Infectious Hepatitis

Evidence for Two Distinctive Clinical, Epidemiological,

and Immunological Types of Infection
Saul Krugman, MD, Joan P. Giles, MD, and Jack Hammond, MD

The identification of two types of infectious hepatitis epidemiologïcal, and immunological types of infec¬
with distinctive clinical, epidemiological, and immunolog- tious hepatitis.
ical features provided an explanation for the occurrence The nature of the endemic situation at the Wil-
of second attacks of the disease. One type resembled lowbrook State School has been described in detail
classical infectious hepatitis (IH); it was characterized in previous reports.1'3 Briefly, infectious hepatitis
by an incubation period of 30 to 38 days, a relatively was first noticed among Willowbrook patients as
short period of abnormal serum transaminase activity early as 1949. From 1949 to 1963 the patient popu¬
(3 to 19 days), a consistently abnormal thymol turbidity, lation increased from a mere 200 to over 6,000. As
and a high degree of contagion. The other type resembled the population increased and new susceptible chil¬
serum hepatitis (SH); it was characterized by a longer dren were admitted, hepatitis found a continuous
incubation period (41 to 108 days), a longer period of foothold. Attempts to relieve overcrowding have now
abnormal transaminase activity (35 to 200 days) and a reduced this population to approximately 5,400
relatively normal thymol turbidity. Contrary to commonly mentally retarded patients, predominantly children,
accepted concepts, the SH type was moderately conta- who are distributed among 24 buildings. The con¬
gious. Patients with IH type were later proved to be stant admission of many susceptible children and the
immune to the same type. Patients with the SH type were natural transmission of the disease via the intes¬
not immune to the IH type infection.
tinal-oral route have been responsible for the con¬
tinuing endemic situation. Many of the patients are
InfectioIsland,
Staten
us hepatitis
NY,
has been recognized as an en¬
demic disease at the Willowbrook State School,
since 1953. As a result of this
For editorial comment see page 406.
endemic environment, 1,153 cases of infectious hepa¬
titis with jaundice were observed to have been trans¬ incapable of being toilet trained and prone to put
mitted by natural contact in this institution during everything that they pick up into their mouths. This
intensifies the problem of control. Under the chronic
the past 12 years. Second attacks with jaundice circumstance of multiple and repeated natural ex¬
have occurred in 63 patients or 5.5% of this group. posure, it has been shown that most newly admitted
In most instances the second attack of jaundice oc¬ children become infected within the first 6 to 12
curred within one year but occasionally as late as months of residence in the institution.
four and seven years after the first attack. One pos¬ Prior experience indicated that y-globulin did not
sible explanation for second attacks would be the
existence of multiple types of infectious hepatitis prevent hepatitis infection; it attenuated the dis¬
ease. Eleven separate dosage trials with y-globulin
virus, immunologically separate and distinct. Ex¬ have been undertaken since 1956 in an attempt to
amples of this phenomenon have been observed in reduce the number of clinical cases of infectious
enterovirus, adenovirus, and myxovirus infections. hepatitis in the institution. The direct measurable
The studies reported in this communication provide result of these programs was a reduction of ap¬
evidence for the presence of two distinctive clinical,
proximately 85% of icteric hepatitis among patients
From the Department of Pediatrics, New York University and employees at Willowbrook. With the realiza¬
School of Medicine, New York (Drs. Krugman and Giles), and tion that subclinical cases persisted and were con¬
Willowbrook State School, Staten Island, NY (Dr. Hammond).
Dr. Giles is recipient of the New York City Health Research tagious, elimination of the disease could not be
Council Career Scientist award.
Read in part before the Pan American Health Organization\x=req-\
accomplished. In the absence of an effective vaccine,
World Health Organization International Conference on Vaccines the study on the natural history of infectious hepa¬
Against Viral and Rickettsial Diseases of Man, Washington, DC, titis in this institution was therefore considered an
Nov 11, 1966, and before the 77th annual meeting of the Amer-
ican Pediatric Society. Atlantic City, NJ, April 27. 1967. important step toward better understanding and
Reprint requests to 550 First Ave, New York 10016 (Dr. Krug- future control of this infection. The benefits of such
man). a program to the entire institution were obvious. It

