Treating Community-acquired Bacterial Respiratory Tract Infections: Update on Etiology, Diagnosis, and Antimicrobial Therapy

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Treating Community-acquired Bacterial Respiratory Tract Infections: Update on Etiology, Diagnosis, and Antimicrobial Therapy

J Fam Pract. 2005 April;54(4):357-364

By

Stephen Brunton, MD

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References

1. Whitney CG, Farley MM, Hadler J, et al. for the Active Bacterial Core Surveillance Program of the Emerging Infections Program network. Increasing prevalence of multidrug-resistant Streptococcus pneumoniaein the United States. N Engl J Med. 2000;343:1917-1924.

2. Jacobs MR, Felmingham D, Appelbaum PC, Grüneberg RN; the Alexander Project Group. The Alexander Project 1998-2000: susceptibility of pathogens isolated from community-acquired respiratory tract infection to commonly used antimicrobial agents. J Antimicrob Chemother. 2003;52:229-246.

3. File TM, , Jr. Overview of community-acquired respiratory tract infections. In: Nightingale CH, Ambrose PG, File TM, Jr., eds. Community-Acquired Respiratory Infections: Antimicrobial Management. New York, NY: Marcel Dekker, Inc; 2003;1-30.

4. Ben-David D, Rubinstein E. Appropriate use of antibiotics for respiratory infections: review of recent statements and position papers. Curr Opin Infect Dis. 2002;15:151-156.

5. Gonzales R, Malone DC, Maselli JH, Sande MA. Excessive antibiotic use for acute respiratory infections in the United States. Clin Infect Dis. 2001;33:757-762.

6. Gwaltney JM, , Jr. Acute community-acquired sinusitis. Clin Infect Dis. 1996;23:1209-1225.

7. Niederman MS, Mandell LA, Anzueto A, et al. American Thoracic Society Guidelines for the management of adults with community-acquired pneumonia. Diagnosis, assessment of severity, antimicrobial therapy, and prevention. Am J Respir Crit Care Med. 2001;163:1730-1754.

8. Anon JB, Jacobs MR, Poole MD, et al. Sinus and Allergy Health Partnership Antimicrobial treatment guidelines for acute bacterial rhinosinusitis. Otolaryngol Head Neck Surg. 2004;130:1-45.

9. Snow V, Mottur-Pilson C, Gonzales R. for the American College of Physicians-American Society of Internal Medicine Principles of appropriate antibiotic use for treatment of acute bronchitis in adults. Ann Intern Med. 2001;134:518-520.

10. Mandell LA, Bartlett JG, Dowell SF, File TM, , Jr, Musher DM, Whitney C. Update of practice guidelines for the management of community-acquired pneumonia in immunocompetent adults. Clin Infect Dis. 2003;37:1405-1433.

11. Gonzales R, Bartlett JG, Besser RE, et al. Principles of appropriate antibiotic use for treatment of uncomplicated acute bronchitis: background. Ann Intern Med. 2001;134:521-529.

12. Bishai WR. I>ssues in the management of bacterial sinusitis. Otolaryngol Head Neck Surg. 2002;127:S3-S9.

13. Osguthorpe JD. Adult rhinosinusitis: diagnosis and management. Am Fam Physician. 2001;63:69-76.

14. Lindbaek M, Hjortdahl P, Johnsen UL. Use of symptoms, signs, and blood tests to diagnose acute sinus infections in primary care: comparison with computed tomography. Fam Med .1996;28:183-188.

15. Williams JW, Jr, Holleman DR, Jr, Samsa GP, Simel DL. Randomized controlled trial of 3 vs 10 days of trimethoprim/sulfamethoxazole for acute maxillary sinusitis. JAMA. 1995;273:1015-1021.

16. Anthonisen NR, Manfreda J, Warren CPW, Hershfield ES, Harding GKM, Nelson NA. Antibiotic therapy in exacerbations of chronic obstructive pulmonary disease. Ann Intern Med. 1987;106:196-204.

17. Sethi S. Infectious etiology of acute exacerbations of chronic bronchitis. Chest. 2000;117:380S-385S.

18. Rodriguez-Roisin R. Toward a consensus definition for COPD exacerbations. Chest. 2000;117:398S-401S.

19. Metlay JP, Kapoor WN, Fine MJ. Does this patient have community-acquired pneumonia? Diagnosing pneumonia by history and physical examination. JAMA. 1997;278:1440-1445.

20. Lonks JR. What is the clinical impact of macrolide resistance? Curr Infect Dis Rep. 2004;6:7-12.

21. Sokol W. Epidemiology of sinusitis in the primary care setting: results from the 1999-2000 Respiratory Surveillance Program. Am J Med. 2001;111(suppl 9A):19S-24S.

22. Appelbaum PC. Resistance among Streptococcus pneumoniae: implications for drug selection. Clin Infect Dis. 2002;34:1613-1620.

