OONFERENCE ON MALARIA

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REPORT OF

THE EIGHTH BORNEO OONFEmNCE

Keningau, North Borneo 16 - 18 June 1959

World Health Organization Western Pacific Regional Office

Manila, Philipp ine s July 1959

WPR/MAL/3 27 July 1959

ENGLISH ONLY

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CON'lENTS

PROGRESS OF COONTRY MALARIA PROGRAMMES

Republic of Indonesia

North Borneo

Sarawak

I'IEMS OF SPECIAL INTEREST

Inter-territorial eo-operation

Migrator,y groups

Investigation

Surveillance

Insecticides

SprlVing equipnent

Personnel training and health education

The problem of spr~ing operations

Drug administration

ANNEXES

MAPS

List of participants

Programme and agenda

Area of residual spr~ing operations in Sarawak, 1958

Area of residual sprCliYing operations in Sarawak, 1 Januazy-30 June 1958

Area under active surveillame in Sarawak, 1959

Area proposed to be under active surveillance in Sarawlic in 1960

Distribution List

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Fig. 1

Fig. 2

Fig. 3

Fig. 4

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COOFEEiENCE ON MALARIA

REPORT CF THE EIGHTH BORNEO MALARIA OJNFEEiENCE

WPR/MAL/3 pagel.

The Eighth Borneo Malaria Conference was held in the Malaria Laborat£r)",

Keningau, North Borneo. The meet:ing was attendedl tv representatives of the

Governments of the Republic of Indonesia, North Borneo and Sarawale; by

observers from the BrIlnei Shell Petroleum Company Ltd., the Inte~ational

Co-operaticn Administration in the Republic of Indonesia, WHO Project Staff

from Indonesia and. the British Borneo Territories, the WHO Regional Entomol.o­

g:1st and the Regional Sanitary Engineer for the Western Pacific Region.

The Conference was decl.ared open by Dr L. J. Clapham, Director of Medical

Services, North Borneo. He extended a warm welcome to all the participants,

and asked the partiCipants to discuss freelj' as this conferewe was 1nf'ormal

and pur~ technical •

Dr M. E. Santa Maria, WHO project leader in North Borneo, was elected

chairman, and Professor C. Y. Chow, Regional Entomologist, was elected rappol'­

teur.

In view of the fact that Dr Cl~ham had to return to Jesselton immediatel;r

after the adoption of the agenda, 2 it was felt appropriate to respond to his

welcaning address at that moment. Dr I. D. Carter on behalf of all the parti­

cipants, and Dr H. T. Soeparmo on behalf of his gOV'ernment, thanked Dr Clapham.

1 The list of participants is given in Annex: I.

2 The agenda is given in Annex II •

WPR/MAL/3 page 2

PROORESS OF COUNTRY MALARIA PROGRAMMES

Brief descriptions were given of the development and progress of malaria

programmes, and a resume is reproduced in this report.

1. REPUBLIC OF INDONESIA

The plan of operations covers a period of eleven years and envisages a

progressive expansion of tre areas under eradication until the entire popula-.' . .

tion of 15 million exposed to malaria risk is covered. In Ma,y 1959 1V a

Presidential decree a Malaria Eradication Board was established. This Board,

presided over qy the Minister of Health, is composed of representatives of the

different Ministries with the Director of the Lembaga Malaria as Secretary.

The vmo and ICA serve as advisers to this Board. A Malaria Eradication Service

under a director has also been inaugurated qy governmental decree. The Director

of the Malaria Eradication Service is responsible through the Director of the

Lembaga Malaria to the Malaria Eradic ation Board for too implementation of 1:he

programme.

In 1959, seven zones in Java and one :lOom in South Sumatra were being

covered. The trai~ of zone and sector chiefs for the eight zones has been

completed, and geographical reconnaissance is in progress. It is expected that

the spraying which has alreaqy started in two zones will be in progress in all

eight zones qy the end of 1959. Each zone has a population of about 1.4 million.

IDT at the dosage of 2 gm. technical per sq. m. is spra,ved twice a year. In the

sundaicus areas dieldrin at the dosage of 0.5 gm. technical per sq. m. is used

at an interval of eight months.

A case-finding programme by the use of voluntary workers will be cOlllllenced

chlring the attack phase and fever cases will be treated wi th s~le doses of a

4--aminoquinoline. For purposes of assessment malariometric base line data will

be collected qy mobile assessrent teams from selected index areas before sprqillr;.

