However, this specialized connotation of the word "contagious" and "contagious disease" (easy transmissibility) is not always respected in popular use. Infectious diseases are commonly transmitted from person to person through direct contact. The types of contact are through person to person and droplet spread. Indirect contact such as airborne transmission, contaminated objects, food and drinking water, animal person contact, animal reservoirs, insect bites, and environmental reservoirs  are another way infectious diseases are transmitted. By anatomic location
Infections can be classified by the anatomic location or organ system infected, including:
Urinary tract infection
Skin infection
Respiratory tract infection
Odontogenic infection (an infection that originates within a tooth or in the closely surrounding tissues)
Vaginal infections
Intra-amniotic infectionIn addition, locations of inflammation where infection is the most common cause include pneumonia, meningitis and salpingitis. Prevention
Techniques like hand washing, wearing gowns, and wearing face masks can help prevent infections from being passed from one person to another. Aseptic technique was introduced in medicine and surgery in the late 19th century and greatly reduced the incidence of infections caused by surgery. Frequent hand washing remains the most important defense against the spread of unwanted organisms. There are other forms of prevention such as avoiding the use of illicit drugs, using a condom, wearing gloves, and having a healthy lifestyle with a balanced diet and regular exercise. Cooking foods well and avoiding foods that have been left outside for a long time is also important. Antimicrobial substances used to prevent transmission of infections include:

antiseptics, which are applied to living tissue/skin
disinfectants, which destroy microorganisms found on non-living objects.
Nevertheless, the failure to irrefutably demonstrate infectivity following intracerebral inoculation with urine from transmissible spongiform encephalopathy (TSE)-infected hosts suggests that the risk associated with products derived from urine is merely theoretical.Recombinant gonadotropins have to a large degree replaced hMG in fertility treatments. The recombinant process allows for the production of pure FSH or LH not "contaminated" by other proteins that may be present after urinary extraction. While some head-on studies seem not to suggest that "pure FSH" gives better results than hMG, others claim that recombinant FSH is more efficient and reduces costs. A Cochrane Collaboration analysis did not reveal major differences in clinical outcomes when comparing urinary versus recombinant FSH.The Practice Committee of the American Society for Reproductive Medicine reported: “Compared with earlier crude animal extracts, modern highly purified urinary and recombinant gonadotropin products have clearly superior quality, specific activity, and performance.