Malaria resurgence in India: A critical study

Sot. Sci. .Med

Vol. 22, No. 8. pp. 835-845. 1986

01774336

86 S3.M fO.00

PergamonPressLtd

Printed in Great Bnrain

MALARIA

RESURGENCE

IN INDIA:

A CRITICAL

STUDY

V. P. SHARMA’and K. N. IMEHROTRA’ ‘Malaria Research

Centre,

22-Sham Nath Marg, Delhi-l 10054 and ‘Indian Institute, Pusa Road, New Delhi, India

Agricultural

Research

Abstract-In 1953, the Indian National Malaria Control Programme (NMCP) was started. Encouraged by the results, and the fact that insecticide resistance in vector species may evolve and become an obstacle. in 1958 a control programme was converted to the National Malaria Eradication Programme (NMEP). By 1964, malaria was eradicated from 88% of the area and it was in the advanced stage of spraying in the remaining parts. At that time, focal outbreaks that occurred in 1965 and increased in later years. could not be contained due to the shortages of DDT. As a result, large areas in consolidation and maintenance phases were reverted to the attack phase. Besides, the infrastructure in general health services was not adequate and mature enough to take up surveillance and vigilance. This produced a large number of secondary cases due to the re-introduction and relapse of malaria. Added to this was the problem of urban malaria, the control of which was the responsibility of local bodies. Malaria cases increased in towns, and started diffusing to the rural areas, due to inadequate staff and the shortages of malarial larvicidal oil (MLO). Later, it turned out, that while it was technically feasible to eradicate malaria from 91% of the population, the strategy of indoor spraying of DDT to interrupt transmission did not succeed in 9.O?b of the population, despite more than 12-14 years of regular spraying. During the years of resurgence, there was no research support to the programme, so that technical problems were not properly appreciated. understood and tackled. The reservoir of parasites that were present throughout the country started multiplying and spreading to newer areas due to the presence of vectors in high densities. Thus malaria resurged and re-established itself even in areas that were at one time freed from the disease. The analysis of the pattern of malaria resurgence revealed that malaria outbreaks preceded the true problem of insecticide resistance. It is noteworthy to mention that malaria resurgence occurred in towns where the control measures were non-insecticidal and in regions which were not under the influence of insecticide-resistant vectors. The study also revealed that resurgence occurred before the introduction of high-yielding varieties programme in the country, and had no relationship to either the cotton or rice growing or intensive agriculture.

INTRODUCTION

Before malaria control was undertaken in the country, it was estimated that nearly 100 million people suffered from the disease and 800,000 people died annually. This figure was considerably higher in the epidemic years. Also large tracts of fertile land remained uncultivated due to the ravages of malaria. The health survey and development committees of the Government of India in 1946 recommended that anti-malaria organizations might be established in the States and these be linked with a central organization. Between 1946 and 1953 several States, in close collaboration with the erstwhile Malaria Institute of India, had undertaken large-scale successful anti-malaria programmes with indoor residual spray of DDT in rural areas. Simultaneously, four WHO demonstration teams took up pilot projects for control of malaria in different parts of India under different ecological conditions. Encouraged by the results of these studies, the Government of India, in 1953, launched the National Malaria Control Programme (NMCP). As a result, about 166 million population was protected from malaria and the overall reduction in the epidemiological indices by the end of 1957-1958 ranged from 63 to 79%. Between 1953-1957 the ratio of malaria cases to total sickness was reduced to about 60% (from 10.8 to 4.4) and the child parasite rate and child spleen rate was reduced from 3.9 to 0.8 and 15.7 to 4.2 respectively [ 11. s.s M 2? S-o

835

At that time, national and international scientists expressed the view that insecticide resistance may become an obstacle in the foreseeable future. and also the fact that the control programme would have to be continued indefinitely, therefore, the control programme should be converted to that of eradication. This view was accepted by the Government of India, U.S. AID and the WHO, and the control proaramme was converted to the National Malaria Eradication Programme (NMEP) in 1958. Results under SMEP were so spectacular that the incidence of malaria was drastically reduced to about 100,000 cases in 1965, and there were no deaths due to malaria. This followed a period of resurgence, which occurred in the late 1960s and continued unabated (Table 1). Realizing the seriousness of the situation, and considering the constraints, the Government of India implemented the modified plan of operations in 1977, thus converting the eradication programme to that of control and containment [2, 31. Because of the drastic reduction in malaria incidence, it is generally believed that malaria was eradicated from India and resurgence was the result of inter aliu insecticide resistance in the vector species. In a recent study, Chapin and Wasserstrom [4,5] proposed that “resurgence of malaria in Central America and India seems to have been parallel by intensified agriculture in these countries and the associated increased use of pesticides”. In subsequent correspondence to ‘Vuture, this paper was the subject of criticism [6-l I]. In their final letter to ~Vurure.they

Slates

’

“..

Sourw:

I’JOI

I’JGX

Andhra Pradesh ASWIll flihar Gujaral Hil~y~ll~ Himachal Pradesh Jammu nnd Kashmir K;wn;~mk;l KW;ll;l Madhyit I’ralesh MLlhWUht~~ Manipur Meghalaya Nagahmd Orissa Punjab Rajasthan Tamil Nadu Tripura lJ1tar Pmdrsh Wrsl l+agal A~~daman and N&bar Arumichal Pradesh Chandigarh Coallields Delhi DNK Projects C
NMEI’;

