rates over many years need to be utilised to determine baseline as well as excess mortality levels. In our study 'Atypical' are a mortality figures on their own over the past few years contributed little to our knowledge of the extent of influenza. common cause of An epidemic of influenza is diagnosed on both virological criteria (the proof of the presence of influenza virus) together community-acquired with epidemiological criteria (based on the presence of these nonspecific indicators). A number of definitions of an in hospitalised epidemic or an epidemic threshold have been devised. For example, the rise of the monthly incidence of influenza-like adults illness beyond 400 per 100 000 inhabitants'6 or the isolation G. Maartens, S. J. Lewis, C. de Goveia, C. Bartie, • of influenza from at least 10% of submitted samples,7 or an excess of cases of influenza-like illness and nonspecific D. Roditi, K. P. Klugman acute respiratory illness for 2 consecutive weeks above the epidemic threshold" Objectives. To assess the proportion of cases of community· The success of the influenza surveillance programme acquired pneumonia caused by 'atypical' bacteria, inclUding depends directly on the interest and enthusiasm of the the recently discovered Chlamydia pneumoniae, and to sentinel doctors and the programme is an example par compare the clinical, radiographic and laboratory features of excellence of how primary care physicians and biomedical patients with and without 'atypical' bacteria. laboratories can co-operate and collaborate in a particularly Methods. A prospective serological study was carried out important preventive medical venture. on consecutive adult pneumonia patients from July 1987 to July 1988. Acute and convalescent sera were tested in Our sincere thanks to all the sentinel doctors who assisted batches for antibodies against Legionella pneumophila so enthusiastically with the Witwatersrand Viral Watch serogroup 1, C. pneumoniae, Chlamydia psittaci, Coxiella Surveillance Programme, as well as the principals and burnetii (phase-2 antigen) and Mycoplasma pneumoniae secretaries of all the schools included in the absenteeism (lgG and IgM). Records and chest radiographs were surveillance programme. We would also like to thank Ms examined retrospectively. Magda de Beer of the Department of Health, Housing and Results. Acute and convalescent sera were available from Urbanisation of the City of Johannesburg, and Or J. Lundie 113 patients. The records of 4 patients could not be traced and Sr E. Joss for providing mortality data for the two and 17 patients did not fulfil the inclusion criteria. Thirty-two homes for the aged studied. of these 92 patients (35,9%) were found to be infected with

