Current Trend in URTI

Transcription

1 Current Trend in URTI Dr Chow Chun Kuen Specialist in Otorhinolaryngology

2 Upper respiratory tract infection Nonspecific Most common cause of physician visits & sick leaves Acute infection of noes, sinuses, pharynx, larynx, trachea & bronchi Common cold, pharyngitis, sinusitis, tracheobronchitis Influenza is a systemic illness involving URT

3 Aetiology Viruses: most common rhinovirus, parainfluenza virus, coronavirus, adenovirus, respiratory syncytial virus, influenza Bacteria: Gp A beta-haemolytic strep.(gabhs) causes 10% pharyngitis Strep. Pneumoniae, H. influenza, Moraxella catarrhalis cause sinusitis secondary to viral URTI Transmission by aerosol, droplet, hand contact with infected secretions and subsequent to nose/eye

4 Risk factors Cold winter months: Nov-Mar Overcrowding e.g. school Viral URTI predispose bacterial pharyngitis, sinusitis & tracheobronchitis esp. in nasal & airway allergy, anatomic abnormalities e.g. DNS, immunodeficiency Progress to severe diseases in obese, pregnant, age>65yro, pt with underlying medical condition

5 Symptoms & Signs Onset 1-3 days after exposure Nasal congestion, sneezing & sore throat Conjunctivitis (adenovirus) Fever w/o cough (GABHS pharyngitis) Purulent rhinorrhoea, unilateral facial pain, toothache >2 wks (bacterial rhinosinusitis) Cough or wheeze > 1/52 ( tracheobronchitis)

6 Influenza Influenza A virus Epidemics spread from schoolchildren to their family Antigenic drift: human lack of immunity against mutated virus->annual epidemics Antigenic shift: from swine/birds to human virus -> pandemics High fever, headache, myalgia, dry cough, fatigue & malaise In elderly: confusion, somnolence, lack of sneezing

7 Diagnosis Clinical diagnosis Nasopharyngeal swab x rapid antigen detection or PCR assay of influenza are only in pt. with specific antiviral therapy Throat swab x rapid antigen detection of GABHS Nasoendoscopy + middle meatal swab culture in sinusitis

8 Radiology Lateral neck XR in patients with stridor (epiglottis) CXR if cough >3/52 or patients with other comorbidity (pneumonia) CT scan of sinus in patients with sinusitis who do not respond to treatment

9 CT PNS

10 Treatment Self limiting in viral URTI Symptomatic treatment Lifestyle Modification Rest Voice rest in hoarseness Benefit of regular exercise: reduce risk of common cold, also reduce illness severity Increase fluid intake: thinning of respiratory secretion

11 Symptomatic Treatment Nasal symptoms: Decongestant (oxymetazoline) : only effective initially, repeated use may result in a rebound phenomenon(rhinitis medicamentosa)after discontinuation Anticholinergic agents (ipratropium bromide): mucosal irritation 1st-generation antihistamines (chlorpheniramine maleate) : sedating effect in driving cars or operating heavy machinery, but desirable in night symptoms.

12 Symptomatic Treatment Antitussives and expectorants in URIs: controversial. NSAIDs: relieving fever, headache, and malaise, but gastrointestinal irritation. Steam inhalation: temporary relief of throat symptoms. Camphor( 樟腦 ) and menthol: temporary relief of various URI symptoms. Mast cell stabilizers (cromolyn sodium) prevents asthma attacks, but their role in treating URIs remains unknown. Topical intranasal steroids (mometasone furoate) benefit in acute sinusitis,esp. in high doses for 21 days. Systemic steroids should not be used for the treatment of URIs.

13 Gargle Role of antiseptic gargle Prevention of URTIs remains a major public health concern Gargling with water in healthy people was found to result in a 36% reduction in the incidence of URTIs. Gargling with tap water, green tea or functional water was found to reduce the odds ratio for fever onset in children. In Japan, current guidelines recommend gargling as one of the preventive measures in the control of influenza pandemic.

14 Vitamin C Role of Vitamin C for the treatment of URIs controversial in numerous studies Large doses of vitamin C are necessary to achieve its beneficial effect as an antioxidant in activated leukocytes. Average benefit in studies using 2 to 4 g/day of vitamin C has been a decrement of about half a day (15%) in the duration of illness. Doses >4 g/day have been associated with diarrhea.

15 Zinc Role of zinc salts: controversial Duration of illness: reduced by 1 day in studies that showed benefit. started within 24 to 48 hours of the onset of cold symptoms. ionic bioavailability of zinc salts: important for beneficial effect. Bad taste (80%) in zinc lozenges, nausea (20%) intranasal zinc gel: same beneficial effect with significantly fewer side effects, anosmia

16 Antibiotics Antibiotics often inappropriately prescribed for URTI, esp. in viral pharyngitis >2x increase in bacterial resistance Allergic drug reactions are common in antibiotics Drug interaction e.g concurrent use of warfarin and any antibiotic is associated with an increased risk of bleeding Patients education about the self-limited nature of most URIs and the hazards of inappropriate use of antibiotics for the individual and the community.

