Study of Community Acquired Pneumonia Aetiology (SCAPA) in Adults Admitted to Hospital: Implications for Management Guidelines

Home , Chlamydia pneumoniae, Pneumococcal infection

296 Thorax 2001;56:296–301 Study of community acquired pneumonia aetiology (SCAPA) in adults admitted to hospital: implications for management guidelines

W S Lim, J T Macfarlane, T C J Boswell, T G Harrison, D Rose, M Leinonen, P Saikku

Abstract Community acquired pneumonia (CAP) is Background—Since the last British study common in the UK, aVecting 250 000 adults of the microbial aetiology of community per year of whom 83 000 (33%) are admitted acquired pneumonia (CAP) about 20 to hospital (67% for patients aged 65 years and 1 2–4 years ago, new organisms have been iden- over). Mortality ranges from 6% to15%. tified (for example, Chlamydia pneumo- Initial antibiotic management of CAP is niae), new antibiotics introduced, and empirical and dependent on a clear under- fresh advances made in microbiological standing of the likely pathogens. In the UK this techniques. Pathogens implicated in CAP knowledge is based on studies performed in the 1970s and early 1980s.5 The largest study, con- in adults admitted to hospital in the UK ducted by the British Thoracic Society (BTS) using modern and traditional microbio- in 1982, excluded adults over 74 years of age, logical investigations are described. thus missing the group of patients who carry Methods—Adults aged 16 years and over the burden and mortality of CAP.3 admitted to a teaching hospital with CAP In the last two decades a number of factors over a 12 month period from 4 October have potentially aVected the pattern of adult 1998 were prospectively studied. Samples Respiratory Infection CAP in the UK. The increasing age of the Research Group, of blood, sputum, and urine were col- population, often with co-morbid illnesses or Respiratory Medicine, lected for microbiological testing by resident in residential and nursing homes, has Nottingham City standard culture techniques and new raised concerns of Gram negative enteric Hospital, Hucknall serological and urine antigen detection bacterial infection in CAP.6 Concerns of Road, Nottingham NG5 1PB, UK methods. antibiotic resistance and the emergence of W S Lim Results—Of 309 patients admitted with “new” pathogens such as Chlamydia pneumo- J T Macfarlane CAP, 267 fulfilled the study criteria; 135 niae, implicated in 3–18% of cases of CAP (50.6%) were men and the mean (SD) age elsewhere,7–9 has led to the promotion of Department of was 65.4 (19.6) years. Aetiological agents fluoroquinolones and newer macrolides for the Medical Microbiology treatment of CAP.10 T C J Boswell were identified from 199 (75%) patients (one pathogen in 124 (46%), two in 53 The impact of these changes on the micro- Department of (20%), and three or more in 22 (8%)): bial aetiology of CAP in the UK and how they Diagnostic Radiology Streptococcus pneumoniae 129 (48%), should influence new management guidelines D Rose influenza A virus 50 (19%), Chlamydia is unknown. We have performed a large pneumoniae 35 (13%), Haemophilus in- prospective study of the aetiology of CAP and Respiratory and the outcome in adults admitted to hospital fluenzae 20 (7%), Mycoplasma pneumo- Systemic Infection using a wide range of microbiological investiga- Laboratory, Central niae 9 (3%), Legionella pneumophilia 9 tions. Public Health (3%), other Chlamydia spp 7 (2%), Laboratory, Colindale, London NW9 5EQ, UK Moraxella catarrhalis 5 (2%), Coxiella T G Harrison burnetii 2 (0.7%), others 8 (3%). Atypical Methods pathogens were less common in patients All adults aged 16 years and over admitted to a National Public Health aged 75 years and over than in younger large teaching hospital (Nottingham City Hos- Institute, Department patients (16% v 27%; OR 0.5, 95% CI 0.3 to in Oulu, FIN-90101 pital) over a 12 month period from 4 October Oulu, Finland 0.9). The 30 day mortality was 14.9%. 1998 with CAP were eligible for inclusion in M Leinonen Mortality risk could be stratified by the the study. The hospital shares all unselected presence of four “core” adverse features. adult medical admissions on a daily basis Department of Three of 60 patients (5%) infected with an equally with the University Hospital in Not- Medical Microbiology, atypical pathogen died. tingham, both covering a population of about University of Oulu, FIN-90401 Oulu, Conclusion—S pneumoniae remains the 700 000. Finland most important pathogen to cover by All patients admitted with a provisional P Saikku initial antibiotic therapy in adults of all diagnosis of CAP were identified in the admis- ages admitted to hospital with CAP. sions unit where standardised clinical data and Correspondence to: investigations were obtained. CAP was defined Dr J T Macfarlane Atypical pathogens are more common in john.macfarlane@ younger patients. They should also be cov- as the presence of an acute illness of 21 days or nottingham.ac.uk ered in all patients with severe pneumonia less duration with: (1) features of a lower respiratory tract infec- Received 25 August 2000 and younger patients with non-severe Returned to authors infection. tion including: 23 October 2000 (Thorax 2001;56:296–301) (a) two or more of: new or increasing Revised version received cough, sputum production, shortness of 24 November 2000 Accepted for publication Keywords: adult community acquired pneumonia; breath, wheeze, chest pain, new focal or 18 December 2000 pathogens; aetiology; severity assessment diVuse signs on chest examination;

