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Biomedical subjects

J T Macfarlane

Publications and source records attributed to J T Macfarlane.

At least 37 records · Page 2Linked to original sources
PubMed1996

Serogroup-specific epidemiology of Streptococcus pneumoniae: associations with age, sex, and geography in 7,000 episodes of invasive disease.

A study sample of 7,010 episodes of invasive Streptococcus pneumoniae disease was obtained by combining 13 existing datasets. Disease episodes due to each of 12 pneumococcal serogroups (1, 3-9, 14, 18, 19, and 23) were then compared with episodes in a constant internal control group to describe serogroup-specific variations in disease frequency by age, sex, and geographic origin. The results are presented as odds ratios (with 95% confidence intervals) derived by logistic regression, with adjustment for the major confounders, including dataset of origin. Variation in the male:female ratios between serogroups is small, suggesting that capsular characteristics are an unlikely explanation for the male preference of S. pneumoniae. Serogroups associated with higher nasopharyngeal prevalence (e.g., 19 and 24) are relatively more common in Europe and North American, while the invasive serotypes 1 and 5 are much more common in South America. The custom of reporting serogroup frequencies in two age groups, children and adults, conceals much of the variation in the age distributions across the whole span of life. The reduction of risk associated with serogroups 6, 14, 18, 19, and 23 beyond childhood follows different gradients, being most abrupt in serogroups 14 and most gradual in serogroup 18. The relative risk of disease with serotype 1 declines steadily throughout life, while with serotypes 3 and 8 it increases over middle age. Serogroups 7 and 23 are found unusually frequently in the third decade of life. Because of the wide differences in the epidemiology of individual serogroups of S. pneumoniae, it is questionable whether pneumococcal infection should continue to be classified as a single disease entity.

Adolescent↗
PubMed1996

Clinical features of patients with beta-lactamase producing Haemophilus influenzae isolated from sputum.

Ampicillin resistance amongst isolates of Haemophilus influenzae is of increasing concern but its clinical impact is unclear. We performed a retrospective study of 34 hospital patients with lower respiratory tract infection (LRTI) caused by beta-lactamase positive (beta+) H. influenzae and compared these with 34 control patients with LRTI caused by beta-lactamase negative (beta-) strains. Chronic obstructive pulmonary disease was the most common underlying condition in both groups (beta+ 23/24, beta- 25/34). A recent course of antibiotics, especially ampicillin/amoxycillin, was significantly (P < 0.05) more common in the beta+ group (beta+ 17/34, beta- 3/34). Other pathogens were isolated more frequently in the beta+ group (beta+ 10/34, beta- 4/34). There was no difference in outcome between the two groups.

Adult↗
PubMed1995

Streptococcus milleri pulmonary disease: a review and clinical description of 25 patients.

BACKGROUND: Streptococcus milleri is increasingly being recognised as an important pulmonary pathogen which may lead to the development of empyema or lung abscess. Although several small series have been reported, the clinical and laboratory features have yet to be fully characterised. METHODS: Twenty five cases were identified and the clinical and laboratory data from case records were analysed. RESULTS: There were 16 empyemas, five lung abscesses, and four with both lung abscess and empyema. The mean age of the patients was 61 years (range 36-89) and 84% were men. The most common symptoms at presentation were shortness of breath, chest pain, cough, and weight loss; only 36% had a fever. Four of the nine patients with lung abscess required a diagnostic lobectomy because of suspected malignancy. Predisposing factors were present in 80% of patients and included the following: pneumonia, periodontal disease, excess alcohol intake, previous thoracic surgical procedures, and malignancy. Laboratory features of S milleri infection were leucocytosis, neutrophilia, anaemia, abnormal liver function tests, and hypoalbuminaemia. In the group with empyema five patients had a pneumothorax on initial presentation and pleural loculation occurred in 10 of these patients. The median stay in hospital was 34 days (range 11-88). Six patients died, five of whom had significant underlying illnesses. CONCLUSIONS: Pulmonary infection with S milleri may result in considerable morbidity and mortality, and is characterised by a strong male predominance, non-specific symptoms (often without toxicity), the presence of predisposing factors, pleural loculation, pneumothorax, and a protracted stay in hospital.

Adult↗
PubMed1994

Audit of pleural biopsies: an argument for a pleural biopsy service.

