First malaria in pregnancy followed in Philippine real-world setting: proof-of-concept of probabilistic record linkage between disease surveillance and hospital administrative data.

BACKGROUND: Although the Philippines targets malaria elimination by 2030, it remains to be a disease that causes considerable morbidity in provinces that report malaria. Pregnant women residing in endemic areas are a vulnerable population, because in addition to the risk of developing severe malaria, their pregnancy is not followed through, and the outcome of their pregnancy is unknown. This study determined the utility of real-world data integrated with disease surveillance data set as real-world evidence of pregnancy and delivery outcomes in areas endemic for malaria in the Philippines. METHODS: For the period of 2015 to 2019, electronic data sets of malaria surveillance data and Ospital ng Palawan hospital admission log of pregnant women residing in the four selected barangays of Rizal, Palawan were merged using probabilistic linkage. The source data for record linkage were first and last names, birth date, and address as the mutual variable. The data used for characteristics of the pregnant women from the hospital data set were admission date, discharge date, admitting and final diagnosis and body weight on admission. From the malaria surveillance data these were date of consultation, and malaria parasite species. The Levenshtein distance formula was used for a fuzzy string-matching algorithm. Chi-square test, and Mann-Whitney U test were used to compare the means of the two data sets. RESULTS: The prevalence of pregnant women admitted to the tertiary referral hospital, Ospital ng Palawan, was estimated to be 8.34/100 overall, and 11.64/100 from the four study barangays; that of malaria during pregnancy patients was 3.45/100 and 2.64/100, respectively. There was only one true-positive matched case from 238 women from the hospital and 54 women from the surveillance data sets. The overall Levenshstein score was 97.7; for non-matched cases, the mean overall score was 36.6 (35.6-37.7). The matched case was a minor who was hospitalized for severe malaria. The outcome of her pregnancy was detected from neither data set but from village-based records. CONCLUSIONS: This proof-of-concept study demonstrated that probabilistic record linkage could match real-world data in the Philippines with further validation required. The study underscored the need for more integrated and comprehensive database to monitor disease intervention impact on pregnancy and its outcome in the Philippines.

Enhanced Health Facility Surveys to Support Malaria Control and Elimination across Different Transmission Settings in the Philippines.

Following substantial progress in malaria control in the Philippines, new surveillance approaches are needed to identify and target residual malaria transmission. This study evaluated an enhanced surveillance approach using rolling cross-sectional surveys of all health facility attendees augmented with molecular diagnostics and geolocation. Facility surveys were carried out in three sites representing different transmission intensities: Morong, Bataan (pre-elimination), Abra de Ilog, Occidental Mindoro (stable medium risk), and Rizal, Palawan (high risk, control). Only one rapid diagnostic test (RDT)-positive infection and no PCR confirmed infections were found in Bataan and Occidental Mindoro, suggesting the absence of transmission. In Palawan, the inclusion of all health facility attendees, regardless of symptoms, and use of molecular diagnostics identified 313 infected individuals in addition to 300 cases identified by routine screening of febrile patients with the RDT or microscopy. Of these, the majority (313/613) were subpatent infections and only detected using molecular methods. Simultaneous collection of GPS coordinates on tablet-based applications allowed real-time mapping of malaria infections. Risk factor analysis showed higher risks in children and indigenous groups, with bed net use having a protective effect. Subpatent infections were more common in men and older age-groups. Overall, malaria risks were not associated with participants' classification, and some of the non-patient clinic attendees reported febrile illnesses (1.9%, 26/1,369), despite not seeking treatment, highlighting the widespread distribution of infection in communities. Together, these data illustrate the utility of health facility-based surveys to augment surveillance data to increase the probability of detecting infections in the wider community.

The evaluation of operating Animal Bite Treatment Centers in the Philippines from a health provider perspective.

