Chlamydia trachomatis are microbes which are leading cause for sexually transmitted diseases. Route of transmission of infection is sexual. It can affect persons of any age or gender but it produces more symptoms in men, particularly young ones, probably because they engage more in indiscreet sexual activity. Initially, there is a painful urethral discharge, especially in the morning. This is associated with painful urination. As infection ascends, there is inflammation of the testes, epididymis and prostate. Urinary bladder can be infected due to contamination adding to the pain and discomfort. Anus and rectum can be infected independently in those indulging in anal sex. There may be painful large swellings in the inguinal region. In women, the infection is mostly silent and is diagnosed due to the complications. It can infect the uterine cervix leading to clear or whitish yellow painless discharge. From here, infection can spread upwards and around causing pelvic inflammatory disease. Because of this, the patient can suffer from chronic low back pain, lower abdominal pain with or without discharge. After menses women are more prone to these infections as blood provides a rich media for germs to grow. Fallopian tubes can get infected causing severe pain in lower abdomen. They may get blocked, increasing risk of ectopic pregnancy and even sterility. Another risk of untreated infection is that the individual suffers from conjunctivitis causing redness and mucopurulent discharge from eyes, multiple joint swelling and pain and flat dry rashes over palms and soles. Eyes can also be infected directly when touched with contaminated hands. Mother-to-child Children suffer from Chlamydia infections for no fault of theirs. After being contaminated during delivery, a newborn may develop infection of the eyes, which can lead to blindness. An older infant can also suffer from infection of the eyes due to his eyes being touched by the contaminated finger of either parent. A newborn is also at the risk of having pneumonia after birth due to infection acquired from the mother’s birth canal. Considering the risks to the baby, Centre for Disease Control and Prevention recommends that even with a doubt for Chlamydia infection, treatment should be initiated immediately. People infected with Chlamydia are at a high risk of acquiring HIV. Diagnosis is established by isolating the infectious agents from swabs obtained from the genital secretions or lymph nodes and culture. It has to be differentiated from gonorrhea, another STD with similar symptoms. Treatment is by suitable antibiotic given minimum for a week. Ideally, both partners have to be treated simultaneously to prevent re introduction of infection. But treatment given once does not protect from re-infection. To prevent recurrence of infection, a person has to become disciplined in sexual activity and should stick to one partner for life. Condoms must be used correctly in order to prevent exposure to Chlamydia infection. Dr Rachna Pande is a specialist internal medicine at Ruhengeri Hospital