San FranciscoCaliforniaBays: An area of water mostly surrounded by land, usually smaller than a gulf, and affording access to the sea.Homeless Persons: Persons who have no permanent residence. The concept excludes nomadic peoples.Estuaries: A partially enclosed body of water, and its surrounding coastal habitats, where saltwater from the ocean mixes with fresh water from rivers or streams. The resulting mixture of seawater and fresh water is called brackish water and its salinity can range from 0.5 to 35 ppt. (accessed http://oceanservice.noaa.gov/education/kits/estuaries/estuaries01_whatis.html)Homosexuality: The sexual attraction or relationship between members of the same SEX.Substance Abuse, Intravenous: Abuse, overuse, or misuse of a substance by its injection into a vein.Homosexuality, Male: Sexual attraction or relationship between males.HIV Infections: Includes the spectrum of human immunodeficiency virus infections that range from asymptomatic seropositivity, thru AIDS-related complex (ARC), to acquired immunodeficiency syndrome (AIDS).Sexual Behavior: Sexual activities of humans.Asian Americans: Persons living in the United States having origins in any of the original peoples of the Far East, Southeast Asia, or the Indian subcontinent.Hispanic Americans: Persons living in the United States of Mexican (MEXICAN AMERICANS), Puerto Rican, Cuban, Central or South American, or other Spanish culture or origin. The concept does not include Brazilian Americans or Portuguese Americans.Risk Factors: An aspect of personal behavior or lifestyle, environmental exposure, or inborn or inherited characteristic, which, on the basis of epidemiologic evidence, is known to be associated with a health-related condition considered important to prevent.Skin Manifestations: Dermatologic disorders attendant upon non-dermatologic disease or injury.Opium: The air-dried exudate from the unripe seed capsule of the opium poppy, Papaver somniferum, or its variant, P. album. It contains a number of alkaloids, but only a few - MORPHINE; CODEINE; and PAPAVERINE - have clinical significance. Opium has been used as an analgesic, antitussive, antidiarrheal, and antispasmodic.Acquired Immunodeficiency Syndrome: An acquired defect of cellular immunity associated with infection by the human immunodeficiency virus (HIV), a CD4-positive T-lymphocyte count under 200 cells/microliter or less than 14% of total lymphocytes, and increased susceptibility to opportunistic infections and malignant neoplasms. Clinical manifestations also include emaciation (wasting) and dementia. These elements reflect criteria for AIDS as defined by the CDC in 1993.Sexually Transmitted Diseases, Bacterial: Bacterial diseases transmitted or propagated by sexual conduct.Risk-Taking: Undertaking a task involving a challenge for achievement or a desirable goal in which there is a lack of certainty or a fear of failure. It may also include the exhibiting of certain behaviors whose outcomes may present a risk to the individual or to those associated with him or her.Bisexuality: The sexual attraction or relationship between members of both the same and the opposite SEX.Deodorants: Agents that remove, correct, repress, or mask undesirable ODORS. In personal hygiene, deodorants often contain astringent preparations that reduce SWEATING, referred to as ANTIPERSPIRANTS. (From Grant & Hackh's Chemical Dictionary, 5th ed)City Planning: Comprehensive planning for the physical development of the city.HIV Seropositivity: Development of neutralizing antibodies in individuals who have been exposed to the human immunodeficiency virus (HIV/HTLV-III/LAV).Needle-Exchange Programs: Organized services for exchange of sterile needles and syringes used for injections as a potential means of reducing the transmission of infectious diseases.Drug Overdose: Accidental or deliberate use of a medication or street drug in excess of normal dosage.Medical Indigency: The condition in which individuals are financially unable to access adequate medical care without depriving themselves and their dependents of food, clothing, shelter, and other essentials of living.Gonorrhea: Acute infectious disease characterized by primary invasion of the urogenital tract. The etiologic agent, NEISSERIA GONORRHOEAE, was isolated by Neisser in 1879.African Americans: Persons living in the United States having origins in any of the black groups of Africa.Bread: Baked food product made of flour or meal that is moistened, kneaded, and sometimes fermented. A major food since prehistoric times, it has been made in various forms using a variety of ingredients and methods.Population Surveillance: Ongoing scrutiny of a population (general population, study population, target population, etc.), generally using methods distinguished by their practicability, uniformity, and frequently their rapidity, rather than by complete accuracy.Contraceptive Devices, Male: Contraceptive devices used by males.Methamphetamine: A central nervous system stimulant and sympathomimetic with actions and uses similar to DEXTROAMPHETAMINE. The smokable form is a drug of abuse and is referred to as crank, crystal, crystal meth, ice, and speed.United StatesHIV Seroprevalence: Studies of the number of cases where human immunodeficiency virus (HIV) is present in a specific population at a designated time. The presence in a given individual is determined by the finding of HIV antibodies in the serum (HIV SEROPOSITIVITY).Housing: Living facilities for humans.Haplosporida: A phylum of EUKARYOTES in the RHIZARIA group. They are small endoparasites of marine invertebrates. Spores are structurally complex but without polar filaments or tubes.Logistic Models: Statistical models which describe the relationship between a qualitative dependent variable (that is, one which can take only certain discrete values, such as the presence or absence of a disease) and an independent variable. A common application is in epidemiology for estimating an individual's risk (probability of a disease) as a function of a given risk factor.Case-Control Studies: Studies which start with the identification of persons with a disease of interest and a control (comparison, referent) group without the disease. The relationship of an attribute to the disease is examined by comparing diseased and non-diseased persons with regard to the frequency or levels of the attribute in each group.Urban Population: The inhabitants of a city or town, including metropolitan areas and suburban areas.Sexual Partners: Married or single individuals who share sexual relations.PrisonersSyringes: Instruments used for injecting or withdrawing fluids. (Stedman, 25th ed)Ethnic Groups: A group of people with a common cultural heritage that sets them apart from others in a variety of social relationships.Heroin: A narcotic analgesic that may be habit-forming. It is a controlled substance (opium derivative) listed in the U.S. Code of Federal Regulations, Title 21 Parts 329.1, 1308.11 (1987). Sale is forbidden in the United States by Federal statute. (Merck Index, 11th ed)