The First South African National TB Prevalence Survey gives a clearer picture of the epidemic
Cape Town | While South Africa (SA) remains severely affected by the COVID-19 pandemic, it continues to suffer from four other colliding epidemics, namely tuberculosis and HIV/AIDS, maternal, newborn and child deaths; non-communicable disease and violence and injury.
Regarding TB, the country is among the top 30 countries most burdened by tuberculosis (TB). These countries contribute 87% of the estimated incident TB cases worldwide. South Africa is also among 14 countries with the highest burden of multi-drug resistant TB (MDR-TB) and TB and HIV comorbidity.
These were some of the findings presented at the recent launch of the First National Tuberculosis Prevalence Survey South Africa 2018. The Minister of Health, Dr. Zweli Mkhize presided over the launch via a webinar, and was joined by officials from the Department of Health and a team of experts that were involved in conducting the survey.
The Survey, the first of its kind for South Africa, was undertaken by the Tuberculosis Platform of the South African Medical Research Council (SAMRC) in collaboration with the Human Sciences Research Council (HSRC) and the National Institute for Communicable Diseases (NICD). The survey was done according to the World Health Organization recommendations for conducting national TB prevalence surveys, sought to test for tuberculosis in 55 000 individuals, older than 15 years, in 110 small area layers across all nine provinces of the country using multistage cluster sampling techniques.
Only 39 191 subjects participated in the survey and among these, the overall prevalence of bacteriologically confirmed pulmonary TB for 2018 was estimated to be 852 per 100,000 individuals, measured with a high certainty that the true adult TB prevalence would be in the range 679 - 1 026. Sub-group analyses revealed that males (1094; 835 – 1352) had a higher prevalence than females (675; 494 – 855). Thus, the disease was more prevalent in men than in women by 1.6%. Worryingly, the TB prevalence was highest in the age groups 35-44, the economic active part of the population, and the over 65 years. The survey found lowest participation among the youth and males – pointing to the need for rigorous awareness and innovative ways to reach these population groups.
A critical finding was that more than two-thirds of HIV negative symptomatic participants had not sought care for their symptoms and that a higher proportion of HIV negative people were asymptomatic than those who are HIV positive. This, the Minister said “will require a shift in the way we achieve proactive health-seeking behaviour. Previously, we focused on symptomatic patients and those living with HIV. We now need to encourage everyone to screen and test for TB to achieve elimination."
The prevalence estimate can be used to calculate the total number of people who had TB disease in 2018, being 390 000, but only 235 652 notified, showing that 154 348 people had TB in the country but not known by the National TB Control Programme.
Prof Martie Van der Walt, Co-Principal Investigator of The Survey and Director of the Tuberculosis Platform at the SAMRC said the findings of this survey are a landmark event in the epidemiology of TB in South Africa.
“Going forward, the results will provide the much-needed evidence to influence response strategies, programmes and interventions to reduce morbidity and mortality of TB in the country”, she said. She added that the country would need a follow up survey in 5-years’ time to be able to measure how successful the National Department of Health was in implementing the findings of this 2018 survey.
“A tuberculosis prevalence survey is a massive undertaking; it takes five or more years from planning up to the results being available and requires massive resources. We now have a fairly accurate picture of how the situation in SA was in 2018, and if we correctly implement the survey findings, we should be able to measure successes in five years’ time”, emphasized Prof Van der Walt.
A sentiment shared by the Co-PI of the survey, Dr Sizulu Moyo of the HSRC was that knowledge and awareness of the symptoms of TB are poor and there was delay in health-seeking of individuals with TB and a high burden of undiagnosed disease in communities. The TB burden causes an enormous health challenge to the people of South Africa and an understanding of the true burden and the reasons for poor health seeking is critical to devise strategies to find and treat all individuals with tuberculosis.
Director of the SAMRC’s Office of AIDS and TB Research and the co-chair of the National TB Think Tank, Dr Fareed Abdullah, emphasized that the survey was “the first time ever that we have a direct measure of the prevalence of TB in South Africa which will improve our ability to plan properly to address the TB burden and to measure whether the situation is improving or getting worse. The large proportion of asymptomatic TB that was observed in the survey implies that we need new tools for screening TB, a higher index of suspicion and new diagnostic tools.”
SAMRC President and CEO, Prof Glenda Gray welcomed the release of the findings and described it as one of the most important steps for the management of TB in South Africa. “The decision by the SAMRC to use digital chest X-rays to diagnose TB in the survey has shown that digital X-rays supported by automated reading should be used more widely in the detection of TB, especially for asymptomatic TB in the communities,’’ said Gray.
NOTE TO THE EDITOR:
More about the First National Tuberculosis Prevalence Survey
The Survey was commissioned by the Department of Health in 2015 to get an understanding of the burden of TB in the general population aged 15 years or older in the country. The main aim was to determine the bacteriological confirmed prevalence of TB in South Africa across all nine provinces, having commenced in KwaZulu-Natal in August 2017 and concluded in Western Cape Province in 2019.