BACKGROUND: The Philippine government has an extensive network of 513 Animal Bite Treatment Centers (ABTCs) to supply rabies post exposure prophylaxis (PEP), reaching over 1 million bite victims in 2016. The network was evaluated using a review of existing national and provincial data, key informant interviews and surveys in sample ABTCs to determine the cost-effectiveness of this network in preventing human rabies deaths. METHODOLOGY AND PRINCIPAL FINDINGS: One urban and one rural ABTC in each of three selected provinces were studied in more detail. PEP delivery generally followed national guidance based on best practices, but there was evidence of operational challenges in supplying all ABTCs with adequate biologics and recently trained staff. Funding was contributed by different levels of government and in some clinics, patients paid for a significant fraction of the total cost. From a health provider perspective including both fixed and variable costs, the average PEP course delivered cost USD 32.91 /patient across urban ABTCs (with higher patient throughput) and USD 57.21 /patient across rural ABTCs. These costs suggests that PEP provision in the Philippines cost USD 37.6 million in 2016, with a cost per life saved of USD 8,290. An analysis of the 2,239 suspected rabies deaths from 2008 to 2016 showed no significant decline, and from 2014-16 an average of 8,534 years of life were lost annually. The incidence of rabies deaths from 2014-16 was not clearly related to the provision of ABTCs (per 100,000 population) or human population density, but deaths were more common in higher income provinces. CONCLUSIONS/SIGNIFICANCE: In the context of comprehensive rabies control (including dog vaccination and public awareness) ways to reduce this high expenditure on PEP should be explored, to most cost-effectively reach the elimination of human rabies deaths. This paper is accompanied by another containing data on the operation of ABTCs network from a patient perspective.

The evaluation of Animal Bite Treatment Centers in the Philippines from a patient perspective.

BACKGROUND: The Philippines has built an extensive decentralised network of Animal Bite Treatment Centers (ABTCs) to help bite victims receive timely rabies post-exposure prophylaxis (PEP) at little cost. This study surveyed patients in the community and at ABTCs of three provinces to assess animal bite/scratch incidence, health-seeking behaviour and PEP-related out-of pocket expenses (OOPE). METHODOLOGY AND PRINCIPAL FINDINGS: During community surveys in 90 barangays (neighbourhoods), 53% of households reported at least one animal bite /scratch injury over the past 3 years, similar across urban and rural barangays. Overall bite/scratch incidences in 2016-17 were 67.3, 41.9 and 48.8 per 1,000 population per year for Nueva Vizcaya, Palawan and Tarlac respectively. Incidences were around 50% higher amongst those under 15 years of age, compared to -those older than 15. Household awareness of the nearest ABTCs was generally over 80%, but only 44.9% sought proper medical treatment and traditional remedies were still frequently used. The proportion of patients seeking PEP was not related to the distance or travel time to the nearest ABTC. For those that did not seek medical treatment, most cited a lack of awareness or insufficient funds and almost a third visited a traditional healer. No deaths from bite/scratch injuries were reported. A cohort of 1,105 patients were interviewed at six ABTCs in early 2017. OOPE varied across the ABTCs, from 5.53 USD to 37.83 USD per patient, primarily dependent on the need to pay for immunization if government supplies had run out. Overall, 78% of patients completed the recommended course, and the main reason for non-completion was a lack of time, followed by insufficient funds. Dog observation data revealed that 85% of patients were not truly exposed to rabies, and education in bite prevention might reduce provoked bites and demand for PEP. An accompanying paper details the ABTC network from the health provider's perspective.

Cholera prevention and control in Asian countries.

Cholera remains a major public health problem in many countries. Poor sanitation and inappropriate clean water supply, insufficient health literacy and community mobilization, absence of national plans and cross-border collaborations are major factors impeding optimal control of cholera in endemic countries. In March 2017, a group of experts from 10 Asian cholera-prone countries that belong to the Initiative against Diarrheal and Enteric Diseases in Africa and Asia (IDEA), together with representatives from the World Health Organization, the US National Institutes of Health, International Vaccine Institute, Agence de médecine préventive, NGOs (Save the Children) and UNICEF, met in Hanoi (Vietnam) to share progress in terms of prevention and control interventions on water, sanitation and hygiene (WASH), surveillance and oral cholera vaccine use. This paper reports on the country situation, gaps identified in terms of cholera prevention and control and strategic interventions to bridge these gaps.

