Battling malaria drug resistance along the Thai-Cambodian border
The project started in 2009 and one year later has achieved a number of key milestones.
Mosquito net coverage
The project has procured and distributed more than half a million long-lasting insecticide-treated mosquito nets. These high-quality bednets are designed to be effective, without further treatment, for up to five years. In zone 1, more than 260 000 have been distributed and this means every person in the zone is able to sleep under a mosquito net each night. This represents a ratio of one net for every two people. In zone 2, where 320 000 nets have been distributed, 100% coverage has also been achieved in the high-risk villages. A further 200 000 existing nets have also been retreated with insecticide. A follow-up assessment in Cambodia found that 70% of the nets were being regularly used. In Thailand, 100% coverage was achieved in all endemic villages, and 73% of recipients were regularly using them. On-going education in the target villages is expected to gradually increase the usage rate, but this level of use is believed to have a significant impact on the spread of malaria.
Ban on artemisinin-based single drug treatments introduced
The Cambodian Department of Drugs and Food, with support of the Minister of Health, issued a ban on artemisinin-based single-drug treatments (monotherapies) on 23 March 2009. All private pharmacies, shops and outlets dispensing drugs in Pailin province have been registered and are regularly inspected. Workshops have been held with drug outlet operators to raise awareness of the ban and the problems associated with monotherapies, among other issues. The response has been good with vendors voluntarily co-operating.
Anti-counterfeit drug police trained
Through the project 250 “justice police” have been trained to enforce the law against counterfeit drugs and the newly-introduced ban on the sale of monotherapies. These special police conduct regular systematic inspections of pharmacies and other outlets. There are also field and laboratory checks of drugs for authenticity. Combined with this, through the project, the Cambodian Government has worked with private operators to try to ensure that they are trained to use reliable diagnosis techniques and dispense only recommended drugs.
Reliable village-based diagnosis and treatment services established
All villages in zone 1 and all high-risk villages in zone 2 now have free early diagnosis and treatment services provided by fully trained and equipped village malaria workers. Each of the high-risk villages in both Cambodia and Thailand has two village malaria workers to ensure the services are available when needed. Previously, many villagers bought malaria drugs in the market, without any proper diagnosis. About 2 900 volunteer village malaria workers have been trained in Cambodia and 326 in Thailand. By making these services available for free in the village, the project is helping move malaria treatment from the private to the public sector, where only recommended drugs are dispensed.
Awareness campaigns conducted
Intensive community-based education programmes have been conducted throughout zones 1 and 2, raising awareness about reliable prevention practices like the use of mosquito nets, the dangers of fake drugs, and how to access reliable treatment. This has been provided through more than 3 000 village malaria workers who have been trained to educate their community. Education materials like posters, brochures, billboards have been produced in both Thai and Khmer, with the Khmer materials available on both sides of the border.
National Task Forces have been established in Thailand and Cambodia, and an International Task Force - comprising malaria experts and the chairs of the national task forces - has been set up to provide technical oversight and monitoring of the project. Two meetings of the International Task Force have been held, the first in Phnom Penh and the second in Hanoi in February 2010.
Robust monitoring and evaluation
A robust monitoring and evaluation framework has been established; regular surveys of households and drug outlets are conducted in order to assess the effectiveness of the project’s activities. For example, residents are interviewed as to their use of mosquito nets and village malaria workers, and on their understanding of malaria.
Cross border surveillance
Systems to monitor the cross-border movements of Cambodians (mostly) and Thais have been developed to aid efforts to track possible movement of the malaria parasites. The health departments of Cambodia and Thailand are sharing information to co-ordinate actions and to enable effective follow-up of cases.
Intense screening piloted
An intense screening and treatment programme is being conducted in 20 high-risk villages in Pailin. The programme aims to screen all men, women and children in a village, even those not showing any symptoms of malaria. Samples are sent by taxi to the Pasteur Institute in Phnom Penh where sophisticated technology – polymerase chain reaction (PCR) - is used to determine with high accuracy whether a person has malaria. PCR can detect even a single parasite in a blood sample. Through the programme an entire village can be screened with results back to the village within days, so any positive cases can be followed up and effectively treated. Through the process valuable information is gathered on patterns of infection, and the risk of resistant parasites spreading.
Encouraging early results
Initial results from the intense screening programme in 20 high-risk villages found that the strain of malaria that has shown resistance to artemisinin, falciparum malaria, has almost disappeared from the villages tested. In the first seven villages screened – from May to late June 2010 - almost 2 800 people were tested and only two cases of falciparum malaria were found. Six of the seven villages had no cases of falciparum malaria. Only last year these seven villages were among the most affected by malaria in the border area. This screening was carried out approximately one year after a range of interventions were rolled out to combat malaria in the target area. These results suggest that the interventions are working. Two other sources of data – from the Cambodian Ministry of Health and from the village malaria workers – also found that cases of falciparum malaria in the zone targeted by the project had fallen dramatically.
Intensive surveillance of resistant cases
New systems to intensely monitor and investigate all cases still positive after three-days’ of treatment (indicating possible resistance) are being piloted, particularly in Cambodia. Monitoring of cases of falciparum malaria still present after three days of treatment has been introduced at seven key sites – six hospitals and a health centre – and will be extended down to the village level after further training of the village malaria workers. Cases still positive after three days of treatment will be further treated and closely monitored for 28 days. This will enable any drug tolerance to be closely mapped and assessed, and ensure the parasites are killed. Further, mosquito control activities are stepped up in the vicinity of the homes of those found to be carrying tolerant or resistant parasites. In Thailand, all positive malaria cases are followed up for a period of 28 days. This ensures treatment is effective and enables monitoring of any tolerance or resistance to artemisinin.
Studies on patterns of migration in the project area have been conducted. Cambodia, particularly, has both a considerable internal and cross-border mobile population. About 3.4 million Cambodians migrate internally each year alone, mainly for seasonal work. This research is important for informing strategies to reach the cross-border and internal migrants, and understand the risks of parasite movement.