Causes of HIV/AIDS

Acquired Immune Deficiency Syndrome (AIDS) is caused by one of two viruses: HIV-1 or HIV-2. 

HIV-1 is the predominant virus in most parts of the world, including South Africa, while HIV-2 is most commonly found in West Africa.

The two HI viruses are retroviruses that insert their genetic material into the DNA of the cells of the person they’ve infected. In this way, they can infect you for the rest of your life, while decreasing your resistance to infections and certain cancers.

The HI virus, which is circular in shape, does something that no other virus does: it attacks your CD4 cells (the most important immune cells in your body), uses them to reproduce, and then destroys them.

The immune system weakens as more CD4 cells are killed, eventually progressing to AIDS.

The choice of antiretroviral treatment (ART) for HIV-2 differs from that for HIV-1, which is why it’s important to get tested properly. ART is designed to interfere with the virus’s ability to reproduce, slowing down the progression of HIV to AIDS.

Symptoms of HIV/AIDS

While it’s impossible to look at someone and know whether they have HIV, the majority of people will have some symptoms about three weeks after they become infected with the virus.

This is called “seroconversion illness” (or primary or acute HIV infection) and coincides with the production of antibodies to the virus. Antibodies are molecules that recognise and attach to organisms invading the body with the aim of destroying them.

HIV antibodies become detectable in the blood during seroconversion, and standard HIV tests (rapid test or ELISA) are used to determine whether they are present. The period after infection, but before the production of antibodies, is called the window period. During this time, an HIV test may be negative.

During the seroconversion illness, symptoms usually last 1–2 weeks and may include the following:

• Fever and night sweats 
• Aching muscles and tiredness 
• Sore throat  
• Swollen glands 
• Diarrhoea 
• Skin rash and ulceration of the inside surface of the mouth and genitals 
• Headache, sore eyes and sensitivity to light 

After experiencing these initial symptoms, most people don’t have any other symptoms for many years. This is why HIV/Aids is often called the “silent epidemic” and why getting tested is so important. Only a blood or fluid sample can reveal the presence of the virus.

When symptoms associated with the advance of HIV to AIDS occur, they appear roughly in the following order:

• Unexplained weight loss (more than 10% of body weight) 
• Swelling of glands in the neck, armpit or groin 
• Easy bruising 
• Recurring and unusual skin rashes (often itchy)
• A thick, white coating of the tongue or mouth (oral thrush) or vagina (vaginal thrush), which is severe and recurs
• Ongoing vaginal discharge and pain in the lower abdomen 
• Sinus fullness and drainage 
• Recurrent herpes 
• Shingles 
• Persistent sore throat 
• Recurring fevers lasting more than 10 days without an obvious cause 
• Night sweats or chills 
• Persistent cough and/or shortness of breath 
• Persistent severe diarrhoea (longer than a month) 
• Changes in vision 
• Pain, loss of control and strength of muscles, paralysis 
• Discoloured or purplish growths on the skin or inside the mouth or nose
• Difficulty concentrating, inability to perform mental tasks that have been done in the past, confusion, personality change

In children, the order of symptoms and the symptoms themselves differ slightly, and include:

• Persistent oral thrush 
• Recurrent bacterial infections (e.g. ear infections)
• Recurrent gastroenteritis 
• Swollen salivary glands (parotitis) 
• Swollen lymph nodes in the neck, armpits or groin 
• Enlargement of the liver and spleen 
• Failure to grow or reach developmental milestones at the right time (e.g. talking or walking) 

HIV is regarded as a chronic disease because people living with HIV can live healthy and productive lives for many years before getting sick.

However, if you’re HIV-positive, you’ll need ongoing monitoring and regular clinic visits to determine the progression of the disease.

The length of time it takes for HIV to become AIDS varies from person to person and depends on your access to treatment, health status and health-related behaviours.

How to Treat HIV/AIDS

HIV/AIDS is treated with antiretroviral treatment (ART) and medication that helps to keep opportunistic infections (diseases that occur in people with suppressed immune systems) under control.

Without treatment, almost everyone with HIV will get AIDS. ART isn't a cure, but it can control the virus so that you can live a longer, healthier life and reduce the risk of transmitting HIV to others.

