Case reporting within 24 hours
All individuals who test positive for malaria using microscopy or a rapid diagnosis test (RDT) receive malaria treatment according to the national treatment guidelines and trigger the start of the 1-3-7 surveillance process. All malaria species are included in 1-3-7 surveillance efforts, with Plasmodium falciparum and Plasmodium vivax being most common in Thailand [8]. Health care providers were already required to report confirmed cases and laboratory results under Thailand’s malaria control strategy [8]; this was adjusted for the elimination program to include a requirement to complete the notification within 24 hours (1 day) of diagnosis [15]. An optional cellphone-based short message service alert system immediately informs district-level staff of a case, ensuring timely follow-up. Providers may also choose to report cases using the traditional paper form.
Case investigation and classification within 3 days
Thailand has long conducted malaria case investigations to identify risk behavior and to classify cases as imported or indigenous. Under the NMES, the MOPH adopted an enhanced case classification to allow a more precise understanding of where the patient contracted the disease and identify a source of transmission from remaining hotspots. Thailand’s case investigation form (EP3) includes minimal essential data (e.g., demographics, illness history, diagnostic results, treatment, travel history) and likely location of infection. Cases are investigated by malaria clinic workers, district officers, or provincial officers and are classified per the criteria in Table 1 [4].
Table 1. Case classification in Thailand
Case classification
|
Current definition
|
A
|
Indigenous case, a patient who contracted malaria in the village where the patient lived during infection period
|
B
|
Imported case, a patient who contracted malaria from another area. Place of infection must be identified at village level
|
Bx
|
Contracted malaria from another village but within the same subdistrict
|
By
|
Contracted malaria from another subdistrict but within the same district
|
Bz
|
Contracted malaria from another district but within the same province
|
Bo
|
Contracted malaria from another province
|
Bf
|
Contracted malaria from abroad
|
C
|
Relapse case, a Plasmodium vivax or Plasmodium ovale patient who had a malaria episode and has recurrent fever that is not a new infection
|
D
|
Induced case, a patient who received malaria parasites from blood transfusion
|
E
|
Introduced case, a patient who contracted malaria with evidence connecting the case to an imported case
|
F
|
Unclassified case where, after investigation, staff are unable to determine a whether the patient is A or B
|
G
|
Uninvestigated case, a patient that staff unsuccessfully attempted to investigate
|
Case investigation data are recorded on a paper form that is then uploaded to a national repository in the MIS. If the conclusive case classification is “A,” a focus investigation is warranted, and the surveillance rapid response teams (SRRT) deploys the focus investigation and response.
Foci investigation and response within 7 days
Thailand’s foci investigation compiles epidemiological, entomological, and sociological information and the results of past interventions. This allows local health authorities to identify causes and characteristics of indigenous transmission to deploy appropriate interventions. With the NMES, Thailand adopted a new foci stratification with four categories according to level of transmission, as outlined in Table 2 [16].
Table 2. Foci classification in Thailand
Foci classification
|
Current definition
|
A1
|
Active foci: Village with indigenous cases in the current year
|
A2
|
Residual non-active foci: Village without indigenous cases in the current year but with indigenous cases in the previous 3 years
|
B1
|
Cleared foci but receptive: Village without indigenous cases for 3 consecutive years but vectors are found or environment is suitable for vector breeding
|
B2
|
Cleared foci but not receptive: Village without indigenous cases for 3 consecutive but vectors are not found or environment is not suitable for vector breeding
|
Thailand’s adoption of the NMES also reoriented foci investigation in two ways. Firstly, a strict timeline to conduct the investigation within 7 days of case investigation was required. Secondly, in active foci (A1 and A2 areas) where all interventions are applied but malaria cases persist for over 4 consecutive weeks, reactive case detection (RACD) is conducted (Table 3). RACD is a surveillance response initiated when an indigenous index case is found in a village (foci) with transmission (A1 or A2) or without transmission but with the presence of a suitable vector (B1). Blood is taken for microscopy from all members living in the index patient’s house and all neighbors living around the index patient’s house, aiming for at least 50 blood samples or 10 households within a 1-kilometer radius. Additional foci response activities include vector control (distributing ITNs to reach 90% coverage at 1 bed net per 2 persons or indoor residual spraying [IRS] of at least 90% of households) and health education [4]. These data are stored in the MIS in a designated foci registry.