REFERENCES 'atypical' bacteria. The two most common organisms were

1. Hayle F. \'Yickramasinghe C. The case for life as a cosmic phenomenon. Nature C. pneumoniae (20,7%) and L. pneumophila (8,7%). There. 1986; 322; 509-511. were no differences in the clinical and radiographic features 2. Douglas R. Prevention, management and control of Influenza: a mandate for the 1980s. Am J Med 1987; 82: 1-3. of patients with and without 'atypical' bacteria. Clinicians 3. Ghendon Y. Influenza surveillance. Bull World j-Iealth Organ 1991; 69: 509-515. prescribed erythromycin or tetracyclines with equal 4. Schoub BD, Johnson S, McAnerney JM, Martin E, Dos Santos IL. Laboratory studies of the 1984 influenza epidemic on the Witwatersrand. S Atr Med J 1986; frequency in the two groups. 70: 815-818. Conclusions. 'Atypical' bacteria, especially C. 5. Assaad F, Cockburn WC, Sundaresan TK. Use of excess mortality from respiratory diseases in the study of influenza. Bull World Health Organ 1973; 49: 219-233. pneumoniae, are a common cause of community-acquired 6. Paul Glezen W, Decker M, Joseph SW, Mercready RG jun. Acute respiratory disease associated with influenza epidemics in Houston, 1981-1983. J Infect Dis pneumonia in adults in South Africa. This is the first 1987; 155: 1119-1126. demonstration of an aetiological role of C. pneumon.iae in 7. Hannoun C, Dab W, Cohen JM. A new influenza surveillance system in France: the lIe-de-France 'GAOG'. 1. Principles and methodology. Eur J Epidemio/1989; 5: this country. We confirmed the finding of other studies that 285-293. there are no clinical, radiographic or laboratory features 8. Public Health Laboratory Service Standing Advisory Committee on Influenza. Influenza surveillance. 1972-1975. J Hyg 1977; 78: 223-233. characteristic of 'atypical' bacterial infection in hospitalised 9. Snacken A, lion J. Van Casteren V, et al. Five years of sentinel surveillance of patients. This has major implications for therapy, as these acute respiratory infections (1985-1990). The benefits of an influenza eany warning system. Eur J Epidemiol 1992; 8: 485-490. organisms respond to erythromycin and tetracyclines, but· 10. Wand Health Organisation. Report of WHO/GEIG informal consultation on the ~-Iactam standardisation and improvement of Influenza surveillance, Monaco, 25 September not to antibiotics. 1991 (WHO/GEIG.RPT/ke/5). Geneva: WHO. 1991; 1-5. S Afr Med J 1994; 84: 678-682. 11. Mancini GM, Arangio-Ruiz G. Campitelli L. et al. Surveillance of influenza A and 8 viruses in Italy between 1984 and 1987. Eur J Epidemiol 1988; 4: 445-450. 12. World Health Organisation. Aecommended composition of Influenza virus vaccines for use in the 1990-1991 season. WkJy Epidemiol Aec 1990; 65: 53-60. 13. Wand Health Organisation. Recommended composition of Influenza virus vaccines for use in the 1991-1992 season. WkJy Epidemiol Rec 1991; 66: 57-64. Departments of Medicine and Medical Microbiology, Groote Schuur 14. World Health Organisation. Recommended composition of Influenza virus vaccines Hospital and University of Cape Town for use in the 1992-1993 season. WkJy Epidemiol Rec 1992; 67: 57-64. 15. Udwell OM. Sommerville T. Observations on the incidence and distribution of the G. Maartens. EC.P. (SA) common cold in a rural community during 1948 and 1949. J Hyg 1951; 49: 365­ 381. S. J. Lewis. M.RC.? (UX) 16. Fleming DM, Ayres JG. Diagnosis and patterns of Incidence of influenza-like illness C. de Goveia. M.MED. (MICROBIOL) and the common cold in general practice. J R CoJJ Gen Pract 1988; 38: 159-162. D. Roditi. M.MED. (MICROBIOL) Accepted 4 July 1994. Department of Microbiology, South African Institute for Medical Research and University of the Witwatersrand, Johannesburg