The goals of ART treatment are to:

• Consistently suppress the viral load (the amount of concentration of HIV in your blood)
• Keep your immune system as strong as possible
• Reduce your risk of HIV-related infections
• Improve your quality of life and make you live as long as possible
• Prevent you from passing the virus on to others
• Minimise the side effects related to your treatment

ART involves taking a daily combination of HIV medicines, called an HIV regimen. These HIV medicines prevent the virus from multiplying (making copies of itself), which reduces the amount of HIV in the body.

Having less HIV in your body gives your immune system a chance to recover and fight off infections and cancers. It also allows you to remain symptom-free for longer. 

ART is recommended for anyone who has HIV, without delay, regardless of how long they’ve had the virus or how healthy they are. If left untreated, HIV will attack the immune system and eventually progress to AIDS.

ART is strongly advised when the CD4 count is less than or equal to 350 cells per mm3, or if you have an AIDS-defining illness, irrespective of your CD4 count.

Certain groups of people, such as children under the age of five, those with HIV and TB and those with HIV and hepatitis, should receive ART as soon as possible. 

If you feel unsure about taking the medicines, talk to your doctor or clinic nurse about your concerns. It might also help to talk to someone else who is using ART.

Factors to consider when starting ART:

• Your medication must be taken for the rest of your life to control the HIV infection. 

• Treating HIV/AIDS usually requires a fairly complex medication regimen. The main first-line regimen (tenofovir/emtricitabine/efavirenz) consists of one single tablet to be taken at the same time every day. For those who aren’t able to take this regimen, or who have failed this regimen, the number of pills increase. Fortunately, more and more combination tablets are increasingly available, which makes taking ART easier. 

• The tablets must be taken at the correct times of day or they won’t work properly. The more doses you miss, the greater the chance of viral mutations and drug resistance, so make sure to take your medication exactly as prescribed. It’s important to not miss doses. Write down exactly how you should take your medicine to help you remember. There’s support available at health facilities to assist with taking pills. Find out from your doctor what this entails. 

• The medicines often have unpleasant side effects such as nausea and headache. Speak to your doctor or clinic nurse if you’re unsure of how to deal with them. 

• It may be necessary to change your treatment over the course of your life. You therefore have to be motivated and dedicated to taking your treatment as directed. Be open and honest with your clinic doctor or nurse. 

• Remember that the virus can never be completely eradicated from your body. A reservoir of infected cells will always remain, even if the virus can’t be detected in your blood. Currently, doctors can only test for 40 virus copies in the blood; if less copies are present, tests won’t pick up the virus.

• Tell someone you trust that you’re on ART. Ask them to remind you to take your medication every day, to join you when you visit your clinic or doctor, and to help you if you experience unpleasant side effects.  

• Tell  to your doctor about your risk for other diseases as a result of taking ART (e.g. diabetes type 2) and find out what you can do to lower your risk.

• Don’t ever skip a clinic or doctor’s visit, and try to go to the same facility every time. The facility will keep a medical record, helping you to track your progress. 

PrEP, PEP and the race to find an HIV vaccine
If you’re HIV-negative but at ongoing risk of being exposed to HIV, it’s worth learning more about pre-exposure prophylaxis (PrEP) and post-exposure prophylaxis (PEP).
You might also be interested to know if researchers are making progress in developing an HIV vaccine.

Pre-exposure prophylaxis (PrEP)
Prophylaxis refers to the prevention or protective treatment of disease. The WHO now recommends that people who are at substantial risk of getting HIV infection should be offered preventative antiretroviral treatment (ART), called pre-exposure prophylaxis (PrEP). 

High-risk groups include sex workers, men who have sex with men, adolescents or adults engaging in condomless sex, or the HIV-negative partners of those who are HIV-positive. A drug called Truvada (a combination of emtricitabine and tenofovir disoproxil fumarate, which is licensed in South Africa for this purpose) can reduce the risk of contracting HIV by at least 90% if taken every day. 

In September 2017, the Higher Education and Training HIV & AIDS (HEAIDS) national programme also announced that Truvada will be made available to university and college students across South Africa. 