Enhancing surveillance infrastructure for elimination
Malaria Online was introduced in 2012 to facilitate case-based surveillance data tracking through online and offline reporting. The MIS comprises real-time malaria case data, geospatial foci and vector mapping, and drug efficacy data. It also serves as a resource portal for policies and strategic documents related to malaria. The MIS collates two main sources of malaria case recording and reporting (Figure 2):
- The vertical malaria program, starting from subdistrict malaria clinics (MCs) through provincial Vector Borne Disease Centers (VBDCs). These health facilities record data on paper forms for case notification and case investigation; district health teams then input the data into the MIS.
- The general health services (GHS) program, starting from community-level malaria posts (MPs) and hospitals (all types) through Provincial Health Offices (PHOs) to the Bureau of Epidemiology (BOE) [8]. These health facilities record data in a separate system maintained by the BOE.
Thailand is currently in a semi-vertical approach for malaria elimination as these two reporting lines are being integrated. Regardless of data type, 1-3-7 guidelines for timeliness of reporting are enforced.
In 2016, new features were added to enable real-time monitoring at every level of the health system and to encourage local staff to take ownership of their data and use the results to improve intervention targeting. The DVBD installed dashboards and visualizations in the MIS to show geospatial mapping of the 1-3-7 metrics, RACD targets and achievements, and a summary of the 1-3-7 malaria elimination strategy (Figure 3). A new 1-3-7 dataset, representing information from the weekly and monthly reports generated by provinces, includes the number of malaria cases reported and the proportion reported within 1 day, the number of cases investigated and the proportion investigated within 3 days, and the number of foci investigations (with RACD) and the proportion investigated within 7 days.
To encourage local staff to adopt 1-3-7 protocols and use the resulting data, the DVBD also created a weekly report that collates data highlights.
By allowing for timely analysis of malaria surveillance and case investigation data, Malaria Online supports Thailand’s goal to use surveillance to develop strategic information that leads to appropriate action. A Business Intelligence add-on to the MIS facilitates comparisons of weekly incidence across years. If case numbers are higher than expected, the DVBD or provincial authorities alert the relevant subdistricts to consider appropriate investigation and control activities. In the example below, Prachuab Khiri Khan province received notice during the 27th week of the year that there were 20 more cases reported than in the same week the previous year (Figure 4). The notice included a dropdown list of villages; the action required to find out which areas were affected; and instructions for prompt case re-investigation, focus investigation with RACD of the whole village, and renewed vector control measures in line with the 1-3-7 strategy. Subnational officers took prompt action during the 27th week, with new cases triggering additional case investigations and a wider response until the next week witnessed a decreasing number of malaria cases.
For data to inform more granular operational decision-making as malaria burden decreases, data must be timely and accessible to subnational officers, health workers, and community focal persons. However, in the remaining hotspot locations in Thailand internet access may be unreliable and therefore prevents access to submitting and obtaining data in real time. To address these disadvantages, at the provincial and district levels the MIS can access and store back-up data in the Malaria Offline database in a central server [8]. Malaria Offline complements Malaria Online to ensure that work can continue during internet outages and that key staff can access their data.
Human resources for strong surveillance
Malaria surveillance for elimination in Thailand relies on human resources in both the malaria vertical program and the GHS system (Table 4). The surveillance system also engages village health volunteers (VHVs) for community reporting on 1-3-7 metrics. Some Vector Borne Disease Units (VBDUs) supervise GHS staff to ensure high-quality malaria case detection, surveillance, and response.
