Sexually Transmitted Diseases

• Fertilization involves the fusion of haploid male and female gametes to form diploid zygote.
• Three days is required for an ovum to travel down the oviducts to the uterus. An oocyte lives, however only about 24 hours after its liberation from the follicle.
• During copulation the continued stimulation of the glans penis triggers the spasm of muscles of the genital organs creating the orgasm and resulting in the discharge of semen from the urethra.
• When semen is deposited within the vagina, the spermatozoa are deposited high up in the vagina close to the cervix. Spermatozoa remain viable in the female genital tract for 24–72 h.
• The sperms tend to move in all directions, but many find their way up the cervix of the uterus. They reach the top of the fallopian tube within 5 mm of their release due to contractions in the walls of uterus and fallopian tube where they meet the descending ovum.
• When sperm reches in the oviduct, near the ovum then it releases enzymes to dissolve the egg membrane. Now, the sperm nucleus enters in the egg nucleus to form zygote. This fusion of male and female gametes is known as fertilization. The zygote is formed if copulation has taken place during ovulatory period (middle of menstrual cycle). Fertilization is marked by the absence of menstrual flow.

ARTIFICIAL INSEMINATION:

•  It is a technique to make a female pregnant by artificially introducing semen into vagina.
•  In this process semen from a good quality male is collected, preserved by freezing and used when required.
•  In case of humans it is also being used for improving the chances of fertility.
•  A man may be infertile due to insufficient number of sperms, weak or premature ejaculation, inability of penis to undergo and enter the vagina or non-motile sperms.
•  In this case husband's semen is collected, concentrated and introduced artificially into the wife's vagina. This is called as artificial insemination.
•  If the husband's sperms are faulty, some donor’s sperm can be used. This is called as artificial insemination donor.

Artificial insemination has following two advantages:

• Semen of good quality male animal is used to inseminate a number of females.
• Preserved semen can be transported to distant places, excluding the need for sending the male animal there.

Human Population

Human population growth is supported by life capacity of the environment. Life supporting capacity of environment has been increased many fold by advancements made in science and technology like mechinization of agriculture, use of disease free hybrid and high yielding varieties of seeds and use of fertilizers and pesticides etc. The major causes that have contributed towards increase in the human population are : Decline in death rate, control of diseases, decrease in infant mortality, better sanitation and community health schemes and lastly better means of transport.

Not only these, there are many other socio-economic reasons (e.g. signs of national strength, religious and economic beliefs; signs of security in old age; more earning hands in family etc. that have led to an increase in the human population.

Method of control of overpopulation

Education : People, particularly those in reproductive age group, should be educated about the advantages of a small family and ill-effects of large families and overpopulation. In this, mass media like radio, television, newspapers, magazines, posters etc. and educational institutions can play important role. Government should provide free and compulsory primary education to the children below the age of 14 years. In China, there is a legislation making “basic primary education free, compulsory and universal.”.

Age of marriage : should be raised. Demographers explain that postponment of female marriage age from 18 years to 20 or 22 years would bring down the birth rate by 20 to 30%. Even a years postponment in each age group will decrease total fertility rate much less than the present 3.5% for the country. But according to an ICMR report, about 49% women in India are married before the legal age of 18 years.

Population Control

The prevention of pregnancy in a woman is called contraception. Any device or chemical which prevents pregnancy is called a contraceptive. All the birth control methods are divided into:

•  Barrier methods
•  Chemical methods
•  Intra uterine contraceptive device (IUCD)
•  Surgical methods

Barrier methods:

These are the physical devices to prevent the entry of sperm so that it does not reach the egg. e.g. condoms which can be used to cover the penis. Coverings like diaphragm worn in the vagina can serve the same purpose. Barrier methods also protect against STD’s (sexually transmitted disease).

Chemical methods:

(a) Oral pills: They are hormonal preparations. They act by changing the hormonal balance of the body, so that eggs are not released & fertilization cannot occur. They are taken orally, therefore commonly called oral contraceptives (OC). These pills can cause side effects.

