Alarm as children and youth develop resistance to ARVs

Kenyan youth and children may be developing resistance to antiretroviral medicines, researchers have warned.

Among infants and young children, the researchers say, under-dosing and resistance to a group of HIV drugs (nevirapine-based regimens) are the leading hindrance to viral load suppression. Bitter medication and lack of appropriate formulations and fixed-dose combinations for children are also making it difficult for children to swallow the antiretrovirals (ARVs).

In adolescents, on the other hand, high viral loads resulted from non-adherence because of stigma, poor transition to adult care, and lack of social support.

For instance, the study results show that about four in every 10 children under three years (43 per cent) and adolescents under 20 years (36 per cent) have high viral loads measuring more than 1,000 copies per millilitre.

This, compared to adults between 30 and 60 years whose viral load was much suppressed such that only one in 10 had a high viral load (13 per cent), is quite high.

HIGH VIRAL LOADS

“Such high viral loads mean that we may not be able to reach the 90:90:90 target set by UNAIDS,” said Dr Matilu Mwau, an infectious diseases specialist.

Chances that a child under three had uncontrolled HIV was nearly five times that in adults.

The audit by the Kenya Medical Research Institute (Kemri) and the National Aids and STI Control Programme (Nascop) appeared in the Journal PLOS One on January 11.

This conclusion was reached following an extensive four-year study that saw an estimated one million people living with HIV assessed to determine whether the antiretroviral drugs they were taking reduced their viral load or not.

According to the first extensive research of its kind by Kenyan scientists, potential under-dosing and resistance to drugs have made it difficult for children living with HIV to have a low viral load.

Viral load is a term used to describe the amount of HIV in a person’s blood. The more HIV viruses there are in one’s blood (and therefore the higher your viral load), the greater the chances of falling ill because of HIV.

If there is too little HIV in your blood that your viral load is ‘undetectable’, then the risk of HIV being passed on during sex is extremely low, even if condoms are not used.

Viral load tests measure the amount of HIV’s genetic material in a blood sample. The results of a viral load test are described as the number of copies of HIV RNA in a millilitre of blood.

Whereas under-dosing occurs when a caregiver does not administer the correct dosage of the ARVs as required, potential resistance can occur either due to failure to adhere to medication or mutation of the virus to make it more hardy hence failure to respond to drugs, the researchers warned.

“Some drugs are administered based on a child’s weight. We know that children vary in weight, therefore, it can be difficult to get a correct dosage at home compared to hospitals,” explained Dr Mwau, who was a lead author in the study.

The study titled “Scale-up of Kenya’s national HIV viral load programme: Findings and lessons learned” is the largest study to be conducted by Kemri and Nascop researchers.

“When HIV drugs are working, patients should be fully suppressed within six months, but it is unclear whether this standard applies to young children.”

To Dr Mwau, the high viral load is a cause for worry because whereas adults are about to reach the UNAIDS target of having viral suppression among 90 per cent of all people receiving antiretroviral therapy by 2020, this may not be the case for the little ones.

“If nothing is done, we may find it difficult to reduce the HIV cases. This means that rates of transmission can increase.”

Viral load testing capacity is still weak in some of the countries with the highest burden of HIV infection in sub-Saharan Africa and needs urgent improvement according to findings from a seven-country study of viral load testing activity published in December last year.

Each year worldwide, an estimated 1.5 million women living with HIV give birth.

Nationally, there are 897,644 Kenyans on ARVs — 71,547 are children between under 14, while 826,097 are adults aged 15 and above.

Additionally, there are more than 1,000 HIV treatment sites in Kenya where a patient’s viral load is tested annually.

“At the beginning of treatment, patients are usually advised to check their viral loads every six months. If the drugs are working as they should, we advise them to test once every year,” continues Dr Mwau.

The World Health Organisation recommends that everyone taking antiretroviral treatment should receive a viral load test six months after starting treatment and every 12 months thereafter to check that viral suppression has been achieved and maintained.

Achieving a high level of viral suppression among people on antiretroviral treatment is also important for achieving the third 90:90:90 goal – 90 per cent of people on ART virally suppressed by 2020.

REDUCTION OF HIV TRANSMISSION

Achieving this goal is projected to reduce HIV transmission as well as ensure the maximum health benefit from ART.

Some people, however, are not aware of their viral loads because they are not going for these tests. Further, experts think that about 400,000 people suspected to be HIV positive are not on treatment, hence adding to the risk.

It is estimated that Kenya has 1.6 million people living with HIV. Of these, 1.2 million have been tested and found to be having the virus and most are already on treatment.

Breaking down the numbers even further, Dr Mwau says that only 1.1 million people know their viral load and out of these, 176,000 (or 16 per cent), majority being young people, have high viral loads. This means that they pose a risk of infecting others.

The first case of HIV in Kenya was detected in 1984 and, by the mid-1990s, it was one of the major causes of mortality in the country, putting huge demands on the healthcare system as well as the economy.

Prevalence of the virus peaked at 11 per cent in 1996, and has fallen to six per cent by 2015, mainly due to the rapid scaling up of HIV treatment and care.