Year

45

3

l’J6LJ

M;tdlwh

59575

333 276

709 40

I’)76

II758 966 3210 1412 140 3525 I57 502 153

I7 5052 1478 8494 2061 41 3117 I60 495 277

4’JlSl

I335 65 X609 4496 54

7 5

16 IO 3650 III 11x0 3641 95

1962

12533 3203 3505 32X6

1961

8904 2112 3444 4044

lY63

1964

335 I9

I75

142 -

II7 61

II5

68

c‘ommiltcc

1131

I I2942

-

317Y6 532 3164 896 8011 4126 860 461 II90

I7376 570 3x13 3091 55Y 5194 472 I308 143X

X7306

43 7 780 33 137x1 4998 93

1124X III43 4647 21656

43 2 646 55 X’J20 3570 102

I3962 10677 4556 10571

x9 518 1001X5

35

25 7

26 24’J92 334 2872 563 831 3365 273 442 801

x I570 67 20157 6095 270

I21

9400 10484 1513 I5321

1965

37 144 14x150

3

53 45

409 9949 332 96X0 265 1825 10222 425 I20 1008

4704 I2744 I824 17170 155 15 5 11x2 124 62357 12X90 409

1966

25 407 27X62 I

II

IX8 II4

266 IX561 IX36 23X9X IX3 3861 1229X I Y96 927 3644

2918 17215 3111 19652 2219 50 29 x5x I43 X456’) 19410 173

1961

34 247 274xx I

9

325 31794 9503 I4999 356 7507 6649 24hO I x74 5816 5 390 37

I I029 13.5 66460 26785 460

7658 21610 6007 56005 6610 II6

1968

I

I9 672 34X647

6

414 243

X22 2XY62 II220 154x7 761 7369 3785 692 I x74 I0798

X765 276Xx X057 91744 XX7 I 71 I 140x 202 577X6 60350 579

I969

Table I. Malaria cases in India 1970

1971

34 720 132311X

3436

3796 29 630 hY4647

32

464 3852

21652 I7434 I2447 SK33IO 24523 x3 4 37725 287 191236 199096 310 2751 435 33260 51372 I09773 1557 2772 989 I 965 1753 II944

12

236 1056

602 1138X I5886 79788 I300 4247 7719 423 2YX9 746 I

2411 27’) 13310x 91319 498

I3334 17219 9876 26930 I 13x97 x7

1972

77 1376 1430025

2573

IO4

50482 17246 I6701 524914 49126 236 34 41523 41J4 215264 223289 843 2934 875 51226 99082 X2517 isin 6579 I7676 363X 3060 l226Y I7 864 357x

1973

I96 4212 l’J344X5

x640

I24

94400 3791X 3Y9X9 437292 lOY777 IO92 1036 7x443 060 276910 262780 2147 6393 2823 189167 I66346 IIXOl2 5n69 5171 52052 I2433 I519 IO657 917 3452 3452

1974

inn 5208 3 172X66

6912

I65

I342Y5 58478 Xl’)03 S73l IX 22986’) X076 361X I73044 X62 477058 428432 I342 4107 310x 2Y770 I 230252 177597 19657 3562 193715 193x7 1118 2227 I 2373 3228 12163

1975

5160142

1317Y I74 I34

I51 I03 I26362 Y437l 7YYIXO 507220 l64XI I’)403 33O’JfLl 1651 X366X0 705472 2162 6763 5344 3 1766’) 288214 354567 7457’) x002 3K I750 39634 II06 24810 4269 3n94 3737Y 124’13 634

lY76

<

64672IS

27’J34 IO535 4266 4Y330 I5465 2012 103 I lY4l 325 II3

6

g

z

;

4 I2776 IO392 I 7171 33772X 2X!,1510I7

E

5

;

?

I WJ 32’) 104 440465

210154 I4XbOX 7X04X I2 I4iJ2X 736Sh6 221 IO 37x.19 0.14517 SOL’) X7XOY3 702155 120x 7035

Malaria resurgence in India: a critical study

837

Table 2. DDT required and received by the NMCP N.MEP for malaria control in India DDT (75% WP) in metric tonnes Received Year 1963-1964 1964-1965 1965-1966 1964-1967 1967-1968 1968-1969 196Sl970

1970-1971 1971-1972 1972-1973

I a200 14510

I4100 9350 a950 13148 IS900 14806 14170 14170

Shortfall

Imoorted

Indigenous

Total

Quantity

%

14627 lo815 7390 3940 4060 as00 a535 5807 7000 5712

3763 3642 2258 2728 3700 2933 4570 5407 4426 3666

18390 14457 9648 6683 7760 II433 13105 II214 II426 9378

0 0 4452 2682 II90 1715 2795 3592 2744 4792

31.6 28.9 13.3 13.1 17.6 24.3 19.4 33.8

Source: Madhok Committee [13]; in-depth evaluation 1970 and 1974 [l4. 151

stated that the criticism did not change any of their contentions [12], and also that they have not been able to get the account of happenings after 1965-1966 1151. We have, therefore, made a study of the resurgence of malaria in India. The study is based mainly on several reports of the National Malaria Eradication Programme’s (NMEP) evaluation [I, 2, 13171. SHORTAGE

NMEP’s 30% requirement of DDT of about 4000 tons was produced indigenously. Due to power cuts and other reasons, production fell below the NMEP’s requirement. Also, whatever quantity of DDT was received, it was not supplied at one time for spraying, instead it was received in small quantities throughout the year. As regards imported DDT there were delays of up to 15 months in processing of the initial request. In 1965-1966, an additional quantity of 3000 tons DDT was required as a result of rephasing but could not be procured for want of foreign exchange. In the same year, indigenous supply fell short by 1452 tons. In 19661967, an additional requirement of 1700 tons imported DDT was received late, and the indigenous supply also fell short by 982 tons. It was only in 1967-1968 that the shortage of 1190 tons was made up from the carried stocks. Again in 1968-1969 supplies were short and it was possible to supply DDT to the States for the first round and not for the second (131. During 1969-1970 and 1970-1971, 3000 and 750 tons of technical grade (100%) DDT was imported from the United States to be formulated in India. For various reasons 500 tons DDT (50% WP) could be formulated in the 2-year time and the balance was stored [14]. The shortage of insecticide continued in the subsequent years (see Table 2). The shortage and interrupted supply of DDT resulted in setbacks to the programme. The small focal outbreaks started in 1965 in consolidation and maintenance areas, These outbreaks increased in

OF DDT

The study revealed that one of the serious and continuing impediments to the success of the NMEP was the irregular and interrupted supply of DDT to the units (Table 2). DDT was the principal insecticide used for the residual spraying of houses to interrupt transmission. From 1958 to 1964, the success of malaria control was so notable that India became a showpiece for the world. Adequate supply of insecticide and equipment was made available to the programme under the U.S. AID until 1962-1963 with simultaneous development of indigenous DDT (50% WP) production in Alwayne and Delhi. As a result, as much as 88% of the area was in consolidation and maintenance phases and only 12% area (i.e. 44 units out of 393.25 units) remained in the attack phase. U.S. AID supplies were stopped in 1963 and from 1964 onwards the Government of India purchased the insecticide from the United States under a U.S. AID non-project long-term loan-agreement [2].

