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Background: In 2015 alone there were an estimated 214 million new cases of malaria across the globe and 438,000 deaths were reported. Although indigenous malaria has not been reported in Sri Lanka since 2012, to date 247 imported cases of malaria have been identified. Knowledge of the locations, behaviour and vectorial capacity of potential malarial vectors is therefore needed to prevent future outbreaks. Attention is now being focused on some previously ignored habitats., Methods: Active and abandoned granite and clay quarry pits, located in wet and intermediate zones, and agro wells located in the dry zone of Sri Lanka were mapped and sampled for 1 year, as potential mosquito breeding sites. Species composition and spatio-temporal variation in both malarial and other mosquito larvae were recorded., Results: A total of 18 species of mosquito larvae were identified. Other than Anopheles culicifacies, the primary malaria vector, five species of potential malaria vectors (Anopheles vagus, Anopheles varuna, Anopheles nigerrimus, Anopheles peditaeniatus and Anopheles barbirostris) were found in all three aquatic systems. Additionally, Anopheles annularis was found in granite quarries and Anopheles subpictus and Anopheles pallidus in both types of quarry, but only during the initial sampling. Apart from potential malaria vectors, mosquito larvae such as Anopheles jamesii, Culex tritaeniorhynchus, Culex infula and Culex malayi were found in all three habitats at least once during the sampling period. Apart from potential malaria vectors and other mosquito larvae common to all three aquatic systems, Culex gelidus, Culex mimulus and Culex pseudo vishnui were detected in agro wells. Culex gelidus was also detected in granite quarry pits. Culex mimulus, Culex lutzia and Culex fuscocephala were detected in clay quarry pits. Accordingly, a total of 14, 13 and 15 mosquito species were identified in agro wells, granite and clay quarry pits, respectively., Conclusions: Although zero occurrence of indigenous malaria has been achieved in Sri Lanka, the current study emphasizes the potential for future epidemics. The presence of native flora and fauna in abandoned granite and clay quarry pits and the need to extract drinking water from agro wells demand bio-sensitive control methods in these three aquatic systems.

Background: A Sinhalese version of a validated, disease-specific patient-reported heart disease health related quality of life instrument is lacking. The purpose of this study was to validate the interviewer-administered Sinhalese version of the MacNew Heart Disease Health-related Quality of Life Questionnaire (MacNew) in patients with clinically diagnosed stable angina., Methods: The Sinhalese translation of the MacNew was carried using standard forward- backward translation technique. In this validation study, the MacNew was administered to 200 patients with stable angina. Reliability was assessed by internal consistency and test-retest reliability. Construct validity was explored by exploratory factor analysis using principal component analysis and confirmed by confirmatory factor analysis using the robust maximum likelihood method and known group comparison. The correlation between compatible domain scores of MacNew and the World Health Organization's quality of life -brief questionnaire was used to assess concurrent validity., Results: The original 3-factor model (Physical, Emotional and Social) of the MacNew with cross-loadings was confirmed: principal component analysis with 53.42 % of the explained variance and confirmatory factor analysis with adequate fit for each of the three model fit criteria considered [root mean square error of approximation = 0.044 (90 % CI = 0.031 to 0.056); comparative fit index = 0.99; χ(2)/df = 1.39]. Internal consistency of the MacNew was acceptable with Cronbach's α of 0.92 on the Global scale and on the domain scales ranging from 0.85-0.91. Test-retest reliability was also found to be satisfactory with intraclass correlation coefficients of >0.9 for total and domain scores. A satisfactory level of concurrent validity was demonstrated with statistically significant correlations between compatible domain scores of MacNew and the World Health Organization's quality of life questionnaire (Pearson correlation ranging from 0.36-0.79)., Conclusions: The interviewer-administered Sinhalese MacNew is a valid and reliable patient-reported outcome measure to assess disease specific health-related quality of life among Sinhalese patients with stable angina.

