|Year : 2011 | Volume
| Issue : 2 | Page : 52-53
Current scenario of control of malaria
Division of Clinical Microbiology, All India Institute of Medical Sciences, New Delhi, India
|Date of Web Publication||31-Oct-2011|
Division of Clinical Microbiology, All India Institute of Medical Sciences, New Delhi
|How to cite this article:|
Singh S. Current scenario of control of malaria. Trop Parasitol 2011;1:52-3
Malaria is a major health problem in India and several other tropical countries. It causes death of millions of children, pregnant women and adults. Though all four species of Plasmodium are capable of causing human malaria, falciparum malaria is the most fatal if not treated. Recently, other species of zoonotic origin have also been reported to cause human malaria. The treatment of malaria mainly comprises chloroquine and artemisinin. It is recommended that artemisinin derivatives should always be given in combination with other anti-malarials. When the patient cannot take the drug orally and injections are not available rectal administration of artesunate is recommended. Various options to control malaria have been rolled out and all require community participation.
Malaria is a major health problem in tropical and developing countries of Sub-Saharan Africa and South Asia including India. Billions of inhabitants of these regions face the risk of malaria every season and more than 1 million die every year. Not only residents but visitors to these countries face the risk of contracting malaria. Every year thousands of tourists from the US and Europe export malaria to their native countries after returning from endemic countries. Malaria is also a major killer disease in India, especially in children and pregnant women. Malaria-associated deaths reported annually by the National Vector-borne Disease Control Program are in four digits but in the year 2009-10 this number ranged between 1144 and 767.  However, these figures have been questioned by a recent study which calculated the annual deaths between 1,25,000 and 2,77,000,  a figure which is more than 12-20 times the data provided by the government of India. However, this report has been criticized by national malaria control program managers as well as the World Health Organization (WHO) for the reason that these figures were calculated on the basis of verbal autopsy. Verbal autopsy is a method in which non-medical persons record narratives and answers to specified questions designed by health experts, which are administered to the population under study. In this study also, the proforma had specific questionnaires related to the subjects who died of suspected malaria and were answered by their family members and neighbors. The criticism of this method is that however, the biggest limitation of this method is its questionnaire in which fever is considered the most important response, which may or may not solely be attributed to malaria. The authors of this study have offered strong justifications and cross-examinations of responses, justifying their findings and method of death estimation, while a series of responses from those against this method of death calculation has been published by Lancet in 2010 and 2011.
Without going into the merits and demerits of various data collection methods, it is important to understand that the number of deaths caused by malaria in India is more than the number projected by the government of India. Moreover, no true estimates of the prevalence of various species of Plasmodium are available in national data. It is mainly because the conventional microscopy methods are not sensitive enough to pick all the cases of malaria and lack specificity to differentiate all the species. Though several rapid diagnostic kits are commercially available in the Indian market, only a few are sufficiently sensitive enough to detect low parasitemia of 200/ul in endemic areas. The author has reviewed the WHO evaluation reports (Round I and II) of Rapid Diagnostic Test (RDT) kits for malaria which shows that most of the manufactures failed to achieve the parasite detection score of 75% for Plasmodium vivax, a major cause of chronic malaria.  No commercial kit for the specific detection of Plasmodium ovale and Plasmodium malariae is out in the national program Hence many of the cases of P. ovale and P. malariae are either wrongly classified as Plasmodium vivax or missed.  So there is an urgent need to develop specific multiplex polymerase chain reactions and or quadruple malaria detection line immunoassays and lateral flow rapid test kits with high sensitivity and specificity.