Day 1 malaria cases could be found and notified by staff from MCs, MPs, or border posts or by general health facility clinicians. Day 3 case investigations are conducted by MC staff or sometimes by public health workers at hospitals or MP staff with additional follow-up from SRRTs. Day 7 foci investigation and response largely relies on district-level SRRTs, a national system of epidemiology and investigation teams established in 2004 [18]. SRRT members include staff of both the vertical and GHS programs.
Both the DVBD and BOE remain committed to building skills and updating training materials and guidelines for effective implementation of the elimination program and the 1-3-7 strategy. The training package targeted epidemiologists, malaria surveillance focal points, and entomologists and was complemented by annual refresher training [13]. Public health workers trained all epidemiologists as part of the SRRT launch in each province to integrate malaria elimination activities into their work, including the 1-3-7 strategy and other public health responses. The training, comprising both workshops and on-the-job coaching, covered MIS data monitoring for timely action to correctly identify malaria infections and disrupt transmission. Since the launch of the 1-3-7 strategy, the DVBD has conducted annual trainings, resulting in 719 trained epidemiologists in Thailand. At the subdistrict and community levels, training for healthcare providers included VHVs. Entomologists were trained on vectors present in each subdistrict or VBDU area, a collection of mosquitoes for polymerase chain reaction (PCR) testing to rule out indigenous transmission in new B1 areas prior to their designation, and insecticide resistance monitoring for endemic areas.
Allocating budget and resources
Costs for surveillance and response activities, including required equipment, internet connectivity, and labor are supported through the MOPH budget, the health security budget, and local budgets. This domestic funding is enhanced by support from the Global Fund to Fight AIDS, Tuberculosis, and Malaria and additional external support from partners such as the United States President’s Malaria Initiative. The MOPH also works with other agencies to coordinate malaria activities in their relevant domains and identify efficiencies, prioritize tailored activities, and maximize available funding. For example, shared information technology and systems resources across the government support malaria surveillance efforts.
From 2017 to 2020, the MOPH supported the malaria elimination strategy with Thai baht 2.8 billion (USD $88.5 million), which does not include budget spent for health infrastructure and human resources [5]. The Malaria Elimination Steering Committee, comprising members from several ministries and WHO, develops an integrated budget. Of this budget, 11% is allocated to surveillance activities.
At the local level, PHOs and Local Administrative Organizations (LAOs) in areas with malaria transmission may allocate their own funds to malaria elimination projects. LAOs have subdistrict-level responsibility for public health and welfare issues, including malaria [5, 17]. The 2015 Infectious Disease Act also stipulates that LAOs must conduct malaria surveillance and liaise with district health authorities. LAO committees that prioritize malaria as a community issue are empowered to design projects on disease control and response, based on hyperlocal malaria epidemiology and surveillance data. They also prepare and approve annual budget plans, and they manage funds for emergencies like disease outbreak response or natural disasters.
Comparisons between the Thailand experience and the China experience
The DVBD adopted the 1-3-7 strategy from China but tailored the strategy’s activities to suit Thailand’s requirements, available resources, and surveillance infrastructure. China included all suspected malaria cases in surveillance activities, which required substantial resources despite the country’s low caseload at rollout in 2012 [19]. In Thailand, because all suspected malaria patients can access blood tests and results within the same day of visit, only confirmed positive cases trigger the 1-3-7 strategy. This not only promotes accurate management of fever patients and efficient use of commodities but also increases the quality of surveillance data by reducing reporting requirements.
Microscopy examination remains the most widely used diagnostic tool for laboratory confirmation of malaria both in Thailand and China. However, with declining incidence, practitioners’ skills in performing and reading blood smears may decrease [9], so RDTs have recently become available in primary health care centers and communities in Thailand. This will allow VHVs to play a greater role in Thailand’s malaria elimination strategy compared with China and also supports Thailand’s system based on confirmed cases rather than suspected cases [20].
