Sexually
Transmitted Disease (STD) Introduction: A
few decades ago sexually transmitted diseases were relatively simple: there was
gonorrhea, which was thought to be most common; then syphilis, which was less
common and "nongonococcal urethritis", which could only be determined
to be present on clinical grounds, but where many authorities who questioned whether
it even existed. AIDS did not exist and herpes was a rare condition. Today
we know that most venereal diseases are due to chlamydia, which is caused by Chlamydia
trachomatis. Others are due to Mycoplasma genitalium or Ureaplasma urealyticum.
There still is gonorrhea that used to be "number one" in the past and
also the now even less common classical venereal disease, syphilis. However, the
feared new "kids on the block" are AIDS and hepatitis C. Strictly speaking
hepatitis C belongs to the hepatitis
infections, a gastroenterological problem. However, I am mentioning it here as
it is intimately connected to peoples' sexual practices. I will deal with
each sexually transmitted disease separately. The table above shows an overview
and the blue underlined names are direct links to the various chapters where more
details can be found. Hepatitis C This viral hepatitis
and occasionally also hepatitis B are transmitted in more than 45% by sharing
of needles when both partners are addicted to injectable drugs. Otherwise
this form of hepatitis is a gastrointestinal disease that affects the liver and
that is transmitted through close saliva contact or contact with infected semen
that is swallowed. Other means of transmitting the hepatitis virus are contaminated
drinking water, tattoo ink or feco-oral contamination. In only 4 to 10% of cases
hepatitis C is trasmitted sexually. The mechanism of transmission in these cases
seems to involve microabrasions of the mucous membranes in contact with subsequent
mini-exchange of blood through these portals into the blood stream. This mode
of transmission through microabrasions of mucous membranes is more likely to occur
with anal sex (Ref. 4). See link for more details: hepatitis
C Herpes or "genital herpes"
This is a viral skin infection that has been dealt with under that category.
Type 2 herpes simplex virus (HSV-2) is the main cause of genital herpes, but 20
to 30% can also be caused by type 1 (HSV-1), which more commonly affects the lips
and skin around the mouth. For more details about these viruses see this link:
herpes simplex. Mycoplasma
genitalium and Ureaplasma uealyticum These sexually transmitted
bacteria are very difficult to culture and are not assayed routinely in the lab.
As they are covered by the same antibiotics that are effective against
Chlamydia, in most cases it is not important to distinguish between these strains.
However, there is data to suggest that some of the resistant cases of Chlamydia
are sometimes not due to Chlamydia resistance, but rather due to multi-bacterial
infection. After Chlamydia has been eradicated these other pathogens stay behind
that are more difficult to treat. Mostly they just need longer antibiotic treatment
in order to be eradicated. These cases should be referred to a center for sexually
transmitted diseases as special tests might be required that can only be done
in specialty labs.
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