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remained then to assess the risks and the benefits (5) that the investigator, or investigating com¬
to the children who would be active participants in mittee, or any scientifically or medically qualified
the study. person associated with him or the committee should
The decision to propose the controlled infection of be free to discontinue the experiment if in his or
a small number of newly admitted children was their judgment it may, if continued, be harmful to
based on the following considerations: the subject of the experiment; (6) that any risk to
1. It was well recognized that infectious hepatitis which the subject of an experiment may be exposed
was a mild and relatively benign disease in children should be carefully assessed in terms of direct benefit
as compared with adults; most cases were anicteric to himself or indirect benefit to others, on the as¬
and asymptomatic. Experience at Willowbrook sumption that the risks have been explained to, and
indicated that the disease observed at this institu¬ freely accepted by, the subject of the experiment.
tion was especially mild. Consequently, only the
Willowbrook strains of infectious hepatitis virus Materials and Methods
would be used for the study. The children in the various study groups were 3
2. The study group would include only children to 10 years of age. They were admitted directly to a
whose parents gave written consent after being in¬ special isolation facility capable of housing up to 16
formed of the details, potential risks, and potential children. The number of children included in each
benefits of the investigation. study generally ranged between 6 and 14. They had
3. The study would be carried out in a special no contact with the rest of the institution and were
isolation unit with special medical and nursing per¬ cared for by physicians, nurses, and attendants who
sonnel to provide close observation and optimum had minimal contact with other patients and per¬
care. Thus, these children would be protected from sonnel.
other endemic diseases in the institution, such as Source of Hepatitis Virus.—Blood serum from pa¬
shigellosis, parasitic infections, respiratory infec¬ tients in the Willowbrook study provided the source
tions, and other infectious diseases. Experience has of infectious virus. The material was tested for
indicated that the children in the special isolation safety to rule out the presence of adventitious bac¬
unit were subjected to less risk than the children who terial viral, or mycotic agents. The serum was in¬
were admitted directly to the institutional wards. oculated into suckling mice and into the following
4. It is important to emphasize that the studies tissue cultures: rhesus monkey kidney, human em¬
were to be carried out at the Willowbrook State bryonic lung fibroblasts, and the WISH strain of
School because of the local endemic situation, and continuous human amnion cells. No cytopathic
not because the children were mentally retarded. changes were seen in tissue cultures and no illness
Observations on approximately 250 children who was observed in the animals.
acquired artificially induced hepatitis in the Wil¬ Biochemical Tests of Liver Function.—In addition
lowbrook study since 1956 revealed that the experi¬ to careful clinical observation for presence of jaun¬
mental disease was generally milder than the ob¬ dice, hepatomegaly, and other manifestations of
served natural infection. In fact, many cases would hepatitis, tests of the following were performed at
have gone unrecognized if it had not been for careful periodic intervals: serum bilirubin, thymol turbidity,
daily observation and serial biochemical tests of serum glutamic oxalacetic transaminase (SGOT)
liver function. and bilirubin in the urine. Blood was obtained be¬
The studies were reviewed and sanctioned by the fore exposure and at weekly intervals or more often
University Committee on Human Experimentation, thereafter. The following methods were employed:
by the New York State Department of Mental Hy¬ serum bilirubin( Malloy and Evelyn5), thymol tur¬
giene, and by the Armed Forces Epidemiological bidity (Maclagan8) and SGOT (Karmen7). A re¬
Board. The Willowbrook studies have been con¬ sult was considered abnormal if the serum bilirubin
ducted in accordance with the World Medical Asso¬ value was more than 1.0 mg/100 ml; the thymol
ciation's Draft Code of Ethics on Human Experi¬ turbidity more than 6 units, and for the purpose of
mentation.4 The guidelines which were adopted for the present study if the SGOT was 100 units or
the study at its inception in 1956 conform with the more.
following general principles of the Code of Ethics: Criteria for Diagnosis of Hepatitis.-The occur¬
(1) that where children are to be the subject of an rence of clinical jaundice associated with an abnor¬
experiment, the nature, the reason, and risks of it mal serum bilirubin and an abnormal SGOT was re¬
should be fully explained to their parents or lawful quired for a diagnosis of hepatitis with jaundice.
guardians, who should have complete freedom to The diagnosis of hepatitis without jaundice was
make a decision on behalf of the children; (2) that reserved for cases in which the serum bilirubin value
children in institutions and not under the care of was less than 1.0 mg/100 ml but in which a cre¬
relatives should not be the subject of human experi¬ scendo-like rise in SGOT activity exceeded 100
ment; (3) that the experiment should be conducted units.
only by scientifically qualified persons and under the Definition of Incubation Period.—The method of
supervision of a qualified medical man; (4) that determining the incubation period of infectious hep¬
during the course of the experiment the subject of atitis has varied in many studies. Most often, it has
it should be free to withdraw from it at any time; been measured as the number of days between ex-

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posure and either onset of symptoms or onset of WILLOWBROOK SERUM POOL No.5-l.OML ORALLY CONTROLS
jaundice. It is well known that jaundice may occur
as early as two days or as late as two weeks after
-J
I 1 1 I J I IITT
the first sign of illness. Moreover, experience at Wil¬ <
30-35 33-47
OELH
30-44 35-44 33-54 36-44 51-58 51-68 58-75 61 51
lowbrook indicated that most cases of infectious (5801(580) I (890) (11201(6601 (670) (550) (9981(1000) -
-
(631(98)
hepatitis were anicteric and asymptomatic. Conse¬ cc
I II * II
quently, under the conditions of the present study 125-330+ 97-154
(1460) (700)
the incubation period was usually defined as the H0F. RED. NEL. MAC. SCH. CHA. MAS. WAC. MIR. CRU. MAN. WIL. GOR.
number of days between exposure and first evidence
of abnormal serum transaminase activity as indi¬ (550) (1601(900)
-
(6601(1680)1980) -

cated by a SGOT level above 100 units. <

-
82-146 70-87 70-102 66-96+ -
K)2-I47t 38-56
The evidence for the presence of two types of in¬ ce
OO 7
O0O0IIOOQI
- -
- -

fectious hepatitis was accumulated from a series of

seven separate trials which were carried out during
fCONTROLS
i t i i i i i i i i i t íWILLOWBROOK SERUM POOL No.5-0.25ML I.M.
the period from September 1964 to January 1967.
First Trial | HEPATITIS WITH JAUNDICE Q] POSSIBLE ANICTERIC HEPATITIS

