This document discusses several important sexually transmitted infections (STDs). It begins with an introduction to STDs, noting that over 20 have been identified. Important facts provided include that STDs often have no symptoms but people can still transmit them, and some STDs can cause infertility, ectopic pregnancy, or increase HIV risk. Common and important STDs are then discussed in more detail, including chlamydia, gonorrhea, genital herpes, HPV, and syphilis. Diagnostic methods and clinical presentations are summarized for each infection.

1. Introduction.
Important facts
Important STDs
Discussion about common & important STDs.

2. STDs, once called venereal diseases, also known as
Sexually transmitted infections or STI.
Defined as the infections that can be
transferred from one person to another
through sexual contact
More than 20 STDs have now been identified.
Introduction

3. 1. They affect men & women of all backgrounds &
economic levels, being most prevalent among
teenagers & young adults, nearly two-thirds
occur in people <25 yrs.
2. The incidence is rising- young people become
sexually active earlier, have multiple sex partners.
3. STDs may be asymptomatic, even then infected
person is capable of transmitting the disease to partner.
Important Facts about STDs

4. 4. Some STD can spread
into the uterus, tubes
& ovaries to cause
PID,which in turn is a
major cause of
infertility & ectopic
pregnancy.
5. In female some STD
may be associated
with cervical cancer.
e.g.HPV
6. STD can be transmitted vertically
from mother to baby before, during
or immediately after birth.
7. When diagnosed & treated early, many
STD can be treated effectively.
8. Having STD increases the risk for
infection with HIV.
5
Facts (contd….)

5. 1. Chlamydial infection
2. Gonorrhea
3. Genital Herpes.
4. HPV & genital warts.
5. Syphilis
6. HIV/AIDS.
7. Trichomoniasis
8. Hepatitis B
9. Chancroid
10. Bacterial vaginosis
11. Granuloma inguinale (donovanosis).
12. Lymphogranuloma venereum
13. Molluscum contagiosum
14. Pubic lice
15. Scabies
16. Vaginal candidiasis.
Important STDs

6. 5

7. Chlamydia are very small bacteria , obligate
intracellular bacteria that grow within cytoplasmic
vacuoles, stain poorly with Gram-stain but have the
typical LPS of Gram – ve bact.

8. Three species for Chlamydia
- C. trachomatis.
Resp. T
new genus
- C. psittaci
chlamydophila
- C. pneumoniae

9. Enter through minute abrasions in the mucosal surface.
Specific receptors endocytosis C. t vesicle inhibite
Lysozyme fusion ( unknown mechanism ) After formation of
metabolically RBs (binary fission ) 10 hs fresh progeny (within
20hs ) release of new EBs to the extracellular environment.
Pathogenesis

10. The lifecycle of Chlamydia. (EB, elementary body; RB, reticulate body.)

11. Clinical syndromes and complications caused by C.
trachomatis, serotypes D-K.

12. Chlamydial inclusion bodies stained dark brown
with iodine

13. Direct fluorescent antibody test for Chlamydia trachomatis.
Elementary bodies can be seen as bright yellow-green dots
under the ultraviolet microscope

14. - The genus Neisseria contains two
important human pathogens.
N . meningitides
(meningococus )
N .gonorrhoeae
(gonococcus )

15. They are Gram – ve diplococci
Obligate human pathogen .
Found inside polymorph or pus
of the inflammatory exudates.
- It is exclusively a human
pathogen

16. Gonos
(seed )
Rhoie
( flow )
- It is classical venereal dis .
- Spread almost by sexual contact.
- Having a short incubation period.
- Easy to diagnose and treat.
- It is the 2nd infection in UK , with highest rates
are seen in ♂ ( 20 – 24 ys) and ♀ ( 16 – 19 ys ).

17. • Cervix
• Urethra
• Rectum
• Pharynx
• Conjunctiva
Infection is generally limited to ;
superficial mucosal surface ẃ is lines é
columnar epith.

18. Squamous epith . ẃ lines the
adult vagina is not susceptible .
The prepubertal vaginal epith. ẃ
has not been keratinized under the
influenz of estrogen may be
infected. → as vulvovaginitis
NB.

19. The spread of Neisseria gonorrhoeae is
facilitated by various virulence factors. Changes
in the surface structure of the gonococcus
render the organism avirulent

20. Local and systemic spread of gonococcal infection
and complications

21. - Gram staining of a smear ( 95% sensitive ).
- It is a fastidious microbe ,
- Requiring humidity ( 5-7% co2 )and
- Complex media for growth……….
combination of oxidase + ve colonies
and Gram- ve diplococci provides a
presumptive diagnosis .
Fluorescent – antibody staining
NB.

22. -Co – agglutination
-Specific biochemical tests ,glucose.oxidase
-DNA probes may be used for confirmation
- PCR based methods are available in some
specified lab
-Blood culture for DGI

23. - Rapid diagnosis.
- Use of effective antibiotics.
- Tracing , examination and treatment of
contacts.
– No vaccine till now ;
-antigenic variation of the pilli.
- outer memb. Ptns are antigenically
variable.
- lack of suitable animal models.
NB.

