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THE MEDICAL AUXILIARY IN RURAL MALAYSIA
983 a quarter million acres of rice land, now sufficient water to grow each year two crops of rice. The use of high-yielding grains, fertilisers, and machines and the increased availability of facilities for processing and marketing are resulting in rapid sociocultural changes and a general raising of the standards of living of people in the rural areas. Another vast project in Pahang State involving 470 square miles for the cultivation of palm-oil and rubber will improve prospects for 10,000 settlement families.
Perlis, covering
Medical Alliance
ensures
THE MEDICAL AUXILIARY IN RURAL MALAYSIA
PAUL C. Y. CHEN
Department of Social and Preventive Medicine, University of Malaya, Kuala Lumpur
SELECTED TRAINING PROGRAMMES AVAILABLE IN
1972
WITHIN
MALAYSIA
THE PROBLEMS
MALAYSIA (which is composed of West Malaysia and the States of Sarawak and Sabah in Borneo) has a culturally diverse population of 10-5 million including Malays (44-4%), Chinese (35-3%), Indians (9-4%), Ibans (2-6%), and several indigenous tribes, such as the Kadazans, Muruts and Bajaus, and others. The problems that face Malaysia are not very different from those seen in other developing countries, the principal
diseases being malaria, helminthiasis, tuberculosis, enteric diseases, and leprosy. Other medical problems include nutritional deficiencies, trauma, and foci of filariasis, and there is always the threat of epidemic disease such as cholera. However, the basic problem is really one of rural poverty and ill-health. 73-3% of the population live in rural areas (urban being defined as towns with a population of 10,000 and over), where high rates of illiteracy, poor marketing facilities, a lack of capital, restrictive food habits and taboos, as well as the ravages of disease have kept the rural people trapped in a cycle of poverty leading to illhealth and ill-health leading to more poverty. BREAKING THE CYCLE OF POVERTY AND ILL-HEALTH
Since Independence, gained in 1957, the prime task has been to break this cycle. During the past decade there has been a rapid implementation of proposals for raising the standard of living of rural communities. Thus, the implementation of the Muda Irrigation Scheme in Kedah and
*
Professional with
a
t Paramedical with
a
minimum of A level secondary education. minimum of 0 level secondary education.
t Currently optional. § Increased in 1972
to
9 years.
The past decade has also witnessed the firm establishof a rural health service. The basic plan calls for one health unit for every 50,000 rural population, the unit being made up of one main health centre, four health sub centres, and 20 midwife stations (fig. 1). By the end of 1970, a total of 44 main health centres, 180 health subcentres, and 943 midwife stations had become operational. This rapid growth of the rural health services has created a great demand for health staff of all categoriesprofessional ment
(e.g., doctors); paramedical (e.g., nurses, hospital assistants, public health inspectors, and dispensers); and auxiliary (e.g., assistant nurses, midwives, and publichealth overseers). DISTRIBUTION, TRAINING,
AND
COST OF STAFF
Although the present ratio of doctors to population is 1 to 5000 in West Malaysia, the distribution is uneven. In urban areas the ratio is 1 to 1500, while that in the rural areas is 1 to 25,000, the distribution of paramedicals being similarly uneven. are not only scarce but also and require long and rigorous expensive, training. In 1969, only 1-4% of persons aged 19-21 years were enrolled in universities in West Malaysia. Although not as acute, there is a current shortage of paramedicals, particularly nurses. Paramedicals are recruited from school-leavers who have completed 0 level secondary
Professionals
Fig.
1-A rural health
unit, designed
to serve
50,000 people, and
a
hospital.
984
(fig. 3), with 1 professional, 13 paramedicals, and 45 auxiliaries, supported by 30 semiskilled/unskilled staff, for each rural health unit designed to serve 50,000 rural people.4 The most peripheral members of the rural health unit would be the 20 (singleauxiliary) midwives located at the 20 midwife stations of each unit, while the other auxiliaries consisting of the 15 assistant nurses, the 5 public-health overseers, and the remaining 5 midwives would be located in the main centre and four subcentres, together with the paramedicals, the doctor being based in the main health centre. This tiered pyramidal system, with its heavy reliance on the auxiliary and based on the principle of delegation to the lesser trained according to his abilities, has permitted the rapid establishment of the rural health services to cover over a third of the rural population in the short space of 15 years. At independence in 1957, the infant mortality-rate was 75-5 per 1000 live births, the toddler mortality-rate stood at 10-7 per 1000 toddlers, and the maternal mortalityrate was 3-2 per 1000 live births. By 1970 these rates had fallen to 40-8, 4-2, and 1-48, respectively.
