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Relationship of Fever Magnitude to Rate of Serious Bacterial infections in Infants Aged 4-8 Weeks William A. Bonadio, Kimberly McElroy, Patricia L. Jacoby and Douglas Smith CLIN PEDIATR 1991 30: 478 DOI: 10.1177/000992289103000803 The online version of this article can be found at: http://cpj.sagepub.com/content/30/8/478
Published by: http://www.sagepublications.com
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Relationship of Fever Magnitude to
Rate of
Serious Bacterial infections in Infants Aged 4-8 Weeks William A. Bonadio, MD;
Kimberly McElroy, MD; Patricia L. Jacoby; Douglas Smith, MD
We correlated the height of fever with underlying infectious etiology in 683 consecutive febrile infants aged four to eight weeks who received outpatient evaluation for sepsis during a five-year period. The relative number of infants with fever was inversely proportional to fever height, as 51 % had a temperature 38.1 - 38.9°C, 45% had a temperature 39 - 39.9°C, and 4% had a temperature >40°C [hyperpyrexia]. There were 34 cases of serious bacterial infections [SBI], including 16 cases of urinary tract infection, 8 cases of bacteremia, 6 cases of bacterial meningitis, and 4 cases of Salmonella enteritis. The rate of SBI increased in direct proportion to fever height, being 3.2% in those with a temperature 38.1-38.9°C, 5.2% in those with a temperature 39-39.9°C, and 26% in those with a temperature >40°C. The 6.8% rate of SBI in those with fever >39°C was significantly greater and the 26% rate of SBI in those with than the 3.2% rate in those with fever 100,000 colony forming units per milliliter. Chi-square test was performed to determine the signifiof the difference in rates of SBI between 1) those with fever 40°C were calculated. cance
Table 1. Fever 4 to 8 weeks
magnitude
correlated with outcome in infants agec
of fever in those aged 2 to 24 months, with maximal risk occurring when fever exceeds 40’C.1-l’ A recent study’ of febrile infants aged zero to four weeks showed that the rate of SBI was directly proportional to fever height, and was significantly greater in those with hyperpyrexia compared to those with lesser degrees of fever. By contrast, a recent abstract6 reporting on the results of a large series of febrile infants aged four to eight weeks found that the height of
Results There were 683 infants who met the criteria for study. Table 1 shows the distribution of body temperatures of all infants [none had a temperature >41 °C], and correlates the diagnoses of the 34 cases of SBI with the height of fever. The discharge diagnoses of the 649 culture-negative infants included 250 with nonspecific febrile illness, 159 with upper respiratory tract infection, 82 with gastroenteritis, 81 with bronchiolitis, 47 with aseptic meningitis [6 with a temperature >40°C], 20 with pneumonia [none had a positive blood culture], and 10 with otitis media. Table 2 gives the results of statistical analysis, and shows there was a significantly greater rate of SBI with higher degrees of fever. For outcome of SBI, the presence of temperature >_40°C had a sensitivity of 21 %, specificity of 97%, positive-predictive value of 25 %, and negative-predictive value of 96%.
