Cholera remains a significant threat to public health, especially to vulnerable communities with no access to
safe drinking water and proper sanitation.
Cholera is not considered to be endemic to South Africa and does not occur regularly. In such instances, an outbreak is defined by the occurrence of at least 1 confirmed case of cholera with evidence of local transmission. For the Hammanskraal area, the recent outbreak was triggered by the case of a traveller from Limpopo, confirmed on 15 and 18 May 2023. Soon after, the National, Provincial and District Outbreak response Teams were activated to conduct field investigations on the source of contamination, case finding and contact tracing, as well as health promotion activities to curb the spread of the disease in the area. On 31 May 2023, the Water Research Commission (WRC) was mandated by the Department of Water and Sanitation to undertake an independent analysis of the cholera outbreak in Hammanskraal, focusing on the role of water, sanitation and hygiene in the spread of the disease.
This study was aimed at answering the following questions:
• At the time of the study, could toxigenic Vibrio cholerae (the causative agent of cholera in humans) be detected in any water sources including freshwater water bodies such as rivers and dams, wastewater and/or drinking water in the Hammanskraal area? And if so, what are the implications for disease transmission linked to various water uses within the area?
• What is the functional status of the wastewater and drinking water treatment plants within the Hammanskraal area and are they adequate in serving as barriers to waterborne disease transmission to communities?
• Were the climatic conditions around the outbreak period favourable for the occurrence, survival and transmission of the toxigenic Vibrio cholerae in the water environment?
• What is the status of the provision of safe water, sanitation, hygiene and solid waste collection services in
the area and its likely contribution to the spread of cholera within the designated area?
• What is the general level of public awareness on the importance of water, sanitation, hygiene and health
(WASH) practices and their role in the spread of oral, faecal-oral (person to person) diseases?
To achieve this, several studies were commissioned in collaboration with WRC experts, national science bodies
and consultants. Below is the summary of the main findings:
1. Water as the source of contamination and medium for cholera transmission
• Sampling was undertaken approximately three weeks after the first case of cholera was confirmed. With
regards to human health risks exposures through domestic water use, the identified primary sources of water for use by residents in Hammanskraal include municipal water supplied from the Klipdrift Water Treatment Works, the Temba Water Treatment Works, tankers obtaining water from Rand Water, fire
hydrants, etc, household boreholes and hand-dug wells mostly concentrated in the Stinkwater area as well as the commercially available bottled water. Water samples collected from selected sources used for domestic purposes, did not show any presence of the toxigenic cholera strain.
• Analysis of water samples collected from various points in natural bodies within the designated area revealed a very high degree of fecal contamination. This was confirmed by the presence of excessive numbers of E. coli and the presence of other known enteric pathogens such as Salmonella and Shigella.
Therefore, the very poor microbiological quality of the river indicates that it is not acceptable for recreational use including religious rituals baptisms, swimming and bathing.
• Only one of the samples collected along the Apies River, downstream from the Temba Wastewater Treatment Works tested positive for the presence of the toxigenic Vibrio cholerae strain. This observed presence downstream could be attributed to the general circulation of the strain in the community.
• The impact of using river water for irrigation was investigated by collecting a total of 140 water, fresh produce, and sediment samples in different farms within the Hammanskraal area and analysed for the presence of the toxigenic Vibrio cholerae strain. The toxigenic Vibrio cholerae strain was detected in water samples collected from the Kaalplaasspruit, which flows into the Apies River further downstream
in the Hammanskraal area.
• Although this study was unable to pinpoint the source of the Hammanskraal cholera outbreak, it
highlighted some important public health risks which may well contribute towards causing future cholera and/or other waterborne disease outbreaks.
2. Assessment of the functionality of the Rooiwal Wastewater and Temba Water Treatment Works
• To assess the adequacy of the water/wastewater treatment plants in the area in serving as barriers to
disease transmission, technical functionality of both the Rooiwal Wastewater Treatment Works and
Temba (drinking) Water Treatment Works was assessed. Although toxigenic Vibrio cholerae was not detected within either plant, results from the assessment showed that both plants are dysfunctional.
Both the final treated wastewater and final treated drinking water was found not to be compliant with the regulated water quality standards, highlighting the community’s susceptibility to health risks.
3. Climatic and environmental water conditions during the outbreak period
• During the outbreak period, both the rainfall patterns and temperature were suitable for the occurrence and transmission of the toxigenic Vibrio cholerae in the environment. Additionally, excessive pollution levels were observed in both the Pienaars and the Apies Rivers systems, manifested by the dominant
visual presence of blue-green algae and water hyacinth. This presents potential water use related health risks.
