Chlamydia are interesting little bacteria. Yes, all bacteria are small by our standards, but when it comes to chlamydia they are really small and their size resembles a virus more than a bacterium. Often associated with sexually transmitted diseases, chlamydia are also responsible for other damage – to the eyes and the respiratory system… What distinguishes chlamydia from other bacteria? They definitely belong to bacteria and there is no dispute about that. Their small size is not enough to be classified as a virus. The curious thing about chlamydial cells is that they are energy parasites – like viruses, they do not have a system for their own energy production, but use that of the cell they parasitize. Their life cycle is also unusual – they have two forms – elementary and reticular bodies. Elementary bodies are their infectious form – like spores, they are highly resistant to adverse conditions. Once inside the host cell, they transform into reticular bodies. The latter are the growth form of chlamydia, and one divides into 100 to 1000 elementary bodies, ready to infect neighboring cells. These bacteria predominantly affect the epithelial cells of the mucous membranes, which also determines the diseases they cause – conjunctivitis, urogenital infections and pneumonia. 3 types of chlamydia are pathogenic for humans – Chlamydia trachomatis – affects the eyes, genitals and lungs, and Chl. psittaci and Chl. pneumoniae – lungs only. Chlamydia trachomatis has different serovars (subspecies), also responsible for different diseases. Trachoma This is a severe chronic disease that occurs with conjunctivitis and keratitis (inflammation of the cornea). Chlamydia is currently the leading cause of preventable blindness globally. It is transmitted from person to person, the main source being children between 3 and 10 years of age. It is spread due to poor personal hygiene and flies also contribute. A single infection in children usually passes as acute conjunctivitis. Blindness occurs mainly in elderly patients. It is believed that frequent reinfections with the causative agent are responsible for it. The disease begins unnoticed and almost without complaints. Damage to the conjunctiva is expressed in the appearance of follicles (small yellowish grains) under the upper eyelid. Over time, the surface of the conjunctiva becomes more uneven, and the follicles grow, fuse and burst. In their place, cicatrixes (scars) appear. The process also covers the cornea, which becomes swollen, blood vessels appear there (where normally there are none) and this worsens vision. This occurs slowly over years and is further aggravated by complications: Impairment of the eye’s cleansing mechanisms predisposes it to secondary bacterial infections; Adhesion of the mucous membrane covering the eyelid with that,covering the eyeball (symblepharon); Cicatrixes damage the hair follicles of the eyelashes and they may begin to grow inward or fall out; Corneal ulcers. NEWS_MORE_BOX Treatment is possible and affordable – local drops and ointments, possibly – and systemic antibiotics. Individual use of towels, pillows and personal hygiene are sufficient to prevent the disease. Chlamydial pneumonia Chl. Pneumonia causes primary atypical pneumonia – of those called community-acquired. It mainly affects the young and the elderly, children – rarely. Most infections are subclinical – asymptomatic. Therefore, asymptomatic carriers are a major reservoir. This, together with the long incubation period – 3 weeks, does not allow the patient to know where he “acquired” the disease. Characteristic of the disease is the biphasic course – it starts with affecting the upper respiratory tract (rhinitis, pharyngitis, sinusitis) and after 1 to 4 weeks pneumonia develops. It presents with cough, sputum discharge, high fever and severe general malaise. Studies indicate that suffering from this pneumonia may be associated with the development of pulmonary asthma in adults. The diagnosis is clinical and laboratory. Treatment may seem like a slight challenge to the patient, since chlamydia is not the first thing that comes to mind. With a successful diagnosis, antibiotics last for an average of 3 weeks until healing, but the cough can be present for a long time after that.