C. Bartie. 8.SC. HONS

K. P. KJugman. PH.D.• EE PATH. (SA)

Volume 84 No. 10 October 1994 SAMJ SAMJ

ARTICLES

Atypical pneumonia is a clinical syndrome first described by All of the studies quoted so far were performed in Reimann in 1938.' There is no precise definition of this developed countries. A previous study from this institution22 syndrome! but the illness has a subacute onset with showed that 10% of cases were due to M. pneumoniae. constitutional symptoms and a dry cough. Radiographic Other 'atypical' bacteria were not tested for in that study. shadowing is characteristically non-segmental and more The aim of the current study was to assess the proportion of extensive than the physical examination would suggest. cases of community-acquired pneumonia due to M. Leukocytosis is absent or moderate. The course is generally pneumoniae, Legionella pneumophila, C. psittaci, C. benign. Mycoplasma pneumoniae is the most common pneumoniae and C. burnetii in a developing country. A aetiological agent of . Other bacteria that secondary objective was to compare the clinical, cause atypical pneumonia are Chlamydia psittaci, Legionella radiographic and laboratory features of patients with and spp. and Coxiella burnetii (the agent that causes Q fever)! without 'atypical' bacteria. These organisms share three characteristics: they are not visible on , they do not grow on conventional culture media and they do not respond to or . Patients and methods There is a widespread belief that pneumonia caused by We evaluated consecutive adults with an admission these organisms can readily be differentiated from diagnosis of pneumonia from July 1987 to July 1988 at pneumonia due to conventional bacteria. However, the most Groote Schuur Hospital, a large community-based university common radiographic finding in pneumonia due to these hospital. Pneumonia was defined as an acute respiratory four 'atypical' bacteria is unilateral consolidation, often lobar illness with compatible shadowing on chest radiograph or segmental,3-8 and the clinical features are generally (performed on admission or within 48 hours). Patients with indistinguishable from those found in pneumonia caused by pulmonary tuberculosis or severe immunosuppression (e.g. conventional bacteria. 2.7,'0 in cases of AIDS) were excluded. Folders were Table I summarises four recent studies which show that retrospectively reviewed for demographic data, underlying 'atypical' bacteria cause a significant proportion of cases of illnesses, symptom duration, blood pressure values, community-acquired pneumonia in adults. The major respiratory rate, presence of confusion, laboratory features differences in these studies are the incidence of (P02, urea values, white cell count) and whether the chest mycoplasma pneumonia, which occurs in cyclical epidemics radiograph showed a segmental or non-segmental pattern every few years," and legionella pneumonia which varies of pulmonary shadowing. geographically and temporally." A fifth 'atypical' bacterium that causes pneumonia has Microbiological methods recently been discovered. Chlamydia pneumoniae (formerly known as Chlamydia strain TWAR) was found to be Acute and convalescent (2 - 4 weeks) sera were collected. The study was originally set up to assess the incidence of responsible for 12% of cases of mild pneumonia in college L. pneumophila. Paired sera were tested simultaneously for students." Studies of hospitalised patients with community­ L. pneumophila serogroup 1 by an indirect fluorescent acquired pneumonia showed that C. pneumoniae caused .antibody test (IFAT) method using antigen prepared in our 6 - 10% of cases. '.·20 It was also shown that there were no laboratory. Positive results were checked with control differences in clinical or radiographic features of patients antigen from the Centers for Disease Control (COG), Atlanta with pneumonia caused by C. pneumoniae and those in lJSA. The sera were then frozen at -20°C and SUbsequently whom other pathogens were responsible. '8-20 A chlamydia tested in batches (avoiding multiple freeze-thaw) for IgM and complement fixation test is Widely used to diagnose IgG antibodies against M. pneumoniae (IFAT, Diagnostic and psittacosis. This test is not species-specific and can be Technical Services), Q fever phase·2 antigen (I FAT, bio­ positive in primary infections (but not re-infections) with Merieux), C. psittaci (IFAT, bio-Merieux), and C. pneumoniae C. pneumoniae.21 It is therefore likely that some cases of (IFAT, antigen supplied by professor C. C. Kuo, Washington psittacosis found in earlier pneumonia studies were in fact UniverSity, USA). Definite infections were indicated by a causeo' ~"::. oneumoniae. Even so, roughly 20 - 40% of ~ith ~ommuniiy-;:;~~uired pn~umonia 4-fold rise in titre or a titre of > 16 for M. pneumoniae IgM. patients will have Probable infections were diagnosed when a single titre was infections caused by 'atypical' bacter'i';. To date there IS no ~ 64 for mycoplasma IgG, ~ 256 for C. psittaci, Q fever and 2 commercially available test to detect C. pneumoniae L. pneumophila, and ~ 512 for C. pneumoniae. ' antibodies; this has hindered the investigation of the Results of sputum and blood cultures were recorded if the aetiological role of this agent in community-acquired clinicians looking after the patient had requested these pneumonia. tests.