Parasite surveys of trese areas will be repeated every year during the attack

phase.

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WPR/MAL/3 page 3

The programne also includes four stuc\y" teams for undertaking studies on

aspects of the work that have a direct bear~ on the eradication programme.

The training of adequate rmmbers of personnel in all categories is an

important part of the prograIQIle. All senior personnel such as malar:l.ologists,

entanologists, etc. 'Will be sent for training to international training centres

such as the Jamaica Malaria Eradication Training Centre and the Philippine

Institute of Malariology at Tala. AJ.I the junior technical persormel will be

trained in the cruntlY. For this purpose a training centre will be established

in Java. for zone and sector chiefs. The instruction will be in Indonesian

(Malay). It may be possible to extend the facilities of this train~ centre

to the neighbouring countrie s where the sare language is spoken. The lower

categor,y of personnel will be trained at provincial and zone levels.

Kalimantan

According to the plan of operations pre-eradication activities in this

area will start in 1960 and sprSiYing will be undertaken in West Kalinantan in

1961. During 19 5~ 59 malariometric surveys and studies on the bionomics of

vectors were undertaken in a few areas in Kalim3.ntan. It has been observed

that the endemicity is high in the relativel,y sparsel,y populated interior

villages. General4r speaking, along the coast the endemiciv varied from spleen

rate 15% to m. The entomological studies conducted in Kalinantan resulted in

the following findings.

Vectors I

(1) ~. leucosphyrus leucoBPhyrus - 43 specimens dissected showed 2 gland

positives and 4 gut positives.

(2) !.. venhuisi (according to Reid, this species should be. called as

~. nigerrinms) - I 'Z70 specimens dissected showed one gut positive.

The vectorial role of this mosquito needs confirmation.

(3) A. umbrosus and A. letifer have been reported as vectors by earlier

workers.

WPR/MAL/3 page 4

, . The peak of entry into houses and feeding of leucosphyrus has been found

to be between 10 p.m. to 1 a.m. Most of the specimens escape from the houses

during the last quarter of the night.

2. NORTH BORNEO

Evidence of the interruption of transmission was obtained in the area

(Keningau South) after three rounds of dieldrin residual sprayiI:f; at the

dosage of 0.6 gm. technical per sq. m. at an interval of six months concurrent

with four mass drug administrations.

On the Island of Labuan, where on1¥' dieldrin was sprayed at the dosage of

0.6 gm. technical per sq. m., annual1¥' in the first year and semi-annual1¥'

later on, no positive case was found in infants after the third round of

SPrlViI:f;. The infant parasite rate which was 0.5 percent (186 examined in

1951) had dropped to zero since the beginning of 1958. It was proposed to

carr.r rut a case finding progranme in addition to infant parasite survey.

Entomological findings

Although considerable time was spent qy the entomological staff in

helping with the supervision of spraying and drug administration, the following

findings were obtained during the period from the Sixth Conference up to date.

(1) Dissection - !::. barbirostris was found positive with sporozoites (ore

out of 20 dissected) for the first time.

(2) Insecticide-susceptibility tests:

S :ipecies Area DDT % LC 50 Die 1 drin

Bal abacensis unspr~ed 0.'51 -5 X DDT 0.55 -

Barbirostris unsprayed 1.05 0.01

1 X DI1f 1.45 0.09

4 X DLN - 0.04

5 X DDT 0.72 -Sundaicus unspr~ed 0.6 - 0.8 0.04 - 0.0,

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WPR/MAL/3 page 5

The above shows that the vectors are still susceptible to DDT and

dieldrin •

(3) Denai ty in night collections - In da;vt:ime there were usua.lJy no vector

mosquitos (balabacensis and barbirostris) found :In human dwellings even

in unspr~ed areas. Night collections had been, therefore, carried out

in the spra;ved areas. Neither balabacensis nor barbirostris had been

found inside the human dwellings sprayed with 1 roum of DDl' or dieldrin,

or 4 rounds of ·dielrlrin or 5 rounds of DDr. Night collections from out­

doors where buffalo were used as bait revealed that a considerable number

of barbirostriB (1.5 - 5.8 per man-hour) cruld be caught in all the

sprayed areas under observation, but balabacensis (0.7 per man-hour) was

found o~ in the area 8pr'Ved with five rounds or DDT.