purpose
Fig. 2-Average cost per day of staff rendering direct patient and health
care.
education (see accompanying table), and undergo training varying from 32 months to 63 months. In 1969, only 20-8% of the age-group 15-16 years were enrolled for 0 level secondary education. On the other hand, auxiliaries are recruited from those with 7-9 years of basic education, and, in 1969, 55-8% of the age-group 12-14 years were enrolled for such an education.1 Professionals are expensive to employ as well as to
The Indigenous Midwife Delegation can also extend from the trained midwife to the indigenous midwife (bidan kampong), with whom a working partnership can be cultivated. In 1970 of births indigenous midwives attended 32% registered in West Malaysia. For a number of years now, a simple course of training has been conducted on an experimental scale. The aim is to teach indigenous
In
Malaysia, paramedicals cost 40-82% less, cost 75-88% less than the doctor per working day (fig. 2). Not only do professionals demand high salaries, but the requisite professional and social environment has also to be supplied.2This can be provided in the major towns but not in the rural areas. produce.
while auxiliaries
midwives simple hygiene,
to recognise danger signals indicating a need for medical referral, and to participate in the family-planning programme. With the coming into force, in 1971, of the Midwives Act 1966, further regulating the practice of midwifery, indigenous midwives who had attended women during childbirth
THE AUXILIARY IN THE RURAL AREAS
for 2 years before enforcement of the Act have been permitted to register as legitimate midwives and have been placed under the supervision of the health authorities. It is envisaged that training courses will now be extended to cover all these indigenous midwives.
It is uneconomic to employ highly trained personnel in work which auxiliaries are capable of performing. Further, there is a need for trained persons who can carry out simple technical procedures that do not necessarily require the attention of qualified doctors.s An absolute dependence upon fully trained professional personnel will severely handicap implementation of health programmes in developing countries. Thus from the outset it was decided that a tiered system would be used to staff the rural health unit in Malaysia
Fig. 3-Staff pattern
in
a
rural health unit in the form of
THE FUTURE
In response
a
skill
pyramid.
urgent needs, a new auxiliary, the junior laboratory assistant, has lately emerged to take his place in the rural health unit. Demands created by the rapid establishment of rural
to
health services are sometimes best met by the training of large numbers of single-purpose workers such as the (auxiliary) midwife of Malaysia. However, single-purpose training is recognised as a temporary measure even though such auxiliaries may serve for several years. As sociocultural change occurs, and as expectations alter, such single-purpose workers should be retrained to meet new challenges. In Malaysia, plans are now being formulated to retrain the single-purpose
985
midwife in child health and nursing, and to give all assistant nurses midwifery training (currently optional) in order to equip these two auxiliaries for their new roles as multipurpose community nurse-midwives. Whatever changes may evolve with time, the experience of developed countries has shown that the need for auxiliaries will not diminish with the growth On the contrary, the of professional personnel. demand will continue and even increase, especially in developing countries. REFERENCES
1. Chee, H. Y. in Proceedings of the Second National Seminar on General Consequences of Population Growth, National Family Planning Board, Malaysia. Kuala Lumpur, 1970. 2. Fendall, N. R. E. Israel J. med. Sci. 1968, 4, 614. 3. Wld Hlth Org. tech. Rep. Ser. 1961, no. 212. 4. Jayesuria, L. W. A Review of the Rural Health Services in West Malaysia. Ministry of Health, Kuala Lumpur, 1967. 5. Malaysia. Midwives Act 1966.
