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Chlamydia spp. are a group of obligate intracellular pathogens causing a number of diseases in animals and humans. Avian chlamydiosis (AC), caused by Chlamydia psittaci (C. psittaci) as well as new emerging C. avium, C. gallinacea and C. ibidis, have been described in nearly 500 avian species worldwidely. The Crested Ibis (Nipponia nippon) is a world endangered avian species with limited population and vulnerable for various infections. To get a better understanding of the prevalence of Chlamydia spp. in the endangered Crested Ibis, faecal samples were collected and analysed. The results confirmed that 20.20% (20/99) of the faecal samples were positive for Chlamydiaceae and were identified as C. ibidis with co-existence of C. psittaci in one of the 20 positive samples. In addition, ompA sequence of C. psittaci obtained in this study was classified into the provisional genotype Matt116, while that of C. ibidis showed high genetic diversity, sharing only 77% identity with C. ibidis reference strain 10-1398/6. We report for the first time the presence of C. ibidis and C. psittaci in the Crested Ibis, which may indicate a potential threat to the endangered birds and should be aware of the future protection practice.

Prior studies have demonstrated that both bacterial vaginosis (BV) and sexually transmitted infections (STIs) are strong independent risk factors for subsequent STI. In observational studies of this biological enhancement (BE) hypothesis, it is important to adjust for the risk of STI exposure so that the independent effect of BE can be assessed. We sought to model if two markers of local sexual network (partner concurrency and cumulative number of STIs) represented residual confounding in the models of risk for subsequent infection in a study that screened 3620 women for STIs every 3 months for a year. Mixed-effects logistic regression was used to calculate the odds ratios for an incident diagnosis ofChlamydia trachomatis,Neisseria gonorrhoeae,Trichomonas vaginalisand BV following a diagnosis of any of these four at the prior visit, controlling for the cumulative number of STIs and partner concurrency variables. We found that partner concurrency and cumulative number of STIs were each associated with incident infection, and in general, controlling for these variables reduced the strength of the association between prior and incident infections. We conclude that the frequently found association between prior and incident STIs is associated with both BE and sexual network structure.

SUMMARYIdentification of priority populations such as men who have sex with men (MSM) is important in surveillance systems to monitor trends of sexually transmitted infections (STIs). We explored using routinely collected non-behavioural data as a means to establish MSM status in surveillance by assessing anorectal swab as a marker of male-to-male sexual exposure. We used chlamydia testing data from a sexual health clinic, 2007–2012. Men reporting any male sexual partner(s) in the previous 12 months were considered MSM. The dataset was split into development and validation samples to develop a univariate predictive model and assess the model fit. The dataset included 30 358 individual men and 48 554 episodes of STI testing; 45% were among reported MSM and an anorectal swab was performed in 40% of testing episodes. Anorectal swabbing had good diagnostic performance as a marker for MSM status (sensitivity = 87%, specificity = 99%, positive predictive value = 98·6%, negative predictive value = 90·3%). The model showed good fit against the internal validation sample (area under the curve = 0·93). Anorectal swabs are a valid marker of MSM behaviour in surveillance data from sexual health clinics, and they are likely to be particularly useful for monitoring STI trends among MSM with higher risk behaviour.

