Treatment of Chlamydial Infections

Sexually transmitted infections (STIs) are a major health problem with an estimated burden of disease transmission as high as one million new cases per day globally. Chlamydia trachomatis, a member of the genus Chlamydia, is one of the most common and curable causative agents of STIs. C. trochomatis infections usually affect sexually active young adults and adolescents; and are composed of a broad spectrum of diseases varying from asymptomatic infection to severe genito-urinary infection leading to infertility and acute or chronic ocular infection (trachoma), which may result in blindness and pneumonia. Among the members of the genus Chlamydia, there are also two pathogenic species, Chlamydia pneumoniae and Chlamydia psittaci which are responsible for acute respiratory tract infections and febrile illness in humans. The incidence, pathophysiology, and diagnostic methods are discussed in detail in the previous chapters. The purpose of this chapter is to elucidate the management of infections due to C. trachomatis, C. pneumoniae, and C. psittaci including antibiotic susceptibility and resistance mechanisms, treatment recommendations for ocular infections, genito-urinary and respiratory tract infections, and management of sex partners, pregnant women, neonates, and children according to the latest data.

Universal lymphogranuloma venereum (LGV) testing of rectal chlamydia in men who have sex with men and detection of asymptomatic LGV

BACKGROUND

Lymphogranuloma venereum (LGV) is caused by Chlamydia trachomatis serovars L1-L3. This study determined the positivity for LGV testing before and after introduction of universal LGV testing of positive rectal Chlamydia trachomatis samples in men who have sex with men (MSM).

METHODS

From March 2015 to February 2018, MSM with rectal C. trachomatis were not routinely tested for LGV at the Melbourne Sexual Health Centre unless they had HIV or symptoms of proctitis. From February 2018, universal testing for LGV of all positive rectal C. trachomatis specimens in men over the age of 25 years, regardless of symptoms was undertaken. LGV positivity was defined as the detection of LGV-associated C. trachomatis serovars.

RESULTS

There were 3429 and 4020 MSM who tested positive for rectal chlamydia in the selective and universal LGV-testing periods, respectively. Of the total 3027 assessable specimens in both periods, 97 (3.2%; 95% CI 2.6% to 3.9%) specimens tested positive for LGV. LGV positivity in the selective testing period was higher than in the universal testing period (6.6% (33/502) vs 2.5% (64/2525), p<0.001). The proportion of LGV cases that were asymptomatic increased from 15.2% (5/33) in the selective testing period to 34.4% (22/64) in the universal testing period (p=0.045). Of the 70 symptomatic LGV cases symptoms included rectal discharge (71.4%, n=45) and rectal pain (60.0%, n=42).

CONCLUSION

Universal LGV testing of all positive rectal chlamydia samples in MSM compared with selective testing led to the detection of asymptomatic rectal LGV, which constituted 34% of rectal LGV cases.

Knowing the unknown: The underestimation of monkeypox cases. Insights and implications from an integrative review of the literature

Monkeypox is an emerging zoonotic disease caused by the monkeypox virus, which is an infectious agent belonging to the genus Orthopoxvirus. Currently, commencing from the end of April 2022, an outbreak of monkeypox is ongoing, with more than 43,000 cases reported as of 23 August 2022, involving 99 countries and territories across all the six World Health Organization (WHO) regions. On 23 July 2022, the Director-General of the WHO declared monkeypox a global public health emergency of international concern (PHEIC), since the outbreak represents an extraordinary, unusual, and unexpected event that poses a significant risk for international spread, requiring an immediate, coordinated international response. However, the real magnitude of the burden of disease could be masked by failures in ascertainment and under-detection. As such, underestimation affects the efficiency and reliability of surveillance and notification systems and compromises the possibility of making informed and evidence-based policy decisions in terms of the adoption and implementation of ad hoc adequate preventive measures. In this review, synthesizing 53 papers, we summarize the determinants of the underestimation of sexually transmitted diseases, in general, and, in particular, monkeypox, in terms of all their various components and dimensions (under-ascertainment, underreporting, under-detection, under-diagnosis, misdiagnosis/misclassification, and under-notification).