INVESTIGATION OF MOSQUITOES WITH EMPHASIS ON AEDES (FINLAYA) POICILIUS, PUTATIVE VECTOR OF BANCROFTIAN FILARIASIS ON PANAY ISLAND, THE PHILIPPINES.

Entomological investigations were conducted in four remaining lymphatic filariasis endemic provinces of Panay Island, The Philippines to determine mosquito species present in these areas and to identify host preference and biting activity of Aedes (Finlaya) poicilius Theobald, primary vector of nocturnal periodic Wuchereria bancrofti in The Philippines. Sampling techniques targeted nocturnally active mosquito species using a carabao-baited trap (CBT) and human-landing collection (HLC), the latter taking place from 06:00 to 12:00 pm. A total of 25,536 mosquitoes comprising 42 species and 7 genera were collected from CBT, whilst HLC acquired 6,486 mosquitoes comprising 28 species and 5 genera. Three known or potential vectors of human filarial were collected, namely, Aedes poicilius, Culex quinquefasciatus and Mansonia uniformis. The peak landing (biting) activity for Ae. poicilius was between 09:00 and 11:00 pm. Comparisons between CBT and HLC yields showed this species to be more zoophilic. Based on observed mosquito behavior and interviews with residents, vector-host contact was promoted by the local practice of staying overnight in makeshift shelters in high risk areas without adequate protection against mosquito bites. Results of this survey will augment information for integrating vector control and mass drug administration into an island-wide lymphatic filariasis elimination program.

World Rabies Day campaign in the Philippines.

BACKGROUND: Rabies is a fatal disease, claiming the lives of around 59,000 people annually worldwide. It is considered a neglected and underreported disease leading to inadequate support from governments. Apart from dog vaccination and proper animal bite management, an integral part of a successful rabies control program is community education. The Philippine government conducts an extensive nationwide annual World Rabies Day (WRD) celebration as part of its community education. METHODS: Strong inter-sectoral collaboration at the national level is a key factor for the success of WRD, capitalizing on the partners' strengths to mobilize various sectors. Strategies include the National WRD Celebration and releasing national government memorandums. An invitation letter campaign was initiated, encouraging stakeholders to register their activities. Banners were given as an incentive for those who registered. Mass and social media were also utilized to promote WRD. RESULTS: Registered WRD events held in the Philippines rose from 10 events in 2012, to 37 events in 2013, to 66 events in 2014 and 76 events in 2015. The individual activities involved veterinary services and information, communication, and education (IEC) activities. Nine unique WRD IEC activities are highlighted in this paper. Promotion of WRD through social media was also utilized in recent years. More news items were published online than those printed in newspapers and aired on television. CONCLUSION: The campaign's success underlines the value of a national government-led program. The national rabies program sets the agenda for priority activities including the WRD campaign. Its capacity to allocate funds for the program also denotes stability which is beneficial for local program implementers. Different segments of society were tapped through various strategies. The campaign's flexibility allowed for a large range of activities and presented opportunities for expanding partnerships and integration with others interventions for its sustainability. With appropriate tools and government support, the extensive WRD campaign in the Philippines can be replicated in other countries. The strategies discussed prove that since different localities celebrate WRD in their own way, other countries can also organize activities adapted to their culture and contribute to the global campaign against rabies.

BIONOMICS AND ECOLOGY OF ANOPHELES LITORALIS ON BONGAO ISLAND, TAWI-TAWI PROVINCE, PHILIPPINES: IMPLICATIONS FOR VECTOR CONTROL.