We audited 203 consecutive pleural biopsies performed by medical and geriatric firms over a 3-yr period in our hospital (1987-9). For firms without a special respiratory interest only two to three biopsies per yr were performed, compared with 23 per yr for a respiratory team. Twenty percent of biopsies failed to obtain pleural tissue, 50% revealed normal or non-diagnostic pleural changes and 30% provided a diagnosis. For the respiratory team that performed a third (68) of the biopsies the failure rate for obtaining pleura was 9% compared with 27% for other teams. In view of this disparity a pleural biopsy service was offered by the respiratory team during routine bronchoscopy lists. A repeat audit (1990-2) following the introduction of this service revealed that 60% (84) of 141 biopsies were performed by the respiratory team with their failure rate for obtaining pleura being lower at 6% as compared to 16% for the general physicians. Thirty-one percent of biopsies provided a definitive diagnosis, being higher for those performed by the respiratory team (37%) as opposed to 23% for general physicians.

Biopsy, Needle↗
PubMed1993

Prospective study of aetiology and outcome of adult lower-respiratory-tract infections in the community.

Community-acquired adult lower-respiratory-tract infections (LRTI) are generally thought to be caused by atypical and viral infections. We have studied 480 adults presenting to a single general practice with community-acquired LRTI between November, 1990, and December, 1991. The overall incidence was 44 cases per 1000 population per year; the incidence was 2-4 times higher in people aged 60 and over than in those aged less than 50. 206 patients were studied in detail; among this group 91 (44%) had 113 pathogens identified. There were 92 bacteria (Streptococcus pneumoniae in 62 and Haemophilus influenzae in 16), 19 viruses (influenza virus in 12), and only 2 atypical pathogens (Mycoplasma pneumoniae and Coxiella burnetii). Pneumococcal infection was common in people who were 60 or older, those who had underlying chronic disease, or people with both features. There was moderate morbidity in terms of time in bed, time to return to normal activities, and days off work. 25% of patients returned for a second consultation with the general practitioner, in most because of unsatisfactory clinical progress. Community-acquired LRTI are very common, and the range of causative pathogens is similar to that for community-acquired pneumonia. Existing management strategies seem inadequate.

Adolescent↗
PubMed1993

Early management of younger adults dying of community acquired pneumonia.

We identified all patients under the age of 65 dying from CAP over a 3-yr-period in hospital in our health district. Most had chronic underlying illnesses. The early management of those who had previously been in good health was studied in greater detail, and was not ideal. Recommendations have been made to try and improve the assessment and treatment of patients with severe community-acquired pneumonia.

Adult↗
PubMed1993

Oropharyngeal production of pneumococcal capsular antigen and the potential for contamination of expectorated sputum samples in pneumococcal pneumonia.

The presence of pneumococcal capsular antigen (PCA) in the oropharynx was sought in subjects without respiratory tract infection. Saliva specimens from 239 subjects were analysed by counter-current immunoelectrophoresis using 'Omniserum'. 15.5% gave positive reactions but only 24% of positive samples were typable and therefore due to pneumococcal or pneumococcal-like antigens. Given that oropharyngeal production of antigens occurs we investigated whether PCA in expectorated sputum arose from oropharyngeal contamination. Sixteen patients with pneumococcal pneumonia, and with sputum positive for PCA, were investigated in detail. On the basis of serotyping and concentration the PCA in sputum was thought to arise from the lower respiratory tract in all cases. This was confirmed by a simple, novel approach involving the comparison of concentrations in concomitant samples of saliva and sputum. Thus while oropharyngeal production of antigens poses a potential diagnostic problem the latter approach can be used to exclude contamination.

Adolescent↗
PubMed1990

Nosocomial lower respiratory tract infections in surgical wards.

A six month prospective study of nosocomial lower respiratory tract infection was conducted in four general surgery wards and one urological surgery ward. Thirty eight cases were identified, representing 1% of the surgical admissions to these wards. Twenty eight of the infections followed abdominal surgery. Six patients died, five of whom had pre-existing cardiorespiratory disease. Potential pathogens were isolated in 21 patients, the commonest organisms being Streptococcus pneumoniae and Haemophilus influenzae.

Adult↗
PubMed1990

A hospital study of community acquired pneumonia in the elderly.