Background: Areas with dynamic population movements are likely to be associated with higher levels of drug-resistant malaria. Myanmar Artemisinin Resistance Containment (MARC) Project has been launching since 2012. One of its components includes enhancing strategic approaches for mobile/migrant populations. We aimed to ascertain the estimated population of mobile migrant workers and their families in terms of stability in work setting in townships classified as tier II (areas with significant inflows of people from areas with credible evidence of artemisinin resistance) for Artemisinin resistance; to identify knowledge, attitudes and practices related to prevention and control of malaria and to recommend cost-effective strategies in planning for prevention and control of malaria., Methods: A prospective cross-sectional study conducted between June to December 2013 that covered 1,899 migrant groups from 16 tier II townships of Bago Region, and Kayin and Kayah States. Trained data collectors used a pre-tested and subsequently modified questionnaire and interviewed 2,381 respondents. Data of migrant groups were analyzed and compared by category depending upon the stability of their work setting., Results: The estimated population of the 1,899 migrant groups categorized into three on the nature of their work setting was 56,030. Bago region was the commonest reported source of origin of migrant groups as well as their transit. Malaria volunteers were mostly within the reach of category 1 migrant groups (43/66, 65.2 %). Less stable migrant groups in category 3 had limited access to malaria information (14.7 %) and malaria care providers (22.1 %), low level of awareness and use of long-lasting insecticide-treated nets (46.6 and 38.8 %). Also, they had poor knowledge on malaria prevention on confirming suspected malaria and on using artemisinin combined therapy (ACT). Within two weeks prior to the survey, only 16.5 % of respondents in all categories combined reported acute undifferentiated fever., Discussion and Conclusions: Mobility dynamics of migrant groups was complex and increased their vulnerability to malaria. This phenomenon was accentuated in less stable areas. Even though migrant workers were familiar with rapid diagnostic tests for malaria, ACT still needed wide recognition to improve practices supportive of MARC including the use of appropriate personal protection. High mobility calls for re-designation of tier II townships to optimize ACT resistance containment.

Asymptomatic infection is an important obstacle for controlling disease in countries where malaria is endemic. Because asymptomatic carriers do not seek treatment for their infections, they can have high levels of gametocytes and constitute a reservoir available for new infection. We employed a sample pooling/PCR-based molecular detection strategy for screening malaria infection in residents from areas of Myanmar where malaria is endemic. Blood samples (n = 1,552) were collected from residents in three areas of malaria endemicity (Kayin State, Bago, and Tanintharyi regions) of Myanmar. Two nested PCR and real-time PCR assays showed that asymptomatic infection was detected in about 1.0% to 9.4% of residents from the surveyed areas. The sensitivities of the two nested PCR and real-time PCR techniques were higher than that of microscopy examination (sensitivity, 100% versus 26.4%; kappa values, 0.2 to 0.5). Among the three regions, parasite-positive samples were highly detected in subjects from the Bago and Tanintharyi regions. Active surveillance of residents from regions of intense malaria transmission would reduce the risk of morbidity and mitigate transmission to the population in these areas of endemicity. Our data demonstrate that PCR-based molecular techniques are more efficient than microscopy for nationwide surveillance of malaria in countries where malaria is endemic., (Copyright © 2014, American Society for Microbiology. All Rights Reserved.)

Malaria is one of the most important tropical diseases that has caused devastation throughout the history of mankind. Malaria eradication programmes in the past have had many positive effects but failed to wipe out malaria from most tropical countries, including Sri Lanka. Encouraged by the impressive levels of reduction in malaria case numbers during the past decade, Sri Lanka has launched a programme to eliminate malaria by year 2014. This article reviews the historical milestones associated with the malaria eradication programme that failed subsequently and the events that led to the launch of the ongoing malaria elimination plans at national-level and its strategies that are operational across the entire country. The existing gaps in knowledge are also discussed together with the priority areas for research to fill in these gaps that are posing as challenges to the envisaged goal of wiping out malaria from this island nation.