Occasional
Survey
HEPATITIS-B ANTIGEN AND SAFETY IN PATHOLOGY LABORATORIES D. WATSON Area Laboratory,
I. L. CHRYSTIE J. BERTRAND
D. J. LANGLEY Edward VII Hospital, King Windsor
M. N. ISLAM J. E. BANATVALA
Department of Virology, Hospital, London SE1
St. Thomas’
possible, significantly assisting the clinical diagnosis. In one area laboratory, immune radiometry of sera from 400 patients and staff over a six-month period revealed only 2 sera with detectable H.B.A.1 At the same time several sera being distributed for qualitycontrol purposes were found to contain H.B.A. Because of this we have surveyed blood-serum products that are frequently used in pathology laboratories. METHODS
Products Tested These were 48 different lyophilised sera manufactured for control of precision and repeatability; also 38 similar commercial sera available for diagnostic purposes or standardisation of clinical analyses, which included 9 sera used for detection of blood-groups or antigens and 7 pure powders used for standardisation of protein analyses (all derived from pooled human plasma). In addition, there were 9 bovine-derived sera: ’ Precinorn E107 ’ and Precipath E104’ (Boehringer);’Lab-Trol 40F ’, ’Path-Trol 64AA ’, ’Enza-Trol 23TD ’, ’Choles-Trol ’ CTD309, and ’C.P.K.’ control 26 (Dade);’Wellcomtrol’assayed K4881, ’Wellcomtrol’ unassayed 2581 (Wellcome Reagents); and 4 horse lyophilised sera:Seronorm 113 ’ (Nyegaard/ B.D.H.); Control HA90BD and’Equitrol HA94 ’ (Tissue Culture Services, Slough); and ’H.C.S.’ (h-PL) (human placental lactogen) standard (Pharmacia). The maker’s recommended volume of reconstituting fluid-usually distilled water-was added to the vial containing lyophilised serum. In the case of the protein powders, approximately 4% w/v aqueous solutions were prepared for testing.
Immune radiometry (I.R.).- The method of Ling and Overby 2 was used. The two reagents required, Australia-antibodycoated tubes, 125I-Iabelled antibody together with 2M tris " (hydroxymethyl aminomethane) buffer concentrate, and a control solution containing H.B.A., are supplied by Abbott Laboratories as a kit (’Ausria-125 ’). The mean negative control count multiplied by 2-3 was regarded as a cut-off value. An expression of antigen strength is the ratio of the test count to the negative control count, and further quantitation is achieved by plotting this test-count/control-count ratio against concentrations of purified H.B.A. (Abbott). An experiment was undertaken to test the effect of serial dilution of an H.B.A.-containing commercial serum on the H.B.A. concentration measurable by this method. "
An
Summary
Australia-antigen screening
survey
carried out on 99 commercial blood products used in clinical-chemistry and hæmatology laboratories. 72% (35 of 48) of the lyophilised human sera used for quality control and distributed was
by eight American and one European companies contained the hepatitis-virus-B antigen (H.B.A.), one notable exception being eight sera from Technicon Instruments Corporation which were all H.B.A. negative. 36% (13 of 35) of other human-serumderived products used for diagnostic and standardisation purposes were also H.B.A. positive. A comparison of procedures for the detection and estimation of H.B.A. indicated that the methods recommended by an N.H.S. advisory group are too insensitive, yielding negative findings with potentially infective material. Manufacturers and hospital laboratories must be made aware that batches of such products should be regarded as high-risk specimens until more satisfactory screening procedures can be generally adopted. INTRODUCTION
BOTH
hepatitis (homologous serum jaundice, post-transfusion hepatitis, type-B viral hepatitis) and serum
infectious (type A) hepatitis are serious public-health hazards among those who handle blood or blood products. Biochemical tests to aid their differential diagnosis from non-parenchymatous liver disease (intra and extra hepatic obstruction) have long been used. However, routine detection of the hepatitisvirus-B antigen (H.B.A.) (and antibody) has become
Immune electron microscopy (I.E.M.).-Sera were incubated with anti-H.B.A. rabbit antibody (Hoechst Pharmaceuticals) according to the method described by Almeida and Waterson.3
Complement fixation (c.F.).-This was carried out as described by Taylor,4using three units of complement and four units of horse anti-hepatitis-B serum (Wellcome) at its optimum dilution and overnight fixation at 4°C. Immunoelectro-osmophoresis.-This test (i.E.O.P.; electroprecipitin ; counter-electrophoresis) was conducted using rabbit antiserum (Spectra Biologicals).5,G Tests were read without staining after seventy minutes’ electrophoresis. .HcsMM.g/MtMMfK’M.—Passive hacmagglutination (P.H.A.) was used for the detection of H.B.A. antibody and hsemagglutination inhibition (H.I.) for the detection of the H.B.A. Tests carried out according to a modification of the method Vyas and Shulmanin which 2-5 mM chromic chloride was used to couple the antibody to the erythrocytes; six H.B.A. units of rabbit antibody were used for H.I. tests, and to enable satisfactory settling of erythrocytes, normal human serum (blood-group AB at a dilution of 1/64) was used in were
of
the diluent.