(4) Bioass8iY' - This bald been undertaken in the areas sprllYed for the fn-at

"" tilne. Up to date, three Ilonthe atter ap~1rlg, results were still ve7ll' ~

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Bati~!actor.; in both DDT and dieldrin areas.

lhildings

Excellent office and laboratory building shad recent4r been completed and

put into use. Additional staff recruitment will be completed on 1 July 1959.

3. SARAWAK

Since October 1958 there had been total coverage of all areas in which

malaria transnisaion was lmown to have occurred.

Malariometl":'.cal information had been obtaired in conjunction with the

sprSiYing operations by the taking of bloods from infants and children to the

age of 5 years and all fever cases. Very few positive infants were fOW'li

throughout the cruntry although there were a considerable number of positives

amongst the fever cases.

In general there was a reduction :in the :incidence as canpared with the

information gathered during the preceding spra;viI€ operations •

WPR/MAL/3 page 6

Surveillance operations continued in the trial area in the First Division

and wore introduced in January in the Baram District.

Positive infants detected in this work, and the few that were detected as

a result of bloods collected durjng sprlV~ operations, were investigated.

Mosquito captures were carried out in the houses in which the positive

infants lived. These captures in no case yielded significant rmmbers of

proven vectors. Insufficient rmmbers were caught to use for bio-ass~. All

mosquitos caught were dissected but none was found to be positive.

Two of the junior national staff were atten~ the crurse in malaria

eradication at the Tala Institute of Malariology on fellowships granted by the

Government of the Philippines under the Colombo Plan. Other tr~ was

conducted loc~.

Two cycles per anrmm of total coverage will be the goal, with the expan­

sion of surveillance to those areas in which, from malariometric al infomation,

transmission was believed to have been interrupted.

ITEMS OF SPECIAL lNTEREST

Inter-territorial Co-operation

All the partic:ipants agreed that conferences of this nature, where

malaria workers of neighbouring countrie s could meet, discuss their conmon

problems and pool their experiences, formed one of the best means or inter­

country co-operation. In addition it was suggested that the co-operation

should be extended to include the following:

(l) Periodic exchange of infomation regarding the progress of anti­

malaria operations: This could be done 1:u exchanging semi-annual repcrts

thrrugh the agency or WHO. Information on a:ay items of special interest, such

as the detection of vector resistan:e or the occurrence of abnormal increases

in malaria incidence in the border areas, should be c CJllIIIWlic ated to the neigh­

bouring country by the most expeditious means.

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WPR/MAL/3 page 7

(2) Trair:i...'1g of personnel: A training centre imparting instruction in

the Indonesian (Malqy) language for training chiefs of zones and sectors and

subordir.atE: staff was expe cted to open ill Java in September 1959. The possi­

bility of making the tra.ini~ facilities available to candidates from countries

in Borneo was mentioned by the participant from Indonesia.

(3) Facilities for the passage of anti-malaria persomel across borders

to reach inaccessible enclaves: It was felt that this matter was beyond the

scope of the Conference and it was recommended that it should be discussed at·

the next administrative conference to be held in Indonesia with a view to

taking up the matter with the appropriate authorities.

(4) Co-ordination in tiloo and space of the development of eradicaticm

progralllIOOs: The importance of siImlltaneous development of anti-malaria

operations on both sides of the inter-country border was stressed by all

participants. In Kalimantan preliminary azTaQ5lAEmts for eraclicaticm are

planned to commence i."l 1960 for spra;ying in 1961. In Sarawak and North Borneo

the ma.laria control programmes had made considerable progress and it was

hoped that the"J wouJd be converted into eradication programmes in due course.

Migratorv groups

In Indonesia the problem of moving population falls under two groups:

(a) Land reclamm;ion and resettlement (Transmigration group) and (b) popul.a­

tion engaged in shifting cultivation and nomads. As the eradicatl.on prograD1le

was planned to develop accordling to a fixed schedule erlend~ year by year

to contiguous areas, the responsibility far t~ adequate and pranpt

emergency measures for dealing with malaria in areas outside tm sphal'E! of

activity of the eradication service fell to the local public service. An

adequate S'J_pply of ant:L":lC.larial drugs would be made available to the pr0-

vincial inspec-~orG of health •

WPR/MAL/3 page 8

In North Borneo land setUenent did not form a serious problem.

Sarawak migratory groups still present a problem of sane magnitude.

