Frontline Messages Part-1

The malaria situation in terms of mortality/morbidity has remained static for the past decade in India. Available malaria control measures seem to have lost their punch. There is a need to integrate various malaria control methods to obtain a sustainable impact on Roll Back Malaria. These include bioenvironmental control, legislations, screening of migrant population, intersectorial co-ordination etc. IEC (Information Education and Communication) is one of the aspects important for control. New strategies are needed for control viz. deurbanisation of malaria control, control of drug resistance, training in malariology, assignment of control strategy to elected representatives, more involvement of medical personnel in control programmes etc.

There is an urgent need for a safe and effective malaria vaccine. The problems besetting this endeavour are :
a) antigenic diversity and immune evasion by the parasite
b) lack of good in-vitro correlates
c) lack of large scale production facilities
d) lack of good delivery systems and
e) difficulties in clinical trials, media hype etc.
These hurdles need to be overcome on a priority basis.
The factors responsible for resurgence of malaria were : the role of tribal malaria, construction projects (e.g. railways), increased water usage (e.g. irrigation), rapid transit and migration, resistance of vectors and parasite, and inadequate and half hearted response from health infrastructure in the form of diversion of funds to other projects, withdrawal of insecticidal sprays, large number of vacant posts and introduction of Multi Purpose Worker (MPW) not responsible to any one disease etc. New paradigms of malaria include tribal malaria, deep forest and forest fringe malaria, rural and industrial malaria, border malaria and spread of malaria due to migration. The core areas of research and action consist of prevention of malaria, promotion of active community participation in control, development of user-friendly, sage, low cost personal protective measures, health system research to optimize and integrate malaria program into the health system and the use of sustainable micro environmental methods of Vector Control etc.

Malaria can present with varied symptomatology in addition to the classical fever with 'chills and rigor'. The unusual features include urticaria and even anaphylaxis. Various complications associated with P. falciparum infection include CNS involvement (cerebral malaria), acute renal failure, acute respiratory distress syndrome, hyperpyrexia and hypoglycaemia. Differentail diagnosis includes urinary and respiratory tract infections, meningitis, viral encephalitis, neurovascular accidents, infective endocarditis and even cholangitis. Early diagnosis and treatment are important in reducing fatalities. There is a similar relationship between malaria and HV/AIDS which needs to be investigated further.

The features associated with cerebral malaria occur due to : firstly sequestration of IRBC in microvasculature and secondly, release of cytokines in these areas. The pathogenic effects are due to the letter which further lead to release of nitric oxide, which is nearotoxic. More studies are required in areas like (a) why all patients with high parasitaemia do not develop cerebral malaria (b) do host and parasite factors play a role in pathogenesis (c) what are the consequences of IRBC sequestration on neuronal and glial cells (d) what is the mechanism of microhaemorrhages and (e) what is the exact role of NO in pathogenesis ?
Anaemia had emerged lately as an important manifestation of malaria. Severe anaemia is a potentially fatal compliction of P. falciparum infection, particularly in pregnant women and children. Anaemia also occurs in P. vivax infection. Pathogenesis includes not only lysis due to parasites but also due to some immunological mechanisms. Early diagnosis with prompt treatment with heamatimics/blood transfusion is important in prevention of mortality.

Microscopy is still the most commonly used method of diagnosis of malaria which is insensitive, labour intensive and needs skilled personnel for correct diagnosis. A number of other tests have been evaluated for diagnosis. These include QBC, detection of haemozoin, DNA probes and PCR. The latter two tests are very sensitive and highly specific. They can help to detect low parasitaemias and also can differentiate between species of plasmodia. The major drawback is the coast, as expensive reagents are required. Two tests which have proved to be simple, fast and economical are the parasite F and ICT tests, though these only detect P. falciparum infection. The new optimal ICT is promising in this direction. The need of the hour is to develop a simple, economical and sensitive (specific) test for the diagnosis of malaria.