Perlis, covering
Medical Alliance
ensures
THE MEDICAL AUXILIARY IN RURAL MALAYSIA
PAUL C. Y. CHEN
Department of Social and Preventive Medicine, University of Malaya, Kuala Lumpur
SELECTED TRAINING PROGRAMMES AVAILABLE IN
1972
WITHIN
MALAYSIA
THE PROBLEMS
MALAYSIA (which is composed of West Malaysia and the States of Sarawak and Sabah in Borneo) has a culturally diverse population of 10-5 million including Malays (44-4%), Chinese (35-3%), Indians (9-4%), Ibans (2-6%), and several indigenous tribes, such as the Kadazans, Muruts and Bajaus, and others. The problems that face Malaysia are not very different from those seen in other developing countries, the principal
diseases being malaria, helminthiasis, tuberculosis, enteric diseases, and leprosy. Other medical problems include nutritional deficiencies, trauma, and foci of filariasis, and there is always the threat of epidemic disease such as cholera. However, the basic problem is really one of rural poverty and ill-health. 73-3% of the population live in rural areas (urban being defined as towns with a population of 10,000 and over), where high rates of illiteracy, poor marketing facilities, a lack of capital, restrictive food habits and taboos, as well as the ravages of disease have kept the rural people trapped in a cycle of poverty leading to illhealth and ill-health leading to more poverty. BREAKING THE CYCLE OF POVERTY AND ILL-HEALTH
Since Independence, gained in 1957, the prime task has been to break this cycle. During the past decade there has been a rapid implementation of proposals for raising the standard of living of rural communities. Thus, the implementation of the Muda Irrigation Scheme in Kedah and
*
Professional with
a
t Paramedical with
a
minimum of A level secondary education. minimum of 0 level secondary education.
t Currently optional. § Increased in 1972
to
9 years.
The past decade has also witnessed the firm establishof a rural health service. The basic plan calls for one health unit for every 50,000 rural population, the unit being made up of one main health centre, four health sub centres, and 20 midwife stations (fig. 1). By the end of 1970, a total of 44 main health centres, 180 health subcentres, and 943 midwife stations had become operational. This rapid growth of the rural health services has created a great demand for health staff of all categoriesprofessional ment
(e.g., doctors); paramedical (e.g., nurses, hospital assistants, public health inspectors, and dispensers); and auxiliary (e.g., assistant nurses, midwives, and publichealth overseers). DISTRIBUTION, TRAINING,
AND
COST OF STAFF
Although the present ratio of doctors to population is 1 to 5000 in West Malaysia, the distribution is uneven. In urban areas the ratio is 1 to 1500, while that in the rural areas is 1 to 25,000, the distribution of paramedicals being similarly uneven. are not only scarce but also and require long and rigorous expensive, training. In 1969, only 1-4% of persons aged 19-21 years were enrolled in universities in West Malaysia. Although not as acute, there is a current shortage of paramedicals, particularly nurses. Paramedicals are recruited from school-leavers who have completed 0 level secondary
Professionals
Fig.
1-A rural health
unit, designed
to serve
50,000 people, and
a
hospital.
984
(fig. 3), with 1 professional, 13 paramedicals, and 45 auxiliaries, supported by 30 semiskilled/unskilled staff, for each rural health unit designed to serve 50,000 rural people.4 The most peripheral members of the rural health unit would be the 20 (singleauxiliary) midwives located at the 20 midwife stations of each unit, while the other auxiliaries consisting of the 15 assistant nurses, the 5 public-health overseers, and the remaining 5 midwives would be located in the main centre and four subcentres, together with the paramedicals, the doctor being based in the main health centre. This tiered pyramidal system, with its heavy reliance on the auxiliary and based on the principle of delegation to the lesser trained according to his abilities, has permitted the rapid establishment of the rural health services to cover over a third of the rural population in the short space of 15 years. At independence in 1957, the infant mortality-rate was 75-5 per 1000 live births, the toddler mortality-rate stood at 10-7 per 1000 toddlers, and the maternal mortalityrate was 3-2 per 1000 live births. By 1970 these rates had fallen to 40-8, 4-2, and 1-48, respectively.