Table 3. Reversion of units to attack phase S. No.

I. 2. 3. 4. 5. 6. 7. a. 9. IO. II.

state Assam Bihar Gujarat Haryana Madhya Pradesh Maharashtra Mysore OliSSa Punjab Uttar Pradesh Rajasthan

1965-1966. cons. 0.25 3.00 3.00 0.25 0.95 1.00 0.75 0.75 1.64

19661967*

l967-l968*

Cons.

Cons.

-

-

Il.59

196&1969* Cons.

0.75

I .73 II.75 3.19 0.90 0.20 3.93 2.25

I .57 2.625 13.02 0.06 IS.24 6.19 0.20 0.25 5.94 6.69

16.66

23.95

51.785

-

0.25 7.07 0.75 4.00 0.25 0.95 I .OO 1.64

*Temporary reversions made on ad hoc basis. During 1963 and 1964, focal outbreaks occurred in Consolidation 2 million and were tackled by routine remedial measures [I]. Source: Madhok Committee [13].

Maintenance

2.12 0.77 2.00 -

1.62 a.50 4.59 19.60

phase areas involving a population

of

838

V.

Table

P. SHAR~Uand K. N. 4. Spray

rounds

missed

MEH~OTRA

or extended

in tmx

Circumstance Spray

rounds

reported

Seither Number “*its

nor Missed

Extended

extended

-

Labour problems

9

1

Nagaland Union Tetitories

I 6

I

I -

2

2

3

3

2

IO

1

9

0

7

UttarPradesh

3

2

3

3

5

Rajasthan

7

7

7

0

5

Bihar Madhya

Pradesh

Assam Andhra

Pradesh

Maharashtra

6

3

4

2

2

16

16

9

0

3

I2

4

and

2

5

4

1

2

6

2

5

I

4

1

-

4

0

-

I

Kashmir

Total

96

‘Considerable Missed:

amount

of data

Since commencement

I -

-

2

-

-

-

-

51

32

21

31

I3

8 (89%) -

(0%)

?(33”;)

z

Y (SO%)

4

4 (57%)

5 (63%)

-

?(33%Y

-

15 (94?b)

-

7 (58%)

-

J (66%)

-

2

-

of

DDT

5 [56O 0)

-

-

non

arrival

I -

-

4

I

Jammu

2

Delay

water

1

:

4

of

-

-

4

Mysore Bengal

-

9

West

or lack

f;utlS

3

mlssed

Drought

heavy

-

wth

rounds

Or

Gujarat

Orissa

as assoclared

Floods

missed

of state

reported

or extended

as

-

- (096) 3 (7%)

7

- (0%) 63 (66%)

lacking. of NMEP.

Extended:

during 1967-1969. Source: in-depth evaluation. 1970 1141.

subsequent years. As a result, a large number of operational units were temporarily reverted to spraying as shown in Table 3. During 1966, 33, 48, 32 and 22% of the unit areas in the states of Assam, Orissa, Madhya Pradesh and Gujarat were still in the attack phase. The large-scale focal outbreaks reported during 1966 were in 13 states in consolidation units involving 32 million population. These occurred mainly in the states of Gujarat, Madhya Pradesh, Maharashtra, Uttar Pradesh, Bihar and Rajasthan which accounted for 92% of the total population involved. Owing to untimely and short supply of insecticides in most of the consolidation areas with focal outbreaks, insecticidal protective coverage was not possible during 1966. The factors that contributed to the short supply of DDT were the outbreaks of hostilities with Pakistan and a breakdown in production at the Alwayne Factory. Focal outbreaks extended further during 1967-1968; out of the total of 23.95 unit areas reverted to the attack phase, about 95% unit areas were in Gujarat, Madhya Pradesh, Maharashtra, Rajasthan and Uttar Pradesh. Although formally designated as consolidation phase areas, the areas of focal outbreaks were treated as temporarily reverted to attack phase with resumption of spray operations. The number of such reverted unit areas was about 12, 17 and 24 in the year 1965, 1966 and 1967, respectively. These reversions were resorted to on an ad hoc basis in areas with appreciably large numbers of cases. In 1968, a uniform criterion of 200 cases per million population was laid down for the reversion of unit areas to attack with resumption of spray operations [13].

In 19681969, units temporarily reverted to attack phase. on an ad hoc basis, were formally recognized as attack units. It may be pointed out that out of the 71.385 units reverted to spraying till 1968196951.785 from the consolidation phase and 19.60 from the maintenance phase-59.215 units or about 83% of the total were in the hyper-endemic areas and 12.17 units of 17% were in the hypo-endemic areas, that 47.72 of these units were carried over from the control programme. while 23.665 units were under the eradication programme. It was obvious that along with shortages of DDT, suneillance was inadequate and measures to deal with the outbreaks were tardy and deficient. A study of the missed or extended spray rounds of 96 units* in persistent attack phase revealed that 75 units (78%) reported either missing or extended rounds or both (Table 4). The states most notably affected were Madhya Pradesh (15 out of 16), Gujarat (8 out of 9) and Orissa (8 out of 10). During 1967-1969 coverage of less than 90% was achieved in 68 (7 1%) of the 96 units with persistent attack phase. In another 10 (lo%), the information was either absent or of such a nature that no decision could be made on coverage [14]. It would be seen from the data shown in Tables 2, 3 and 4 that the main reason for reversion was the shortage of DDT. Thus the Madhok Committee [13] stated that “The three factors working together viz. (a) late receipt of supply from U.S.A., (b) inadequate supply from indigenous sources and (c) short supply arising from inability to import timely additional requirement on the basis of actual phasing of the programme has been partly responsible for a setback to the programme particularly since 196.5-1966”.

*A unit was an administrative

entity intended to cover on an average I.0 million population. As a result of population increase, the unit covered 1.3 million population. The geographical area allotted to a unit was expressed as I.0 and parts, expressed as proportions such as 0.5, 0.8 etc., of the unit area. As an example the areas in persistent attack were geographically located in 96 units, but the total unit area was 39.38 [14].

