Sexually transmitted diseases (STDs) are caused by pathogens transmitted through sexual contact. Over 20 pathogens can cause STDs, affecting the genital tract and sometimes other sites. Key STDs include gonorrhea, syphilis, chlamydia, trichomoniasis, genital herpes, and human papillomavirus. Factors influencing STD transmission and prevalence include age, sex, marital status, socioeconomic status, high-risk behaviors, and social determinants. STDs are diagnosed through clinical features and laboratory tests and treated through antimicrobial therapies. Prevention relies on education, screening, partner notification, and barrier methods.

2. Sexually transmitted diseases
• The sexually transmitted diseases(STD) are a group of communicable
diseases that are transmitted predominantly by sexual contact and
caused by a wide range of bacterial, viral, protozoal and fungal agents
and ectoparasites.

3. agent
• Over 20 pathogens have been found to be spread by sexual contact.

4. Host factors
(a) Age : For most notifiable STDs, the highest rates of incidence are
observed in 20-25 year-olds, followed by the 25-29 and 15-19 years age
groups. The most serious morbidity is observed during foetal
development and in the neonate.
(b) Sex: For most STDs, the overall morbidity rate is higher for men
than for women, but the morbidity caused by infection is generally
much more severe in women, as for example, pelvic inflammatory
disease.

5. Host factors
(c) Marital status: The frequency of STD infection is higher among
single, divorced and separated persons than among married couples.
(d) Socio-economic status : Individuals from the lowest socioeconomic
groups have the highest morbidity rate.

6. Demographic factors
population explosion and marked increase in the number of young
people, the group at highest risk for STD in the population; rural to
urban migration; increasing educational opportunities for women
delaying their marriage and increasing STD risks.

7. Social factors
Prostitution
Broken homes
Sexual disharmony
Easy Money
Urbanization and industrialization
Social disruption

8. Social factors
International travel
Changing behavioural patterns
Social stigma
Alcoholism

9. Social factors
Numerous social and behavioural factors are involved in the spread of STDs. These
include:
(a) Prostitution : This is a major factor in the spread of STDs. The prostitute acts
as a reservoir of infection
(b) Broken homes : Social studies indicate the promiscuous women are usually
drawn from broken homes, e.g., homes which are broken either due to death of one
or both parents or their separation. The atmosphere in such homes is unhappy, and
children reared in such an atmosphere are likely to go astray in search of other
avenues of happiness.

10. Social factors
(c) Sexual disharmony : Married people with strained relations, divorced and
separated persons are often victims of STDs.
(d) Easy money : In most of the developing world, prostitution is simply a
reflection of poverty. It provides an occupation for earning easy money.
(f) Urbanization and industralization : These are conductive to the type of
lifestyle that contributes to high levels of infection, since long working hours,
relative isolation from the family and geographical and social mobility foster casual
sexual relationships.

11. Social factors
(g) Social disruption : Caused by disasters, wars and civil unrest have always
caused an increase in the spread of STDs.
(h) International travel: Travellers can import as well as export infection and their
important role in the transmission of STD is exemplified by the rapid spread
throughout the world of resistant strains of N. gonorrhoea and AIDS.

12. Social factors
(i) Changing behavioural patterns : In modern society, the value traditionally set on chastity is in
conflict with the more recent ideas of independence, freedom from supervision, and equal rights for
both sexes. There has been a relaxation of moral and cultural values in present-day society. The
tendency to break away from traditional ways of life is particularly marked among young people.
(j) Social stigma : The social stigma attached to STDs accounts for the non-detection of cases, not
disclosing the sources of contact, dropping out before treatment is complete, going to quacks for
treatment, and self-treatment.
(k) Alcoholism : The effect of alcohol seems to be more indirect than direct. Alcohol may encourage
prostitution and conversely, prostitution may boost the sale of alcohol.

13. Clinical Spectrum
• Neisseria Gonorrhoea
Gonococcal infection
• Treponema Palidom
Syphilis
• Chlamydia trachomatis
Chlamydial Infection
• Trichomonas Vaginalis
Trichomoniasis

14. Clinical Spectrum
• Herpes simplex virus
Genital herpes
Human papilloma virus

15. GONOCOCCAL INFECTION
Causes inflammation of the genital tract involving the urethra in men
and women, the cervix and rectum in women, and the rectum in men
who have sex with men. Other sites are the throat (pharyngitis) and the
eyes. The possible complications in women include pelvic inflammatory
disease (PID).

16. PID

17. syphilis
Syphilis causes ulceration of the uro-genital tract, mouth or rectum.
Other signs of this infection, occurring in later stages, range from skin
eruptions to complications of the cardiovascular and nervous system.
Congenital syphilis is an important cause of stillbirth.