Discussion Numerous studies have examined the
relationship
be-
tween fever height and SBI rate in children. The rate of SBII
has been shown to correlate directly with increasing degree
Table 2. Statistical Analysis
fever did not significantly correlate with the rate of underlying SBI. Although febrile infants younger than eight weeks old are commonly grouped together as a single entity, those aged four to eight weeks constitute a distinct subgroup relative to younger infants by virtue of their lower rates of SBI, bacterial meningitis, and isolated bacteremia. 11 The present is the only completed study to our knowledge which specifically correlates height of fever with SBI rate 479
Downloaded from cpj.sagepub.com at UNIV OF NEVADA RENO on August 23, 2014
in infants aged four to eight weeks. We found an overall rate of SBI in these infants of 5%, which is less than the 9.5% rate previously observed in a series of febrile infants aged four to eight weeks old,&dquo; and is also less than 6.3 to 11.4% range of rates documented in febrile infants zero to eight weeks old in other series.2-5 Similar to fever patterns previously noted in febrile infants younger than four weeks old the present study found no cases in which the temperature was > 41.0°C. The relative percentage of infants
aged four to eight weeks with fever was inversely proportional to fever height. Conversely, the rate of SBI increased in direct proportion to fever magnitude, and was significantly greater in both those with fever >39°C and with hyperpyrexia relative to the respective groups having lesser degrees of fever. The rarity of hyperpyrexia in young infants has been previously observed. During a seven-yearperiod, McCarthy and Dolan’3 observed only nine cases of hyperpyrexia in infants younger than eight weeks old. Others have shown that hyperpyrexia is relatively uncommon compared to lower degrees of fever in infants younger than 8 weeks old, occurring in approximately 2% of cases. 2,14 In our series, 4% of all febrile infants aged four to eight weeks had hyperpyrexia, which is similar to the 6% rate of hyperpyrexia observed in febrile infants aged zero to four weeks.’ Although uncommon, hyperpyrexia was commonly associated with underlying serious infection, as 26% had SBI, and 48% had either SBI or aseptic meningitis. Yet the presence of hyperpyrexia per se was not accurate in predicting the individual infant with SBI, as only about one-fourth of all such cases of SBI were associated with this degree of fever.
References Fever in the first eight weeks of life. Johns 141:9-13. Crain EF, Shelov SP. Febrile infants: predictors of bacteremia. J Pediatr 1982; 101:686-9. Caspe WB, Chamudes O, Louie B. The evaluation and treatment of the febrile infant. Pediatr Infect Dis J 1983; 2:131-5. Dagan R, Powell KR, Hall CB, et al. Identification of infants unlikely to have serious bacterial infection although hospitalized for suspected sepsis. J Pediatr 1985; 107:955-60. King JC, Berman ED, Wright PF. Evaluation of fever in infants less than eight weeks old. South Med J 1987; 80:948-52. Avner JR, Baker MD, Bell LM. Predictors of bacterial illness in febrile four to eight week old infants. AJDC 1990; 144:422. Bonadio WA, Romine K, Gyuro J. Relationship of fever magnitude to rate of serious bacterial infection in neonates. J Pediatr 1990; 116:735-7. McCarthy PL, Grundy GW, Spiesel SZ, et al. Bacteremia in children: an outpatient clinical review. Pediatr 1976; 57:861-8. McGowan JE, Bratton L, Klein JO, et al. Bacteremia in febrile children seen in a "walk-in" pediatric clinic. N Engl J Med 1973; 288:1309-12. Teele DW, Pelton SI, Grant MJ, et al. Bacteremia in febrile children under two years of age: results of cultures of blood of 600 consecutive febrile children seen in a "walk-in" clinic. J Pediatr 1975; 87:227-30. Bonadio WA. Evaluation and management of serious bacterial infections in the febrile young infant. Pediatr Infect Dis J 1990; 9:905-12. Baker M, Avner JR, Bell LM. Failure of infant observation scales in detecting serious illness in febrile, four to eight week old infants. Pediatr 1990; 85:1040-3. McCarthy PL, Dolan TF. The serious implications of high fever in infants during their first three months. Clin Pediatr 1976; 15:794-7. Rosenberg N, Vranesich P, Cohen S. Incidence of serious infection in infants under two months with fever. Pediatr Emerg Care 1985; 1:54-6.
1. Roberts KB,
Borzy MS.
Hopkins MedJ 1977;
2. 3. 4.
5.
6. 7.
8.
9.
10.
11.
12.
13. 14.