URBAN

YALARIA

During the initial planning of malaria eradication, urban areas were not included in the eradication programme. Cities and towns with a population of 40,000 or more were considered either hypo-endemic or malaria-free. In 1961, there were 310 cities and

Malaria

resurgence

Table 5. Diagnosed

in India: a critical study

cases of urban and rural malaria

Year

Urban cases

Rural cases

Total

I968 I969 1970 (Till Scot.)

0.956 I I.46 I x.214

47.013

55.969 92.339 90,996

Source: in-depth

evaluat~oo,

90,578 68.782

with a population of 79 million which steadily increased to 100 million by 1967. Malaria control in these towns was the responsibility of the local bodies like municipalities, corporations, etc. The local bodies were often under-staffed, inadequately financed and most importantly suffered from the lack of qualified persons. Therefore, these bodies also lacked accurate knouledge of the total breeding potential [I, 131.In urban areas the principal malaria vectors are A. stephensi and A. culicijhcies. The magnitude of the problem could be understood by the fact that, in 1969. a study in Cambay city, Gujarat State had shown that A. srephensi was breeding in 613 welldefined places like the used and unused wells, cisterns and overhead tanks; but there were 9514 (15 times more) smaller breeding sites. Similarly in Hyderabad city. the records showed that in some localities, with effective weekly anti-larval measures, 80% of the time. overhead tanks were positive with the first and second instar larvae [14]. Malaria control in urban areas required careful study and intensive anti-vector measures which were lacking. As a result, while transmission was being interrupted in rural areas, it remained uninterrupted in big cities resulting in severe outbreaks of malaria in 1961 and 1962 in certain major towns of Andhra Pradesh and subsequently in Madras. In 1963, out of 87.306 confirmed malaria cases 9750 (11.2%) cases were reported from 10 municipal towns in Andhra Pradesh and Xfadras. During 1964, out of 112,942 cases, 10 municipal towns with A. stephensi problem contributed 8089 (7.2%) cases. In Gujarat all the urban localities had malaria and a comparison of cases diagnosed in all urban and all rural areas in Gujarat for the 3-year period showed (Table 5) considerable increase in urban malaria cases [14]. There were shortages of the mosquito larvicidal oil @iLO). Under the National Filaria Control Programme (NFCP) and Urban Malaria Control Malaria cases recorded in urban areas of Tamil Nadu as compared to total cases recorded in the State

Year

Total malaria cases in Tamil Nadu

Cases from urban areas only numbers

%

1961 1962 I963 1964 1965 I966 1967 I968 1969 1970 1971 1972

1674 1414 3752 I596 594 263 IS3 355 761 1099 I550 1179

a41 919 3555 1436 543 238 I61 I74 252 975 387 603

50.2 64.9 94.1 89.9 91.4 90.5 87.9 49.0 33.1 88.7 24.9 51.1

10084

69.9

Total Source:

I4420 Roy PI al. [IS].

in Gujarat Crban

cases (O.1 16.0 12.5 2J.3

1970 [II].

tounj

Table 6.

839

Scheme of the NMEP, the attack on the aquatic stages of the mosquitoes mainly used MLO. The Assessment Committee of the NMCP (1971) highlighted that the breakdown in the supplies of ML0 from 1967 onwards was responsible for breakdown in the anti-larval operations resulting in considerable increase in mosquito density indices and the efforts made during the previous years became more or less infructuous [ 161. A study of the urban malaria problem in Tamil Nadu State revealed that in 1961, nearly 50% of the cases detected were from the urban areas and the proportion increased to 95% in 1963. Between 1964-1967, urban malaria accounted for about 80% of the cases. There was some improvement in the subsequent years except in 1970 when 88.7% cases were recorded from urban areas (Table 6). The majority of the cases were indigenous, and even the imported cases (25-30%) came from other towns with an urban malaria problem [17]. The proportion of urban malaria cases have remained at about 50% since 1972 [18]. It was also estimated that 25% of the total detected urban malaria cases were exported to rural areas before the drug treatment was complete [14]. It was therefore obvious from the epidemiological data available that while the incidence of malaria in rural areas went down considerably, the malaria incidence in urban areas in the state of Andhra Pradesh, Tamil Nadu, Maharashtra, Gujarat and Rajasthan had started showing an increase due to the developmental activities in the urban areas, attracting rural population as labour, and malaria transmission flourished resulting in the establishment of the foci of infection. These foci disseminated infection again to the rural population due to movement of labour. Thus, the 1970 in-depth evaluation stated that the exclusion of urban malaria from NMEP was the most important omission in the eradication programme [l4]. SURVEILLANCE AND GENERAL HEALTH SERVICES

The eradication of malaria was possible if after the elimination of transmission, surveillance introduced in the consolidation phase was able to detect the remaining cases (100 cases or less per million population) for radical treatment and succeed in the elimination of the disease. Further the vigilance would be so organized under the general health services that any new cases of re-introduction or relapse would be promptly detected and treated. In many areas surveillance was not fully staffed, trained, motivated and adequately supervised or organized in time and laboratory services were poor, and the general health services in many states were not mature to undertake vigilance in the maintenance

V. P. SHARMA and Table 7. Case detection

K. N. MEHROTRA during

No. collected million Unit areas

Year 1964 1965

68.75 170 237 259

S8.76 142.63 196.2s 208.03

I966 ._ I967 Source:

Population in million

Madhok

Committee

report

Year

Nos positive

1961 1962 I963 1964 1965 I966 1967 1968 1969 I970 1971 1972 1973 I974 197s

49151 54454 73008 83664 68132 59306 121069 235759 2998 IO 599809 1093250 1084494 1196724 1778900 2775856

Annual blood examination rate

Passive

Total

Active

Passive

Total

0.13 2.94 6.34 8.21

0.17 I .S8 3.25 3.50

0.30 4.52 9.S9 Il.71

0.27 1.73 2.67 3.6

0.36 0.93 I .37 1.35

0.4 ‘4 ;:S 4.4

1131.

