Table 3. Negative correlation between CT, HPV, and cervical cancer.

HPV: human papillomavirus; CT: Chlamydia trachomatis; HrHPV: high-risk human papillomavirus

Author	Year of publication	Study design	Population characteristics	Sample size	Outcome
Abu-Lubad et al. [28]	2020	Case-control study	Age: 20-80 years; multicenter, Jordan	144	A lack of coinfection was observed between HPV and CT in both cancer types
Sangpichai et al. [3]	2019	Cross-sectional study	Khon Kaen University, Thailand	150	CT infection was not significantly associated with hrHPV and abnormal cytology
Robial et al. [27]	2017	Cross-sectional study	Age: 18-64 years; cancer-screening project, Sao Paulo, Brazil	1,481	No association was found between abnormal cervical cytology and positive CT [OR: 1.21 (0.46-3.2)]
Smelov et al. [29]	2016	Case-control study	Age:16-89 years; Sweden	1,553	CT was not associated with increased risks of invasive adenocarcinoma or its precursor, adenocarcinoma in situ
Bhatla et al. [5]	2013	Cross-sectional study	Age:30-74 years; hospital in New Delhi, India	600	Subjects with positive hrHPV and CT showed no significant association with abnormal Pap smears, compared with hrHPV infection alone [p=0.210, OR: 0.3 (0.0-2.5)], or histopathology CIN2 or greater [p=0.341, OR: 0.342 (0.034-3.424)]
Calil et al. [30]	2011	Cross-sectional study	Primary care units in southern Brazil	86	The presence of CT infection does not seem to be associated with cervical carcinogenesis