This document discusses infections in elderly patients. It notes that the elderly are more susceptible to infections like pneumonia, UTIs, and skin infections due to immunosenescence and physiological changes of aging. The clinical presentation of infections can also be atypical in the elderly, making diagnosis and treatment more challenging. Some key risk factors for infections in the elderly include chronic illnesses, exposure to pathogens in institutions, and medical treatments that involve devices. Pneumonia is provided as a detailed example, discussing causes, symptoms, investigations, and management considerations in elderly patients.

1. INFECTIONS IN
ELDERLY
DR. DOHA RASHEEDY
LECTURER OF GERIATRIC MEDICINE
DEPARTMENT OF GERIATRIC AND GERONTOLOGY
AIN SHAMS UNIVERSITY

2. INTRODUCTION
• Infectious diseases have a significant morbidity and mortality in the elderly
population even in the modern era 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.
• Older adults are more likely to be hospitalized as a result of infectious
processes and the longer the hospital stay, the greater the likelihood that
they will develop infectious complications.
• The clinical presentation of infection in the elderly is often atypical, subtle,
and elusive.
• This makes early diagnosis and initiating treatment a challenge.
• Elderly may not only have fewer symptoms, but might present with
nonspecific consequences of infection that on the surface appear
unrelated.
• Aside from prevention, early diagnosis with rapid institution of antimicrobial
therapy is the mainstay of treatment for reducing the high morbidity and
mortality of infection in the aged.

3. EXAMPLES ON NONSPECIFIC
SYMPTOMS:
• Generalized malaise
• Falls
• Changes in mental status or cognitive impairment
• Anorexia

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

6. AGEING IMMUNITY
Immunosenescence increases vulnerability of the elderly to
infection.
Alterations in the barriers posed by the skin, lungs, and gastrointestinal tract
(and other mucosal linings), permitting invasion by pathogenic organisms
SKIN:
• Epidermal Thinning:(ageing+ chronic disease and malnutrition)
• decreases in Langerhans cells, interleukin-1 production, and production and
response to epidermal thymocyte-activating factor.
• poor perfusion,
→ increase the risk of damage to the skin and the subsequent development of soft
tissue infection such as cellulitis and infected decubitus ulcers.
Mucosal surfaces :
also adversely affected by age, disease, and lifestyle (e.g., cigarette smoking) with loss
of the ciliary action of the epithelial cells of the upper respiratory tract and possibly
reduction of secretory immunoglobulins).

7. PRIMARY IMMUNITY
Consists of phagocytosis, complement, and natural killer cells.
Age in itself may have little effect on this form of immunity.
However, acute and chronic diseases, especially malnutrition,
may compromise these defense mechanisms.

8. ACQUIRED IMMUNITY
With advancing age,
• the percentage of memory cells increases in relation to naive cells as
the naive cells undergo a transition to memory cells.
• loss of the proliferative capacity of immune cells, and decreased
production of specific cytokines (eg, IL-2) that leads to increased risk
for intracellular pathogens.
• Impaired signal transduction after cytokine binding is also associated
with impaired defense against fungal and viral pathogens.
• lack of regulatory control of T cells on B cells in the elderly leads to a
blunted antibody response.
• Decreased antibody response to vaccines, related to reductions in
toll-like receptors. and senescence of CD8+ T cells .

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

10. 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.

11. 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.

12. 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.
• the older adult with altered cognitive function may not be able to
perceive symptoms of infection or communicate them to their health
care provider.