words, the map of reverted areas can be superimposed on those with delays or imperfections in the development of the rural health structure”. INSECTICIDE

phase

RF.SlSTANCE

Although DDT resistance in A. arficifacies was first detected in 1960 in Gujarat, this did not hamper the progress of the programme until 1966 when DDT resistance posed problems in parts of Gujarat and Maharashtra, and during this period large numbers of operational units were being reverted to spraying in other States where DDT resistance was not the problem (see Table 3). In 1970, out of the 44 units scattered in 7 states, ,+l. culicifacies was resistant to DDT in 35 units and to DDT and BHC in 5 units [15]. By 1974, resistance in A. culicifacies was widespread. Resistance tests carried out in 11 states in 143 units revealed DDT resistance in 105 units and DDT plus BHC resistance in 20 units [2] as shown in Table 9. It is, however, important to mention that initially when it was confirmed that the degree of physiological resistance to DDT was high, the change over to BHC was effective. By 1970, in certain areas where DDT plus BHC resistance was high, malathion was introduced. Therefore, although insecticide resistance did pose a problem, replacement insecticides were being used to tackle this. It may also be noted from the data presented in Table 3 that throughout the period of resurgence, focal outbreaks and localized epidemics preceded the evolution of resistance in the field. Resurgence of malaria could not be contained in these areas mainly because of the want of in-

phases of the eradication programme maintenance areas

Consolidation Attack

phase

in

Active

phase [2, 14, IS]. As an example, the annual blood examination rate (ABER) should be at least 10% of the population to ensure reasonable vigilance. During the maintenance phase from 1964 to 1967, ABER was extremely low (Table 7) and this continued during the subsequent years. Vigilance under the general health services was the sheet anchor in preventing the reestablishment of the disease, and this was tardy and deficient. As a result there was an increasing trend in malaria cases in the consolidation and maintenance phases. Initially, the API in maintenance areas increased hundred-fold each year (Table 8). In 1975, 28% of the total malaria cases were recorded from the maintenance phase [19]. The backlog of slides prevented timely administration of radical treatment. As an example, the backlog of unexamined slides for the 20 units in Gujarat was 211,702 on 30 September 1970, and for the 9 units under persistent attack phase, the number was 98,690. There were intervals of up to 4 months in the radical treatment [14]. As a result even during the period of achievements (1961-1965) the trend of the incidence in the consolidation and maintenance phases was on the increase (Table 8). Thus the 1970 in-depth evaluation [14] stated “Therefore, the projection of units for entry into maintenance in areas where the health infrastructure was not adequately established or developed was the tactical error. In fact, we can see that in those States where the rural health services are well developed, such as Mysore and Kerala, reversions have not occurred, and maintenance is kept under good control even in areas previously hyperendemic. In other Table 8. Incidence of malaria in India in different

maintenance

Maintenance

and changes in the annual parasite incidence in the

phav

phase Total % of the positives

Nos positive

% of the total positive

100 97.4 83.6 74. I 68.0 40.0 43.5 85.8 86.0 86.3 82.6 75.8 61.8 56.0 53.7

5121 14308 29232 31492 85223 144719 22388 28829 50151 86683 151093 343453 623803 939087

8.6 16.4 25.9 31.4 57.5 51.9 8.1 8.3 7.3 6.7 10.6 17.8 19.7 18.2

Source: Malaria in India through the years [17). Analysis of API in maintenance phase, personal communication,

Nos positive -46 561 3627 12833 16734 20008 44681 I41 184 194438 394308 770163 1451199

% of the total positive 0.04 0.6 2.S 4.6 6.1 5.7 6.4 10.7 13.6 20.4 24.3 28. I

Dr G. K. Sharma.

Total positive

API in maintenance

CaScS

areaS

49151 5957s 87306 I I2942 lOOl8S 148156 278621 27488 1 348647 694647 1323118 1430025 1934485 3 I72866 5166142

O.OW98 0.0033 0.015 0.05 0.067 0.076 0.165 0.452 0.604 1.224 2.299 -

% Increase in API over the previous year 236.73 354.5s 233.33 34.00 13.43 117.11 173.94 33.63 102.65 87.83 -

Malaria resurgence in India: a critical study

the exclusive influence of A. stephensi as shown in Table 10. Although resistance was reported in A. annularis, but it is a vector of secondary importance and there were only isolated reports of resistance in A. fluviatilis. There was no evidence of resistance in other important vectors like A. minimus, A. bafabacensis, A. philippinensis and A. sundaicus [l, 21-241. The primary and secondary vectors of malaria in different states and union territories [25] are shown in Table 11. It would be seen that vectors responsible for malaria transmission, in most of these regions, did not develop resistance to insecticides [21-231 and malaria resurged with equal vengeance in these areas (see Table 1). An analysis of the areas under persistent attack phase revealed that residual spraying of insecticides was not effective even in areas which were not under the influence of A. culicifacies (Table 12). The spraying in these areas did not improve the situation since the commencement of the programme. There were large parts of the country like the northeastern States where resurgence was not linked with resistance but with exophily and exophagic behaviour of the vector species (1, 1.51. It is, therefore, clear that the insecticide resistance was not the obstacle when resurgence occurred.

Table 9. A. cz/cifacies: summary of insecticide susceptibility tests

Unitsshowing Total

State

units

(till 1970) Bihar Gujarat Madhya Pradesh Maharashrra Orissa Rajasthan Uttar Pradesh

6 9 16 6 IO 7 8

Total

62

(till 1974) Bihar Gujarat Haryana Karnataka Madhya Pradesh Maharashtra Orissa Punjab Rajasthan Tax-nil Nadu Uttar Pradesh

42.00 19.50 6.50 19.13 29.00 33.00 15.00 10.00 16.67 31.45 67.00

Total

Units tested

DDT

DDT -t BHC

resistance

resistance tested

Not

f II 5

Not tested 0

Not tested Not tested 35

289.25

a

Not tested 4

19 2 10 26 26

0

0 0

16 0 0

a

Not tested 0 0

143

IO5

20

Source: in-depth evaluation, 1970 [I41 and 1974 (151.

secticides rather than their failure (Tables 2 and 4). It may be pertinent to mention that the Madhok Committee [13] observed that “The appearance of resistance as indicated by the standard WHO test is not an indication of total failure of the insecticide in interrupting transmission. By ensuring thorough coverage and increasing the frequency of spraying in areas where the resistance in A. culicifacies was noted it was possible to check transmission”. Recently it was demonstrated that spraying of DDT at 1 g/m2 in about 80% of the houses significantly reduced the vector densities of DDT resistant A. culicifacies and the slide positivity rate [20]. Similarly A. stephensi, the vector of urban malaria which was found resistant to DDT and BHC, the control measures adopted in urban areas were not insecticidal but mainly oiling, treatment of wells with aviation gas lead-free (AGLF), Paris green and biological control by fish [13]. Still, malaria cases increased in towns under

OTHER FACTORS

It is noteworthy that apart from 71.385 operational units which were reverted to spraying from the consolidation or maintenance phases by 1968-l 969 (see Table 3), there were 41.60 units which never moved out of the attack phase since the commencement of NMEP. These units were in hyper-endemic areas distributed over 20 states and union territories [13]. Thus the 1970 in-depth evaluation concluded that while eradication was feasible in 91% of the population living in previously malarious areas, there remains 9% of the population (48 million) living in hard core areas where attack operations continued for up to 12 years [ 141.The strategy of indoor residual spraying of DDT did not succeed in these areas and malaria foci were left all over the country. Also, there

Table 10. Malaria cases in A. S. No.

