Usually, however, the command had been vaccinated recently, and the cases were of sporadic occurrence without secondary infection. Under such conditions no attention was paid to the matter except revaccination of contacts who recently had not been vaccinated successfully.

Individuals with smallpox were held in isolation until scaling was complete. The average duration of hospitalization of cases of smallpox during the World War was 29 days.

ETIOLOGY

No contributions were made to the elucidation of the etiology of smallpox by Army medical investigators during the World War.

SYMPTOMS

In general, the cases occurring in the United States were mild, in Siberia the infections were usually severe (hemorrhagic and confluent types), and in the Philippines and in France the disease was more severe than in the United States, but not so severe as in Siberia. Of 236 cases concerning which clinical histories are available for study, 166 (70 per cent) were admitted to hospital after the eruption was established. In a few instances patients with headache and fever remained in barracks for several days before smallpox was suspected. Headache was recorded in practically all cases. In 19 instances the records show that at no time did the patient feel ill. Backache was recorded in 42 per cent, and pains in the bones and joints in 33 per cent. Chills were noted in 32 per cent, nausea and vomiting in 21 per cent, and vertigo in 8 per cent. Abdominal pains were complained of in 22 cases (7 per cent), and in 2 of these the pain was located in the right inguinal region, was accompanied by rigidity of the abdominal muscles, and simulated appendicitis. Chest pains occurred in 3 per cent, and bronchitis frequently was noted. Three cases presented marked nervous symptoms, positive Kernig's sign and Babinski's reflex, stiffness of the neck muscles, diplopia, and convulsions. These cases so strongly simulated meningitis that lumbar puncture was performed. Pharyngitis was present in 91 cases (27 per cent).

This was a morbilliform smallpox rash was that of the body, especially the The usual induration or Scarring was

In but two cases was a prodromal rash noted. eruption simulating measles. Distribution of the usually seen; i. e., more commonly on exposed surfaces forehead, palms of the hands, and soles of the feet. "shotty" feel to the papules was recorded in nearly all cases. noted in but one case, which occurred in Siberia.

A review of

Elevation of temperature was not of constant occurrence. 139 clinical histories shows the temperature during the first week in hospital to have been afebrile in 50 cases (36 per cent); it ranged between 99° F. and 100° F. in 28 (20 per cent), and exceeded 100° F. in 61 cases (44 per cent).

In 87 cases, in which the eruption was more or less fully developed on admission to the hospital, 6 cases were in the macular; 4, maculopapular; 28, papular; 15, papulovesicular; 10, vesicular; 15, vesiculopustular; 22, pustular stage. It will be seen from the above statements that patients were admitted to hospital during all stages of the disease except incrustation. This apparent delay in sending cases to hospital was due principally to the fact that

many arrived in camp in the eruptive stage. This was not confined to camps in any one locality, but was common throughout the United States.

Secondary rise of temperature was practically always absent. Itching frequently was noted and often manifested itself early in the course of the disease. Albumin and casts in the urine were of frequent occurrence but evidently cleared up, as a diagnosis of nephritis was but rarely made.

The following extracts from clinical histories serve to illustrate some of the more important phases of the disease.31

A. H. R. (white), Pvt., Company 1, V. T. S., Camp Lee, Va. Length of service, three months. Vaccinated three times unsuccessfully in July and August, 1918. November 1, 1918, without prodromal symptoms, the eruption appeared on the forehead. Lesions so few in number that it was not until they became scattered all over the body, on November 5, that the patient was sent to hospital. Even then he did not feel ill. Temperature and pulse were normal during the evolution and decline of the eruption. Diagnosis: Smallpox On November 25, headache, backache, slight cough, and elevation of temperature were noted. Following these prodromes an eruption appeared which was diagnosed as chicken pox. Neither disease was severe and the patient was returned to duty after 41 days in

hospital.

G. K. (white), Pvt., B. H., Camp Dodge, Iowa. Length of service, three months. Successfully vaccinated February 28, 1918. On duty in isolation ward with smallpox cases. March 18, 1918, with prodromes, an eruption appeared on face, body, and extremities, thickest on forehead. When entered on sick report two days later (March 20) the eruption was described as "a number of small pustules on indurated bases." Temperature 104.4° F., but returned to normal on March 22, and 19 days after admission, desiccation being complete, the patient was discharged from the hospital to resume his duties as attendant in the smallpox ward.

A. L. H. (white), recruit unassigned, 163 D. B., Camp Dodge, Iowa. Length of service, one day. Never vaccinated. Several days before coming to camp the patient noticed an eruption on the forehead. He did not feel sick at the time. Smallpox was present in his home town. He was admitted to hospital on the day of his arrival in camp, May 28, 1918, because of a pustular eruption all over his body. He did not feel sick. On June 3 the pustules were dry and scaling had commenced. By June 8 scaling was complete, and the patient returned to duty on the 10th without any elevation of temperature during his stay in hospital. C. R. (colored), recruit unassigned, Camp Lee, Va. Length of service, one day. No record of previous vaccination. There was one case of smallpox in his home town at the time of his departure. He was taken sick April 10, 1918, while at home, with a severe headache and backache. There was a history of some fever, in bed four days, sore throat, and a few "bumps" on his face, April 15. He arrived at camp April 17, and was admitted to hospital with normal temperature and a discrete, shotlike, pustular eruption over the face, chest, abdomen, back, arms, and legs. There were a few pustules in the palms of hand and on the soles of feet; also slight umbilication. The eruption was diagnosed as smallpox, and the patient was discharged from hospital after 25 days.

