This is a good the birth of the museum history theory politics pdf. Follow the link for more information. This article is about the transmission barrier and contraceptive device.
Male condoms have the advantages of ease of use, easy to access, and few side effects. Female condoms are typically made from polyurethane and may be used multiple times. Condoms as a method of preventing STIs have been used since at least 1564. Rubber condoms become available in 1855, followed by latex condoms in the 1920s. In the United States condoms usually cost less than 1. About six to nine billion are sold a year. Rates are generally presented for the first year of use.
They have been shown to be effective in reducing infection rates in both men and women. STD protection is also desired. 9 per 100 person-years with condom, down from 6. Although a condom is effective in limiting exposure, some disease transmission may occur even with a condom. Infectious areas of the genitals, especially when symptoms are present, may not be covered by a condom, and as a result, some diseases like HPV and herpes may be transmitted by direct contact. The primary effectiveness issue with using condoms to prevent STDs, however, is inconsistent use. Exposure to human papillomavirus, even in individuals already infected with the virus, appears to increase the risk of precancerous changes.
The use of condoms helps promote regression of these changes. In addition, researchers in the UK suggest that a hormone in semen can aggravate existing cervical cancer, condom use during sex can prevent exposure to the hormone. The rate of breakage is between 0. Double bagging”, using two condoms at once, is often believed to cause a higher rate of failure due to the friction of rubber on rubber. This claim is not supported by research. The limited studies that have been done found that the simultaneous use of multiple condoms decreases the risk of condom breakage.