13. USEFUL INDICATORS
OF INFECTION
Functional status: is a sensitive indicator of infection in nursing home
residents.
Acute infection in the elderly often is heralded by a decline in mental or
physical function. Difficulty ambulating, frequent falls, incontinence, and
delirium
Fever: other definitions for fever have been recommended as a more
sensitive means of detecting infection in older adults.
Dehydration: Dehydration may accompany fever and suggest possible
infection in this population.
Complete blood count: White blood cell (WBC) count more than 14,000
cells/mm3
• Neutrophils more than 90%

14. FEVER
• Fever, the cardinal feature of infection, is absent in 30 to 50 percent of
frail, older adults, even in the setting of serious infections like pneumonia
or endocarditis.
• The blunted febrile response in older adults is due to changes in
multiple systems responsible for thermoregulation: shivering,
hypothalamic regulation and thermogenesis by brown adipose
tissue are all impaired with advanced age.
Fever definition — Relatively healthy, community-dwelling older
adults may be appropriately managed using conventional
definitions of fever. Fevers >38°C .indicate a potential for serious
infection, while hypothermia relative to baseline body
temperatures may signify severe infection or even sepsis .
Fever in frail elderly patients may be considered as one or more of
the following:
• Single oral temperature >37.8°C (>100ºF)
• Persistent tympanic membrane temperature ≥37.2°C (99.0ºF)
• Rectal temperature ≥37.5°C (99.5ºF)
• Rise in temperature of ≥1.1°C (≥2°F) above baseline
temperature.

15. PNEUMONIA

16. There are three types of pneumonia in the elderly:
community-acquired, nursing home-acquired, and nosocomial
pneumonia.
Recent developments in nomenclature include the term healthcare
associated pneumonia (HCAP), which was incorporated in the
2005 American Thoracic Society guidelines. HCAP refers to any
patient who develops pneumonia in the hospital, resides in a
nursing home or residential care facility, receives home wound
care, undergoes chronic dialysis, or is exposed to a family
member with a multidrug resistant pathogen

17. RISK FACTORS:
1. Chronic obstructive pulmonary disease and smoking are the most
pervasive risk factors for CAP. Smoking cessation for 5 years may
reduce excess risk of CAP by almost half.
2. Congestive heart failure
3. diabetes
4. lung cancer
5. immunosuppression
6. Previous pneumonia
7. other malignancies

19. SYMPTOMS AND SIGNS OF CAP
• Classical:
• Cough with or without sputum production, dyspnea, pleurisy chest pain,
fever, and chills are blunted or nonexistent in elderly patients who have
pneumonia.
• Elderly patients are almost twice as likely to have tachypnea as
younger patients.
• Delirium, dizziness, falls
• Sepsis up to septic shock or ARDS

20. Signs of bacterial pneumonia may include the following:
Hyperthermia (fever, typically >38°C)or hypothermia (< 35°C)
Tachypnea (>18 respirations/min)
Use of accessory respiratory muscles
Tachycardia (>100 bpm) or bradycardia (< 60 bpm)
Central cyanosis
Altered mental status

21. Local Physical findings may include the following:
Adventitious breath sounds, such as rales/crackles, rhonchi, or
wheezes
Decreased intensity of breath sounds
Egophony
Whispering pectoriloquy
Dullness to percussion
Tracheal deviation
Lymphadenopathy
Pleural friction rub

22. ORGANISMS
CAP:
Streptococcus pneumoniae, Haemophilus influenzae Staphylococcus
aureus, Moraxella catarrhalis, Pseudomonas aeruginosa, Escherichia
coli, Klebsiella pneumoniae ,
Atypical: Legionella pneumophilia, Chlamydia pneumoniae, Coxiella
burnetti, Mycoplasma pneumoniae
Viruses: Influenza A, Parainfluenza .
HAP: resistant organisms such as
Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumoniae ,
MRSA,
NHAP:
Streptococcus pneumoniae, haemophilus influenzae,Moraxella
catarrhalis

23. SEVERITY OF PNEUMONIA.
There are a variety of assessment tools that can assist in determining
the severity of pneumonia.
CURB-65
The modified American Thoracic Society (ATS) guidelines.
Pneumonia severity index scoring system

25. PSI
Class I (age 50,no coexisting illness, and no adverse clinical findings)
And II (PSI 70) are considered for outpatient treatment,
and class III (70-90) may be managed either as an inpatient or
outpatient
Class IV (PSI 91–130) and V (PSI score >130) for inpatient
management,
the index heavily weights age, assigning men over the age of 70 and
women over 80 into risk class III even if there are no other risk factors.
It neglects other areas such as social circumstances which are
important in deciding whether or not to admit elderly patients.