The case histories summarized above are typical of many cases occuring in the United States. One relates to a patient repeatedly vaccinated, with negative results; another to a patient recently successfully vaccinated; the third to a patient who had never been vaccinated; and the fourth to a patient concerning whom there was no record of vaccination status. The first case shows both smallpox and chicken-pox, the disease which is most commonly confused with mild smallpox. In the second case, the question might arise as to whether the case was one of a generalized vaccinia. The belief held by many observers is that generalized vaccinia is a rare disease. The fact that many cases came into camp with active lesions of smallpox and others gave

a

history of contact while at home and arrived in camp within the incubation period, throws the weight of evidence in favor of a diagnosis of mild smallpox rather than vaccinia. This was the consensus of opinion among medical officers stationed in the larger hospitals. The mild character of the disease is evidenced by the fact that 22 per cent of the cases were diagnosed varioloid.

DIAGNOSIS

The diagnosis of smallpox is neither simple nor certain prior to the appearance of the eruption. Even then it may offer considerable difficulty if the number of lesions is small. In mild cases, occurring sporadically, the difficulty is increased. This was the experience of the Army during the World War. With universal vaccination in effect, the cases generally were mild, as is shown by the very low case-fatality rate. In but few instances, for example, at Dijon, was it possible to trace the source of infection to persons in the military service, and it but seldom was feasible personally to verify histories of exposure to civilian contacts. The general symptom-complex of a more or less sudden onset, generalized pains, headache, backache, chills, fever, nausea, and vomiting, is not peculiar to smallpox. Most of the eruptive diseases, as well as influenza, present such signs and symptoms in varying degrees of intensity. It was a matter of differential diagnosis and each stage, from the prodromal to the well-marked pustular or scab stage, offered new difficulties. During the prodromal stage the following symptoms were most common, and in the order named: Headache, backache, pains in bones and joints, fever, chills, nausea and vomiting, vertigo, and chest pains. This syndrome necessitated consideration of a diagnosis of influenza, meningitis, and the pneumonias. The differential diagnosis between smallpox and influenza was difficult and sometimes impossible until appearance of the eruption. If no eruption was present by the fourth day, a diagnosis of influenza was considered safe. There were 30 cases in which a tentative diagnosis of influenza was later changed to smallpox. In several instances the resemblance to meningitis led to lumbar puncture. Pneumonia and bronchitis were not uncommon complications, especially among severe cases; pneumonia was reported in five of the more severe cases. These cases were admitted to hospital as pneumonia and the diagnosis of smallpox subsequently was made. In such instances there is a question whether the pneumonia was a complication or whether smallpox was merely a concurrent disease. The clinical records of World War cases do not indicate that typhus or the ty phoid fevers caused any particular concern in differentiation from smallpox, though several cases were under observation for typhoid fever over a period of several days before the final diagnosis of smallpox was made.

Since the prodromal rash may be either morbilliform or scarlatinaform, measles, German measles, and scarlet fever were of necessity given consideration. There were 6 admissions to hospital with an original diagnosis of measles, 1 of German measles, and 5 of scarlet fever in which the diagnosis was changed to smallpox after further observation.

Measles was of very common occurrence, and it is not surprising that some confusion was encountered in differentiating it from smallpox. There were 5 cases of smallpox in which measles was diagnosed as a concurrent disease and 6

of measles where an additional diagnosis of smallpox was made. There were 8 cases, with 1 death, in which scarlet fever was a concurrent disease. The case in which death resulted was one of hemorrhagic smallpox contracted in Siberia. It ended fatally after eight days in hospital.

The angina commonly seen in smallpox occasionally led to the consideration of diphtheria. As a concurrent disease, diphtheria was recorded in one case, and, in addition, the clinical records not uncommonly showed the results of repeated cultural and bacteriological examinations for the Klebs-Loeffler baccilus. Drug rash occasionally presented difficulty in diagnosis. This was especially true for iodide and copaiba rashes. The former drug is in common use in the Army and the records show one case sent to hospital as "drug rash" (iodide) in which the final diagnosis was smallpox.

During the vesicular and pustular stages differential diagnosis ordinarily offers no great difficulty to persons conversant with smallpox when the rash is typical. But few medical officers in the Army were clinically conversant with smallpox in atypical form as noted during the World War and there was difficulty in diagnosis.