Background: Plasmodium vivax infections are an important contributor to the malaria burden worldwide. The World Health Organization recommends a 14-day course of primaquine (0.25 mg/kg/day, giving an adult dose of 15 mg/day) to eradicate the liver stage of the parasite and prevent relapse of the disease. Many people find a 14-day primaquine regimen difficult to complete, and there is a potential risk of haemolytic anaemia in people with glucose-6-phosphate-dehydrogenase enzyme (G6PD) deficiency. This review evaluates primaquine in P. vivax, particularly alternatives to the standard 14-day course., Objectives: To compare alternative primaquine regimens to the recommended 14-day regimen for preventing relapses (radical cure) in people with P. vivax malaria treated for blood stage infection with chloroquine. We also summarize trials comparing primaquine to no primaquine that led to the recommendation for the 14-day regimen., Search Methods: We searched the Cochrane Infectious Diseases Group's Specialized Register, CENTRAL (The Cochrane Library), MEDLINE, EMBASE and LILACS up to 8 October 2013. We checked conference proceedings, trial registries and reference lists and contacted researchers and pharmaceutical companies for eligible studies., Selection Criteria: Randomized controlled trials (RCTs) and quasi-RCTs comparing various primaquine dosing regimens with the standard primaquine regimen (15 mg/day for 14 days), or with no primaquine, in people with vivax malaria treated for blood stage infection with chloroquine., Data Collection and Analysis: We independently assessed trial eligibility, trial quality, and extracted data. We calculated risk ratios (RR) with 95% confidence intervals (CI) for dichotomous data, and used the random-effects model in meta-analyses if there was significant heterogeneity. We assessed the overall quality of the evidence using the GRADE approach., Main Results: We included 15 trials (two cluster-RCTs) of 4377 adult and child participants. Most trials excluded people with G6PD deficiency. Trials compared various regimens of primaquine with the standard primaquine regimen, or with placebo or no treatment. All trials treated blood stage infection with chloroquine. Alternative primaquine regimens compared to 14-day primaquineRelapse rates were higher over six months with the five-day primaquine regimen than the standard 14-day regimen (RR 10.05, 95% CI 2.82 to 35.86; two trials, 186 participants, moderate quality evidence). Similarly, relapse over six months was higher with three days of primaquine than the standard 14-day regimen (RR 3.18, 95% CI 2.1 to 4.81; two trials, 262 participants, moderate quality evidence; six months follow-up); and with primaquine for seven days followed up over two months, compared to 14-day primaquine (RR 2.24, 95% CI 1.24 to 4.03; one trial, 126 participants, low quality evidence).Relapse with once-weekly supervised primaquine for eight weeks was little different over nine months follow-up compared to 14-day self-administered primaquine in one small study (RR 2.97, 95% CI 0.34 to 25.87; one trial, 129 participants, very low quality evidence). Primaquine regimens compared to no primaquineThe number of people that relapsed was similar between people given five days of primaquine or given placebo or no primaquine (four trials, 2213 participants, high quality evidence; follow-up six to 15 months); but lower with 14 days of primaquine (RR 0.6; 95% CI 0.48 to 0.75; ten trials, 1740 participants, high quality evidence; follow-up seven weeks to 15 months).No serious adverse events were reported. Treatment-limiting adverse events were rare and non-serious adverse events were mild and transient. Trial authors reported that people tolerated the drugs.We did not find trials comparing higher dose primaquine regimens (0.5 mg/kg/day or more) for five days or more with the 14-day regimen., Authors' Conclusions: The analysis confirms the current World Health Organization recommendation for 14-day primaquine (15 mg/day) to prevent relapse of vivax malaria. Shorter primaquine regimens at the same daily dose are associated with higher relapse rates. The comparative effects with weekly primaquine are promising, but require further trials to establish equivalence or non-inferiority compared to the 14-day regimen in high malaria transmission settings.

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.

Background: With Sri Lanka aiming towards malaria elimination by 2015, the National Anti Malaria Campaign has stressed on the importance of identification of the species of Plasmodium either by examination of stained blood smears for malaria parasites or by Rapid Diagnostic Tests for malaria antigens before the initiation of treatment. This study aims at confirmation of the accuracy of clinical and/or microscopical malaria diagnosis using serology., Materials and Methods: Study population comprised 51 individuals diagnosed with malaria either microscopically or clinically during the first half of 2011. ELISA for detection of the two significant blood antigens (AMA-1 and MSP1-19) was carried out in these individuals, 14-28 days after being diagnosed as being positive for malaria microscopically., Results: ELISA confirmed the microscopic diagnosis in all 47 of the patients including two mixed infections which flagged positive for both parasite antigens. However, four individuals diagnosed clinically as being positive for P. vivax by Health Care Providers were negative for malaria antibodies by ELISA., Conclusions: With 175 cases of malaria reported in 2011, a formidable challenge exists to diagnose malaria positive blood smears due to the large number of negative blood smears being seen daily. After routine cross checking of positive slides, it is heartening to note that there were no false positives detected through serological assays amongst patients who were diagnosed as malaria positive by microscopy. Presumptive treatment of febrile patients with anti-malarials can lead to waste of resources and adversely impact the condition of the patient if the fever is not due to malaria.

Objective: To discuss epidemiological aspects of imported malaria and the potential impact of imported malaria cases reported in Sri Lanka 2008-2011 in terms of a possible resurgence of the disease., Methods: The national malaria database was used to assess details regarding country where the infection was possibly acquired, species of Plasmodium, number of days lapsed between disembarkation in Sri Lanka and diagnosis, compliance with national treatment guidelines including percentage of patients followed up as per the national guidelines., Results: After the strengthening of malaria surveillance, during the 4-year period, 152 imported malaria cases were recorded: an increase of 176% in the number of cases. Most of the imported malaria infections were acquired by Sri Lankan Nationals mainly from South Asia, especially India. Plasmodium vivax accounted for 64% of the infections. Approximately 50% of the cases were diagnosed in the Western Province. The average period from disembarkation in Sri Lanka to malaria diagnosis was 3.6 days. Patients were managed and treated according to the national guidelines. 82% of the patients were followed up for 28 days to ensure parasite clearance., Conclusions: There is a possible increasing risk of re-introduction of malaria to the country from imported cases. Enhanced surveillance activities and the increase in international travel have contributed to an increase in recorded case numbers. There is a need to further strengthen surveillance, especially for monitoring and timely addressing of imported malaria, if the country is to prevent the re-establishment of transmission within. The importance of having an efficient response mechanism to deal with imported malaria is also highlighted., (© 2013 John Wiley & Sons Ltd.)