24. Gonococcal skin lesion: an intensely
inflamed.

25. Gonococcal arthritis affecting the ankle 1 week
after contact with a new sexual partner

26. Gram stain of N.gonorrhoea

27. - Over 120 different types of papilloma virus
can infect humans .
- Widely distributed in nature .
-papilloma viruses are 55 nm diameter
, icosahedral , ds DNA viruses and cause skin
papillomas (warts ) and tumors .
- species specific , can be distinct from animal
papilloma viruses .

28. - They show adaptation to definite sites on the
body ,
- At least 40 types including HPV6 , 11 , 16 and
18 can infect the anogenital tract and other
mucosal areas ( sexually transmitted ).
- HPV1 and 4 tend to cause plantar warts.
- HPV2 , 3 and 10 to cause warts on the knees
and fingers.
- Direct and indirect transmission .
- DELETE

29. HPV2 , HPV3
&HPV10 cause
warts on the
knees and
fingers.
HPV1 &HPV4
tend to cause
plantar warts
40 types( HPV6
,11,16&18)
infect the anogenital
tract and other
mucosal areas
(sexually transmitted)
They show
adaptation
to definite
sites on the
body .

30. - Diagnosis: viruses cannot be cultivated
in the lab. , and at present serologic
tests are neither useful nor available
- DNA detection methods

31. Types of genital herpes:
Herpes simplex virus type 1 (oral herpes)
Characterized by lesions or blisters found
on the mouth or lips.
Herpes simplex virus 2 (genital herpes)
Characterized by lesions found on and
around the genital area.
Viral Infections

32. Genital herpes is generally transmitted by sexual
contact. Direct contact with infected genitals can cause
transmission via sexual intercourse, oral-genital
contact, anal intercourse, Other protected areas of skin
can become infected if there is a cut, rash, or sore so that
infections of the fingers, thighs, or other areas of the
body are also possible.
Viral Infections: Genital Herpes

33. The risk of developing genital herpes in a woman
exposed to a symptomatic man is between 80-90%.
A man’s risk of developing genital herpes from a
single sexual encounter with an infected woman is
about 50%.
Problem: Herpes can spread when an
infected individual displays no symptoms!
Viral Infections: Genital Herpes

34. Oral Herpes
Herpes Simplex Oralis

35. The treponemas that infect man are
obligate human parasites
No other natural hosts are known .

36.  Non – venereal diseases
 ( yaws , bejel and pinta )
Venereal disease
( Syphilis )

37. -Intimate physical contact
- contact é infectious body fluids or
- in same instances by fomites

38. -are slender unicellular helical a spiral rods,
motile,é several flagella which do not
protrude into the surrounding medium but
enclosed within bacterial outer membrane .
-Treponemal flagella are complex ,
comprising a sheath and core .

39. -It has a worldwide distribution.
It is the 3rd most frequent STDs in USA
In UK ↑ed 15 – 20 %
-Very sensitive to dryning , heat and disinfectants i–e
the organism does not survive well outside the body .
-Sexual contact .
-Most active age group 15-30 y olds .
-Congenital S ( vertical ) in utero or during delivery .
-S has been rarely acquired by transfusion of infected
fresh human blood .

40. - Outer memb. Ptns are associated é adherence to
the surface of host cells.
-Produce hyaluronidase ẃ may facilitate perivascular
infiltration .
-Spirochetes are coated é host cell fibronectin ẃ can
protect against phagocytosis .
-The cell surface rich in lipid and the antigen are
covered , therefore T.P. can survive in the body for
many years despite avagorous immune response .
- Tissue damage is mostly due to the host response.

41. -Penetration of intact mucosa or through abraded skin
→ local multiplication
( very slow by av.3w )
infiltration of plasma cells ,
polymorph and macrophage.
é endarteritis .
Spread by lymphatics and blood to any organ .
NB.

42. Congenital Syphilis – perforation of palate

43. Secondary Syphilis: Papulo squamous rash

44. Adv. Screening.
Low cost ,
Technical simplicity ,
Monitor the efficacy of the
treatment.
Disadv. False + ve ( acute
viral , bacterial infection
...)
VDRL
RPR
Cardiolipin (Ag) + sera → floccultion
1st (70%) 2nd ( 100%) late ( 0% )

45. Fluorescent treponemal antibody absorption ( FTA –
Abs ) test.
Heated treated serum is 1st absorbed é a suspension of
a non-pathogenic treponema ( ẃ removes non-
specific cross-reactive Abs that may be detected
against commensal spirochates .
1st ( 80% ) 2nd ( 100% ) late ( 95% )
Remains + ve following successful therapy.
NB.

46. - T.P. haemagglutination assay ( TPHA )
Sera are pre-absorbed.
Remain + ve for life .
Important for neuro S.
1st ( 65 ) 2nd ( 100 ) late ( 95 ) .
- T.P. particle agglutination test ( TPPA ).
use colored gelatin particles.
- ELISA or western blot for IgM in cong.syphilis .
- Recently available kits for rapid detection.