Malaria in India: challenges and opportunities

Chloroquine efficacy studies confirm drug susceptibility of Plasmodium vivax in Chennai, India

Background

Assessing the Plasmodium vivax burden in India is complicated by the potential threat of an emerging chloroquine (CQ) resistant parasite population from neighbouring countries in Southeast Asia. Chennai, the capital of Tamil Nadu and an urban setting for P. vivax in southern India, was selected as a sentinel site for investigating CQ efficacy and sensitivity in vivax malaria.

Methods

CQ efficacy was evaluated with a 28-day in vivo therapeutic study, while CQ sensitivity was measured with an in vitro drug susceptibility assay. In both studies, isolates also underwent molecular genotyping to investigate correlations between parasite diversity and drug susceptibility to CQ. Molecular genotyping included sequencing a 604 base pair (bp) fragment of the P. vivax multidrug resistant gene-1 (Pvmdr1) for single nucleotide polymorphisms (SNPs) and also the amplification of eight microsatellite (MS) loci located across the genome on eight different chromosomes.

Results

In the 28-day in vivo study (N=125), all subjects were aparasitaemic by Day 14. Passive case surveillance continuing beyond Day 28 in 22 subjects exposed 17 recurrent infections, which ranged from 44 to 148 days post-enrollment. Pvmdr1 sequencing of these recurrent infections revealed that 93.3% had identical mutant haplotypes (958M/Y976/1076L) to their baseline Day 0 infection. MS genotyping further revealed that nine infection pairs were related with ≥75% haplotype similarity (same allele at six or more loci). To test the impact of this mutation on CQ efficacy, an in vitro drug assay (N=68) was performed. No correlation between IC₅₀ values and the percentage of ring-stage parasites prior to culture was observed (r_sadj: -0.00063, p = 0.3307) and the distribution of alleles among the Pvmdr1 SNPs and MS haplotypes showed no significant associations with IC₅₀ values.

Conclusions

Plasmodium vivax was found to be susceptible to CQ drug treatment in both the in vivo therapeutic drug study and the in vitro drug assay. Though the mutant 1076L of Pvmdr1 was found in a majority of isolates tested, this single mutation did not associate with CQ resistance. MS haplotypes revealed strong heterogeneity in this population, indicating a low probability of reinfection with highly related haplotypes.

Multiple splenic infarcts in acute Plasmodium vivax malaria: a rare case report

In tropical countries like India, malaria has been one of the most common parasitic illnesses leading to frequent hospitalization and causing major economic burden among the masses. Although Plasmodium vivax infection is considered to be benign, in contrast to Plasmodium falciparum infection which is notorious for its severe splenic complications can occur frequently. Splenomegaly tends not to receive special attention, as it is not usually accompanied by any symptoms and can be gradually resolved via standard antimalarial therapy. Splenic infarction, although rarely attributable to malaria in an endemic region with high parasitemia, can be a rare presentation of this disease entity.

Urban health in India: who is responsible?

Urban health has received relatively less focus compared with rural health in India, especially the health of the urban poor. Rapid urbanization in India has been accompanied by an increase in population in urban slums and shanty towns, which are also very inadequately covered by basic amenities, including health services. The paper presents existing and new evidence that shows that health inequities exist between the poor and the non-poor in urban areas, even in better-off states in India. The lack of evidence-based policies that cut across sectors continues to be a main feature of the urban health scenario. Although the problems of urban health are more complex than those of rural health, the paper argues that it is possible to make a beginning fairly quickly by (i) collecting more evidence of health status and inequities in urban areas and (ii) correcting major inadequacies in infrastructure-both health and non-health-without waiting for major policy overhauls.

Assessment of malaria incidence using the Richards model in Arunachal Pradesh, India

Monitoring of malaria intensity in terrain regions of Arunachal Pradesh, India is very difficult as the dynamics of mosquito populations varies to a large extent due to altitude and frequent changes in climatic conditions. There is a scarcity of information on the influence of climatic factors on malaria morbidity in Arunachal Pradesh. Hence, a pilot study was conducted from 2006 to 2010 to understand malaria transmission dynamics, seasonal distribution and disease morbidity. Plasmodium vivax and P. falciparum are the two major parasites for malaria transmission in Arunachal Pradesh. Out of 142 558 malaria cases analysed from 2006 to 2010, P. vivax infection contributed 72·1% followed by P. falciparum (27·9%). However, the overall morbidity of malaria declined from 37/1000 in 2006 to 18/1000 population in 2010. From this study it was observed that the temporal distribution of malaria cases varied between districts and high morbidity rates were reported mostly during the wet season. To understand malaria transmission dynamics in the study area, the Richards model was used to predict malaria cases. The output of the results from this model predicted a higher number of malaria cases (K) during 2006 and a gradual decline in subsequent years. Similarly, the growth rate r, and exponential deviation α, were almost identical for all the years, which shows that the Richards model is the most suitable model for the prediction of malaria cases.

Dysregulation of cytokines expression in complicated falciparum malaria with increased TGF-β and IFN-γ and decreased IL-2 and IL-12

BACKGROUND

In Plasmodium falciparum infections, proinflammatory cytokine response is implicated in control of parasite multiplication as well as in disease pathogenesis. However, the regulation of proinflammatory and anti-inflammatory cytokine balance and its relation to disease severity remains poorly understood.

METHODS

We examined cytokines gene expression by quantitative real time-PCR technique in a case control study comprising of P. falciparum infected (n=58) and non infected (n=30) groups. P. falciparum infected were further stratified as complicated and uncomplicated as per WHO criterion and parasitaemia levels.

RESULTS

Higher expression of IL-2, IL-12α and TGF-β with decreased levels of IL-10 was seen in P. falciparum positivity. Complicated malaria was associated with enhanced expression of IFN-γ and TGF-β but lower IL-2 and IL-12α in comparison to uncomplicated malaria. Modeling of data suggested higher expression of IL-12α to be predictive of uncomplicated malaria [Odds ratio=3.074, 95% CI (1.254-7.536)] and was negatively associated with complicated malaria outcome (p=0.014). Interestingly, the probability of complicated malaria in males with elevated TNF-α expression was three times higher [p=0.05; Odds ratio=3.412, 95% CI (0.98-11.848)]. Age was also seen to be a factor with higher IL-8 in diseased young (p=0.012).