Background: The number of malaria cases among irregular migrants returning to Sri Lanka has not been investigated., Methods: In the first 6 months of 2012 we screened 287 irregular migrants returning from seven West African nations to Sri Lanka for malaria to ascertain the risk of infection during migration., Results: Four men were diagnosed as having malaria: three with Plasmodium falciparum had travelled to Togo and one with P. vivax had travelled to Guinea. The risk of contracting malaria was 14 cases per 1000., Conclusion: Facilitating a safe return with selective screening for at-risk inbound migrants flows is desirable as Sri Lanka advances towards its goal of malaria elimination.

Background: Malaria-related knowledge, preventative methods and treatment-seeking behaviours were investigated in a post-conflict district of Sri Lanka in order to guide the development of components of malaria interventions and to support future programme evaluation., Methods: A structured questionnaire was used to collect data from a random sample of 300 households in four Divisional Secretariat Divisions (DSD) of the district where internally displaced populations were being resettled after a 30-year civil war., Results: The surveyed community had a good overall level of knowledge of malaria. There was high bednet ownership (94.0%), although only 48.0% of households in the study had long-lasting insecticide-treated nets (LLIN). Most respondents reported rapid treatment-seeking behaviour (71.0%) and easy access to malaria diagnostic facilities (67.0%). The Tamil population living in Manthai West and Madhu DSDs who were displaced to refugee camps had better malaria-related knowledge and practices, probably due to the malaria control activities focused on these camps by the government., Conclusions: Although knowledge and practices regarding malaria amongst resettled populations in Mannar District were high, continued malaria surveillance, case management, vector control including distribution of LLINs, education and information campaigns are important not only amongst the communities affected by the conflict but the entire district.

Background. We describe an irregular migrant who returned to Sri Lanka after a failed people smuggling operation from West Africa. Results. On-arrival screening by Anti-Malaria Campaign (AMC) officers using a rapid diagnostic test (RDT) (CareStart Malaria HRP2/PLDH) indicated a negative result. On day 3 after arrival, he presented with fever and chills but was managed as dengue (which is hyperendemic in Sri Lanka). Only on day 7, diagnosis of Plasmodium falciparum malaria was made by microcopy and CareStart RDT. The initially negative RDT was ascribed to a low parasite density. Irregular migration may be an unrecognized source of malaria reintroduction. Despite some limitations in detection, RDTs form an important point-of-entry assessment. As a consequence of this case, the AMC is now focused on repeat testing and close monitoring of all irregular migrants from malaria-endemic zones. Conclusion. The present case study highlights the effective collaboration and coordination between inter-governmental agencies such as IOM and the Ministry of Health towards the goals of malaria elimination in Sri Lanka.

Background: Bhutan has achieved a major reduction in malaria incidence amid multiple challenges. This case study seeks to characterize the Bhutan malaria control programme over the last 10 years., Methods: A review of the malaria epidemiology, control strategies, and elimination strategies employed in Bhutan was carried out through a literature review of peer-reviewed and grey national and international literature with the addition of reviewing the surveillance and vector control records of the Bhutan Vector-Borne Disease Control Programme (VDCP). Data triangulation was used to identify trends in epidemiology and key strategies and interventions through analysis of the VDCP surveillance and programme records and the literature review. Enabling and challenging factors were identified through analysis of socio-economic and health indicators, corroborated through a review of national and international reports and peer-review articles., Findings: Confirmed malaria cases in Bhutan declined by 98.7% from 1994 to 2010. The majority of indigenous cases were due to Plasmodium vivax (59.9%) and adult males are most at-risk of malaria. Imported cases, or those in foreign nationals, varied over the years, reaching 21.8% of all confirmed cases in 2006. Strategies implemented by the VDCP are likely to be related to the decline in cases over the last 10 years. Access to malaria diagnosis in treatment was expanded throughout the country and evidence-based case management, including the introduction of artemisinin-based combination therapy (ACT) for P. falciparum, increasing coverage of high risk areas with Indoor Residual Spraying, insecticide-treated bed nets, and long-lasting insecticidal nets are likely to have contributed to the decline alongside enabling factors such as economic development and increasing access to health services., Conclusion: Bhutan has made significant strides towards elimination and has adopted a goal of national elimination. A major challenge in the future will be prevention and management of imported malaria infections from neighbouring Indian states. Bhutan plans to implement screening at border points to prevent importation of malaria and to targeted prevention and surveillance efforts towards at-risk Bhutanese and migrant workers in construction sites.