Sexually Transmitted Infections Treatment Guidelines, 2021

These guidelines for the treatment of persons who have or are at risk for sexually transmitted infections (STIs) were updated by CDC after consultation with professionals knowledgeable in the field of STIs who met in Atlanta, Georgia, June 11–14, 2019. The information in this report updates the 2015 guidelines. These guidelines discuss 1) updated recommendations for treatment of Neisseria gonorrhoeae, Chlamydia trachomatis, and Trichomonas vaginalis; 2) addition of metronidazole to the recommended treatment regimen for pelvic inflammatory disease; 3) alternative treatment options for bacterial vaginosis; 4) management of Mycoplasma genitalium; 5) human papillomavirus vaccine recommendations and counseling messages; 6) expanded risk factors for syphilis testing among pregnant women; 7) one-time testing for hepatitis C infection; 8) evaluation of men who have sex with men after sexual assault; and 9) two-step testing for serologic diagnosis of genital herpes simplex virus. Physicians and other health care providers can use these guidelines to assist in prevention and treatment of STIs.

Whole-Genome Enrichment and Sequencing of Chlamydia trachomatis Directly from Patient Clinical Vaginal and Rectal Swabs

Chlamydia trachomatis, an obligately intracellular bacterium, is the most prevalent cause of bacterial sexually transmitted infections (STIs) worldwide. Numbers of U.S. infections of the urogenital tract and rectum have increased annually. Because C. trachomatis is not easily cultured, comparative genomic studies are limited, restricting our understanding of strain diversity and emergence among populations globally. While Agilent SureSelect^XT target enrichment RNA bait libraries have been developed for whole-genome enrichment and sequencing of C. trachomatis directly from clinical urine, vaginal, conjunctival, and rectal samples, public access to these libraries is not available. We therefore designed an RNA bait library (34,795 120-mer probes based on 85 genomes, versus 33,619 probes using 74 genomes in a previous one) to augment organism sequencing from clinical samples that can be shared with the scientific community, enabling comparison studies. We describe the library and limit of detection for genome copy input, and we present results of 100% efficiency and high-resolution determination of recombination and identical genomes within vaginal-rectal specimen pairs in women. This workflow provides a robust approach for discerning genomic diversity and advancing our understanding of the molecular epidemiology of contemporary C. trachomatis STIs across sample types, geographic populations, sexual networks, and outbreaks associated with proctitis/proctocolitis among women and men who have sex with men.IMPORTANCE Chlamydia trachomatis is an obligate intracellular bacterium that is not easily cultured, which limits our understanding of urogenital and rectal C. trachomatis transmission and impact on morbidity. To provide a publicly available workflow for whole-genome target enrichment and sequencing of C. trachomatis directly from clinical urine, vaginal, conjunctival, and rectal specimens, we developed and report on an RNA bait library to enrich the organism from clinical samples for sequencing. We demonstrate an increased efficiency in the percentage of reads mapping to C. trachomatis and identified recombinant and identical C. trachomatis genomes in paired vaginal-rectal samples from women. Our workflow provides a robust genomic epidemiologic approach to advance our understanding of C. trachomatis strains causing ocular, urogenital, and rectal infections and to explore geo-sexual networks, outbreaks of colorectal infections among women and men who have sex with men, and the role of these strains in morbidity.

Increasing trends of lymphogranuloma venereum among HIV-negative and asymptomatic men who have sex with men, the Netherlands, 2011 to 2017

Introduction

Lymphogranuloma venereum (LGV), an invasive form of Chlamydia trachomatis infection, has been reported among (mainly HIV-positive) men who have sex with men (MSM) since 2003. In the Netherlands, LGV testing recommendations changed from selective to universal testing in 2015. Changes in tested populations could have led to incomparable LGV positivity rates over time.

Aim

We investigated LGV trends among MSM attending Centres for Sexual Health using surveillance data between 2011 and 2017.

Methods

LGV positivity was calculated among MSM tested for rectal Chlamydia infection and MSM tested specifically for LGV. With multivariable logistic regression analysis, the association between years and LGV was adjusted for testing indicators and determinants.

Results

We included 224,194 consultations. LGV increased from 86 in 2011 to 270 in 2017. Among LGV-positives, proportions of HIV-negative and asymptomatic MSM increased from 17.4% to 45.6% and from 31.4% to 49.3%, respectively, between 2011 and 2017. Among MSM tested for rectal chlamydia, LGV positivity increased from 0.12% to 0.33% among HIV-negatives and remained stable around 2.5% among HIV-positives. Among LGV-tested MSM, LGV positivity increased from 2.1% to 5.7% among HIV-negatives and from 15.1% to 22.1% among HIV-positives. Multivariable models showed increased odds ratios and significant positive associations between years and LGV.