Table I. Proportion of community-acquired pneumonia cases caused by 'atypical' bacteria in studies of hospitalised adults . . Legionella spp. M. pneumoniae Q fever C. psittaci Country No. of patients No. % No. % No. % No. % 'Atypical' bacteria (%)

UK" 127 19 15 3 2 1 < 1 7 6 24 UK" 453 9 2 81 18 5 1 13 3 24 5;::'t!in 15 462 64 14 16 3 3 < 1 1 < 1 18 15 Australia''; 106 3 3 8 8 0 5 5

SAMJ Volllme 84 o. 10 October 1994 __ Statistical methods The seasonal distribution of pneumonia cases is shown in Fig. 1. Underlying medical conditions were present in 37 Clinical, laboratory and radiographic features of patients patients (Table Ill). with and without 'atypical' bacteria were compared. The x'-test was used to analyse the categoric variables, while 50 r------, Student's Hest (two-tailed) was used to analyse the continuous variables. 40

30 Results 20 . One hundred and seventy-three patients with an admission diagnosis of pneumonia were entered in the study, but convalescent serum was not obtained from 60 of these. The records of the remaining 113 patients were reviewed. The o records of 4 patients could not be traced and 17 patients SUMMER AUTUMN WINTER SPRING did not fulfil the entry criteria for the study. This left 92 DecFeb March-May June-Aug SeprNov patients, 8 of whom were white, 23 black and 61 coloured. • C. pneumoniae o Other 'atypical' bacteria We personally reviewed the radiographs of 72 patients. Our reports correlated very closely with those of the o No evidence of 'atypical' bacteria radiologists which were relied upon for the remaining 20 patients whose radiographs had been destroyed. Fig. 1. Seasonal distribution of pneumonia cases. The results of the serological tests are shown in Table 11. The patient with a 4-fold rise in titre to both C. pneumoniae Table Ill. Underlying conditions in patients with community­ and C. psittaci presumably represents a cross-reaction. Five acquired pneumonia of the patients with serological evidence of 'atypical' bacterial COPD/asthma 13 infection also had sputum cultures positive for conventional Alcoholism 8 bacterial pathogens (3 Haemophilus influenzae, 2 Cardiac failure 6 Streptococcus pneumoniae). In the patients without Diabetes mellitus 4 serological evidence of 'atypical' bacteria there were 5 Bronchiectasis 2 positive blood cultures (4 S. pneumoniae and 1 Pseudomonas Miscellaneous' 4 aeruginosa) and sputum cultures were positive in an additional COPD =chronic obstructive pulmonary disease. .. Chronic renal failure, myasthenia gravis, chronic lymphocytic leukaemia, stroke. 9 (3 H. influenzae, 2 S. pneumoniae, 3 both S. pneumoniae and H. influenzae; and 1 Staphylococcus aureus). There were no differences in the demographic, clinical and Table 11. Patients with positive serological findings for 'atypical' radiographic features of patients with and without bacteria pneumonia due to 'atypical' bacteria (Table IV). The only Organism Definite/probable ("le) laboratory feature that was significantly different between L. pneumophila 8/0 (8,7) the two groups was the urea level, which was higher in the M. pneumoniae 1/0 (1,1) group without 'atypical' bacteria. C. psittaci 2/3 (5,4) The ability of the attending clinicians to distinguish C. burnetii 0/0 (0) presence or absence of 'atypical' bacteria was assessed on C. pneumoniae 19/0 (20,7) the basis of the prescription of erythromycin or tetracycline. Total 32' (35,9) These antibiotics were prescribed for 6 of the 32 (19%) 'One patient had a 4·101d rise in titre to both C. pneumoniae and C. psittaci. patients with 'atypical' bacterial infections versus 12 of the