Background: Sri Lanka has a long history of malaria control, and over the past decade has had dramatic declines in cases amid a national conflict. A case study of Sri Lanka's malaria programme was conducted to characterize the programme and explain recent progress., Methods: The case study employed qualitative and quantitative methods. Data were collected from published and grey literature, district-level and national records, and thirty-three key informant interviews. Expenditures in two districts for two years--2004 and 2009--were compiled., Findings: Malaria incidence in Sri Lanka has declined by 99.9% since 1999. During this time, there were increases in the proportion of malaria infections due to Plasmodium vivax, and the proportion of infections occurring in adult males. Indoor residual spraying and distribution of long-lasting insecticide-treated nets have likely contributed to the low transmission. Entomological surveillance was maintained. A strong passive case detection system captures infections and active case detection was introduced. When comparing conflict and non-conflict districts, vector control and surveillance measures were maintained in conflict areas, often with higher coverage reported in conflict districts. One of two districts in the study reported a 48% decline in malaria programme expenditure per person at risk from 2004 to 2009. The other district had stable malaria spending., Conclusions/significance: Malaria is now at low levels in Sri Lanka--124 indigenous cases were found in 2011. The majority of infections occur in adult males and are due to P. vivax. Evidence-driven policy and an ability to adapt to new circumstances contributed to this decline. Malaria interventions were maintained in the conflict districts despite an ongoing war. Sri Lanka has set a goal of eliminating malaria by the end of 2014. Early identification and treatment of infections, especially imported ones, together with effective surveillance and response, will be critical to achieving this goal.

Diagnostic confusion may occur between dengue and malaria when febrile patients with thrombocytopenia return from travel to previous malaria endemic areas. Laboratory tests should include blood smear examination for malaria parasites even though current malaria endemicity in Sri Lanka is low., (© 2011 International Society of Travel Medicine.)

Genetic diversity and population structure of Plasmodium vivax parasites can predict the origin and spread of novel variants within a population enabling population specific malaria control measures. We analyzed the genetic diversity and population structure of 425 P. vivax isolates from Sri Lanka, Myanmar, and Ethiopia using 12 trinucleotide and tetranucleotide microsatellite markers. All three parasite populations were highly polymorphic with 3-44 alleles per locus. Approximately 65% were multiple-clone infections. Mean genetic diversity (H(E)) was 0.7517 in Ethiopia, 0.8450 in Myanmar, and 0.8610 in Sri Lanka. Significant linkage disequilibrium was maintained. Population structure showed two clusters (Asian and African) according to geography and ancestry. Strong clustering of outbreak isolates from Sri Lanka and Ethiopia was observed. Predictive power of ancestry using two-thirds of the isolates as a model identified 78.2% of isolates accurately as being African or Asian. Microsatellite analysis is a useful tool for mapping short-term outbreaks of malaria and for predicting ancestry.

Sleeping arrangements under long-lasting impregnated nets (LLIN) were recorded in 2467 households during the low malaria transmission season (May-June 2007) and the same families were followed up during the high malaria transmission season (December 2007-January 2008) in two malaria-endemic areas of Sri Lanka. Approximately 800 households each from the three main ethnic groups were studied. The number of families lost to follow-up was 68. A significant increase was seen in the proportion of households using LLINs the previous night during the high transmission season (96%) compared with the low transmission season (90%) (P< or =0.001 for all three ethnic groups). When sleeping arrangements of the entire population were considered, priority to sleep under the LLIN was given to children under 5 years during both seasons. The percentage of children under five who slept under a LLIN increased from 75% during the low transmission season to 90% during the high transmission season. Utilisation of LLINs by pregnant women was low; only approximately 45% of pregnant women reported sleeping under a LLIN during both seasons. The study suggests the possible need for re-focusing of health education messages regarding the importance of LLIN use among pregnant women.

As the goal of malaria elimination from Sri Lanka is currently being pursued, this study was planned to determine the prevalence of asymptomatic malaria infections. Five health areas in Trincomalee and Kurunegala districts that reported high prevalence in the recent past were purposively selected. The smallest administrative units (GN divisions) having high malaria risk within each area were identified. From these divisions, 20% of the population was randomly selected for blood smear examination and in a 50% sub-sample polymerase chain reaction (PCR) assay was performed. A population of 3,730 from 13 GN divisions was sampled. Thick and thin Giemsa-stained blood smears were negative for malaria parasites. The PCR carried out in 50% of the study sample was also negative for malaria parasites. The findings illustrate the absence of asymptomatic carriers in previously high transmission areas and it appears that achieving malaria elimination in Sri Lanka by 2015 is feasible.