I.

2.

3.

4.

841

stephensi

areas

State/Units

1967

No. of positive cases 1968 ‘1969 1970

Andhra Pradesh Hyderabad and Secundrabad Guntur Vijayawada Visakhapatnam

130 29 131 4

109 40 220 17

350 66 136 31

322 I67 130 21

291 490 205 IO

86 21 2s

47 6 34 a3

28 IO 7 121

33 4 3 93

23 3 I II

1608 4052 196

79 4579 608

343 I 3092 a3

482 12812 11113

2717 I3743 29454

Madras Salem Erode Bhawani Rasipuram Gujarac Broach Ahmedabad Baroda West Bengal Calcutta Total

Source: Malaria in India through the years [l7].

ia

1527

832

120

I26

7830

6654

7475

25306

1971

45 25993

V. P. SHX+MA and K. N. MEHROTR\ Table I I. Principal and secondary vectors of malaria in different Statequnion transmission

territories and the season of malaria Malaria vectors

State,union territory 2.

Andaman and Nicobar Islands Andhra Pradesh

Season of malaria transrmssion

A. sundaicus A. /7uciarilis

Plains

A. A. A. A. A. A. A. A. A. A. A. A. A. A. A. A.

August-March 3.

Arunachal Pradesh (NEFA)

Perennial

4.

Assam-

Perennial

5.

Bihar

Foothills

Perennial Plains 6. 7.

8.

Delhi GWd Gujarat

July-November July-October Perennial Hills and forest

wtws

Secondarv

Princioal

May-October Agency wacu Perennial

culicifocies srephenri sundaicus minimus balabacensis minimus balabacensis philippinensis ~u~+ari/is minimus COIUII(I culicifacies philippinensis culicifacies jhaiarilis Jluriorilir

A. bolabocensis A.

L’~WUI

A. annularis A. stephensi

Perennial A. culicifacies A. stephensi

Pllli?lS

9. IO.

Haryana Himachal Pradesh

February-May July-November July-October July-October

II.

Jammu and Kashmir

Foothills

A. A. A. A.

culicijacies jkiarilis culicifacies ,%niatilis

March-April Plains

June-October 12.

Karnataka

A. f?uriarilis

Hills

October-June Plains

13. 14.

Kerala Manipur

IS.

Madhya Pradesh

July-December January-June Perennial

A. balabacenris

Hills

A. caruna

September-November Plains

June-October lb.

Maharashtra

Hills and forest

areas

A. culicif%es A. Jkiatilis

Perennial Plains

17.

Nagaland

February-May June-November Perennial

18.

Orissa

Hills

A. A. A. A.

Perennial

culicifacies stephensi minimus bolabacensis

A. jluviatilis A. minimus A. cmuno

Plains

February-March September-November 19.

Punjab

A. annularis A. nutdnicw

A. jeyporiensti A. oconifur

Hills

April-October

A. ,kGztilis

PlUinS

July-October

A. culicifucier

A. stephensi

Source: Manual of Malaria Eradication [26].

was complete lack of information on either the existing or increasing receptivity and vulnerability of different regions of the country. These conditions played an important role in malaria outbreaks and were the main centres of resurgence. The Madhok Committee [13] also noted that such factors as the disturbed conditions in various parts of the country like Nagaland, Mizo district of Assam, border areas of Tripura, Bastar district of Madhya Pradesh and NEFA; Indo-Pakistan conflict in Westem sector frontier areas from Jammu and Kashmir to

Rajasthan and Gujarat; and delays in financial sanctions and initiation of surveillance operations in the border areas of Uttar Pradesh, Bihar, West Bengal etc., had also affected the eradication programme. The programme also faced a variety of other problems such as the refusal to accept DDT spraying by a large section of community on religious grounds or the false belief that malaria had been eradicated, constant movement of labour due to developmental and construction projects where regular anti-malaria operations were not undertaken, the problem of

hlalaria resurgence in India: a critical Table

I?. Vectors

in units of oersistent

attack

ohase

Seasonal Perermal I. 2. 3.

4. 5.

6.

7. 3. 9.

culicifacies A. culici/acies and A. puciarilir A. culicr/acies. .4. srrphensi and ..I. philippinensis A. minimus A. minimus. A. balubocensis and A. philippinensis A. minimw, A. flusiardis and A. cu1ic1yacies A. annularis A. annularis and A. ,f?ucioriiis A. sundacus Total A.

Source: in-depth

evaluation

Total

8

3

II

21

28

49

8 0

2 14

IO

0

5

5

0

I

I

I

I

2

0

I

39

57

I4

96

1970 [14].

nomads and tribal areas including the outdoor sleeping habits, refusal to accept spray in silkworm rearing areas, habit of mud-plastering of houses immediately after the spray, and frequent breakdown of the vehicles. In addition to these problems, a large number of key supervisory posts remained vacant for long periods resulting in inadequate supervision and technical guidance at the periphery. States’ disinterestedness in the programme by way of delayed or piece-meal financial sanction to NMEP in certain states, and failure to ensure working of basic health services satisfactorily and diverting basic health workers for other health programmes compounded the problem [14]. RELATIONSHIP

TO

AGRICULTURE

Between 1965-1970, malaria had resurged in large parts of the country and the disease had been well established. Therefore, for any study on malaria resurgence, this period is most critical, as in the later years the return of malaria became more or less a matter of fait accompli. Table 13 gives the Indian agricultural statistics. During 1960-1965 there was no noticeable increase in gross cropped area and food production. The use of pesticides was also negligible. In later years, there was about a 5-10% increase in gross cropped area and food production. High yielding varieties (HYV) were introduced in 1966 and the total area under HYV was about 5-10%. During this Table