Table IV. Clinical, radiographic and laboratory features of patients with and without evidence of infection with 'atypical' bacteria Atypical bacteria Absent Present P-value No. 60 32 Sex (M/F) 38/22 14/18 0,11 Mean age (yrs) 41,8 46,5 0,23 Underlying condition present 23 (N = 60) 14(N=31) 0,69 Mean duration of symptoms (days) 5,7 4,9 0,57 Presence of confusion 8 (N= 60) 2(N=31) 0,52 Mean blood pressure 124/74 (N= 59) 127/77 (N= 30) 0,56/0,33 Mean respiratory rate 28,4 (N=21) 26,6 (N =9) 0,62 Mean Pili (kPa) 9,3 (N= 22) 10,0 (N= 11) 0,66 Mean serum urea level (~mol/I) 8,2 (N= 45) 4,2 (N= 20) 0,01 Mean white cell count (10'/1) 13,3 (N= 31) 12,1 (N=16) 0,06 Radiograph type Segmental 38 19 Non-segmental 22 13 0,88 Length of admission (days) 5,2 4,6 0,61

Volume 84 No. 10 October 1994 SAMJ , SAMJ

ARTICLES

60 (20%) without 'atypical' bacteria. According to the fact that most of our patients recovered without specific records, they were prescribed because 'atypical' pneumonia therapy. However, recovery can be prolonged, and was suspected and not because of allergy. Four appropriate therapy considerably shortens the course of the patients, 2 from each group, required admission to an illness.' Apart from legionella pneumonia, mortality from intensive care unit, and both patients from the 'atypical' pneumonia caused by other 'atypical' bacteria is generally group had L. pneumophila pneumonia. low··'·9.20." However, some studies have found that the Clinical, demographic and radiographic features of mortality rate of pneumonia caused by M. pneumoniae'4 or patients with C. pneumoniae pneumonia did not differ C. pneumoniae,6.,9 is similar to that of pneumococcal significantly from patients with other 'atypical' bacteria or pneumonia. from the group without 'atypical' bacteria. Appropriate therapy for pneumonia caused by 'atypical' bacteria is erythromycin or tetracyclines. Doxycycline is probably the tetracycline of choice in this situation as it can be taken twice daily and has better intracellular penetration Discussion (all of these agents except M. pneumoniae are intracellular). We have shown that 'atypical' bacteria cause more than Erythromycin and tetracyclines are equally effecti\{e in M. one-third of cases of community-acquired pneumonia in pneumoniae infections! but the tetracyclines seem to be 2 2 adults. C. pneumoniae was responsible for 20,7% of more active against chlamydia . ' Erythromycin is generally pneumonia cases. This is higher than has been reported in regarded as the agent of choice for legionella pneumonia, 2 27 other serological surveys,17'20 but a similar proportion was but tetracyclines are also effective . There are very few found in a study using culture and serology!3 C. pneumoniae controlled trials comparing these two agents in pneumonia occurs in cyclical 4 - 6-year epidemics21 and our study was caused by 'atypical' bacteria. A recent study has shown that presumably conducted during an epidemic year. The doxycycline is more active than erythromycin in cases of Q proportion of cases of legionella pneumonia (8,7%) in this fever!' study is intermediate between areas with a low,.·,6 and a The specific aetiological agent should be sought in high"·15 incidence. Our fin.ding is an underestimate, as we hospitalised adults with community-acquired pneumonia did not test for other L. pneumophila serogroups or other in order to direct antibiotic therapy. An urgent Gram stain LegioneJla spp., which collectively account for about half of of an adequate sputum sample has proved a useful legionella pneumonia cases!4 There was no evidence of a investigation!022 Tuberculosis can manifest itself as an legionella outbreak, as the patients came from different acute