The Anti Malaria Campaign distributed approximately 300,000 long-lasting impregnated nets (LLINs) to malaria-endemic areas in Sri Lanka during the years 2005 to 2007. We conducted a community-based cross-sectional survey among 2467 households distributed among the three major ethnic groups of Sri Lanka to study the perceptions and practices with regard to the use of LLINs in order to improve their use. In a majority of households the number of LLINs available was not sufficient for the number of people, although there was a small percentage of households that had excess nets. The information and advice given at the time of distribution regarding use of the nets differed amongst the three groups and was not consistent. Dissemination of this knowledge within the family was not observed. A relationship between knowledge regarding LLINs and reported practices on washing and drying of LLINs was found. It was noted that net shape may influence net use, with cone shaped nets being more popular. Efforts to increase knowledge on LLINs using behaviour change communication techniques would have more effectively contributed to achieve planned outcomes. Proper use of LLINs will undoubtedly contribute to further reduction of malaria in Sri Lanka.

Background: El Niño events were suggested as a potential predictor for malaria epidemics in Sri Lanka based on the coincidence of nine out of 16 epidemics with El Niño events from 1870 to 1945. Here the potential for the use of El Niño predictions to anticipate epidemics was examined using enhanced climatic and epidemiological data from 1870 to 2000., Methods: The epidemics start years were identified by the National Malaria Control Programme and verified against epidemiological records for consistency. Monthly average rainfall climatologies were estimated for epidemic and non-epidemic years; as well El Niño, Neutral and La Niña climatic phases. The relationship between El Niño indices and epidemics was examined to identify 'epochs' of consistent association. The statistical significance of the association between El Niño and epidemics for different epochs was characterized. The changes in the rainfall-El Niño relationships over the decade were examined using running windowed correlations. The anomalies in rainfall climatology during El Niño events for different epochs were compared., Results: The relationship between El Niño and epidemics from 1870 to 1927 was confirmed. The anomalies in monthly average rainfall during El Niño events resembled the anomalies in monthly average rainfall during epidemics during this period. However, the relationship between El Niño and epidemics broke down from 1928 to 1980. Of the three epidemics in these six decades, only one coincided with an El Niño. Not only did this relationship breakdown but epidemics were more likely to occur in periods with a La Niña tendency. After 1980, three of four epidemics coincided with El Niño., Conclusion: The breakdown of the association between El Niño and epidemics after 1928 is likely due to an epochal change in the El Niño-rainfall relationship in Sri Lanka around the 1930's. It is unlikely that this breakdown is due to the insecticide spraying programme that began in 1945 since the breakdown started in 1928. Nor does it explain the occurrence of epidemics during La Niña phase from 1928 to 1980. Although there has been renewed coincidence with El Niño after 1980, this record is too short for establishing a reliable relationship.

Background: Malaria in Sri Lanka is unstable and fluctuates in intensity both spatially and temporally. Although the case counts are dwindling at present, given the past history of resurgence of outbreaks despite effective control measures, the control programmes have to stay prepared. The availability of long time series of monitored/diagnosed malaria cases allows for the study of forecasting models, with an aim to developing a forecasting system which could assist in the efficient allocation of resources for malaria control., Methods: Exponentially weighted moving average models, autoregressive integrated moving average (ARIMA) models with seasonal components, and seasonal multiplicative autoregressive integrated moving average (SARIMA) models were compared on monthly time series of district malaria cases for their ability to predict the number of malaria cases one to four months ahead. The addition of covariates such as the number of malaria cases in neighbouring districts or rainfall were assessed for their ability to improve prediction of selected (seasonal) ARIMA models., Results: The best model for forecasting and the forecasting error varied strongly among the districts. The addition of rainfall as a covariate improved prediction of selected (seasonal) ARIMA models modestly in some districts but worsened prediction in other districts. Improvement by adding rainfall was more frequent at larger forecasting horizons., Conclusion: Heterogeneity of patterns of malaria in Sri Lanka requires regionally specific prediction models. Prediction error was large at a minimum of 22% (for one of the districts) for one month ahead predictions. The modest improvement made in short term prediction by adding rainfall as a covariate to these prediction models may not be sufficient to merit investing in a forecasting system for which rainfall data are routinely processed.