(b) Vaginal pills: They contain spermicides and therefore they kill the sperms.

Intra-uterine contraceptive device (IUCD):

They are contraceptives such as a loop or the copper-T placed in the uterus. They prevent implantation in the uterus. They can cause side effects due to irritation of the uterus.

Surgical methods:

(a) Vasectomy: In males, a small portion of vas deferens (sperm duct) is cut and the cut ends are then ligated (tied). This prevents the sperms from coming out.

(b)Tubectomy: In females, a small portion of fallopian tubes is cut & the cut ends are then ligated (tied). This prevents the egg to enter the fallopian tube.

Surgical methods are the permanent methods of contraception.

SEXUALLY TRANSMITTED DISEASES (STDS)

Sexually transmitted diseases (STDS) are those infectious and communicable diseases which are transmitted from an infected person to a healthy but susceptible person during unprotected vaginal, anal and oral sexual contact. These are generally acquired diseases and usually affect the reproductive system of the person but may spread to other body parts as well.

Increasing resistance in the pathogens to antibiotics. So STDS are easier to avoid than to treat and cure. Absitence, monogamy and the use of condoms are the best ways to avoid STD infections. STDS are also called international diseases.

Gonorrhoea (bacterial disease)

• Syphilis (bacterial disease)
• Warts (viral infection)
• AIDS (viral infection)

AIDS: It is caused by HIV- Human immuno deficiency virus. This disease weakens the body’s immune system so that body becomes weak & cannot protect itself against infection.

Causes :Acquired Immunodeficiency Syndrome (AIDS or aids) is caused by the Human Immunodeficiency Virus, or HIV.

Epidemiology :

• It is a sexually transmitted diseases as it can pass from one person to another during sexual intercourse.
• HIV gradually reduces the efficiency of the human immune system, it destroys the body’s ability to fight diseases. This makes the body vulnerable to other life-threatening diseases that finally cause the patients’s death.
• Once a person is infected, the virus remains in the body life-long. Since HIV infection can take many years to manifest itself, the carrier (who is symptomless) can infect other persons for years.
• HIV attacks the helper T-lymphocytes (or T4 cells–a type of leucocyte). The body is unable to fight infections.
• The patient easily catches infections such as pneumonia and often develops various forms of cancer.
• Incubation period is uncertain, varying from a few months to 10-12 years.

Symptoms

• Short flu-like illness. Chronic diarrhoea and severe weight loss.
• Swollen lymph nodes. Decreased count of blood platelets causing blood loss.
• Development of a disfiguring form of skin cancer (Kaposi’s sarcoma). Sweating at night.
• Severe damage to brain, leading to loss of memory and ability to think and speak.
• Due to breakdown of immune system, the victim becomes susceptible to other infections.

Transmission

The disease is transmitted from an infected person to a healthy person through :

• Sexual contact and infected blood contact, (blood transfusion) are common means of transmission.

• Use of contaminated needles, syringes, blades or razors.

• Through cuts and wounds during close contact between infected and non-infected people.

• From infected mother to foetus through placenta and through breast feeding.

• Homosexual relationship and sharing of needles for drug abuse are high risk groups

Gonorrhoea

Cause :It is a bacterial (gram negative) and veneral (sexually transmitted) disease caused by a diplococcus bacterium, Neisseria gonorrhoea.

Epidemiology :It is a sexually transmitted disease spread by sexual contact with infected persons. The risk of infection depends upon number of exposures.

Incubation period :About 2 to 10 days.

Symptoms :Gonorrhoea is characterised by inflammation of mucous membrane of urinogenital tract so the patient feels burning sensation during urination. The symptoms are more obvious in males than in females. It may also cause arthritis, female sterility and gonococcalophthalmia (eye infection in the children – also called ophthalmianeonatorumwhen contact during its passage through the birth canal).

Prophylaxis :Avoiding prostitution and homosexuality. Identifying the asymptomatic individuals which form high risk group. Health education and use of condoms.

Therapy :Recommended antibiotics are ceftriaxone (most effective), ampicillin and penicillin.