CONCLUSION

Our data suggested induction of balanced cytokine response in uncomplicated malaria while cytokine dysregulation with a role for TGF-β was indicated in complicated malaria. TH cells did not appear to be the source of increased IFN-γ expression associated with malaria severity.

Public health system readiness to treat malaria in Odisha State of India

Background

Early diagnosis and prompt treatment is a cornerstone of malaria control. In India, artemisinin combination therapy (ACT) became the first-line treatment for falciparum malaria and rapid diagnostic test (RDTs) kits were recommended for use at the grass-root level in the new malaria treatment policy (2010). Odisha State contributes about one-fourth of the total Indian malaria burden and 40% of falciparum infection. The present study assessed the health system readiness to deploy RDTs and ACT for malaria control across the State.

Methods

Data collection was carried out from February to July 2012. Five of Odisha’s 30 districts were selected through stratified random sampling, with stratification based on the phased roll-out of ACT and RDT. Two administrative 'blocks’ were selected randomly in each district and data collected through health facility, auxiliary nurse midwives (ANMs) and accredited social health activist (ASHAs) assessments. Key informant interviews were conducted with individuals involved in the implementation of the malaria control programme.

Results

Of the 220 ANMs interviewed, 51.4% had been trained in malaria case management, including the use of ACT and RDT. A high proportion of ANM (80%) and AHSA (77%) had the necessary level of knowledge to be able to use RDT for malaria diagnosis. The proportion of ASHAs trained on malaria case management was 88.9% (209/235). However, 71% of ANM and 55% of ASHAs usually referred falciparum-positive patients to the health facility for treatment, the major reason for referral being the non-availability of drugs at the ANM and ASHA level.

Conclusion

The relatively high level of knowledge about how to diagnose and treat malaria at the grass-root level was undermined by the poor availability of RDTs, ACT and primaquine tablets. This was associated with an unnecessarily high referral rate and potential delays in the treatment of this potentially life-threatening infection. Improvements in the supply chain for RDTs and ACT could dramatically enhance the effectiveness of malaria control in Odisha.

ITS2 characterization and Anopheles species identification of the subgenus Cellia

In Mizoram, the origin and molecular nature of Anopheles species is poorly understood, despite the region having high malarial incidence and rich biodiversity. A diagnostic PCR assay for distinguishing the Cellia subgenera members of Anopheles species was developed based on the interspecific ITS2 variation. No intraspecific variation was found and the size (362-604bp) and GC content (48.8-58.9%) of the ITS2 were highly variable among Anophelines. The ITS2 of A. vagus is significantly longer than those of other Anopheles species. Significant relationship was observed among repeats, minimum free energy and RNA secondary structures. Different types of microsatellites were identified and among them dinucleotide, pentanucleotide and polynucleotide microsatellites were predominant. Variation in the length of the ITS2 between species was due to indels in simple repeats. Four domain types of RNA secondary structures were identified and the lowest free energy values were predicted using the computer software, RNAfold. Types I and II were observed only in Neocellia and Myzomyia series and Types III and IV were common in Neocellia and Pyretophorus series. ITS2-based PCR protocol provides a means for vector ecologists, malaria epidemiologists and control personnel to accurately identify members of the subgenera Cellia and a better understanding of their genomic status in Mizoram.

Community perceptions on malaria and care-seeking practices in endemic Indian settings: policy implications for the malaria control programme

BACKGROUND

The focus of India's National Malaria Programme witnessed a paradigm shift recently from health facility to community-based approaches. The current thrust is on diagnosing and treating malaria by community health workers and prevention through free provision of long-lasting insecticidal nets. However, appropriate community awareness and practice are inevitable for the effectiveness of such efforts. In this context, the study assessed community perceptions and practice on malaria and similar febrile illnesses. This evidence base is intended to direct the roll-out of the new strategies and improve community acceptance and utilization of services.

METHODS

A qualitative study involving 26 focus group discussions and 40 key informant interviews was conducted in two districts of Odisha State in India. The key points of discussion were centred on community perceptions and practice regarding malaria prevention and treatment. Thematic analysis of data was performed.

RESULTS

The 272 respondents consisted of 50% females, three-quarter scheduled tribe community and 30% students. A half of them were literates. Malaria was reported to be the most common disease in their settings with multiple modes of transmission by the FGD participants. Adoption of prevention methods was seasonal with perceived mosquito density. The reported use of bed nets was low and the utilization was determined by seasonality, affordability, intoxication and alternate uses of nets. Although respondents were aware of malaria-related symptoms, care-seeking from traditional healers and unqualified providers was prevalent. The respondents expressed lack of trust in the community health workers due to frequent drug stock-outs. The major determinants of health care seeking were socio-cultural beliefs, age, gender, faith in the service provider, proximity, poverty, and perceived effectiveness of available services.

CONCLUSION

Apart from the socio-cultural and behavioural factors, the availability of acceptable care can modulate the community perceptions and practices on malaria management. The current community awareness on symptoms of malaria and prevention is fair, yet the prevention and treatment practices are not optimal. Promoting active community involvement and ownership in malaria control and management through strengthening community based organizations would be relevant. Further, timely availability of drugs and commodities at the community level can improve their confidence in the public health system.

Impact of enhanced malaria control on the competition between Plasmodium falciparum and Plasmodium vivax in India

The primary focus of malaria research and control has been on Plasmodium falciparum, the most severe of the four Plasmodium species causing human disease. However, the presence of both P. falciparum and Plasmodium vivax occurs in several countries, including India. We developed a mathematical model describing the dynamics of P. vivax and P. falciparum in the human and mosquito populations and fit this model to Indian clinical case data to understand how enhanced control measures affect the competition between the two Plasmodium species. Around 1997, funding for malaria control in India increased dramatically. Our model predicts that if India had not improved its control strategy, the two species of Plasmodium would continue to coexist. To determine which control measures contributed the most to the decline in the number of cases after 1997, we compared the fit of seven models to the 1997-2010 clinical case data. From this, we determined that increased use of bednets contributed the most to case reduction. During the enhanced control period, the best model predicts that P. vivax is out-competing P. falciparum. However, the reproduction numbers are extremely close to the invasion boundaries. Consequently, we cannot be confident that this outcome is the true future of malaria in India. We address this uncertainty by performing a parametric bootstrapping procedure for each of the seven models. This procedure, applied to the enhanced control period, revealed that the best model predicts that P. vivax outcompeting P. falciparum is the most likely outcome, whereas the remaining candidate models predict the opposite. Moreover, the predictions of the top model are counter to what one expects based on the case data alone. Although the proportion of cases due to falciparum has been increasing, the best fitting model reveals that this observation is insufficient to draw conclusions about the longterm competitive outcome of the two species.