The clinical records show that cases of smallpox in the United States usually were afebrile unless accompanied by some condition other than smallpox that could account for the elevation of temperature. During the vesicular and pustular stages, syphilis and chicken-pox caused the greatest concern in differential diagnosis. The former was common in the Army. Where discrete lesions occurred, irrespective of type, especially when of recent onset and accompanied by fever, there was a tendency to make a presumptive diagnosis of syphilis. The clinical records indicate that not infrequently consultants from the venereal services were called in before a final diagnosis of smallpox was made. The Wassermann test, consultation, study of vaccination status, general signs and symptoms, especially of the skin and mouth, with observation, were the methods used in arriving at a diagnosis. Even after the use of all available methods in large base hospitals, several cases were sent to duty and recorded as smallpox in which doubt is expressed in the records as to the true diagnosis.

It was with chicken-pox, especially, that difficulty was encountered in differential diagnosis. An analysis of 100 clinical records of smallpox cases shows that 47 per cent were admitted to hospital during the vesicular or pustular stage, and that 9 per cent were thought to be chicken-pox. There were two cases of chicken-pox in which smallpox was diagnosed as a concurrent disease and three cases of smallpox in which chicken-pox was recorded as an additional disease. One case was discharged from hospital after 23 days in isolation, during which time both diagnoses had been considered and no decision was reached as to what the real diagnosis was.

COMPLICATIONS AND SEQUELÆ

The complications and sequelæ of smallpox are usually due to secondary pyogenic infection, and are dependent on the severity of the skin lesions. As the type of disease occurring in military personnel was mild, except in Siberia and in the Philippines, it is not surprising that the complications and sequelæ were also mild in character.

Among the diseases recorded as secondary or concurrent diseases were: Erysipelas, carbuncle, furunculosis, abscesses, and impetigo. There were four cases of erysipelas and two of impetigo. One case with multiple abscesses and one with impetigo ended fatally. Eye and ear complications were uncommon.

The most important complications were those of the respiratory tract, which included 12 cases of bronchitis with recovery, 2 of bronchopneumonia with 1 death, and 4 of lobar pneumonia with 1 death.

Of the 780 primary admissions in the United States, only 1 ended fatally, and that case was complicated with scarlet fever.

Among the total primary admissions, 126 complications and associated diseases were recorded, with 8 deaths. The remaining deaths, 6 in number, show no other diagnosis than smallpox or toxemia. There were no cases of tetanus following vaccination or associated with smallpox.

REFERENCES

(1) Spalding, Heman: Smallpox (Variola) and its Prevention. The Chicago Medical Recorder, Chicago, 1917, xxxix, No. 11, 490.

(2) Macaulay, History of England, Vol. IV, 53.

(3) Rosenau, M. J.: Preventive Medicine and Hygiene. D. Appleton & Co., New York and London, 1927, fifth edition, 28.

(4) Annual report of the Surgeon General, U. S. Army, 1899, 250.

(5) Handbuch der Ärztlichen Erfahrungen im Weltkriege, Band iii, Innere Medizin, Leipzig, Johann Ambrosius Barth, 1921, 265.

(6) Osler, Sir William: The Principles and Practice of Medicine. D. Appleton & Co., New York and London, 1914, eighth edition, 315.

(7) Medical and Surgical History of the War of the Rebellion, Part third, Volume I, Medical History, Washington, Government Printing Office, 1888, 625.

(8) Annual Report of the Surgeon General, U. S. Army, 1899, 207.

(9) Heiser, V. C., and Leach, C. N.: Vaccination in the Philippines Still Effective. Journal of the American Medical Association, Chicago, 1922, lxxix, No. 1, 40.

(10) Philippine Islands, Health Service Annual Reports, 1918, 1919.

(11) History of Medical Department activities, Camp Bowie, Tex., prepared under the direction of the camp surgeon. On file, Historical Division, S. G. O.

(12) History of Medical Department activities, Camp Devens, Mass., prepared under the direction of the camp surgeon. On file, Historical Division, S. G. O.

(13) History of Medical Department activities, Camp Dodge, Iowa, prepared under the direction of the camp surgeon. On file, Historical Division, S. G. O.

(14) History of Medical Department activities, Camp Funston, Kans., prepared under the direction of the camp surgeon. On file, Historical Division, S. G. O.

(15) History of Medical Department activities, Camp Pike, Ark., prepared under the direction of the camp surgeon. On file, Historical Division, S. G. O. (16) History of Medical Department activities, Camp Taylor, Ky., prepared under the direction of the camp surgeon. On file, Historical Division, S. G. O. (17) Leake, J. P., and Force, J. N.: The Essentials of Smallpox Vaccination. Smallpox in Twenty States, 1915-1920. Weekly Public Health Reports, U. S. Public Health Service, Government Printing Office, Washington, August 19, 1921, xxxvi, Part 2, No. 33, 1975, 1979.

(18) Public Health Reports, U. S. Public Health Service, Government Printing Office (The Notifiable Diseases, Prevalence in States in 1917, 1918, 1919). Reprints Nos. 505, February, 1919, 551, August, 1919, and 643, February, 1921.

(19) Letter from the director of laboratories, A. E. F., to the commanding officer of troops stationed at Dijon, February 5, 1919. Subject: Smallpox. Copy on file, A. G. O., World War Division, chief surgeon's files, 710-Smallpox.

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