Foci classification also varied between the two countries, with four categories in Thailand and three categories in China. In China, areas with at least one confirmed malaria case are classified into three foci categories:
- “Inactive focus” is an area that is unlikely to support transmission because of an absence of vectors;
- “Active focus” is an area with suitable vectors; and
- “Pseudo focus” is a malaria-free area with a case classified as imported [9, 20].
Thailand has been using a foci classification system for several years, throughout both the malaria control and malaria elimination phases, based on malaria source (i.e., indigenous or imported), entomological factors, and environmental characteristics (i.e., unsuitable or suitable for transmission) [7]. Whereas in China both active and pseudo foci prompt RACD, in Thailand RACD screening is carried out only in foci with an index case (A1, A2, or B1).
Recording and reporting requirements were also slightly different because Thailand looked for efficiencies to maximize limited resources. In Thailand, to meet the criteria for foci reporting within 7 days, MIS users may input data through the end of the subsequent week that the case was reported. For example, if the case was identified on Monday of week 1, the VBDU can respond on any day starting on Monday of week 1 through Saturday (i.e., the last day) of week 2. As long as there were no other cases occurring in the same sub-village that week, the MIS will count that case as responded to within 7 days. Because workload for subnational officers can often be a bottleneck to timely surveillance and response, the DVBD applied a workload reducing strategy based on the number of cases in a province. For example, in a high-prevalence province like Tak, which reported 1,685 malaria cases in 2019, only one RACD was required even if more than one index case was reported at the same week in the same sub-village. Because each RACD targets 50 people per index case, coverage was adequate to maintain high-quality surveillance.
Success factors to Thailand’s 1-3-7 surveillance strategy
The DVBD has heightened the visibility of malaria in Thailand by coordinating a Malaria Steering Committee and working across various government agencies including the Ministry of Interior, Ministry of Foreign Affairs, and Ministry of Defense. To engage policymakers, the team outlined a convincing argument that focused on the benefits of malaria elimination for the development of the country—for example, the DVBD published a cost-benefit analysis that found that every Thai baht invested in malaria elimination can return up to 15 Thai baht to Thailand’s health system, households, and economy [21]. The DVBD also partnered with neighboring countries to share data and policies; this regional approach opened new funding opportunities through the Global Fund Regional Artemisinin-resistance Initiatives. More internally, the DVBD has prioritized malaria surveillance, including the 1-3-7 strategy, in its strategies and budgets, creating an enabling environment from Thailand’s public health leadership. Supporting digital transformation policies have simultaneously catalyzed malaria surveillance infrastructure and success, including developing dashboards that facilitate review of 1-3-7 metrics and catalyze subsequent actions.
At the operational level, Thailand’s malaria officers also have a mobile chat application that is a unique factor in the success of 1-3-7 surveillance. The chat group has over 400 malaria members from across the country and at every level of the health system. The group chat enables continual communication with peers to monitor the malaria situation, exchange experiences, seek recommendations or troubleshooting support, share press releases, and provide fodder for new strategies. Participation of the DVBD and national-level partners also supports more effective monitoring and evaluation. The active members respond to notifications, ask questions and provide answers, and offer motivation and support, making it an efficient platform for monitoring and communication among malaria workers.
A final success factor in Thailand’s implementation is the flexibility of implementing budgets and activities at very local levels. Even though annual budgets are calculated based on the previous year’s activities and unexpected situations often occurred, LAOs were able to work with provincial authorities to revise their local budgets to fit needed activities for the current situation. Because these local authorities know the community situation, this microplanning has been a successful strategy for organizing targeted response even in situations with unanticipated spikes in malaria caseload.
The future road to elimination
The 1-3-7 strategy has been successfully implemented, and results suggest it has contributed to Thailand’s decline in malaria burden from 14,948 cases in fiscal year 2017 to just 4,421 in fiscal year 2019, representing a 70% reduction in incidence. The DVBD continues to adapt its program to ensure prompt and high-quality case management, capacity maintenance, and adequate supply of lifesaving commodities. It is also continuing routine data monitoring and wider assessments as needed to verify that the time-bound targets of the 1-3-7 strategy are sustained over time. Senior staff are expanding technical discussions and resources to include prevention of reintroduction. However, the DVBD may also need to consider potential challenges that may emerge as provinces approach very low prevalence.
