Low and colleagues present a very important paper. They should be given
the opportunity to remove my doubts about the validity of their findings:
They used a cross sectional design to determine incidence; however,
unless the average duration of conditions is known longitudinal studies
are required to determine this. The presented study assessed
disease status of self-selected participants over a period of...
Low and colleagues present a very important paper. They should be given
the opportunity to remove my doubts about the validity of their findings:
They used a cross sectional design to determine incidence; however,
unless the average duration of conditions is known longitudinal studies
are required to determine this. The presented study assessed
disease status of self-selected participants over a period of 2 years. For
most of the participants the disease status at the beginning of the 2-year
study period was unknown. This allows the calculation of the period
prevalence, “which represents the proportion of cases that exist within a
population at any point during a specified period of time. The numerator
thus includes cases tat were present at the start of the period plus new
cases that developed during this time”.[1]
For conditions with a long duration (such as asymptomatic infection in
women) the incidence may be considerably lower than the period prevalence.
The key message of the paper is that rates of gonorrhoea and chlamydia diagnosis differ between different black ethnic groups. As the
authors mention in their discussion “differential sexual heath service use
by the ethnic groups may account for some of the observed disparity”.
Knowledge, attitudes, individual and group norms, resources and ease of
access determine care seeking. Ease of access should be similar for
members of different ethnic groups living is the same ward. Maybe Low and
colleagues would like to present the data controlling for confounding by
ward of residence.
References
(1) Hennekens CH, Burning JE. Measures of disease frequency in Epidemiology
in Medicine. Ed, Mayrent SL. Boston 1987:54-100.
Mr McElborough considers it unfortunate that reference labs may have
developed their algorithms in the case of conventional syphilis diagnosis
and these do little to help with HIV coinfected patients. Guidelines for
serological diagnosis in coexisting HIV infection, neurosyphilis and
congenital infection are currently under preparation by the (Public Health Laboratory Service) PHLS Syphilis
Forum and will...
Mr McElborough considers it unfortunate that reference labs may have
developed their algorithms in the case of conventional syphilis diagnosis
and these do little to help with HIV coinfected patients. Guidelines for
serological diagnosis in coexisting HIV infection, neurosyphilis and
congenital infection are currently under preparation by the (Public Health Laboratory Service) PHLS Syphilis
Forum and will be available later this year.
In Edinburgh, the syphilis/HIV co-infected population may be much
smaller than in Brighton, but we have not experienced the serological
problems that Mr McElborough refers to. It would be most helpful if Mr
McElborough published details of the atypical serology that he has
encountered in coinfected patients.
Hugh Young
Medical Microbiology
Edinburgh University Medical School
Teviot Place, Edinburgh EH8 9AG, UK
Whilst it is comforting that some research is finally being carried
out in depth on the risk of STIs amongst women who have sex with women
(WSW), any conclusions drawn from this study for WSW in general need to be
handled with a great deal of caution when one looks at the make-up of the
subjects and controls.
For example, over twice as many of the WSW as the control group were
current sex workers;...
Whilst it is comforting that some research is finally being carried
out in depth on the risk of STIs amongst women who have sex with women
(WSW), any conclusions drawn from this study for WSW in general need to be
handled with a great deal of caution when one looks at the make-up of the
subjects and controls.
For example, over twice as many of the WSW as the control group were
current sex workers; 38% of the WSW had had a previous termination of
pregnancy; nearly six times as many of the WSW had a history of injecting
drug use.
The researchers themselves say their "clinic population... may not be representative of the WSW in the general community". This is an understatement - and any reporting of this study must make very clear statements about the dangers of inappropriate conclusions about STIs
amongst women who have sex with women generally.
In our area the high HIV prevalence has made the interpretation of
syphilis tests paticularly problematic. Coinfected patients do appear to
reactivate their treponemal infection or possibly reinfection with a
different "strain" in the presence of profound immunosuppression. As with
some other agents IgM can persist for several years with peaks and
troughs! Non-treponemal tests are uniformly negative whilst...