Willowbrook serum pool No. 5 (WSP-5) was used 0 ANICTERIC HEPATITIS O N0 APPARENT DISEASE

for the first trial. It was prepared from specimens 1. First trial, occurrence of first attack of hepatitis after
obtained three to seven days before onset of jaun¬ subjects were fed Willowbrook serum pool No. 5
(WSP-5). Second trial, occurrence of second attacks of
dice in 27 Willowbrook study patients. On Sept. 23, hepatitis in same subjects following inoculation of
1964, WSP-5 was fed to 11 of 13 newly admitted WSP-5 six months later. First number indicates first
day SGOT exceeded 100 units/ml; second number,
subjects in a dose of 1.0 ml. Two children served as first day SGOT declined to levels below 109 units; num¬
controls. All subjects were intimately exposed to bers in parentheses, peak SGOT levels.
each other but were isolated from other Willow¬
brook patients. in most patients during the first trial; it was much
Results.—As indicated in Fig 1, oral administra¬ longer (17 to 64 days) during the second trial. These
tion of WSP-5 was followed by hepatitis in ten of 11 findings suggested the possibility that the two at¬
subjects. The incubation periods ranged between tacks of hepatitis were caused by two different
30 and 36 days in six children, and between 51 and viruses.
58 days in three; in one child evidence of hepatitis During the course of the first two trials, serial
was first detectable on the 125th day. Patient Mac samples of serum were obtained before and after
had a spontaneous second attack of hepatitis on the onset of first and second attacks of hepatitis in indi¬
97th day, 67 days after onset of the first attack. vidual subjects. This material was stored in the deep
At least one of the two unfed controls may have had freeze at —20 C. Serum specimens from subject
possible anicteric hepatitis. Jaundice was observed Mir were selected for special study. It was postu-
in six of ten subjects with hepatitis.
WILLOWBROOK SERUM POOL No.5-l.OML ORALLY ON 9/23/64
Second Trial
-{-
The second trial was undertaken to study the m ATTACK MIR.B FIRST
problem of second attacks of hepatitis. On March I J-l TOJ-6 DAY SERUM IMS-l)0.l-0.2 ML Ü CONTROL GROUP
jp i
26, 1965, WSP-5 was given to ten of 13 subjects H ö ói Ó â ÈÔ ÈÉÈÈ
who had participated in the first trial six months 31-40 34-53 37-40 37-46 38-4946-60 53-63 46-49 60-70 66-78 70-81 70-78 85-91+
(1280) (3401 (2701 (560) (5601(1380) (840) (156) (1240) (240) (1880) (640) (420)
previously. The dose was 0.25 ml intramuscularly. CLA JEN SHER MCD WJO PAR AXE SHE POR HOR MAR WJA RAM ALL
Three additional subjects were uninoculated con¬
WILLOWBROOK SERUM POOL No. 5-0.25 ML INTRAMUSCULARLY ON 3/26/65
trols. All 13 subjects were isolated from other Wil¬
lowbrook patients from the beginning of the first ï
m MIR.B SECOND ATTACK
trial until the termination of the second trial.
Results.—As indicated in Fig 1, hepatitis was ob¬ I J-5DAY SERUM(M5-2)0,25MLI.M. I | CONTROL GROUP I
served in six of ten subjects who were inoculated
with WSP-5. The incubation periods ranged be¬
í\ b à à \h à à äöo
41-162 45-246 50-113 55-146 59162 59-181 69-104
(440) (1500) (680) (270) (4201 (620) (1380)
ààóó
155-215 231-265
(220) (950)
o
tween 38 and 102 days. The occurrence of hepatitis PEL HAM CER CIL BIS RHO LAW NE* SUT CEN MED GOM RUM TOR
in four subjects (Sch, Mas, Wac, and Mir) repre¬
sented second attacks.
As indicated in Fig 1, the following differences
^-HEPATITIS WITH JAUNDICE Q-ANICTERIC HEPATITIS O"N0 »PWENT DISEASE
were apparent when the results of the first two trials 2. Third trial, occurrence of hepatitis in subjects who
received serum (MS-1) obtained from patient Mir during
were compared: (1) During the first attack of hepa¬ first trial. Note onset of hepatitis after relatively short
titis in four subjects (Sch, Mas, Wac, and Mir) the incubation period: relatively short period of abnormal
incubation period ranged between 35 and 51 days; it transaminase activity; and high attack rate in control
group. Fourth trial, occurrence of hepatitis in subjects
was longer during the second attack, ranging be¬ who received serum (MS-2) from patient Mir during
tween 66 and 82 days. (2) Duration of abnormal second trial. Note longer incubation pericd, longer
SGOT activity was relatively short (5 to 17 days) period of abnormal transaminase activity, and contact
infection in two of five control subjects.

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 serum was given intramuscularly to eight subjects;
SERUM- MS-1
PATIENT-MCO-5 yrs
the dose was 0.1 to 0.2 ml. Six subjects were unin-
oculated controls. All children were intimately ex¬
posed to each other during the course of the trial.
Results.—The results of the third trial are shown
inFig 2 and Table 1. Hepatitis was observed in seven
10 20 30 40 50 60 70 60 90 100 120 140
NUMBER OF DAYS AFTER INOCULATION SERUM
of eight subjects who were inoculated with MS-1
serum; the incubation periods ranged between 31
and 53 days. A transient jaundice with a slight ele¬
vation of serum bilirubin (1.4 mg/100 ml) was
present for one day in one patient, subject McD.
The remaining six children had anicteric hepatitis.
The results of serial biochemical tests of liver func¬
160
tion in the seven inoculated children infected with
10 20 30 40 50 60 70 60 90 100 120 140
NUMBER OF DAYS AFTER INOCULATION OF SERUM MS-1 serum are listed in Table 1 which shows (1)
3. Pattern of serum transaminase (SGOT) and thymol the spiking rise and precipitous fall in SGOT ac¬
turbidity (TT) activity response after inoculation of
serum from first attack (MS-1) and second attack
tivity and (2) the presence of abnormal thymol
(MS-2). Note spiking rise and precipitous fall of SGOT turbidity in all seven patients.
and abnormal TT activity following MS-1 infeciion. In All six subjects in the uninoculated, intimately
contrast, note gradual rise and prolongation of SGOT exposed control group contracted hepatitis 46 to
activity and normal TT following MS-2 infection. 85 days after the beginning of the third trial. Jaun¬
dice was observed in only one of the six control
lated that blood obtained during the week prior to children (Hor). The observation of contact infec¬
onset of the first attack of jaundice should contain tion after 46 days indicated that hepatitis caused
the virus responsible for the first attack. It was also
postulated that blood obtained six months later by MS-1 serum had an incubation period of 31 to
should contain neutralizing antibody against the 38 days.
virus responsible for the first attack, and consequent¬ Fourth Trial
ly, if the second attack serum were infectious, it Fourteen newly admitted children participated
would suggest the presence of an immunologically
distinct type of virus. in the fourth trial. On Aug 24, 1965, MS-2 serum
The serum specimens obtained from subject Mir was given intramuscularly to nine subjects; the dose
was 0.25 ml. The specimen of MS-2 serum was ob¬
prior to the first attack were pooled and designated tained five days before onset of the second attack of
MS-1. This material was used for the third trial. The
serum specimens from the same subject immediate¬ jaundice. Five subjects were uninoculated controls.