27. The authors suggest that the CURB-65 score can stratify patients
into 3 different management options:
group 1 (score 0 or 1) was found to have a low mortality of 1.5%
and can be considered for outpatient management
group 2 (score of 2, mortality intermediate 9.2%, can be considered
for hospital supervised treatment;
group 3 (score 3 or more, mortality high at 22%,) should be
considered for intensive care management if appropriate.

30. CRITERIA: HOSPITALIZATION INDICATIONS IN
NURSING HOME RESIDENTS
Assumes that patient is willing to be hospitalized
Indications for hospitalization (2 or more)
1. Respiratory Rate >30 bpm or 10 bpm over baseline
2. Oxygen Saturation <90% on room air
3. Systolic BP <90 mmhg or 20 mm Hg below baseline
4. Oxygen requirement >3 LPM over baseline
5. Uncontrolled comorbidity
• Uncontrolled Chronic Obstructive Pulmonary Disease
• Uncontrolled Congestive Heart Failure
• Uncontrolled Diabetes Mellitus
6. Altered Level of Consciousness
• New Somnolence
• New or increased agitation
7. Facility unable to care for patient
• Vital Signs every 4 hours
• Lab access
• Parenteral hydration
• Licensed nursing available

31. INVESTIGATIONS
• Leucocytosis and increase in band forms develop less frequently in
elderly patients and are thus less sensitive in the detection of
pneumonia.
• a normal CRP value virtually excludes pneumonia, even in the very
old.
• Blood gas analysis
• Microbiology: the question of whether sputum analysis should be
done is controversial (recommended by the Infectious Diseases
Society of America, but not by the American Thoracic Society).
Indeed, the elderly are often too weak to provide an adequate
sputum specimen, or too confused to cooperate and the diagnostic
yield of sputum analysis is relatively low.
• Blood cultures twice
• TEST for urinary legionella antigen ,PCR testing for Chlamydia spp,
M pneumoniae, and common respiratory viruses are now available,
but their clinical usefulness has not yet been established.
• BUN, electrolytes, glucose prognostic value

32. MANAGEMENT:
Supportive ttt:
1. Chest percussion
2. Rehydration
3. Bronchodilators
4. Oxygen therapy or mechanical ventilation

35. INSTITUTIONALLY ACQUIRED
PNEUMONIA
• 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).

37. DURATION OF ANTIBIOTIC THERAPY
Patients with CAP should be treated for:
1. a minimum of 5 days (level I evidence),
2. should be afebrile for 48–72 h.
Most patients with CAP have been treated for 7–10 days
longer duration of therapy may be needed if initial therapy was not
active against the identified pathogen or if it was complicated by
extrapulmonary infection, such as meningitis or endocarditis.

38. REDUCING THE RISK OF PNEUMONIA
• Immunization
• Smoking cessation
• Aggressive treatment of comorbidities (eg,
minimizing aspiration risk in post-stroke patients,
limited use of sedative hypnotics)
• System changes with attention to infection control
may be particularly effective in the nursing home

39. PATHOGENESIS OF HCAP
Colonization of the pharynx with bacteria is the most important step in the
pathogenesis of hospital-acquired pneumonia.
Pharyngeal colonization is promoted by:
• exogenous factors (instrumentation of the upper airway with nasogastric
and endotracheal tubes, contamination by dirty hands and equipment)
• treatment with broad-spectrum antibiotics that promote the emergence of
drug-resistant organisms)
• patient factors (malnutrition, advanced age, altered consciousness,
swallowing disorders, and underlying pulmonary and systemic diseases).
• Aspiration of infected pharyngeal or gastric secretions delivers bacteria
directly to the lower airway.
+ Impaired cellular and mechanical defense mechanisms in the lungs of
hospitalized patients raise the risk of infection after aspiration has
occurred.
Observational studies have suggested that elevations of gastric pH due to
antacids, H2-receptor antagonists, or enteral feeding is associated with
gastric microbial overgrowth, tracheobronchial colonization, and hospital-
acquired pneumonia. Sucralfate, a cytoprotective agent that does not alter
gastric pH, is associated with a trend toward a lower incidence of
ventilator-associated pneumonia.

