A Rare Duo: Bacterial Parotitis and CMV in a Neonate—Case Report and Diagnostic Challenges

Background Neonatal salivary gland infections still stand as a significant challenge for clinicians in both diagnosis and management due to their rarity and potential complications. Key risk factors include dehydration, prematurity, and immunodeficiency, which contribute to secretory stasis and bacterial superinfection. While bacterial parotitis, typically caused by Staphylococcus aureus or Streptococcus species, is well-documented, the role of viral co-infections such as cytomegalovirus (CMV) remains unclear. Case Presentation A 7-day-old full-term, breastfed girl was admitted with right preauricular swelling and reduced oral intake. She was born without complications, and she exhibited irritability and purulent discharge from the right Stensen’s duct. Laboratory tests revealed neutrophilic leukocytosis, while ultrasonography confirmed an enlarged right parotid gland with abscess formation. Initial treatment with clindamycin and cefotaxime was adjusted to clindamycin monotherapy and oral cefaclor after S. aureus was found in the ductal exudate and maternal breast milk. Prompted by neurological symptoms, a cerebral ultrasonography revealed cystic changes and vascular abnormalities. Despite documented maternal immunity, CMV was detected in both urine and salivary specimens. The patient demonstrated full recovery from antimicrobial therapy, with resolution of swelling and normalization of feeding, and was discharged after 10 days with CMV-related follow-up. Conclusions In neonates presenting with acute parotitis, particularly with neurological signs, CMV should be considered due to its multiorgan involvement and link to immunodeficiency. Ultrasound is pivotal in both the diagnosis and management of parotitis and screening for any neurological involvement when neurological symptoms are present. Comprehensive imaging and laboratory evaluation are crucial for early detection, therapeutic guidance, and prevention of long-term sequelae.