SUMMARYRepeat rectal chlamydia infection is common in men who have sex with men (MSM) following treatment with 1 g azithromycin. This study describes the association between organism load and repeat rectal chlamydia infection, genovar distribution, and efficacy of azithromycin in asymptomatic MSM. Stored rectal chlamydia-positive samples from MSM were analysed for organism load and genotyped to assist differentiation between reinfection and treatment failure. Included men had follow-up tests within 100 days of index infection. Lymphogranuloma venereum and proctitis diagnosed symptomatically were excluded. Factors associated with repeat infection, treatment failure and reinfection were investigated. In total, 227 MSM were included – 64 with repeat infections [28·2%, 95% confidence interval (CI) 22·4–34·5]. Repeat positivity was associated with increased pre-treatment organism load [odds ratio (OR) 1·7, 95% CI 1·4–2·2]. Of 64 repeat infections, 29 (12·8%, 95% CI 8·7–17·8) were treatment failures and 35 (15·4%, 95% CI 11·0–20·8) were reinfections, 11 (17·2%, 95% CI 8·9–28·7) of which were definite reinfections. Treatment failure and reinfection were both associated with increased load (OR 2·0, 95% CI 1·4–2·7 and 1·6, 95% CI 1·2–2·2, respectively). The most prevalent genovars were G, D and J. Treatment efficacy for 1 g azithromycin was 83·6% (95% CI 77·2–88·8). Repeat positivity was associated with high pre-treatment organism load. Randomized controlled trials are urgently needed to evaluate azithromycin's efficacy and whether extended doses can overcome rectal infections with high organism load.

SUMMARYChlamydiae are frequently encountered intracellular Gram-negative bacteria. In pigs, these bacteria in combination with other pathogens contribute to the induction of a multi-aetiological syndrome. One of the major characteristics of Chlamydia spp. is their ability to cause prolonged, often subclinical infections. While the economic consequences of Chlamydia spp. infections in pig farms are not fully established, we know that reproductive disorders and other syndromes correlated with Chlamydia infection can lead to financial loss as a result of a reduction in pork production. Additionally, Chlamydia spp. presents a potential zoonotic hazard, therefore determining the prevalence of Chlamydia in pig populations is critical. In the present study 97 pig herds from Poland were involved. To determine the prevalence of Chlamydia PCR and CFT tests were used. In total 797 vaginal samples, 797 conjunctival samples, and 235 serum samples were collected and tested. The study took place from 2011 to 2014. We found Chlamydia spp. present in 71·2% of all tested farms. The percentage of animals testing positive on any given farm varied from 20% to 100%.

SUMMARYParrots are one of the most popular pet birds in China, and can harbour Chlamydia which has significance for human and animal health. We investigated, by indirect haemagglutination assay, the seroprevalence of Chlamydia infection in four species of parrots, namely budgerigars (Melopsittacus undulatus), lovebirds (Agapornis sp.), cockatiels (Nymphicus hollandicus) and Alexandrine parakeets (Psittacula eupatria) that were collected from Weifang and Beijing cities, North China and explored the association between potential risk factors and chlamydial seropositivity. We further determined the genotype of Chlamydia in 21 fresh faecal samples based on the ompA sequence by reconstruction of phylogenetic relationships. Of the 311 parrots examined, 35·37% (95% confidence interval 30·06–40·68) were seropositive, and species, gender, age, season and geographical location were identified as risk factors. Two PCR-positive samples represented Chlamydia psittaci genotype A. The occurrence of C. psittaci genotype A in the droppings of two pet parrots in China suggests potential environmental contamination with Chlamydiaceae and may raise a public health concern.

SUMMARYThis study examined the prevalence of HIV and other sexually transmitted infections (STIs) in pregnant women in Kinshasa, the Democratic Republic of the Congo (DRC). Between April and July 2004, antenatal attendees at two of the largest maternity clinics in Kinshasa were tested to identify HIV status, syphilis, Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG). HIV seroprevalence was 1·9% in 2082 women. With PCR techniques, CT and NG infections were also uncommon in the first 529 women (1·7% and 0·4%, respectively). No active syphilis infection case was identified by Treponema pallidum haemagglutination assay (TPHA) and rapid plasma reagin test (RPR). A woman's risk of HIV infection was significantly associated with her reporting a male partner having had other female sexual partners (OR 2·7, 95% CI 1·2–6·2). The continuing low seroprevalence of HIV in pregnant women from Kinshasa was confirmed. Understanding factors associated with this phenomenon could help prevent a future HIV epidemic in low HIV transmission areas in Africa.