Epidemiology of malaria in endemic areas

Malaria infection is still to be considered a major public health problem in those 106 countries where the risk of contracting the infection with one or more of the Plasmodium species exists. According to estimates from the World Health Organization, over 200 million cases and about 655.000 deaths have occurred in 2010. Estimating the real health and social burden of the disease is a difficult task, because many of the malaria endemic countries have limited diagnostic resources, especially in rural settings where conditions with similar clinical picture may coexist in the same geographical areas. Moreover, asymptomatic parasitaemia may occur in high transmission areas after childhood, when anti-malaria semi-immunity occurs. Malaria endemicity and control activities are very complex issues, that are influenced by factors related to the host, to the parasite, to the vector, to the environment and to the health system capacity to fully implement available anti-malaria weapons such as rapid diagnostic tests, artemisinin-based combination treatment, impregnated bed-nets and insecticide residual spraying while waiting for an effective vaccine to be made available.

Use of Poisson spatiotemporal regression models for the Brazilian Amazon Forest: malaria count data

INTRODUCTION

Malaria is a serious problem in the Brazilian Amazon region, and the detection of possible risk factors could be of great interest for public health authorities. The objective of this article was to investigate the association between environmental variables and the yearly registers of malaria in the Amazon region using bayesian spatiotemporal methods.

METHODS

We used Poisson spatiotemporal regression models to analyze the Brazilian Amazon forest malaria count for the period from 1999 to 2008. In this study, we included some covariates that could be important in the yearly prediction of malaria, such as deforestation rate. We obtained the inferences using a bayesian approach and Markov Chain Monte Carlo (MCMC) methods to simulate samples for the joint posterior distribution of interest. The discrimination of different models was also discussed.

RESULTS

The model proposed here suggests that deforestation rate, the number of inhabitants per km², and the human development index (HDI) are important in the prediction of malaria cases.

CONCLUSIONS

It is possible to conclude that human development, population growth, deforestation, and their associated ecological alterations are conducive to increasing malaria risk. We conclude that the use of Poisson regression models that capture the spatial and temporal effects under the bayesian paradigm is a good strategy for modeling malaria counts.

Knowledge, attitude and practice of malaria transmission and its prevention among the school going adolescents in Wardha District, Central India

BACKGROUND

Malaria causes 216 million cases and an estimated 655000 deaths in 2010 in the world. 80.5% of the 109 billion population of India lives in malaria risk areas. The purpose of this study was to determine the knowledge, attitude and practices of malaria transmission and its prevention among the school going adolescents.

METHODOLOGY

A cross sectional study was conducted among school going adolescents in the rural area of District Wardha, Maharashtra, Central India. 1096 adolescents from eight government secondary schools were randomly selected. A pre-designed, pre-tested questionnaire was used for data collection. Data thus generated was entered in Microsoft Excel and analyzed using Epi Info 6.04 software package. Chi square value was used for testing the statistical significance.

RESULTS

The mean age of the school going adolescents was 13.45 ± 1.91, for boys 13.43 ± 1.99 and 13.48 ± 1.85 year old for girls. About 84.7% of the respondents heard about the malaria disease and. 8.6% were aware about the causative agent. Transmission of malaria by mosquito bite was known to 69.8% of the adolescents. This was found significantly associated with male gender (X2 = 4.21, p = 0.03). Some of the adolescents had misconception regarding the mode of transmission of malaria like houseflies (32.8%). Nearly half (51.1%) of the adolescents had knowledge of symptoms of malaria as fever. None of the adolescents were aware about the new strategy of insecticide treated bed nets. Majority of the adolescents (57.7%) knew commonest breeding habits of mosquitoes as dirty stagnant water. The main source of information about malaria to most of the adolescents was television and radio (51.7%). About 47.4% of the adolescents practiced the prevention of breeding places of the mosquitoes by cleaning the surrounding. Nearly one fifth (20.7%) of the adolescents were using mosquito net. During the study, 66 (6.02%) adolescents were suffering from fever out of that 12.1% adolescents had taken self medication.

CONCLUSION

Despite widespread knowledge about the morbidity of malaria, understanding about its transmission, treatment and prevention was low. It is imperative to involve the health workers to provide active support and empower teachers with information about malaria causation and prevention strategies so that such knowledge could be passed on to learners.

Malaria in India: the center for the study of complex malaria in India

Malaria is a major public health problem in India and one which contributes significantly to the overall malaria burden in Southeast Asia. The National Vector Borne Disease Control Program of India reported ∼1.6 million cases and ∼1100 malaria deaths in 2009. Some experts argue that this is a serious underestimation and that the actual number of malaria cases per year is likely between 9 and 50 times greater, with an approximate 13-fold underestimation of malaria-related mortality. The difficulty in making these estimations is further exacerbated by (i) highly variable malaria eco-epidemiological profiles, (ii) the transmission and overlap of multiple Plasmodium species and Anopheles vectors, (iii) increasing antimalarial drug resistance and insecticide resistance, and (iv) the impact of climate change on each of these variables. Simply stated, the burden of malaria in India is complex. Here we describe plans for a Center for the Study of Complex Malaria in India (CSCMi), one of ten International Centers of Excellence in Malaria Research (ICEMRs) located in malarious regions of the world recently funded by the National Institute of Allergy and Infectious Diseases, National Institutes of Health. The CSCMi is a close partnership between Indian and United States scientists, and aims to address major gaps in our understanding of the complexity of malaria in India, including changing patterns of epidemiology, vector biology and control, drug resistance, and parasite genomics. We hope that such a multidisciplinary approach that integrates clinical and field studies with laboratory, molecular, and genomic methods will provide a powerful combination for malaria control and prevention in India.

