Essay on some Major 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.
During the past two decades, STDs have undergone a dramatic transformation. First, the change in name from venereal diseases (V.D) to sexually transmitted diseases (STD) indicates this transformation.
AIDS:
Acquired: Must do something to get it.
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Immune: Ability to fight off infectious agents.
Deficiency: Lack of
Syndrome: Cluster of symptoms that are characteristics for a disease.
AIDS is a chronic life threatening disorder which damages the human body’s immune system. It is characterised by reduction in the number of helper T-lymphocytes because of infection of HIV. Earlier virus was named variously as HCLV III (human cell leukemia virus HI), HTLV HI (human T-lymphotrophic virus III), LAV (lymphadenopathy associated virus) and ultimately HIV.
HIV (Human Immune Deficiency Virus):
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HIV is a part of a family or group of virus called Lentivirus (slow acting virus). The virus which causes HIV belongs to retrovirus (group of RNA virus) which are infectious particles consisting of an RNA genome packaged in a protein capsid, surrounded by a lipid envelope.
This lipid envelope contains polypeptide chains including receptor binding proteins which link to the membrane receptors of the host cell, initiating the process of infection.
Retroviruses contain single stranded RNA as the hereditary material in place of the more common DNA. In addition to RNA, retrovirus particles also contain the enzyme reverse transcriptase (or RNAse), a multifunctional enzyme, which causes synthesis of a complementary DNA molecule (cDNA) using virus RNA as a template.
Difference between HIV and AIDS:
HIV (Human Immunodeficiency Virus) damages or destroys the cells of the immune system making the body less able to fight infections, and more susceptible to life threatening opportunistic infections.
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AIDS (Acquired Immunodeficiency Syndrome) refers to the latter stages of HIV infection. Most individuals infected with HIV will progress to AIDS if not treated; however, there are very small numbers of patients who develop AIDS very slowly or not at all.
Mode of transmission:
The HIV virus can only survive in body fluids like blood, semen, vaginal secretion etc.
HIV is transmitted through body fluids by:
Sexual contact with an HIV infected partner (it account for 75% of infection).
Infected blood
Shared needles, syringes, shaving razors contaminated with infected blood
Mother to child (during child birth or breast-feeding)
In rare cases the virus may be transmitted through organ or tissue transplants, artificial insemination through donated semen, or un-sterilized dental or surgical equipment.
HIV is not transmitted through ordinary contact (hugging, dancing, sneezing, talking, touching, or shaking hands) with someone who has HIV or AIDS; sweat, tears or saliva, or through sharing food, utensils, towels, bedding, a swimming pool, telephone or toilet seat with someone who has AIDS; bedbugs or mosquitoes.
It is important to realise that infection with the HIV virus does not necessarily result in AIDS. As with other diseases, some people remain symptomless and are, therefore, termed ‘carrier’.
Symptoms:
Once the HIV virus has entered the body, the immune system comes under attack. The HIV virus multiplies and slowly begins to destroy the CD4 lymphocytes (T-cells or helper T-cells), which are the white blood cells responsible for the coordination of the entire immune system.
The immune system gets progressively weaker over time and becomes susceptible to opportunistic infections (Infections that take advantage of weakness in the immune defenses are called opportunistic infections). The symptoms of HIV and AIDS vary depending on the phase of infection.
Initial infection with the HIV virus may produce no symptoms. The length of time between initial HIV infection and the development of AIDS (called window period) varies greatly, and some people may remain without symptoms for years. Even if a person does not have symptoms, the virus can still be transmitted to others.
It is common to develop a brief flu-like illness 2 to 6 weeks after being infected and the production of antibodies. The symptoms may include fever, headache, sore throat, swollen lymph glands, and rash.
These symptoms are similar to many other diseases and may go unrecognized as HIV infection. Many people remain symptom free for 8 or 9 years, but, during this time the virus continues to multiply and destroy immune cells.