In our area the high HIV prevalence has made the interpretation of
syphilis tests paticularly problematic. Coinfected patients do appear to
reactivate their treponemal infection or possibly reinfection with a
different "strain" in the presence of profound immunosuppression. As with
some other agents IgM can persist for several years with peaks and
troughs! Non-treponemal tests are uniformly negative whilst TPHA levels
can fluctuate widely! It is perhaps unfortunate that reference labs may
have developed their algorithms in the face of conventional syphilis
diagnosis - these do little to help with HIV coinfected patients.
Denis McElborough
Public Health Laboratory
Royal Sussex County Hospital
Eastern Road, Brighton, UK
Fether at al present a very interesting case control study on
STIs in women who have sex with women (WSW). This was not a community
based sample and thus prone to selection bias. In order to appreciate the
results in full it would help to know how cases and controls were identified
and how controls were selected.
As bisexual or homosexual orientation may
be difficult to disclose even in a sympat...
Fether at al present a very interesting case control study on
STIs in women who have sex with women (WSW). This was not a community
based sample and thus prone to selection bias. In order to appreciate the
results in full it would help to know how cases and controls were identified
and how controls were selected.
As bisexual or homosexual orientation may
be difficult to disclose even in a sympathetic and non-judgemental
setting, studies using self-reported sexual orientation to determine
case or control status will always have a degree of differential
misclassification.
It is likely that WSW who volunteer this information
differ not only from women who do not have sex with women but also from
WSW who do not volunteer the information but admit it when prompted, and
from those who do not admit it even when prompted.
Without this information it is difficult to determine the importance of
various prevalence quoted in the paper. All I learn from this paper at
present is that women who have sex with women also take other risks.
I commend Shamanesh et al for their searching and informed
account of the impact of globalisation on the world AIDS problem.
Revisiting Alma Ata 1978: the existence of gross inequalities between
advantaged and disadvantaged peoples is "politically, socially and
economically" unacceptable.
22 years on, are we closer to the ideal of "health for all" or further
away. When will we learn?
Low and colleagues present a very important paper. They should be given the opportunity to remove my doubts about the validity of their findings: They used a cross sectional design to determine incidence; however, unless the average duration of conditions is known longitudinal studies are required to determine this. The presented study assessed disease status of self-selected participants over a period of...
Mr McElborough considers it unfortunate that reference labs may have developed their algorithms in the case of conventional syphilis diagnosis and these do little to help with HIV coinfected patients. Guidelines for serological diagnosis in coexisting HIV infection, neurosyphilis and congenital infection are currently under preparation by the (Public Health Laboratory Service) PHLS Syphilis Forum and will...
Whilst it is comforting that some research is finally being carried out in depth on the risk of STIs amongst women who have sex with women (WSW), any conclusions drawn from this study for WSW in general need to be handled with a great deal of caution when one looks at the make-up of the subjects and controls.
For example, over twice as many of the WSW as the control group were current sex workers;...
In our area the high HIV prevalence has made the interpretation of syphilis tests paticularly problematic. Coinfected patients do appear to reactivate their treponemal infection or possibly reinfection with a different "strain" in the presence of profound immunosuppression. As with some other agents IgM can persist for several years with peaks and troughs! Non-treponemal tests are uniformly negative whilst...
Dear Editor
Fether at al present a very interesting case control study on STIs in women who have sex with women (WSW). This was not a community based sample and thus prone to selection bias. In order to appreciate the results in full it would help to know how cases and controls were identified and how controls were selected.
As bisexual or homosexual orientation may be difficult to disclose even in a sympat...
I commend Shamanesh et al for their searching and informed account of the impact of globalisation on the world AIDS problem. Revisiting Alma Ata 1978: the existence of gross inequalities between advantaged and disadvantaged peoples is "politically, socially and economically" unacceptable. 22 years on, are we closer to the ideal of "health for all" or further away. When will we learn?
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