ly before the second attack were designated MS-2 All 14 children were intimately exposed to each
and were used for the fourth trial. other during the course of the trial.
Results.—As indicated in Fig 2 and Table 2, hepa¬
Third Trial titis was observed in seven of nine subjects who
Fourteen newly admitted subjects participated in were inoculated with MS-2 serum. The incubation
the third trial. On Nov 22, 1965, a pool of MS-1 periods ranged between 41 and 69 days. Jaundice

Table 1.—Serial Liver Function Tests in Seven Children Infected With MS-1 Hepatitis Serum
CLA JEN SHER MCD W JO PAR AXE
Day
After r
Exposure TT" SGOTt SGOT SGOT TT SGOT SGOT SGOT SGOT
16 26 2.5 26
0 4 _34_ 2.5 _14__ 19 <1.2 21 <1.2 j4.0_ 27
1.2 20 28 <lZ- 20 <\.2 16 1.8 27
10 2.7 27 _32_ 21
16 _28 4.2_ 42 3.5 18 <1.2 21 2.1 27_
22
42 2.1 42 1.8 26 2.7 20
22 2.7 _20 57_ 27 8.7
16
50 7.5 27 J.2_ 16 2.1 18 7.5
28 6.2 84_ _<1.2_
_

20 5.7 21 1.8 12 21 16
31_ 6.5 1,280
_ _2.1_ _40_ 4.5
34 8 310
13.7 3.2 24 2.1 14 4.2 10 6.5 20
35 12.5 120 _
12.5 _
160 24_ 17
37 11.2 170 15.5 340 6.2 _?70_ 2.1 170 1.2 _86_ 2.1
40 14
40" 12.5^ 56 25_ 138^ 7.5 _84_ _7JL5_ 180 560 4.2
22 4.5 19
42 10 39_ 25_ J40 ñ.2_ 40 14.8 J60 7.5 420
1.2 20
6.5 22 91 10 34_ 21 75 6.7 J14 128
46 _48_ 7.7 "27 18 84 5.5 51 750 21
49 6.2 29 27 126
51_ J,380^
52 7.5 _940^
39 56 9.2 740 11 840
153_
55
21 64 8.5 50 17^
13 48
13.4
13 600
56 49 22.2 34 8.5 41 11.7 46 11 480 16 560
58 15 138_
L60_ 21_ 17.5 44 8.7 35 10.5^ 20 11.2 44 9.5 60 22 _106_
63 7 42 16.4 57 11 13 11.5 42 8.7 18 13 34 16.5 49

•Thymol turbidity, units.

¡Serum glutamic oxaloacetic transaminase, units/ml.

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occurred in one patient, Law, on the 83rd day, and thymol turbidity response is illustrated in Fig
14 days after first evidence of abnormal SGOT ac¬ 3. MS-1 infection in subject McD (third trial) is
tivity (> 100 units). The remaining six children characterized by a spiking rise in SGOT activity
had anicteric hepatitis. The results of serial tests followed by a rise in thymol turbidity. In contrast,
of liver function shown in Table 2 reveal a gradual MS-2 infection in patient Bis (fourth trial) is char¬
rise and a prolonged persistence of SGOT activity. acterized by a normal thymol turbidity and a
Thymol turbidity was normal in five of seven sub¬ gradual, prolonged rise in SGOT activity.
jects. The results of the first and third trials clearly
Anicteric hepatitis was observed in two of the demonstrated that infectious hepatitis virus MS-1
five uninoculated control subjects, 155 and 231 type was infectious by mouth and the disease was
days after the beginning of the fourth trial. Hepa¬ highly contagious. The results of the fourth trial
titis occurred in contact Cen, 86 days after onset indicated that infectious hepatitis MS-2 type was
of the disease in subject Law. Hepatitis in contact less contagious but it did spread to susceptible con¬
Med occurred 76 days after onset of hepatitis in tacts. The fifth and sixth trials were designed to
contact Cen. test the infectivity of MS-2 serum by mouth. The
A comparison of the results of the third and sera to be tested were obtained from subjects Ham
fourth trials revealed the following differences: (1) and Pel who had a typical MS-2 type infection
Incubation period ranged from 31 to 38 days (mean (fourth trial).
of 35 days) following MS-1 infection, as compared
Fifth Trial
with 41 to 69 days (mean of 54 days) following
MS-2 infection. (2) Abnormal serum transaminase Nine newly admitted children participated in the
activity was relatively short (3 to 19 days) fol¬ fifth trial. On Feb 17, 1966, MS-2 type serum ob¬
lowing MS-1 infection and relatively long (35 to tained from subject Ham was given to six subjects.
200 days) after MS-2 infection. (3) Thymol tur¬ The dose was 0.5 ml by mouth; three children were
bidity was consistently abnormal after MS-1 infec¬ unfed controls. One week later the six children re¬
tion; it was frequently normal after MS-2 infection. ceived y-globulin, 0.01 ml per pound of body weight
(4) Contagion—MS-1 infection was highly conta¬ intramuscularly. The use of y-globulin was a precau¬
gious for all six presumably susceptible contacts; tionary measure because of limited experience with
MS-2 infection was less contagious, spreading to MS-2 type of infectious hepatitis virus.
only two of five presumably susceptible contacts. Results.—The results of the fifth trial are shown
The striking contrast in the pattern of SGOT in Fig 4. Anicteric hepatitis was observed in five of

Table 2.—Serial Liver Function Tests in Seven Children Infected With MS-2 Hepatitis Serum
CIL BIS RHO LAW

189
"Thymol turbidity, units.
¡Serum glutamic oxaloacetic transaminase, units/ml.