Malaria in South Asia: prevalence and control

The "Malaria Evolution in South Asia" (MESA) program project is an International Center of Excellence for Malaria Research (ICEMR) sponsored by the US National Institutes of Health. This US-India collaborative program will study the origin of genetic diversity of malaria parasites and their selection on the Indian subcontinent. This knowledge should contribute to a better understanding of unexpected disease outbreaks and unpredictable disease presentations from Plasmodium falciparum and Plasmodium vivax infections. In this first of two reviews, we highlight malaria prevalence in India. In particular, we draw attention to variations in distribution of different human-parasites and different vectors, variation in drug resistance traits, and multiple forms of clinical presentations. Uneven malaria severity in India is often attributed to large discrepancies in health care accessibility as well as human migrations within the country and across neighboring borders. Poor access to health care goes hand in hand with poor reporting from some of the same areas, combining to possibly distort disease prevalence and death from malaria in some parts of India. Corrections are underway in the form of increased resources for disease control, greater engagement of village-level health workers for early diagnosis and treatment, and possibly new public-private partnerships activities accompanying traditional national malaria control programs in the most severely affected areas. A second accompanying review raises the possibility that, beyond uneven health care, evolutionary pressures may alter malaria parasites in ways that contribute to severe disease in India, particularly in the NE corridor of India bordering Myanmar Narayanasamy et al., 2012.

Drug resistance in malaria

Antimalarial chemotherapy is an important component of all malaria control programmes throughout the world. This is especially so in light of the fact that there are no antimalarial vaccines which are available for clinical use at present. Emergence and spread of malaria parasites which are resistant to many of the available antimalarials today is, therefore, a major cause for concern. Till date, resistance to all groups of antimalarials excluding artemisinin has been reported. In recent years, in vitro resistance to even artemisinin has been described. While resistance to antibacterial agents has come to prominence as a clinical problem in recent years, antiparasitic resistance in general and antimalarial resistance in particular has not received much attention, especially in the Indian scenario. The present review deals with commonly used antimalarial drugs and the mechanisms of resistance to them. Various methods of detecting antimalarial resistance and avoiding the same have also been dealt with. Newer parasite targets which can be used in developing newer antimalarial agents and antimalarials obtained from plants have also been mentioned.

INDIA'S APPROACH TO ELIMINATING PLASMODIUM FALCIPARUM MALARIA: A MODELING PERSPECTIVE

Approximately one-third of the world's population that is at risk to malaria lives in India. Plasmodium falciparum, a deadly form of malaria, accounts for about 50% of the cases there. Since 1940s, India has used a number of programs to combat the disease with variable success. Since 1998, the total numbers of malaria cases, and in particular P. falciparum cases, have been steadily declining, making India one of the success stories among the countries supported by the Roll Back Malaria (RBM) Partnership. This article considers India's P. falciparum control methods from the perspective of a Ross-MacDonald type model. The model is fitted to the P. falciparum cases in India over the period 1983–2009. We focus on the disease reproduction number as being a measure of success of programs. Before the start of RBM measures, the disease reproduction number was [Formula: see text], meaning that the incidence of disease was increasing among the population. With the new control measures [Formula: see text], suggesting that P.falciparum cases may be declining to zero but extremely slowly. The model here projects 0.734 million cases of P. falciparum malaria for 2010, down from 1.14 million cases in 2000. This impressive 36% decrease falls somewhat short of the RBM's goal of 50% reduction. However, a sensitivity analysis of the disease reproduction number done here suggests that India's control programs do apply controls at the most critical points in the disease cycle; namely, mosquito biting rates, mosquito mortality, and treatment of infected humans. This suggests that as more resources become available, they should be applied to strengthen these controls. The novelty here is in fitting recent data on malaria from India to derive current values of the disease reproduction number.

Theoretical investigation of malaria prevalence in two Indian cities using the response surface method

Background

Elucidation of the relationships between malaria incidence and climatic and non-climatic factors in a region is of utmost importance in understanding the causative factors of disease spread and design of control strategies. Very often malaria prevalence data is restricted to short time scales (months to few years). This demands application of rigorous statistical modelling techniques for analysis and prediction. The monthly malaria prevalence data for three to five years from two cities in southern India, situated in two different climatic zones, are studied to capture their dependence on climatic factors.

Methods

The statistical technique of response surface method (RSM) is applied for the first time to study any epidemiological data. A new step-by-step model reduction technique is proposed to refine the initial model obtained from RSM. This provides a simpler structure and gives better fit. This combined approach is applied to two types of epidemiological data (Slide Positivity Rates values and Total Malaria cases), for two cities in India with varying strengths of disease prevalence and environmental conditions.

Results

The study on these data sets reveals that RSM can be used successfully to elucidate the important environmental factors influencing the transmission of the disease by analysing short epidemiological time series. The proposed approach has high predictive ability over relatively long time horizons.

Conclusions

This method promises to provide reliable forecast of malaria incidence across varying environmental conditions, which may help in designing useful control programmes for malaria.

Global status of DDT and its alternatives for use in vector control to prevent disease

In this article I reviewed the status of dichlorodiphenyltrichloroethane (DDT), used for disease vector control, and its benefits and risks in relation to the available alternatives. Contemporary data on DDT use were obtained from questionnaires and reports as well as a Scopus search to retrieve published articles. Nearly 14 countries use DDT for disease control, and several others are reintroducing DDT. Concerns about the continued use of DDT are fueled by recent reports of high levels of human exposure associated with indoor spraying amid accumulating evidence on chronic health effects. There are signs that more malaria vectors are becoming resistant to the toxic action of DDT. Effective chemical methods are available as immediate alternatives to DDT, but the development of resistance is undermining the efficacy of insecticidal tools. Nonchemical methods are potentially important, but their effectiveness at program level needs urgent study. To reduce reliance on DDT, support is needed for integrated and multipartner strategies of vector control. Integrated vector management provides a framework for developing and implementing effective technologies and strategies as sustainable alternatives to reliance on DDT.

