Inflammation of the cervix, one of the most frequently occurring gynaecological conditions, roughly 50 per cent of women suffer from it at some time, and it almost always occurs in childbirth. Use of the contraceptive pill, pessaries or intra-uterine devices (coils) slightly increases the probability of the disorder. It can be caused by fungi (candidiasis), bacteria or viruses, and the most usual symptoms are vaginal discharge and itching. When the cervical mucus is affected the white blood cells contain a factor which make it impenetrable for sperm, thus causing temporary infertility. Treatment of cervicitis and thorough checking are important; smear tests and cultures can be of use. An infectious disease transmitted by insects and caused by a protozoan parasite (Trypanosoma cruzi). It occurs principally in South and Central America, where about 10 million people are infected. The trypanosomes are very small and move by means of a flagellum through the human circulatory system. Blood-sucking insects suck up blood containing trypanosomes and deposit them on the skin of other human beings in their excrement while sucking blood. The insects are intermediate hosts (vectors). The trypanosomes develop in heart muscle among other places. Initially this has few consequences, but after years it can suddenly lead to serious inflammation of the heart muscle, often resulting in death. The trypanosomes can also develop in the brain, with meningitis as a possible consequence together with disturbance in the regulation of other brain functions, such as sleep. Many children die as a result of this. Treatment by medication is possible only in the early stages. If untreated the disease is often fatal after a few years. Small, firm, painless swelling in the upper or lower eyelid. The skin moves freely over the swelling. A small blob is visible on the inside of the eyelid some distance from the edge, without signs of inflammation such as redness or accumulation of fluid. Chalazion results from blockage of a sebaceous gland; the sebaceous glands have a large number of exits in the upper and lower eyelids just below the roots of the eyelashes. If a chalazion causes discomfort – to contact lens wearers for example – it can be removed by an ophthalmic surgeon making a small incision inside the eyelid. If no discomfort is caused no treatment is necessary.