What is Human Immunodeficiency Virus (HIV)?

HIV is the abbreviation for Human Immunodeficiency Virus. It is a RNA virus that infect human cells namely CD4 cells. The virus is capable of living in human cells by adapting into DNA particles by a process mediated by the enzyme transcriptase. Following this the virus particles causes cell death. The continuation of the cycle of invasion and death of CD4 cells lead to deficiency of CD4 count and reduce the ability of the human body to fight and eradicate infection.

HIV infection is the cause for Acquired Immune Deficiency Syndrome (AIDS). AIDS develops after a long infection of HIV. The reduction of CD4 count makes the body susceptible to infection that is usually easily eradicated if the immune system is competent. Mild infection in HIV patients with AIDS becomes severe and may lead to death.

Protozoan and fungal infections that are usually easily overcome by a normal person can be severe enough that could lead to death in AIDS patients. HIV infection may also cause a type of skin cancer. People with high risk behaviour are at risk of HIV infection. However anyone is at high risk of HIV infection if exposed to the virus. Children and foetus are also susceptible to HIV infection.

United Nation AIDS / World Health Organization (UNAIDS / WHO) in 2018 reported in the AIDS Epidemic Updates estimated 37.9 million suffer from HIV infection1 worldwide. In the same year UNAIDS / WHO announced an estimated 770,000 people with HIV died of AIDS.

HIV 2 infection is common in the West African countries. However, in other parts of the world HIV 1 infection is more common. HIV 1 infection is more severe compared to HIV 2 infection.

In 2016 Malaysia has registered 111,916 people living with HIV2. Out of 3,397 new cases of HIV population, 71% are adults age 20-39 years. Majority are male. In 2016, 413 women were newly diagnosed with HIV.

What happens when someone is infected with HIV?

HIV infects CD4 cells. CD4 cells are essential for our body’s immune system competency. As HIV infection becomes more severe, the numbers of CD4 cell count declines significantly. The immune system is unable to protect the body from trivial infection and worse off with severe infection. Replication of HIV uses a lot of the body’s energy and affects the function of other cells too. AIDS develops when the CD4 count goes below 200 and patient will manifest a spectrum of clinical conditions and death will ensue subsequently⁴. Opportunistic infection may be caused by bacteria, viruses, fungi and parasites that are normally controlled by the immune system. Which infections occur partly depends on what organisms are common in the person’s environment⁵. These infections may affect nearly every organ system.

How is HIV transmitted?

HIV infection occurs when there is direct exposure of the virus to body fluids. Examples of body fluids are blood, semen, vaginal mucus, breast milk, saliva and open wound on the skin. HIV is transmitted into another person when it is in direct contact with any of this bodily fluid before it infect CD4 cells.

In Malaysia, most common mode of transmission is through homosexuality, followed by heterosexuality. Transmission through sharing of infected needles among intavenous drug users had dropped from 66% in 2005 to 11% in 2016. This is due to the introduction of Needle Syringe Exchange Program (NSEP) in 2006.

In some individuals who was recently infected with HIV, the test for HIV may not be positive until 6 months or longer. This is because the HIV infected persons may take 6 weeks to 3 months or  months to develop antibodies to HIV. During this time, these people can be highly infectious but they are not aware of their condition. This is known as the ‘window period’.

Risk factors for HIV infection

Risk factors for HIV infection are :

• Sharing infected needles
• Multiple sexual partner (promiscuity)
• Homosexuality
• Bisexuality
• Breastfeeding
• Mother to child transmission (vertical transmission)
• Direct exposure to open wound
• Transfusion of HIV infected blood or body fluid

How does a foetus get infected with HIV?

Transmission of HIV to the foetus from an infected mother is called ‘vertical transmission’. It occurs when an infected mother conceive and has direct contact with the foetus through the placenta⁴. The foetus is exposed to HIV directly without any barrier. Pregnancy is an immuno suppressed state due to the high concentration of circulating hormones. Therefore all pregnant women must be screened for HIV infection.

Why do we need to screen for HIV infection among pregnant women?

Ministry of Health Malaysia has started HIV screening among pregnant women in 1997. Objectives of screening are :

• To detect HIV infection in the first trimester in order to start anti-HIV therapy (anti-retroviral therapy)
• To initiate therapy very early in pregnancy and prevent vertical transmission to the foetus
• To minimize HIV complication to the mother by suppressing HIV replication thus reducing obstetric complications
• To minimize intrauterine and perinatal complications to the foetus
• To reduce the risk of miscarriages and intrauterine death
• To minimize exposure of HIV to healthcare providers while caring for the mother during peri-partum period and surgical procedures

The main reason why HIV screening is done in the first trimester is to enable the starting of anti-retroviral therapy as early as 14 weeks period of gestation.

What are the procedures for HIV screening?

Consent from the mother must be obtained before testing. HIV Rapid Test is used to screen for HIV among pregnant women. The test is taken immediately at booking. It is done as early as 10 weeks and latest by 14 weeks period of gestation³. If the HIV Rapid test is positive, next is to proceed with confirmatory HIV test using serological analysis. Positive confirmatory test indicates the mother is infected with HIV. Following positive confirmatory test, anti-retroviral therapy for HIV is to be started as soon as possible. Counselling is given at every step of the procedures². HIV screening is provided at all government health clinics and hospitals. Private medical centres and clinics must also adhere to the government policy of HIV screening.

Possible complications of HIV infection in pregnancy

Maternal complication :

• Opportunistic infection that can lead to severe infection
• Miscarriages
• Haemorrhage
• Severe pneumonia
• Pre-term labour
• Anaemia

Foetal complications :

• Intrauterine death
• Prematurity
• Low birth weight
• Intra uterine growth retardation
• Miscarriages
• HIV infection transmission to the foetus
• Hydrops foetalis

How to prevent HIV infection and transmission?

HIV infection can be prevented by adopting to healthy lifestyle modification, prevent high-risk behaviours example promiscuity and intravenous drug abuse. It can also be prevented by avoiding having sex with HIV infected person or suspicious of HIV infected individuals. Avoid breastfeeding and resort to replacement feeding (infant formulas) is the ideal choice. Use of condoms is so far the best method to prevent HIV transmission through sexual intercourse3. Circumcision has been shown to reduce HIV transmission⁵.

HIV can infect the fetus in the womb

References

1. aidsinfo.unaids.org
2. http://www.mac.org.my/v3/
3. Malaysian Guidelines on Management of HIV in Pregnancy 2008
4. http://www.aids.gov/hiv-aids-basics/just-diagnosed-with-hiv-aids/understand-your-test-results/cd4-count
5. http://en.wikipedia.org/wiki/HIV/AIDS#Acquired_immunodefiency_syndrome
6. who.int/hiv/topics/malecircumcision/en/