The Surgical Infection Society (SIS) Guidelines on the Prevention and Management of Pediatric Intra-Abdominal Infection Update was just published.¹ These authors note that these are to be used in conjunction with the prior guidelines, as many aspects have not changed. Source control remains essential. For treatment they continue to recommend the combination of ceftriaxone (or cefotaxime, if available) with metronidazole or monotherapy with ertapenem for lower-risk infants, children, and adolescents. After achievement of source control, antibiotic duration in patients beyond the neonatal period (i.e., > 45 weeks post conceptional age), should be limited to 5 days.¹ In cases of perforated appendicitis complicated by post-operative abscess, the guideline recommends antibiotic duration should not exceed 7 days. Therapy should be transitioned to oral agents with high bioavailability as early as feasible.  The guidelines also discuss risk categories, although their definition includes some elements that are adult focused (e.g., advanced age), most of the high-risk features (e.g., septic shock, delayed or inadequate source control, post-operative intra-abdominal infections, multiple medical comorbidities or cancer, those with a history of a multi-drug resistant organism) are directly applicable to the pediatric population.¹

What is currently recommended for treatment of intra-abdominal infections per SIS?

How should we treat infants?

The guidelines made specific recommendations for the treatment of two groups of infants. The first was preterm infants.¹ This is based on findings of no differences reported in clinical outcomes from an open label, multicenter trial that included infants (n=180) that were ≤ 33 weeks gestational age and <121 days old.^1,2 The antibiotic regimens included in the study and recommended for preterm infants with intra-abdominal infection (primarily necrotizing enterocolitis) are: ampicillin and gentamicin with either metronidazole or clindamycin or piperacillin-tazobactam with gentamicin.^1,2  Although the first 2 regimens are standard, the rational for the study combining gentamicin with the piperacillin-tazobactam, resulting in dual Gram-negative coverage, is not entirely clear.  The second infant recommendation is that metronidazole is the anti-anaerobic agent of choice for combination therapy in infants.¹ This recommendation was based on a multicenter open label trial that included infants of ≥34 weeks gestational age and < 121 days old.^1,3 All patients received metronidazole as part of their intra-abdominal infection treatment. The panel cited high overall cure rates (98%) along with low rates of death (2%), intestinal perforation (2%), and intestinal stricture (2%).^1,3

What about empiric treatment of older infants, children and adolescents

For empiric therapy of intra-abdominal infection in older pediatric patients.¹ The guidelines recommend having antimicrobial stewardship protocols in place to help improve appropriateness of antibiotic choice. Data further suggest that enterococcal specific targeted therapy is not needed.

For empiric choices of antibiotics in those with low-risk disease, they recommend ceftriaxone (or cefotaxime, where available) both in combination with metronidazole or monotherapy with ertapenem.¹ In patients who meet high-risk criteria the guidelines did add the broad-spectrum cephalosporin-beta-lactamase combinations: ceftolozane/tazobactam and ceftazidime-avibactam based on small outcome studies used to obtain pediatric FDA approval for intra-abdominal infections.^1,4,5 Note that the guidelines suggest, and antimicrobial stewardship principles strongly recommend protecting and reserving these agents when the patient is at high risk, such as those with known resistance to usual agents.¹

Antimicrobial therapy the SIS guidelines recommend against moxifloxacin for empiric therapy.^1,6  This recommendation authors note was due to a combination of increased rate of antibiotic attributed adverse effects (14% vs 7%) and lower cure rates (85% vs 96%).^1,6

What are the recommendations for perforated appendicitis?

Different antibiotics (i.e., piperacillin-tazobactam or ertapenem) are recommended by the SIS for perforated appendicitis.¹  The panel did not endorse the use of ceftriaxone and metronidazole for perforated appendicitis, comparing the 2 in pediatrics. The IMPACT study found that piperacillin-tazobactam had significantly lower rates of post-operative intra-abdominal abscesses (6% vs 24%), need for post-op CT scanning (14% vs 30%), emergency department visits (9% vs 26%).^1,7 Further, authors reported the choice of medication was most significant predictor of the intra-abdominal post-operative abscess formation.^1,7 However, the evidence is not entirely one-sided. A 2025 meta-analysis published after the SIS pulled their study data, incorporating the IMPPACT trial and 3 retrospective studies did not find significant differences between antibiotic regimens. Because 3 of the 4 studies were observational, there is some concern for selection bias.⁸  As such, the question may still be up for debate.

