Are Rectal and Genital Chlamydia Trachomatis Infections in Women Related to Anal Sex, Autoinoculation / Contamination
试验速览
- 阶段
- 不适用
- 入组人数
- 600
- 试验地点
- 2
- 主要终点
- Incidence of true rectal chlamydial infections in women not practicing anal sex. Is there statistically significant difference between those that practice fellatio or not and those that have received sperma orally or not?
研究概览
简要总结
Chlamydia trachomatis is the most common cause of sexually transmitted bacterial infection in Sweden, an infection that is notifiable according to the Communicable Diseases Act and the Communicable Diseases Ordinance.
Women account for 57 % of all cases detected since 1993. Recently published studies describe a high proportion of positive rectal chlamydia tests in women and in half of the cases there is no history of anal sex. In almost 20 % of cases, chlamydia has only been found rectally. Samples in these studies were self-collected and although the sensitivity of modern NAATs (Nucleic Acid Amplification Tests) is very high, there is even high risk of contamination of the sample due to the short anatomical distance between the vagina and the anus. Furthermore the vaginal sample has been taken prior to the rectal sample in the largest study from the Netherlands, something that further increases the risk of contamination of the rectal sample.
There are experimental animal models which support the theory that chlamydia can be transferred along the gastrointestinal tract! This is a possible explanation for the occurrence of rectal chlamydia in women who have not had anal intercourse, but it is necessary to minimize the risk of contamination.
The study will take part in three STD-clinics (2 counties) where two clinics are in the county of Östergötland (Norrköping and Linköping with totally 300 000 inhabitants) and one in the county of Jönköping (120 000 inhabitants).
The risk of contamination of the rectal samples is minimized as the rectal sample is taken first and with the use of a pediatric proctoscope (a proctoscope that is designed to examine children) which is first inserted in the anus to allow sample collection from the rectal mucosa above the pectinate line, while avoiding contact of the collecting swab with the perineal skin. Then vaginal speculum examination is performed and samples are taken from endocervix and vagina for C.trachomatis N.gonorrhoeae and M.genitalium tests. Extra samples from the anus and the vagina will be collected and immediately frozen to minus 80 degrees to allow further testing with vPCR (viability Polymerase Chain Reaction). Positive chlamydia samples will be further analyzed with a high resolution method (Multi Locus Sequence Typing, or MLST and if necessary Multi-Locus Variable number tandem repeat Analysis or MLVA) to make the discrimination of various chlamydia types possible.
详细描述
In the county of Östergötland.
Both STD (Sexually Transmitted Diseases) outpatient clinics in Östergötland belong to the Department of Dermatology and Venereology in Region Östergötland. The attendee has two options: either makes an appointment to a physician if the attendee has symptoms or wishes a gynecological exam because of other reasons, or make an appointment to a nurse for self-collecting tests.
All attendees answer a questionnaire including experience of receptive anal sex and fellatio (and condom use) during the last 12 months. In the study questionnaire there is an additional question regarding fellatio and whether it happened that a male partner ejaculated in her oral cavity.
At the visit by the physician:
The exam starts with an Abbot multi-collect swab taken from the anal verge, at the opening of the anal canal, where the inverstigators think the most self-taken samples come from. This sample will be immediately frozen for later analysis.
研究设计
- 研究类型
- Observational
- 观察模型
- Case Crossover
- 时间视角
- Cross Sectional
入排标准
- 年龄范围
- 18 Years 至 —（Adult, Older Adult）
- 性别
- Female
- 接受健康志愿者
- 是
入选标准
- •All attendees at the STD clinic in the county of Östergötland
- •Attendees with a verified chlamydia infection of their current partner in the county of Jönköping.
排除标准
- •Younger than 18 years old.
- •Severe rectal disease, for example, active inflammatory bowel disease or rectal cancer.
- •Incapability to fill the questionnaire and / or understand the meaning / character of the study (eg women with language difficulties in Swedish, or mental development disorders)
结局指标
主要结局
Incidence of true rectal chlamydial infections in women not practicing anal sex. Is there statistically significant difference between those that practice fellatio or not and those that have received sperma orally or not?
时间窗: 2 years
Among participants with positive rectal chlamydial tests there will exist a subgroup not practicing anal sex according to the results of previous studies. If the theory of orogastrointestinal proliferation is possible in humans, then among those women there should be a number practicing fellatio and the number of those receiving sperm orally could more often have a rectal infection.
Detection of chlamydial DNA in rectal and vaginal specimens in women attending the out-patient clinics of the county of Östergötland.
时间窗: 2 years
Detection of chlamydial DNA (NAAT) and verification of presence of viable bacteria (vPCR).Which percentage of all anogenital infections is rectal and only rectal?
Molecular typing of chlamydial DNA extracted from specimens from vaginal and rectal mucosa. Frequency of concordance or discordance between chlamydial types found in respective site.
时间窗: 2 years
Molecular typing (MLST and if needed MLVA) of chlamydial DNA in participants with simultaneous infection of the vagina and the rectum. Number of participants with simultaneous vaginal and rectal chlamydial infections with the same chlamydial type in both sites (concordance) vs number of participants with simultaneous vaginal and rectal chlamydial infections with different chlamydial type in vagina and rectum (discordance).
Chlamydia infection specificity of swabs taken without proctoscope vs swabs taken with pediatric proctoscope. Risk for false positive for swabs taken with and without pediatric proctoscope.
时间窗: 2 years
How many positive rectal chlamydia tests are verified as true infections with a positive vPCR and how many positive rectal chlamydia tests are a result of DNA contamination? Which is the true sensitivity of self-taken rectal tests and how often are self-taken tests false positive?
Grade of discomfort and willingness of participants to undergo rectal sampling with a pediatric proctoscope.
时间窗: 2 years
All participants will be asked to fill a standard questionnaire after the proctoscopy. The grade of discomfort will be assessed by each participant with the help of a Visual Analogue Scale (VAS), where the one end is equal to no discomfort and the other is equal to the worst discomfort experienced. The willingness of the participants to take the rectal tests the same way in the future if requested will be assessed by each participant again with the help of a Visual Analogue Scale, where then one end is equal to willing to take the rectal tests the same way again, while the other end equal to not willing. Both scales will consist of 100 mm long lines and the results will be measured according to the intervals of 0-4 mm (no discomfort/willing), 5-44 mm (mild discomfort/probably willing), 45-74 mm (moderate discomfort/probably not willing) and 75-100 mm (severe discomfort/ not willing).
次要结局
- Frequency of symptoms in patients with a rectal chlamydial infection.(2 years)
- Prevalence of non-specific cervicitis among participants with rectal chlamydial infections vs participants without rectal chlamydial infections.(2 years)
- Comparison of chlamydial bacterial loads measured in chlamydia copies per milliliter between rectal and vaginal specimens.(2 years)
研究者
Napoleon Kentarchos
Residence in Dermatology and Venereology the Department of Dermatology and Venereology in Region Östergötland
Region Östergötland