40. The most common organisms responsible for hospital-acquired
pneumonia are P aeruginosa, S aureus, Enterobacter, K pneumoniae,
and Escherichia coli. Proteus, Serratia marcescens, H influenzae,
and streptococci account for most of the remaining cases. Infection
by P aeruginosa and Acinetobacter tend to cause pneumonia in the
most debilitated patients, those with previous antibiotic therapy, and
those requiring mechanical ventilation.
Anaerobic organisms (bacteroides, anaerobic streptococci,
fusobacterium) may also cause pneumonia in the hospitalized
patient; when isolated, they are commonly part of a polymicrobial
flora.
Mycobacteria, fungi, chlamydiae, viruses, rickettsiae, and protozoal
organisms are uncommon causes of hospital-acquired pneumonia.

42. CLINICAL FINDINGS
SYMPTOMS AND SIGNS
The symptoms and signs associated with hospital-acquired pneumonia are
nonspecific; however, one or more clinical findings (fever, leukocytosis,
purulent sputum, and a new or progressive pulmonary infiltrate on chest
radiograph) are present in most patients.
Other findings associated with hospital-acquired pneumonia include those
listed above for community-acquired pneumonia.
The differential diagnosis of new lower respiratory tract symptoms and signs in
hospitalized patients includes
1. congestive heart failure
2. Atelectasis
3. Aspiration
4. ARDS
5. pulmonary thromboembolism
6. pulmonary hemorrhage
7. drug reactions

43. Endotracheal aspiration using a sterile suction catheter and
fiberoptic bronchoscopy with bronchoalveolar lavage or a protected
specimen brush can be used to obtain lower respiratory tract
secretions for analysis, most commonly in patients with ventilator-
associated pneumonias.
Endotracheal aspiration cultures have significant negative predictive
value but limited positive predictive value in the diagnosis of specific
etiologic agents in patients with hospital-acquired pneumonia.
An invasive diagnostic approach using quantitative culture of
bronchoalveolar lavage samples or protected specimen brush
samples in patients suspected of having ventilator-associated
pneumonia leads to significantly less antibiotic use, earlier
attenuation of organ dysfunction, and fewer deaths at 14 days

45. INFLUENZA

46. VIRAL INFECTIONS OF
RESPIRATORY TRACT
Influenza types A and B, parainfluenza, coronavirus, and rhinovirus are
the cause of most common viral respiratory infections.
Influenza type A and respiratory syncytial virus (RSV) cause the
greatest morbidity and mortality.
Influenza types A and B cause epidemics of disease almost every
winter.
SYMPTOMS & SIGNS:
Classic influenza presents with abrupt onset of fever, chills, headache,
and myalgia, which are accompanied by pharyngitis, nonproductive
cough, and clear, watery nasal congestion. The fever accompanying
influenza infection can last from 4-8 days.
Common symptoms of RSV infection include rhinorrhea, cough,
sputum production, shortness of breath, and wheezing

47. LABORATORY TESTS
Viral culture for influenza using nasopharyngeal swab, is useful in
making an etiological diagnosis because the symptoms of influenza
may be similar to those of other viruses such as RSV.
Rapid antigenic tests, with 80-90% sensitivity and specificity
(depending on sample quality), are commercially available to detect
influenza types A and B.
Unfortunately, the sensitivity of culture for RSV is extremely poor
because the shedding of RSV in the oropharynx is low. In addition,
RSV is thermo-labile and does not survive long in transit.

