The observational data presented by Macfarlane et al on the aetiology of
acute lower respiratory tract illness in the community[1] confirm that the
often stated assertion that these illnesses are usually caused by viral
infection is incorrect. The high prevalence of bacteriological and
atypical pathogens, and in particular the high prevalence of C pneumoniae
in these patients is of interest and points to the n...
The observational data presented by Macfarlane et al on the aetiology of
acute lower respiratory tract illness in the community[1] confirm that the
often stated assertion that these illnesses are usually caused by viral
infection is incorrect. The high prevalence of bacteriological and
atypical pathogens, and in particular the high prevalence of C pneumoniae
in these patients is of interest and points to the need for further
studies to clarify the clinical significance of these isolates. The lack
of correlation between indirect evidence of infection (radiographic and
CRP levels), GP assessment of the need for antibiotics and pathogen
isolation are also of great interests and have important messages for
those working in the community.
The outcome conclusions from this study do however need to be treated with
some caution.
The authors state that outcomes were similar whether or not
antibiotics were used, but as this was an unrandomised observational
study, we cannot say that the groups of patients who were and were not
given antibiotics by the GPs in the study were comparable. The experienced
GP researchers in this study may well have had particular reasons for
giving or withholding antibiotics, and the significance of similar
reconsultation rates in these groups is open to interpretation.
In the accompanying editorial,[2] the authors state that systematic
reviews of randomised controlled trials of antibiotic prescription for
acute bronchitis do not support antibiotic treatment, and evidence based
educational initiatives aimed at GPs are advocated as one of the
strategies to alter clinical behaviour.
Having recently reviewed the
literature on this important clinical topic myself,[3] I cannot agree with
their assessment of the current evidence. The more recent review they
quote[4] has been criticised on methodological grounds, and the most
recent and extensive systematic review of this clinical problem, published
on the Cochrane database,[5] comes to very different conclusions,
commenting that "the review confirmed the impression of clinicians that
antibiotics have some beneficial effects in acute bronchitis". The
benefits are probably small and confined to certain patient subgroups, but
the quantification of benefit and the definition of the characteristics of
responder groups need further studies to delineate.
The world literature
currently consists of eight randomised controlled trials of variable
quality, some 20 years old, that use different antibiotic regimens and
different outcome measures. Several of these studies have concluded that
the antibiotic regimens used did improve outcomes.
The recent enquiry into community acquired pneumonia deaths in young
adults published in this journal,[6] revealed that the primary care
management of these patients at the severe end of lower respiratory tract
infection spectrum was deficient in many cases - three quarters of patients
had seen their GP for the illness without a correct diagnoses and few had
received antibiotics from their GP. There are many areas of uncertainty
remaining in this field, and while observational studies such as this help
to bring some clarity into this confused area of daily clinical practice,
well designed randomised controlled trials are still needed to produce the
evidence based guidance that GPs require. The current evidence is
inadequate to meet the challenge identified by Macfarlane et al,[1] that
of identifying the cohort of patients who will benefit from antibiotics.
Dr Mike Thomas
Clinical Research Fellow
Department of Primary Care Respiratory Medicine
University of Aberdeen, UK
References
(1) Macfarlane J, Holmes W, Gard P, Macfarlane R, Rose D, Weston V.
et al. Prospective study of the incidence, aetiology and outcome of lower
respiratory tract illness in the community. Thorax 2001;56:109-14.
(2) Steele K, Gormley G, Webb CH. Management of adult lower
respiratory tract infection in primary care. Thorax 2001;56:88.
(3) Thomas M. The management of acute respiratory tract infection in
adults in primary care. Primary Care Respiratory Journal 200;9:4-7.
(4) Fahey T, Stocks N, Thomas T. Quantitative systematic review of
randomised controlled trials comparing antibiotic with placebo for acute
cough in adults. BMJ 1998;316:910.
(5) Becker L, Glazier R, McIsaac W, and et al. Antibiotics for acute
bronchitis. Douglas R, Bridges-Webb C, Glasziou P, and et al. (1). 1998.
Oxford, Update software. Acute Respiratory Infections Module of the
Cochrane database of systematic reviews.
