Most South Africans are not worried about malaria, although the disease is endemic in the country. Four of the country’s nine provinces are at risk for malaria, while 10 percent of the population is at risk of contracting malaria.
The lack of concern may be due to the fact that the country has a relatively low burden of disease. In 2020, South Africa had 8,126 cases and 38 deaths. This is low compared to the estimated 10,007,802 cases and 23,766 deaths in Mozambique during the same period.
The small number of cases means that South Africa is a candidate to eliminate malaria. To achieve this goal, the country will have to not register new infections for three years. This goal was recently achieved by China and El Salvador in 2021 and Argentina and Algeria in 2019.
The region in South Africa that is most likely to achieve this status is KwaZulu-Natal, where the incidence rate is very low. But there are threats to achieving the goal.
In a recent paper, we outlined our findings on malaria in northern KwaZulu-Natal. We found that some species of malaria-carrying mosquitoes show resistance to insecticides. Although resistance levels are low, they still point to a potentially worrying trend.
This is not the first time insecticide resistance has been reported in the province. Tracking resistance is important because it gives an early warning sign of impending danger. The loss of insecticide efficacy can be a major blow to malaria control efforts.
Malaria incidence rates can change very quickly. This was the case during the 1996-2000 epidemic, which was caused by a combination of insecticide resistance and antimalarial drug resistance.
Insecticide resistance is a growing threat to malaria control efforts worldwide. In South Africa, residual indoor spraying is the cornerstone of malaria elimination efforts. That is why it is important to closely monitor mosquito populations in the affected areas.
Coordinated efforts by the government ensure that malaria infection rates are reduced again. Our research shows that there must be extra vigilance to ensure that there is no other jump.
Resistance
Our study was conducted as part of the ongoing monitoring of malaria in the country. Malaria surveillance is essential for provincial control and eradication programs. These surveillance activities include collecting mosquitoes, identifying them and testing their susceptibility to insecticides. The aim is to provide important information on vector mosquito populations in the affected areas, such as their feeding, breeding and resting behavior and their susceptibility to insecticides.
In our article, we looked at Anopheles with a special focus on Anopheles arabiensis, which is the main vector of malaria in the northern part of KwaZulu-Natal.
We collected specimens of Anopheles from Mamfene, Josini, northern KwaZulu-Natal between November 2019 and April 2021. We conducted standard insecticide susceptibility tests. They show resistance to DDT, permethrin, deltamethrin and bendiocarb, as well as complete sensitivity to pirimiphos-methyl. These are classes of insecticides that are approved for indoor spraying.
The levels of resistance we found are still low, with an average survival rate of 12%. But they are still worrying.
If insecticide resistance becomes widespread, this can lead to job failure. This would mean that current mosquito control strategies based on insecticides will not be effective. This in turn can lead to an increase in the number of mosquitoes with an increase in the density of parasites.
It is therefore essential that control is maintained and strengthened by adopting appropriate strategies to prevent the development of insecticide resistance.
South Africa is aware of the problem and has adopted malaria control programs that use at least two different insecticides in mosaic sprays. This approach has proven to be extremely successful. This is like using a multi-drug approach to fight resistance to bacteria and viruses. This will slow down the development of insecticide resistance compared to the use of a single insecticide.
There is no time for complacency
The low number of cases in South Africa means that the country is a candidate for the elimination of malaria. But this is not the time for complacency. The surge in malaria cases in South Africa in 2017 shows how quickly progress can be reversed.
Different countries have left malaria in history. China is the last country to achieve this, which is significant due to its population size and geographical area.
South Africa could join the list, with the province of KwaZulu-Natal at the forefront of the elimination charge. Still, the province is a reminder of what could happen if the country abandons its vigilance.
Malaria is a dynamic disease and mosquitoes do not respect boundaries. The epidemics of 1996-2000 and the jump in cases in 2017 must be a stern warning of what might happen, especially if complacency intervenes.
(Conversation)
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