www.thoraxjnl.com Study of community acquired pneumonia aetiology (SCAPA) in adults admitted to hospital 297

Table 1 Criteria for microbiological diagnosis

Organism Diagnostic criteria All bacteria Isolation from blood processed in Bactec 9240 system or from pleural fluid, bronchoscopic aspirates, or post mortem lung aspirates S pneumoniae, H influenzae or M catarrhalis infection (a) Isolation from washed and diluted sputum in significant numbers by semiquantitative culture or (b) for S pneumoniae: • Pneumococcal antigen (PCA) detected in urine (BINAX-NOW kit, results read at 60 minutes) or in sputum by countercurrent immunoelectrophoresis (CIE) or (c) Serological criteria for S pneumoniae: • >3-fold rise in antibody titre against C-polysaccharide (CPS) or >2-fold rise against pneumolysin (PLY), pneumococcal surface antigen A (PsaA)22 or PLY-, PsaA- or CPS-specific immune complexes detected23 (d) Serological criteria for H influenzae or M catarrhalis: • >3-fold rise in antibody titre24 Infection with other bacteria including Gram negative The predominant organism in the sputum Gram stain in addition to isolation from washed and diluted enterobacteria (GNEB) and Staph aureus sputum in significant numbers by semiquantitative culture Atypical and viral pathogens C pneumoniae (a) at least 3-fold rise in IgG or IgA antibodies or (b) presence of IgM antibody, using EIA kit (Labsystems, Helsinki, Finland) L pneumophila Isolation of organism from respiratory samples or Legionella antigen detected in urine by Biotest kit25 26 or 4-fold or greater rise in immunofluorescent antibody titre to >64 using formalised yolk sac antigen to L pneumophila serogroup 1 M pneumoniae, Chlamydia spp, C burnetti, influenza A and 4-fold or greater antibody rise or a single titre of >128, by complement fixation test B, respiratory syncytial virus (RSV) and adenoviruses

