Bio 311
Information for this section was taken from the URLs
indicated in each section and from the following books:
Alcamo, I.E. 2001. Fundamental of Microbiology. Jones
and Bartlett Publishers, Sudbury, MA.
Wistreich, G.A. 1992. The Sexually Transmitted Diseases: A Current Approach. Wm. C. Brown Publishers, Dubuque, IA.
Of the STDs that are diagnosed, only four are required to be reported to state health departments and the Centers for Disease Control (CDC) for statistical purposes. These are: Gonorrhea, Syphilis, Chlamydia and Hepatitis B. Of these, Hepatitis B is the only infection caused by a virus, the other diseases are caused by bacteria. Of the four, chlamydia is more prevalent in the US followed by Gonorrhea.
1. Bacteria are prokaryotes. Cellular organisms that do not have a nucleus.
2. Bacteria vary in size, but are about 5
times smaller that eukaryotic cells (nucleated cells making up the human,
animal and plant organisms).
3. Bacteria are about 10 times larger than
viruses.
4. Bacteria are characterized by having the
following structures:
a.
Nucleoid- Is
where the genomic circular DNA of the bacteria exists.
b.
Plasmid- Is
a small circular DNA that contain few genes, sometimes resistance genes.
c.
Flagella-they
propel the bacteria to different places.
d.
Pili-enable
attachment of bacteria to different surfaces also may allow transfer of genetic
material among bacteria.
e.
Glycocalix-It
is made of polysaccharides (sugars) and small proteins. If it is thick, it is known as a
capsule. If it is thin, it is
considered a slime layer. Serves
to buffer against environment and to attach to surfaces.
f.
Cell
membrane*
g.
Cell wall*
* Eukaryotes also have a cell membrane that carries out similar
functions, but in animal cells there is no cell wall. Plant cells are eukaryotic and have a cell wall, but the
chemical component of Plant cell walls is cellulose, the chemical component of
bacteria cell wall is peptidoglycan.
Bacteria can be Gram-Positive or Gram-Negative
·
Gram
Positive bacteria have a
Thick cell wall of peptidoglycan above the cell membrane.
·
Gram
Negative bacteria have a
thin cell wall of peptidoglycan above the cell membrane. In turn, an outer membrane surrounds
the thin cell wall.
· The Gram stain consists of using Crystal violet (CV) as primary staining, using iodine (I) as mordant fixation to form CV-I complex, distaining with alcohol and counterstaining with safranin to give Gram negative bacteria a pink color.
Bacterial Replication
Bacteria
replicate by binary fission.
Bacteria can replicate in as little as 20 minutes.
Bacteria can
have different shapes:
·
Rod
(bacillus, streptobacillus)
·
Sphere
(Coccus, diplococcus, staphylococcus, streptococcus)
·
Spiral
(Spirillum, Spirochete, Vibrio)
Table I. Sexually Transmitted Bacterial Diseases
Syphilis Treponema
pallidum Spirochete
Gonorrhea Neisseria
gonorrhoeae Gram negative
diplococcus
Chlamydia Chlamydia
trachomatis Chlamydia (coccus)
Ureaplasma
Urethritis Ureaplasma
urealyticum Mycoplasm (coccus)
Chancroid Haemophilus
ducreyi Gram-negative
rod
Lymphogranuloma
Venereum Chlamydia
trachomatis Chlamydia
Granuloma
Inguinale Calymmatobacterium
Granulomatis Gram-negative rod
Vaginitis Gardnerella
vaginalis Gram-negative
rod
Mycoplasmal
Urethritis Mycoplasma
hominis
Mycoplasma
genitalium Mycoplasma
http://www.ashastd.org/stdfaqs/syphilis.html
Medical historians have traced syphilis from Spain throughout
Europe and Asia. One commonly held
view is that syphilis was brought to Europe by Columbus and his crew after
their first voyage to the West Indies.
