The whirlybird has no pretentions, doesn’t discriminate and simply and humbly performs the task for which it was designed. It is an elegant design solution. It effectively circulates the air in a room. Recently its efficiency has been underscored. Recently this humble piece of design has proved itself to be a potential lifesaver.
The South African TB epidemic and the South African HIV epidemic individually are both among the world’s worst ‘ making South Africa’s dual epidemic of HIV and TB a potent combination of public health epidemics that cause illness and death, economic hardship and societal challenges. To use popular parlance: South Africa’s dual epidemic of TB and HIV is a perfect storm.
The South African TB incidence rate (558 per 100,000), one of the highest incidence rates in the world, has increased dramatically as the HIV epidemic has worsened, with the number of TB cases more than doubling since 1996. The increased prevalence rate of TB, not surprisingly, has been directly related to the HIV incidence rate.
In Khayelitsha for instance, the antenatal prevalence of HIV is 30% and the TB case incidence rate is above 1200 per 100,000, both above the national average. Approximately 400 MDR-TB cases are estimated to emerge each year in Khayelitsha. Tuberculosis that is resistant to practically every medication that can be used to treat it, multi-drug resistant TB (MDR-TB) or extensively-drug resistant TB (XDR-TB), is alarmingly common in South Africa.
It is estimated that at least 50% of TB disease in people living with HIV in South Africa can be attributed to transmission within clinics. This estimate is tragic and sadly ironic. As services and treatment for HIV positive people became/become available the spaces in which these services are rendered also became the spaces in which TB is contracted. Clearly, these hard-won services and life-saving interventions cannot be done away with.
Consequently, in order to successfully address the dual epidemic faced in South Africa TB infection control needs to be improved in all clinics across the country, both rural and urban.
Enter the Whirlybird.
Once again MÃ©decins Sans FrontiÃ¨res has been at the forefront of addressing South Africa’s epidemics and this time they have enlisted design. MSF, or Doctors Without Borders, identified the urgent need to develop an evidence-based, low-cost and practical intervention to reduce the risk of TB transmission in health care facilities. The existing alternatives; mechanical ventilation, ultraviolet germicidal irradiation (UVGI) etc., are ill suited to the needs of developing countries because of their expense in installation and maintenance. Accordingly, MSF focused on natural ventilation as an appropriate alternative for resource poor and rural health care settings.
They realised wind-driven roof turbines are a potential low-cost, low-maintenance technology, which also does not require electricity. Research was undertaken to ascertain to what extent these wind turbines could assist in improving airflow and ventilation, and therefore contribute to the effective infection control of TB, including drug-resistant TB.
The Center for Disease Control’s infection control guidelines stipulate the need for 12 air changes per hour (ACH) although a minimum ACH of 6 is acceptable in order to facilitate infection control. MSF’s research in Khayelitsha found that even with a wind-speed of less than 10 km/h an average of 9 ACH was achieved using the Whirlybird alongside a door or window grate. On average, according to MSF’s measurements, the wind-speed in Khayelitsha is 10.6 km/h meaning that on average the ACH was around 12.2.
With the Whirlybird acceptable ACH levels are reached even with low wind-speeds, patients and staff feel less draughts and unlike windows, patients or staff can’t shut the Whirlybird meaning ventilation stays constant.
Clearly the Whirlybird has the potential to help address and mitigate South Africa’s perfect storm. However, the Whirlybird’s remarkable potential, its merits as a design intervention, are dependent on resource allocation and on political will. Thankfully, MSF is on it. Why thankfully? Because MSF has been here before. MSF identifies life-saving interventions, backs it up with research and evidence and then campaigns alongside its civil society partners to have these life-saving interventions adopted nationally, regionally, across the continent and then globally.
Ultimately, we clearly need the life-saving potential of the Whirlybird, but interestingly it also needs us.
So let it sound: Phambili Whirlybird, phambili.
* Dalli Weyers is a social justice activist and author of the blog Reclaim Fire