Serum samples were tested at the National Public Health Institute, Department in Oulu, Finland for antibody responses to C pneumoniae, H influenzae, M catarrhalis, and S pneumoniae. Urine antigen testing was performed in conjunction with the Central Public Health Laboratory, Colindale, London, UK. The criteria used to define infection in the 1982 BTS study were followed, updated for new investigations and pathogens.3 (b) one or more constitutional symptoms radiographs were reviewed by an experienced including fever, confusion, sweating, head- radiologist (DR) blinded to patient details to aches, aches and pains, sore throat or confirm the radiographic study entry criteria. coryza; All patients were seen regularly in hospital and (2) radiographic shadowing on an admission after discharge until their clinical and radio- chest radiograph consistent with infection logical features had stabilised. Patients who and which was neither pre-existing nor of failed to attend were visited at home. A repeat other known cause; and chest radiographic and blood sample for (3) treatment with antibiotics for pneumonia serological testing were obtained at follow up. by the attending physician. The main outcome measure was 30 day Patients were excluded if the pneumonia mortality. was (a) not the primary cause for hospital admission, (b) an expected terminal event or LABORATORY INVESTIGATIONS: CRITERIA FOR (c) distal to bronchial obstruction (for exam- MICROBIOLOGICAL DIAGNOSIS ° ple, from lung cancer). Patients with tuberculo- Samples were held at 4 C and transported rap- sis and HIV infection were excluded as were idly to the Nottingham Public Health Labora- those who had been in hospital within the pre- tory Service (PHLS) laboratory for standard vious 10 days, were immunocompromised and specialised investigations as previously (received chemotherapeutic agents during 6 described and summarised in table 1. The cri- month period before admission or more than teria used to define infection in the 1982 BTS the equivalent of prednisolone 10 mg daily for study were followed but updated for new techniques (table 1).3 The pathogens included in at least 3 months before admission), or had the term “atypical” pathogen are specified in previously been entered in the study. Comor- table 3. Results for the BINAX-NOW pneu- bid illness was defined as the presence of any of mococcal antigen detection kit were read at 60 the following conditions for which the patient minutes instead of 15 minutes (as recom- was under active medical supervision or was mended by the manufacturers), based on the receiving treatment at the time of hospital increased sensitivity of the 60 minute reading admission: chronic lung disease, cardiac dis- and no apparent diVerence in specificity ease (ischaemic heart disease, cardiac failure, (100%) determined in a series of 50 cases of hypertension, atrial fibrillation), cerebrovascu- non-pneumococcal proven pneumonias (au- lar disease (including previous transient ischae- thors, unpublished data). mic attacks), cognitive impairment, diabetes mellitus, chronic liver disease, chronic renal STATISTICAL ANALYSIS disease, and inflammatory rheumatological Data were analysed using SPSS version 8.0 for disorders (excluding osteoarthritis). Mental Windows. ÷2 or Fisher’s exact tests were used to confusion was defined as an abbreviated men- compare categorical variables. Multivariate tal test score of 8 or less and severe pneumonia analysis was performed by stepwise logistic was defined using the modified BTS (mBTS) regression. Results are expressed as odds ratios 7 severity rule. For the benefit of the discussion, (ORs) with 95% confidence intervals (CI) and patients aged 75 years and over are termed p values, taking p<0.05 as the level of statistical “elderly”. The study was approved by the Not- significance. tingham City Hospital ethics committee. Patients were seen within 24 hours of admis- Results sion by a study investigator to confirm study Of 309 patients diagnosed with CAP on entry criteria and informed consent. All chest admission, eight were unwilling to participate