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 "MS-2" SERUM FR0M"HAM"-0.5ML ORALLY+GG 0.01 ML/LB I WEEK LATER was compatible with a MS-2 type of infection.
The previous six trials provided evidence for two

£ S 5 5 S i
64-70
(180)
96-133
(440)
117-161
(490)
133-161+
(840)
209-222+
1360)
types of infectious hepatitis with distinctive clini¬
cal and epidemiological features. The seventh trial
was designed to study the immunological aspects
WOO CAS VEL KAR WIL KET of the disease following MS-1 type infection (third
trial) and MS-2 type infection (fourth trial).
"MS-2"SERUM FR0M"HAM"AND"PEL"0.5ML ORALLY-NO GAMMA GLOBULIN Seventh Trial
The sixteen subjects who participated in the
¿r "ir "h it "ir
88-115
(740)
95-157
11320)
104-167
(980)
104-115
(140)
108-179
(1260)
o seventh trial included eight children from the
third trial and eight children from the fourth trial.
The entire group was isolated from other institu¬
LOP LEN HAR SEO OAV DEA
tional patients during the entire period of the study.
[«"I ANICTERIC HEPATITIS On March 28, 1966, four months after the third
trial and seven months after the fourth trial, all
4. Fifth and sixth trials, oral administration of MS-2
serum followed by anicteric hepatitis in ten of 12 sub¬ 16 subjects were inoculated with infectious hepa¬
jects after long incubation periods. First number indi¬ titis serum, MS-1 type; the dose was 0.2 ml. intra¬
cates first day that SGOT exceeded 100 units/ml; sec¬
ond number, first day the SGOT declined to levels below muscularly.
100 units; numbers in parentheses, peak SGOT levels. Results.—Evidence for homologous immunity fol¬
lowing MS-1 infection is presented in Fig 5. The
six presumably susceptible subjects. The incubation initial inoculation of MS-1 serum on Nov 22, 1965,
periods ranged between 64 and 209 days. The dura¬ had been followed by infectious hepatitis in seven
tion of abnormal SGOT activity was prolonged and of eight subjects; the pattern of serum transaminase
the thymol turbidity response was normal in three and thymol turbidity activity was typical of MS-1
of five subjects with hepatitis. All children were infection. Subsequent challenge with infectious MS-
clinically normal. They were asymptomatic and 1 serum on March 28, 1966, revealed no evidence
they gained weight. Hepatitis was not observed in of hepatitis with or without jaundice; all eight sub¬
the three children who were unfed controls. jects were immune.
Lack of heterologous immunity in subjects first
Sixth Trial infected with MS-2 virus is shown in Fig 6. The
The fifth trial indicated that infectious hepatitis initial inoculation of MS-2 serum on Aug 24, 1965,
virus MS-2 type was infective by mouth. It was was followed by infectious hepatitis in six of eight
considered important to confirm this observation. subjects; the pattern of transaminase and thymol
Accordingly, on May 27, 1966, MS-2 type serum turbidity activity was typical of MS-2 infection.
from subjects Ham and Pel was given to six pre¬ Subsequent challenge with infectious MS-1 serum
sumably susceptible newly admitted subjects; the on March 28, 1966, was followed by hepatitis in all
dose was 0.5 ml by mouth. Gamma globulin was eight subjects. The pattern of the SGOT and thymol
not administered. turbidity response in this second attack was char¬
Results.—As indicated in Fig 4, the results of the acteristic for MS-1 type of infection. Thus, inocu¬
sixth trial were similar to the fifth trial. Anicteric lation of MS-1 serum was followed by hepatitis in
asymptomatic hepatitis was observed in five of six five of six subjects who had a previous infection
subjects after prolonged incubation periods rang¬ caused by MS-2 serum (Fig 6). In contrast, the
ing between 88 and 108 days. The SGOT activity same MS-1 serum produced no evidence of infec¬
was prolonged and the thymol turbidity response tion in seven subjects who had a previous attack

RESULTS OF IH0CUHTI0N WITH MS-1 SEBUM 111/22/651 RESULTS OF CHALLENGE WITH MS-1 SERUM 13/28/66) RESULTS OF IH0CULATI0N WITH MS-2 SERUMI8/24/65I RESULTS OF CHALLEH6E WITH MS-1 SERU»(3/28/66)
ABNORMAL SHOT ftCTIVITT r,pE ABNORMAL SGOT ACTIVITY PEJK THYMOL TYPE ABNORMAL SGOT ACTIVITY PEiK IHru0L
TÏPE PEJ, r„YB0L OF PEAK LEVEL DURATION TURBIDITY OF PEAK LEVEL DURATION TURBIDITY
OF PEAK LEVEL DURATION TURBIDITY SUBJECT HEPATITIS UNITS/ML DAYS UNITS/ML HEPATITIS UNITS/ML DAYS UNITS/ML
SUBJECT HEPATITIS UNITS/ML DAYS UNITS/ML TYPE OF HEPATITIS