It is true that within a few years of Columbus’s return from his
first voyage to the New World, epidemics of the disease spread across Europe
with devastating effects. History
suggests that the Spaniards introduced the disease to the Italians while
fighting beside the troops of Alfonso II of Naples. Then, in 1495, an army of mercenaries fighting for Charles
VII of France conquered Naples. As
they returned home through France, Germany, Switzerland, Austria, and England,
they carried along the disease. By
1496, syphilis was so uncontrolled in Paris that strict laws were passed
banishing anyone with the disease from the city. In 1498, Vasco de Gama and his Portuguese crew carried
syphilis to India, and from there it spread to China. Outbreaks of syphilis in Japan soon followed the visits of
European ships.
Another view holds that syphilis arrived in Spain and Portugal
with slaves imported from Africa in the mid-1400s. Another bacterial disease found in Africa, called yawa,
which is quite similar to syphilis in several respects, is believed by certain
historians to have flared in the form of syphilis in the late 1400s. They further speculate that the army of
Charles VIII provided a highly susceptible population that spread the disease
wherever they went.
Physicians in the early sixteenth century did not have a name for the disease we now call syphilis. However, its obvious devastating effects throughout the years inspired a number of epithets. The Italians referred to it as the Spanish disease, while the French called it the Neapolitan disease. As syphilis spread to many countries, it acquired the name of the French sickness, a name that lasted for about a century.
The term syphilis was introduced by the Italian physician Girolamo
Fracastrorius, who wrote a poem about a shepherd boy named Syphilus. Apparently, Syphilus left a flock of
sheep belonging to the Greek god Apollo for some sexual activity. As punishment for leaving the sheep
unattended, he developed the horrible sores of the disease.
Syphilis was as international in effect as in name, and proved to
respect no rank. Henry VIII of
England, Napoleon of France, and Peter the Great of Russia all contracted the
disease. Poets such as Keats,
musicians such as Beethoven, and artists such as Gauguin also succumbed as did
millions of common people.
Syphilis is
caused by Treponema pallidum. The bacterium
spreads by human to human contact, usually during sexual intercourse. It
penetrates the skin surface through the mucous membranes or via a wound,
abrasion, or hair follicle.
·
Primary
syphilis is the first
stage to appear. This stage is
characterized by the chancre, a painless circular, purplish ulcer with a raised
margin and hard edges described as being like cartilage. The chancre develops at the site of
entry of the spirochetes, often the genital organs. However, any area of the skin may be affected, including the
pharynx, rectum, or lips. The
chancre teems with spirochetes. It
persists for 2-6 weeks, and then it disappears spontaneously.
·
Secondary
syphilis can develop 17
days to 6.5 months after infection.
Symptoms can last from 2 to 6 weeks. The symptoms of 2nd syphilis include fever, and a
constitutional flulike illness, as well a swollen lymph nodes reminiscent of
infectious mononucleosis. A rough,
reddish-brown rash that appears on the palm of your hands or the soles of your
feet, which normally does not itch.
Condylomata lata or syphilitic “warts”, moist, raised or
elevated skin lesions, may be found in the anus or genital area, mucous patches,
round, grayish white sores, can appear on the mouth, throat and cervix. The skin rash that appears may be
mistaken for measles, rubella, or chickenpox. Loss of the eyebrows often occurs, and patchy loss of hair
results in “moth-eaten” areas commonly seen on the head. Involvement of the liver may lead to
jaundice and suspicion of hepatitis.
In untreated patients, the symptoms last several weeks, and death may
result. Most patients recover, but
they bear pitted scars from the lesions and remain “pockmarked.” These individuals now enter a latent
stage, during which they continue to be infectious.
·
Latent
syphilis is defined as
the time where there are no signs or symptoms of the disease. It develops from 2 to more than 30
years after infection. The only
way to test for infection during the latent period is by blood test. A relapse of secondary syphilis can
occur once the disease has entered the latent stage. This normally will happen during the first 2 years of
latency.