The randomized study supporting ertapenem’s inclusion, compared it versus gentamicin and metronidazole, a regimen not commonly used for pediatric perforated appendicitis in the US.^1,9 While patients who received the ertapenem became afebrile 2 days sooner, no differences were reported for other clinical outcomes.^1,9 This study is important, but also raises some generalizability questions about how it compares to currently used regimens.

That said, the evidence in this area remains nuanced.  It will be interesting to see how the upcoming Infectious Diseases Society of America intra-abdominal infection guidelines update addresses these same questions.

When can therapy be transitioned to PO?

Data support transitioning from intravenous to oral therapy once source control is achieved in pediatric patients with perforated disease.¹ In the pediatric studies supporting this recommendation, commonly used oral antibiotics included amoxicillin/clavulanate monotherapy or trimethoprim/sulfamethoxazole with metronidazole.¹

Key Stewardship Takeaways

This update to the SIS recommendations for pediatric patients with intra-abdominal infections summarizes the current literature and highlights the importance of antimicrobial stewardship including having established protocols, choice of antimicrobial therapy, and evidence-based transition to oral therapy for pre-determined durations.  Although there are nuanced considerations, overall, it provides guidance to help support improved patient care in this area.

References

1. Huston JM, Forrester JD, Barie PS, et al. Surgical Infection Society Guidelines on the Prevention and Management of Pediatric Intra-Abdominal Infection: 2025 Update. Surg Infect (Larchmt). 2026;27(1):5–15.
2. Smith MJ, Boutzoukas A, Autmizguine J, et al. Antibiotic Safety and Effectiveness in Premature Infants With Complicated Intraabdominal Infections. Pediatr Infect Dis J. 2021;40(6):550–555.
3. Commander SJ, Gao J, Zinkhan EK, et al. Safety of Metronidazole in Late Pre-term and Term Infants with Complicated Intra-abdominal Infections. Pediatr Infect Dis J. 2020;39(9):e245–e248.
4. Bradley JS, Broadhurst H, Cheng K, et al. Safety and Efficacy of Ceftazidime-Avibactam Plus Metronidazole in the Treatment of Children ≥3 Months to <18 Years With Complicated Intra-Abdominal Infection: Results From a Phase 2, Randomized, Controlled Trial. >Pediatr Infect Dis J. 2019;38(8):816–824.
5. Jackson CA, Newland J, Dementieva N, et al. Safety and Efficacy of Ceftolozane/Tazobactam Plus Metronidazole Versus Meropenem From a Phase 2, Randomized Clinical Trial in Pediatric Participants With Complicated Intra-abdominal Infection. Pediatr Infect Dis J. 2023;42(7):557–563.
6. Wirth S, Emil SGS, Engelis A, et al. Moxifloxacin in Pediatric Patients With Complicated Intra-abdominal Infections: Results of the MOXIPEDIA Randomized Controlled Study. Pediatr Infect Dis J. 2018;37(8):e207–e213.
7. Lee J, Garvey EM, Bundrant N, et al. IMPPACT (Intravenous Monotherapy for Postoperative Perforated Appendicitis in Children Trial): Randomized Clinical Trial of Monotherapy Versus Multi-drug Antibiotic Therapy. Ann Surg. 2021;274(3):406–410.
8. Armstrong J, Sriranjan J, Briatico D, et al. Piperacillin/tazobactam versus ceftriaxone/metronidazole for children with perforated appendicitis: a systematic review and meta-analysis. Pediatr Surg Int. 2025;42(1):3–z.
9. Pogorelić Z, Silov N, Jukić M, et al. Ertapenem Monotherapy versus Gentamicin Plus Metronidazole for Perforated Appendicitis in Pediatric Patients. Surg Infect (Larchmt). 2019;20(8):625–630.

 

Measles, a disease that was a rare occurrence in the recent past, has become much more common beginning in 2025. As I have received many questions about measles vaccine and treatment options, I thought it would be a good initial topic to discuss in early 2026.