AXE H 840 10 22.0 O RHO B 620 122 5.5 1500 15 32.0

MAR H 240 12 13.5 O PEL H 440 121 8.0 H 830 15 15.5

MCD 560 9 21.0 O CER E 680 63 22.0 B 510 14 20.0

JEN B 340 19 27.0 O BIS B 420 103 5.0 O - -

SHR H 270 3 10.0 O HAM B 1500 200 7.5 H 1360 15 25.0

WJA H 1880 II 15.0 O MEO B 950 34 7.5 1040 17 40.0
WJ0 H 560 II 13.4 O SUT O - - -
B 380 14 15.7
SHE O - O G0M O - -
750 14 21.2
HEPATITIS WITH JAUNDICE H ANICTERIC HEPATITIS O N0NE HEPATITIS WITH JAUNDICE H ANICTERIC O N0NE
HEPATITIS

5. Evidence for homologous immunity following MS-1 6. Evidence for lack of heterologous immunity follow¬
hepatitis infection. ing MS-2 hepatitis infection.

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of hepatitis caused by MS-1 serum (Fig 5). These
observations indicate that the two types of hepatitis CLA-LOBÏ2]
virus are immunologically distinct. JEN-Häa
Comment SHE-§EÊ
MCD-137|42|46|
The data accumulated during the course of these
studies confirm the presence of two types of infec¬ L WJO
tious hepatitis in Willowbrook. In the series of
seven trials it has been possible to identify distinc¬
tive clinical, epidemiological, and immunological
features characteristic of each type of infection. The
two types of hepatitis were caused by two different
viruses, designated as MS-1 and MS-2. MS-1 virus
was derived from the serum of a patient during the
first attack of hepatitis; MS-2 virus was derived
from the serum of the same patient six months
later.
The disease associated with MS-1 virus infection 7. Comparison of incubation period and abnormal
SGOT activity following MS-1 and MS-2 hepatitis infec¬
is undoubtedly the classical type of infectious hepa¬ tion. Note relatively long incubation period, more pro¬
titis, a disease also known under the following longed period of abnormal SGOT activity following MS-2
aliases: infective hepatitis, IH hepatitis, virus A infection, also delay in onset of jaundice or peak SGOT
activity following MS-2 infection. First number indicates
hepatitis, and in former years, acute catarrhal jaun¬ time interval in days, from exposure to first increase in
SGOT above 100 units; black square, day of onset of
dice and epidemic jaundice. The disease associated
jaundice; white square, day of peak transaminase; last
with MS-2 virus infection resembles serum hepatitis number, first day the SGOT declined to levels below 100
which has also been referred to as homologous serum units.
jaundice, SH hepatitis, virus B hepatitis, post-
transfusion hepatitis, and postvaccinial hepatitis. A of MS-2 type of infection was longer following oral
comparison of the incubation period, thymol tur¬ exposure (sixth trial) than parenteral inoculation
bidity pattern, and epidemiological and immuno¬ (fourth trial).
logical aspects provides evidence supporting the re¬ Thymol Turbidity Pattern.—Reports by Neefe13
lationship of MS-1 to infectious hepatitis (IH) and and by Green" have indicated that the thymol tur¬
MS-2 to serum hepatitis (SH). bidity test is often negative in serum hepatitis.
Incubation Period.—The incubation period of in¬ Neefe stated that "In two small but closely com¬
fectious hepatitis has been reported to range be¬ parable groups of patients with induced virus IH
tween 15 and 50 days1,811; the mean is approxi¬ hepatitis and virus SH hepatitis, respectively, the
mately 30 to 35 days. In contrast, the incubation responses to the serum colloidal gold and the thy¬
period of serum hepatitis has been observed to be mol (turbidity and flocculation) tests were less in
much longer, generally ranging between 43 and
180 days with most cases occurring between 60 and
90 days.91112 In natural disease, especially infec¬
tious hepatitis, the limits of the incubation period
are often ill-defined because the precise time of
infection is unknown. Incubation periods follow¬
ing MS-1 and MS-2 types of infection are charted
in Fig 7. Two types of incubation period have been
recorded: (1) the interval between the time of ex¬
posure and first sign of hepatic involvement, as in¬
dicated by an increase in SGOT above 100 units/ml;
and (2) the interval between time of exposure and
peak SGOT or onset of jaundice. Experience at
Willowbrook has indicated that onset of jaundice
generally occurs at the time of peak transaminase MS-1
activity. As indicated in Fig 7, the incubation peri¬ MS-2
od following MS-1 infection was 31 to 42 days; (15.0) (8.5),
l4
-»-
the mean was 37 days. In contrast, MS-2 infection DATA FROM GREEN DATA FROM WBRK
occurred after an incubation period of 55 to 90 HEPATITIS STUDIES
days; the mean was 71 days. The similarity of MS-1 8. Comparison of peak thymol turbidity levels within
to IH and MS-2 to SH is obvious. two weeks after onset of jaundice in 19 patients with
The mode of transmission did not affect the in¬ infectious hepatitis (IH), 12 patients with serum hep¬
atitis (SH), 13 Willowbrook patients with infectious hep¬
cubation period of MS-1 type of infection; it was atitis (MS-1 type), and 23 Willowbrook patients with in¬
fectious hepatitis (MS-2 type). Note similarity in thymol
essentially the same following oral and parenteral turbidity response between IH and MS-1 and between
exposure. On the other hand, the incubation period SH and MS-2.

