Question

• Describe and discuss transmission, pathogenesis, clinical manifestations, treatment and prevention of HIV/AIDS.

Answer 1

TRANSMISSION:

HIV can be transmitted through the exchange of a variety of body fluids from infected individuals, such as blood, breast milk, semen and vagnal secretions.

PATHOGENESIS:

the following are the steps through which interaction occurs

• HIV targets and attaches to CD4 molecule through gp 120 that is present on its envelope. It also uses gp 120 to attach to co receptor.HIV needs to bind to both CD4 and co receptor to enter into a host T cell. the most common co receptors HIV uses are CXCR4 present on T cells or CCR5 co receptors which is found on T cells, macrophages,monocytes and dendritic cells.
• After entering the cell, HIV uses an enzyme called reverse transcriptase to convert its single stranded RNA into double stranded proviral DNA that integrates with host's DNA and then transcribes to new viruses and then they leaved the infected T cell and enters into another T cells thus weakening the host immune system,
• Immunodeficiency leads to susceptibility to various infections, tumours .
• The most advanced HIV infection is Acquired immunodeficiency syndrome which can 2-15 years to develop depending on the individual.

CLINICAL MANIFESTATIONS:

The first few weeks after the initial infection individuals may experience NO symptoms or experience flu like symptoms including fever rash, headache or sore throat.

as infection progressively weakens the immune system the individual can develop other signs and symptoms such as swollen lymph nodes, cough , diarrhea and weight loss.

if left untreated , they could also develop tuberculosis, cryptococcal meningitis ,cancers such as lymphomas , kaposi's sarcoma and other diseases.

TREATMENT:

HIV can be supressed with the use of anti retro viral drugs usually a combination of 2 or 3 classes of anti retrovirals.

the following are he classes of anti retrovirals based on their mechanism of action.

inhibit HIV fusion into host cells - Maraviroc, Enfuvirtide.

inhibit reverse transcriptase - abacavir, lamivudine, zidovudine, tenofovir, efavirenz.

inhibit HIV integration into host genome -raltegravir.

zidovudine is safely used in pregnant women and infants at risk.

PREVENTION:

Individuals can reduce the risk of HIV by limiting the exposure to risk factors.

male and female condom use.

using sterile equipment sch as needles, syringes.

Testing for HIV and STD'S

using antiretrovirals by the HIV-Positive person reduces the risk of transmission to his /her uninfected sexual partner by 96%

W.H.O recommends pre exposure prophylaxis for people at substantial risk of HIV infection

post exposure prophylaxis is the use of anti retro viral drugs within 72 hours of exposure to HIV to prevent the infection.