Clinical immunology is the study of diseases caused by disorders of the immune system (failure, aberrant action, and malignant growth of the cellular elements of the system). It also involves diseases of other systems, where immune reactions play a part in the pathology and clinical features.
2. ā¢ Under this category of sexually transmitted diseases you will look at
the following diseases:
ā¢ Syphilis
ā¢ Chancroid
ā¢ Lymphogranuloma venereum
Introduction
3. ā¢ Syphilis is a sexually transmitted disease caused by the spirochete bacterium
Treponema pallidum, subspecies pallidum. Direct human to human contact is
required for transmission to occur.
ā¢ The route of transmission of syphilis is almost always through sexual contact,
although there are other ways through which transmission can occur, for
example, from mother to child as in the case of congenital syphilis, through blood
transfusion, kissing and percutaneous injury (Todd et al., 2002).
1-Syphilis
4. ā¢ The symptoms of syphilis depend on the stage of the disease. They
are divided into primary, secondary and tertiary symptoms.
Symptoms of Syphilis
5. ā¢ Primary syphilis is typically acquired through direct sexual contact
with the infectious lesions of a person with syphilis.
ā¢ A skin lesion appears at the point of contact approximately 10 to 90
days after the initial exposure (average 21 days). This lesion, called a
chancre, is a firm, painless skin ulceration localised at the point of
initial exposure to the spirochete, often on the penis, vagina or
rectum.
Primary Syphilis
6. ā¢ Rarely, there may be multiple lesions present although typically only
one lesion is seen. The lesion may persist for four to six weeks and
usually heals spontaneously. Local lymph node swelling can occur.
Many patients do not seek medical care immediately (Todd et al.,
2002).
Contiā¦.
7. ā¢ Secondary syphilis occurs approximately one to six months (commonly six
to eight weeks) after the untreated primary infection.
ā¢ There are many different manifestations of secondary disease. There may
be a symmetrical reddish-pink non-itchy rash on the trunk and extremities.
The rash can involve the palms of the hands and the soles of the feet. In
moist areas of the body, the rash becomes flat, broad, whitish lesions
known as condylomata.
Secondary Syphilis
8. ā¢ Other symptoms common at this stage include fever, sore throat,
malaise, weight loss, headache, meningismus, and enlarged lymph
nodes.
Contiā¦.
9. ā¢ Tertiary syphilis usually occurs one to 10 years after the initial
infection, though in some cases it can take up to 50 years.
ā¢ This stage is characterised by the formation of gummas which are
soft, tumour-like balls of inflammation known as granulomas. They
may appear almost anywhere in the body including in the skeleton.
Tertiary Syphilis
10. ā¢ Other characteristics of untreated tertiary syphilis include
neuropathic joint disease, which is a degeneration of joint surfaces
resulting from loss of sensation and fine position sense
(proprioception).The more severe manifestations include
neurosyphilis and cardiovascular syphilis.
Contiā¦.
11. ā¢ Diagnosis of syphilis is based on the following tests:
ā¢ Dark-field microscopy
ā¢ Serologic tests
Laboratory diagnosis of Syphilis
12. ā¢ This is also called screening tests. They are easy to perform and they use a
cardiolipin-based antigen to detect antibodies against Treponema pallidum
antigens.
ā¢ Examples of non-treponemal tests include the following:
ā¢ VDRL (venereal disease research laboratory)
ā¢ RPR (rapid plasma reagin)
Non-Treponemal Tests
13. ā¢ These tests are also known as confirmatory tests. They use Nicholās
antigen to detect specific antibodies against Treponema pallidum.
Examples of Treponemal tests include the following:
ā¢FTA-Abs (fluorescent treponemal antibody-absorption)
ā¢ TPHA (treponema pallidum hemagglutination assay)
Treponemal Tests
14. The treatment of syphilis will depend on the following stages:
ā¢ Early syphilis
ā¢ Late syphilis
ā¢ Neurosyphilis
The treatment of syphillis for the various stages is described as follows:
Treatment of Syphilis
15. ā¢ Early syphilis treatment regimen includes the following:
ā¢ Procaine benzylpenicillin G. 600000 U im daily for 10 days
ā¢ Benzathine penicillin G 2.4 million U I.m once a week for two doses
Early Syphilis Treatment
16. ā¢ For patients who are allergic to penicillin the following alternative
treatment is used:
ā¢ Doxycycline 100mg orally 12 hourly for 14 days
ā¢ Erythromycin 500mg orally six hourly for 14 days. (Todd, 2002)
Contiā¦.
17. ā¢ During this stage the treatment regimen includes the following:
ā¢ Procaine benzyl penicilline G. 600000 U im daily for 17 days
ā¢ Benzathine penicillin G 2.4 million U I.m once a week for three doses
ā¢ For patients allergic to penicillin the alternative regimen is
Doxycycline 100mg orally 12 hourly for 28 days. (Todd, 2002)
Late Syphilis Treatment
18. ā¢ Neurosyphillis treatment regimen includes the following:
ā¢ Procaine benzylpenicilline G. 1.8-2.4 million U im daily plus
probenecid 500mg orally six hourly for 17 days
ā¢ Benzylpenicillin 3-4 G 2.4 million U i.v 4-hourly for 17 days.
ā¢ Penicillin allergy: Doxycycline 100mg orally 12 hourly for 28 days
(Todd, 2002)
Neurosyphillis Treatment
19. ā¢ During pregnancy, the procaine regimen depends on the stage of syphilis. For mothers who are
allergic to penicillin give erythromycin 500mg orally six hourly for 14 days. Investigate and treat
the baby after birth.
