eLetters

198 e-Letters

  • Error in the calculation of person-time in the before-PrEP period by Beymer et al.

    Error in the calculation of person-time in the before-PrEP period by Beymer et al.

    S.H. Hulstein, E. Hoornenborg,  M.F. Schim van der Loeff

    Department of Infectious Diseases, GGD Amsterdam

    Studies on STI incidence and PrEP use are often hampered by the absence of STI incidence data in the period before PrEP; Beymer et al.1  set out to improve on this. They report on the STI incidence before and after initiation of PrEP in a cohort of men who have sex with men (MSM) at the Los Angeles LGBT Center, California, US. We fear that there are some flaws in the analysis, which may affect the conclusions.

    The analysis was based on 275 men who were tested at least once in the period before PrEP was started, and at least once after PrEP was started. The reported persontime in the before- PrEP period was just over half the person-time after PrEP initiation (93.60 versus 168.93), but the numbers of tests before and after PrEP initiation were not very different: 755 and 908, respectively. This discrepancy could not be explained by differences in their frequency of STI testing, which were reported to be similar in the before- and after-PrEP period. An explanation  is that the person-time before the first STI visit was not taken into account. This would mean that the person-time in the before-PrEP period was underestimated, in turn leading to an artificially high before-PrEP STI incidence....

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  • Research on Mycoplasma genitalium is more important than expanding testing

    Prevalence of Mycoplasma genitalium

    Response to: Taylor-Robinson D and Ong J

    Authors: Nicola Low, Lukas Baumann, Manuel Cina, Myrofora Goutaki, Hammad Ali, Dianne Egli-Gany

    Correspondence to: Nicola Low, Professor of Epidemiology and Public Health, Institute of Social and Preventive Medicine, University of Bern, Mittelstrasse 43, 3012 Bern, Switzerland. nicola.low@ispm.unibe.ch; Tel: +41 31 631 30 92

    Title: Research on Mycoplasma genitalium is more important than expanding testing

    We are glad that Taylor-Robinson and Ong offer some support for the conclusion of our systematic review,1 that asymptomatic populations, in the community or in clinics, should not be tested routinely for M. genitalium. The first British Association of Sexual Health and HIV (BASHH) guideline about the management of Mycoplasma genitalium, published on 8th July 2018, supports this conclusion.2 We would like to clarify, however, that the absence of evidence for clinical and public health benefit of screening3 and the harm of inducing de novo mutations and spreading resistance to macrolide antimicrobials4 are more important than economic considerations.

    Taylor-Robinson and Ong’s statement that “testing worldwide should continue to support or modify this conclusion”5 could lead to pro...

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  • Prevalence of Mycoplasma genitalium

    The work by Baumann et al.(1) is valuable because it indicates populations for which screening for Mycoplasma genitalium (MG)) is not worthwhile economically. However, as molecular detection tests are now available commercially, testing worldwide should continue to support or modify this conclusion and so help in the development of management guidelines and also provide data for MG modelling.
    Another aspect of infection which requires more attention is the precise role of MG in balanoposthitis, epididymitis,, chronic prostatitis, reactive arthritis, and, of course, pelvic inflammatory disease, all of which, apart from chronic prostatitis, have some association with MG (2).
    In addition, it is noteworthy that Mycoplasma pneumoniae (MP), which infects the respiratory tract, and is also responsible for some autoimmune side effects, does so in early childhood without causing disease. The latter usually occurs as an immunological response to reinfection later in life. MG is different genomically from MP but has much in common antigenically and might behave in a similar way to MP. Could asymptomatic MG infection, which is seen occasionally, be an example of this? Potentiation or even inhibition of MG infection in the genital tract by MP infection in the respiratory tract earlier in life is also possible. This idea is not supported by studies in mice, but the human situation might be quite different. In this regard, use of an existing specific serological test for MG m...

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  • Response to van Aar et al.

    Dear Editor,

    We read with interest the short report by van Aar et al. discussing potential implications of chlamydia expedited partner therapy (EPT) which entails patient delivered partner therapy.1 The authors highlight a number of factors which may influence the benefit-risk balance of providing EPT, many of which resonate with our experience of Accelerated Partner Therapy (APT).2 APT is an adaptation of EPT, which includes a telephone consultation between the sex partner and prescriber (to meet UK prescribing guidance), provision of a self-sampling kit for sexually transmitted infections (STIs) and HIV for a sex partner in addition to antibiotics and information on STIs and HIV. APT has been piloted among predominately heterosexual contacts of chlamydia and gonorrhoea.3

    The authors report a chlamydia positivity rate of 34.2% among chlamydia-notified partners in the Netherlands and proposed that the use of EPT for all contacts risks exposing the majority of contacts to potentially unnecessary antimicrobial therapy. Furthermore, just over 1% of these contacts also had gonorrhoea, accounting for about 10% of all gonorrhoea infections detected during the study time period, raising additional concerns about inadequate therapy and antimicrobial resistance.

    In England in 2016, chlamydia positivity among chlamydia contacts attending specialist sexual health services (SHS) was 40%, representing 19% of all chlamydia diagnoses made in SHS that year.4 This is...