pneumonia in our area!2 and a Ziehl-Neelsen stain geographical areas at separate times. should be requested if the Gram stain is negative. If no . The only significant difference between patients with and organism is identified, empirical therapy for patients with without 'atypical' bacteria was in the serum urea level, which mild-to-moderate pneumonia should cover S. pneumoniae, was lower in patients with 'atypical' bacteria. An elevated which is the most common cause,'3.15.20Z1 or H. influenzae if urea level has been shown to be a poor prognostic factor in chronic obstructive pulmonary disease is present. Therapy pneumonia,'4 and is unlikely to help in the identification of directed against 'atypical' bacteria can be added initially or if specific pathogens. In the current study, erythromycin or .response is delayed or incomplete. Patients with pneumonia tetracyclines were prescribed with the same frequency in caused by 'atypical' bacteria may respond to ~-Iactam patients with and without 'atypical' bacteria; this further antibiotics if secondary bacterial infection is present; this emphasises that the two groups are indistinguishable. occurred in 5 of our patients and was a frequent finding in Antibiotics directed against the enterobacteriaceae were other studies.,4.'6Z1 prescribed more frequently, despite the fact that these In severe community-acquired pneumonia there is an organisms do not usually cause community-acquired increased incidence of LegioneJla spp., S. aureus and the pneumonia.'3.,6.20Z1 enterobacteriaceae, although S. pneumoniae remains the In a recent large prospective study, Fang et al!° found no most common aetiological organism!9.3' The mortality rate in characteristic features in hospitalised patients with this context is very high and some have argued that an early 30 pneumonia due to 'atypical' bacteria and concluded that invasive procedure to establish aetiology is justified. If no the term 'atypical pneumonia' should be abandoned. Yung organism is identified, then empirical therapy should cover et a/! commented that the term 'is only of value in the age enterobacteriaceae and S. pneumoniae. Specific group of 10 - 60 years, in previously healthy patients, in antistaphylococcal therapy should be added in an influenza those with community-acquired disease and those without a epidemic, or if clinically indicated. The decision to add life-threatening illness'. intravenous erythromycin (which is very expensive) should The majority of infections with 'atypical' bacteria are depend on the local incidence of legionella pneumonia. A . subclinical, and only a small minority of patients require retrospective study from this institution found that legionella hospitalisation for pneumonia. An atypical presentation may pneumonia accounted for 5 of 95 patients with community­ be associated more strongly with 'atypical' bacteria in mild acquired pneumonia requiring ICU admission.31 However, pneumonia not requiring admission. However, this has not serological tests were only performed in 40 patients and been addressed in a prospective study. Such a study would were directed only at L. pneumophila. Mortality from severe be difficult to perform as atypical pneumonia is ill-defined, legionella pneumonia is considerably increased in patients and previous attempts at a definition have focused on not receiving appropriate therapy! characteristics of 'atypical' bacteria."·26 The current study has several weaknesses. Firstly, the Patients with pneumonia caused by 'atypical' bacteria clinical, radiographic and laboratory data were gathered generally make a spontaneous recovery as illustrated by the retrospectively. Secondly, no special attempts were made to