19. CHLAMYDIAL INFECTION :
A high percentage of individuals have no obvious clinical
manifestations of this infection. If symptoms occur they are similar to
those caused by gonorrhea.

20. TRICHOMONIASIS
This parasitic infection leads to vaginitis and vaginal discharge in
women. Usually, there are no symptoms. In most men there are no
symptoms but it may cause urethritis.

21. CHANCROID
• Sexually transmitted disease (STD) that results in sores on your
genitals.
• After infection a small papule develops at the site of inoculation,
normally within 2-3 days. The lesion then erodes into a deep ulcer that
is extremely painful. In about 25 per cent of patients there is a painful
swelling of one or the other inguinal lymph nodes (bubo).

23. GENITAL HERPES
• Herpes simplex virus type 2 (HSV-2) is the primary cause of genital
herpes.
• Classical genital herpes can be recognized by the presence of typical
papular lesions that progress to multiple blisters and ulcers.
• However, the features can be variable in many people and the
appearance can easily be confused with other genital infections. HSV-
2 infection is life-long and recurrent ulcerative episodes occur

25. HUMAN PAPILLOMA VIRUS
Human papilloma virus (HPV) causes ano-genital warts, which vary
from the common soft, flesh-coloured protuberances which may become
exuberant (cauliflower like) to papular flat warts on drier areas (eg.
shaft of penis)

27. Acquired immuno-deficiency syndrome
(AIDS)
• AIDS, the acquired immuno-deficiency syndrome (sometimes called
"slim disease") is a fatal illness caused by a retrovirus known as the
human immuno-deficiency virus (HIV) which breaks down the
body's immune system.

28. Acquired immuno-deficiency syndrome
(AIDS)
• Human Immunodeficiency Virus.
• damages the immune system.
• infects and kills CD4 cells
• lifelong condition and currently there is no cure, although many scientists are
working to find one.
• With Antiretroviral therapy, it’s possible to manage HIV and live with the virus for
many years.

29. Problem statement
• In 2021, 650 000 [510 000–860 000] people died from HIV-related
causes and 1.5 million [1.1–2.0 million] people acquired HIV.
• There were an estimated 38.4 million [33.9–43.8 million] people
living with HIV at the end of 2021, two thirds of whom (25.6 million)
are in the WHO African Region.

30. Problem statement
The current targets set by UNAIDS for HIV testing and treatment are
called the 95-95-95 targets and must be reached by 2025 in order to end
AIDS by 2030.

31. Problem statement
• To reach the new proposed global 95–95–95 targets set by UNAIDS,
we will need to redouble our efforts to avoid the worst-case scenario
of 7.7 million HIV-related deaths over the next 10 years, increasing
HIV infections due to HIV service disruptions during COVID-19, and
the slowing public health response to HIV.

32. Agent factors
(a)AGENT : human immune-deficiency virus(HIV) of retrovirus
family.

33. Agent factors
(b) RESERVOIR OF INFECTION : These are cases and carriers.
Once a person is infected, the virus remains in the body life-long. The
risk of developing AIDS increases with time. Since HIV infection can
take years to manifest itself, the symptomless carrier can infect other
people for years.

34. Agent factors
(c) SOURCE OF INFECTION:
• The virus has been found in greatest concentration in blood, semen
and CSF.
• Lower concentrations have been detected in tears, saliva, breast milk,
urine, and cervical and vaginal secretions.

35. Host factors
(a)AGE : Most cases have occurred among sexually active persons aged
20-49 years.
(b) SEX : the sex ratio is equal. Certain sexual practices increase the
risk of infection more than others, e.g., multiple sexual partners, anal
intercourse, and male homosexuality.

36. Host factors
(c) HIGH-RISK GROUPS : Male homosexuals and bisexuals,
heterosexual partners (including prostitutes), intravenous drug abusers,
transfusion recipients of blood and blood products. Higher rate of HIV
infection is found in prostitutes.

37. Mode of transmission
Sexual
Blood contact
Maternal-foetal

39. HIV Transmission
• For every 10,000 blood transfusions from a donor with HIV, the virus
is likely to be transmitted 9,250 times.
• 63 out of every 10,000 exposures to infected shared needles.
• For needlesticks, 23 in every 10,000 exposures.
(Centers FOR Disease Control and Prevention,CDC)

41. Incubation period
• While the natural history of HIV infection is not yet fully known,
current data suggest that the incubation period is uncertain, (from a
few months to 10 years or even more) from HIV infection to the
development of AIDS.