If you’re using Truvada to limit your risk of getting HIV, it’s important to use the drug in combination with other safer sex practices (e.g. using a condom). Make sure you still get tested for HIV every three months and talk to your doctor or clinic nurse if you experience any side effects. 

You should also remember that PrEP becomes effective only after 7-20 days of taking the medicine. It takes around 7 days for the drug to reach rectal tissue, and around 20 days for the drug to reach tissues of the cervix and vagina. 

PrEP should be taken for as long as you’re considered “high risk” and must be continued for 28 days after your last potential HIV exposure. It shouldn’t be taken if you think you may be HIV-positive (for example, if you’re still in the window period) or definitely are HIV-positive. Tests will be carried out before starting PrEP to ensure that you’re HIV-negative. 

Post-exposure prophylaxis
In the context of HIV, post-exposure prophylaxis (PEP) refers to ART that’s given to someone to help prevent HIV infection after being exposed to the virus.

Healthcare workers who are accidentally exposed to HIV through, for example, a needle-prick accident, should start taking ART as soon as possible after the incident, but no later than 72 hours after exposure. 

The drugs must be taken for 28 days and you should see your doctor every two weeks, six weeks and three months after the exposure for HIV testing. Tests for hepatitis B and C, as well as syphilis, should also be done. 

PEP isn’t needed if the source patient was HIV-negative. It’s also contraindicated if you’re HIV-positive. If this is the case, you should be on ART.

From analysing thousands of accidental exposures in healthcare workers, it’s been calculated that even though the risk of getting HIV infection from such an accident is quite low (0.3% of cases), taking ART reduces the risk of infection by about 80%.

The South African Government now also funds ART in the context of rape and women who have been raped should start ART as soon as possible.

Note that PEP may be difficult to obtain outside of large hospitals. If you’ve been raped, you can get in touch with a rape centre in your area or ask the local police to point you to a facility where you’ll be assisted. 

A doctor or clinic nurse will assess your risk of HIV infection before starting treatment with PEP. 

The race to find a vaccine
The first HIV vaccine clinical trial kicked off in Maryland, USA, in 1987.

Since then, numerous experimental vaccine trials have been conducted but none have proven effective. The first-ever vaccine to show efficacy was tested during the RV144 trial in 2009. 

The trial consisted of over 16,000 participants in Thailand who received a combination of two vaccines – AIDSVAX and ALVAX. These vaccines were based on HIV strains commonly circulating in Thailand.

A total of six injections were given over six months and participants were followed up for three years. The vaccine lowered the rate of HIV infection by 31% when compared to a placebo. It was the first vaccine trial to appear effective. 

There are two vaccine trials currently running in South Africa: HVTN702 is testing a vaccine to protect against the subtype C HI virus prevalent in southern African populations. The vaccine used in this trial is a modified version of the vaccine used in the RV144 trial.

It started in late 2016 and results are expected in 2020. The HVTN702 trial is a phase III trial, which means that, if successful, the drug qualifies to be licensed for medication.  

A new vaccine trial was launched in 15 sites across South Africa at the end of 2017. The HVTN705 study involves a mosaic vaccine that targets different strains and sub-types of HIV-1.

It will be tested on 2,600 HIV-negative women between the ages of 18 and 35 who are at risk of HIV infection. Results are expected in 2021 but, even if the trial is successful, further studies will be required. It could take several years before a vaccine becomes available.

Other preventative methods on the horizon
Other preventative methods that are in the research pipeline include vaginal rings, gels and tablets that release antiretroviral medication to reduce the risk of getting HIV from others. None of these have been approved for use as yet. 

The US National Institutes of Health (NIH) have also recently launched a trial to test a preventative injection of a drug called cabotegravir. The trial will establish whether a two-monthly injection will reduce the risk of contracting HIV.  

Some 3,200 women in southern and eastern Africa, including South Africa, are participating in the trial. Half of the women will take Truvada, while the other half will receive the injection every few months. The study will run for three years and will then assess which group has fewer HIV infections. 

Classes of drugs
A growing number of drug classes are being used to treat HIV. These drugs work against the virus in different ways and at different points in the growth cycle.