Frontline Messages (1)

Projects : These have created major problems. The projects are constructed on uninhabited lands; sometimes for cheap cost these are constructed in areas having high malariogenic potential. Innumerable breeding sites are created in construction areas. There is aggregation of workers both from endemic and non-endemic areas resulting in malaria transmission. The magnitude of the problem could be imagined from the fact that in 1951, there were only 5 public enterprises and by 1993, there were 245. In addition to these public enterprises, many private enterprises have come up during the last two decades.

·Migration of population : Large scale population movement takes place for agriculture, construction activities and cattle grazing from endemic to non-endemic areas and vice-versa. This is responsible for the spread of malaria, particularly of resistant P. falciparum.

·Urban malaria : In the eradication era, urban areas were not covered under the programme, on the presumption that anti-mosquito activities were carried out by the local authorities including strict enforcement of by-laws for elimination of vector breeding. But this was not successful. In addition, there was migration of population to urban areas from rural areas for job opportunities. Mostly these are surplus agriculture workers consequent to large scale mechanization of agricultural practices. The aggregation of the migrant population creates a distinct epidemiological zone, know as "periurban area" that is highly malariogenic in the absence of any civic facilities. When malaria declined in the rural areas, urban areas became the epicenter for spread of malaria.

Border problems adding to malaria situation : India has extensive borders with Myanmar, Bangladesh and Nepal. Movement of population, both legal and illegal, and in the absence of any coordinated action, between the neighbouring countries, has resulted in spread of malaria from one neighbouring country to another.

Hard core malaria prone areas : When India reported 0.1 million cases in 1964-65, the bulk of these cases were concentrated in the tribal belts, known as "hard core" areas. In the absence of socio-behavioural studies in these areas, control measures carried out remained less effective. There was spread of malaria from hard core areas to plain areas.

Vector resistance : Repeated insecticide sprays created problem of vector resistance against commonly used insecticides and alternate insecticides were less used because of prohibitive cost.

Microbial resistance : P. falciparum showed resistance initially to chloroquine in North-Eastern states and it spread westwardly. Now in many situations, it is resistant to 2nd and 3rd line of drugs.

Inadequate response from health infrastructure : During 1964-65, there was sudden withdrawal of insecticide supply by the bilateral agency due to political reasons. Procurement of insecticides from alternate sources took considerable time during which focal outbreaks, could not be contained. Considering that malaria had been eradicated, there was large scale diversion of staff to other programmes and many posts remained vacant. Integration of malaria programme into the district health system has not been to the desired level.

Discontinuation of minor engineering methods : In the pre-eradication era, minor engineering methods were of immense value in eliminating vector breeding. This practice was discontinued in the "Insecticide era". No efforts were made to re-introduce these methods when malaria re-emerged.
Paradigms of Prevalent Malaria Situation
Considering the factors for re-emergence of malaria, the prevalent malaria situation has been classified into various paradigms. Classification of paradigms aims to rationalize malaria control activities suitable for each paradigm. Needless to mention that rigid central policy and its implementation, particularly at the most peripheral area is no longer valid, as epidemiology of malaria has and is changing very fast. Malaria being a local and focal disease, flexibility is the key approach. Classification of prevalent malaria situation into various paradigms is essential for undertaking suitable remedial measures. These paradigms might change in future depending upon the prevalent malaria situation then

Malaria Paradigms of Prevalent Malaria Situation Are As Follows :
Tribal Malaria : It can also be sub classified as :
a) Tribal malaria of deep forest and forest fringes
b) Tribal malaria in proximity of forest fringes and with disturbed ecology.

In group (a) An. Dirus, An. Minimus and An. Fluviatilis are common vectors. Because of high perennial transmission of infection, mortality and morbidity among adults are mostly constant. Mortality is high amongst pregnant women and children. P. falciparum is predominant with varying degree of drug resistance. The basic health services and availability of antimalarial drugs are poor. In the absence of any socio-behavioural studies of the mobile tribal population, control measures should primarily aim to reduce mortality and morbidity with easy availability of appropriate drugs.
In group (b), the common vector is An. Philippinesis. Predominant infection is P. falciparum. High mortality is among non-immune persons. Control measures should be directed for prevention of mortality and morbidity, control of epidemics, and reduction in the transmission of resistant P. falciparum.