SAMJ VO/l/lI/e84 No. 10 October /994 ~ identify conventional bacteria or viruses. Thirdly, more cases of mild-to-moderate pneumonia were studied as The usefulness of convalescent serum was an entry requirement; this resulted in the exclusion of those who died from severe pneumonia. cerebrospinal fluid tests for Nevertheless, our conclusion that 'atypical' bacteria are a major cause of community-acquired pneumonia in our area neurosyphilis remains valid. This has major implications for therapy. H. G. Russouw, M. C. Roberts, R. A. Emsley, This study was supported by the UCT Research Fund. J.J.Joubert Etienne Theron's technological input was invaluable.

To determine the usefulness of cerebrospinal fluid (CSF) REFERENCES tests for syphilis at a large academic hospital, clinical and 1. Reimann HA. An acute infection of the respiratory tract with atypical pneumonia. JAMA 1938; 111: 2377-2384. laboratory data on 644 patients in whom such testing was 2. Yung AP. Newton-John HF, Stanley PA. Atypical pneumonia: recognition and treatment. Med J Aust 1987; 147: 132-136. requested over a 12-month period were analysed. In 198 3. Finnegan QC, Fowles SJ. White RJ. Radiographic appearances of mycoplasma cases (31 %) the Treponema paJlidum haemagglutination pneumonia. Thorax 1981: 36: 469-472. 4. Yung AP, Grayson ML. Psittacosis - a review of 135 cases. Med J Aust 19S8; (TPHA) screening test could not be performed bec~use of 148: 228-233. 5. Smith Dl, Wellings A, Walker C, Ayres JG, Surge PS. The chest x-ray in Q-fever: a insufficient fluid. Thirty-eight of the remaining pati.ents report on 69 cases from the 1989 West Midlands outbreak. Br J Radiol 1991; 64: 1101-1108. were diagnosed as having active neurosyphilis. 6. Macfarlane JT. Miller AG. Roderick Smith WH, Morris AH, Rose DH. Comparative radiographic features of community acquired legionnaire's disease, pneumococcal Examination of 22 files of patients who had a positive pneumonia, mycoplasma pneumonia, and psittacosis. Thorax 1984; 39: 28-33. 7. Helms CM, Viner JP, Sturm RH, Renner EO, Johnson W. Comparative features of TPHA and fluorescent treponemal antibody absorption pneumococcal, mycoplasma and legionnaire's disease . Ann Intern Med 1979; 90: 543-547. (FTA-Abs) test together with a negative CSF Venereal 8. Ali NJ, Sillis M. Andrews BE, Jenkins PF, Harrison 80. The clinical spectrum and Disease Research Laboratory (VDRL) test revealed that diagnosis of Mycoplasma pneumoniae infection. Q J Med 1986; 58: 241-251. 9. Woodhead MA, Macfarlane JT. Comparative clinical and laboratory features of other CSF measures indicating disease activity (CSF legionella with pneumococcal and mycoplasma pneumonia. Br J Dis Chest 1987; 81: 133-139. protein, cells or IgG index) were not utilised optimally. 10. Yu VL, Kroboth FJ, Shonnard J, Brown A, McOearman S, Magnussen M. Legionnaire's disease: new clinical perspective from a prospective pneumonia In 10 (45%) of these patients neurosyphilis was not study. Am J Med 1982; 73: 357-361. 11. Noah NO, Urquhart AM. Epidemiology of Mycoplasma pneumoniae infection in the diagnosed despite either abnormal or incomplete CSF British Isles. 1974-9. J Infect 1980; 2: 191-194. 12. Woodhead MA, Macfarlane JT, Macrae AD, Pugh SF. The rise and fall of biochemical analysis, indicating that if the CSF VDRL is legionnaire's disease in Nottingham. Jlnfect 1986; 13: 293-296. 13. Macfarlane JT, Finch RG, Ward MJ. Macrae AD. Hospital study of adult used as the sole marker for disease activity, some cases community-acquired pneumonia. Lancet 1982; 2: 255-258. of neurosyphilis are likely to be missed. 14. British Thoracic Society. Community-acquired pneumonia in adults in British hospitals in 1982-1983: a survey of aetiology. mortality, prognostic factors and S Afr Med J 1994; 84: 682-684. outcome. Q J Med 1987; 62: 195-220. i 5. Blanquer J. Blanquer R. Borras R. et al. Aetiology of community acquired pneumonia in Valencia, Spain: a multicentre prospective study. Thorax 1991; 46: 508-511. 