TB prevention programmes need to catch up with the strides made in worldwide HIV prevention

Before Covid-19 came along, the two most lethal infectious diseases were HIV and tuberculosis (TB). Even though HIV still lingers, with 1.5 million people contracting the infection every year, epidemiologists point to the availability of many HIV prevention options as a primary reason for the decreasing caseload.

According to the World Health Organization (WHO), over the past two decades, new HIV infections decreased by 49%, HIV-related deaths decreased by 61% and an estimated 18.6 million lives were saved because of new treatments that minimise the infection and prevent its spread.

We have so many options for HIV prevention at our disposal, including the dapivirine vaginal ring, oral Pre-Exposure Prophylaxis (PrEP), harm reduction for people who use drugs, condoms for both men and women, voluntary medical male circumcision and the recently approved long-acting cabotegravir, with even more options in development. 

We have a suite of prevention tools because everyone is different, and people need to be able to choose their methods according to the way they live their lives. We observe a similar abundance of choice within family planning with oral pills, a variety of injectables, intra-uterine devices and condoms — we share this prevention method with HIV programmes.

We do not have this many options for TB prevention, but the world needs to adapt to embrace choice if we are to meet the globally agreed-upon goal of reducing TB deaths by 90% by 2030 — referred to as the “End TB Targets”.

The urgency of the need is clear: an estimated 1.6 million people lost their lives to the disease in 2021 — the second consecutive year the death toll went up after 14 years of progress. 

In Africa, an estimated 2.5 million people contracted the disease in 2021 — one million of whom were never diagnosed and treated. 

Yet, there are glimmers of good news. 

Despite the Covid pandemic, estimates of TB incidence have slowly declined over the past few years in Angola, Ethiopia, Gabon, the Republic of Congo, Sierra Leone, South Africa, Tanzania and Zambia — all countries with high burdens of TB. 

Of these, Zambia has also had success in finding and diagnosing an increasing number of these infections; the pandemic impacted the surveillance efforts of the other countries. 

As for HIV, there is no effective vaccine to prevent TB in adults: the BCG vaccine only prevents severe TB in children. 

However, there are ways to prevent TB when someone is potentially exposed to an infected person. In the workplace or when a family member at home becomes sick, for example, prevention starts with masking, which was traditionally used in clinical care settings.

The other ways work through prophylactic regimens. For TB, we initially only had isoniazid that could be taken for six, nine, 12 or 36 months, depending on country guidelines, but now we have shorter regimens that allow for patient choice.

These options include regimens lasting one (1HP) and three months (3HP), with different combinations of the antibiotic drugs rifapentine and isoniazid, all with vitamin B6 supplements to help counter some of the side effects of treatment. There is also a three-month regimen of rifampicin and isoniazid (often given to children and adolescents) and a four-month regimen of rifampicin alone.

Longer courses of isoniazid taken for six to 36 months also remain options, though most people are eligible to take a shorter rifapentine-based or rifampicin-based regimen and should be given the choice to do so.

Greater access needed