Impacts of climate change on public health in India: future research directions

BACKGROUND

Climate change and associated increases in climate variability will likely further exacerbate global health disparities. More research is needed, particularly in developing countries, to accurately predict the anticipated impacts and inform effective interventions.

OBJECTIVES

Building on the information presented at the 2009 Joint Indo-U.S. Workshop on Climate Change and Health in Goa, India, we reviewed relevant literature and data, addressed gaps in knowledge, and identified priorities and strategies for future research in India.

DISCUSSION

The scope of the problem in India is enormous, based on the potential for climate change and variability to exacerbate endemic malaria, dengue, yellow fever, cholera, and chikungunya, as well as chronic diseases, particularly among the millions of people who already experience poor sanitation, pollution, malnutrition, and a shortage of drinking water. Ongoing efforts to study these risks were discussed but remain scant. A universal theme of the recommendations developed was the importance of improving the surveillance, monitoring, and integration of meteorological, environmental, geospatial, and health data while working in parallel to implement adaptation strategies.

CONCLUSIONS

It will be critical for India to invest in improvements in information infrastructure that are innovative and that promote interdisciplinary collaborations while embarking on adaptation strategies. This will require unprecedented levels of collaboration across diverse institutions in India and abroad. The data can be used in research on the likely impacts of climate change on health that reflect India's diverse climates and populations. Local human and technical capacities for risk communication and promoting adaptive behavior must also be enhanced.

Antimalarial drug resistance of Plasmodium falciparum in India: changes over time and space

After the launch of the National Malaria Control Programme in 1953, the number of malaria cases reported in India fell to an all-time low of 0·1 million in 1965. However, the initial success could not be maintained and a resurgence of malaria began in the late 1960s. Resistance of Plasmodium falciparum to chloroquine was first reported in 1973 and increases in antimalarial resistance, along with rapid urbanisation and labour migration, complicated the challenge that India's large geographical area and population size already pose for malaria control. Although several institutions have done drug-resistance monitoring in India, a complete analysis of countrywide data across institutions does not exist. We did a systematic review of P falciparum malaria drug-efficacy studies in India to summarise drug-resistance data and describe changes over the past 30 years to inform future policy. Continued use of chloroquine for treatment of P falciparum malaria in India will likely be ineffective. Resistance to sulfa-pyrimethamine should be closely monitored to protect the effectiveness of treatment with artesunate plus sulfadoxine-pyrimethamine, which is the new first-line treatment for P falciparum malaria. Strategies to reduce the emergence and spread of future drug resistance need to be proactive and supported by intensive monitoring.

Cost-effectiveness of pre-referral antimalarial, antibacterial, and combined rectal formulations for severe febrile illness

Background

Malaria and bacterial infections account for most infectious disease deaths in developing countries. Prompt treatment saves lives, but rapid deterioration often prevents the use of oral therapies; delays in reaching health facilities providing parenteral interventions are common. Rapidly and reliably absorbed antimalarial/antibacterial rectal formulations used in the community could prevent deaths and disabilities. Rectal antimalarial treatments are currently available; rectal antibacterial treatments are yet to be developed. Assessment of the likely cost-effectiveness of these interventions will inform research priorities and implementation.

Methods and Findings

The burden of malaria and bacterial infections worldwide and in Sub-Saharan and Southern Africa (SSA) and South and South-East Asia (SEA) was summarised using published data. The additional healthcare costs (US$) per death and per Disability Adjusted Life Year (DALY) avoided following pre-referral treatment of severe febrile illness with rectal antimalarials, antibacterials or combined antimalarial/antibacterials in populations at malaria risk in SSA/SEA were assessed. 46 million severe malaria and bacterial infections and 5 million deaths occur worldwide each year, mostly in SSA/SEA. At annual delivery costs of $0.02/capita and 100% coverage, rectal antimalarials ($2 per dose) would avert 240,000 deaths in SSA and 7,000 deaths in SEA at $5 and $177 per DALY avoided, respectively; rectal antibacterials ($2 per dose) would avert 130,000 deaths in SSA and 27,000 deaths in SEA at $19 and $97 per DALY avoided, respectively. Combined rectal formulations ($2.50 per dose) would avert 370,000 deaths in SSA and 33,000 deaths in SEA at $8 and $79 per DALY avoided, respectively, and are a cost-effective alternative to rectal antimalarials or antibacterials alone.

Conclusions

Antimalarial, antibacterial and combined rectal formulations are likely to be cost-effective interventions for severe febrile illness in the community. Attention should focus on developing effective rectal antibacterials and ensuring that these lifesaving treatments are used in a cost-effective manner.

Presumptive treatment for malaria is not justified in children receiving cancer chemotherapy

BACKGROUND

Predominant etiologies of febrile neutropenia (FN) during the course of cancer chemotherapy include infections with bacteria, fungi, and viruses. Infection with malarial parasite is a possibility in regions that are endemic for malaria. Over-diagnosis and over-treatment of malaria is increasingly being recognized as a serious concern in malaria endemic regions. Aim was to determine the incidence of malarial infection in episodes of FN in children receiving chemotherapy for malignant disorders.

METHODS

Children, with malignant disorders, on chemotherapy, who fulfilled the definition of FN were enrolled prospectively. Standard microscopy, quantitative buffy coat, and antigen detection (OptiMAL) were performed in each episode of FN.

RESULTS

One hundred episodes of FN involving 82 children were investigated. The age ranged from 2 to 13 years (mean: 5.8 ± 2.8). Eighty-one episodes were in children with acute lymphoblastic leukemia, 15 in acute myeloid leukemia, and remaining 4 in other malignancies. Evidence for malaria was not found in any case by any of the three methods.

CONCLUSIONS

Malaria was not found to be a causative agent for FN in children with various malignant disorders, in a region with low endemicity for malaria. Presumptive administration of antimalarials in children with FN is unjustified. Pediatric oncologists constantly face the challenge of managing febrile illnesses in immunocompromised patients. Those practicing in malaria endemic regions can effectively exploit diagnostic tools for malaria for a rational decision.