23. Doern GV, Brueggemann AB, Huynh H, Wingert E, Rhomberg P. Antimicrobial resistance with Streptococcus pneumoniae in the United States, 1997-1998. Emerg Infect Dis. 1999;5:757-765.

24. Doern GV, Brown SD. Antimicrobial susceptibility among community-acquired respiratory tract pathogens in the USA: data from PROTEKT US 2000-01. J Infect. 2004;48:56-65.

25. Pfaller MA, Jones RN. Gatifloxacin phase IV surveillance trial (TeqCES study) utilizing 5000 primary care physician practices: report of pathogens isolated and susceptibility patterns in community-acquired respiratory tract infections. Diagn Microbiol Infect Dis. 2002;44:77-84.

26. Hoban D, Waites K, Felmingham D. Antimicrobial susceptibility of community-acquired respiratory tract pathogens in North America in 1999-2000: findings of the PROTEKT surveillance study. Diagn Microbiol Infect Dis. 2003;45:251-259.

27. Dunbar LM. Current issues in the management of bacterial respiratory tract disease: the challenge of antibacterial resistance. Am J Med Sci. 2003;326:360-368.

28. Garau J. The hidden impact of antibacterial resistance in respiratory tract infection. Clinical failures: the tip of the iceberg? Respir Med. 2001;95(suppl A)-S5-11.

29. File TM, , Jr, Jacobs MR, Poole MD, Wynne B. 546, 547, 548, 549, 550, 551, 556, 557 and 592 Clinical Study Groups. Outcome of treatment of respiratory tract infections due to Streptococcus pneumoniae, including drug-resistant strains, with pharmacokinetically enhanced amoxycillin/clavulanate. Int J Antimicrob Agents. 2002;20:235-247.

30. Amsden GW. Pneumococcal macrolide resistance: myth or reality? J Antimicrob Chemother. 1999;44:1-6.

31. Neuhauser MM, Weinstein RA, Rydman R, Danziger LH, Karam G, Quinn JP. Antibiotic resistance among gram-negative bacilli in US intensive care units. Implications for fluoroquinolone use. JAMA. 2003;289:885-888.

32. Brook I, Gooch WM 3rd, Jenkins SG, et al. Medical management of acute bacterial sinusitis. Recommendations of a clinical advisory committee on pediatric and adult sinusitis. Ann Otol Rhinol Laryngol Suppl. 2000;182:2-20.

33. Benninger MS, Sedory Holzer SE, Lau J. Diagnosis and treatment of uncomplicated acute bacterial rhinosinusitis: summary of the Agency for Health Care Policy and Research evidence-based report. Otolaryngol Head Neck Surg 2000;123:665-667.

34. Snow V, Mottur-Pilson C, Hickner JM. Principles of appropriate antibiotic use for acute sinusitis in adults. Ann Intern Med 2001;134:495-497.

35. Hickner JM, Bartlett JG, Besser RE, et al. Principles of appropriate antibiotic use for acute rhinosinustis in adults. Background. Ann Intern Med 2001;123:498-505.

36. Tankovic J, Bachoual R, Ouabdesselam S, Boudjadja A, Soussy CJ. In-vitro activity of moxifloxacin against fluoroquinolone-resistant strains of aerobic gram-negative bacilli and Enterococcus faecalis. J Antimicrob Chemother. 1999;43 (suppl B):19-23.

37. Andrews JM, Weller TMA, Ashby JP, Walker RM, Wise R. The in vitro activity of ABT773, a new ketolide antimicrobial agent. J Antimicrob Chemother. 2000;46:1017-1022.

38. Cunha BA. Empiric therapy of community-acquired pneumonia: guidelines for the perplexed? Chest. 2004;125:1913-1919.

39. File TM, Jr, Garau J, Blasi F, et al. Guidelines for empiric antimicrobial prescribing in community-acquired pneumonia. Chest 2004;125:1888-1901.

40. Maglio D, Nicolau DP. Antimicrobial efficacy review. Infect Dis. 2004;7:33-36.

41. Sobol SE, Schloss MD, Tewfik TL. Sinus, acute, medical treatment. Available at:http://www.emedicine.com/ENT/ topic337.htm Accessed January 4, 2005.

42. Tse J, Cosep ML, Aminimanizani A, Gill MA. Communityacquired pneumonia. California Pharmacist Winter. 2002;2003:54-65.

43. Full US Prescribing Information for Ketek Available at: http://www.aventis-US.com/PIs/ketek_TXT.html Accessed January 4, 2005.

44. Full US Prescribing Information for Avelox Available at: http://www.univgraph.com/bayer/inserts/Avelox.pdf .Accessed January 4, 2005.

Acute bacterial sinusitis (ABS), acute bacterial exacerbations of chronic bronchitis (ABECB), and community-acquired pneumonia (CAP) are 3 respiratory tract infections (RTIs) in adults that pose a treatment challenge for clinicians in the primary care setting. Each of these conditions requires prompt initiation of therapy to achieve optimal patient outcomes, but diagnosis and selection of treatment typically are made without the benefit of diagnostic tests. Due to increasingly high levels of antibiotic resistance,^1,2 the decision to treat and the selection of therapy are critically important.^3-5

This article briefly reviews the etiology of community-acquired bacterial RTIs, important diagnostic considerations, and current treatment options for patients who have these infections.