Year 1960 1961 1962 I963 I964 I965 1966 I967 I968 I969

Gross cropped area (‘000 ha)

Irrigated area (‘000 ha)

152772 156209 156760 156963 I59229 I55276 157355 lb3736 159529 162265 165791

2466 I 24884 25665 25888 26600 26344 26907 27193 29009 30197 31103

lHYV programme was launched in 1966-1967. Source: fertilizer statistics, fertilizer association

0 0 0 0 0 0

laab*

6036 9297 II413 I 5383

of India

8-13

period increasing quantity of pesticides were used in agriculture, but these pesticides belonged to several groups and the total quantity of insecticides used in agriculture was about equal to the use of DDT in public health. It is unlikely that in a period of 2-3 years, the indirect use of a variety of pesticides in agriculture would induce a high level of DDT resistance in vectors of malaria, so as to thwart control efforts. The irrigation and the use of fertilizers steadily increased during the decade, but as far as we know fertilizers have no role to play in the evolution of resistance in the field, although irrigation may have provided additional breeding grounds for the mosquitoes. Table 14 gives the cropped areas under cotton and paddy in the southern states, Orissa and Gujarat from 1960-1976. The area under cotton in the southern states and Gujarat has remained at the same level from 1960 to 1976 and so has been its yield [9]. Cotton growing seems to have no relationship to malaria. as cotton is not grown in Orissa, and malaria resurged at a much faster speed in that state. The area under HYV of paddy in the southern states increased considerably, but it is noteworthy that while malaria outbreaks were becoming common during 3965. 1966 and 1967 there was a declining trend of malaria in Andhra Pradesh, Tamil Nadu and Karnataka. In Orissa, the area under HYV of paddy was about equal to that in Kamataka but there was no concurrent increase of malaria cases in Kamataka as happened in Orissa. And lastly the case of Gujarat where the area under HYV of paddy was only 25-30% to that of Tamil Nadu, but malaria resurged with vengeance in Gujarat and not in Tamil Nadu. Therefore. there seems to be no relationship of malaria to either the growing of cotton or paddy or of the introduction of HYV of these crops. It may be noted that malaria resurged in central and north Indian states much more than in the southern states (Table I). An analysis of the malaria incidence revealed that the total cases in Andhra Pradesh, Kamataka. Tamil Nadu and Kerala for a period of 6 years (1965-l 970) were 59,681, i.e. 2676 cases less than recorded in one year (1966) in Madhya Pradesh. Also during 1966 there were 17,170 cases in Gujarat where intensive agriculture was practised and during the same year total cases in Madhya Pradesh were 62,356 (3.63 times more), a state where intensive agriculture was not practised. Therefore, at least in the Indian scenario, there is no scientific basis to blame intensive

13. All India anricultural Area under HYV (‘000 ha)

study

statistics

Fertilizer consumption (‘000 tonnes)

Total food production (‘000 tonnes)

Pesticide use in agriculture (‘ooo tonnes)

239.9 338.3 452.2 543.9 773.2 784.6 1100.6 1539.0 1760.7 1982.4 2256.0

82018 82706 80151 80642 89356 72347 7423 I 95052 94013 99501 108422

2.0 3.8 4.6 4.5 6.2 6.1 7.4 I I.2 14.0 I 1.8 10.1

(198&1981)

V. P. SHARMAand K. N.

84-t

MEHROTIU

Table II.Area under cottonand high yielding varieties of paddy Karnataka

hndhra Pradesh

Tamil Nadu

Gujarat

Year

cotton

Paddy

cotton

Paddy

cotton

Paddy

cotton

1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1971 1972 1973 1974 1975 1976

313 354 365 423 389 325 307 322 301 321 316 337 303 413 434 274 281

0 0 0 0 0 0 275 351 205 676 512 725 I200 1811 2413 2471 2024

1035 960 1026 1036 IO35 958 983 1088 1061 1048 995 1078

0 0 0 0 0 0 30 45 74 109 I62 160 202 280 295 575 400

396 403 401 419 424 407 407 360 382 345 311 313 297 303 247 261 238

0 0 0 0 0 0 I52 4-l? 639 II42 1819 2245 2245 2144 1860 1860 2170

1698 1632 1696 1687 I740 1726 1739 1650 1608 1647

aaa

998 1077 997 79s

I582

1847 1790 1863 1595 1777 1726

Orissa

Paddy 0 0 0 0 0 0 3 5-I 27 2s 49 60 56 8s 94 172 I78

cotton 0.7 7 8 2 I I I

I

0 0 0 0 0

I 2 3 5

Paddy 0 0 0 0 0 0 46 I21 146 I71 IS? 253 400 360 313 483 557

Source:fertilizer statistics, fertilizer association of India(1980-1981). Note: allfigures are in thousandhectares

agriculture or the introduction of high yielding varieties programme for the resurgence of malaria. CONCLUDING

REi%lARKS

The spectacular success in malaria control infused a false sense of confidence that malaria was on its way out. While malaria was raising its head, the malaria organization was being wound up. In 1963, the internationally noted centre of excellence in malariology, the Malaria Institute of India, was converted to the National Institute of Communicable Diseases, and even the publication of the one time famous, Indian Journal of Malariology, was terminated. Research on malaria was de-emphasized and malaria was no longer a preferred vocation. During the critical years of resurgence, there was no research support to the programme, as a result there was complete lack of information on the receptivity and vulnerability of different regions of the country under the changed ecological frame. There was also the widespread occurrence of parasites in urban and rural areas of the country, and vector populations returned to their normal densities after the withdrawal of spraying. As a result malaria resurgence occurred throughout the length and breadth of the country. Ironically the malaria control programme was converted to that of eradication mainly to save perpetual costs and eliminate the disease before the large-scale onset of insecticide resistance. But that was not to be true, instead today the programme is confronted with the formidable problems of insecticide resistance, drug resistance and problems related to management. In areas where there is any relaxation in control