Conclusions

Although increased testing and changes in LGV incidence are difficult to disentangle, we found increasing LGV trends, especially when corrected for confounding. LGV was increasingly attributed to HIV-negative and asymptomatic MSM, among whom testing was previously limited. This stresses the importance of universal testing and continuous surveillance.

Anatomical site prevalence and genotypes of Chlamydia trachomatis infections among men who have sex with men: a multi-site study in China

Background

Chlamydia trachomatis (CT) infection is one of the most pervasive sexually transmitted infections and has high prevalence in urogenital and extra-urogenital sites among men who have sex with men (MSM). This study investigated anatomical site-specific prevalence and genotypes of CT among MSM recruited from three geographic areas in China.

Methods

We collected urine specimens and anorectal, pharyngeal swab specimens from 379 MSM. CT infection was identified using polymerase chain reaction and CT genotyping was determined by sequences of the ompA gene.

Results

The results indicated that the overall prevalence of CT infection was 18.2% (95% confidence intervals [CIs], 13.9–22.5%) and significantly different between the cities (p = 0.048). The infection was most common at the anorectal site (15.6, 95%CIs 11.6–19.5%) followed by urethral (3.2, 95%CIs 1.4–5.0%) and oropharyngeal sites (1.6, 95%CIs 0.3–2.9%). Genotypes D and G were the most common CT strains in this population but genotype D was significantly predominated in Nanjing while genotype G was in Wuhan. No genotype related to lymphogranuloma venereum was found. CT infection was significantly related to the infection of Neisseria gonorrhoeae (adjusted odds ratio [aOR] 14.27, 95%CIs 6.02–33.83, p < 0.001) and age. Men older than 40 years old were less likely to have a CT infection as compared to men under 30 years old (aOR 0.37, 95% CIs 0.15–0.93, p = 0.03).

Conclusion

The high CT infection prevalence, particularly in the anorectal site, among MSM suggests the necessity to development an integrated CT screening and treatment program specifically focusing on this high-risk population. Surveillance of CT infections should be improved by including both infection and genotype based surveys into the current surveillance programs in China.

Lymphogranuloma venereum in Spain, 2005-2015: A literature review

Lymphogranuloma venereum (LGV) was an unusual disease in Europe until 2003, when several outbreaks among men who have sex with men (MSM) emerged. Since 2015, LGV has been included notifiable disease in Spain. Our aim is to review LGV cases published in Spain from 2005 to 2015. Fourteen studies met the inclusion criteria describing cases in 7autonomous regions. Most cases were MSM, Spaniards, aged between 30-45, with anorectal syndrome. L2 was the predominant serotype isolated. More than 60% of the cases among MSM were co-infected with HIV and nearly half of those reported another concurrent STI. Since the first LGV case published more than 10years ago, this disease has spread across Spain. Epidemiological and clinical characteristics of cases are similar to cases described in Europe. Implementation of national surveillance will improve information about LGV's magnitude and its evolution, key elements for its control.

Observational study of anorectal Chlamydia trachomatis infections in France through the lymphogranuloma venereum surveillance network, 2010-2015

The objective of this article is to describe the epidemiology of lymphogranuloma venereum (LGV) and non-LGV Chlamydia trachomatis anorectal infections in France and to examine the characteristics of the affected populations via a voluntary sentinel surveillance system for LGV between 2010 and 2015. Anorectal samples positive for C. trachomatis (CT) were sent by the participating laboratories to the National Reference Center for CT for LGV identification. Biological and clinical data were collected by biologists and clinicians. There were 1740 LGV episodes and 2248 non-LGV episodes. Continuous monitoring highlighted a sharp increase in the number of LGV and non-LGV anorectal infections, which were 2.3-fold and 6.5-fold, respectively. Most of the infections occurred in men who have sex with men. LGV patients were older than non-LGV patients and were more frequently human immunodeficiency virus (HIV)-positive compared to non-LGV patients. Anorectal LGV was significantly associated with residence in Paris, HIV co-infection, concurrent syphilis and bloody anal discharge. Undocumented patient characteristics were strongly associated with anorectal LGV. The anorectal LGV epidemic is poorly controlled in France. Early detection and prompt treatment of patients and their sexual partners are required to prevent transmission in the context of pre-exposure prophylaxis (PrEP) for HIV infection.

Isolated bilateral inguinal lymphadenopathy in the absence of other symptoms, due to LGV in known HIV-positive MSM: is it more common than we think?

