Letter from South Africa

Abstract

South Africa has many struggles. Respiratory health is one of them. The main challenge faced by South African clinicians and researchers is to address respiratory health in the face of gross inequality (Gini index 0.63). This disparity is seen within the health sector where care ranges from limited primary healthcare to worldclass care with cutting edge technology and expertise. Similar to other countries with a large population living in poverty, South Africa has a disproportionate amount of respiratory disease with the majority of disease occurring in the poorest communities. Early life factors drive the epidemic as children born into poverty are exposed to multiple factors that disrupt lung health and alter the trajectory of lung development.1 While antenatal factors, premature birth, environmental pollutants and biofuel and tobacco smoke exposure are likely as disruptive to lung health as in developed countries they are overshadowed by infectious lung disease. Pneumonia remains a leading cause of childhood mortality while HIV and pulmonary tuberculosis (PTB) further contribute to acute and chronic respiratory disease. Despite its many challenges, South Africa has recognized the importance of child health and implemented policies to protect children's wellbeing. The right for children to access free healthcare is enshrined in the South African Constitution and it is illegal to smoke in public spaces. Programs are in place to provide childhood vaccinations though viral vaccinations, specifically respiratory syncytial virus, are lacking. Additionally, programs to limit the vertical transmission of HIV, provide antiretroviral therapy (ART) and treat tuberculosis are in place. While the HIV and Tuberculosis programs are well established and have made progress in limiting disease, there are signs that these programs may be faltering. A recent WHO report demonstrated an increase in TB incidence in South Africa. Concerningly, in our clinical practice we are seeing an increasing number of children with HIV infection. In these children, HIV diagnosis and ART initiation is often delayed increasing the risk of pneumonia and tuberculosis. Furthermore, delayed HIV diagnosis and ART initiation is associated with structural lung disease. Children with HIV infection have diminished lung function throughout childhood which does not recover if ART is initiated late in childhood. Encouragingly there is evidence that following early HIV diagnosis and ART initiation lung function follows a similar trajectory to HIV-unexposed children until adolescence.2 It remains unknown whether these individuals will have altered adult lung health. After the early success of the HIV programs renewed vigilance and action is required to limit HIV transmission, initiate ART early and mitigate the lifelong effect of HIV infection on lung health. Tuberculosis incidence remains high and reflects the on-going poverty of South Africa. In the words of the late Donald Enarson 'track poverty and you track TB'. The respiratory sequelae of PTB lasts well beyond the infection with the disease burden being greatest in those who have tuberculosis earlier in life.3 Following completion of treatment, airflow limitation persists in adolescents and supranormal decline of FEV1 increases the risk of early-onset chronic obstructive pulmonary disease (COPD). A combination of accurate point-of-care diagnostics and effective therapy is required to limit the long-term respiratory consequences of PTB. The accurate diagnosis of PTB in children is difficult. New molecular technologies (XPERT/XPERT-ULTRA) promised point-of-care testing, same-day results and rapid treatment initiation. However, in our experience, polymerase chain reaction (PCR)-based PTB diagnostics have not delivered on this promise. PCR-based testing is still performed in central laboratories and even in-hospital diagnosis can be delayed. The lack of rapid, reliable microbiological and molecular PTB diagnostics has resulted in the chest radiograph (CXR) being increasingly used in the diagnosis paediatric tuberculosis. While supported by the WHO and local diagnostic algorithms, CXR diagnosis of PTB can lead to overdiagnosis. This is especially prevalent in South Africa, where CXR abnormalities have become synonymous with PTB without due consideration of an alternative diagnosis. We encourage clinicians to remain vigilant to use CXR to diagnose PTB in children without additional supporting evidence. Despite the socioeconomic adversity, there is concerted focus in South Africa to improve anti-tuberculous treatment and prophylaxis. Trials performed in South Africa have identified strategies to diminish the duration of therapy in children with non-severe PTB and remove injectables from multi-drug resistant TB regiments. While these strategies contribute evidence to best practice and are of great value to individuals they do not address the core underlying problem driving the TB epidemic-ongoing poverty. An eye-opening study in India demonstrated that providing nutritional support to household TB contacts diminished TB infection and disease in the household.4 It is tempting to hypothesize that focusing on alleviating poverty rather than on drug therapy may be the solution to the South African TB pandemic. Complicating the understanding of chronic respiratory disease in South Africa is the limited longitudinal data of lung health and lung function. Available data of childhood lung function trajectories demonstrate that even control populations have sub-normal lung function.2 Without population specific norms it is unclear whether this represents population level lung disease or inappropriate reference data. Given South Africa's diverse population, varying environmental and socioeconomic climates, range of infective disease and disparate income it is difficult to know what normal lung function and respiratory health is. Current studies are largely performed in poorer communities and to our knowledge none have compared the lung health of poor to wealthy South Africans. Table Mountain, Cape Town, South Africa. None declared.