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  • Impact of Expedited Partner Therapy (EPT) Implementation on Chlamydia Incidence in the USA

    Impact of Expedited Partner Therapy (EPT) Implementation on Chlamydia Incidence in the USA
    Letter to the Editor:
    Assuming that a sexual partner has only one Sexually Transmitted Infection (STI) is a dangerous practice and should be discouraged. The Expedient Partner Therapy implementation on Chlamydia is one such assumption. In a study conducted by (Zemouri, Wi, Kiarie, Seuc, Moqasale et.al 2016) they highlighted that Sexually Transmitted Infection (STI) case management is one of the top priorities in controlling STIs to break the chain of infection and transmission. They further reiterated that Syndromic case management provides a standardized evidence-based approach using clinical management algorithms, and flowcharts that can be used consistently across providers. Clinicians that treat patients with STIs should be cognizant that Expedited Partner Treatment is inadequate because there is at least a third infected sexual partner other than the partner being treated.
    Another factor that should be considered when administering Expedited Partner Therapy is the possibility, of the partner, manifesting other symptoms of a STI to be treated that has not yet been identified in the patient. It is useful to administer the risk score test which is a 6 point research base quiz to each patient being treated for STI. These questions can only be answered by the patient for it to be considered reliable. Each question has a number of points assigned to potential ans...

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  • This study did not measure vertical transmission of Chlamydia trachomatis

    The authors estimated vertical transmission of Chlamydia trachomatis by a retrospective analysis using national registry data and clinical records and concluded that transmission was much lower (<2%) than the rate commonly quoted (50-70%). Their suggested explanation is that the modern use of highly sensitive NAATs detects nonviable chlamydiae so that mothers testing positive could actually be noninfectious whereas older studies based on use of culture only identified infectious pregnant women. That is not a likely explanation for such a big difference. When NAAT performance with cervical swabs was evaluated about 2/3 of NAAT positive specimens were culture positive.
    A more likely explanation comes from examining their case definition. It is not chlamydial infection, but rather laboratory confirmed cases of chlamydial conjunctivitis or pneumonia. And that is very different. When prospective studies were being done in San Francisco 175 infants born to chlamydia infected mothers were followed: 31 (18%) developed pneumonia; 29 (17%) conjunctivitis; 64 (37%) were culture positive and 105 (60%) had serologic evidence of infection. Thus there were many more infections than cases of conjunctivitis and pneumonia. But the difference between cases of disease and infection in the Finnish material is probably greater. In the prospective study there were cases of very mild disease that would likely not have been diagnosed in ordinary circumstances (seeing the whole clinical s...

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  • Data from the iPrEx Trial Does Not Support This Hypothesis

    The authors impute a biological mechanism to the high incidence of syphilis in men who have sex with men using anti-retroviral drugs (in particular, HAART). We suggest, empiric data do not support the biological hypothesis, and behavioral explanations (i.e. increased condomless sex and selection of higher risk partners) are supported by stronger evidence.

    Randomized double-blind trials of pre-exposure prophylaxis (PrEP) for HIV prevention [1] provide a rigorous test of the author’s hypothesis. The methodological strength includes an unconfounded and clearly unexposed control group and an exposed group which received an agent that would putatively increase susceptibility — tenofovir disoproxil fumarate (TDF) co-formulated with emtricitabine (FTC). A unique feature is that these trials were blinded and PrEP was unproven that the time trials were undertaken; hence, we would not expect that the TDF/FTC-exposed group would adopt higher risk practices.

    An analysis of the iPrEx trial [2], a randomized PrEP trial in men who have sex with men/trans women, found [1] a relative rate of syphilis acquisition for TDF/FTC of 1.14 with a 0.95 confidence interval (0.90 to 1.45) compared to placebo. Incident syphilis, can be difficult to differentiate from a previous infection. Among those with a negative rapid plasma reagin titer at screening the relative rate of an on-study infection was 1.03, 0.95 CI (0.76 to 1.38). Adherence, was low in the iPrEx study and when pharmaco...

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  • Syphilis Presents Differently to Chlamydia and Gonorrhea Which May Impact Subsequent Behavior
    Aaron M Steppe

    I'm writing to ask if the authors considered an alternate hypothesis: perhaps the symptoms of primary infection with syphilis are easier to ignore than chlamydia and gonorrhea--the latter two often cause painful urination and discharge, while with syphilis (in men) a chancre often appears in the genital area, usually (but not always) on the penis. These sores are often painless.

    To me it seems quite reasonable...

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  • Re: Trimming the estimate: Unmeasured confounding in the association between pubic hair grooming and sexually transmitted infections
    Benjamin N Breyer

    As few studies have examined the relation between pubic hair grooming and sexually transmitted infections (STIs), we took advantage of nationally representative survey data to begin to explore this possible association and to develop hypotheses for future prospective studies. In our analysis, we observed a positive association between self-reported pubic hair grooming and STI history, which we interpreted in several poss...

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  • Street and Labour Children; Special Group for Elimination of Viral Hepatitis in Iran
    Seyed Moayed Alavian

    Dear editor,

    We read with much interest the recently published article by Foroughi et al. [1] in your journal. They have demonstrated that prevalence of HIV, hepatitis B virus (HBV), and hepatitis C virus (HCV) infections among street and labour child are 4.5%, 1.7% and 2.6% in Iran, respectively and well discussed about HIV infection in this population, However, we would like to highlight some points about HBV a...

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