Entomological surveys were conducted to identify Anopheles malaria vector species, their feeding and resting behaviors, and characterization of larval habitats on Bongao Island, Tawi-tawi Province, in July and November, 2007. Survey parameters included all-evening human-landing collections (HLC), evening buffalo-baited trap (BBT) collections, daytime indoor and outdoor adult resting collections, adult female age-grading, identification of natural Plasmodium infections in mosquitoes, larval habitat identification and physical/biological characterization, and adult insecticide susceptibility assays. Both surveys revealed the predominant and putative malaria vector species on Bongao Island is Anopheles litoralis. Anophelesflavirostris was collected on only one occasion. The HLC during the July survey produced approximately 4 mosquitoes/human/night (mhn). The November survey yielded 1.27 mhn due, in part, to inclement weather conditions during time of sampling. Anopheles litoralis host seeking behavior occurred throughout the evening (06:00 PM - 06:00 AM) with peak biting between 10:00 PM and 04:00 AM. This species exhibited stronger zoophilic behavior based on comparison of HLC and BBT data. HLC showed a slightly greater exophagic (outdoor) behavior (1.4:1 ratio). During the July collection, an older adult population was present (75% parous) compared to the lower numbers of An. litoralis dissected in November (25% parous). Albeit a small sample size (n=19), 10.5% of An. litoralis dissected contained midgut oocysts of Plasmodium. Daytime adult resting harborages included biotic and abiotic sites in and around partially shaded, brackish water habitats where immature stages were common. Anopheles litoralis was found susceptible to pirimiphos-methyl and four different synthetic pyrethroids. This survey provides further epidemiological evidence of the importance of An. litoralis in malaria transmission on Bongao Island, and presumably throughout much of the Sulu Archipelago in the southern Philippines. Published observations of this species remain very limited and further investigations on the bionomics and epidemiological importance of this species are needed. Both ecological and human factors in malaria transmission are presented with implications for improved control of An. litoralis and prevention of infection.

Active case detection for malaria elimination: a survey among Asia Pacific countries.

BACKGROUND: Moving from malaria control to elimination requires national malaria control programmes to implement strategies to detect both symptomatic and asymptomatic cases in the community. In order to do this, malaria elimination programmes follow up malaria cases reported by health facilities to carry out case investigations that will determine the origin of the infection, whether it has been imported or is due to local malaria transmission. If necessary, the malaria programme will also carry out active surveillance to find additional malaria cases in the locality to prevent further transmission. To understand current practices and share information on malaria elimination strategies, a survey specifically addressing country policies on case investigation and reactive case detection was carried out among fourteen countries of the Asia Pacific Malaria Elimination Network (APMEN). METHODS: A questionnaire was distributed to the malaria control programme managers amongst 14 countries in the Asia Pacific who have national or sub-national malaria elimination goals. RESULTS: Results indicate that there are a wide variety of case investigation and active case detection activities employed by the 13 countries that responded to the survey. All respondents report conducting case investigation as part of surveillance activities. More than half of these countries conduct investigations for each case. Over half aim to accomplish the investigation within one to two days of a case report. Programmes collect a broad array of demographic data during investigation procedures and definitions for imported cases are varied across respondents. Some countries report intra-national (from a different province or district) importation while others report only international importation (from a different country). Reactive case detection in respondent countries is defined as screening households within a pre-determined radius in order to identify other locally acquired infections, whether symptomatic or asymptomatic. Respondents report that reactive case detection can be triggered in different ways, in some cases with only a single case report and in others if a defined threshold of multiple cases occurs. The spatial range of screening conducted varies from a certain number of households to an entire administrative unit (e g, village). Some countries target symptomatic people whereas others target all people in order to detect asymptomatic infections. The majority of respondent programmes collect a range of information from those screened for malaria, similar to the range of information collected during case investigation. CONCLUSION: Case investigation and reactive case detection are implemented in the malaria elimination programmes in the Asia Pacific, however practices vary widely from country to country. There is little evidence available to support countries in deciding which methods to maintain, change or adopt for improved effectiveness and efficiency. The development and use of common evaluation metrics for these activities will allow malaria programmes to assess performance and results of resource-intensive surveillance measures and may benefit other countries that are considering implementing these activities.

Determinants of malaria program expenditures during elimination: case study evidence from select provinces in the Philippines.