42. Clinical features
Initial infection with the virus and
development of antibodies
1.Asymptomatic carrier state
AIDS-related complex
AIDS

43. Initial infection with the virus and
development of antibodies
 Mild illness (fever, sore throat and rash) for a few weeks
 Most HIV-infected people have no symptoms for the first 5 years or
so .
 They look healthy and feel well although right from the start they can
transmit the virus to others.
 HIV antibodies usually take between 2-12 weeks to appear in the
blood-stream

44. Asymptomatic carrier state
Persistent generalized lymphadenopathy.

45. AIDS-related complex
 Exhibit one or more of the following clinical signs:
 Unexplained diarrhea lasting longer than a month.
 Fatigue, malaise
 Loss of more than 10% body weight
 Fever
 Night sweats
 Other mild opportunistic infections such as oral thrush, generalized
lymphadenopathy or enlarged spleen.

46. AIDS
 End-stage of HIV
 A number of opportunist infection commonly occur at this stage and
or cancers
 Usually seen tuberculosis
 Wasting syndrome (slim disease)
 Chronic diarrhea and severe weight loss
 Herpes zoster

47. Testing for HIV
• ELISA or EIA test
• Western blot test

48. HIV RNA test
• Detect HIV RNA
• Estimate HIV viral load
• Newborn screening of HIV-positive mothers
• Helpful in detecting HIV infection in the first four weeks following
exposure

49. Prevention and control
1.Case detection
1.Case holding and treatment
1.Epidemiological treatment
1.Personal prophylaxis
1.Health education

50. Case detection
• Case detection is an essential part of any control programme.
a. Screening: Screening is the testing of apparently healthy volunteers from the general population
for the early detection of disease. High priority is given to screening of special groups like
pregnant women, blood donors, industrial workers, army, police, refugees, prostitutes etc.
b. Contact tracing: Contact tracing is the term used for the technique by which the sexual partners
of diagnosed patients are identified, located, investigated, and treated.
c. Cluster testing: Here the patients are asked to name other persons of either sex who move in the
same socio-sexual environment. These persons are then screened.

51. Case holding and treatment
• Adequate treatment of patients and their contacts is the mainstay of STD control.
There is a tendency on the part of patient suffering from STDs to disappear or
drop out before treatment is complete. Therefore, every effort should be made to
ensure complete and adequate treatment.

52. Epidemiological treatment
• It consists of the administration of full therapeutic dose of treatment to persons
recently exposed to STD while awaiting the results of laboratory tests.

53. Personal prophylaxis
• Contraceptives: Mechanical barriers (eg. Condoms) can be recommended for
personal prophylaxis against STDs. However, their use is limited by lack of
motivation, acceptability and convenience.

54. Health education
Health education is an integral part of STD control programmes. The principal aim
of educational intervention is to help individuals alter their behavior in an effort to
avoid STDs, that is, to minimize disease acquisition and transmission.

55. treatment

56. treatment

57. Post-exposure prophylaxis
• Short-term use of ARV drugs to help prevent HIV transmission.
• The rationale is that ARVs given immediately after exposure can stop
the virus from disseminating in the body and establishing infection.

58. Post-exposure prophylaxis

59. Post-exposure prophylaxis
• Start as soon as possible, preferably within 2 hours and maximum
within 72 hours of exposure. The duration of treatment is 28 days.

60. Transplacental diseases

61. introduction
• Is an infection caused by pathogenic bacteria or viruses that use
mother-to-child transmission, that is, transmission directly from the
mother to an embryo, fetus or baby during pregnancy

62. Introduction
• “Infections acquired in utero or during the birth process”
• The infected newborn may show abnormal growth, developmental
anomalies, or multiple clinical and laboratory abnormalities.
• Severity depends on the gestational age of fetus at the time of
infection & virulence of the organism
• Timely diagnosis of perinatally acquired infections is crucial the
initiation of appropriate therapy

63. Types of infection
T – toxoplasmosis from Toxoplasma gondii
O – other infections (Syphilis)
R – rubella
C – cytomegalovirus
H – herpes simplex virus-2

64. toxoplasmosis
• Causative Organism: Toxoplasma gondii
• Oocyst excreted in cats feces is the source of infection to humans.
• Contaminates in soil, water & raw meat
• Transmission: Vertical transmission can occur in utero or during
vaginal delivery & risk of fetal transmission is
25% in 1st Trimester
75% in 3rd Trimester
90% during last few weeks prior delivery

65. Clinical features
• Most infected newborns are asymptomatic at birth
Few develop
• IUGR
• Fever
• Maculopapular rash
• Anemia
• Jaundice
• Seizure
• Hepatosplenomegaly
• Thrombocytopenic purpura