In

Further

work was needed to ascertain the prevalence of malaria in tl'Eso groups. Wben

the control programme was converted into eradication, the question of

ascertaining their transit routes and establishing check posts at strategic

points for blanket treatment of these group would have to be considered.

Investigation

The eradication organization in Indoresia includes four stuqy te8lll8 for

undertaking investigation on items that have a direct bearing on the eradica­

tion programne. The main activities will be directed to finding rut (a) the

optimum dosage of residual insecticides, (b) the frequency of sprSiring and

(c) the surfaces to be sprSired (whether animal shelters, caves and roofs

should be included in sprSiring). This includes stud:ies on the bionomics of

the vectors.

An important activity of these stuqy teams will be to assess tre efficacy

of different patterns of surveillance using both active and passive surveillance

technique s.

In North Borneo earlier work had shown that insecticide sprSiriIl! alone

did not completely stop transmission. However, dieldrin sprSiring combined

with drug administration had recentl;v resulted in a complete interruption of

transmission. By the end of the year it would be possible to assess the

results of DIY!' spraying combined with drug administration.

In Labuan, where d.leldrin sprSiring had been in progress since 1956 J there

was evidence that incidence of malaria had dropped to a very low level. A

case finding progranme would be started in that island as soon as the recessary

personnel became available.

In Sarawak special investigations had been carried out in sprSired areas

in which positive infants and a high incidence of malaria in children had

been found.

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WPR/MAL/3 page 9

In addition to bio-ass1V and other routine tests for determining tlle

effectiveness of insecticidal sprBiVing it was suggested that observation on

vector longevity, by using the simple method (tracheoles pattern on ovaries),

should be employed. By this method the nulliparous ani parous mosquitos

could be separated easily.

For insecticide-susceptibility tests of mosquitos, LC 100 should alB<> be

determined in addi. tion to tba:ir LC ~O.

Surveillance

The aim of rurveillance was to detect and effectively deal with all

cases of infection before they were able to produce secondary cases.

The pattern of surveillance organization required for each CCWltry

depended a great deal on the state of development of tba health service in

the country and the degree of public health awareness of the population.

Two of the D¥lst important questions to be decided in planning surveillance

were (a) the role of active and passive surveillance rEcessSlY' for the ear~

detection and treatllEnt of all parasite carriers and (b) the interval that

could safe~ be allowed between house visits (in active surveillance) withcut

running the risk of the production of secondSlY' cases.

In Indonesia an area in Central Java which had been under insecticide

sprqing for some years had been selected for .a special study. The efficacy

of the different surveillance patterns using voluntary collaborators and paid

workers would be judged by ccmpa.ring the number of parasite positive cases

detected by them against the number of parasite carriers detected £rom

repeated total mass blood surveys of selected villages in the area. The results

of similar surveillance studies that were nCM in progress in Ceylon and India

would be of great interest to Indonesia and the ofuer countries in BarrEo.

The interval between house visits would depend on the basic reproduction

rate of the parasite. This would depend on the density of the vector in

relation to man, the anthropophilic index, the sporozoite rate, the longevity

of the vector and the period of extrinsic cycle of the parasite. The

surveillance study programre in Indonesia had plans for undert~ observation

on. all those aspects.

WPR/MAL/3 page 10

In Sarawak although the programme was still a malaria control ore it had

been possible to start an active case finding programme in 3 districts - Serian,

Kuching and Baram. A total population of 81 000 had been visited at mont~

intervals over a period of six months. Blood had been taken from all cases of

fever and those with history of fever. A single dose of a 4 - aminoquinolire

had been administered to all fever cases. Those found positive were treated

also with single dose treatment during subsequent house visits at month~

intervals. In the Secian district with a population of 33 000, during the

peri~d November 1958-April 1959, 214 paraSite positive cases were detected

whereas in the Kuching district (29 000 population) onJ;y- 49 parasite positives

were found during the same period. The concurrent treatment of malaria

carriers along with the spr8i"ing would hasten too end point of malaria and

thereb,y facilitate eradication.

Insecticides

There was little to be added to what had already been mentioned in pre­

vious conferences.

Spr~ equipment

The chief concerns in Spr8i"ing equipment were the qualiW, the performance

and the frequency of charges on turnover.

Most of the rCA and UNICEF supplied sprqyers were obtained from U .. S.

manufacturers. The system of purchasing them had been improved by a system

of permitting on~ those with proven good equipment, as tested by the U.S.