4. Status of water, sanitation, and hygiene services/practices and risks for cholera transmission.
• The Hammanskraal area is served using municipal sources and other means of self-supply such as boreholes and hand-dug wells. The sanitation facilities that were identified include flush toilets, septic tanks, chemical toilets and pit latrines. It was noted with great concern that in some areas there was no running water to flush the shared toilet facilities due to the prevalence of intermittent water supply, pushing the affected residents to riskier alternatives. In the RDP sections of the settlement, most of the wash basins that were previously installed outside the toilets are dysfunctional and have regrettably
detached from the walls. The absence of running water, hygiene facilities and soap within the toilet area implies that most individuals in the affected areas seldom wash their hands with soap after using the toilet, leaving the community vulnerable to the risk of any faecal pathogen transmission.
• Illegal solid waste dump sites within the Hammanskraal area present a threat to water bodies in the area and presents a source of faecal contamination that can perpetuate disease transmission.
Recommendations
It is especially important to recognise the uniqueness of the cholera outbreak so that the response strategy is adapted to the specific context, and is timeous, comprehensive and well-coordinated. Based on the findings from this investigation, the following is recommended:
• Integrating water and wastewater quality surveillance into early warning systems for cholera outbreaks and considering the impacts of climate change – Water and wastewater quality surveillance is critical for early warning and preparedness in the context of disease outbreaks, particularly
considering the potential influence of the current climate variabilities on disease transmission.
Regularly monitoring the quality of water sources, including surface water bodies, groundwater, drinking water and wastewater for indicators of faecal pollution (e.g., E. coli) is important as it assists in detecting the presence of potential human pathogens, such as the bacteria causing cholera. This aspect calls for a need to strengthen the implementation of the Department of Water and Sanitation’s established National Water Monitoring programmes.
• Outbreak response – At the onset of an outbreak (one case confirmed), early detection, surveillance, treatment and case management are critical in managing the spread of cholera. During cholera outbreaks, accredited laboratories play a critical role in confirming diagnoses and identifying the causative strain for tailoring treatment and implementing targeted control measures. For water quality
surveillance, only two laboratories in the whole country were operational, which hampered the timely surveillance and reporting of information. If not addressed, the situation can delay the implementation of public health responses to contain the outbreak.
Community involvement in the planning and implementation of outbreak response efforts is vital. Engaging with the community ensures that
community knowledge/practice gaps on curbing cholera spread are addressed, and that government led interventions are culturally sensitive, acceptable, and well-received.
• Improving access to clean drinking water and sanitation facilities, promotion of safe household water treatment, storage and handling, as well as safe hygiene practices are vitally important in
preventing the spread of cholera and other waterborne diseases – Generally, the poor water services situation in Hammanskraal poses a high risk to public health. Most importantly, the Rooiwal Wastewater Treatment Plant must be upgraded to increase capacity. Design capacity for the nutrient removal plant is around 3 x 40Ml/d, but flow rates could be up to 200Ml/d. Parts of the plant must be overhauled too, because it is dysfunctional. A fresh and detailed look at the plant is needed, to see
how to get it to what could be considered best practice. A simple upgrade will not solve existing design
flaws and perpetuate them into the future.
• Water (re)use quality and safety – According to international standards, the use of water source that contains wastewater, whether unplanned/incidental or planned, is classified as water reuse. The
unplanned water reuse situation in the case of Hammanskraal presents inherent human health risks
due to the poor wastewater from both the Rooiwal and Temba Wastewater Treatment Works, and contaminated surface run-off from land, which enters natural water bodies, which are in turn used by the community for cultural, religious, recreational purposes, irrigation, and for production of drinking
water. It is imperative that best practices and standards for water reuse quality and safety for various uses (cultural, religious, recreational, irrigation, drinking, etc) are followed to safeguard public health.
This implies that the process configurations for the wastewater and drinking water treatment plants
should include advanced treatment technologies to ensure removal of all contaminants of concern (known and emerging) in the incoming water.
Lessons from the Hammanskraal outbreak can help build resilience for the future.
The WRC has established a
panel of advisors and subject matter experts who will continually provide valuable insights and support on
setting up key indicators that can serve as early warning signs for future waterborne diseases, advise on the
establishment of a communication network to disseminate early warnings and preventive measures to
communities, and strengthen current contingency plans and protocols for responding to waterborne disease
outbreaks.