·
About one
third of untreated patients eventually develop tertiary syphilis. Symptoms of the late stage or tertiary
syphilis can occur 2 to 30+ years after infection. This stage occurs in many forms, but most commonly it
involves the skin, cardiovascular system, and nervous system. The hallmark of tertiary syphilis is
the gumma, a soft,
gummy granular lesion. In the
cardiovascular system, gummas weaken the major blood vessels, causing them to
bulge and burst. In the spinal
cord and meninges, gummas lead to degeneration of the tissues and
paralysis. In the brain, they
alter the patients personality and judgement and cause insanity so intense that
for many generations, people with tertiary syphilis were confined to mental
institutions. It is conceivable
that our ancestors failed to equate the chancre of primary syphilis with the
horrible symptoms of tertiary syphilis because the stages were so distantly
separated in time. If treated
during this period, gummas will usually disappear. Though treatment at this phase will cure the disease and
stop future damage to the body, it cannot repair or reverse the damage that
occurred before treatment.
·
In
pregnant women, the
spirochetes penetrate the placental barrier after the fourth month of
pregnancy, causing congenital syphilis in the fetus. Syphilitic skin lesions and open sores may be apparent in the
newborn, or symptoms may develop weeks after birth. Affected children often suffer poor bone formation,
meningitis, or Hutchinson’s triad, a combination of deafness, impaired
vision, and notched, peg shaped teeth. Late congenital
syphilis has similar symptoms to tertiary syphilis in adult, though heart
complications rarely occur in cases of congenital syphilis.
· Diagnosis of Syphilis can be done by looking for antibodies for the bacteria or by testing fluid taken from lesions or swollen lymph nodes to look for antigens.
·
Penicillin is the drug of choice for the primary,
secondary and latent stages of the disease, but antibiotics are ineffective in
tertiary syphilis.
·
T.
pallidum multiplies very
slowly in the tissues, partly because of its 33 hour generation time. This factor encourages successful
therapy.
· Shyphilis is currently among the most reported microbial disease in the US. Statistics indicate that about 45,000 people are afflicted with the disease annually, of whom about 9000 are in the primary or secondary stage. Some public health microbiologist believe that for every case reported, as many as nine cases go unreported. Up until 2000, the reported rate of syphilis in the US was at its lowest level since reporting began in 1941. In 2001, the number of cases reported increased slightly by a little over 2%.
http://www.ashastd.org/stdfaqs/gonorrhea.html
Historical background
Gonorrhea
has been and is a major problem causing such severe consequences as sterility,
blindness, and in certain situations, death. While this disease has been recognized as human affliction
since ancient times, it remained for the well-known physician Galen, practicing
in Rome during the golden age of Greek medicine, to give the disease its
name. He mistakenly believed that
the discharge referred to a Rheos, was composed of semen, or Gonos. Thus, the name gonorrhea, meaning
the flow of seed, was coined.
One of the better-known common names for this disease, “clap,” was derived from the term clappoir used for
Parisian houses of prostitution in the Middle Ages.
Syphilis
and gonorrhea were considered to be one and the same disease for almost 300
years. The characteristic
discharge of gonorrhea was considered to be the first symptom of syphilis. It was not until the tragic
self-inflicted exposure by the English surgeon John Hunter in 1767 that it
was found that there were two diseases and not one. Hunter obtained pus from a patient with
gonorrhea and injected himself.
Unfortunately, the specimen was contaminated with the T. pallidum, and
Hunter fell victim to the effects of both diseases. He subsequently developed a classic case of syphilitic heart
disease and died in 1793. It is
interesting to note that even though syphilis and gonorrhea were shown to be 2
separate diseases in the 1790s, many physicians still considered them to be the
same for another 50 years.
Gonorrhea
is the second most frequently reported microbial disease in the US, after
chlamydia. Gonorrhea remains an
epidemic.
The disease
·
In males, gonorrhea occurs primarily in the urethra. Onset usually is accompanied by a
tingling sensation in the penis, followed in a few days by pain when
urinating. There is also a thin,
watery discharge at first, and later a more obvious whitened, thick fluid that
resembles semen. Frequent
urination and an urge to urinate develop as the disease spreads further into
the urethra. The lymph nodes of
the groin may also swell, and sharp pain may be felt in the testicles. Unchecked infection of the epididymis
may lead to sterility. Symptoms
tend to be more acute in males then in females.