Mosquito larvicidal potential of potash alum against malaria vector Anopheles stephensi (Liston)

Mosquito larviciding may prove to be an effective tool for incorporating into integrated vector management strategies for reducing malaria transmission. Here, we report the potential of potash alum, a traditionally known salt in Indian Ayurveda and Chinese medicine system, in malaria vector control by evaluating its aqueous suspension as larvicide and growth disruptor of Anopheles stephensi, under laboratory conditions. Immature stages of the mosquito were tested using WHO guidelines. 50 and 90% lethal concentrations among various larvae ranged between 2.1 to 48.74 ppm and 15.78 to 93.11 ppm, respectively. The results indicated that larvicidal effects of potash alum were comparable to various biological and chemical insecticides. The study provides considerable scope in exploiting local indigenous resources for the control of nuisance mosquito vectors.

In vitro antiplasmodial and antimicrobial potential of Tagetes erecta roots

CONTEXT

Among strategies to combat malaria, the search for newer antimalarial compounds is a priority. Traditionally, Tagetes erecta Linn. (Compositae) has been used for the treatment of various diseases and ailments including malaria.

OBJECTIVE

Five successive extracts (petroleum ether, chloroform, ethyl acetate, methanol and aqueous) of the roots of T. erecta and a new bithienyl compound, 2-hydroxymethyl-non-3-ynoic acid 2-[2,2']-bithiophenyl-5-ethyl ester from the roots of the plant, were evaluated for in vitro antiplasmodial activity against chloroquine sensitive and resistant strains of Plasmodium falciparum. The extracts were also tested for in vitro antimicrobial activity against seven microbial strains.

MATERIALS AND METHODS

The antiplasmodial screening was carried out using the schizont maturation inhibition assay. Preliminary antimicrobial screening was carried out using the agar well assay followed by determination of minimum inhibitory concentration (MIC) using two-fold serial dilutions.

RESULTS

Among all the extracts tested, the ethyl acetate fraction exhibited significant antiplasmodial efficacy with the 50% inhibitory concentrations (IC(50)) of 0.02 and 0.07 mg/mL against the chloroquine sensitive and resistant strains of Plasmodium falciparum respectively. The new bithienyl compound also showed significant schizonticidal activity against both chloroquine sensitive and resistant strains of Plasmodium falciparum with the IC(50) values of 0.01 and 0.02 mg/mL. Additionally, all extracts exhibited significant antimicrobial activity against three Gram-positive and two Gram-negative bacterial and two fungal strains with MIC values ranging between 12.5-100 µg/mL.

DISCUSSION

The new bithienyl compound was profoundly able to arrest the ring stages of the malarial parasites thereby exerting its antiplasmodial effect.

CONCLUSION

The observations provide support for the ethnobotanical use of the plant.

Persistent transmission of malaria in Garo hills of Meghalaya bordering Bangladesh, north-east India

Background

Malaria is endemic in Garo hills of Meghalaya, and death cases are reported annually. Plasmodium falciparum is the major parasite, and is solely responsible for each malaria-attributable death case. Garo hills are categorized high-risk for drug-resistant malaria; however, there exists no data on malaria transmitting mosquitoes prevalent in the region. Included in this report are entomological observations with particular reference to vector biology characteristics for devising situation specific intervention strategies for disease transmission reduction.

Methods

The epidemiological data of the West Garo hills have been reviewed retrospectively for 2001-2009 to ascertain the disease transmission profile given the existing interventions. Point prevalence study was conducted in Dalu Community Health Centre that lies in close proximity to international border with Bangladesh to ascertain the true prevalence of malaria, and parasite species. Mosquito collections were made in human dwellings of malaria endemic villages aiming at vector incrimination, and to study relative abundance, resting and feeding preferences, and their present susceptibility status to DDT.

Results

Investigations revealed that the West Garo hill district is co-endemic for Plasmodium falciparum and Plasmodium vivax, but P. falciparum was the predominant infection (> 82%). Malaria transmission was perennial and persistent with seasonal peak during May-July corresponding to months of high rainfall. Entomological collections revealed that Anopheles minimus was the predominant species that was incriminated by detection of sporozoites in salivary glands (infection rate 2.27%), and was ascertained to be fully susceptible to DDT.

Conclusion

For the control of malaria, improved diagnosis and sustained supply of drugs for artemisinin-based combination therapy are strongly advocated, which should be enforced for treatment of every single case of P. falciparum. Greater political commitment is called for organized vector control operations along border/high-risk areas to contain the spread of drug-resistant malaria, and averting impending disease outbreaks.

Availability and utilization of malaria prevention strategies in pregnancy in eastern India

Background

Malaria in pregnancy in India, as elsewhere, is responsible for maternal anemia and adverse pregnancy outcomes such as low birth weight and preterm birth.

It is not known whether prevention and treatment strategies for malaria in pregnancy (case management, insecticide-treated bednets, intermittent preventive therapy) are widely utilized in India.

Methods

This cross-sectional study was conducted during 2006-2008 in two states of India, Jharkhand and Chhattisgarh, at 7 facilities representing a range of rural and urban populations and areas of more versus less stable malaria transmission. 280 antenatal visits (40/site) were observed by study personnel coupled with exit interviews of pregnant women to assess emphasis upon, availability and utilization of malaria prevention practices by health workers and pregnant women. The facilities were assessed for the availability of antimalarials, lab supplies and bednets.

Results

All participating facilities were equipped to perform malaria blood smears; none used rapid diagnostic tests. Chloroquine, endorsed for chemoprophylaxis during pregnancy by the government at the time of the study, was stocked regularly at all facilities although the quantity stocked varied. Availability of alternative antimalarials for use in pregnancy was less consistent. In Jharkhand, no health worker recommended bednet use during the antenatal visit yet over 90% of pregnant women had bednets in their household. In Chhattisgarh, bednets were available at all facilities but only 14.4% of health workers recommended their use. 40% of the pregnant women interviewed had bednets in their household. Only 1.4% of all households owned an insecticide-treated bednet; yet 40% of all women reported their households had been sprayed with insecticide. Antimalarial chemoprophylaxis with chloroquine was prescribed in only 2 (0.7%) and intermittent preventive therapy prescribed in only one (0.4%) of the 280 observed visits.