Background: Rainfall data have potential use for malaria prediction. However, the relationship between rainfall and the number of malaria cases is indirect and complex., Methods: The statistical relationships between monthly malaria case count data series and monthly mean rainfall series (extracted from interpolated station data) over the period 1972 - 2005 in districts in Sri Lanka was explored in four analyses: cross-correlation; cross-correlation with pre-whitening; inter-annual; and seasonal inter-annual regression., Results: For most districts, strong positive correlations were found for malaria time series lagging zero to three months behind rainfall, and negative correlations were found for malaria time series lagging four to nine months behind rainfall. However, analysis with pre-whitening showed that most of these correlations were spurious. Only for a few districts, weak positive (at lags zero and one) or weak negative (at lags two to six) correlations were found in pre-whitened series. Inter-annual analysis showed strong negative correlations between malaria and rainfall for a group of districts in the centre-west of the country. Seasonal inter-annual analysis showed that the effect of rainfall on malaria varied according to the season and geography., Conclusion: Seasonally varying effects of rainfall on malaria case counts may explain weak overall cross-correlations found in pre-whitened series, and should be taken into account in malaria predictive models making use of rainfall as a covariate.

Background: Single nucleotide polymorphisms (SNPs) in the Plasmodium vivax dihydrofolate reductase (Pfdhfr) and dihydropteroate synthetase (Pvdhps) genes cause parasite resistance to the antifolate drug combination, sulphadoxine/pyrimethamine (SP). Monitoring these SNPs provide insights into the level of drug pressure caused by SP use and presumably other antifolate drugs. In Sri Lanka, chloroquine (CQ) with primaquine (PQ) and SP with PQ is used as first and second line treatment, respectively, against uncomplicated Plasmodium falciparum and/or P. vivax infections. CQ/PQ is still efficacious against P. vivax infections, thus SP is rarely used and it is assumed that the prevalence of SNPs related to P. vivax SP resistance is low. However, this has not been assessed in Sri Lanka as in most other parts of Asia. This study describes the prevalence and distribution of SNPs related to P. vivax SP resistance across Sri Lanka., Subjects and Methods: P. vivax-positive samples were collected from subjects presenting at government health facilities across nine of the major malaria endemic districts on the island. The samples were analysed for SNPs/haplotypes at codon 57, 58, 61 and 117 of the Pvdhfr gene and 383, 553 and 585 of the Pvdhps gene by applying PCR followed by a hybridization step using sequence specific oligonucleotide probes (SSOPs) in an ELISA format., Results: In the study period, the government of Sri Lanka recorded 2,149 P. vivax cases from the nine districts out of which, 454 (21.1%) blood samples were obtained. Pvdhfr haplotypes could be constructed for 373 of these. The FSTS wild-haplotype was represented in 257 samples (68.9%), the double mutant LRTS haplotype was the most frequently observed mutant (24.4%) while the triple mutation (LRTN) was only identified once. Except for two samples of the single mutated Pvdhps GAV haplotype, the remaining samples were wildtype. Geographical differences were apparent, notably a significantly higher frequency of mutant Pvdhfr haplotypes was observed in the Northern districts., Conclusion: Since SP is rarely used in Sri Lanka, the high frequency and diversity of Pvdhfr mutations was unexpected indicating the emergence of drug resistant parasites despite a low level of SP drug pressure.

Background: Plasmodium vivax infections contribute to a significant proportion of the malaria infections in many countries. Primaquine is the most widely used drug for treating the dormant liver stage. Different primaquine dosing regimens are in use., Objectives: To compare primaquine regimens for preventing relapses in people with P. vivax malaria., Search Strategy: In 2006, we searched the Cochrane Infectious Diseases Group's Specialized Register (January), CENTRAL (The Cochrane Library 2006, Issue 3), MEDLINE (October), EMBASE (January), LILACS (January). We also checked conference proceedings and reference lists, and contacted researchers, the World Health Organization (WHO), malaria mailing lists, and pharmaceutical companies., Selection Criteria: Randomized and quasi-randomized controlled trials comparing primaquine plus chloroquine with chloroquine alone, and the standard primaquine regimen (15 mg/day for 14 days) with other primaquine-containing regimens in people with vivax malaria., Data Collection and Analysis: All authors independently assessed trial eligibility and quality, and extracted data. We calculated odds ratios (OR) with 95% confidence intervals (CI) for dichotomous data, and used the random-effects model if there was significant heterogeneity., Main Results: Nine trials (3423 participants) met the inclusion criteria. Compared with chloroquine alone, five-day primaquine plus chloroquine was no better at preventing relapses (OR 1.04, 95% CI 0.64 to 1.69, random-effects model; 2104 participants; 3 trials), while 14-day primaquine plus chloroquine was significantly better (OR 0.24, 95% CI 0.12 to 0.45, random-effects model; 1071 participants, 6 trials). Limited data suggest the advantage for the 14-day primaquine regimen persisted for over six months (OR 0.41, 95% CI 0.29 to 0.60; 585 participants, 2 trials). Direct comparisons of the 14-day and five-day primaquine plus chloroquine regimens also confirm the superiority of the longer course (OR 13.33, 95% CI 3.45 to 51.44; 186 participants, 2 trials). Adverse effects were poorly reported, with three trials reporting skin rash, vertigo, headache, abdominal pain and/or nausea, and two trials reporting that primaquine was well tolerated., Authors' Conclusions: Primaquine (15 mg/kg/day for 14 days) plus chloroquine is more effective than chloroquine alone or primaquine (15 mg/kg for 5 days) plus chloroquine in preventing relapses of vivax malaria. Primaquine (five days) plus chloroquine appears no better than chloroquine. Countries should follow the WHO's recommendation for 14-day primaquine plus chloroquine regimen. Alternative regimens need to be evaluated in randomized controlled trials, which should also consider variations in regional P. vivax strains and the possibility of primaquine resistance, reinfection, and adherence in those who relapse.