·
Most men exhibit
symptoms within 2 to 5 days after exposure, with a possible range of one to 30
days.
Gonorrhea does not
restrict itself to the urogenital organs.
·
Gonococcal
pharyngitis may develop in the
pharynx if bacteria are transmitted by oral-genital contact; patients complain
of sore throat or difficulty in swallowing.
·
Infection of the rectum,
or gonococcal proctitis, is also
observed, especially when practicing anal intercourse.
·
Transmission to the eyes
may occur by fingertips or towels, and keratitis may develop.
·
Gonorrhea is
particularly dangerous to infants born to infected women. The infant may contract gonococci
during passage through the birth canal and develop gonococcal opthalmia. The
most common symptoms in newborns include conjunctivitis and pneumonia, which
usually develop 5-12 days after birth.
Diagnosis
Detection of gonorrhea can
be done by bacterial DNA amplification, Gram stain test (mostly for men),
culture test (very relieable test).
People infected with
gonorrhea are often co-infected with chlanmydia; therefore, treatment for
gonorrhea and chlamydia is prescribed.
The treatment for
gonorrhea includes the following:
Cepahlosporin drugs or
Quinolone class drugs. For
Chlamydia, doxycycline, azithromycin.
An attack of gonorrhea
does not immunize one to future attacks, apparently because the immune system
does not response strongly enough to the first attack. There is no vaccine available.
Chlamydia
http://www.ashastd.org/stdfaqs/chlamydia.html
In
the US, chlamydia is the most common bacterial STD. In 2000, 702,093 cases of
chlamydia were reported to the CDC.
However, it is estimated that 3 million cases actually occurred and as
many as 1 in 10 adolescent females test positive for chlamydia.
Until
the 1950s the Chlamydia were considered to be viruses, or virus-like because of
their extremely small size, and atheir need for living cells in order to
multiply. With improvements in
technology and a better understanding of their properties, the chlamydia are
now considered to be bacteria and not viruses. The reasons for this decision include their cellular nature,
and a susceptibility to antibiotics.
The
chlamydia are distinguished from all other types of bacteria on the basis of an
unusual life cycle in which they appear in two different forms, initial bodies
(Ibs) which are mainly concerned with increasing the clhlamydial population in
an infected cell, and elementary bodies (Ebs) which represent the infectious
stage of the cycle. An infection
is started by an EB attaching to the surface of a susceptible host cell. Once inside, the pathogen is not
protected from the defenses of the host and is free to form Ibs which reproduce
rapidly and eventually fill the cell. Within 20 hrs after infection the Ibs reorganize and
develop into infectious Ebs, which are released to attack and infect nearby
susceptible cells. Each infected
cell may contain up to 10,000 Chlamydia.
A complete turn of the cycle from beginning to end takes 35-48 hrs. Only Ebs are adapted to survive outside
of host cells.
Two
major means of transmission are recognized for C. trachomatis. These are sexual and congenital.
Newborns get infections by passing through an infected birth canal.
It
is estimated that up to 77% of chlamydia infections in women are
asymptomatic. These undetected and
untreated cases are associated with PID.
Symptomatic women have a thick discharge consisting of mucus and
pus. Soreness in pelvic area,
lower back pain, lower abdominal pain, burning sensation on urinating slight
fever, frequent need to urinate may be other symptoms. Salpingitis, infertility, urethritis,
uterine bleeding, endometritis, pregnancy complication and inflammation
involving the liver are complications that may result from Chlamydia infection.
C.
trachomatis is known to cause several different infections in men. These include inflammation of the
urethra of nongonococcal urethritis (NGU), a complication of chlamydial
infections, an inflammation of the epididymis, or epididymitis, and an
inflammation of the rectum and anus known as proctitis. A number of STD agents and other
pathogens can also cause infection of the rectum and anus. NGU is most frequently caused by C.
trachomatis. The bacterium
ureaplsma urealyticum is another cause of NGU. Since more than half of the men with NGU are without
symptoms, or experience only a mild discomfort, medical care often is not
sought. The most common symptom is
the presence of a thick pus-like discharge that develops about 3 weeks after
contact with an infected person.