efforts. extremelv hioh incidence and focal outbreaks have been recorded-[20,26-291. With this background, the phenomenon of resurgence is to be examined from the point of view of the reproduction rate of malaria as evolved by Macdonald [30]. Ramachandra Rao [31] has prepared a table from the well known graph of Macdonald to show the importance of reproduction rate. Table 15 shows that epidemics affecting 50% of the population can occur in 7 months time even if the reproduction rate is as low as 5 and in 4-5 months if the reproduction rate is 20. It is the mosquito factor which is liable to gross and rapid changes and has the profound influence on the reproduction rate. The presence of a small number of cases in consolidation and maintenance phases and the urban areas, coupled with the failure in vector control set a chain of events leading to the multiplication of malaria cases in India. The total cost of malaria control in India until 1973-1974 was Rs.2562 millions. Compared to this, the Government of India is spending Rs.2000 million annually, and there are demands for higher allocation. The escalating cost of insecticides, antimalarials and labour etc., may further push up the cost, and there are no easy solutions in sight. Therefore, there is an urgent need to intensify research on alternative methods of vector control, and until then we will have to continue to depend on the insecticidal spraying to interrupt transmission. With this background, it is obvious that for successful malaria control, whether today or tomorrow, people’s participation is absolutely essential, and in the future, much will depend on the ‘Community-will’. REFERENCES

Table 15.Time

taken in days (approx.)for 50% of human population to become infected at different reproduction rates, with an initial parasite rate of 0.1% Reproduction rate P. t&7x P. falciparum 5

IO 20 50 100

215 I55 I10 80

65

Source:The Anophelines of fndia [31].

Over 300 220 I60 120 IO0

1. Chadha Committee. Report of the special committee on the preparation for entry of the Sational Malaria Eradication Programme into the maintenance phase, 1963. 2. Report of the consultative committee of experts to determine alternative strategies under Sational Malaria Eradication Programme, 1974. 3. Pattanayak S. and Roy R. G. Malaria in India and the modified plan of operations for its control. 1. Communicable Dis. 12, I-14, 1980.

Malaria

resurgence

in India:

4. Chapin G. and Wasserstrom R. Agricultural production and malaria resurgence in Central America and India. Nafure, Lond. 293, 181-185, 1981. 5. Chapin G. and Wasserstrom R. Pesticide use and malaria resurgence in Central America and India. Sec. Sci. Med. 17, 273-290, 1983. 6. Bruce-Chwatt L. J. Malaria debated. Nature. Lond. 294, 302-303, 1981. 7. Curtis C. F. Malaria debated. Narure, Lond. 294, 303. 1981. 8. Singh P. P. The return of malaria to India. Nafure. Lond. 296, 496, 1982. 9. Sharma V. P. and Mehrotra K. N. Return of malaria. Nature, Lond. 298, 210, 1982. 10. Sharma V. P. and Mehrotra K. N. Malaria resurgence. Nanrre, Lond. 300, 212, 1982. 11. Sharma V. P. and Mehrotra K. N. Final words on malaria’s return. Nature, Lond. 302, 372, 1983. 12. Chapin G. and Wasserstrom R. Final words on malaria’s return. Nature, Lond. 302, 372, 1983. 13. Madhok Committee. Report of the special committee to review the working of the National Malaria Eradication Programme and to recommend measures for improvement, 1970. 14. Report of the evaluation in-depth of the National Malaria Eradication Programme of India, 1970. 15. Report of the Committee set up to study in-depth all relevant aspects of the National Malaria Eradication Programme, 1974. 16. Committee to recommend larvicides other than mosquito larvicidal oil, 1973. 17. Roy R. G.. Panchapakesan A., Sitaraman N. L., Ganesan A. V. and Ghosh R. B. The urban malaria problem in Tamil Nadu state. Indian J. med. Sci. 30, 313-316, 1976. 18. Pattanayak S., Roy R. G., Samnotra K. G. and Bendley M. S. Urban malaria scheme of the National Malaria Eradication Programme of India. Indian J. Malar. 18, 21-27, 1981. 19. Malaria in India through the years. Cyclostyled document compiled by D. D. Arora, 1980.

a critical

study

84.5

20. Sharma V. P., Uprety H. C.. Nutan Nanda.. Raina V. K., Parida S. K. and Gupta V. K. Impact of DDT spraying on malaria transmission in villages with resistant dnopheles culici/acies. Indian J. Malar. 19, 5-12, 1982. 21. Raghavan N. G. S., Wattal B. L., Bhatnagar V. N.. Choudhury D. S., Joshi G. C. and Krishnan K. S. Present status of susceptibility of arthropods of public health importance to insecticides in India. Bull. Indian Sot. Communicable Dis. 3, 209-245, 1966. 22. Kalra N. L. Susceptibility of common mosquito species of Andaman and Nicobar Islands to insecticides. J. Communicable Dir. 13, 45-52, 1981. 23. Singh N. and Chakrabarti S. C. Susceptibility of Anopheles philippinensis to DDT from some areas of India bordering Bangladesh. J. Communicable Dis. 11, 85-88, 1979. 24. Dutta-Choudhury J. and Malhotra P. R. Susceptibility of Anopheles philippinensis to DDT and dieldrin in Assam. Indian J. Malar. 19, 145-146, 1982. 25. Manual of Malaria Eradication Operation, National Malaria Eradication Programme, 1960. 26. Sharma V. P., Choudhury D. S., Ansari M. A., Malhotra M. S., Menon P. K. B., Razdan R. K. and Batra C. P. Studies on the true incidence of malaria in Kharkhoda (Distt. Sonepat. Haryana) and Kichha (Distt., Nainital, U.P.) Prima? Health Centres. Indian J. Malar. 20, 21-34, 1983. 27. Uprety H. C.. Gupta V. K. and Sharma V. P. Modified plan of operation and its impact on malaria. Indian J. Malar. 19, 137-138, 1982. 28. Choudhury D. S., Malhotra M. S., Shukla R. P.. Ghosh S. K. and Sharma V. P. Resurgence of malaria in Gadarpur PHC district Nainital, Uttar Pradesh. Indian J. Malar. 20, 49-58, 1983. 29. Sharma V. P. and Uprety H. C. Preliminary studies on irrigation malaria. Indian J. .Ualar. 19, 139-142, 1982. 30. Macdonald G. The Epidemiology and Control of Malaria. Oxford University Press, London, 1957. 31. Rao T. R. The Anophelines of India. Delhi Press, India, 1984.