STD

 Sexually transmitted diseases STD

STD are a group of communicable diseases that are transmitted predominantly by sexual contact. STD are very common. The most widely known are gonorrhea, syphilis and AIDS but there are more than 20 others. WHO estimates that every year there are > 330 million new cases of curable STD. About 1 million infections occurring every day.
Aetiological classification of STDs:


Syndromic classification of STDs

Syndromic management of STD, using the flow-charts. It offers many benefits:
All trained 1st line service providers can diagnose and treat patients with STD
Deliver comprehensive care to patient by following all instructions in the chart.
Management of partner.
Health education (safe sex)
Syndromes & the STD causing them:
SyndromeCause of STDUrethral discharge (men)Gonorrhoea
Chlamydial infectionVaginal dischargeTrichomoniasis
Bacterial vaginosis
Candidiasis
Gonorrhoea
Chlamydial infectionUlcer/sSyphilis
Chancroid
Donovosis (granuloma inguinale)Lower abdominal painGonorrhoea
Chlamydial infection
Anaerobic bacteria



HIV / AIDS
Spectrum of diseases caused by HIV infection. Its 1st recognized 1981.
CFR of untreated AIDS is 80 -90 %.
Depletion of T-helper lymphocytes (CD4).
No vaccine has developed & fully tested yet (under trials).
Diagnosis: Clinical
Serological:
HIV AB detected within 1 -3 months after infection by EIA, ELISA and Western blot test. This gap time called window period (i.e from infection and before detection of AB). Some time we repeat test for conformation.
Virus isolation.
CBP:
Lymphopenia, CD4 ↓↓ (normally 800 / mm3), when decrease below 200 / mm3 → prone to opportunistic infections. So CD4 count helps to predict course of disease.
Anemia, Thrombocytopenia, ↑ ESR .
Infectious agent: Human immunodeficiency virus (HIV). A retro-virus, HIV-1 and HIV-2.
- HIV-2 less pathogenic, slower disease progression and lower rates of mother to child transmission.
3. Occurrence:
December 2016: Prevalence 36.7 million HIV / AIDS.
Incidence 1.8 million new HIV infection,
95% of new cases in developing countries.
AIDS deaths 1.0 million.
≈ 40 million deaths since 1981.
4. Reservoir: Humans.
5. Mode of transmission:
HIV is transmitted by:
Sexual rout – Most common (homo, heterosexual, vaginal, anal or oral sex).
Blood &blood products.
Mother to her child (intrauterine, labor and milk).
HIV is not transmitted by:
Causal contacts as in work, schooletc.
Hand shaking &touches, Sneezing &coughing.
Insects, Food /water &cups /spoons.
Bathes /lavatories & Swimming pools.
Second hand clothing & Telephones.
The virus found occasionally in saliva, tears, urine and bronchial secretion but transmission is not reported after contact with these secretions. Only the blood and semen transmit the virus.
Blood: Whole blood, platelets, factor 8 &9, plasma. No evidence of risk for albumin and immunoglobulin.Risk of transmission from infected one pint of blood is > 95% and its dose related.Risky sexual behaviors:
The risk of transmission of HIV via sexual intercourse is much lower than other STD.
Every single act of unprotective intercourse with HIV infected person → 1 % risk of infection to the partner, however this risk increased by:
Presence of other STD especially ulcerative types as chancroid → 2-5 times,syphilis → 3-9 times.
Gender: Male → female twice than female → male due to higher concentrations of HIV in semen than vaginal secretions & larger vaginal surface area.
Age of uninfected partner:
Female > 45 years → high risk due to thin mucosa.
Adolescent girls high risk due to less effective cervix barrier.
High risk in very early (window period) & very late infections. Because level of virus in blood is higher than other times.
Low risk in circumcised males (8 folds in uncircumcised).
Type of sexual act: anal sex → higher risk → abrasions / trauma. Prostitutes, homosexual male, multiple sexual partners, also sexual act during menstruation.
Vertical
Placenta and during delivery → risk 15 – 30%. With prolonged breast feeding the risk increases to reaches 45%. Rx of infected pregnant with zidovudine → marked decrease of infant infection. Risk increase in early & late infections &when there is crakes in the nipple, prematurity (<34W), maternal anemia and chorioamnonitis.