Left untreated, NGU may lead to epididymitis and sterility. Arthritis is
a common aftereffect of sexually acquired NGU. It typically develops 1-4 weeks after the initial infection.
In
Newborns infected while passing through the birth canal, ophthalmia neonatorum,
pneumonia, and middle ear infections may result. Studies indicated that 18-44% of infants born to infected
mothers are likely to develop an eye infection and 11-20% are likely to develop
pneumonia.
The disease
·
Chlamydia is a
gonorrhealike disease transmitted by sexual contact. The causative agent is Chlamydia trachomatis, a species of chlamydiae. Chlamydia trachomatis is very small 0.25µm in diameter. It grows only in living tissue and it has a complex
reproductive cycle. The organism
appears to be a specific parasite of humans.
·
The disease has an
incubation period of about 1-3 weeks, and the symptoms are remarkably similar
to those of gonorrhea, although somewhat milder.
·
Approximately, 75% of
women and 50% of men do not experience symptoms. If a person does have symptoms, they usually develop within
one to 3 weeks after exposure to chlamydia.
·
The symptoms of
chlamydia are similar to the symptoms of gonorrhea and the 2 infections are
often confused.
·
Both men and women can
experience proctitis (inflamed
recturm), urethritis (inflamed
urethra) and conjunctivitis
(inflamed eyelid). Most infections
of the mouth and throat are asymptomatic.
If present, symptoms are soreness and redness in the throat or
mouth. The most common
complications in newborns include conjuctivitis and pneumonia.
·
Most women are
asymptomatic, but if symptoms are
present they may be minor.
Symptoms may include: vaginal discharge, burning sensation during
urination. If the infection spreads to the fallopian tubes, women may
experience lower abdominal and lower back pain, pain during intercourse,
bleeding between menstrual periods, nausea or fever. Females often note a
slight vaginal discharge, as well as inflammation of the cervix. Burning pain is also experienced on
urination, reflecting disease in the urethra. In complicated cases, the disease may spread to the
Fallopian tubes, causing adhesions that block the passageways
(salpingitis). Some think that PID
is a more likely consequence of chlamydia than of gonorrhea. Often, there are few symptoms of
disease before the salpingitis manifests itself, thus adding to the danger.
·
Men may be asymptomatic or symptoms may be minor. When symptomatic, men may experience
one or more of the following: pus or watery or milky discharge from the penis,
pain or burning during urination, pain or swelling of the testicles. In males,
chlamydia is characterized by painful urination and a discharge that is more
watery and less copious than in gonorrhea. The discharge is often observed after urinating for the
first time in the morning.
Tingling sensations in the penis are generally evident. Inflammation of the epididymis may
result in sterility, but this complication is uncommon.
Diagnosis
Diagnosis consist of
nucleic acid amplification test, chlamydia culture, antibody test to test for
chlamydia antibodies, direct florescent antibody test-test that detect
chlamydia antigens.
Treatment
Tetracycline is an
effective treatment. In pregnant
women, erythromycin is the treatment.
Complications
·
Untreated chlamydia
infections in women may lead to PID. Untreated chlamydia in men may lead to
prostitis (inflammation of the prostate gland) urethral scarring, infertitlity,
epididymitis.
·
Chlamydial
pharyngitis and proctitis are also possible.
·
Reither’s Syndrome
(RS) is a disorder that causes 3 seemingly unrelated symptom-arthritis, redness
of the eyes, and urinary tract problems.
Chlamydia trachomatis is
one of the bacteria that can cause RS.
Most men and women with chlamydia do not develop RS. RS usually affects men between the ages
of 20 and 40. Women can develop
the disorder, though less often than men and with symptoms that are milder and
less noticeable.
·
Newborn may contract C.
trachomatis from an infected mother
and develop a disease of the eyes known as chlamydial opththalmia. Chlamydial
pneumonia may also develop in
newborns from an exposure to C. trachomatis during birth.
