INFECTIONS IN ELDERLYDR. DOHA RASHEEDY

LECTURER OF GERIATRIC MEDICINE

DEPARTMENT OF GERIATRIC AND GERONTOLOGY

AIN SHAMS UNIVERSITY

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.

EXAMPLES ON NONSPECIFIC SYMPTOMS:

• Generalized malaise• Falls• Changes in mental status or cognitive impairment• Anorexia

RISK FACTORS FOR INFECTIONS IN ELDERLY• Immune aging.

• comorbid illnesses.

• impaired functional status.

• increased exposure to pathogens in institutions.

• complications of medical treatment.

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).

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.

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 .

•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

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.

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.

THE ATYPICAL PRESENTATION OF INFECTION IN THE ELDERLY

factors that contribute to the atypical presentation of infection in the elderly compared to the young:

• underreporting of illness

• coexisting diseases such as chronic bronchitis, which may mask acute pneumonia,

• Altered physiologic responses to infection,

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.

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%

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, vasoconstriction, 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 oral or 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.

PNEUMONIA

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 in-

corporated in the 2005 American Thoracic Society guide-

lines. 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 multi-

drug resistant pathogen

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

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 up to septic shock or ARDS

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

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

ORGANISMSCAP: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

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

PSIClass I (age 50,no coexisting illness, and no adverse clinical findings) And II (PSI 70) are considered for outpatient treatment,

Class IV (PSI 91–130) and V (PSI score >130) for inpatient

management,

and class III may be managed either as an inpatient or outpatient

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.

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; and group 3 (score 3 or more, mortality

high at 22%,) should be considered for intensive care

management if appropriate.

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 baselin

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

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

MANAGEMENT:

Supportive ttt:

Chest percussion

Rehydration

Bronchodilators

Oxygen therapy or mechanical ventilation

INSTITUTIONALLY ACQUIREDPNEUMONIA

• 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).

DURATION OF ANTIBIOTIC THERAPY

Patients with CAP should be treated for a minimum of 5 days (level I evidence), should be afebrile for 48–72 h, and should have no more than 1 CAP-associated sign of clinical instability (table 10) before discontinuation of therapy (level II evidence). (Moderate recommendation.)

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.

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

INFLUENZA

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 myalgias, 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

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.

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 prophylaxis has been shown to control influenza outbreaks in nursing homes. Fewer data are available on use of the newer agents in institutional outbreak control.

TREATMENTTreatment 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.

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.

TUBERCULOSIS

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 development of medical conditions.

• Malignancy, diabetes, lymphoreticular cancers, poor nutrition, renal insufficiency as well as chronic institutionalization increase the risk of TB in the elderly

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

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

UTI

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.

RISK FACTORS FOR UTI IN ELDERLY

Increased risk for UTI in the elderly is associated with changes of aging, including prostatic hypertrophy and loss of estrogen effect, neurogenic bladder from stroke or diabetes, incontinence, and use of indwelling and condom catheters.

Nursing home admission.

Diabetes.

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,

TREATMENTSingle-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.

In nursing home patients, breadth of coverage should be based on the antibiotic resistance pattern in the facility.

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 (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.

PROPHYLAXISAntibiotics Not recommended due to resistance:

1. Long-term prophylaxis can be given at bedtime using the following antimicrobials: trimethroprim/sulphamethoxazole (TMP-SMX), trimethroprim (TMP), nitrofurantoin or norfloxacin.

Long-term prophylaxis usually entails administration for 6–12 months, although in certain cases this has been extended to 2–5 years. This effectively prevents recurrences in 95% of patients whilst they are on prophylaxis. However, 50% of patients will have an infection within 3 months after prophylaxis has been discontinued.

In addition to these antibiotics, cephalexin 125 mg is used. All the previously

mentioned medications can be given on alternate nights or 3 nights a week.

2. Cranberry juice 250 ml/day give prophylaxis for 2 months

3. Topical estrogen to overcome vaginal urethral atrophy.

GASTROENTERITIS

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.

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

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.

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. Where Shiga toxin-producing E. coli is suspected (nonbloody diarrhea without fever), antibiotics are not recommended because they may increase the risk of hemolytic uremic syndrome.

• 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.

INFECTED PRESSURE ULCERS

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.

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.

INFECTIVE ENDOCARDITIS

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:

•Native valve endocarditis (NVE)

•Prosthetic valve endocarditis (PVE); further subdivided into early (i.e., in the first month after valve surgery) and late (occurring thereafter)

•Endocarditis in IV drug users

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.

DIAGNOSISThe major Duke criteria are:

•Persistently positive blood cultures with microorganisms consistent with IE (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)

•A single positive blood culture for Coxiella burnetii or IgG antibody titer >1:800

•Echocardiographic evidence of endocardial involvement

The minor Duke criteria are:

•Predisposing heart condition

•Fever

•Vascular phenomena (arterial emboli, septic pulmonary emboli, mycotic aneurysm, Janeway lesions)

•Immunologic phenomena (glomerulonephritis, Osler nodes, Roth spots, rheumatoid factor)

•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.

TREATMENTAntimicrobial 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 dosee

or divided into equal doses q8h for 2 weeks

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)

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)

HIV IN ELDERLY

INTRODUCTIONAIDS 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:

• the use of sildenafil to effectively treat erectile dysfunction and enhance sexual performance may increase risky sexual behavior.

• Additionally, postmenopausal women may be less likely to request that condoms be used as they face no risk of pregnancy.

• Finally, age-associated declines in immunity may place older individuals at higher risk of transmission with each exposure

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, pain in hands or feet (peripheral neuropathy), problems sleeping, muscle or joint pain (myalgias or arthralgias).

Physical exam

Skin: Kaposi’s sarcoma, psoriasis, seborrheic dermatitis, eosinophilic

folliculitis, 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

CLINICAL CONDITIONS THAT MAKE PHYSICIAN SUSPECTUNDIAGNOSED-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)

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

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

HIV TREATMENTa 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)

fusion inhibitors

entry inhibitors

integrase inhibitors

current treatment guidelines have established preferred recommended regimens that include 1 NNRTI + 2 NRTIs or

1 PI + 2 NRTIs.

.

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

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