Does a child with a fever without a visible source of infection have a greater risk of developing hidden bacteremia than a child with a clear focus of infection? The answer depends on the type of focal infection we choose for comparison. For such serious diseases as bacterial meningitis or epiglottitis, the frequency of bacteremia is close to 100%. However, the question asked is more related to outpatients who may be at home due to their condition.
It is more appropriate to compare patients with fever without local symptoms and patients suffering from infectious diseases that are usually treated at home. According to McCarthy, in patients with fever without obvious foci of infection, the frequency of bacteremia was 9.9% compared with 5.9% in all other patients who had blood cultures. However, the last group included patients with meningitis, epiglottitis and septic arthritis.
In patients with common outpatient diseases such as otitis media, pneumonia, upper respiratory tract infection and flu-like diseases, bacteremia was diagnosed in 3.3% of cases, which amounted to 7,3 of the frequency of bacteremia in children without focal symptoms.
In a prospective study conducted by Teele et al., Blood cultures were conducted in all children with fever observed in the clinic. At the same time, bacteremia was detected in 3.9% of patients with a body temperature of 39 ° C and higher in the absence of focal symptoms or in the presence of only an infection of the upper respiratory tract.
As mentioned earlier, this figure would be higher if the author limited his study to children with fever without local symptoms and did not include patients with upper respiratory tract infection.
For example, in similar work, the incidence of bacteremia in children with pharyngitis and otitis media and with the same temperature was only 1.5%. According to Baron, the frequency of bacteremia in deguies between the ages of 3 and 24 months has reached; 5.5%.
Thus, in patients with unexplained fever, the frequency of bacteremia ranges between 4 and 10%, since. 2–3 times more than in children with respiratory diseases or soft tissue infections.