The MOPH is working toward an integrated system of health services by phasing out vertical VBDUs, VBDCs, and MCs. As staff in these facilities retire, the MOPH is not recruiting replacements so that future patients are directed toward GHS facilities, including health promoting hospitals [13]. The new structure of GHS’s malaria program is semi-vertical, with the DVBD’s expertise guiding the development of high-quality malaria services across facility types. This guidance includes incorporation of malaria case management into GHS pre-service training, mechanisms of in-service training and professional support through VBDU, and an encouraging career path for GHS trainees [5, 8]. The DVBD will remain involved in the integration process to ensure the high quality of malaria case management and surveillance is maintained through elimination and prevention of reintroduction.
When areas reach very low prevalence, the DVBD may consider supporting provincial authorities to take a stronger role in quality assurance. Additional online training and standard operating procedures could support a more decentralized system to fortify comprehension of protocols despite current challenges caused by the coronavirus disease. An annual online training with certification could be one way to maintain knowledge and skills, share updates, and review surveillance data as fewer health staff interact with suspect malaria cases and have robust malaria case management experience.
As the DVBD’s efforts reduce malaria burden, advocating for necessary funds becomes more challenging. Thailand’s budget for malaria surveillance has changed over time. However, the technical malaria community knows that malaria elimination programs are more resource-intensive than malaria control, with increasing cost per case. The current global funding landscape is shifting, and external funds available to Thailand are shrinking. This challenge requires the DVBD to be more creative and strategic with identifying sources of financial support. Especially in the described climate of integration, domestic fund-raising is also a challenge because it requires that malaria be prioritized over all other diseases Thailand is working to address.
Table 3. Implementation of the 1-3-7 strategy for malaria elimination
1-3-7 strategy
|
Activities
|
Case notification (within 1 day)
|
Confirmed malaria cases
|
Area classification
|
Active foci
(A1)
|
Residual non-active foci (A2)
|
Receptive foci (B1)
|
Non-receptive foci (B2)
|
Case investigation and classification (within 3 days)
|
Indigenous/Imported
|
Indigenous/Imported
|
Imported
|
Indigenous
|
Imported
|
Foci investigation and response (7 days)
|
Surveillance
|
- RACD 50 people/10 HHs 1–2 kilometers
- PACD (2 rounds/year)
- Foci investigation (persistent indigenous cases)
|
- RACD 50 people/10 HHs 1–2 kilometers
- PACD (1 round/year)
- Foci investigation (if an indigenous index case is reported)
|
- RACD 50 people/10 HHs 1–2 kilometers
- Re-investigation & confirmation
|
- RACD in whole village and cluster screening
- Re-investigation & confirmation
- Foci investigation
- Confirm new focus
|
- Continue surveillance
|
Diagnosis
|
- Communitya (RDT/Microscopy)
- Public health facilityb (Microscopy)
|
- Community (RDT/Microscopy)
- Public health facility (Microscopy)
|
- Public health facility (Microscopy)
|
- Community (RDT/Microscopy)
- Public health facility (Microscopy)
|
- Hospitals (Microscopy)
|
Treatment and follow-up
|
- Supervised treatment
- Case follow-upc
|
- Supervised treatment
- Case follow-up
|
- Supervised treatment
- Case follow-up
|
- Supervised treatment
- Case follow-up
|
- Supervised treatment
- Case follow-up
|
Vector control
|
- Vector survey
- ITNs or IRS (90% coverage)
- LLIN (1 per 2 persons)
|
- Vector survey
- ITNs or IRS (90% coverage)
- LLIN (1 per 2 persons)
|
- Vector survey
|
- Vector survey
- ITNs or IRS (90% coverage)
- LLIN (1 per 2 persons)
|
|
|
|
|
|
|
|
|
|
HH, household; IRS, indoor residual spraying; ITN, insecticide-treated net; LLIN, long-lasting insecticide-treated bed net (includes ITNs, retreated bed nets, and hammocks); PACD, proactive case detection; RACD, reactive case detection; RDT, rapid diagnosis test.
a Malaria posts and malaria clinics; b Health promoting hospitals and district, provincial, and regional public hospitals; c Follow-up and re-testing for P. falciparum and P. vivax cases according to national guidelines.
