Chlamydia pneumoniae (CP) is a respiratory pathogen commonly associated with infections like pneumonia and bronchitis. However, accumulating evidence suggests that CP may also play a role in chronic inflammatory conditions and is implicated in certain cancers. Studies have detected CP DNA in various tumors, including lung cancer, hinting at its possible involvement in carcinogenesis. The exact mechanism by which CP may contribute to cancer remains unclear, but chronic infection could induce persistent inflammation, promoting cellular damage and malignancy. Epidemiological studies indicate that patients with chronic respiratory infections have an increased risk of lung cancer, especially when combined with risk factors such as smoking. This study aimed to evaluate the association between CP infection and lung cancer among Moroccan patients compared to a healthy control group, using molecular detection methods to assess the prevalence of CP DNA. Our findings showed that CP DNA was present in 33.3% of lung cancer patients and 4.7% of healthy controls, demonstrating a statistically significant difference in infection rates between cases and controls (p < 0.05). This aligns with previous studies reporting a higher prevalence of CP in cancerous tissues compared to healthy tissue, supporting a possible link between CP infection and lung carcinogenesis. Additionally, data analysis revealed that smoking and alcohol use were significantly more common among lung cancer patients than in controls (p < 0.05). Our results reinforce the hypothesis that tobacco use, together with CP infection, may amplify the risk of lung cancer. 

In conclusion, this study suggests a significant association between CP infection and lung cancer risk in the Moroccan population, with tobacco use potentially acting as a co-factor. These results are consistent with previous studies indicating that chronic bacterial infections, particularly in the presence of additional risk factors such as smoking, may contribute to cancer development. The findings highlight the need for further investigation into the role of infectious agents in lung cancer etiology and suggest that preventing CP infection, particularly in high-risk populations, could have implications for lung cancer prevention.