Conclusions

A disconnect remains between routine antenatal practices in India and known strategies to prevent and treat malaria in pregnancy. Prevention strategies, in particular the use of insecticide-treated bednets, are underutilized. Gaps highlighted by this study combined with recent estimates of the prevalence of malaria during pregnancy in these areas should be used to revise governmental policy and target increased educational efforts among health care workers and pregnant women.

Malaria

Malaria has had a greater impact on world history than any other infectious disease. More than 300 to 500 million individuals worldwide are infected with Plasmodium spp, and 1.5 to 2.7 million people a year, most of whom are children, die from the infection. Malaria is endemic in over 90 countries in which 2400 million people live; this represents 40% of the world's population. Approximately 90% of malaria deaths occur in Africa. Despite continuing efforts in vaccine development, malaria prevention is difficult, and no drug is universally effective. This article examines malaria caused by the 4 most common Plasmodium spp that infect humans, P vivax, P ovale, P malariae, and P falciparum, as well as mixed infections and the simian parasite P knowlesi. A comprehensive review of the microbiology, clinical presentation, pathogenesis, diagnosis, and treatment of these forms of malaria is given.

Field and laboratory comparative evaluation of rapid malaria diagnostic tests versus traditional and molecular techniques in India

Background

Malaria presents a diagnostic challenge in most tropical countries. Microscopy remains the gold standard for diagnosing malaria infections in clinical practice and research. However, microscopy is labour intensive, requires significant skills and time, which causes therapeutic delays. The objective of obtaining result quickly from the examination of blood samples from patients with suspected malaria is now made possible with the introduction of rapid malaria diagnostic tests (RDTs). Several RDTs are available, which are fast, reliable and simple to use and can detect Plasmodium falciparum and non-falciparum infections or both. A study was conducted in tribal areas of central India to measure the overall performance of several RDTs for diagnosis of P. falciparum and non-falciparum infections in comparison with traditional and molecular techniques. Such data will be used to guide procurement decisions of policy makers and programme managers.

Methods

Five commercially available RDTs were tested simultaneously in field in parallel with peripheral blood smears in outbreak-affected areas. The evaluation is designed to provide comparative data on the performance of each RDT. In addition, molecular method i.e. polymerase chain reaction (PCR) was also carried out to compare all three methods.

Results

A total of 372 patients with a clinical suspicion of malaria from Bajag Primary Health Centre (PHC) of district Dindori and Satanwada PHC of district Shivpuri attending the field clinics of Regional Medical Research Centre were included in the study. The analysis revealed that the First Response Malaria Antigen pLDH/HRP2 combo test was 94.7% sensitive (95% CI 89.5-97.7) and 69.9% specific (95% CI 63.6-75.6) for P. falciparum. However, for non-falciparum infections (Plasmodium vivax) the test was 84.2% sensitive (95% CI 72.1-92.5) and 96.5% specific (95% CI 93.8-98.2). The Parascreen represented a good alternative. All other RDTs were relatively less sensitive for both P. falciparum and non-falciparum infections.

Conclusions

The results in this study show comparative performance between microscopy, various RDTs and PCR. Despite some inherent limitation in the five RDTs tested, First Response clearly has an advantage over other RDTs. The results suggest that RDTs could play and will play an important role in malaria diagnosis.

Estimating the global clinical burden of Plasmodium falciparum malaria in 2007

BACKGROUND

The epidemiology of malaria makes surveillance-based methods of estimating its disease burden problematic. Cartographic approaches have provided alternative malaria burden estimates, but there remains widespread misunderstanding about their derivation and fidelity. The aims of this study are to present a new cartographic technique and its application for deriving global clinical burden estimates of Plasmodium falciparum malaria for 2007, and to compare these estimates and their likely precision with those derived under existing surveillance-based approaches.

METHODS AND FINDINGS

In seven of the 87 countries endemic for P. falciparum malaria, the health reporting infrastructure was deemed sufficiently rigorous for case reports to be used verbatim. In the remaining countries, the mapped extent of unstable and stable P. falciparum malaria transmission was first determined. Estimates of the plausible incidence range of clinical cases were then calculated within the spatial limits of unstable transmission. A modelled relationship between clinical incidence and prevalence was used, together with new maps of P. falciparum malaria endemicity, to estimate incidence in areas of stable transmission, and geostatistical joint simulation was used to quantify uncertainty in these estimates at national, regional, and global scales. Combining these estimates for all areas of transmission risk resulted in 451 million (95% credible interval 349-552 million) clinical cases of P. falciparum malaria in 2007. Almost all of this burden of morbidity occurred in areas of stable transmission. More than half of all estimated P. falciparum clinical cases and associated uncertainty occurred in India, Nigeria, the Democratic Republic of the Congo (DRC), and Myanmar (Burma), where 1.405 billion people are at risk. Recent surveillance-based methods of burden estimation were then reviewed and discrepancies in national estimates explored. When these cartographically derived national estimates were ranked according to their relative uncertainty and replaced by surveillance-based estimates in the least certain half, 98% of the global clinical burden continued to be estimated by cartographic techniques.

CONCLUSIONS AND SIGNIFICANCE

Cartographic approaches to burden estimation provide a globally consistent measure of malaria morbidity of known fidelity, and they represent the only plausible method in those malaria-endemic countries with nonfunctional national surveillance. Unacceptable uncertainty in the clinical burden of malaria in only four countries confounds our ability to evaluate needs and monitor progress toward international targets for malaria control at the global scale. National prevalence surveys in each nation would reduce this uncertainty profoundly. Opportunities for further reducing uncertainty in clinical burden estimates by hybridizing alternative burden estimation procedures are also evaluated.

Presence of two alternative kdr-like mutations, L1014F and L1014S, and a novel mutation, V1010L, in the voltage gated Na+ channel of Anopheles culicifacies from Orissa, India

Background

Knockdown resistance in insects resulting from mutation(s) in the voltage gated Na⁺ channel (VGSC) is one of the mechanisms of resistance against DDT and pyrethroids. Recently a point mutation leading to Leu-to-Phe substitution in the VGSC at residue 1014, a most common kdr mutation in insects, was reported in Anopheles culicifacies-a major malaria vector in the Indian subcontinent. This study reports the presence of two additional amino acid substitutions in the VGSC of an An. culicifacies population from Malkangiri district of Orissa, India.