ā¢ Abstinence from any sexual activity
ā¢ Early diagnosis and treatment
ā¢ Education and counselling on safer sexual behaviour in persons at risk
ā¢ Identification of asymptomatic infected persons and of symptomatic persons unlikely to seek
diagnostic and treatment services.
Treatment of Syphilis during Pregnancy
20. ā¢ Chancroid (also known as āsoft chancreā) is a sexually transmitted infection
characterised by painful sores on the genitalia. It is a bacterial infection
caused by the fastidious gram-negative streptobacillus Haemophilus
ducreyi. Chancroid is spread from one person to another through sexual
contact. Uncircumcised men are three times at risk of contracting
chancroid than circumcised men (Mcadams and Sharps, 2005).
2-Chancroid
21. ā¢ After an incubation period of one day to two weeks, chancroid begins with a small bump
that becomes an ulcer within a day of its appearance.
ā¢ The ulcer characteristically:
ā¢ Is painful.
ā¢ Multiple.
ā¢ Soft.
Symptoms and Signs of Chancroid
22. ā¢ Has sharply defined, undermined borders.
ā¢ Has irregular or ragged borders.
ā¢ Lymphnodes are painful enlarged and often suppurative (Nordberg,
2000).
Contiā¦.
23. ā¢ The following are similarities between a chancre and chancroid:
ā¢ Both originate as pustules at the site of inoculation, and progress to ulcerated
lesions.
ā¢ Both lesions are typically 1-2cm in diameter.
ā¢ Both lesions are caused by sexually transmissible organisms.
ā¢ Both lesions typically appear on the genitals of infected individuals.
ā¢ Both lesions can present at multiple sites and with multiple lesions.
Similarities between a Chancre and Chancroid
24. ā¢ The following are differences between a chancre and chancroid:
ā¢ Chancre is a lesion typical of infection with the bacterium that causes syphilis,
treponema pallidum
ā¢ Chancroid is a lesion typical of infection with the bacterium haemophilus ducreyi.
ā¢ Chancres are typically painless, whereas chancroid are typically painful.
ā¢ Chancres are typically non-exudative, whereas chancroid typically have a grey or
yellow purulent exudates.
Differences between a Chancre and Chancroid
25. ā¢ Chancres have a hard (indurated) edge, whereas chancroid have a soft edge.
ā¢ Chancres heal spontaneously within three to six weeks, even in the absence of
treatment.
ā¢ Chancres can occur in the pharynx as well as on the genitals (Nordberg, 2000).
Contiā¦.
26. ā¢ The recommended treatment for chancroid is a single oral dose (two tablets) of
azithromycin or a single IM dose of ceftriaxone or oral erythromycin 500mg qid
for seven days (Nordberg, 2000).
Treatment of Chancroid
27. ā¢ The following measures are important in the prevention of chancroid:
ā¢ Abstinence from any sexual activity
ā¢ Early diagnosis and treatment
ā¢ Education and counselling on safer sexual behaviour in persons at risk
ā¢ Identification of asymptomatic infected persons and of symptomatic persons
unlikely to seek diagnostic and treatment services.
Prevention and Control of Chancroid
28. ā¢ Lymphogranuloma venereum is a sexually transmitted disease caused by three
different types (serovars L1, L2, or L3) of chlamydia trachomatis.
ā¢ Chlamydia are small obligate intra-cellular parasites and were once considered to
be viruses. The organism travels from the site of inoculation down the lymphatic
channels to multiply within mononuclear phagocytes found in the lymph nodes
(Murray et al., 1990).
3-Lymphogranuloma Venereum (LGV)
29. ā¢ A small papule or vesicle may develop after several days or weeks in
any part of the external genitalia, anus, or rectum. It may remain
unnoticed and heal after a few days. Then regional lymphnodes swell
and become mattered and painful.
Signs and Symptoms of Lymphogranuloma Venereum
30. ā¢ In males the inguinal nodes are most commonly affected and they
discharge pus through multiple sinus. In females and in homosexual
males, the perirectal nodes are prominently involved (Brooks et
al,.2004).
Contiā¦.
31. ā¢ The diagnosis of lymphogranuloma venerenum can be made using the
following laboratory tests:
ā¢ Isolation of C. trachomatis, serotype L1, L2, or L3 from clinical specimen.
ā¢ Direct immunofluorescence which shows inclusion bodies in leukocytes of
an inguinal lymph node (bubo) aspirate, or positive
microimmunofluorescent serologic test for a lymphogranuloma venereum
strain of C. Trachomatis.
Laboratory Criteria for Diagnosis of Lymphogranuloma Venereum
32. ā¢ Treatment involves antibiotics and may involve drainage of the
buboes or abscesses by needle aspiration or incision.
ā¢ Further supportive measures may need to be taken such as dilatation
of the rectal stricture, repair of recto-vaginal fistulae, or colostomy for
rectal obstruction.
Treatment of Lymphogranuloma Venereum
33. ā¢ Common antibiotic treatments are tetracycline and doxycycline. All
tetracyclines, including doxycycline are contraindicated during
pregnancy and in children due to effects on bone development and
tooth discoloration (Scott, 2006).
Contiā¦.
34. ā¢ Children and pregnancy mothers should be given erythromycin.
Contiā¦.
35. ā¢ Abstinence or having sex with only one person.
ā¢ Use a latex condom and lubricant every time you have sex.
ā¢ Get tested for asymptomatic STDs including HIV.
Prevention and Control of Lymphogranuloma Venereum