www.thoraxjnl.com 298 Lim, Macfarlane, Boswell, et al

Table 2 Characteristics and outcome of study cohort SPECIMEN COLLECTION (n=267) Specimens obtained included blood cultures prior to antibiotics in hospital from 225 (84%) Characteristic No (%) patients, acute serum from 250 (94%) and fol- Age (years) low up serum from 204 (90%) survivors, urine Mean (SD) 65.4 (19.6) Range 18–97 from 214 (80%) patients, and sputum within Age groups (years) 24 hours of admission from 155 (58%) 18–44 49(18) patients, 128 of whom were tested for pneumo- 45–64 59(22) 65–74 47(18) coccal antigen. 75–84 68(25) 85+ 44(16) AETIOLOGICAL AGENTS IDENTIFIED Men 135(51) Admitted from nursing home 22(8) Aetiological agents were found in 199 (75%) Smoking status patients: one pathogen in 124 (46%), two in 53 Current 73(27) Ex-smoker (>6 months) 100(37) (20%), and three or more in 22 (8%). Never 80(30) Altogether, 144 (54%) bacterial, 62 (23%) Not known 14(5) viral, and 60 (22%) atypical pathogens were Alcohol consumed None 158(59) detected (table 3). <21 units/week 76 >21 units/week 15(6) Bacterial pathogens Not known 18 Vaccination status The methods of diagnosing the 129 (48%) Influenza vaccine (in last 12 months) 76(28) pneumococcal cases are shown in detail in Pneumococcal vaccine (in last 10 years) 39(14.6) table 4. Only one penicillin resistant strain was Comorbid illnesses None 83(31) isolated from blood culture of one patient. Chronic lung disease 82(31) Pneumococcal infection was diagnosed in 90 of Ischaemic heart disease 33(12) 163 patients (55%) who had not received any Cardiac failure 12(5) Cerebrovascular disease 30(11) antibiotics before admission compared with 39 Diabetes mellitus 22(8) of 104 (37%) who had been treated with anti- Dementia 22(8) Cancer 15(6) biotics (OR 2, 95% CI 1.3 to 3.4, p=0.004). Chronic liver disease 2(0.7) Staphylococcus aureus was isolated from the Antibiotics prior to hospital admission 104(39) blood of two patients, both of whom had influ- Amoxycillin 57 Macrolide 22 enza A infection and required treatment in the intensive care unit within 24 hours of admission. Haemophilus influenzae and Moraxella catarrhalis were diagnosed by sputum culture and 34 were subsequently found not to fulfil in 11 (four ampicillin resistant) and two (one study entry criteria, leaving 267 patients in the ampicillin resistant) cases, respectively, and by study cohort, 112 (41%) of whom were elderly serological testing in 10 and four cases, respec- (table 2). Of the 267 patients, 190 (71%) were tively. admitted over the winter (October to March), Of the four cases who fulfilled our criteria for most in December and January (n=88 cases aerobic Gram negative enterobacterial infec- (33%)). Comorbid illnesses were more com- tion, both Klebsiella spp and Escherichia coli mon in the elderly than in younger patients were isolated from blood culture in one patient. (86% v 