Methods

Anopheles culicifacies sensu lato (s.l.) samples, collected from a population of Malkangiri district of Orissa (India), were sequenced for part of the second transmembrane segment of VGSC and analyzed for the presence of non-synonymous mutations. A new primer introduced restriction analysis-PCR (PIRA-PCR) was developed for the detection of the new mutation L1014S. The An. culicifacies population was genotyped for the presence of L1014F substitution by an amplification refractory mutation system (ARMS) and for L1014S substitutions by using a new PIRA-PCR developed in this study. The results were validated through DNA sequencing.

Results

DNA sequencing of An. culicifacies individuals collected from district Malkangiri revealed the presence of three amino acid substitutions in the IIS6 transmembrane segments of VGSC, each one resulting from a single point mutation. Two alternative point mutations, 3042A>T transversion or 3041T>C transition, were found at residue L1014 leading to Leu (TTA)-to-Phe (TTT) or -Ser (TCA) changes, respectively. A third and novel substitution, Val (GTG)-to-Leu (TTG or CTG), was identified at residue V1010 resulting from either of the two transversions–3028G>T or 3028G>C. The L1014S substitution co-existed with V1010L in all the samples analyzed irrespective of the type of point mutation associated with the latter. The PIRA-PCR strategy developed for the identification of the new mutation L1014S was found specific as evident from DNA sequencing results of respective samples. Since L1014S was found tightly linked to V1010L, no separate assay was developed for the latter mutation. Screening of population using PIRA-PCR assays for 1014S and ARMS for 1014F alleles revealed the presence of all the three amino acid substitutions in low frequency.

Conclusions

This is the first report of the presence of L1014S (homologous to the kdr-e in An. gambiae) and a novel mutation V1010L (resulting from G-to-T or -C transversions) in the VGSC of An. culicifacies in addition to the previously described mutation L1014F. The V1010L substitution was tightly linked to L1014S substitution. A new PIRA-PCR strategy was developed for the detection of L1014S mutation and the linked V1010L mutation.

Global status of DDT and its alternatives for use in vector control to prevent disease

OBJECTIVE

I review the status of dichlorodiphenyltrichloroethane (DDT), used for disease vector control, along with current evidence on its benefits and risks in relation to the available alternatives.

DATA SOURCES AND EXTRACTION

Contemporary data on DDT use were largely obtained from questionnaires and reports. I also conducted a Scopus search to retrieve published articles.

DATA SYNTHESIS

DDT has been recommended as part of the arsenal of insecticides available for indoor residual spraying until suitable alternatives are available. Approximately 14 countries use DDT for disease control, and several countries are preparing to reintroduce DDT. The effectiveness of DDT depends on local settings and merits close consideration in relation to the alternatives. Concerns about the continued use of DDT are fueled by recent reports of high levels of human exposure associated with indoor spraying amid accumulating evidence on chronic health effects. There are signs that more malaria vectors are becoming resistant to the toxic action of DDT, and that resistance is spreading to new countries. A comprehensive cost assessment of DDT versus its alternatives that takes side effects into account is missing. Effective chemical methods are available as immediate alternatives to DDT, but the choice of insecticide class is limited, and in certain areas the development of resistance is undermining the efficacy of insecticidal tools. New insecticides are not expected in the short term. Nonchemical methods are potentially important, but their effectiveness at program level needs urgent study.

CONCLUSIONS

To reduce reliance on DDT, support is needed for integrated and multipartner strategies of vector control and for the continued development of new technologies. Integrated vector management provides a framework for developing and implementing effective technologies and strategies as sustainable alternatives to reliance on DDT.

Why is it important to study malaria epidemiology in India?

Malaria is a major vector-borne disease in India. Based on vast geographic areas with associated topographic and climatic diversity, the variable malaria epidemiology in India is associated with high parasite genetic diversity and rapidly evolving drug resistance, differential distribution of vector species and emerging insecticide resistance and underlying human genetic diversity and past evolutionary histories. Further, changing climatic patterns have possibly changed malaria epidemiology to a great extent. The outcome of these changes is an increased incidence of Plasmodium falciparum over the P. vivax malaria in recent years. Accordingly, the drug and insecticide application policy in India has changed too. The above facts and associated rapid shifting trend of malaria epidemiology makes India a hot-spot for malaria research.

Multi-step polynomial regression method to model and forecast malaria incidence

Malaria is one of the most severe problems faced by the world even today. Understanding the causative factors such as age, sex, social factors, environmental variability etc. as well as underlying transmission dynamics of the disease is important for epidemiological research on malaria and its eradication. Thus, development of suitable modeling approach and methodology, based on the available data on the incidence of the disease and other related factors is of utmost importance. In this study, we developed a simple non-linear regression methodology in modeling and forecasting malaria incidence in Chennai city, India, and predicted future disease incidence with high confidence level. We considered three types of data to develop the regression methodology: a longer time series data of Slide Positivity Rates (SPR) of malaria; a smaller time series data (deaths due to Plasmodium vivax) of one year; and spatial data (zonal distribution of P. vivax deaths) for the city along with the climatic factors, population and previous incidence of the disease. We performed variable selection by simple correlation study, identification of the initial relationship between variables through non-linear curve fitting and used multi-step methods for induction of variables in the non-linear regression analysis along with applied Gauss-Markov models, and ANOVA for testing the prediction, validity and constructing the confidence intervals. The results execute the applicability of our method for different types of data, the autoregressive nature of forecasting, and show high prediction power for both SPR and P. vivax deaths, where the one-lag SPR values plays an influential role and proves useful for better prediction. Different climatic factors are identified as playing crucial role on shaping the disease curve. Further, disease incidence at zonal level and the effect of causative factors on different zonal clusters indicate the pattern of malaria prevalence in the city. The study also demonstrates that with excellent models of climatic forecasts readily available, using this method one can predict the disease incidence at long forecasting horizons, with high degree of efficiency and based on such technique a useful early warning system can be developed region wise or nation wise for disease prevention and control activities.