66. Clinical features
Classical Triad
1) Chorioretinitis
2) Diffuse Nodular Intracranial calcifications
3) Hydrocephalus

67. management
WHO & CDC Recommends Combination Therapy for standard
treatment of congenital toxoplasmosis
• Pyrimethamine (1mg/kg/day daily for first 6months & 1mg/kg/day
thrice a week for second 6 months)
• Sulfadiazine (100mg/kg/day in 2 divided doses for 1 year)
• Leucovorin (Folinic Acid; 5-10mg thrice a week)

68. Congenital rubella
 Also known as German Measles
 Organism: RNA virus, a member of the Togavirus family

69. Congenital rubella
Transmission:
 Direct droplet contact from nasopharyngeal secretions
 Virus replicates in the lymph tissue of the upper respiratory tract
 Spreads hematogenously across the placenta.
 Maternal infection rate is high, especially at the time of 1st trimester
& last 1 month
Malformation occurs in 90% of infection during 2-10 weeks of
gestation.

70. Clinical features
 IUGR, still birth, abortion
 Jaundice
 Microcephaly, meningoencephalitis
 Blueberry Muffin Rash
 Sensory Neural Deafness
 Congenital heart disease
 Eye defects (cataracts, congenital glaucoma)

71. The risk of maternal-fetal transmission is the greatest in the first 10 days
after gestation

72. diagnosis
ANTENATAL DETECTION
• Specific IgM in Fetal blood obtained by percutaneous umbilical cord
blood sampling.
• Rubella antigen and RNA in a Chorionic villous biopsy specimen.

73. diagnosis
POSTNATAL DETECTION :
 Detection of Rubella Specific IgM below 3months (or) IgG between
6months to 12 months.
 Virus Isolation: pharyngeal secretions/urine sample upto 1 yr

74. prevention
 Girls should be vaccinated against rubella before entering the
childbearing years.
 Rubella vaccine is a live attenuated vaccine which is available
separately or as triple vaccine (MMR) that contain measles, mumps
and rubella.
 Special care should be taken in reproductive females to avoid
pregnancy for 3 months after MMR vaccination.

75. CytomegaloVirus
 Causative Organism: Cytomegalovirus - member of herpes virus
family
 It is the most common cause for Non-Hereditary cause of SNHL
worldwide.
 Transmission:
 Close contact – young children attending daycare center
 Saliva/ Urine/ Blood & Breastmilk
 Route – Transplacental/ Intrapartam/ Postnatal

76. Clinical features
At birth, most infants with congenital CMV are asymptomatic.
Few Develop:
 SGA/Prematurity
 Hepatospleenomegaly
 Microcephaly/SNHL/Seizures
 Petechiae & Jaundice at Birth
 Thrombocytopenia
 Pneumonia

77. diagnosis
Viral isolation from urine or saliva in 1st 3 weeks of life Viral load and
DNA copies can be assessed by PCR.

78. treatment
Ganciclovir x 6wks in symptomatic infants

79. Herpes simplex Virus
Herpes Simplex Virus(HSV) - DNA virus with two virologically distinct
types: 1 and 2
Transmission:
 Contact with genital lesions during delivery: Common
 Transplacental : Rare.

80. Clinical features
 Inutero Infection:
Skin: Scarring, vesicles, hypo/hyperpigmenation
Eyes: Microphthalmia, retinal dysplasia
CNS: Microcephaly, encephalomalacia

81. Herpes simplex Virus
 Intrapartam/Postpartam Infection:
SEM disease : Vesicular lesions, Conjunctivitis, excessive tearing,
Ulcerative lesions of the mouth, palate & tongue
 Sepsis, Fever, Respiratory distress, Skin lesions, CNS involvement(60
to 75%)

82. LESIONS OF NEONATE WITH SEM
DISEASE

83. management
 Acyclovir Therapy- 60 mg/kg/day 3 div doses
 SEM disease : Duration for 14 days
 CNS: Duration for at least 21 days, or longer if the CSF PCR remains
positive.
 Infants with ocular involvement :Topical ophthalmic antiviral agents
in addition to parenteral therapy.

84. prevention
• C-Section for mothers with genital lesions
• Acyclovir for pregnant mothers with primary HSV

85. references
Park, K. (2019). Park`s Textbook of Preventive and Social Medicine.
M/s Banarsidas Bhanot publishers.
Gupta, MC, Mahajan, BK. (2013). Mahajan and Gupta Textbook of
Preventive and Social Medicine. Brothers Medical Publishers (P)
Ltd.
Annual Report, Department of Health Services 2077/2078
https://edcd.gov.np/
National HIV testing and treatment guidelines,2022