purpose
Fig. 2-Average cost per day of staff rendering direct patient and health
care.
education (see accompanying table), and undergo training varying from 32 months to 63 months. In 1969, only 20-8% of the age-group 15-16 years were enrolled for 0 level secondary education. On the other hand, auxiliaries are recruited from those with 7-9 years of basic education, and, in 1969, 55-8% of the age-group 12-14 years were enrolled for such an education.1 Professionals are expensive to employ as well as to
The Indigenous Midwife Delegation can also extend from the trained midwife to the indigenous midwife (bidan kampong), with whom a working partnership can be cultivated. In 1970 of births indigenous midwives attended 32% registered in West Malaysia. For a number of years now, a simple course of training has been conducted on an experimental scale. The aim is to teach indigenous
In
Malaysia, paramedicals cost 40-82% less, cost 75-88% less than the doctor per working day (fig. 2). Not only do professionals demand high salaries, but the requisite professional and social environment has also to be supplied.2This can be provided in the major towns but not in the rural areas. produce.
while auxiliaries
midwives simple hygiene,
to recognise danger signals indicating a need for medical referral, and to participate in the family-planning programme. With the coming into force, in 1971, of the Midwives Act 1966, further regulating the practice of midwifery, indigenous midwives who had attended women during childbirth
THE AUXILIARY IN THE RURAL AREAS
for 2 years before enforcement of the Act have been permitted to register as legitimate midwives and have been placed under the supervision of the health authorities. It is envisaged that training courses will now be extended to cover all these indigenous midwives.
It is uneconomic to employ highly trained personnel in work which auxiliaries are capable of performing. Further, there is a need for trained persons who can carry out simple technical procedures that do not necessarily require the attention of qualified doctors.s An absolute dependence upon fully trained professional personnel will severely handicap implementation of health programmes in developing countries. Thus from the outset it was decided that a tiered system would be used to staff the rural health unit in Malaysia
Fig. 3-Staff pattern
in
a
rural health unit in the form of
THE FUTURE
In response
a
skill
pyramid.
urgent needs, a new auxiliary, the junior laboratory assistant, has lately emerged to take his place in the rural health unit. Demands created by the rapid establishment of rural
to
health services are sometimes best met by the training of large numbers of single-purpose workers such as the (auxiliary) midwife of Malaysia. However, single-purpose training is recognised as a temporary measure even though such auxiliaries may serve for several years. As sociocultural change occurs, and as expectations alter, such single-purpose workers should be retrained to meet new challenges. In Malaysia, plans are now being formulated to retrain the single-purpose
985
midwife in child health and nursing, and to give all assistant nurses midwifery training (currently optional) in order to equip these two auxiliaries for their new roles as multipurpose community nurse-midwives. Whatever changes may evolve with time, the experience of developed countries has shown that the need for auxiliaries will not diminish with the growth On the contrary, the of professional personnel. demand will continue and even increase, especially in developing countries. REFERENCES
1. Chee, H. Y. in Proceedings of the Second National Seminar on General Consequences of Population Growth, National Family Planning Board, Malaysia. Kuala Lumpur, 1970. 2. Fendall, N. R. E. Israel J. med. Sci. 1968, 4, 614. 3. Wld Hlth Org. tech. Rep. Ser. 1961, no. 212. 4. Jayesuria, L. W. A Review of the Rural Health Services in West Malaysia. Ministry of Health, Kuala Lumpur, 1967. 5. Malaysia. Midwives Act 1966.