59%; OR 4.1, 95% CI 2.2 to 7.5, Pseudomonas aeruginosa was identified by Gram p<0.001). stain and culture from sputum in three patients with chronic lung disease and prior antibiotic Table 3 No (%) of pathogens detected in 267 adults studied according to age use, two of whom recovered without receiving antipseudomonal therapy which strongly Total (%) Age <75 years Age >75 years suggests that, in these cases, Pseudomonas was Pathogen (n=267) Died (%) (n=155) (n=112) not an aetiological agent. Details of the three Bacterial pathogens 144 (54) 19 (13) 88 (57) 56 (50) patients with anaerobic infection are given in Streptococcus pneumoniae 129 (48) 18 (14) 80 (52) 49 (43) table 3. Haemophilus influenzae 20 (7) 1 (5) 11 (7) 9 (8) Moraxella catarrhalis 5 (2) 0 (0) 1 (0.6) 4 (4) Staphylococcus aureus 4 (1.5) 2 (50) 2 (1) 2 (2) Atypical and viral pathogens GNEB* 4 (1.4) 1 (25) 3 (1.9) 1 (0.9) Chlamydia pneumoniae was identified serologi- Anaerobes† 3 (1.1) 0 (0) 2 (1) 1 (0.9) cally in 35 (13%) cases, more commonly in the Atypical pathogens 60 (22) 3 (5) 42 (27) 18 (16) winter (31 of 190 patients) than in the summer Chlamydia pneumoniae 35 (13) 2 (6) 20 (13) 15 (13) Mycoplasma pneumoniae 9 (3) 0 (0) 8 (5) 1 (0.9) (four of 77; p=0.015). Legionella pneumophila 9 (3) 1 (11) 8 (5) 1 (0.9) Legionella pneumophila infection was diag- Chlamydia spp‡ 7 (2) 0 (0) 5 (3) 2 (2) Coxiella burnetti 2 (0.7) 0 (0) 2 (1) 0 (0) nosed in nine patients (by urine antigen detec- Viral pathogens 62 (23) 6 (10) 36 (23) 26 (23) tion in seven and serological testing in eight). Influenza virus A 50 (19) 6 (12) 30 (19) 20 (18) Three cases were associated with travel. There Influenza virus B 2 (1) 0 (0) 0 (0) 2 (2) was no seasonal variation. Only two patients Respiratory syncytial virus 11 (4) 0 (0) 6 (4) 5 (4) Rhinovirus 2 (0.7) 0 (0) 2 (1.3) 0 (0) fulfilled the admission criteria for having severe Adenovirus 1 (0.4) 0 (0) 1 (0.6) 0 (0) pneumonia and both survived. Pathogen not identified 68 (25) 15 (22) 33 (21) 35 (31) Atypical pathogens were found less often in Pathogens were identified from bronchial washings in two patients (L pneumophilia, influenza A), elderly than in younger patients (16% v 27%; post mortem lung tissue in one (S pneumoniae), and pleural fluid in one (Bacteroides spp). OR 0.5, 95% CI 0.3 to 0.9, p=0.03) both in the *Gram negative Enterobacteriaceae (details in text). group as a whole and when divided into those †Bacteroides spp isolated from pleural fluid in one patient, Fusobacterium necrophorum from blood of a patient with dental caries, and Gemella morbilloram from blood of another patient. with severe and non-severe infection (table 5). ‡Excluding those found to be diagnostic in C pneumoniae assays. Their identification was not influenced by prior

www.thoraxjnl.com Study of community acquired pneumonia aetiology (SCAPA) in adults admitted to hospital 299