(6) Simpson JCG, Macfarlane JT, Watson J, Woodhead M. A national
confidential enquiry into community acquired pneumonia deaths in young
adults in England and Wales. Thorax 2000;55:1040-5.
If the abstract indicates correctly that children of totally non-smoking parents were not included in the study, I see that as a significant weakness.
The study found, as might be expected by many, an increase in contacts for asthma episodes among children most heavily exposed to environmental tobacco smoke (ETS).
However, it also found a non-significant but noteworthy decrease in asthma epi...
If the abstract indicates correctly that children of totally non-smoking parents were not included in the study, I see that as a significant weakness.
The study found, as might be expected by many, an increase in contacts for asthma episodes among children most heavily exposed to environmental tobacco smoke (ETS).
However, it also found a non-significant but noteworthy decrease in asthma episode contacts among those with "moderate" exposure as opposed to "low" exposure. If non-smoking parents (which would presumably usually
have children with *extremely* low exposure) had been included as a study group as well, we might have seen a continuation of the U-shaped curve indicating support for the idea that moderate levels of tobacco smoke in
the air might act in some way as a suppressor to asthma or asthma episodes
among children regularly exposed to such. Such a finding would also be in
line with the observed increase in asthma among American children over the
last few decades that seems to form a strikingly inverse relationship with
the exposure of American children to secondary smoke in the home and such
venues as fast-food restaurants and child care facilities.
Such a theory is of course anathema to the standard view that *any* exposure is "bad" for children and others, but it's possible that it could prove correct if properly studied.
I read with interest this article in Thorax and have been worried by the comments in "Pulse" which followed (9 December 2000).
The lack of information about the general practitioner (GP) consultations, and the non-
availability of records is alarming and dispiriting. Particularly when
nowadays much information is computerised and records can in emergency
situations, given the hard work of Health...
I read with interest this article in Thorax and have been worried by the comments in "Pulse" which followed (9 December 2000).
The lack of information about the general practitioner (GP) consultations, and the non-
availability of records is alarming and dispiriting. Particularly when
nowadays much information is computerised and records can in emergency
situations, given the hard work of Health Authorities pass between
practices in days.
It would be helpful to know what physical signs might have been
missed, indeed the selection process does not define presenting clinical
signs (beyond absence of life). So we have no denominator of cases where
we might need to think harder to avoid these events. As an habitual
"examiner" after ten years in general practice (and ten in hospital
medicine) I have been surprised by the paucity of physical signs in
patients with cough fever and purulent sputum. In these days of
evidenced based guidelines leading us away from the use of antibiotics we
need something hard to guide us to avoid the tragic but extremely rare
cases described.
It is a sad fact that subtle physical signs can be missed - even if
they are indeed present. Ten years in general practice has taught me
that serious illness changes quickly from minor symptoms to dire straits.
The only similar case in my recollection was a young woman sent home from
casualty to return moribund to hospital the same day with lobar pneumonia.
Steven Stern, MB ChB BSc MRCP
Principal in General Practice
The Code of Practice (Control and prevention of tuberculosis in the United Kingdom)[1] provides us with evidence based gold
standards for best practice in this field. The exception is of promoting
routine immigrant screening and the context within which it is
recommended.
I welcome a general health check for immigrants on arrival, but does
routine screening for tuberculosis needs to be part of it?...
The Code of Practice (Control and prevention of tuberculosis in the United Kingdom)[1] provides us with evidence based gold
standards for best practice in this field. The exception is of promoting
routine immigrant screening and the context within which it is
recommended.
I welcome a general health check for immigrants on arrival, but does
routine screening for tuberculosis needs to be part of it? Emphasis on
such screening implies convincing evidence. The Code’s reference to
Ormerod contradicts that assumption.[2][3]
Ormerod states that most tuberculosis is not evident on arrival.
Birmingham stopped adult screening some years back. Birmingham is
arguably the largest receiver of immigrants from the Indian subcontinent
to the UK. It was rare for even a single case to be recorded annually
when screening was practised in the city.
