Saturday, 25 April was World Malaria Day. This year’s theme was ‘Invest in the future, defeat malaria’. The University of Pretoria’s Centre for Sustainable Malaria Control (UP CSMC) believes that research is critical in combating malaria in a manner that is sustainable and without the potentially adverse health effects of toxic chemicals.
One of the ways in which the Centre interpreted this year’s theme, is that we should invest in our up-and-coming malaria researchers who develop new and innovative intervention methods to defeat this disease. As part of the Centre’s World Malaria Day activities, a group of 18 postgraduate students of the UP CSMC, who are working on malaria-related projects, travelled to rural Tonga in Mpumalanga Province, South Africa, to visit the Tonga Malaria Training Station, where they could get a more practical view of how the disease is fought on ground level.
Mr Aaron Mabuza, Malaria Control Programme Manager for Mpumalanga, spoke to the students about the work that he and his team are doing. He explained that one of the key programmes that the Tonga Malaria Training Station is involved with is the training and consequent management of insecticide spray workers who play a major role in Mpumalanga’s and South Africa’s control of the malaria vector (mosquito) itself.
Because malaria vectors are considered endophilic, meaning that the mosquito vectors rest inside houses after taking a blood meal, it is possible to control the prevalence of the insects that carry the disease through indoor residual spraying (IRS). As the name implies, IRS involves applying a residual insecticide to the walls and other surfaces of a house. The insecticide will then kill mosquitoes and other insects that come into contact with these surfaces for several months. It is important to note that the process does not necessarily prevent people from being bitten by mosquitoes, but rather kills the insects when they come to rest on the surface after they have fed, thus preventing transmission of infection to other persons.
The Tonga Station is equipped with training facilities and accommodation for the spray workers undergoing training. Training usually takes place in August so that enough sprayers are available to cover the target area, because to be effective, IRS has to be applied to a very high proportion of households in an area – usually more than 80%. For the 2014/2015 malaria season, 321 temporary spray operators were trained and employed. In addition to the training of spray workers, the Station also runs yearly awareness and education campaigns to educate affected communities about malaria control and prevention strategies.
South Africa is one of the few countries in the world where dichlorodiphenyltrichloroethane, better known by the acronym DDT, is still used for vector control. Although use of this chemical is contentious, the responsible application thereof has been successful in reducing malaria transmission and related deaths in the three malaria-endemic provinces – Limpopo, Mpumalanga and KwaZulu-Natal. As the benefits in using chemicals for the control of malaria outweigh the human and environmental risks associated with these chemicals, there is agreement that public health efforts are needed to reduce reliance on chemicals. In an effort to find sustainable ways toward eliminating malaria, researchers at the UP CSMC are currently involved with various projects inter alia to determine the effects that chemicals used for insect control have on people living in the affected communities and also to find safer alternatives for vector control. Recently both Prof Tiaan de Jager (Director of the UP CSMC) and Prof Riana Bornman delivered plenary lectures on the topic at an international congress in Copenhagen. The UP CSMC’s work on insecticide exposure and health effects is internationally recognised.
According to Mr Mabuza there was an increase in the total number of malaria cases reported during the past season. He says that 75% of reported cases were however imported from other malaria areas and countries outside Mpumalanga, meaning that only 25% of cases contracted the disease locally in Mpumalanga. The case fatality rate was only slightly above the national and provincial norm of 0,5%. This relatively low mortality rate, he says, can be attributed to successful vector control through the spraying of houses, which is done between September and December each year. Another contributing factor to the low mortality rate in the province is the high rate of early diagnosis and treatment of malaria cases achieved by health workers in the province. Most diagnoses are still made using antigen-based malaria rapid diagnostic tests (RDTs) when a patient presents with symptoms at a clinic, but it is the second, more proactive testing approach employed by the programme that allows health workers to identify the majority of cases before they become too serious.
When a patient is diagnosed with malaria, health workers take blood smear samples from the patient’s immediate family members and close neighbours to determine if they were infected by the same parasite carrying mosquito. At present the blood smears are sent to the National Institute for Communicable Diseases (NICD) in Johannesburg for analysis, but the Station plans to analyse all samples locally once their own laboratory becomes operational.
Apart from the laboratory that will be available to staff at the Tonga Malaria Training Station in the future, the Station has also taken the first steps towards establishing a state-of-the-art insectary, which will allow researchers at the Station to study the behaviour of the mosquitoes that carry the deadly malaria parasite, thereby enabling them to develop more effective methods of vector control. The Station may also serve as a future field station for UP CSMC staff and students. The UP CSMC already has a satellite research facility in Vhembe District in Limpopo Province and Dr Sunday Ukpe from the UP CSMC is actively involved in promoting early diagnosis and the effective treatment of malaria in Mpumalanga.
The dedicated staff at the Tonga Malaria Training Station has been an inspiration to all the students who have had the opportunity to experience the practical side of the fight against a disease that they normally only get to study in a laboratory. All indications are that the team at the Station have made strides towards eliminating the disease in South Africa. According to Mr Mabuza, the largest remaining challenge is for them to find a way to effectively control the spread of the disease from neighbouring countries, where effective control strategies are largely lacking. He says that he firmly believes that it will be possible to eliminate the disease in South Africa by 2018, provided that countries where the disease is endemic work together towards achieving this goal. According to Prof de Jager, the UP CSMC is doing innovative and leading research to support the country and the African continent in efforts to eliminate malaria.