Table 2 List of interventions included in the mathematical model

Passive Case Detection

Uncomplicated malaria treated with Artemether lumefantrine through public health facilityes and the private sector based on treatment seeking data and KAP studies

Severe malaria treated in hospital with IV Quinine and IV artesunate determined by data

Indoor Residual Spraying

Modelled by insecticide type (DDT, non-DDT) as coverage determined by the number of structures sprayed (data informed) and the population at risk in need of spraying. In consultation with the technical task team entomologists and vector surveillance teams, the waning in effectiveness of the sprays was modelled in line with the WHOPES recommendations. The main vector responsible for malaria transmission in South Africa (Anopheles arabiensis) is known for its outdoor biting and resting behavior. By accounting for probabilities of indoor biting, indoor resting, repelling and killing effectiveness, effectiveness (for a newly sprayed structure) is computed at 38%. This effectiveness will decrease with the cumulative IRS coverage over time. These numbers have been sourced from existing literature and verified/adjusted by the Technical task team

The success of IRS with DDT is well documented in South Africa with a decrease in incidence of 91% experienced following the reintroduction of DDT (combined with introduction of ACTs) after the 2000 epidemic {Hargreaves, 2000 #23; Maharaj, 2005 #24; Sharp, 2007 #22}

DDT has been successfully used in South Africa for decades and was the primary reason for the significant decline in cases during the 1996–2000 epidemic. DDT was used to reduce the population of Pyrethroid-resistant Anopheles funestus vectors and is still being used to drive back the spread of these mosquitoes that are prevalent in neighboring countries

Active Case Detection

Modelled for districts within Mpumalanga and KwaZulu-Natal. Not active in Limpopo currently, but included as incidence is projected to decrease by 2022 due to all risk spraying activities under the Accelerate and Source Reduction scenarios

Proactive Case Detection

Modelled for districts within Mpumalanga and KwaZuluNatal. Not active in Limpopo currently as incidence is too high. Malaria Surveillance Agents (MSAs) take 3 slides per day and follow up positive cases to receive treatment in KwaZulu-Natal. Also includes screening and testing in areas which may have high numbers of asymptomatic carriers such as seasonal farming areas and mining communities

Border Surveillance

Border units are operational in certain districts within Limpopo, Mpumalanga and KwaZulu-Natal (South African side only) and their detection of positive cases is modelled in line with the data received from the physical units