48. PREVENTION
Hospitalization and mortality in both community-dwelling elderly and
nursing home residents are reduced when vaccine is administered
before the influenza season.
Side effects of the influenza vaccine are the same for the elderly as for
younger individuals: local soreness, low-grade fever, and muscle
aches.
When influenza occurs in a nursing home, the CDC recommends
antiviral prophylaxis for all residents to prevent an epidemic.
Prophylaxis should be continued for at least 2 weeks or, if cases
continue to occur, until 1 week after the outbreak has ended.
Amantadine is not recommended for postexposure prophylaxis .

49. TREATMENT
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 12 h, of symptom onset.
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
.

50. If the fever persists for more than 4 days with productive
cough and white cell count over 10,000/mcL,
secondary bacterial infection should be suspected.
Pneumococcal pneumonia is the most common such
infection, and staphylococcal pneumonia is the most serious

51. The treatment of RSV infection in the elderly is
supportive, with hydration, oxygenation, and
treatment of bronchospasm with bronchodilators. It is
unclear whether aerosolized ribavirin affects
symptoms in the elderly
palivizumab, a monoclonal RSV antibody. Administration of
palivizumab prophylactically (parenterally at 15 mg/kg monthly
during the season of high transmission) to patient at risk
cardiopulmonary conditions.
No active vaccination available for RSV to date

52. TUBERCULOSIS

53. Most TB in the elderly is a result of reactivation of latent infection
and involves the lungs. However, extrapulmonary TB, including
miliary disease, is more frequent in the elderly than in younger
individuals.
Reactivation is thought to occur because of a decline of cell-
mediated immunity with age and the co-morbid medical conditions.
• Malignancy, diabetes, lymphoreticular cancers, poor nutrition, renal
insufficiency as well as chronic institutionalization increase the risk
of TB in the elderly

54. SCREENING FOR LATENT DISEASE
• The tuberculin test is the best available screening test to detect
previous infection.
• It is recommended that only those who have increased risk for TB be
screened:
1. residents and employees of nursing homes
2. persons with recent close contact with an active case
3. those who have immigrated within the past 5 years from a country with a
high prevalence of TB;
4. and those with certain medical conditions such as diabetes, renal disease,
significant weight loss, and immunosuppression.
• a 2-step TB test 2 weeks apart should be done if the initial test is
negative.
• 10 mm of induration as a positive test in most individuals; 5 mm of
induration is considered positive in those with HIV infection, persons
receiving immunosuppressive therapy, recent contacts of active
cases, and patients with a chest x-ray film consistent with prior TB.
• interferon- assays

55. TREATMENT
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
mo. 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 by 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

56. UTI

57. URINARY TRACT INFECTION
Urinary tract infection (UTI) is the most common illness in
adults age 65 and over.
The incidence rate approaches 10 percent in women and 5.3
percent in men over the age of 80.
Organisms:
Gram-negative bacilli (eg, E. coli, Enterobacter spp.,
Klebsiella spp., Proteus spp.) are most common
but there is an increase in more resistant isolates such as
Pseudomonas aeruginosa, and gram-positive organisms
including enterococci (E. fecalis and E. faecium),
coagulase-negative staphylococci and Streptococcus
agalactiae (group B strep), when compared to young adults.

58. RISK FACTORS FOR UTI IN ELDERLY
Increased risk for UTI in the elderly is associated with:
1. changes of aging, including prostatic hypertrophy and loss of
estrogen effect
2. neurogenic bladder from stroke or diabetes, incontinence
3. use of indwelling and condom catheters.
4. Nursing home admission.
5. Diabetes.