Thus, untreated chlamydia in infants can lead to blindness, complication
of pneumonia, which can include death.
Lymphogranuloma Venereum
Throughout
most of its history Lymphogranuloma Venereum (LGV) has been confused with other
STDs, particularly syphilis, genital herpes, and chancroid. LGV is caused by specific strains
of Chlamydia trachomatis. As with other chlamydial infections,
LGV is almost exclusively spread through sexual contact.
The
disease appears to be more common in tropical parts of the world such as
Southeast Asia, Africa, South America, and the West Indies. In the US, LGV predominately is found
among African-American persons with a low economic status.
The
most frequent sign of LGV infection and the main reason an infected person
seeks medical attention is the increasing number of swollen lymph nodes in the
groin. These develop 2-6 weeks
after infection, and because of anatomical differences are found more commonly
in men than in women.
·
In the primary stage,
there is the appearance of a small red spot or shallow sore. Such primary lesions also may be found
on the fingers, tongue, or around the rectum and anus. The location of lesions reflects the
type of exposure and the first site of infection.
·
The secondary stage is
marked by noticeable, enlarged, hard, and painless lymph nodes on one side of
the groin. This condition
generally develops within 1-3 weeks after the first signs of the infection
disappear. As this stage continues
the lymph nodes on both side of the groin may become involved and give rise to
a diagnostic physical feature known as the “groove sign.” In some cases these enlarged lymph
nodes may get smaller in size, break, and develop into pus-draining sores. Fever, chills, headaches, and muscular
aches are typical symptoms found with this stage of LGV infection.
·
The tertiary stage
includes a variety of serious and destructive effects resulting from the
spreading of the infection. Many
of these effects may be disabling as well as disfiguring, and include a
narrowing of the rectum, the formation of abnormal passages or tunnels between
the rectum and vulva, deep sores, and severe swelling of the genitalia
resulting in the condition known as elephantiasis.
Diagnosis
Enzyme tests, microscopic
staining techniques, culture procedures, and detection of antibodies to the
organism are used in diagnosing the causative agent.
Treatment
Antibiotics such as
tetracyclines are used as treatments.
Advanced forms of LGV may require surgery to lessen the effects of the
infection or to correct any deformities.
Ureaplasmal Urethritis
Ureaplasmal
urethritis is another type of nongonococcal urethritis. It is caused by Ureaplasma
urealyticum, a mycoplasma,
so-named because of its ability to digest urea in culture media. At about 0.15µm in size, U.
urealyticum is one of the smallest known bacteria that cause human disease.
The
symptoms of ureaplasmal urethritis are similar to those of gonorrhea and
chlamydia. A distinction can
be made between the diseases because in ureaplasmal urethritis, the discharge
is variable in quantity and the urethral pain is usually aggravated during
urination. Symptoms are often very
mild. Transmission is generally by
sexual contact.
Infertility
is one consequence of ureaplasmal urethritis because low sperm counts and poor
movement of sperm cells have been observed in males. Salpingitis in females has also been described. Moreover, Ureaplasma is capable of
colonizing the placenta during pregnancy, and reports have linked it to
spontaneous abortions and premature births. Twenty five per cent of NGU cases may be ureaplasmal
urethritis.
Treatment
Penicillin
cannot be used to treat ureaplasmal urethritis because U. urealyticum has no cell wall. Tetracycline is currently the
drug of choice.
Diagnosis
Diagnosis
often depends on eliminating gonorrhea or other types of NGU as possibilities,
and for this reason, cases are not often recognized.
Chancroid
http://www.ashastd.org/stdfaqs/chancroid.html
chancroid
is believed to be more prevalent worldwide than gonorrhea or syphilis.
Chancroid
or soft chancre has been recognized as a disease for centuries. It was, and often still is, confused
with other STDs including syphilis.
Chancroid
is a sexually transmitted infection caused by Haemophilus ducreyi. Men
have a much higher incidence of this disease than women. Moreover, chancroid is more commonly
found in uncircumcised men.