480
Downloaded from cpj.sagepub.com at UNIV OF NEVADA RENO on August 23, 2014
Relationship of Fever Magnitude to Rate of Serious Bacterial infections in Infants Aged 4-8 Weeks William A. Bonadio, Kimberly McElroy, Patricia L. Jacoby and Douglas Smith CLIN PEDIATR 1991 30: 478 DOI: 10.1177/000992289103000803 The online version of this article can be found at: http://cpj.sagepub.com/content/30/8/478
Published by: http://www.sagepublications.com
Additional services and information for Clinical Pediatrics can be found at: Email Alerts: http://cpj.sagepub.com/cgi/alerts Subscriptions: http://cpj.sagepub.com/subscriptions Reprints: http://www.sagepub.com/journalsReprints.nav Permissions: http://www.sagepub.com/journalsPermissions.nav Citations: http://cpj.sagepub.com/content/30/8/478.refs.html
>> Version of Record - Aug 1, 1991 What is This?
Downloaded from cpj.sagepub.com at UNIV OF NEVADA RENO on August 23, 2014
Relationship of Fever Magnitude to
Rate of
Serious Bacterial infections in Infants Aged 4-8 Weeks William A. Bonadio, MD;
Kimberly McElroy, MD; Patricia L. Jacoby; Douglas Smith, MD
We correlated the height of fever with underlying infectious etiology in 683 consecutive febrile infants aged four to eight weeks who received outpatient evaluation for sepsis during a five-year period. The relative number of infants with fever was inversely proportional to fever height, as 51 % had a temperature 38.1 - 38.9°C, 45% had a temperature 39 - 39.9°C, and 4% had a temperature >40°C [hyperpyrexia]. There were 34 cases of serious bacterial infections [SBI], including 16 cases of urinary tract infection, 8 cases of bacteremia, 6 cases of bacterial meningitis, and 4 cases of Salmonella enteritis. The rate of SBI increased in direct proportion to fever height, being 3.2% in those with a temperature 38.1-38.9°C, 5.2% in those with a temperature 39-39.9°C, and 26% in those with a temperature >40°C. The 6.8% rate of SBI in those with fever >39°C was significantly greater and the 26% rate of SBI in those with than the 3.2% rate in those with fever 100,000 colony forming units per milliliter. Chi-square test was performed to determine the signifiof the difference in rates of SBI between 1) those with fever 40°C were calculated. cance
Table 1. Fever 4 to 8 weeks
magnitude
correlated with outcome in infants agec
of fever in those aged 2 to 24 months, with maximal risk occurring when fever exceeds 40’C.1-l’ A recent study’ of febrile infants aged zero to four weeks showed that the rate of SBI was directly proportional to fever height, and was significantly greater in those with hyperpyrexia compared to those with lesser degrees of fever. By contrast, a recent abstract6 reporting on the results of a large series of febrile infants aged four to eight weeks found that the height of
Results There were 683 infants who met the criteria for study. Table 1 shows the distribution of body temperatures of all infants [none had a temperature >41 °C], and correlates the diagnoses of the 34 cases of SBI with the height of fever. The discharge diagnoses of the 649 culture-negative infants included 250 with nonspecific febrile illness, 159 with upper respiratory tract infection, 82 with gastroenteritis, 81 with bronchiolitis, 47 with aseptic meningitis [6 with a temperature >40°C], 20 with pneumonia [none had a positive blood culture], and 10 with otitis media. Table 2 gives the results of statistical analysis, and shows there was a significantly greater rate of SBI with higher degrees of fever. For outcome of SBI, the presence of temperature >_40°C had a sensitivity of 21 %, specificity of 97%, positive-predictive value of 25 %, and negative-predictive value of 96%.