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degree and duration in the virus SH hepatitis than Although both types of virus were infective by
in the other group." Green described the thymol mouth, it was clear that MS-1 was more highly in¬
turbidity pattern in 12 cases of serum hepatitis and fectious than MS-2. During the course of the first
19 cases of infectious hepatitis. His data, charted in trial (Fig 1) the two viruses were inadvertently
Fig 8, support Neefe's observations. As indicated in fed as components of Willowbrook serum pool No.
Fig 8, the thymol turbidity test in serum hepatitis 5. Of ten subjects who acquired hepatitis, nine had
was relatively normal within the first two weeks a typical MS-1 or IH type of disease. In one pa¬
after onset of jaundice; the mean level was 4.5 Mac- tient, Nel, hepatitis occurred after an incubation
lagan units/ml. In contrast, it was increased sig¬ period of 125 days; the disease was a typical MS-2
nificantly in infectious hepatitis; the mean level type of infection. It is likely that patient Nel was
was 14.0 units. The data from the Willowbrook immune to IH before exposure to the serum pool.
studies, charted alongside Green's data in Fig 8, In four subjects (Sch, Mas, Wac, and Mir) the
highlight the striking similarity between IH and phenomenon of interference may have been re¬
MS-1 type hepatitis and SH and MS-2 type hep¬ sponsible for the occurrence of only one infection,
atitis. MS-1 type. In contrast, subject Mac had a double
SGOT Activity.—The striking contrast between infection caused by MS-1 after 30 days and MS-2
the SGOT pattern in MS-1 infection as compared after 97 days. There was no evidence of interference
with MS-2 infection is illustrated in Fig 3 and 7. in this patient.
In future studies it will be important to accumulate Immunological Aspects.—The immunological as¬
comparable data for typical cases of infectious hep¬ pects of MS-1 and IH hepatitis and MS-2 and SH
atitis and serum hepatitis. The spiking rise in SGOT hepatitis are essentially the same. Studies by Neefe
activity and its short duration in MS-1 infection and associates" and by Havens'" confirmed the exis¬
may be indicative of infectious hepatitis. On the tence of homologous immunity following IH and SH
other hand, serum hepatitis may be characterized hepatitis. In contrast, there was no evidence of cross
by a gradual rise and a prolongation of SGOT immunity between the two types of hepatitis. The
activity. same phenomenon has been observed following MS-
Epidemiological Aspects.—It is well recognized 1 and MS-2 infection (Fig 5 and 6).
that infectious hepatitis is a contagious disease and Clinical Aspects.—It was impossible to differen¬
that the most common mode of transmission is via tiate between the two types of hepatitis on the
the intestinal-oral route. Contact infection usually basis of clinical manifestations alone without the
occurs under conditions which favor crowding and aid of serial laboratory determinations. During the
close association. The evidence that MS-1 type of course of the seven trials, MS-1 type hepatitis was
hepatitis was highly contagious was presented in observed in 29 subjects; ten were jaundiced and 19
the third trial (Fig 2); all six contacts contracted were anicteric. MS-2 type hepatitis was observed
MS-1 type hepatitis after exposure to children with in 27 subjects; six were icteric and 21 anicteric.
MS-1 type of infection. This phenomenon is char¬ Jaundice in both groups was mild, the bilirubin
acteristic of IH type of hepatitis. value ranging between 1.0 and 3.0 mg/100 ml; it
The most widely accepted concept of the spread subsided after one to ten days, average of five
of serum hepatitis supports the parenteral mode of days for both groups. There was no correlation
transmission of infective blood or blood products. between persistence of abnormal enzyme activity
A limited number of trials in volunteers indicated and presence of clinical symptoms. The children
that serum hepatitis virus was not infective by were asymptomatic and gained weight in spite of
mouth." '5 The results of these studies suggested a prolonged elevation of SGOT. The weight gain
that serum hepatitis was rarely transmitted through during a 25-week period of observation was 0.9 to
personal contact. 3.6 kg (2 to 8 lb), average 2 kg (4.5 lb), for the
The observation that MS-2 type hepatitis was MS-1 group. During a 30-week period of observa¬
communicable (Fig 2) and infective by mouth tion, the weight gain in children in the MS-2 group
(Fig 4) would not be compatible with the prevail¬ ranged between 1.8 and 3.6 kg (4 and 8 lb), average
ing view that serum hepatitis is not contagious 2.7 kg (61b).
after intimate contact. On the other hand, these
findings would be compatible with reports by Find- Conclusions
lay and Martin,16 by Freeman,'7 and especially by The evidence presented in the foregoing discus¬
Mirick and Shank,18 who described an epidemic of
serum hepatitis in 272 persons who had been inocu¬ sion indicates that the two types of infectious hepa¬
lated with human plasma. The incubation period titis in Willowbrook are examples of infectious hepa¬
was long; it ranged from 49 to 125 days (average titis and serum hepatitis with distinctive clinical,
79 days). Thirty additional cases of serum hepatitis epidemiological, and immunological features. This
were observed in uninoculated personnel who had phenomenon is a logical explanation for the occur¬
been in intimate contact with plasma-inoculated rence of second attacks of hepatitis in this insti¬

personnel. The epidemiological aspects of MS-2 tution.

hepatitis in Willowbrook are similar to the epidemic This investigation was supported by a contract from the US
of serum hepatitis described by Mirick and Shank. Army Medical Research and Development Command, Department

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of the Army, under the sponsorship of the Commission on Viral State Commissioner of Mental Hygiene, and the following mem¬
Infections, Armed Forces Epidemiological Board, Office of the bers of the hepatitis research group: Olive Lattimer, RN, Florence
Surgeon General (contract DA-49-193-MD-2331). Goodfield, RN, Mrs. Alma Bertolini, and Mrs. Ruth Kirk. Philip
Assistance was provided by Alan D. Miller, MD, New York A. Brunell, MD, performed the safety tests.

