Vector control through Indoor Residual Spraying (IRS) was introduced in Zone 1 in Mozambique with Bendiocarb at 400mg per m2 in November 2000. The malaria vector control component in Mozambique has been implemented in phases starting with Zone 1, in 2000, which is the area extending from the KwaZulu-Natal border to Maputo (See map) . Zone 1A is the area surrounding the MOZAL Plant which introduced malaria control as part of their social responsibility campaign, implemented in 2001. Phase three, initiated in 2002, focussed on Zone 2A, comprising part of the Boane District, and Zones 2 and 3 extending north along the Kruger National Park border, covering an area of over 20 0002 Km. The contiguous malaria control area in the region now exceeds 100 0002 Km.
IRS started in Swaziland in the 1950’s. Spray dates during the study period were September to December each year from 1999 to 2003. The application rate was 2g per m2.
House spraying with DDT in South Africa began in the 1950’s. In 1996, the policy changed to the exclusive use of a pyrethroid. After the emergence of pyrethroid insecticide resistance in the late 1990’s, DDT spraying was re-introduced for traditional structures in KwaZulu-Natal in February 2000 followed by a second round in June 2000 and in October for each of the subsequent years. The application rate was 2g per m2. DDT was re-introduced for house spraying in Mpumalanga Province, South Africa, in October 2001 and in Limpopo Province in October 2002.
All spraying was conducted throughout using Hudson expert pump sprayers with 8001 nozzles. Spraying personnel and managers were trained in spraying techniques, safety measures and personal protection equipment appropriate to the insecticide.
Since effective malaria control requires both vector control and early effective treatment, the RMCC decided to extend their objectives to ensure that the best malaria treatment was introduced across the LSDI.
Previously chloroquine was used as first line treatment and Sulphadoxine/pyrimethamine (SP) as second line treatment in both Swaziland and Mozambique, while in South Africa, SP was used as first line treatment. However, growing resistance to both chloroquine and SP has been an important contributor to the increased malaria morbidity and mortality across Africa, including southern Africa.
Comprehensive baseline evaluations included:
monitoring of therapeutic efficacy,
drug availability and use,
community perspectives on malaria treatment
and an economic evaluation of costs and cost effectiveness
These studies provided evidence for selection and implementation of the most effective malaria treatment available. They identified high levels of SP treatment failure as a major contributor to the malaria epidemic in KwaZulu Natal and prompted the rapid change in treatment policy by the Provincial Malaria Control Programme to an artemisinin-based combination therapy (ACT), artemether-lumefantrine (AL) in January 2001.
Widespread use of ACT offers the benefits of not only improving cure rates, but, unlike other malaria treatments, of also directly decreasing malaria transmission and potentially slowing drug resistance. To optimise the synergistic effects of indoor residual spraying (IRS) and ACTs on reducing malaria transmission and thus disease burden, while minimising programme costs, the implementation of ACTs has been timed to follow the establishment of effective vector control.
KwaZulu-Natal was the first Ministry of Health in Africa to implement an ACT malaria treatment policy, when it introduced Coartem in January 2001. The planned phased implementation of ACTs, which resulted in their introduction in Mpumalanga in 2003 and in two districts in southern Mozambique in 2004, is ahead of schedule and will ensure that ACTs will be in place throughout the LSDI region by 2006.
Evaluation of direct impact
The effectiveness of the malaria control programme in the long-term will be assessed by the incidence of malaria over time in Mozambique as well as in the neighbouring malarious areas of South Africa and Swaziland. The success of intervention is not only measured using process (e.g. spraying and artemisinin-based combination therapy coverage) and biological markers (e.g. parasite prevalence rates, health facility patient numbers and mosquito vector reductions), but also by the effects on tourism (e.g. bed occupancy, job creation and risk perceptions) in all three countries over the course of the 7 year period (2000 – 2007).
Parasite prevalence in children under 15 years of age was chosen as the principal indicator of the effectiveness of the programme in its early and middle phases. Once prevalence reaches sustained low levels, incidence of malaria cases will become more important as an indicator of the effectiveness of the malaria control measures. The regional malaria information system was developed towards measuring incidence.
Cross-sectional parasite surveys were performed by the respective country malaria control programmes at sentinel sites in the four Zones in Mozambique to which malaria control was extended (See map), and in South Africa and Swaziland at sentinel sites within 10 kilometres of the Mozambique border. Rapid diagnostic tests (HRP-2 antigen tests, ICTTM and Kat Medical) were used to assess prevalence of infection. Giemsa-stained thick bloodsmear films were collected from the 1155 survey respondents from the Mozambican sentinel sites and examined by skilled microscopists for validation of the antigen test.
At each of the 26 Mozambican sites, at least one survey was conducted prior to the intervention to provide estimates of pre-spraying baseline prevalence of infection. Initial parasite prevalence surveys were conducted in the respective zones in Mozambique in December 1999 (Zone1), June 2000 (Zone 1 and 1A), June 2002 (Zone 2) and June 2003 (Zone 3) with post-intervention assessment in June of each subsequent year. Parasite prevalence surveys were carried out in KwaZulu-Natal in December 1999, in June 2000, and in February and June 2001. In Swaziland, surveys were done in December 1999 and in June of each year thereafter. All age categories were sampled, with the exception of the surveys in Mozambique after December 1999, which were confined to children 2 to <15 years of age.
Results from the first prevalence survey revealed that there was a marked difference in prevalence between the three countries. The lowest infection rates were recorded in Swaziland where the prevalence ranged from 1 to 5%; in KwaZulu-Natal, it was found to be between 9 and 42%; and in Mozambique from 22 to 90%.
Vector species, numbers and infectivity were monitored at 26 sentinel sites using mosquito counts in 134 exit traps on a daily basis in the Mozambique sector.
Data have been collected at baseline and biannually, including the data on the following endpoints: in vivo therapeutic efficacy, drug utilisation, safety of anti-malarials (and other medicines), and costs to the public sector provider and cost effectiveness.
Information on the following was also collected in selected surveys:
Entomological data ( vector densities, insecticide susceptibility);
Knowledge, Practices and Behavior (KAP) of the affected communities
Malaria case totals (laboratory-confirmed) for Swaziland and South Africa were available from the MIS in these countries. The MIS document malaria cases diagnosed at health facilities, which include active case detection in South Africa. The system has been extended to Swaziland and implementation is well under way in southern Mozambique where it supports the phased implementation of definitive diagnosis and ACTs.
Impact of Malaria Control Programme
The extension of malaria control to the Mozambique sector has had the effect of dramatically reducing disease transmission in this area and has also resulted in a significant reduction in transmission in the highest risk malaria districts in South Africa (Ingwavuma and Komatipoort) and in Swaziland.