Discussion Numerous studies have examined the
relationship
be-
tween fever height and SBI rate in children. The rate of SBII
has been shown to correlate directly with increasing degree
Table 2. Statistical Analysis
fever did not significantly correlate with the rate of underlying SBI. Although febrile infants younger than eight weeks old are commonly grouped together as a single entity, those aged four to eight weeks constitute a distinct subgroup relative to younger infants by virtue of their lower rates of SBI, bacterial meningitis, and isolated bacteremia. 11 The present is the only completed study to our knowledge which specifically correlates height of fever with SBI rate 479
Downloaded from cpj.sagepub.com at UNIV OF NEVADA RENO on August 23, 2014
in infants aged four to eight weeks. We found an overall rate of SBI in these infants of 5%, which is less than the 9.5% rate previously observed in a series of febrile infants aged four to eight weeks old,&dquo; and is also less than 6.3 to 11.4% range of rates documented in febrile infants zero to eight weeks old in other series.2-5 Similar to fever patterns previously noted in febrile infants younger than four weeks old the present study found no cases in which the temperature was > 41.0°C. The relative percentage of infants
aged four to eight weeks with fever was inversely proportional to fever height. Conversely, the rate of SBI increased in direct proportion to fever magnitude, and was significantly greater in both those with fever >39°C and with hyperpyrexia relative to the respective groups having lesser degrees of fever. The rarity of hyperpyrexia in young infants has been previously observed. During a seven-yearperiod, McCarthy and Dolan’3 observed only nine cases of hyperpyrexia in infants younger than eight weeks old. Others have shown that hyperpyrexia is relatively uncommon compared to lower degrees of fever in infants younger than 8 weeks old, occurring in approximately 2% of cases. 2,14 In our series, 4% of all febrile infants aged four to eight weeks had hyperpyrexia, which is similar to the 6% rate of hyperpyrexia observed in febrile infants aged zero to four weeks.’ Although uncommon, hyperpyrexia was commonly associated with underlying serious infection, as 26% had SBI, and 48% had either SBI or aseptic meningitis. Yet the presence of hyperpyrexia per se was not accurate in predicting the individual infant with SBI, as only about one-fourth of all such cases of SBI were associated with this degree of fever.
References Fever in the first eight weeks of life. Johns 141:9-13. Crain EF, Shelov SP. Febrile infants: predictors of bacteremia. J Pediatr 1982; 101:686-9. Caspe WB, Chamudes O, Louie B. The evaluation and treatment of the febrile infant. Pediatr Infect Dis J 1983; 2:131-5. Dagan R, Powell KR, Hall CB, et al. Identification of infants unlikely to have serious bacterial infection although hospitalized for suspected sepsis. J Pediatr 1985; 107:955-60. King JC, Berman ED, Wright PF. Evaluation of fever in infants less than eight weeks old. South Med J 1987; 80:948-52. Avner JR, Baker MD, Bell LM. Predictors of bacterial illness in febrile four to eight week old infants. AJDC 1990; 144:422. Bonadio WA, Romine K, Gyuro J. Relationship of fever magnitude to rate of serious bacterial infection in neonates. J Pediatr 1990; 116:735-7. McCarthy PL, Grundy GW, Spiesel SZ, et al. Bacteremia in children: an outpatient clinical review. Pediatr 1976; 57:861-8. McGowan JE, Bratton L, Klein JO, et al. Bacteremia in febrile children seen in a "walk-in" pediatric clinic. N Engl J Med 1973; 288:1309-12. Teele DW, Pelton SI, Grant MJ, et al. Bacteremia in febrile children under two years of age: results of cultures of blood of 600 consecutive febrile children seen in a "walk-in" clinic. J Pediatr 1975; 87:227-30. Bonadio WA. Evaluation and management of serious bacterial infections in the febrile young infant. Pediatr Infect Dis J 1990; 9:905-12. Baker M, Avner JR, Bell LM. Failure of infant observation scales in detecting serious illness in febrile, four to eight week old infants. Pediatr 1990; 85:1040-3. McCarthy PL, Dolan TF. The serious implications of high fever in infants during their first three months. Clin Pediatr 1976; 15:794-7. Rosenberg N, Vranesich P, Cohen S. Incidence of serious infection in infants under two months with fever. Pediatr Emerg Care 1985; 1:54-6.
1. Roberts KB,
Borzy MS.
Hopkins MedJ 1977;
2. 3. 4.
5.
6. 7.
8.
9.
10.
11.
12.
13. 14.
480
Downloaded from cpj.sagepub.com at UNIV OF NEVADA RENO on August 23, 2014