The treatment of Falciparum malaria has been a major challenge in the last few years, specially due to development of drug resistance. A review article by Damodaran, et al., in the current issue of Tropical Parasitology highlights the challenges in the treatment of malaria. The authors highlight that even though the WHO has recommended artemisinin-based combination therapy for uncomplicated malaria, Indian guidelines are slightly different. India recommends that in malaria-endemic areas where chloroquine resistance has not yet been detected, uncomplicated malaria should be treated with chloroquine only. Only in areas where chloroquine resistance has been documented artemisinin should be prescribed. This decision is based on the fact that we need to minimize or delay the exposure of the parasite to this only effective drug. It is rightly apprehended that if the parasite develops resistance to artemisinin, we will have no other remedy in our armamentarium. Therefore, if at all artemisinin has to be administered, it should be given in combination and not alone.
Regarding the difficulties in administering artemisinin, recently Barnes et al.,  carried out a study to see whether artemisinin can be administered through alternative routes. They included 109 children and 35 adults for rectal artesunate administration (single dose of about 10 mg/kg) and compared the disease outcome in those treated with parenteral quinine treatment (10 mg/kg at 0, 4, and 12 h). They found that all artesunate-treated patients had pharmacodynamic or pharmacokinetic evidence of adequate drug absorption. Ninety-two per cent of 87 artesunate-treated children had a 12-h parasite density lower than 60% of baseline, as compared to 14% of those who received quinine (P<0.0001). In adults, parasitemia at 12 h was lower than 60% of baseline in 96% of 27 receiving artesunate, compared with three (38%) of eight receiving quinine (P=0.0009). The authors conclude that a single rectal dose of artesunate is associated with rapid reduction in parasite density in adults and children with moderately severe malaria, within the initial 24 h of treatment. This option is useful for initiation of treatment in patients unable to take oral medication, and where parenteral treatment is not available.
Besides treatment, control of malaria is a major challenge for all the public health policymakers. Various action plans have been formulated. Of these the most significant is the global malaria action plan which is part of the Global Fund to fight AIDS, tuberculosis and malaria. It is an international financing institution that invests the world's money to save lives. To date, it has committed US$ 21.7 billion in 150 countries to support large-scale prevention, treatment and care programs against the three diseases. Also, though most of our efforts have remained focused on Falciparum malaria, which is of course the most malignant form, other forms of malaria should not be ignored.  The malaria control strategies include treatment and prophylaxis of the disease, vaccine development and prevention. Prevention of malaria has several options but they need to be implemented strictly and holistically in all endemic countries simultaneously. These include various vector control measures such as chemical (pesticides), molecular (to create sterile males) or biological (larvicidal) methods. Personal protection may be successful for individual protection but not for controlling or eradicating the disease. Another paper published in the current issue of this journal emphasizes the need of involving gram panchayats for successful control of malaria. 
| References|| |
|1.||National Vector Borne Disease Control Programme, Government of India. Available from http://www.nvbdcp.gov.innone [Last accessed on 2011 May, 17]. |
|2.||Dhingra N, Jha P, Sharma VP, Cohen AA, Jotkar RM, Rodriguez PS, et al. Adult and child malaria mortality in India: a nationally representative mortality survey. Lancet 2010;376:1768-74. |
|3.||Malaria rapid diagnostic test performance. WHO. Switzerland. Available from http://www.who.int/malaria/publications/atoz/9789241599467/en/index.htmlnone [Last accessed on 2011 June, 2] |
|4.||Singh S, Singh N, Handa R. Tumor necrosis factor-alpha in patients with malaria. Indian J Malariol 2000;37:27-33 |
|5.||Damodaran SE, Pradhan P, Pradhan SC. Newer approaches to malaria control. Trop Parasitol 2011;1:57-63. |
|6.||Barnes KI, Mwenechanya J, Tembo M, McIlleron H, Folb PI, Ribeiro I, et al. Efficacy of rectal artesunate compared with parenteral quinine in initial treatment of moderately severe malaria in African children and adults: a randomised study. Lancet 2004;363:1598-605 |
|7.||Baird JK. Eliminating malaria: all of them. Lancet 2010;376:1883-5. |
|8.||Patil RR, Ghosh SK, Tiwari SN. Assessing perceptions about malaria among the elected representatives in rural India. Trop Parasitol 2011;1:83-7. |