An understanding of the cytoadherence mechanisms can provide opportunities for development of newer therapeutic and prophylactic strategies. Parasites have different cytoadherence phenotypes.
Resistance to all known antimalarials has been observed. Recently, L B-arte-ether has been tried in clinical trials and found to be effective. This is now available commercially. CDRI-80/53 compound is without acute toxic effects and has low Met Hb toxicity and can be given to G-6 PD deficient individuals for radical treatment. Reversal of drug resistance can occur with nifedipine, chlorpheniramine. CDRI-80/20g has been found useful in Aotus monkeys. There is an urgent need for search for antimalarials from plants/bio-diversity sources in India. Major pharmaceutical companies seem uninterested in development of antimalarials. Incentives by government are essential.

Implementation status of revised malaria control strategy (including Roll Back Malaria) in India
Shiv Lal
National Malaria Eradication Programme
Delhi

Introduction
Malaria is one of the major public health problems in India for a long time and an organized control programme has been in operation since 1953. Throughout its implementation, India experienced a period of tremendous success when estimated 75 million cases and 0.8 million deaths annually were brought down to only 0.1 million cases with no death due to malaria in 1965. This was followed by a period of resurgence with a peak in 1976, registering 6.47 million cases with an increasing trend in P. falciparum proportion. The programme met the challenge by making corrective changes through implementation of Modified Plan of Operation (MPO) in 1977 with more emphasis on early diagnosis and prompt treatment, selective vector control on the basis of area prioritization and health education besides introducing a component of drug sensitivity monitoring in P. falciparum. Implementation of MPO was reinforced by the P. falciparum Containment Programme conducted with cooperation of WHO and assistance from SIDA. These concerted efforts led to success by bringing down the annual incidence to less than 2 million cases in 1985 which continued upto 1988. However, since 1989 there has been a gradual increase in annual malaria incidence which is fluctuating around 2-3 million cases.

Current Epidemiological Situation

As mentioned above, annual malaria incidence in India has been fluctuating around 2 to 3 million cases with a marginal increasing trend in recorded malaria morbidity till 1996 (Fig. I). However, the data is based on the surveillance through the health care delivery system and does not accound for the cases that report to private sector for medical assistance. There has also been an increasing trend in P. falciparum cases proportion and spread of drug resistance in P. falciparum. The mortality trend showed a marginal increase till 1993 and from 1994 a sharp increase in registration of deaths due to malaria has been evidenced mainly because of a policy change in the programme when it was decided to include the death cases even on clinical suspicion of malaria as a death due to malaria (fever-related deaths).

Fig. 1 : Malaria Trend in India
Malaria outbreaks of local and focal nature have been an inherent feature of epidemiology of malaria in India and there have been an increasing frequency of malaria outbreaks during the last few years particularly during 1994, 1995 and 1996 when such outbreaks became widespread in several states like Assam, Manipur, Nagaland, Maharashtra, Gujrat, Rajasthan and Haryana.
Malaria Control Strategies
Under Modified Plan of Operation, India implemented a three pronged strategy :
1) Early case detection and prompt treatment
2) Vector control by indoor residual insecticide spray in rural areas with Annual Parasite Incidence (API) per thousand population of 2 and above in the preceding three years with appropriate insecticides and by recurrent anti-larval measures in urban area.
3) Health education and community participation.
As has been mentioned, Indian Malaria Control Programme has been making periodic modifications to meet the malaria challenges more effectively in view of increasing morbidity, occurrence of outbreaks, increasing trends in P. falciparum and increasing trends in spread of drug resistant P. falciparum. Though the malaria control programme operating in India had these basic elements as part of the strategy since 1976, the necessity for reiteration of political commitment and reinforced implementation of certain key elements at the operational levels became obvious with adoption of Global Malaria Control Strategy. The programme has made necessary adjustments that envisages four basic elements :