16. Urn I, Shaw OR. Stanley DP, Lumb R, McLennan G. A prospective hospital study Notwithstanding the fact that neurosyphilis remains an of the aetiology of community-acquired pneumonia. Med J Aust 1989; 157: 87-91. 17. Grayston JT, Kuo CC, Wang SP, Altman J. A new Chlamydia psittaci strain called important cause of psychiatric morbidity, particularly in TWAR from acute respiratory tract infections. N Engl J Med 1986; 315: 161-168. developing countries such as South Africa,' uncertainty still 18. Marrie TJ. Grayston JT. Wang SP, Kuo CC. Pneumonia associated with the TWAR strain of Chlamydia. Ann Intern Med 1987; 106: 507-511. exists about the application and interpretation of 19. Grayston JT, oiwan VK, Cooney M, Wang SP. Community and hospital acquired pneumonia associated with Chlamydia TWAR infection demonstrated serologically. cerebrospinal fluid (CSF) tests for syphilis!·' This applies Arch Intern Med 1989; 149: 169-173. particularly to patients whose clinical picture is not clear cut 20. Fang GO, Fine M. Orloff J, et al. New and emerging etiologies for community­ acquired pneumonia with implications for therapy. A prospective multicentre study when the CSF Treponema pallidum haemagglutination ot 359 cases. Medicine 1990; 69: 307-316. 21. Grayston JT, Thom OH. The chlamydial pneumonias. In: Remington JS, Swartz (fPHA) or fluorescent treponemal antibody absorption (FTA­ MN. eds. Current Clinical Topics in Infectious Diseases. Vol. 11. Boston: Abs) tests are positive in the presence of a negative CSF Blackwell, 1991: 1-18. 22. Prout S, Potgieter PO, Forder AA, Moodie JW, Matthews J. Acute community­ Venereal Disease Research Laboratory (VDRL) test. acquired pneumonias. S Afr Med J 1983; 64: 443-446. 23. Chirgwin K, Roblin PM, Gelling M. Hammerschlag MA, Schachter J. Infection with The CSF VDRL test is generally regarded as the best Chlamydia pneumoniae in Brooklyn. J Infect Dis 1991; 163: 757-761. available test for active neurosyphilis, despite its low 24. Aeingold AL. Thompson BM. Brake BJ. Thacker L, Wilkinson HW. Kunifsky IN. Legionella pneumonia in the United States: the distribution of serogroups and sensitivity, which can result in some false negative results. species causing human illness. J Infect Dis 1984; 149: 819. 25. Cunha BA, Quintiliani R. The atypical pneumonias: a diagnostic and therapeutic This sensitivity ranges between 10% and 89%, and is approach. Postgrad Med 1979; 66: 95-102. lowest in asymptomatic neurosyphilis and tabes dorsalis.3 26. Marrie TJ. Haldane EV. Noble MA. Faulkner RS, Martin RS. Lee SH. Causes of atypical pneumonia: results of a 1 year prospective study. Can Med Assoc J 1981; The TPHA and FTA-Abs tests are more sensitive and are 125: 1118-1123. valuable as routine screening tests, but both remain positive 27. Cotton EM. Stampfer MJ. Cunha BA. Legionella and mycoplasma pneumonia - a community hospital experience with atypical pneumonias. Clin Chest Med 1987; a for an indefinite period after successful treatment: which (3); 441-453. 28. Sobradillo V, Zalacain R, Capelastegui A, Uresandi F, Corral J. Antibiotic treatment in pneumonia due to Q fever. Thorax 1992; 47: 276-278. 29. Woodhead MA, Macfarlane JT, Aodgers FG, Laverick A, Pilkington R, Macrae AD. Aetiology and outcome of severe community-acquired pneumonia. J Infect 1985; 10: 204-210. Departments of Psychiatry and Microbiology, University of 30. Pachon J, Prados MO. Capote F, Cuello JA. Garnacho J. Verano A. Severe community-acquired pneumonia. Etiology, prognosis and treatment. Am Rev Stellenbosch, Tygerberg, W. Cape Respir Dis 1990; 142: 369-373. H. G. Russouw, M.8. CH.B.• M.MEO. (PSYCH.) 31. Potgieter PO, Hammond JM. Etiology and diagnosis of pneumonia reqUiring ICU admission. Chest 1992; 101: 199-203. M. C. Roberts. M.B. CH.B.• B.SC. HONS (EPIDEMIOL.)

Accepted 17 Feb 1994. R. A. Emsley. M.B. CH.B.• M.MEO. (PSYCH.)

J. J. Joubert. M.B. CH.B.• M.D.

~ Volume 84 No. 10 October 1994 SAMJ