During the last phase of HIV, which can occur up to 10 or 11 years after the initial infection, the immune system has been severely damaged, making the body highly susceptible to a large number of bacterial, viral, fungal and parasitic (opportunistic) infections.
The following may be taken as warning signs of HIV infection, but cautions that any of these symptoms can be related to other illness, and that only an HIV blood test can be used for an accurate diagnosis:
i. Shaking chills or fever higher than 100 F for several weeks and pneumonia
ii. Soaking night sweats
iii. Dry cough and shortness of breath
iv. Chronic diarrhoea that last for more than a week
v. Persistent white spots or unusual lesions on the tongue or in the mouth
vi. Persistent headaches
vii. Blurred and distorted vision
viii. Rapid weight loss
ix. Persistent, unexplained fatigue
x. Swelling of lymph nodes for more than 3 months.
xi. Memory loss, depression, or other neurological disorders.
People with HIV infection are also at greater risk of developing certain cancers, especially Kaposi’s sarcoma, cervical cancer and lymphoma.
Children who are HIV positive often fail to gain weight or grow normally. As the disease progresses, they may have difficulty in walking or delayed mental development.
They may also develop cerebral palsy. In addition, children are susceptible to the same opportunistic infections as adults and may have severe forms of cofnmon childhood illnesses such as ear infections (otitis media), pneumonia, and tonsillitis.
Aids:
The symptoms of AIDS are primarily the result of infections, (called opportunistic infections, OIs) that do not normally develop in individuals with healthy immune system. Getting a 01 is not the same thing as having AIDS.
In order for a patient who is infected with HIV to have AIDS, the immune system must be severely damaged. The severity of the immune system damage is measured by a CD4 lymphocyte count. (Normal CD4 lymphocytes count ranges from 600/ml to 1000/ml).
Most serious form of AIDS is known as AIDS-related complex (ARC) which is characterised by swollen lymph nodes, fever, night sweats and weight loss. 25% ARC patients may develop full blown AIDS.
Diagnostic test:
(i) ELISA (Enzyme-linked immunosorbent assay)
(ii) Western blot test
(iii) Viral load test
Treatment:
There is no cure for AIDS at this time. However, there are several treatments available that can delay the progress of HIV and improve the quality of life of those who have developed symptoms.
1. Antiretroviral therapy:
This is the main type of treatment for HIV and AIDS. The treatment consists of drug which works against HIV infection itself by slowing down the growth and replication of HIV at various stages of life cycle of virus.
The drugs are often referred as anti retroviral, anti HIV, antiviral drugs or HIV antiviral drugs.
2. Highly Active Anti-Retroviral Therapy (HAART):
A combination of three or more antiretroviral agents, called Triple Therapy or Highly Active Anti-Retroviral Therapy (HAART), has been highly effective in reducing the number of HIV particles in the blood stream (as measured by a blood test called the viral load) and as a result increase the CD4 count.
The aim of treatment is to achieve maximum suppression of symptoms for as long as possible.
New Treatment:
The vaccine to be tested is Modified Vaccinia Ankara (MVA). It is a harmless version of the one used for the small pox virus and has been developed to resist the subtype C-HIV strain, which is most common.
The vaccine would help to deliver pieces of the virus, incapable of assembling into a whole virus in the body but efficient enough to develop an immune response.
Diarrhoeal Diseases:
Diarrhoeal diseases are group of infections of the intestinal tract. It is characterised by food poisoning, abdominal cramps, frequent passage of stool having blood & mucous leading to dehydration.
Bacterial diarrhoea:
Bacteria causing diarrhoeal diseases are E.coli, Shigella sp., Campylobacter & Salmonella.
Viral diarrhoea:
Rotavirus causes gastroentritis with acute watery diarrhoea in infants & children.
Norwalk virus causes gastroentritis in all age groups.
Protozoal diarrhoea:
Giardia intestinalis causes giardiasis.