Studies on community acquired pneumonia in the United States in patients over the age of 65 years have shown that Gram negative bacilli account for an appreciable proportion of cases, in addition to usual pathogens such as Streptococcus pneumoniae and Haemophilus influenzae. There have been no reports of community acquired pneumonia in the elderly in the United Kingdom. We undertook such a study to determine the clinical features, aetiology, and outcome. Seventy three patients (38 men) with ages ranging from 65 to 97 (median 79) years were studied prospectively. Pneumonia was defined as an acute lower respiratory tract infection with new, previously unrecorded shadowing on a chest radiograph. Patients with severe chronic illness in whom pneumonia was an expected terminal event were excluded. Nearly all the patients (96%) had respiratory symptoms or signs but many had features that might obscure the true diagnosis of pneumonia. Over half the patients had non-respiratory symptoms and over a third had no systemic signs of infection. A pathogen was identified in 43% of patients, most commonly Streptococcus pneumoniae, Haemophilus influenzae and influenza B virus. Gram negative bacilli were not seen. The mortality rate was high (33%). Early deaths were due to infection whereas later deaths were associated with other factors, such as stroke (two patients) and pulmonary embolism (two patients). Prognostic indicators for mortality were apyrexia, systolic hypotension, increasing hypoxaemia, and new urinary incontinence. As the range of pathogens causing pneumonia was the same in the elderly in this study as in other age groups it is suggested that initial antibiotic treatment for patients in this age group should always cover S pneumoniae and H influenzae.

Aged↗
PubMed1990

Current concepts in the management of sarcoidosis.

Sarcoidosis can affect almost every organ. It has diverse clinical presentations and a variable natural history. Lungs and intrathoracic lymph nodes are the most commonly involved tissues. A major challenge to clinicians is the early identification of those patients with aggressive disease in whom therapy might arrest progression. Although lung uptake of 67Ga citrate, elevated serum angiotensin converting enzyme (ACE) levels and elevated T lymphocyte count in bronchoalveolar lavage fluid are all thought to reflect disease activity, they are by no means reliable markers. Because recent studies have shown that corticosteroid treatment does not avert pulmonary fibrosis and permanent impairment of pulmonary function, the use of these agents is restricted to the palliative treatment of disabling symptoms and physiological derangements. Corticosteroids are effective in reducing ocular inflammation, correcting hypercalcaemia, improving pulmonary function and alleviating symptoms related to hepatic, splenic, articular, myocardial, neural and cutaneous involvement. In the small proportion of patients who do not respond to moderate tolerable doses of steroids, alternative drug therapy such as immunosuppressives or immune modulators must be considered.

Adrenal Cortex Hormones↗
PubMed1987

Prospective study of the aetiology and outcome of pneumonia in the community.

A prospective one-year study of community pneumonia was conducted in Nottingham. 236 of 251 episodes of pneumonia (defined as an acute lower respiratory tract infection, for which antibiotics were prescribed, associated with new focal signs on examination of the chest) were investigated. Acute radiographic changes were present in 93 (39%). A pathogen was identified in 129 (55%) episodes, with Streptococcus pneumoniae, Haemophilus influenzae, and influenza viruses those most frequently identified. Mycoplasma pneumoniae was uncommon and infection with Legionella pneumophila was found in only 1 episode. Hospital admission was required in 52 (22%) episodes. 7 patients died (3%), all but one of the deaths occurring in patients who had been admitted to hospital. Pneumonia in the community is common but few people die of it. Initial antibiotic therapy should always cover S pneumoniae and H influenzae.

Acute Disease↗
PubMed1987

Comparative clinical and laboratory features of legionella with pneumococcal and mycoplasma pneumonias.

The clinical and laboratory features of 83 cases of community-acquired pneumococcal pneumonia (PP), 79 cases of legionella pneumonia (LP) and 62 cases of mycoplasma pneumonia (MP) have been compared. No unique features have been found in any group. Patients with MP were younger, were more likely to have had prior antibiotics before hospital referral, had a predominance of upper respiratory tract symptoms, low total white cell counts and lacked features of multisystem involvement. Multisystem features were common in both PP and LP with confusion, high fever, hyponatraemia, hypoalbuminaemia and abnormalities of liver function occurring more often in LP. A high leucocyte count was especially common in PP. Antibiotic therapy in community-acquired pneumonia must remain empirical until a definite microbiological diagnosis is made.

Adolescent↗
PubMed1987

Adult community-acquired staphylococcal pneumonia in the antibiotic era: a review of 61 cases.

We have reviewed the clinical and laboratory features of 61 cases of adult community-acquired staphylococcal pneumonia. A seasonal incidence was found and most cases occurred in April. Clinical and laboratory features were similar to those found in other forms of community-acquired pneumonia. Sputum Gram-stain was positive for staphylococci in 69 per cent of cases and blood cultures were positive in 20 per cent. Evidence of Influenza virus infection was found in 52 per cent of cases. Eighteen patients died (30 per cent). Age greater than 45 years, confusion, reduced conscious level, raised blood urea, acidosis, bacteraemia and admission to the intensive care unit were associated significantly with death. Despite appropriate antibiotic treatment mortality in staphylococcal pneumonia remains high.

Adolescent↗