The current resurgence of lymphogranuloma venereum (LGV) has drawn most attention to its potential for causing proctitis; however, this case highlights the need for awareness of LGV as a cause of isolated painful bilateral inguinal lymphadenopathy in a high-risk population and the importance of routine screening for LGV. We describe a case of a 37-year-old HIV positive man, in the population of men who have sex with men (MSM) who presented with bilateral enlarged inguinal lymph nodes and no other symptoms or signs. Urine nucleic acid amplification test was positive for chlamydia LGV-specific DNA. Tests from other sites were negative.

Rapid increase in lymphogranuloma venereum in men who have sex with men, United Kingdom, 2003 to September 2015

United Kingdom (UK) national data show a sharp increase in diagnoses of lymphogranuloma venereum (LGV) since 2012. Most cases are in men who have sex with men (MSM) living in London, with high rates of co-infection with HIV and other sexually transmitted infections. In light of these data, and the recent finding that one quarter of LGV infections may be asymptomatic, clinicians should be vigilant in testing for LGV, including in asymptomatic HIV-positive MSM.

High Prevalence of Co-Infections by Invasive and Non-Invasive Chlamydia trachomatis Genotypes during the Lymphogranuloma Venereum Outbreak in Spain

The evolution of Chlamydia trachomatis is mainly driven by recombination events. This fact can be fuelled by the coincidence in several European regions of the high prevalence of non-invasive urogenital genotypes and lymphogranuloma venereum (LGV) outbreaks. This scenario could modify the local epidemiology and favor the selection of new C. trachomatis variants. Quantifying the prevalence of co-infection could help to predict the potential risk in the selection of new variants with unpredictable results in pathogenesis or transmissibility. In the 2009-2013 period, 287 clinical samples with demonstrated presence of C. trachomatis were selected. They were divided in two groups. The first group was constituted by 137 samples with C. trachomatis of the LGV genotypes, and the second by the remaining 150 samples in which the presence of LGV genotypes was previously excluded. They were analyzed to detect the simultaneous presence of non-LGV genotypes based on pmpH and ompA genes. In the first group, co-infections were detected in 10.9% of the cases whereas in the second group the prevalence was 14.6%, which is the highest percentage ever described among European countries. Moreover, bioinformatic analyses suggested the presence among men who have sex with men of a pmpH-recombinant variant, similar to strains described in Seattle in 2002. This variant was the result of genetic exchange between genotypes belonging to LGV and members of G-genotype. Sequencing of other genes, phylogenetically related to pathotype, confirmed that the putative recombinant found in Madrid could have a common origin with the strains described in Seattle. Countries with a high prevalence of co-infections and high migration flows should enhance surveillance programs in at least their vulnerable population.

[Lymphogranuloma venereum: the first Hungarian cases]

Lymphogranuloma venereum is a sexually transmitted infection caused by the Chlamydia trachomatis serovars L1-3. It has been found to be endemic in tropical countries. In the last decades several cases have been reported in Western Europe, particularly in men who have sex with men population infected with human immunodeficiency virus. The authors present three cases of lymphogranuloma venereum infections, observed at their department in 2013 and 2014. The three human immunodeficiency virus infected patients who belonged to men who have sex with men population had casual sexual contacts in Western Europe. The symptoms included urethral discharge, discomfort and inguinal lymphadenomegaly in two patients, and rectal pain, discharge and perianal ulceration in one patient. The diagnosis was confirmed by nucleic acid amplification test performed in samples obtained from urethral discharge and exudate of perianal ulcer; lymphogranuloma venereum 2b serovars were demonstrated in two patients and serovar 2 in one patient. Doxycyclin (daily dose of two times 100 mg for 21 days) resolved the symptoms in all cases. The authors conclude that lymphogranuloma venereum is a diagnostic challenge in Hungary, too. It is important to be aware of the altered clinical features of this disease to prevent complications and spreading.

Recent advances in understanding and managing Chlamydia trachomatis infections

Worldwide, Chlamydia trachomatis infections rank among the most common sexually transmitted infections (STI), and cause notable reproductive morbidity in women. Although advances in highly accurate and non-invasive diagnostic testing have allowed for better estimation of the burden of disease—especially the asymptomatic state—we still lack a true point-of-care test, and many infections go undetected and untreated. Moreover, limited resources and effort for managing sexual partners of those in whom infection is actually identified comprise a major challenge to control. Here, we review the current state of understanding of this common infection, and efforts to control it.