**1. Introduction**

More than 1 million sexually transmitted infections are acquired every day worldwide and chlamydial infection is the most common in the developed world, showing no decreasing trends in the incidence the last years [1]. As a result, chlamydial infection presents a major burden of disease that impacts negatively people's sexual and reproductive health and may result in adverse perinatal outcomes. As chlamydiae are largely asymptomatic and high rates of antibiotic resistance [2] have been shown, screening and treatment are the most crucial issues to reduce their impact globally.

Chlamydial infection can be transmitted to the infant during childbirth, resulting in conjunctivitis or pneumonia as a clinical disease. If present beyond the neonatal period in a child, may be a sign of sexual abuse. Sexually transmitted infection can occur in sexually active adolescents leading to a cascade of potentially serious inflammatory-induced sequelae.