6. I.P: variable.
HIV → AIDS < 1 year – 15 years or longer. In infants shorter I.P than adults.
7. Period of communicability:
Unknown, early after onset of HIV infection → through out life.
8. Susceptibility: general + risky behavior.
9. Method of control:
A- Preventive measures:
HIV/AIDS prevention programs can be effective only with full community and political commitment to change and/or reduce high HIV-risk behavior.
Health education of public and schools.
Avoid extra marital sexual intercourse, otherwise use condoms.
Adequately sterilization of syringes and needles and lancets, use disposable equipment whenever possible, wear gloves, eye protection and other protective equipment.
In blood bank, all donors should be tested for HIV AB; reject all donations from risky persons.
B- Control of patient, contacts and environment
Reporting: is obligatory in most of countries.
Isolation: for HIV +ve individuals is unnecessary, ineffective and unjustified.
Universal precautions to prevent exposures to blood and body fluids for all hospitalized patients.
Disinfection: of equipment contaminated with blood or infectious body fluids.
Quarantine: not applicable.
Specific treatment:
Prophylactic Rx of P. carinii pneumonia by methoprim. Check for TB infection.
Antiretroviral treatment (ARV): complex, combination of drugs, drugs are toxic and treatment must be for life. It suppresses viral replication and start the Rx aggressively.
Protease inhibitor + two non-nucleoside reverse transcriptase inhibitor started initially.
Post exposure prophylaxis after accidental exposure to blood → (zidovudine + lamivudine) 4weeks.
HIV and TB
TB is one of the opportunistic infection in AIDS patients
No conclusive data indicate that any infection, including M. tuberculosis, accelerate progression to AIDS in HIV infected persons.


Gonorrhea
Almost always STD. 45% of gonorrhea patients has also chlamydial infection.
Male → purulent discharge from urethra, orchitis, epididymitis, proctitis, urethral stricture → sub-fertility.
Female → 80 – 90 % asymptomatic (source of infection), only 10% vaginal infection → discharge, bartholinitis, cervicitis → 20% uterine endomateritis and salpingitis, pyosalpinx → sub-fertility.
I.P: 2 -5 days. No immunity after infection.
Remain infectious for months if untreated.
Effective treatment ends communicability within hours.
Treatment: Ciprafloxacine 5oo mg single dose or spectinomycine 2 gm IM single dose
+ Doxycycline 100 mg / twice/ 7 days or erythromycine 500 mg *4 / 7days.
 Non-specific urethritis (non-gonococcal urethritis) NSU
Causes:
Chlamydial infection 50 60 %.
Ureaplasma urealyticum 10-20%.
Herpes virus-2 rare.
T. vaginalis rare.
Unknwon 30%.

Chlamydial infection

It's an obligate intracellular bacterium, sensitive to broad spectrum antibiotics.

STD and non-STD chlamydial infection:

C. trachomatis:
Trachoma (non-STD) serotypes: A, B, C.
Genital infection (NSU in male and cervical infection in female) same presentation as G.C.
C. conjunctivitisserotypes: D – K.
Infant pneumonia.
Lymphogranuloma venerrum (other serotype L1, L2, L3).
C. pneumoniae → pneumonia (non-STD).
C. psittaci → Psittacosis (non-STD).









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Community Med. Depart.

October 2017

Viral infections

HIV
Hepatitis B virus
Herpes simplex v 1 or 2
Human papiloma HPV (genital and anal warts)
Molloscum contagosum
Chlamydial infections
Chlamydia trachomatis
Fungal infection
Candida albicans
Ectoparasites
Pediculosis
Sarcoptes scabiei (scabies)


Bacterial infections
N. gonorrhoeae (G.C)
T. pallidum (syphilis)
H. ducreyi (chancroid)
Ureaplasma urealyticum
Group B streptococci
Calymmatobacterium granulomatis (donovosis)
Mycoplasma hominis (vagnosis, salpingitis)
Protozoal agents
Trichomonus vaginalis
Entamoeba histolytica
Giardia lambia