Malaria in India

            Malaria is endemic in all of India except at elevations above 1800 meters and in some coastal areas (Sharma, 1996a).  In most parts of the country, periodic epidemics of malaria occur every five to seven years (Sharma et al., 1994).  Although the total number of cases of malaria in India has stabilized somewhat over the past ten years, there has been an increase in the number of P. falciparum cases (Pattanayak et al., 1994).  65% of malaria infections in India are caused by P. vivax and 35% are caused by P. falciparum (Kabilan, 1997).  P. falciparum malaria has a shorter average incubation phase in the mosquito vector, thus speeding up transmission between people by limiting the time in the interim phase.  P. falciparum also causes the most fatal type of malaria (Pampana, 1969). 

The estimated economic loss due to malaria in India from 1990-1993 is $506.82 million to $630.82 million (Sharma, 1996c).  India has spent up to 25% of its health budget on malaria control from 1977-1997, and starting in 1997, India planned to spend $40 million on malaria control, a 60% increase from the previous year.  This expenditure is part of a five year program aimed to target 100 districts where 80% of all P. falciparum cases occur (Jayaraman, 1997).  70-80% of the malaria control money in India is spent on insecticides (Dhingra et al., 1998).

            India started using DDT to control malaria in 1946.  In 1953, when 70 million cases and 0.8 million deaths occurred due to malaria (NMEP, 1996), the National Malaria Control Program was created.  This program was renamed the National Malaria Eradication Program (NMEP) in 1958 due to the success of DDT and the commitment to malaria eradication in India at that time.  The NMEP believed that it could eradicate malaria in seven to nine years, but malaria began to re-emerge in 1965 (Sharma, 1996a).  After 1965, malaria rates in India rose gradually and consistently with a peak of 6.47 million cases in 1976 (NMEP, 1996).  This resurgence of malaria caused India to begin an attempt to control rather than eradicate malaria in 1977 with the Modified Plan of Operation (MPO) which also comprised the P. falciparum Containment Programme (PfPC).  The PfPC aimed to contain the spread of falciparum malaria, which is the most commonly resistant and most deadly strain of malaria (Satpathy et al., 1997).  During MPO, chloroquine distribution was extended through Fever Treatment Deport and Drug Distribution Centers in addition to the other ways that malaria drugs had already been distributed.  MPO also only used residual insecticides in areas with an API (Annual Parasite Index) above two (Satpathy et al., 1997).  This method still relied mainly on spraying pesticides and distributing anti-malarial drugs, although there was also an attempt to get more local officials involved in anti-malarial activities and an increase in research (Barai et al., 1982).  By 1985, it seemed as though the NMEP would succeed in controlling malaria because there were only 2 million cases of malaria and the incidence rate had stabilized.  India has, however, experienced more epidemics and deaths from malaria in the 1990’s along with the creation of new malaria paradigms (Sharma, 1996a).  In 1994, there were large-scale epidemics of malaria throughout India, and since then malaria mortality has increased (Dhingra et al., 1998).

Malaria Control History in India

Although the total number of cases of malaria has remained relatively constant for the last five years, outbreaks have increased the number of malaria deaths (Dhingra et al., 1998).  P. falciparum cases have also consistently increased from 9.73% of malaria cases in 1977 to 34.5% of cases in 1995 with a peak of 43.3% in 1991 (NMEP, 1996).  In 1995, India implemented a Malaria Action Plan (Satpathy et al., 1997). 

            Resistance to pesticides was first noted in India in 1959.  However, it was only as resistance increased in areal extent and amount, that it started to affect the success of the eradication program.  In the 1960s, because the eradication program was doing so well, malaria research stopped.  Also, as resistance to DDT increased, so did the use of alternative insecticides, which later caused the emergence of vectors resistant to those insecticides.  As of 1996, individuals of An. culicifacies, one of the six most important vectors of malaria in India, had been found resistant to DDT in 18 states and 286 districts, to HCH (hexachlorobenzene) in 16 states and 233 districts, and to malathion in 8 states and 71 districts.  An. stephensi, another important malaria vector in India, was found resistant to DDT in 7 states and 34 districts, to HCH in 6 states and 27 districts and to malathion in 3 states and 8 districts (Sharma, 1996a).  The use of some of the same pesticides in agriculture could have increased the speed with which malaria-transmitting mosquitoes became resistant (Sharma, 1996a).

            Not only does resistance limit the effectiveness of pesticides in malaria control, but pesticide prices are increasing and India only makes 30% of its DDT domestically.  Therefore, pesticides are not an economically unsustainable malaria control technique for India (Sharma, 1996a).  Pesticides are also toxic to humans and the environment.  Currently, 70% of all insecticides in India are DDT and BHC (benzene hexachloride), and their use is increasing at a rate of 6% a year in India.  Both of these pesticides are persistent, and accumulate in soil, water, and biological organisms, and thus were banned in the US.  Due to the increasing use of DDT and BHC in India, food contamination is expected to increase (Pimentel, 1997).  However, the NMEP reports that there has been “no adverse reaction of DDT on human health” (NMEP, 1996).