We must also take into account the cumulative radiological hazards of
screening; comparative cost benefits and effectiveness of diagnosing an
active case and its subsequent management as against relying on a disease
management policy alone. Human rights issue of equating immigration with
tuberculosis cannot be ignored.[4] [5]
The context in which immigrant screening is recommended is also worth
noting. Increased number of tuberculosis cases in the country does not
necessarily mean increased incidence. We have very poor measures of the
population base against which rates could be determined.
The natural immigrant population increase (some communities have an
above average birth rate) added to the number of new arrivals is an
unknown quantity since the last census a decade ago. The immigrant
population has also aged and could account for a higher age-specific
number of tuberculosis cases. Race and age specific rates may indeed be
falling while overall prevalence shows an increase. Much higher prevalence
of age-related diabetes in the immigrant population is an additional risk
factor for tuberculosis.[6]
It may well be that the increase in numbers is accompanied by
decrease in age and race specific rates due to improved living conditions
and better treatment facilities. The Code does add to the confusion,
referring to geographical preponderance when in reality the increase is
due to the presence of inhabitants from different parts of the world.
Areas such as Liverpool, though densely populated but with fewer immigrants
of Indian subcontinent origin, have a much lower overall prevalence of
tuberculosis.[7]
Tuberculosis is a slow evolving disease. It will be decades before
those who have migrated in the second half of the last century come into
equilibrium with rest of the indigenous population. There is the urgent
need to show whether this population is progressing towards that end or
that there is reversal in the secular trend of decrease of tuberculosis.
The latter would indeed be most worrying and call for the most detailed of
measures including screening.
We do not yet know of the impact of any control strategy on the trend
of tuberculosis. A disease management policy in affluent countries will at
least reduce the burden of disease and suffering. Diverting resource to a
screening programme will be counter productive.[8]
References
(1) BTS guidelines. Control and prevention of tuberculosis in the
United Kingdom: Code of Practice 2000. Thorax 2000;55:887-901.
(2) Ormerod LP. Tuberculosis screening and prevention in new
immigrants 1983-88. Respir Med 1990;84:269-71.
(3) Ormerod LP. Is immigrant screening for tuberculosis still
worthwhile? J Infect 1998;37:39-40.
(4) Bakhshi SS. screening immigrants at risk of tuberculosis. BMJ 1994;308:416.
(5) Bakhshi S. Detecting tuberculosis in new arrivals to UK. BMJ 2000;321:569.
(6) Stead WW, Dutt AK. Tuberculosis in the elderly. Semin Respir Infect 1989;4:189-97.
(7) Jeremy IH, Bakhshi SS, Ali S, Farrington CP. Ecological analysis
of ethnic differences in relation between tuberculosis and poverty. BMJ 1999;319:1031-4.
(8) Bwire R, et al. Tuberculosis screening among immigrants in The Netherlands: what is its contribution to public health? The Netherlands J Med 2000;56:63-71.
The observational data presented by Macfarlane et al on the aetiology of acute lower respiratory tract illness in the community[1] confirm that the often stated assertion that these illnesses are usually caused by viral infection is incorrect. The high prevalence of bacteriological and atypical pathogens, and in particular the high prevalence of C pneumoniae in these patients is of interest and points to the n...
If the abstract indicates correctly that children of totally non-smoking parents were not included in the study, I see that as a significant weakness.
The study found, as might be expected by many, an increase in contacts for asthma episodes among children most heavily exposed to environmental tobacco smoke (ETS).
However, it also found a non-significant but noteworthy decrease in asthma epi...
I read with interest this article in Thorax and have been worried by the comments in "Pulse" which followed (9 December 2000).
The lack of information about the general practitioner (GP) consultations, and the non- availability of records is alarming and dispiriting. Particularly when nowadays much information is computerised and records can in emergency situations, given the hard work of Health...
The Code of Practice (Control and prevention of tuberculosis in the United Kingdom)[1] provides us with evidence based gold standards for best practice in this field. The exception is of promoting routine immigrant screening and the context within which it is recommended.
I welcome a general health check for immigrants on arrival, but does routine screening for tuberculosis needs to be part of it?...
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