Occasional
Survey
HEPATITIS-B ANTIGEN AND SAFETY IN PATHOLOGY LABORATORIES D. WATSON Area Laboratory,
I. L. CHRYSTIE J. BERTRAND
D. J. LANGLEY Edward VII Hospital, King Windsor
M. N. ISLAM J. E. BANATVALA
Department of Virology, Hospital, London SE1
St. Thomas’
possible, significantly assisting the clinical diagnosis. In one area laboratory, immune radiometry of sera from 400 patients and staff over a six-month period revealed only 2 sera with detectable H.B.A.1 At the same time several sera being distributed for qualitycontrol purposes were found to contain H.B.A. Because of this we have surveyed blood-serum products that are frequently used in pathology laboratories. METHODS
Products Tested These were 48 different lyophilised sera manufactured for control of precision and repeatability; also 38 similar commercial sera available for diagnostic purposes or standardisation of clinical analyses, which included 9 sera used for detection of blood-groups or antigens and 7 pure powders used for standardisation of protein analyses (all derived from pooled human plasma). In addition, there were 9 bovine-derived sera: ’ Precinorn E107 ’ and Precipath E104’ (Boehringer);’Lab-Trol 40F ’, ’Path-Trol 64AA ’, ’Enza-Trol 23TD ’, ’Choles-Trol ’ CTD309, and ’C.P.K.’ control 26 (Dade);’Wellcomtrol’assayed K4881, ’Wellcomtrol’ unassayed 2581 (Wellcome Reagents); and 4 horse lyophilised sera:Seronorm 113 ’ (Nyegaard/ B.D.H.); Control HA90BD and’Equitrol HA94 ’ (Tissue Culture Services, Slough); and ’H.C.S.’ (h-PL) (human placental lactogen) standard (Pharmacia). The maker’s recommended volume of reconstituting fluid-usually distilled water-was added to the vial containing lyophilised serum. In the case of the protein powders, approximately 4% w/v aqueous solutions were prepared for testing.
Immune radiometry (I.R.).- The method of Ling and Overby 2 was used. The two reagents required, Australia-antibodycoated tubes, 125I-Iabelled antibody together with 2M tris " (hydroxymethyl aminomethane) buffer concentrate, and a control solution containing H.B.A., are supplied by Abbott Laboratories as a kit (’Ausria-125 ’). The mean negative control count multiplied by 2-3 was regarded as a cut-off value. An expression of antigen strength is the ratio of the test count to the negative control count, and further quantitation is achieved by plotting this test-count/control-count ratio against concentrations of purified H.B.A. (Abbott). An experiment was undertaken to test the effect of serial dilution of an H.B.A.-containing commercial serum on the H.B.A. concentration measurable by this method. "
An
Summary
Australia-antigen screening
survey
carried out on 99 commercial blood products used in clinical-chemistry and hæmatology laboratories. 72% (35 of 48) of the lyophilised human sera used for quality control and distributed was
by eight American and one European companies contained the hepatitis-virus-B antigen (H.B.A.), one notable exception being eight sera from Technicon Instruments Corporation which were all H.B.A. negative. 36% (13 of 35) of other human-serumderived products used for diagnostic and standardisation purposes were also H.B.A. positive. A comparison of procedures for the detection and estimation of H.B.A. indicated that the methods recommended by an N.H.S. advisory group are too insensitive, yielding negative findings with potentially infective material. Manufacturers and hospital laboratories must be made aware that batches of such products should be regarded as high-risk specimens until more satisfactory screening procedures can be generally adopted. INTRODUCTION
BOTH
hepatitis (homologous serum jaundice, post-transfusion hepatitis, type-B viral hepatitis) and serum
infectious (type A) hepatitis are serious public-health hazards among those who handle blood or blood products. Biochemical tests to aid their differential diagnosis from non-parenchymatous liver disease (intra and extra hepatic obstruction) have long been used. However, routine detection of the hepatitisvirus-B antigen (H.B.A.) (and antibody) has become
Immune electron microscopy (I.E.M.).-Sera were incubated with anti-H.B.A. rabbit antibody (Hoechst Pharmaceuticals) according to the method described by Almeida and Waterson.3
Complement fixation (c.F.).-This was carried out as described by Taylor,4using three units of complement and four units of horse anti-hepatitis-B serum (Wellcome) at its optimum dilution and overnight fixation at 4°C. Immunoelectro-osmophoresis.-This test (i.E.O.P.; electroprecipitin ; counter-electrophoresis) was conducted using rabbit antiserum (Spectra Biologicals).5,G Tests were read without staining after seventy minutes’ electrophoresis. .HcsMM.g/MtMMfK’M.—Passive hacmagglutination (P.H.A.) was used for the detection of H.B.A. antibody and hsemagglutination inhibition (H.I.) for the detection of the H.B.A. Tests carried out according to a modification of the method Vyas and Shulmanin which 2-5 mM chromic chloride was used to couple the antibody to the erythrocytes; six H.B.A. units of rabbit antibody were used for H.I. tests, and to enable satisfactory settling of erythrocytes, normal human serum (blood-group AB at a dilution of 1/64) was used in were
of
the diluent.