HIV/AIDS awareness

In 2009, the World Health Organization (WHO) estimated that there were 33.4 million people worldwide living with HIV/AIDS, with 2.7 million new HIV infections per year and 2.0 million annual deaths due to AIDS

Acquired immunodeficiency syndrome (AIDS) is a disease of the human immune system caused by the human immunodeficiency virus (HIV). This condition progressively reduces the effectiveness of the immune system and leaves individuals susceptible to opportunistic infections and tumors.

Modes of transmission

HIV is present in blood, semen and other body fluids such as breast milk and saliva. Exposure to infected fluid leads to a risk of contracting the infection, which is dependent on the integrity of the exposed site, the type and volume of body fluid and the viral load. 

Modes of spread

• Sexual contact: man- to- man, heterosexual and oral
• Parenteral: via blood or blood product recipients, drug-users with infected needles, and health care workers with occupational injury
• Vertical:  from a HIV positive mother to her newborn during delivery.

Diagnoses of HIV/AIDS

HIV is most commonly diagnosed by testing of blood for the presence of antibodies to the virus. HIV tests are usually performed on venous blood. Many laboratories use fourth generation screening tests which detect anti-HIV antibody (IgG and IgM) and the HIV p24 antigen. The detection of HIV antibody or antigen in one’s blood shows that the individual have been infected with the HIV virus.

Treatment

The national guidelines for public sector use of HAART are based largely on the WHO 2002 guidelines which states that:

Medical indications for initiating HAART in adults:

1. CD4 count< 200 10^6/L
2. Severe HIV disease (WHO stage 4 disease) irrespective of CD4 stated that the psychosocial indicators for drug readiness are in place.
3. Pregnant women with CD4 less than 350 10^6/l for lifelong ART and CD4 >350 10^6/l for prophylaxis
4. TB patients with CD4 less than 350 10^6/l

Psychosocial indicators include

• It is essential that the patients have good insight into the need for long-term therapy and high levels of adherence
• Structures need to be in place to provide adherence support for patients
• Patients should be encouraged to disclose their HIV status to somebody close to them and this person should act as a treatment supporter.
• HAART should not be commenced if there is active substance abuse or depression.

Antiretroviral therapy consists of three or more antiretroviral drugs that are capable of suppressing HIV replication when usedin combination. The usual HAART regimen contains two nucleoside reverse transcriptase inhibitors together with a non-nucleoside reverse transcriptase inhibitor or a protease inhibitor.

Regimen 1

Consists of two nucleoside reverse transcriptase inhibitors:

• Stavudine (40mg per os 12 hourly) and lamivudine (150mg per os 12 hourly)

Plus

A non-nucleoside reverse transcriptase inhibitor

• Efavirenz (600mg nocté per os) or Nevirapine (200mg per os 12 hourly)

Efavirenz and Nevirapine are equipotent, but have different toxicities. Efavirenz is teratogenic and should not be used in women of child-bearing potential.

In addition:

• Tenofovir 300mg once daily.

It is very important that all patients starting on tenofovir should have their kidney functions tested and followed up, since kidney disease is a contra-indication to tenofovir use.

Regimen 2

Consists of two alternative nucleoside reverse transcriptase inhibitors:

• Zidovudine (300mg per os 12hourly) and didanosine (400mg daily on an empty stomach)

Plus

A protease inhibitor

• Lopinavir/ritonavir combination 400/100 (3capsules 12hourly per os)

Treatment efficacy monitoring

Treatment efficacy is monitored by measuring the CD4 and viral load every 6 months. The viral load will indicate when resistance is developing and when regimens need to be changed. The viral load should become lower than the detectable limit  within        6 months. If this does not happen on the first regimen then this is nearly always due to poor adherence, switching to the second line regimen is only considered when there is a viral load >5000 copies/ml. The CD4 varies more, but usually increases with average 150 cells in the first year. 

Important side effects of antiretroviral therapy includes

• ARV treatment causes a lot of side effects, some more serious than others. Constitutional symptoms such as general malaise, body pains, nausea, vomiting, abdominal discomfort and dyspepsia are very common. Other more complicated and serious side effects are:
• Hyperlipidaemia-Protease inhibitors are known to cause dyslipidaemia, resulting in raised LDL cholesterol and triglycerides. Statins should not be used to treat the side effect of  this drug, as protease inhibitors inhibit the metabolism of most statins resulting in extremely high levels, instead they can be treated with a fibric acid derivative e.g. bezafibrate, oral 400mg nocté.
• ??Hyperlactataemia- is a very serious complication occurring in 1-2% of all patients on long-term NRTIs. The incidence decreasing with the use of stavudine and zidovudine as compared to didanosine. Clinical symptoms of hyperlactataemia are very non-specific, they include nausea, vomiting, abdominal pain, weight loss, malaise with tachycardia. Thus a very high level of suspicion is needed for diagnosis and appropriate management. Depending of the level of lactate, patients can be treated either with an alteration in HAART regime or if more serious, hospital admission and IV Vitamin therapy.
• Anaemia
• Peripheral neuropathy- patients often complain of burning feet. This should be treated with pyridoxine 25mg daily per os, and if more severe with amitryptilene nocté per os.

Conclusion

Without treatment, the net median survival time after infection with HIV is estimated to be 9 to11 years, depending on the HIV subtype, compared to a patient on treatment, having a reduced death rate of 80% and a raised life expectancy for a newly diagnosed HIV-infected person to about 20 years.