17 Antibiotics Cough productive of yellow sputum, sore throat, fever, and colored nasal discharge: not a reliable marker of the presence of bacteria. Poor predictive value in efficacy of antibiotics. Patient satisfaction is more related addressing patients concerns than giving antibiotics. Alterative approach: giving a prescription for antibiotic, with instructions to use it only if symptoms fail to improve after 3 days

18 Pharyngitis Patients with clinical and epidemiologic features consistent with GABHS pharyngitis should be started on antibiotics pending microbiologic confirmation. Oral penicillin or erythromycin (in penicillinallergic persons), given for 10 days, remains the preferred agent. No resistance to penicillin has been reported so far in GABHS-related pharyngitis patients.

19 Rhinosinusitis Symptomatic treatment to patients with mild-to moderatesinusitis, which are mostly viral. Topical and oral decongestants : to alleviate symptoms. Topical nasal corticosteroids decrease inflammation of the nasal mucosa Antihistamines may have a minor role in treating allergic acute rhinosinusitis, but are not indicated in nonatopic patients. Isotonic saline nasal irrigation is effective. RCT showed that antibiotics should not be prescribed for mild-tomoderate sinusitis within the first week of the illness, because of insignificant clinical improvement, complications or recurrence, but with an 80% increased incidence of adverse events; particularly diarrhea.

20 Rhinosinusitis Moderate or severe acute bacterial rhinosinusitis: symptoms >10 days without improvement severe symptoms, such as fever >39 C, purulent nasal discharge, or facial pain lasting 3-4 consecutive days double sickening illness characterized by initial improvement of a typical viral URI that lasted 5-6 days, followed by worsening of symptoms, identify patients likely to have acute bacterial rather than viral rhinosinusitis. Empiric antimicrobial therapy should be initiated

21 Rhinosinusitis Current guidelines for treatment of acute bacterial rhinosinusitis recommend amoxicillin-clavulanate be used as first-line empiric therapy High rates of penicillin-resistant Streptococcus pneumoniae, and Haemophilus influenzae. High-dose (2 grams orally twice daily for adults) amoxicillin-clavulanate is recommended for patients >65 yro geographic regions with high endemic rates (>10%) of invasive penicillin-nonsusceptible Streptococcus pneumoniae, those with severe infection, attendance at daycare, hospitalization within the preceding 5 days, antibiotic use within the preceding month, who are immunocompromised.

22 Rhinosinusitis Macrolides, trimethoprim-sulfamethoxazole, and second-generation cephalosporins are no longer recommended due to high rates of resistance among Streptococcus pneumoniae, and Haemophilus influenzae. Fluoroquinolones (moxifloxacin and levofloxacin), or a combination of an oral third-generation cephalosporins (cefixime or cefpodoxime) plus clindamycin are appropriate second-line agents. Patients who improve after 3-5 days of initiating a first-line agent should complete 5-7 days of antimicrobial therapy. Patients who do not improve after 3-5 days of initiating a first-line agent should be switched to a second-line agent. Patients who improve after 3-5 days of either initiating a secondline agent from the outset, or after switching from a first-line to a second-line agent should be treated for 7-10 days.

23 Tracheobronchitis Antibiotics is not recommended, because most cases are viral and thus resolve spontaneously Antibiotic with no effect on the rate of recovery of acute cough Persistent cough in who report exposure to a patient with confirmed or suspected pertussis, erythromycin or trimethoprimsulfamethoxazole should be administered for 14 days. Bronchodilators offer symptomatic relief for cough

24 Influenza Mild and nonfebrile influenza-like illness should not be treated with antiviral agents. Adamantanes, amantadine, and rimantadine, are M2 ion channel blockers that are not recommended for clinical use due to high incidence of GI and neuropsychiatric side effects, and resistance of influenza strains. Neuraminidase inhibitors (NAIs), oseltamivir and zanamivir, are active against both influenza A and B, fewer side effects and less viral resistance all patients hospitalized for influenza should receive NAI In high-risk populations, NAI may reduce mortality, hospitalization, and duration of symptoms. Started within 1-2 days of onset of illness, most studies have shown a 1-2 days reduction in the duration of illness.

25 Indication of Referral Symptoms refractory to medical treatment Signs of upper airway obstruction Suppurative complications of URIs: Peritonsillar abscess, Mastoiditis, Sinusitis refractory to medical treatment should be referred to ENT Specialist

26 Endoscopic Sinus Surgery

27 Treatment Outcome Most URIs resolve spontaneously in 3 to 10 days GABHS pharyngitis, moderate or severe suspected acute bacterial rhinosinusitis, and moderate or severe influenza, antimicrobial therapy generally results in symptom relief, and resolution of illness 1 to 2 days sooner than if symptomatic measures alone are used. Prompt antibiotics decreases contagion and suppurative complications, such as peritonsillar abscess, as well as immunologic complications, such as rheumatic fever and glomerulonephritis. Benefits of anti-influenza drugs are more pronounced in patients presenting with more severe illness. NAIs have also shown a reduction in the incidence of complications from influenza in the frail older population and in patients with underlying medical conditions, such as chronic obstructive pulmonary disease or cardiomyopathy.

