CLINICAL OBSERVATIONS AND TREATMENT riod of granulocytopenia was indicative of some granuloeyte regeneration. White counts were repeated at 3 to + day intervals on all of the exposed individuals and more frequently on those with the lowest counts. Individuals with symptoms or elevated temperatures were treated only after an attempt to establish a diagnosis was made, even if a period of observation was necessary. During the observation period. the patients were examined at frequent intervals and the temperatures checked every few hours. Twenty-seven individuals had total leukocyte counts of 4000 or below or absolute neutrophile counts of 2500 or less at some time during the period of observation. Of these 27, 13 developed symptoms of disease that required evaluation for possible antibiotic therapy. The 13 instances in which it was necessary to consider the use of antibiotic therapy in neutropenic individuals are summarized below: Eight neutropenic individuals had symtoms of upper respiratory infection (URI) characterized by malaise, sore throat, nasal discharge. and temperatures between 99 and 101.4° F. The temperatures returned to normal within 24 hours. Since the response of this group to URI appeared identical with that of other individuals with URI without neutropenia, no special therapy was given. Two individuals developed symptoms of marked malaise, headache, abdominal pain, nausea and diarrhea. Both were children, one age 7, the other age 2. In both instances, the symptoms were out of proportion to the physi‘al findings, which were negative except for evidence of head colds and pharyngeal injection. The 7-vearold child hadan oral temperature of 102.6° F. whenfirst seen and + hours later. it was 104° F. The two-year old child had an initial axillary temperature of 101.8° F. whichrose to 103.5° F. in t hours. Both were given 300,000 units of procaine penicillin intramuscularly whenthe sharp rise in temperature oceurred, and both were afebrile the following day. secondinjection of penicillin was given at this time, and therapy was discontinued. In spite of the fact that the neutrophiles remained 17 depressed in both cases long after the fever had passed, both individuals recovered and had no further illness. In Figure 2.1 the leukocyte and platelet counts of the 2-year old patient and the time of the occurrence of the febrile illness are illustrated. A one-year-old boy had had symptoms of mild upper respiratory infection for several days and was brought to the clinic when he developed a hacking cough. When he was seen, his axillary temperature was 100.8° F. He had signs of URI, there was pharyngeal injection, and numerous coarse rhonchi were heard throughout the chest. .A diagnosis of upper respiratory infection with associated bronchitis was made and the child was given a single intramuscular injection of 200,000 units procaine penicillin, On the following dayhis temperature was 99° F., no rales or rhonchi were heard, and he recovered without further treatment. A. 50-year-old man came to the clinic complaining of weakness, nervousness, mild abdominal pain and shooting pain in the upper anterior chest bilaterally of several hours duration. He appeared moderatelyill, his temperature was 99.6° F., and the only positive physical finding was moderate tenderness in the right upper quadrant of the abdomen. Within a 10-hour period the temperature rose to 101.6° F., following which it fell gradually to normal. The abdominal tenderness continued for 24 hours and then gradually disappeared during the subsequent 2 days. A tentative diagnosis of cholecystitis was made. No specific therapy was given. In Figure 2.2 his white blood cell and platelet counts in relation to the appearance of symptomsare shown. A female, age 38, developed generalized urticaria, fever, and headache. No cause for the urticaria was found and the symptomssubsided within 8 hours without any therapy. All individuals in Groups I and IT that received antibiotics are listed in Table 2.1. Of the individuals treated with antibiotics, only the first three received it at a time whentheir neutrophile count was low. These cases are