59. Asymptomatic bacteriuria
Asymptomatic bacteriuria (> 100,000 colonies/mL on 2 consecutive
specimens in an asymptomatic patient)
affect 1-6% of men and 10-20% of women over age 60 in the community
and 15-35% of men and 25-50% of women in nursing homes.
There is no clinical benefit when asymptomatic bacteriuria is
treated.
Distinguishing asymptomatic from symptomatic infection may be
difficult.
Reliance on clinical evidence of infection in making a decision to treat
is compromised by the frequent absence of fever in infected elderly
patients and by the inability of many patients to describe symptoms.
However, in the absence of some objective evidence of infection, such
as fever, flank pain, or change in cognitive or functional status, no
clinical benefit when treated.

60. TREATMENT
Single-agent empiric antimicrobial therapy is appropriate for all patients
with presumed UTI. course 7-10days
1. 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.
2. In nursing home patients, breadth of coverage should be based on the
antibiotic resistance pattern in the facility.
3. 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.
4. In catheterized patients, because of the possibility of infection with
gram-positive organisms (ie, 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.
Once culture results are available, the empiric antibiotic regimen should
be changed to an appropriate antibiotic with the narrowest spectrum.

61. GASTROENTERITIS

62. A decrease in gastric acidity as a result of medications, gastric atrophy,
surgery, and systemic illnesses increases the risk of infection with
gastrointestinal pathogens.
Elderly patients living in nursing homes or other group settings are at
particularly high risk because of shared bathrooms and dining facilities,
the high prevalence of incontinence, and poor staff compliance with hand-
washing practices.
Causative organisms:
In outpatients with diarrhea, viral pathogens are most common
The principal bacterial pathogens causing diarrhea in the elderly are C.
difficile, Campylobacter species, Escherichia coli, Salmonella species,
and Shigella species. When onset of symptoms is within 12 h of ingestion
of contaminated food, the toxins of Clostridium perfringens, Bacillus
cereus, or S. aureus may be responsible.
Antibiotic-associated diarrhea caused by C. difficile is common in the
elderly because of more hospitalizations, nursing home stays, and
antibiotic use. Up to 50% of patients older than 65 will develop C. difficile-
associated diarrhea after hospitalization and antibiotic use. Much of the
problem with C. difficile is due to poor infection control practices.

63. PSUEDOMEMBRANOS COLITIS
• Clinical ranges from mild diarrhoea to life-threatening colitis
• Occurs 1/7 to 6/52 after antibiotic exposure
• The patient experiencing diarrhea may have crampy lower
abdominal pain, anorexia, fever, malaise, and watery or bloody
diarrhea. In general, symptoms are not specific enough to
identify the causative pathogen
• C. difficile can cause severe diarrhea, fever and systemic toxicity
• Severely ill may have no diarrhoea due to toxic megacolon
• Complications: perforation, peritonitis – high mortality

64. LABORATORY TESTS
•Stool culture: indicated when there is a history of recent travel,
recent hospitalization, inflammatory bowel disease, prior
antibiotic use or unsafe food ingestion; when illness occurs in a
cluster; when fever, dehydration, abdominal pain, or bloody
diarrhea is present; when the patient is immunocompromised;
when symptoms are severe or prolonged; and when fecal
leukocytes or blood are present.
•Bacterial cultures for Salmonella, Shigella, E. coli, and Yersinia
should always be obtained in patients hospitalized because of
diarrhea and in nursing home patients with diarrhea.
•A stool examination for ova and parasites should be done when the patient is
immunocompromised, has traveled recently, or has prolonged diarrhea.
•testing for C. difficile toxin: Suspicion of C. difficile should be high in any hospital
or nursing home-acquired diarrhea, especially with history of antibiotic use.
•Flexible sigmoidoscopy or colonoscopy looking for pseudomembranes should be
performed for persistent diarrhea with negative stool studies.