Practice recommendations

Most community-acquired respiratory tract infections (RTIs) are not bacterial; therefore, patients do not require antibiotic treatment.
Antibiotic therapy for community-acquired bacterial RTIs, including acute bacterial sinusitis (ABS), acute bacterial exacerbations of chronic bronchitis (ABECB), and community-acquired pneumonia (CAP), is typically empiric and requires careful evaluation of patients and antibiotics.
Common respiratory tract pathogens, including Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis, are becoming increasingly resistant to currently used antibiotics.
To reduce the development of drug-resistant bacteria and maintain their effectiveness, new-generation antimicrobials should be used only to treat infections that have been proven or are strongly suspected to be caused by bacteria.

Community-acquired respiratory tract infections: Viral vs bacterial

The debate regarding whether to prescribe antibiotics for patients with community-acquired RTIs continues, since most of these infections are viral. Approximately 2% of patients with acute sinusitis have a bacterial infection.^4,6 The etiology of acute exacerbations of chronic bronchitis (AECB) is only about 50% bacterial; other causes for these exacerbations include viruses, allergens, and environmental pollutants.³ Among ambulatory patients with CAP, even when diagnostic testing is performed, the causative pathogen cannot be identified in 40% to 50% of patients.⁷ All of these findings support the view that many cases of acute sinusitis, AECB, or CAP are not caused by bacteria and patients with these types of infections will not benefit from antimicrobial therapy. A diagnostic challenge to primary care physicians is determining which patients have a bacterial infection.

Differential diagnosis of bacterial infection in patients with community-acquired respiratory tract infections

National and international guidelines have been developed to assist clinicians in the differential diagnosis of bacterial infections.^7-11

Acute sinusitis

Clinical diagnosis of acute sinusitis is based primarily on medical history, symptoms, and physical findings.¹⁴ A wide range of symptoms may occur in patients with acute sinusitis, as it does in patients with a common cold; TABLE 1shows the symptoms most likely to be associated with sinusitis.¹² No single clinical sign or symptom distinguishes between bacterial and viral causes of acute sinusitis; rather, it is the combination of these signs or symptoms that may lead to the diagnosis of bacterial sinusitis. A history of purulent secretions and symptoms that appear more severe than those typically associated with an upper RTI suggests ABS;¹³ however, purulent discharge alone is not always indicative of a bacterial infection. “Double-sickening,” in which the patient becomes ill and then gets worse, combined with elevation in Creactive protein may indicate a bacterial infection.¹⁴ Williams et al¹⁵ recommended that clinical diagnosis emphasize key features such as maxillary toothache, poor response to over-the counter decongestants or antihistamines, a history of colored nasal discharge, abnormal transillumination, and mucopurulent discharge on examination. A diagnosis of ABS may be made if symptoms persist for more than 10 days, worsen after 5 to 7 days, or are more severe than those normally associated with viral upper respiratory illness.^8,13

TABLE 1

Signs and symptoms associated with community-acquired respiratory tract infections^3,13,14,17

Acute sinusitis
Major	Minor
Facial pain/pressure/fullness* Nasal obstruction/blockage Nasal or postnasal discharge/purulence (by history or physical examination) Hyposmia/anosmia, fever (in acute disease only)† Double-sickening	Headache Fever (other than acute disease) Halitosis Fatigue Dental pain Cough Ear pain/pressure/fullness
Acute exacerbation of chronic bronchitis
Increased
Dyspnea Sputum volume Sputum production
Community-acquired pneumonia
Productive cough, pleuritic chest pain, or dyspnea Fever Tachypnea Tachycardia Altered breath sounds Rales Falls
*Facial pain/pressure alone does not constitute a suggestive history in the absence of another finding listed in the “major” category.
†Fever in acute sinusitis alone does not constitute a suggestive history in the absence of another finding listed in the “major” category.

Acute exacerbations of chronic bronchitis

There is no definitive agreement regarding what constitutes an AECB. Symptoms originally described by Anthonisen et al¹⁶ are commonly used to define AECB: increased cough and sputum, increased sputum purulence, and increased dyspnea over baseline (TABLE 1).¹⁷ A thorough physical and detailed medical history usually are sufficient to diagnose AECB while ruling out conditions such as pneumonia, congestive heart failure, myocardial ischemia, upper RTI, pulmonary embolism, and recurrent aspiration. A chest x-ray or an electrocardiogram may help with differential diagnosis in some patients.^17,18 Nevertheless, determination of whether an acute exacerbation is bacterial or viral may be difficult because many patients with this disease have persistent airway colonization with the same bacteria thought to be responsible for AECB. To help physicians decide if antibiotics are necessary, practice guidelines have stratified patients by type of exacerbation (mild, moderate, or severe) and risk factors (TABLE 2).