Chancroid
is found worldwide, but appears to be most common in tropical and subtropical
countries. This STD is believed
to be an infection of individuals with relatively low standards of cleanliness.
The
incubation period for chancroid in males varies from 1-14 days following sexual
contact. In females, this period
is somewhat longer for reasons that are not clear.
Typical
lesions or chancroidal sores first appear at the sites of sexual contact. These lesions which begin as small red
pimples, develop into sores or ulcers within 24 h. Classic chancroidal ulcers, which occur in the majority of
men, generally are painful, irregular in shape, soft, and sharply
outlined. A foul odor occurs with
some infections.
The
most common locations for such lesions in males include the internal surface of
the foreskin, glans, penis, and shaft of the penis. The scrotum, anus, and thighs also may be involved. In women, lesions develop on the labia,
clitoris, vestibule, and anus.
While extragenital ulcers are rare, they can occur on fingers, breasts,
lips, the tongue, etc.
Within
one week after the ulcer forms, the lymph nodes in the groin generally become
swollen in 40% of men and 25% of women.
If left untreated, these lesions develop into deep, pus producing sores.
Diagnosis
Diagnosis is made by
isolating the bacteria Hemophilus Ducreyi in a culture from a genital ulcer. The chancre is often confused with syphilis, herpes or lymphogranuloma venereum
Treatment
Antibiotics are the
treatment (check weblink)
Granuloma Inguinale
Granuloma
inguinale results from infection with Calymmatobacterium granulamatis. Sexual
contact is considered to be the means of disease transmission.
The
incubation period ranges from a few days to 4 or 5 months. In most cases of infection, the main
lesion, a firm red pimple or papule,
develops on the genitalia. Additional
papules soon occur, eventually break open, and become sores of varying sizes
and appearances. While many
such ulcers are painless, others are tender, bleed on touch, and cause
disfiguring and even destruction of genitalia. In men, for example, if left untreated, the infection may
destroy the entire penis.
Long-lasting infections in women may result in severe swelling of and
the formation of growths of the external genitalia.
Diagnosis
The finding of the characteristic
genital lesions, and demonstrating the causative agent in specimens taken from
the infected person are the diagnostic measures. In the laboratory the infection is confirmed by showing the
presence of Donovan bodies. These
are large, nucleated cells containing the causative bacteria.
Treatment
Antibiotics such as
ampicillin or the tetracyclines are used.
Bacterial Vaginosis
http://www.ashastd.org/stdfaqs/bv.html
http://www.ashastd.org/stdfaqs/vaginitis.html
Vaginal infection can be
caused when the normal flora is out of balance. Such conditions, which include pregnancy, menstruation, and
the use of oral contraceptives, change the acid level and sugar concentration
in the vagina. Several
microorganisms are able to take advantage of the situation and establish an
infection. One of these, the
bacterium Gardnerella vaginalis interacts with other bacterium to cause
bacterial vaginosis (BV). Thus,
unlike other STDs, BV is not cause by a single infectious agent.
G. vaginalis currently is
involved with about 50% of vaginosis cases. Men occasionally get an infection of the penis after sexual
contact with a woman who has vaginosis.
The disease agent can be spread to newborn passing thought an infected
birth canal.
The major complaint
expressed by infected women is the presence of a foul-smelling, or fishy,
vaginal odor. This odor may
increase after sexual intercourse or menstruation. Infected men
also may have discharge.
Diagnosis
The diagnosis of bacterial
vaginoiss caused by G. vaginalis is made on the physical finding of a foul
smelling, or fishy discharge and the microscopic examination of a vaginal
discharge in the laboratory. When
potassium hydroxzide is added to vaginal secretions, a distinct and intense
fishy odor is produced. This
is a conclusive test for diagnosis.
Microscopic examination of specimens showing the surfaces of vaginal
cells overrun by G. vaginalis also is used to confirm the diagnosis.
Treatment
Prescription medication,
usually antibiotics, depending on the organism causing the infection is used to
treat and/or cure BV.