Table 4 Value of pneumococcal diagnostic tests for the 129 patients diagnosed as having unit was 1 day; 12 (71%) were admitted within pneumococcal infection the first 24 hours of admission. The mBTS severity prediction rule was 78% No (%) positive sensitive and 68% specific (negative predictive Sole means value (NPV) 95%) at predicting death in com- Sensitivity* of diagnosis Prior antibiotics No prior antibiotics 3 Diagnostic test (%) (no of patients) (n=104) (n=163) p value parison with the BTS original prediction rule which was 60% sensitive and 73% specific Blood culture 9/114 (8) 3 0 9 0.01 (NPV 91%). For elderly patients aged 75 years Urine antigen 69†/114 (61) 31 17 (16) 52 (32) 0.005 or over the sensitivity (77%) and NPV (86%) Serology 78/123 (63) 36 26 (25) 53 (33) 0.19 Sputum culture 9/73 (12) 3 1 8 0.08 of the mBTS rule remained high, although Sputum CIE 15/66 (23) 3 4 11 0.3 specificity was reduced to 53%. Seven of 90 CIE = countercurrent electrophoresis. patients (8%) with one of the four features in *Sensitivity = proportion of patients with one or more positive pneumococcal test. the mBTS rule died compared with 14 of 61 †49 were positive at 15 minutes. Of the remaining 20, seven had pneumococcal infection (23%) with two features, 12 of 36 (33%) with diagnosed by other tests. three features, five of six (83%) with four Table 5 Relationship between infection and atypical pathogen, age, and severity features, and two of 74 (2.7%) with no features present (÷2 test for trend: odds ratio 2.8, 95% Number with atypical pathogen detected CI 1.96 to 4.0, p<0.001). Age <75 years Age >75 years Total (n=60) (n=42) (n=18) Discussion This is the first UK study to employ a wide Total no of patients 267 155 112 Total with atypical pathogen 60 (22%) 42 (27%) 18 (16%) range of diagnostic tools to identify the Proportion with severe infection who aetiological agents in adult CAP, including C had an atypical infection 22/103 (21%) 11/41 (27%) 11/62 (18%) pneumoniae, and to include patients aged 75 Proportion with non-severe infection who had an atypical infection 38/164 (23%) 31/114 (27%) 7/50 (14%) years and above. The high pathogen detection Severe CAP (died) 22 (2) 11 (0) 11 (2)* rate (75% of cases) reassuringly found no sub- Non-severe CAP (died) 38 (1) 31 (1)† 7 (0) stantial shift in the causes of CAP or antibiotic *Both patients had C pneumoniae as the sole pathogen detected. One man aged 90 died 7 days after sensitivity in the UK over the last 20 years, with hospital admission and another aged 78 died at home on day 29 having been previously discharged penicillin sensitive S pneumoniae still the well. predominant causative agent in nearly half of †Travel associated L pneumophilia infection. cases.2–4 This is an important finding when antibiotic use. Only three of the 60 patients reviewing management guidelines for this (5%) with infection by an atypical pathogen common condition, particularly as perceived died, two of whom had C pneumoniae infection changes in the pattern of CAP have led to and one Legionella. changes in national antibiotic guidelines else- Of the 50 cases with influenza A virus infec- where.10 tion, 38 (76%) occurred in December and Pneumococcal infection was diagnosed less January. Respiratory syncytial virus (RSV) was commonly in patients who had received antibi- the second most common viral pathogen iden- otics before admission, presumably due to tified. Of the 11 RSV cases, at least one other decreased sensitivity of microbiological tests in pathogen was identified in nine (a bacterial this circumstance.3 None of the bacteraemic pathogen in eight and influenza A virus in one). patients had received prior antibiotics. If prior antibiotic use is taken into account, then the Mixed infections true estimate of pneumococcal incidence is In infections in which Streptococcus pneumoniae 55%, similar to the 1982 BTS study. was identified, co-pathogens were diagnosed in This is the first UK report on C pneumoniae 60 (47%) patients (influenza A virus in 25, C infection in adult CAP and it was identified as pneumoniae in 20, H influenzae in nine, other the second most common pathogen. However, atypical pathogens in four, and other viral C pneumoniae was frequently found in mixed pathogens in 11). Where C pneumoniae infec- infections, in over half of the cases with S tion was detected, a co-pathogen was diag- pneumoniae, as reported in other coun- nosed in 26 (74%) cases (S pneumoniae in 20, tries.81112 Pathogens such as C pneumoniae influenza A virus in six, H influenzae in four, may play a role in promoting other bacterial other bacterial pathogens in four, and other infection through their eVect on ciliated viral pathogens in one). Overall, of 144 patients epithelial cells.13 The evidence regarding the in whom infection with a bacterial pathogen importance of C pneumoniae as a pathogen is was diagnosed, an atypical pathogen was also conflicting. Some studies report that outcome identified in 30 (21%) cases and a viral patho- is not aVected when beta-lactam antibiotics gen in 41 (28%) cases. alone are used for patients with evidence of C pneumoniae infection.814 By contrast, studies CLINICAL OUTCOME from Finland have shown that mixed pneumo- Thirty day mortality was 15% (40 patients); 35 coccal and C pneumoniae infections cause patients died during hospital admission, seven more severe CAP than that associated with within the first 24 hours, 12 within the first 2 either pathogen alone.11 14 Our study did not days, and 22 within the first 4 days. The find this (data not shown). The number of median length of stay in survivors was 7 days patients fulfilling the criteria for severe infec- (1st and 3rd quartile values 4 and 11 days, tion were similar for these three groupings. respectively). Of 17 (6%) patients admitted to The overall mortality in patients with pneu- the intensive care unit, five (30%) died. The mococcal infection was much higher than in median time to admission to the intensive care those infected with C pneumoniae (14% v 6%)