...Even though eliminating malaria from the endemic margins is a part of the Global Malaria Action Plan, little guidance exists on what resources are needed to transition from controlling malaria to eliminating it. Using Philippines as an example, this study aimed to (1) estimate the financial resources used by sub-national malaria programs in different phases during elimination and (2) understand how different environmental and organizational factors may influence expenditure levels and spending proportions. The Philippines provides an opportunity to study variations in sub-national programs because its epidemiological and ecological diversity, devolved health system, and progressive elimination strategy all allow greater flexibility for lower-level governments to direct activities, but also create challenges for coordination and resource mobilization. Through key informant interviews and archival record retrieval in four selected provinces chosen based on eco-epidemiological variation, expenditures associated with provincial malaria programs were collected for selected years (mid-1990s to 2010). Results show that expenditures per person at risk per year decrease as programs progress from a state of controlled low-endemic malaria to elimination to prevention of reintroduction regardless of whether elimination was deliberately planned. However, wide variation across provinces were found: expenditures were generally higher if mainly financed with donor grants, but were moderated by the level of economic development, the level of malaria transmission and receptivity, and the capacity of program staff. Across all provinces, strong leadership appears to be a necessary condition for maintaining progress and is vital in controlling outbreaks. While sampled provinces and years may not be representative of other sub-national malaria programs, these findings suggest that the marginal yearly cost declines with each phase during elimination.

Malaria elimination gaining ground in the Asia Pacific.

Countries in the Asia Pacific region are making substantial progress toward eliminating malaria, but their success stories are rarely heard by a global audience. "Malaria 2012: Saving Lives in the Asia-Pacific," a conference hosted by the Australian Government in Sydney, Australia from October 31 to November 2, 2012, will provide a unique opportunity to showcase the region's work in driving down malaria transmission. One of the features of Malaria 2012 will be the Asia Pacific Malaria Elimination Network (APMEN), which has focused on harnessing the collective experiences of 13 countries through regional political and technical collaboration since its inception in 2009. Run by country partners, APMEN unites a range of partners - from national malaria programmes and academic institutions to global and regional policymaking bodies - to support each country's malaria elimination goals through knowledge sharing, capacity building, operational research and advocacy.

A national baseline prevalence survey of schistosomiasis in the Philippines using stratified two-step systematic cluster sampling design.

For the first time in the country, a national baseline prevalence survey using a well-defined sampling design such as a stratified two-step systematic cluster sampling was conducted in 2005 to 2008. The purpose of the survey was to stratify the provinces according to prevalence of schistosomiasis such as high, moderate, and low prevalence which in turn would be used as basis for the intervention program to be implemented. The national survey was divided into four phases. Results of the first two phases conducted in Mindanao and the Visayas were published in 2008. Data from the last two phases showed three provinces with prevalence rates higher than endemic provinces surveyed in the first two phases thus changing the overall ranking of endemic provinces at the national level. Age and sex distribution of schistosomiasis remained the same in Luzon and Maguindanao. Soil-transmitted and food-borne helminthes were also recorded in these surveys. This paper deals with the results of the last 2 phases done in Luzon and Maguindanao and integrates all four phases in the discussion.

Prevalence survey of schistosomiasis in Mindanao and the Visayas, The Philippines.

The first two phases of a national prevalence survey of schistosomiasis in The Philippines were completed in Mindanao in 2005 and the Visayas in the first quarter of 2007. The design was a stratified two-step systematic cluster sampling, with two Kato-Katz thick smears examined from each participant. In Mindanao, a total of 22 provinces spread in six regions were covered by the survey with five barangays (equivalent to a village) per province for a total of 110 barangays. The response rate was 70.9% with a total of 21,390 individuals examined. The province of Maguindanao, a known endemic area for schistosomiasis japonica, failed to take part in the survey. In the Visayas, 10 out of 11 provinces, spread out in three regions, participated in the survey. There were 6321 respondents for an overall participation rate of 32.2%. Mindanao showed a wider coverage of the disease than the Visayas (60% versus 45%). By region, Caraga or Region 13 ranked first in Mindanao and Region 8 in the Visayas. By province, Agusan del Sur is first on the list, followed by Northern Samar and then Eastern Samar. Overall, the prevalence rate among males is higher than that of females suggesting the occupational hazard of farming and fishing among the males. The higher exposure among farmers and fishermen is also borne out by the age distribution of the disease. Prevalence remains consistently high among the adults compared with the younger age groups. The survey also covered other helminth infections that can be detected in a stool survey, notably soil-transmitted helminthes and food-borne trematodes.