Rural Malaria : This can be sub-classified as :
(a) Irrigated arid zones
(b) Areas without irrigation.

In group (a) P. vivax is predominant in lean season and epidemics occur with P. falciparum. The endemicity ranges from moderate to low. There is localized P. falciparum resistance. An. Culicifacies is the common vector. Health services are moderately available. Control measures should aim to prevent and control epidemics, reduce morbidity and reduction in the transmission of resistant P. falciparum.
In group (b) endemnicity is low. P. vivax is predominant. During epidemics, P. falciparum is predominant. An. Culicifacies is the common vector. In rural desert areas An. Stephensi has been reported. Health services are fairly well incidence of malaria, prevent and control epidemics.

Project Malaria : The ecosystem is disturbed leading to epidemicproness. There may be more than one vector operating. Health facilities at the project sites are limited. With large aggregation of labour population from endemic areas, spread of resistant P. falciparum is high. Control programme should be directed for prevention of mortality, reduction in morbidity and control of infection transmission, particularly of P. falciparum.
Border Malaria : There is frequent mixing of population and consequent transmission to interior of the country. More than one vector operates in these areas. Health services are very thin and communication with the neighbouring countries is poor. Control programmes should promote co-ordinated action with the neighbouring countries.

Migration Malaria : Migration of population takes place from non-endemic to endemic areas and vice-versa. This paradigm cuts across all epidemiological types and is more pronounced in project areas. Localised epidemics are common. Control measures differ according to site of aggregation of population. The objective of control programme should be prevention and reduction of mortality. Transmission control in project areas needs to be promoted.

Urban Malaria : There are two distinctive features, namely, urban and peri-urban areas. In the urban areas, An. Stephensi is the vector, while in peri-urban areas, An. Culicifacies is the predominant vector. P. vivax is the most prevalent infection. Epidemics with P. falciparum have been reported from peri-urban areas. Enforcement of by laws for prevention and elimination of breeding places should be the key approach with strong anti-larval measures in urban areas. In peri-urban areas, transmission control and reduction of morbidity should be the objective of the control programme.

Malaria paradigms identified for undertaking better control measures would need strong research support in the area of :
Health system research : To locate the deficiencies and optimize integration of malaria programme particularly prompt diagnosis, treatment and surveillance for early detection and prompt containment of epidemics.

Research to prevent the spread of resistant P. falciparum

To develop mechanisms for active community participation particularly for promotion of health seeking behaviour

To reduce man-mosquito contract through cost-effective, safe and user friendly protection methods

Operational studies to promote the concept and practice of microepidemiology as malaria is a local/focal disease.

Cost effective vector control measures in old and new irrigation zones and project areas

Studies to demonstrate and integrate the "forgotten practice of minor engineering" into Malaria Control Programme

Studies on sustainable bio-environmental methods within the existing health infrastructure.

Bibliography
1) Pattanayak, S., Sharma, V.P. Kalra, N. L. Orlov, V. S. , Sharma, R. S., : Ind Jour Malariol 1994; 31.
2) Sharma, G. K. (1983) Review of malaria and its control in India : Proceeding of Indo-US workshop on malaria
3) Pattanayak, S., Roy, R. G. , Samnotra, K.G., Bendlay, M. S. : Ind Jour Malariol 1981; 18(1)
4) Kalra, N. L., Sharma, G. K. Jour Com Dis 1987; 19,91-116
5) Clyde, D., (1931) : Records Mal Surv Ind 1931; 2,1
6) Kalra, N. L. World Bank Mission Report 1994, New Delhi
7) Kondrashin, A. V. Forest Malaria in South East Asia, Eds. New Delhi, 1-28