**3. Microbiology**

Neonatal osteomyelitis arises as a consequence of hematogenous spread of microorganisms, which is the most common route of infection. In preterm infants, neonatal osteomyelitis

© 2013 Kiechl-Kohlendorfer and Griesmaier, licensee InTech. This is an open access chapter distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. © 2013 Kiechl-Kohlendorfer and Griesmaier, licensee InTech. This is a paper distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

frequently results from directly inoculated bacteria (secondary to heel or venipuncture, umbilical catheterization, infected cephalhematoma, etc.) [14,15]. Premature rupture of membranes and transplacental infection have also been described as risk factors for neonatal osteomyelitis [16].

Neonatal Osteomyelitis 35

local swelling, and 2) a severe form, with the predominant manifestation of a sepsis-like syndrome with multiple bone sites being noted as manifestations [28]. In neonates, almost

**Figure 1.** Anatomic depiction of blood supply to the epiphysis and metaphysis in the developing bone that influences the progression of osteomyelitis in the neonate (modified and redrawn from Kaye JJ et

Clinical symptoms and signs of osteomyelitis in the neonate are at first frequently unspecific and mild. They may include temperature instability, feeding intolerance, irritability or reduced movement, frequently giving rise to the suspicion of secondary sepsis. Fever is a rare condition that could be explained by a rather poorly developed immune system. As the disease progresses, more specific signs may become present, including disability, local swelling or erythema. Focal tenderness over a long bone should catch the physician's attention. In some cases subcutaneous abscess formation prompts the diagnosis of

In general, there is no specific laboratory test for osteomyelitis. Neonates with osteomyelitis frequently show normal leukocyte counts and erythrocyte sedimentation rates in the first

osteomyelitis. Hip, knee and shoulder are most frequently involved [7,28,29].

half of all cases involve two or more bones.

al, [53]).

**5.2. Laboratory findings** 

The most common bacterial pathogen causing osteomyelitis in children is *Staphylococcus aureus* in all age groups [17]. Group B streptococcus (Streptococcus agalactiae) and gramnegative organisms (E. coli and Klebsiella pneumonia) are also important bacteria in the neonatal period [16,18,19]. Community-acquired strains of methicillin-resistant *Staphylococcus aureus* have emerged as being relevant in recent years and cause serious infections in the neonate [12,20,21].