www.thoraxjnl.com 300 Lim, Macfarlane, Boswell, et al

and no patients with mixed pneumococcal and of all ages admitted with CAP and this should C pneumoniae infection died. However, two be covered eVectively by the chosen empirical elderly patients with C pneumoniae infection antibiotic. Ampicillin resistant bacteria are alone died. Outbreaks associated with signifi- uncommon and concerns regarding Gram cant mortality have been reported in homes negative enterobacterial infections in the eld- for the elderly in the USA.15 erly seem unfounded. Our study supports the view that, unlike Our study confirmed that pneumococcal, other atypical infections, C pneumoniae infec- Haemophilus, and staphylococcal infections are tion aVects adults of all ages, usually as a the usual bacterial pathogens implicated in co-pathogen, and can be associated with severe fatal CAP and such pathogens should always infection and occasionally death. This provides be covered by initial antibiotic therapy for support to the recommendations to include an severe pneumonia. We also recommend that antibiotic eVective against atypical pathogens empirical cover for atypical pathogens should for patients of all ages with severe CAP.5 be oVered to all patients with severe CAP as The frequency of L pneumophilia infection 21% of our patients with atypical infection had was lower than the 15% we reported 17 years features of severe pneumonia and three died. ago, a trend seen in other countries.216 This is also important as several previous stud- Although yearly variation may partly explain ies have found Legionella infection to be the these findings,17 increased use of macrolides in second most common cause of CAP requiring the community may also be relevant.16 Most of intensive care.318 The high proportion of our cases had non-severe CAP, contrary to the patients who died or needed admission to the view that Legionella infection is usually severe.18 intensive care unit within the first few days of All our cases received an early macrolide as hospital admission emphasises the need for part of their hospital treatment, possibly influ- early identification of patients with severe encing our low mortality. Delayed treatment pneumonia. The modified BTS rule performs for Legionella infection relates to increased better than the BTS rule in this regard, with 19 mortality. Furthermore, the report of a sensitivity and NPV values being high, even in positive Legionella urine antigen test within 3 the elderly population. We found that patients days of admission positively influenced early could be stratified into increasing mortality risk management in seven of nine patients, empha- groups using the four individual “core” fea- sising the likely value of urine antigen detection tures of the mBTS rule (CURB: Confusion, as a rapid diagnostic tool for patients admitted Urea, Respiratory rate, Blood pressure)—a to hospital with CAP. strategy which may be more useful in manage- Infection with M pneumoniae was uncom- ment than just two categories of severe and mon which is probably explained by the four non-severe. The “post-take” ward round is yearly cycle of mycoplasma epidemics in recommended as a good time to review Europe; our study coincided with the tail end 3 patients and to decide on step up or step down of a national epidemic. Our mycoplasmal of treatment options. pneumonia rate of 3% is similar to the 2% For non-severe CAP our study supports the reported in 1982, contrasting with the 14% use of empirical antibiotic cover for atypical and 18% rates reported in UK studies during 24 pathogens for younger patients admitted to epidemic years. Ready access to current epi- hospital but not for elderly patients. Atypical demiological trends, as is available on the pathogens were twice as common in younger PHLS website (www.phls.co.uk), could be use- patients and led to no deaths in elderly patients ful to clinicians for planning empirical anti- presenting with features of non-severe pneu- biotic management. monia. Avoidance of early routine combination Most of the cases of influenza were compli- antibiotics, including a macrolide, in this latter cated by bacterial co-infections, emphasising patient group would probably be of net advan- the importance of influenza prevention. Only tage in view of the complications of multiple 68 of 175 eligible patients (39%) had received antibiotic use in the elderly. the influenza vaccine in the preceding 12 Overall, this study supports the current UK months, higher than the estimated 23% vaccine recommendations for covering the range of uptake among high risk patients in England pathogens found in the management of CAP, and Wales in 1996/7 but still an area that can be 20 stratified according to disease severity. Rapid improved. Similarly, pneumococcal vaccina- urine antigen testing looks promising as tion in the last 10 years was reported in only 29 an early way of detecting some pathogens (25%) of 114 eligible patients. including S pneumoniae and L pneumophila. More experience is needed before recom- IMPLICATIONS FOR THE MANAGEMENT OF CAP mending these tests as a reliable way of direct- How does this study contribute to the develop- ing more accurately the initial antibiotic ment of an up to date management strategy for choice for CAP. patients hospitalised with CAP? Nearly all hospitals in the UK now operate an integrated emergency admission policy for We would like to thank Hoechst Marion Roussel for supporting adults of all ages, many of whom are elderly. this study through a research grant and Binax for providing the Streptococcus pneumoniae Binax-NOW antigen detection kits Our patient cohort is typical of the pattern of free. We are grateful to all who contributed in diVerent ways to this study: Robert Cave, Joanne Palfryman and the team of CAP in the UK with half aged 65 years and technical and medical staV at Nottingham Public Health Labo- above and about 40% over 75 years.121We have ratory for their dedication to the study, Anne Jaakkola in Finland who coordinated the microbiology specimens, and phy- shown that penicillin sensitive S pneumoniae sicians at Nottingham City Hospital for allowing us to study remains the most important pathogen in adults their patients.