One year ago, the authors of this article reported in this journal on the malaria situation in Sri Lanka prior to the tsunami that hit on 26 December 2004, and estimated the likelihood of a post-tsunami malaria outbreak to be low. Malaria incidence has decreased in 2005 as compared to 2004 in most districts, including the ones that were hit hardest by the tsunami. The malaria incidence (aggregated for the whole country) in 2005 followed the downward trend that started in 2000. However, surveillance was somewhat affected by the tsunami in some coastal areas and the actual incidence in these areas may have been higher than recorded, although there were no indications of this and it is unlikely to have affected the overall trend significantly. The focus of national and international post tsunami malaria control efforts was supply of antimalarials, distribution of impregnated mosquito nets and increased monitoring in the affected area. Internationally donated antimalarials were either redundant or did not comply with national drug policy, however, few seem to have entered circulation outside government control. Despite distribution of mosquito nets, still a large population is relatively exposed to mosquito bites due to inadequate housing. There were no indications of increased malaria vector abundance. Overall it is concluded that the tsunami has not negatively influenced the malaria situation in Sri Lanka.

The malaria situation in Sri Lanka worsened during the 1990s with the emergence and spread of resistance to the drugs and insecticides used for control. Chloroquine resistance has increased rapidly over this period, but adverse changes in malaria transmission are more closely associated with insecticide use rather than drug resistance. Insecticide susceptibility tests were routinely carried out in key anopheline vectors across the country for more than a decade. These sentinel data were combined with data collected by other research programmes and used to map the spatial and temporal trends of insecticide resistance in the main vectors, Anopheles culicifacies and A. subpictus, and to examine the relationship between insecticide resistance, changes in national spraying regimens and malaria prevalence. Both species had widespread resistance to malathion, the insecticide of choice in the early 1990s. Both species were initially susceptible to the organophosphate and pyrethroid insecticides used operationally from 1993, but some resistance has now been selected. The levels of malathion and fenitrothion resistance in A. subpictus were higher in some ecological regions than others, which may be related to the distribution of sibling species, agricultural pesticide exposure and/or environmental factors. The study highlights that the emergence and spread of insecticide resistance is a constant threat and that active surveillance systems are vital in identifying key vectors and evidence of resistance.

Background: Following the tsunami, a detailed overview of the area specific transmission levels is essential in assessing the risk of malaria in Sri Lanka. Recent information on vector insecticide resistance, parasite drug resistance, and insights into the national policy for malaria diagnosis and treatment are important in assisting national and international agencies in their control efforts., Methods: Monthly records over the period January 1995-October 2004 of confirmed malaria cases were used to perform an analysis of malaria distribution at district spatial resolution. Also, a focused review of published reports and routinely collected information was performed., Results: The incidence of malaria was only 1 case per thousand population in the 10 months leading up to the disaster, in the districts with the highest transmission., Conclusion: Although relocated people may be more exposed to mosquito bites, and their capacity to handle diseases affected, the environmental changes caused by the tsunami are unlikely to enhance breeding of the principal vector, and, given the present low parasite reservoir, the likelihood of a malaria outbreak is low. However, close monitoring of the situation is necessary, especially as December-February is normally the peak transmission season. Despite some losses, the Sri Lanka public health system is capable of dealing with the possible threat of a malaria outbreak after the tsunami. The influx of foreign medical assistance, drugs, and insecticides may interfere with malaria surveillance, and the long term malaria control strategy of Sri Lanka, if not in accordance with government policy.