65. TREATMENT
• 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.

66. INFECTED
PRESSURE
ULCERS

67. Clinical evidence of infection includes warmth, tenderness, purulent
discharge, foul odor and tissue crepitus.
Superficial swab cultures collect surface-contaminating organisms,
and a positive swab culture does not necessarily mean that the ulcer
is infected.
Tissue biopsy and culture and fluid irrigation/aspiration cultures are
superior alternatives. However, tissue irrigation and aspiration may
yield positive results even in non infected ulcers.
The most common aerobic isolates obtained from cultures are
Proteus mirabilis, enterococci, E. coli, staphylococci, and
Pseudomonas.
The most common anaerobic isolates are peptostreptococci,
Bacteroides, and Clostridia.
Bacteremia from infected pressure ulcers is more frequently from
anaerobes than aerobes and is associated with a high mortality.

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

69. INFECTIVE
ENDOCARDITIS

70. Originally known as bacterial endocarditis, it can also be caused by
fungi, rickettsia, and chlamydia.
IE has become more frequent in older patients, with a majority of
patients older than 50 years.
IE can be divided into three major groups based on host
characteristics:
1. Native valve endocarditis (NVE)
2. Prosthetic valve endocarditis (PVE); further subdivided into early
(i.e., in the first month after valve surgery) and late (occurring
thereafter)
3. Endocarditis in IV drug users

71. ORGANISMS
Most cases of NVE are caused by Streptococcus viridans (50%)
and Staphylococcus aureus,
whereas most cases of IE in IV drug users are caused by S.
aureus.
Early PVE is thought to be caused by intraoperative
contamination with nosocomial pathogens, in particular
coagulase-negative Staphylococcus.
Late PVE is believed to be community acquired and resembles
NVE in microbiology.

72. DIAGNOSIS
The major Duke criteria are:
1. Persistently positive blood cultures with microorganisms consistent
with IE
1. more than two positive cultures separated by at least 12 hours or more
than three cultures at least 1 hour apart or 70% of blood cultures
positive if four or more are drawn
2. A single positive blood culture for Coxiella burnetii or IgG antibody titer
>1:800
2. Echocardiographic evidence of endocardial involvement
The minor Duke criteria are:
1. Predisposing heart condition
2. Fever
3. Vascular phenomena (arterial emboli, septic pulmonary emboli,
mycotic aneurysm, Janeway lesions)
4. Immunologic phenomena (glomerulonephritis, Osler nodes, Roth
spots, rheumatoid factor)
5. Positive blood cultures (not meeting major criteria)
Definitive diagnosis of IE requires two major criteria or one major plus
three minor criteria or five minor criteria.

74. TREATMENT
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)
Vancomycinc (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
gentamicind (3 mg/kg qd IV or IM as a single doseeor divided into equal
doses q8h for 2 weeks

75. Enterococcih
Penicillin G (4–5 mU IV q4h) plus gentamicind (1 mg/kg IV q8h), both for
4–6 weeks Can use streptomycin (7.5 mg/kg q12h) in lieu of gentamicin
if there is not high-level resistance to streptomycin
Ampicillin (2 g IV q4h) plus gentamicind (1 mg/kg IV q8h), both for 4–6
weeks
Vancomycinc (15 mg/kg IV q12h) plus gentamicind (1mg/kg IV q8h), both
for 4–6 weeks
Staphylococci
Methicillin-susceptible,
Nafcillin or oxacillin (2 g IV q4h for 4–6 weeks) plus (optional)
gentamicind (1 mg/kg IM or IV q8h for 3–5 days)
Can use penicillin (4 mU q4h) if isolate is penicillin-susceptible
Cefazolin (2 g IV q8h for 4–6 weeks) plus (optional) gentamicind (1
mg/kg IM or IV q8h for 3–5 days)
Vancomycinc (15 mg/kg IV q12h for 4–6 weeks)

76. 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)

79. HIV IN
ELDERLY

80. INTRODUCTION
AIDS is increasing in elderly population:
1. the success of combination antiretroviral therapy added to life
expectancy of the patients.
2. the risk of new HIV infections is also likely to increase:
1. the use of sildenafil to effectively treat erectile dysfunction and
enhance sexual performance may increase risky sexual behavior.
2. Additionally, postmenopausal women may be less likely to request
that condoms be used as they face no risk of pregnancy.
3. Finally, age-associated declines in immunity may place older
individuals at higher risk of transmission with each exposure

81. CLINICAL PRESENTATION
Like in younger patients, acute infection
may be completely asymptomatic or
present as a flu-like syndrome.
older who are chronically infected with
HIV and in care, the most common self-
reported symptoms are fatigue, peripheral
neuropathy, problems sleeping, myalgias
or arthralgias.