Public Health Services laboratory, to qualif,y in the bidding.

The qualities contributing to good performance had been consolidated into

a new d3sign which met the WHO specifications. The improved features were the

result of the experience in the Mexican programme and the new Hudson spr:ver

was a wpic al one.

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WPR/MAL/3 page 11

Size preference, choice between the 4 and 3 - U.S. gallon sprayers, had

been based on the size of the spra:ymen. In North Borneo where the sprlJ¥lOOn

spent more time in travel on foot than actual spraying in the house, this

sounded reasonable. In Taiwan, however, where the spra:ymen were not any

larger in stature, preference :L"'l size was not a cC::Ice:-n. In an eigh .. hour

work, distance from house to house did not alter the load if the spra.vmen

worked all the time. The new spra;ver, however, was a 4 - gallon equipment.

The value of constant pressure gadgets had been vE1r'Y disappointi~ in

many projects. Steaqy performance for a reasonable t:lme had never been

demonstr ated fran too type of sprayer provide d.

Erosion of nozzle tips could result in unnecessary increases in con-

. SllIlption of insecticide to about 25%, before routine changes of nozzle tips

were made. A discarded nozzle tip also meant ore U.S. dollar lost. A recent

development, an adapter, developed tu the Equipm:mt Development Laboratory at

Savannah, Georgia, might be available soon as a salut ion to the erosion and

wide variation of discharge from too spr8iY"er. The adapter was essentially a

gasket which could be inserted behind the nozzle tip; it lasted a week longer,

and it was vezy cheap too.

Personnel training and health education

This had been dealt with in general in the preceding items. In North

Borneo intensive training of laboratory technicians was urgently required.

It was suggested sane of thom could be sent to the Philippine Institnte of

Malariology at Tala, or elsewhere, for train~.

The importan::e of health education at all levels in mal aria eradication

c~aigns was streosed- lYJ an· t.he participcrlts. It was agreed that health

education should form an integral part of all r,,stional antimalaria prograzrmes.

The services of the specialized health education section of the goverrment

could be profitably employed for advising the antimalat'ia services on the

methods and techniques of health propaganda.

WPR/MAL/3 page 12

Problem of spraying operation

Timing the spraying with the idea of spraying just before the trans­

mission peak in the shortest period possible was discussed. The consensus of

opinion was that this did not aPplJr in Borneo since (a) transmission was

continuous the whole year and (b) the workers had to be hired for a long period.

It was noted that the reason for increased consumption of insecticide in

North Borneo was said to be due to the inclusion of all farm huts ani the

spra;y~ of the eaves and undersides of houses.

Drug administration

In general single dose treatment using a L.-aminoquinoline was the method

in the malaria eradicati. on programre in Indone sia and plus pyrimethamine in

addition in British Borneo. In Sarawak the drug used was a combination of

L.-aminoquinoline plus pyrimethamine in tablets each containing 200 mgm. chloro­

quine and 16.5 mgm. of pyrimethanine. Three such tablets were given as a

single adult dose.

Date and Place of Next Technical r-!eetiIE

The date and place of the Tenth Borneo Malaria Conference (technical) would

be discussed at the Ninth Conference to be held in Indonesia next December.

Adj ournmen t

On behalf of the GoverlllOOnt of the Republic of Indonesia, the WHO Regional

Directors for South-East Asia and the Western Pacific, the ICA in IndoneSia,

the Brunei Shell Petroleum Co., and all the partiCipants, thanks were given

to the Government of North Borneo for act~ as the host. Dr Nicholson, on

behalf of the Government of North Borneo, thanked all the participants for

attending the Conference.

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LIST <F PARTICIPANTS

GovernIlEnt of North Borneo

Dr L. J. Claphan, Director of Medical Services, Jesselton

WPR,/MAL/3 page 13

ANNEX I

Dr J. A. B. Nicholson, Deplty Director of Medical Services, Jesse11xm

Dr J. Graves, Medical Officer, Keningau

Govermu:nt of the Republic of Indonesia

Dr H. T. Soepanno, Director, Lembaga Malaria, Djakarta

Govermnent of Sarawak

Mr Joseph Yong, Laboratory Superintendent, KuclUng

Observers

Mr E. A. Smith, Acting Chief Malariolcgist, ICA (Republic of Indonesia)

Mr Loke Yee Wei, Chief Health Inspector, Brunei Shell Petroleum Co., Ltd.

