example, typical signs of peritonitis may be unimpressive or absent in
the older adult with appendicitis, diverticulitis, or cholecystitis.

8. Treatment of PNEUMONIA
 Supportive treatment: 1. Chest percussion 2. Rehydration 3.
Bronchodilators 4. Oxygen therapy or mechanical ventilation.
 Initial regimens should be broadly inclusive, followed by step-down
therapy to narrower coverage if the causative agent is identified.
 For MRSA-colonized patients or patients in units with high rates of MRSA,
initial regimens should include vancomycin or linezolid until MRSA is
excluded.
 Patients with improving hospital-acquired pneumonia not caused by
nonfermenting gram-negative bacilli (eg, Pseudomonas,
Stenotrophomonas) can receive short courses of antibiotics (8 days).

9. Treatment of INFLUENZA
Treatment of the common cold is symptomatic with
acetaminophen, decongestants, and antihistamines.
However, many cold remedies contain medications that can
cause adverse effects in the elderly or interact with prescription
medications.
Antiviral treatment for influenza should be administered within
48h, and preferably within 12h, of symptom onset.

10. Treatment of INFLUENZA
The earlier the antivirals are administered, the more effective
they are in reducing symptoms and preventing complications.
The older antivirals amantadine and rimantidine are active only
against influenza type A.
The neuraminidase inhibitors zanamivir (inhaled) and
oseltamivir are effective against both influenza types A and B.
 Laninamivir: long acting inhaled neuraminidase inhibitors
approved in Japan but not in USA can be used for oseltamivir
resistant cases .

11. Treatment of TUBERCULOSIS
 latent disease : If the chest x-ray film does not reveal evidence of active
disease in a person with a positive skin test, it is recommended that
isoniazid (INH) therapy be administered for 6-9 months. Once-a-day
dosing with 300 mg of INH has been shown to decrease the incidence of
active TB by at least 60%. patients receiving treatment for latent disease,
monthly clinical monitoring for symptoms is essential.
 Active TB: Therapy for 6 months with two very effective anti-tuberculous
agents, isoniazid and rifampin, supplemented during the first 2 months
a third agent, pyrazinamide, is commonly used. In suspected resistant
organism a fourth drug (ethambutol) typically is added at the initiation of
therapy until drug sensitivity results become available.

12. Treatment of UTI
Single-agent empiric antimicrobial therapy is appropriate for all
patients with presumed UTI. course 7-10days.
Cystitis in elderly women has traditionally been treated with 7
days of antibiotics; a shorter duration may also be effective, but
more studies are needed.
Men with UTI usually have a prostatic focus and require 2- 6
weeks of treatment with an antibiotic such as trimethoprim-
sulfamethoxazole or a quinolone, both of which penetrate well
into the prostate.

13. Treatment of UTI
Patients with suspected sepsis from UTI require hospitalization
and treatment with a beta-lactam/beta-lactamase combination,
a third- generation cephalosporin, or a quinolone such as
ciprofloxacin plus aminoglycoside.
In catheterized patients, because of the possibility of infection
with gram-positive organisms (i.e., methicillin-resistant
Staphylococcus aureus and enterococci in up to 20% of
patients), it is also appropriate to consider using a beta-
lactam/beta-lactamase inhibitor combination or adding
vancomycin for empiric treatment.

14. Treatment of GASTROENTERITIS and
PSUEDOMEMBRANOuS COLITIS
 Treatment focuses on rehydration and electrolyte replacement.
 Patients with infectious inflammatory diarrhea, as evidenced by the
presence of fecal leukocytes, may be started on empiric antibiotics before
culture results.
 In other causes of community-acquired or traveler's diarrhea,
trimethoprim-sulfamethoxazole or a quinolone can be used.
Campylobacter may be resistant to quinolones and require erythromycin.
 C. difficile should be treated with oral metronidazole. Recurrent or severe
disease may require oral vancomycin, but this should not be used as first-
line therapy.
 Antimotility drugs should not be given for inflammatory diarrhea.

15. Treatment of INFECTED PRESSURE ULCERS
These infections are polymicrobial.
 the use of a beta-lactam/beta-lactamase inhibitor combination
should be strongly considered.
 Quinolone combined with metronidazole or clindamycin is
another option.
Because of poor tissue perfusion of infected pressure ulcers,
antimicrobial therapy should be administered intravenously in
all patients who are extremely ill.
Topical treatment is not effective for any infected pressure ulcer.

16. Treatment of INFECTIVE ENDOCARDITIS
Antimicrobial therapy must be bactericidal and prolonged.
Pts with acute endocarditis require antibiotic treatment as soon
as three sets of blood culture samples are obtained, but stable
pts with subacute disease should have antibiotics withheld until
a diagnosis is made.
Streptococci: Penicillin G (2–3 mU IV q4h for 4 weeks)
Ceftriaxone (2 g/d IV as a single dose for 4 weeks) or
Vancomycin (15 mg/kg IV q12h for 4 weeks) Penicillin G (2–3
mU IV q4h) or ceftriaxone (2 g IV qd) for 2 weeks plus
gentamicin (3 mg/kg qd IV or IM as a single dose or divided
into equal doses q8h for 2 weeks).

17. Treatment of INFECTIVE ENDOCARDITIS
 Enterococci: Penicillin G (4–5 mU IV q4h) plus gentamicin (1 mg/kg IV
q8h), both for 4–6 weeks. Can use streptomycin (7.5 mg/kg q12h) plus
gentamicin if there is not high-level resistance to streptomycin. Ampicillin
(2 g IV q4h) plus gentamicin (1 mg/kg IV q8h), both for 4–6 weeks.
Vancomycin (15 mg/kg IV q12h) plus gentamicin (1mg/kg IV q8h), both
4–6 weeks.
 Staphylococci Methicillin-susceptible: Nafcillin or oxacillin (2 g IV q4h for
for 4–6 weeks) plus (optional) gentamicin (1 mg/kg IM or IV q8h for 3–5
days).
 Staphylococci Methicillin-resistant: infecting prosthetic valves Vancomycin
(15 mg/kg IV q12h for 6–8 weeks) plus gentamicin (1 mg/kg IM or IV q8h
for 2 weeks) plus rifampin (300 mg PO q8h for 6–8 weeks).

18. Treatment of HIV IN ELDERLY
 A combination regimen, usually including a minimum of 3
different ARV agents, preferably from at least two different
classes.
 Nucleoside reverse transcriptase inhibitors (NRTIs),
nonnucleoside reverse transcriptase inhibitors (NNRTIs),
protease inhibitors (PIs).
 current treatment guidelines have established preferred
recommended regimens that include 1 NNRTI + 2 NRTIs or 1 PI
+ 2 NRTIs.