28 Prevention & Screening Frequent hand washing remains the most important preventive measure for most URIs Simple measures, such as covering the mouth and nose while sneezing or coughing with tissue napkin (not with one s hand), or sneezing in one s axillary or cubital fossa if a tissue napkin is not readily available, can decrease contagion. Aqueous iodine can prevent viral transmission when applied to the hands of patients with viral URIs Benefits of adequate sleep reduce the risk of cold illness in a rhinovirus challenge study

29 Prevention & Screening Prophylactic antibiotics cannot prevent the development of bacterial superinfection of viral URIs and have no benefit in acute, clear or purulent rhinitis. Vitamin C is not recommended for prevention of URIs in the general community. Marathon runners, skiers, or soldiers, who are exposed to significant cold or physical stress, prophylactic vitamin C may reduce the incidence of colds by 50% and shorten the duration of colds by 8% in adults (approximately 0.6 day).

30 Prevention & Screening Trivalent inactivated intramuscular influenza vaccine the flu shot is cost-saving interventions in medicine today. 30% to 50% reduction of respiratory illnesses, physician visits, and sick leave in vaccinated healthy adults, reduction in hospitalization related to acute worsening of chronic obstructive pulmonary disease or congestive heart failure, and death from any cause among vaccinated older persons. Recent data suggest lesser benefits than previously demonstrated. Influenza vaccination is currently recommended for all U.S. population age 6 months from early fall through early spring. Redness and soreness at the site of injection, fever, malaise, and myalgia(10%)

31 Contraindication: Prevention & Screening prior severe allergic reaction to influenza vaccine History of Guillain-Barr Syndrome that had developed within 6 weeks of receipt of previous influenza vaccine Vaccination of persons with moderate to severe acute febrile illness should be postponed until symptoms resolve. Patients with mild URIs can still receive the vaccine.

32 Prevention & Screening Live-attenuated, cold-adapted, intranasal influenza vaccine is as effective as the inactivated vaccine, avoid an injection. Only approved for healthy persons aged 2 to 49 years. Shedding of live-attenuated virus within 1 week after receiving this vaccine, Health care providers and household contacts of severely immunocompromised patients should only receive the inactivated vaccine to avoid the theoretical risk of virus transmission causing disease.

33 Prevention & Screening URIs in children caused by H. influenzae type B have been eliminated by the widespread use of the H. influenzae type B vaccine, but cases of nontypable H. influenzae continue to occur in adults. 23-valent pneumococcal polysaccharide vaccine has been on preventing bacteremic pneumonia and meningitis in older adults Reduction in invasive pneumococcal disease in adults since the introduction of the pediatric conjugated pneumococcal vaccine Oral live attenuated adenovirus vaccine is available but is restricted for military use.

34 Prevention & Screening Chemoprophylaxis should not be considered as a substitute for vaccination 10-day course for post exposure prophylaxis for immunocompromised individuals exposed to a patient with confirmed influenza. 6-weeks course for seasonal prophylaxis should be reserved for influenza outbreaks before vaccine available. Risk of resistant virus strain development

35 Special populations Patients who are immunocompromised because of disease or medications are at higher risk for complications caused by URIs. Special attention should be paid to prevention of these infections, if possible, and to treat early to limit morbidity.

36 Conclusions Viruses cause most URIs. Penicillin is recommended for patients with GABHS pharyngitis, Amoxicillin-clavulanate for those with moderate or severe suspected acute bacterial rhinosinusitis. Patients with moderate or severe influenza, those with underlying medical conditions, and those hospitalized for influenza should be treated with a neuraminidase inhibitor.

37 Summary Most URIs are viral in origin. Diagnosis is mainly based on clinical manifestations. Adults with clinical findings suggestive of GABHS pharyngitis should have a pharyngeal rapid streptococcal antigen detection test before considering antimicrobial therapy. Sinus puncture and sinus CT are not recommended for the diagnosis of uncomplicated sinusitis. If pneumonia is unlikely on clinical grounds, chest radiography is not recommended for patients with acute tracheobronchitis. A nasopharyngeal swab to confirm influenza by rapid antigen detection test or PCR is recommended before initiating antiviral treatment for patients with suspected influenza, or antiviral chemoprophylaxis for their household contacts.

38 Summary Symptomatic Tx is the mainstay of treatment for most URIs. Vitamin C and zinc remain controversial. Antibiotics should be avoided in patients with a common cold, mild acute rhinosinusitis, or acute bronchitis, but should be prescribed to patients with GABHS pharyngitis and to moderate or severe suspected acute bacterial rhinosinusitis. Penicillin is the recommended treatment for GABHS pharyngitis. Amoxicillin-clavulanate is the recommended first-line agent for treatment of suspected acute bacterial rhinosinusitis. Patients with moderate or severe influenza, those with underlying medical conditions who develop influenza, and those hospitalized for management of influenza should be treated with a NAI.