World Health Organization

SEARDs Dr G. Sambasivan, Senior Malariologist, Republic of Indonesia

Mr S. N. Saxena, Assistant Malariologist, West Kalimantan, Republic of

Indonesia

VPRO:

Professor C. Y. Chow, Regional Entomologist

Mr p. S. Echavez, Regional Sanitary Engineer

Dr M. E. Santa Maria, Malariologist and Project Leader, North Borneo

Dr I. D. Carter, Malariologist and Project Leader, Sarawak

Dr F. Y. Cheng, EntomolOgist, North Barneo

Dr G. Kudicke, Malariologist, Sarawak

Mr J. W. C. Armstrong, Sanitarian, Narth Barneo

Mr Peter Grahan, EntOlIIOlogist, Sarawak

Mr George Leport, Laboratory Tecbni.cian, North Borneo

WPR/MAL/3 page 14

ANNEX II EIGHTH BORNEO MALARIA OONFEHENCE

PROGRAMME

16 June 1959 Arrival of participants

17 June

18 June

19 June

Visits to the Malaria Compound (office, laboratories and

quarters).

Demonstration of mosquito age determination and bio-ass~.

Conference (starti~ 8: 30 a.m.)

Conference

Field visits

Departure of pArticipants

AGENDA

1. Opening, election of chairman and rapporteur

2. Adoption of provisional agenda

3. Progress of country malaria programmes

3.1 Malariometrical and entomological findings

3.2 Spra;yirg operations

3.3 Mass drug administration and surveillan: e

3.4 Trai~ 3.5 Administrative matters

3.6 Plans for the future

4. Items of special interest

4.1 Inter-territorial co-operation

4.2 Migrat ory grmps

4.3 Investigation

4.4 Surveillance

5. Technical items

5.1 Insecticides

5.2 Spra~ equipnent

5.3 Personnel training and health education

5.4 Problems of spr~ operation and drug administraticn

6. Date and place of next technical meeting

7. other busine s 5

8. Adjournment

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Report of the Eighth Borneo Malaria Conference

DISTRIBUTION LIST

Dr L. J. Claphan, Director of Medical Services, Jesselton (6)

Dr J. A. B. Nicholson, Deputy Director of Medical Services, Jesselton

Dr J. Graves, Medical Officer, Keningau

Dr H. T. Soeparmo, Director, Le;::o.baga Malaria" Djakarta (6)

Dr W. Gl¥n Evans, Director of Medical Services, Kuching (6)

Mr Joseph Yong, Laboratory Superintendent, Kuching

Mr E. A. Smith, Acting Chief Malariologist, ICA, Republic of Inoonesia

Mr Loke Yee Wei, Chief Health Inspector, Brunei Shell Petroleum Co., Ltd.

Regional Representative, United Nations Teclmical Assistance Board, Bangkok

UNICEF Resident Representative, Bangkok

Dr W. W. Yung, Area Representative, Singapore

Chief Medical Officer, Kuala Belait

Divisional Medical Officer, 2nd Division, Sirnanggang

Divisional Medical Officer, 3rd Division, Sibu

Divisional Medical Officer, Hospital Miri

Dr D. H. Colless, University of Mala;ya, Singapore

Dr J. A. Reid, Institute for Medical Research, Kuala Lwnpur

Regional Director, WHO Regional Office for South-East ASia, New Delhi

Dr D. K. Viswanathan, Senior Regional Malaria Adviser, SEAm

Dr G. Sambasivan, Senior Malariologist, Republic of Indones:ia

Mr S. N. Saxena, Assistant Malariologist, Republic of Indonesia

WHO Headquarters, Division of Malaria Eradication (3)

WID Heaiquarters, Division of Public Information (2)

Regional Director, WHO Regional Office for Western Pacific, Manila

Profe sear C. Y. ChOW', Regional Entomologist, WPID

Mr P. S. Echavez, Regional Sanitazy Engineer, WPRO

Dr M. E. Santa Maria, Malariologist and Project Leader, North Borneo

Dr I. D. Carter, Malariol~ist and Project Leader, Sarawak

Dr F. Y. Cheng, Entomologist, North Borneo

Dr G. Kudicke, Malariologist, Sarawak

Mr J. W. C. Armstrong, Sanitarian, North Borneo

Mr Peter Graham, Entomologist, Sarawak

Mr George Leport, Laboratory Technician, North Borneo

WPRO (30)