Microbiology and Immunology

Sexually transmitted diseases (STDs) WORLD OF MICROBIOLOGY AND IMMUNOLOGY

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help to avoid pre-transplant chemotherapyoften necessary to

prevent rejection of the marrow in older children. This is espe-

cially advantageous because chemotherapy can leave the

patient even more susceptible to invading bodies. When suc-

cessful, treatment for SCID corrects the patient’s immune sys-

tem defect, and as of 2002 success rates have been shown to

be nearly 80% for the bone marrow transplant.

Genetherapy is the subject of ongoing research, and

shows promise as a treatment for SCID. Researchers remove

T cells of SCID patients and expose those cells to the ADA

gene for ten days, and then return the cells intravenously.

Although it was successful in one case, this treatment of SCID

is still very much in the experimental stage. Nevertheless,

these and other treatments hold potential for the development

of a cure for SCID.

See alsoImmune system; Immunochemistry; Immunodefi-

ciency disease syndromes; Immunodeficiency diseases;

Immunogenetics; Immunoglobulins and immunoglobulin defi-

ciency syndromes; Immunological analysis techniques;

Immunology

SEXUALLY TRANSMITTED DISEASES

(STDSexually transmitted diseases (STDs)S)

Sexually transmitted diseases (STDs) vary in their susceptibil-

ity to treatment, their signs and symptoms, and the conse-

quences if they are left untreated. Some are caused by

bacteria. These usually can be treated and cured. Others are

caused by virusesand can typically be treated but not cured.

As of June 2002, recent advancements in diagnosis now allow

the identification of more than 15 million new cases of STD in

the United States each year.

Long known as venereal disease, after Venus, the

Roman goddess of love, sexually transmitted diseases are

increasingly common. The more than 20 known sexually

transmitted diseases range from the life-threatening to painful

and unsightly. The life-threatening sexually transmitted dis-

eases include syphilis, which has been known for centuries,

some forms of hepatitis, and Acquired Immune Deficiency

Syndrome (AIDS), which was first identified in 1981.

Most sexually transmitted diseases can be treated suc-

cessfully, although untreated sexually transmitted diseases

remain a huge public healthproblem. Untreated sexually

transmitted diseases can cause everything from blindness to

infertility. While AIDS is the most widely publicized sexually

transmitted disease, others are more common. More than 13

million Americans of all backgrounds and economic levels

develop sexually transmitted diseases every year. Prevention

efforts focus on teaching the physical signs of sexually trans-

mitted diseases, instructing individuals on how to avoid expo-

sure, and emphasizing the need for regular check-ups.

The history of sexually transmitted disease is controver-

sial. Some historians argue that syphilis emerged as a new dis-

ease in the fifteenth century. Others cite Biblical and other

ancient texts as proof that syphilis and perhaps gonorrhea

were ancient as well as contemporary burdens. The dispute

can best be understood with some knowledge of the elusive

nature of gonorrhea and syphilis, called “the great imitator” by

the eminent physician William Osler (1849–1919).

No laboratory tests existed to diagnose gonorrhea and

syphilis until the late nineteenth and early twentieth centuries.

This means that early clinicians based their diagnosis exclu-

sively on symptoms, all of which could be present in other ill-

nesses. Symptoms of syphilis during the first two of its three

stages include chancre sores, skin rash, fever, fatigue,

headache, sore throat, and swollen glands. Likewise, many

other diseases have the potential to cause the dire conse-

quences of late-stage syphilis. These range from blindness to

mental illness to heart disease to death. Diagnosis of syphilis

before laboratory tests were developed was complicated by

the fact that most symptoms disappear during the third stage

of the disease.

Symptoms of gonorrhea may also be elusive, particu-

larly in women. Men have the most obvious symptoms, with

inflammationand discharge from the penis from two to ten

days after infection. Symptoms in women include a painful

sensation while urinating or abdominal pain. However, women

may be infected for months without showing any symptoms.

Untreated gonorrhea can cause infertility in women and blind-

ness in infants born to women with the disease.

The nonspecific nature of many symptoms linked to

syphilis and gonorrhea means that historical references to sex-

ually transmitted disease are open to different interpretations.

There is also evidence that sexually transmitted disease was

present in ancient China.

During the Renaissance, syphilis became a common and

deadly disease in Europe. It is unclear whether new, more dan-

gerous strains of syphilis were introduced or whether the

syphilis which emerged at that time was, indeed, a new illness.

Historians have proposed many arguments to explain the dra-

matic increase in syphilis during the era. One argument sug-

gests that Columbus and other explorers of the New World

carried syphilis back to Europe. In 1539, the Spanish physi-

cian Rodrigo Ruiz Diaz de Isla treated members of the crew of

Columbus for a peculiar disease marked by eruptions on the

skin. Other contemporary accounts tell of epidemics of

syphilis across Europe in 1495.

The abundance of syphilis during the Renaissance made

the disease a central element of the dynamic cultureof the

period. The poet John Donne (1572-1631) was one of many

thinkers of that era who saw sexually transmitted disease as a

consequence of man’s weakness. Shakespeare (1564-1616)

also wrote about syphilis, using it as a curse in some plays and

referring to the “tub of infamy,” a nickname for a common

medical treatment for syphilis. The treatment involved placing

syphilitic individuals in a tub where they received mercury

rubs. Mercury, which is now known to be a toxic chemical, did

not cure syphilis, but is thought to have helped relieve some

symptoms. Other treatments for syphilis included the induc-

tion of fever and the use of purgatives to flush the system.

The sculptor Benvenuto Cellini (1500–1571) is one of

many individuals who wrote about their own syphilis during

the era: “The French disease, for it was that, remained in me

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