References
1. Ward, R., et al: Infectious Hepatitis: Studies of Its Natural 11. Neefe, J.R.; Gellis, S.S.; and Stokes, J., Jr.: Homologous
History and Prevention, New Eng J Med 258: 407-416 (Feb 27) Serum Hepatitis and Infectious (Epidemic) Hepatitis: Studies in
1958. Volunteers Bearing on Immunological and Other Characteristics
2. Krugman, S., et al: Infectious Hepatitis: Detection of Virus of Etiological Agents, Amer J Med 1:3-22 (July) 1946.
During the Incubation Period and in Clinically Inapparent In- 12. MacCallum, F.O., and Bauer, D.J.: Homologous Serum
fection, New Eng J Med 261:729-734 (Oct 8) 1959. Jaundice: Transmission Experiments With Human Volunteers,
3. Krugman, S.; Ward, R.; and Giles, J.P.: The Natural History Lancet 1:622-627 (May 13) 1944.
of Infectious Hepatitis, Amer J Med 32:717-728 (May) 1962. 13. Neefe, J.R.: Recent Advances in Knowledge of "Virus Hep-
4. World Medical Association Draft Code of Ethics on Human atitis" Med Clin N Amer 30:1407-1443 (Nov) 1946.
Experimentation, Brit MJ 2:1119 (Oct 27) 1962. 14. Green, P.: Some Serochemical Differences Between Homol-
5. Malloy, H.T., and Evelyn, K.A.: Determination of Bilirubin ogous Serum Hepatitis and Infectious Hepatitis, Canad Med As-
With Photoelectric Colorimeter, J Biol Chem 119:481-490 (July) soc 63:365-368 (Oct) 1950.
1937. 15. MacCallum, F.O.: Transmission of Arsenotherapy Jaun-
6. Maclagan, N.F.: Thymol Turbidity Test: New Indicator of dice by Blood: Failure With Faeces and Nasopharyngeal Wash-
Liver Dysfunction, Brit J Exper Path 25:234-241 (Dec) 1944. ings, Lancet 1:342 (March 17) 1945.
7. Karmen, A.: Note on Spectrophotometric Assay of Glutamic\x=req-\ 16. Findley, G.M., and Martin, N.H.: Jaundice Following
Oxalacetic Transaminase in Human Blood Serum, J Clin Invest Yellow Fever Immunization, Lancet 1:678-680 (May 29) 1943.
34:126-133 (Jan) 1955. 17. Freeman, G.: Epidemiology and Incubation Period of
8. MacCallum, F.O., and Bradley, W.H.: Transmission of In- Jaundice Following Yellow Fever Vaccination, Amer J Trop Med
fective Hepatitis to Human Volunteers: Effect on Rheumatoid 26:15-32 (Jan) 1946.
Arthritis, Lancet 2:228 (Aug 12) 1944. 18. Mirick, G.S., and Shank, R.E.: An Epidemic of Serum Hep-
9. Paul, J.R., et al: Transmission Experiments in Serum Jaun- atitis Studies Under Controlled Conditions, Trans Amer Clin
dice and Infectious, Hepatitis, JAMA 128:911-915 (July 28) 1945. Climat Assoc 71:176-190, 1959.
10. Havens, W.P., Jr.: Period of Infectivity of Patients With 19. Havens, W.P., Jr.: Experiment in Cross Immunity Between
Experimentally Induced Infectious Hepatitis, J Exp Med 83:251\x=req-\ Infectious Hepatitis and Homologous Serum Jaundice, Proc Soc
258 (March) 1946. Exp Biol Med 59:148-150 (June) 1945.

It takes little
linguistic sophistication to be ready with
a spontaneous verdict on whether a particular English
word is of Romance or Teutonic origin. The verdict may
be wrong, but generally it is ready—spontaneously so. On
the other hand, whether a Latin word reached us by way
of French or directly is a matter on which we feel obliged
to consult a dictionary, except when its sojourn in French has left unmistakable
marks on its spelling and its pronunciation or both. That this latter matter, which
by rights ought to concern only the abstrusely learned, should have a bearing on
our spelling is most unfortunate. It does though.
Our suffixes "-nt" ("-nee") and "-ble" ("-bility") are preceded by "-a-" or
"-e-" and "-a-" or "-i-" reflecting a Latin pattern in which verbs in -are formed
-ant- and -abil- while verbs from other classes formed -ent- and -ibil-. Our pro¬
nunciation does not differentiate between the forms in -a- and those in -e- or -i-,
and in deciding which spelling to use in a given word we rely (to put it some¬
what mystically) on our awareness of Latin as Latin is alive in English.
This would be fine if there were not things like "resistant" (with "-a-") but
"resistible" (with "-i-"), while "existent" and "existible" (if we want such a
thing) do follow the pattern. Here is an English irregularity which hits no En¬
glish cause, only a French one, for French differentiates in pronunciation (and
spelling) between -ible and -able, but neither in pronunciation nor in spelling
(with some exceptions that have no bearing on our problem) between -ant and
-ent.
I can spell "existent" because I know English and am aware of the Latinity
that is alive in English. I can spell "resistant" because I know French or (since
that is no consistent guide) because I have learned it by rote. Actually, when I
am tired I can't spell it. When I am tired I have to look up "defendant" and "as¬
sistant" (but "consistent") and "ascendent" and "ascendant". . . .

This is a nuisance. If I were a dictator with full spelling-reform powers, I would

send all spelling-reformers to Siberia, though I myself would become guilty of
spelling reform to the extent of straightening out the "ent-ant" mess. While at it,
I would do a little repair work in the matter of the shaky distinction between
"-ceed" in "proceed" and "-cede" in "recede" (and possibly cut out one "m"
in "commence").
Alexander Gode, PhD

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