www.thoraxjnl.com Study of community acquired pneumonia aetiology (SCAPA) in adults admitted to hospital 301

Conflicts of interest: TB has received research funding from 13 Shemer-Avni Y, Lieberman D. Chlamydia pneumoniae- Eisai Ltd and support for attending conferences from Wyeth. induced ciliostasis in ciliated bronchial epithelial cells. J WSL has received research funding from Hoechst Marion Infect Dis 1995;171:1274–8. Roussel (this study) and Bayer and support for attending 14 Kauppinen MT, Saikku P, Kujala P, et al. Clinical picture of conferences from Bayer. JTM has received consultancy fees community-acquired Chlamydia pneumoniae pneumonia from Pfizer, Abbott, Hoechst Marion Roussel, Trinity, Glaxo requiring hospital treatment: a comparison between Wellcome, research funding from Hoechst Marion Roussel (this chlamydial and pneumococcal pneumonia. 1996; study), Rhone Poulenc Rorer and Bayer, lecture fees from Thorax AstraZeneca, Hoechst Marion Roussel and Pfizer and support 51:185–9. for attending conferences from Astra, Pfizer, Allen and Hanbury 15 Troy CJ, Peeling RW, Ellis AG, et al. Chlamydia pneumoniae and 3M. as a new source of infectious outbreaks in nursing homes. JAMA 1997;277:1214–8 (published erratum appears in JAMA 1997;278:118). 1 Guest JF, Morris A. Community acquired pneumonia: the 16 Ruiz M, Ewig S, Torres A, et al. Severe community-acquired annual cost to the National Health Service in the UK. Eur pneumonia. Risk factors and follow-up epidemiology. Am J Respir J 1997;10:1530–4. Respir Crit Care Med 1999;160:923–9. 2 Macfarlane JT, Ward MJ, Finch RG, . Hospital study of et al 17 Woodhead MA, Macfarlane JT, Macrae AD, et al. The rise adult community acquired pneumonia. Lancet 1982; 255–8. and fall of Legionnaires’ disease in Nottingham. J Infect 3 Anonymous. Community-acquired pneumonia in adults in 1986;13:293–6. British hospitals in 1982–1983: a survey of aetiology, mor- 18 Woodhead MA, Macfarlane JT, Rodgers FG, et al. Aetiology tality, prognostic factors and outcome. The British and outcome of severe community-acquired pneumonia. J Thoracic Society and the Public Health Laboratory Infect 1985;10:204–10. Service. QJMed1987;62:195–220. 19 Heath CH, Grove DI, Looke DF. Delay in appropriate 4 White RJ, Blainey AD, Harrison KJ, et al. Causes of therapy of Legionella pneumonia associated with increased pneumonia presenting to a district general hospital. Thorax mortality. Eur J Clin Microbiol Infect Dis 1996;15:286–90. 1981;36:566–70. 20 Irish C, Alli M, Gilham C, et al. Influenza vaccine uptake 5 British Thoracic Society. Guidelines for the management of and distribution in England and Wales, July 1989 to June community-acquired pneumonia in adults admitted to 1997. Health Trends 1998;30:51–5. hospital. Br J Hosp Med 1993;49:346–50. 21 Lim WS, Lewis S, Macfarlane JT. Severity prediction rules 6 Marrie TJ, Blanchard W. A comparison of nursing in community acquired pneumonia: a validation study. home-acquired pneumonia patients with patients with community-acquired pneumonia and nursing home pa- Thorax 2000;55:219–23. tients without pneumonia. J Am Geriatr Soc 1997;45:50–5. 22 Jalonen E, Paton JC, Koskela M, et al. Measurement of anti- 7 Neill AM, Martin IR, Weir R, et al. Community acquired body responses to pneumolysin: a promising method for pneumonia: aetiology and usefulness of severity criteria on the presumptive aetiological diagnosis of pneumococcal admission. Thorax 1996;51:1010–6. pneumonia. J Infect 1989;19:127–34. 8 Lieberman D, SchlaeVer F, Boldur I, et al. Multiple patho- 23 Leinonen M, Syrjala H, Jalonen E, et al. Demonstration of gens in adult patients admitted with community acquired pneumolysin antibodies in circulating immune complexes: pneumonia: a one year prospective study of 346 consecu- a new diagnostic method for pneumococcal pneumonia. tive patients. Thorax 1996;51:179–84. Serodiagn Immunother Infect Dis 1990;4:451–8. 9 SteinhoV D, Lode H, Ruckdeschel G, et al. Chlamydia pneu- 24 Burman LA, Leinonen M, Trollfors B. Use of serology to moniae as a cause of community-acquired pneumonia in diagnose pneumonia caused by nonencapsulated Haemo- hospitalized patients in Berlin. Clin Infect Dis 1996;22:958– philus influenzae and Moraxella catarrhalis. J Infect Dis 1994; 64. 170:220–2. 10 Bartlett JG, Breiman RF, Mandell LA, et al. Community- 25 Dominguez J, Gali N, Matas L, . Evaluation of a rapid acquired pneumonia in adults: guidelines for management. et al immunochromatographic assay for the detection of The Infectious Diseases Society of America. Clin Infect Dis Le- 1998;26:811–38. gionella antigen in urine samples. Eur J Clin Microbiol Infect 11 Kauppinen MT, Herva E, Kujala P, et al. The etiology of Dis 1999;18:896–8. community-acquired pneumonia among hospitalized pa- 26 Helbig JH, Ullman SA, Luck PC, et al. Detection of tients during a Chlamydia pneumoniae epidemic in Finland. Legionella pneumophila antigen in urine samples using the J Infect Dis 1995;172:1330–5. Binax Now immunochromatographic assay and compari- 12 Marrie TJ, Grayston JT, Wang SP, et al. Pneumonia associ- son with both Binax Legionella urinary enzyme immu- ated with the TWAR strain of Chlamydia. Ann Intern Med noassay (EIA) and Biotest Legionella urine antigen EIA. J 1987;106:507–11. Med Microbiol 2001 (in press).

Want full text but don't have a subscription?

Pay per view

For just $8 you can purchase the full text of individual articles using our secure online ordering service. You will have access to the full text of the relevant article for 48 hours during which time you may download and print the pdf file for personal use.