Blood testing

Blood testing is commonly used to detect or “screen for” a wide variety of diseases either present or potential. It is used both in health care settings and in the criminal justice system. When blood tests are used for DNA typing as the basis for constructing databases used in criminal investigations, or for detecting behaviors such as substance use, they obviously raise privacy issues similar to those raised by urine analysis to test for drugs of abuse. Unlike urine tests, blood tests can reveal a person’s current degree of intoxication. The approximate time of drug ingestion can by ascertained by computing the ratio of drug metabolites in the blood to the presence of the drug itself. For these reasons many states permit law enforcement to draw blood in cases of suspected driving under the influence (DUI) if the individual under suspicion refuses to submit to urine testing or a breathalyzer test. In Schmerber v. California, 384 U.S. 757 (1966), a case involving a police officer who ordered a treating physician to conduct a test for blood alcohol level, the U.S. Supreme Court held that the blood testing did not violate the Fifth Amendment guarantee against self-incrimination even if results were later used as evidence in a drunk driving conviction. Subsequently the courts have considered blood tests to be legal searches, although any state-compelled blood testing program raises privacy issues due to the Fourth Amendment’s clear guarantee against government intrusion.
Public health and safety objectives have occasioned large-scale government intrusions into private life. The “greater good” argument is often invoked to justify the claim that social responsibility outweighs individual privacy rights in the context of infectious diseases and viral transmission. Syphilis was once a widely feared disease for which there was a relatively accurate and simple blood test. Although gonorrhea was four times as prevalent in the population, there was no straightforward blood test by which it could be diagnosed. The first mass blood testing campaign in the United States occurred within the context of the New Deal, with the launch of a federal public health campaign to contain venereal disease that focused on syphilis. The U.S. Public Health Service began to devote a significant portion of the budget allocated to it by the Social Security Act of 1935 to detecting and treating venereal disease. The U.S. Congress enacted the National Venereal Disease Control Act in 1938, which led to a national infrastructure consisting of 3000 treatment clinics as of 1940. (These clinics were later converted to family planning clinics once the concern about VD had subsided.)
The blood testing campaign against syphilis was conducted in an era when privacy and confidentiality were not legally protected. The number of Wasserman blood tests administered for detecting syphilis climbed nearly 300 percent from 1936 to 1940. The city of Chicago tested over 30 percent of its population beginning in 1937, capturing 10,000 to 12,000 individuals a day in its “Wasserman dragnet.” Although these programs likely produced a high number of false positives, the results were used in many cases to deny or delay marriage. Over half of the states had enacted laws prohibiting marriage between infected individuals by 1938.
States also began requiring prenatal blood testing for all pregnant women in 1938 to prevent congenital infection of infants. These laws resulted in reduced infant mortality rates even prior to the use of antibiotics. They also occasioned a large-scale expansion of government surveillance into formerly private matters. Public health organizations invented techniques to extract information about all sexual contacts from those who tested positive for syphilis. Case workers invented a term, “shoe leather epidemiology,” to describe how they tracked down those individuals to inform them and bring them in for testing and treatment.
Premarital syphilis testing was instituted by the states, beginning with Connecticut in 1935, but prevalence rates were lower than anticipated. Couples crossed state lines to marry, or they went to physicians reputed to keep the test results confidential. Despite the ineffectiveness of these laws, as evidenced by the low percentage of positive results, many states did not repeal them until the 1970s. A second wave of repeal followed in states where such laws were still on the topics: California did not repeal its premarital blood testing law until 1994, and Georgia only did so as recently as 2003. Reasons for repeal included lack of cost-effectiveness and the fact that few cases of syphilis came to light through premarital testing, due to its higher prevalence among groups not seeking to marry or who were legally barred from marriage. The initial assumption behind premarital blood testing was that it would reach the affected population and bring those who tested positive in for treatment. However, this proved not to be the case, and it constitutes a historical lesson that can be extended to human immunodeficiency virus (HIV) testing. The concern is that mandatory testing will in fact deter individuals from seeking treatment.
Blood banks began testing for HIV in 1985 using an initial screen for the presence of HIV antibodies called an enzyme-linked immunosorbent assay (ELISA). A positive screen must be followed by a Western blot, which is a confirmatory test. Blood banks did not, however, notify individuals of their serostatus, as their main goal was to ensure that the blood supply was not infected. The main focus of the debate over state-compelled HIV testing has been mandatory testing. Given the stigma attached to HIV, which was initially seen as a phenomenon associated with the gay population in the United States, there has been much more scrutiny of state-mandated HIV testing than there was for syphilis testing. The drive to require premarital HIV testing was unsuccessful in the United States: only two states, Illinois and Louisiana, enacted mandatory premarital HIV testing laws, and each has since repealed them. Given the higher rates of heterosexual HIV transmission in the Third World, some governments in south and southeast Asia began to require mandatory premarital HIV testing in the opening years of the twenty-first century.
Mandatory HIV testing has been upheld by the U.S. courts for certain groups. The U.S. Congress passed the Comprehensive Crime Control Act (1990), encouraging states to provide mandatory HIV testing of sex offenders and to make their serostatus known to their victims. Newborns are a second group in which mandatory testing has been permitted. New York and Connecticut both require expedited HIV testing of newborns and notification of their mothers when the serostatus of the mother is unknown. Prenatal HIV testing remains voluntary. Both circumstances in which mandatory HIV testing is applied also involve privacy issues that the U.S. Supreme Court has not yet considered, although it has ruled that the “special needs” exception to the Fourth Amendment applies to compulsory urine testing of certain populations of workers. Urine tests were considered “reasonable” infringements on the privacy of groups associated with “diminished expectation of privacy” in National Treasury Employees Union v. Von Raab, 489 U.S. 669 (1989). Similar exceptions may extend to mandatory government blood testing and DNA testing. The privacy question involved in the mandatory collection of blood samples for DNA testing is the extent to which prisoners forfeit their Fourth Amendment rights. Some courts have interpreted this forfeiture expansively, others more restrictively.
Another privacy question concerns disclosures of information that includes the results of blood testing. The U.S. Congress passed the Genetic Information Nondiscrimination Act of 2003 (S. 1053) in an attempt to prevent genetic discrimination in hiring, firing, and training, as well as insurance discrimination on the basis of results of genetic testing. The concern with maintaining the confidentiality of medical records extends to genetic test results. There are many more mechanisms for protecting individual privacy and guaranteeing the confidentiality of blood test results today. Built-in exceptions to the privacy rules of the Health Insurance Portability and Accountability Act of 1996 (HIPAA) allow disclosure of certain kinds of information to public health authorities, such as history of disease or injury, child abuse, birth, death, and the conduct of public health surveillance, investigation, or intervention programs.