82. Physical exam
Skin: Kaposi’s sarcoma, psoriasis, seborrheic dermatitis and varicella
zoster scars
Oral pharynx: Periodontal disease, thrush, Kaposi’s sarcoma
Optic fundi: HIV cotton wool spots, CMV retinitis
Lymphatic: Lymphadenopathy, splenomegaly
Genital and rectal exam: Herpes simplex (HSV) ulcers or scars,
fissures, fistulas, condyloma accuminatum, condyloma latum
Neurologic exam: Altered mini-mental status, distal sensory
neuropathy

83. CLINICAL CONDITIONS THAT MAKE PHYSICIAN SUSPECT
UNDIAGNOSED-HIV INFECTION
Unexplained lymphadenopathy
constitutional syndromes‘‘AIDS-related
complex’’ (ARC)
• Fever of unknown etiology
• Chronic fatigue
• Unexplained weight loss
• Unexplained chronic diarrhea
Neurologic syndromes
• Acute aseptic meningitis
• Fungal meningitis
• Unexplained dementia
Skin findings
• Recurrent Staphylococcal furunculosis
• Severe seborrheic dermatitis
• Unexplained exacerbation of psoriasis
• Shingles
• Kaposi’s sarcoma
Oral findings
• Thrush
• Hairy leukoplakia
• Aggressive periodontitis
• Severe recurrent aphthous ulceration
• Kaposi’s sarcoma
Pneumonias
• Recurrent pneumococcal pneumonia
• Pneumocystis carinii pneumonia
• Tuberculosis
• Fungal pneumonia (eg histoplasmosis,
coccidioidomycosis)
Hepatitis
• Hepatitis B
• Hepatitis C
Sexually transmitted diseases
• Herpes simplex
• Gonorrhea
• Chlamydia
• Human papilloma virus
• Genital warts
• Syphillis
Hematologic findings
• Thrombocytopenia
• Neutropenia
• Anemia
• Lymphopenia (absolute count <1000 roughly
corresponds with CD4 <200)

84. DIAGNOSIS
Antibody tests are the standard tests for detecting HIV infection in most
patients. These tests are highly sensitive but can miss HIV infection in
some circumstances, such as when the infection is caused by HIV-2, a
virus common in West Africa, or when the test is performed early in HIV
infection before antibody has had a chance to develop.
Confirmation:
followed by a confirmatory test such as a Western blot or
immunofluorescence assay (IFA) if the screening test is
positive.
screening:
Testing of saliva or urine for HIV antibody is usually done in
community testing programs, Rapid HIV tests are not
approved for use in screening organ or blood donors

86. INITIATION OF THERAPY
Untreated asymptomatic adults should be examined every 6 months,
and the CD4 count and HIV viral load should be performed and
evaluated every 3 months.
Guidelines have been established as to when ARV treatment should be initiated
based on the CD4 count. In general, ARV treatment should be recommended to
anyone with an AIDS-defining illness, HIV-associated nephropathy, or a CD4 count
<200cells/mm3 regardless of viral load level

87. HIV TREATMENT
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.
.

89. ADVERSE EFFECTS AND DRUG INTERACTIONS
WITH HIV MEDICATIONS
Commonly at start of therapy: nausea, vomiting, abdominal discomfort,
malaise, and headache.
Alterations in lipid metabolism, body fat redistribution, diabetes, lactic
acidosis, and bone disorders are being increasingly recognized—especially
in patients on long-term therapy

92. THANK YOU