Table 4. Roles and responsibilities in implementing the 1-3-7 strategy
Country level
|
Ministry of Public Health
|
Central level
|
Division of Vector Borne Diseases,
Department of Disease Control
|
Department of Epidemiology
|
- Make policy decisions
- Supervise, monitor, and evaluate interventions
- Integrate data from all sources to the MIS database
- Cross-check and analyze data; share feedback
- Share feedback with and support subnational staff
- Provide technical support for the MIS and Malaria Offline
- Collaborate with Department of Epidemiology as C-SRRT
|
- Make policy decisions
- Cross-check and analyze data
- Share feedback with and support subnational staff
- Collaborate with Department of Disease Control as C-SRRT
|
Provincial level
|
Vector Borne Disease Centers
- Enter and upload data (Days 1, 3, 7) into Malaria Offline program
- Supervise, monitor, and evaluate interventions
- Monitor provincial MIS data and facilitate reporting and feedback
- Collaborate with Provincial Health Office as P-SRRT
|
Provincial Health Offices
- Supervise, monitor, and evaluate interventions
- Monitor provincial data and facilitate reporting and feedback
- Collaborate with Vector Borne Disease Center as P-SRRT
|
District level
|
Vector Borne Disease Units
- Enter and upload data (Days 1, 3, 7) into Malaria Offline program
- Supervise, monitor, and evaluate interventions
- Monitor district MIS data and facilitate reporting and feedback
- Collaborate with District Health Office as D-SRRT
- Day 1: Send malaria case reports (EP1) to provincial and central levels
- Day 3: Complete case investigation and classification; send EP3 form to district level
|
District Health Offices
- Enter data into HosXP reporting program
- Supervise, monitor, and evaluate interventions
- Monitor district data and facilitate reporting and feedback
- Collaborate with Vector Borne Disease Units as D-SRRT
|
District Hospitals
- Conduct malaria testing, treatment, and follow-up
- Day 1: Send malaria reports (R506) to District Health Office
- Day 3: Complete case investigation and classification; send form to Department of Epidemiology
- Collaborate with Vector Borne Disease Units as D-SRRT
|
Subdistrict level
|
Malaria Clinics
- Conduct malaria screening, testing, treatment, and follow-up
- Day 1: Send malaria case reports (EP1) to district level
- Day 3: Complete case investigation and classification; send EP3 form to district level
- Day 7: Conduct foci investigation and RACD as L-SRRT
|
Health Promoting Hospital, Health Centers
- Supervise, monitor, and evaluate interventions
- Conduct malaria testing, treatment, and follow-up
- Day 1: Send malaria reports (R506) to district level
- Day 3: Complete case investigation and classification; send form to Department of Epidemiology
- Day 7: Conduct foci investigation and RACD as L-SRRT
|
Community or village level
|
Malaria Posts and Border Malaria Posts
- Conduct malaria screening, testing, and follow-up
- Day 1: Send malaria case report (EP1) to district level
- Day 7: Support L-SRRT
|
Village Health Volunteers
- Conduct malaria screening, testing, and follow-up
- Day 1: Send malaria case report (EP1) to district level
- Day 7: Support L-SRRT
|
EP1, Malaria Blood Examination form; EP3, Investigation and Radical Treatment of Malaria case form; R506, Disease Surveillance Report form; D-SRRT, District-SRRT; L-SRRT: Local-SRRT; MIS, malaria information system; SRRT, Surveillance Rapid Response Team; P-SRRT, Provincial-SRRT.