Measles Cases Continuing to Increase

The incidence of measles in the US and many developed countries has been on the rise. In 2025 the US, the Centers for Disease Control and Prevention have noted 2276 cases in 44 states.¹ Most cases (68%) were in children, and the youngest children (<5 years old) have the highest rates of hospitalization (20%).¹ In early 2026, these increases continue with 733 cases by February 5, 2026.¹

Measles Vaccine is Very Effective

The measles, mumps, and rubella (MMR) vaccine is a very effective live attenuated vaccine.  One dose of MMR is about 90% effective and 2 doses 97%.^2,3  Without appropriate immunity (primarily obtained from vaccination), measles is very contagious, causing disease in more than 90% of exposed individuals.³

MMR vaccination is routinely recommended as a 2-dose series (dose 1 at 12-15 months of age, dose 2 at 4-6 years).^4-6 Doses as close as 28 days apart are considered valid.  The MMR vaccine is also recommended for susceptible individuals as young as 6 months of age during an outbreak (consult local public health for specifics) or in those planning international travel (doses given prior to 12 months of age do not count towards 2 routine dose recommendation).^7,8

How does measles disease present?

Measles has an initial prodrome when symptoms can be similar to a severe cold or flu with fever (often high), cough, runny nose, and conjunctivitis.^3,7 The characteristic Koplik spots may be present during the prodrome or may become present a day or two later. The rash, which begins in the head/facial area and spreads downward has been one of the most obvious symptoms of measles, does not present until 2-5 days into the illness. Thus, besides being very contagious, another reason patients transmit it to others is they may not think they have measles while they are most contagious. In healthy individuals, the infectious period is 4 days before and 4 days after the rash appears.^3,7

Measles can have complications and infants and young children are at risk for these. The most common complications include diarrhea, ear infections and pneumonia.³ Important, but rare complications include acute encephalitis as well as a late onset (7-10 years later) fatal complication of subacute sclerosing panencephalitis.³

What can I do if susceptible children are exposed?

Vaccines and measles immunoglobulin can be helpful at protecting exposed patients, if the patient is aware and can obtain it in time. The vaccine is the preferred recommendation (84 – 100% effectiveness) in non-immune eligible patients (i.e., ≥ 6 months and without contraindications) who were exposed in the prior 72 hours.^7,9 Immune globulin is recommended (76-100% effectiveness) for those who have a risk factor and are unable to receive the vaccine due to age (e.g., < 6 months), timing (e.g., > 72 hours but < 5 days), or contraindication to the vaccine (e.g., immunocompromise, pregnancy).^7,9

Are there any treatments for measles?

There are no antivirals that have efficacy against measles.  Data from a 2025 Cochrane review on the use of vitamin A for the treatment of measles, relied on limited studies published in the 1980’s and 1990’s.¹⁰ In their review of the studies they found that two doses of vitamin A at 200,000 IU did not result in overall lower risk of mortality; however, it was associated with lower mortality in young children (e.g., < 2 years) and in those who had measles associated pneumonia.¹⁰ It also had a slight reduction in measles croup.  The vitamin A was not, however, effective at preventing pneumonia and had only a non-significant impact on the duration of pneumonia.¹⁰

Summary

It is important to make sure that all are aware that measles is preventable by a highly effective routine immunization recommended in childhood.  Catch-up vaccination can be given to all those without protection as long as they do not have any contraindications.  When individuals contract measles disease there are no specific treatments, although a 2-dose series of vitamin A may help in some circumstances.

References

1. Centers for Disease Control and Prevention. Measles Cases and Outbreaks. Accessed February 6, 2026https://www.cdc.gov/measles/data-research/
2. Paul Gastanaduy, Penina Haber, Paul Rota, Manisha Patel. Chapter 13: Measles. In: Elisha Hall, A. Patricia Wodi, Jennifer Hamborsky, Valerie Morelli, Sarah Schille, eds. The Epidemiology and Prevention of Vaccine-Preventable DiseasesPublic Health Foundation; 2024
3. James L. Goodson and Thomas D. Filardo. Measles (Rubeola). In: Centers for Disease Control and Prevention (CDC), ed. CDC Yellow Book 2026: Health Information for International Travel.2026th ed. https://www.cdc.gov/yellow-book/hcp/travel-associated-infections-diseases/measles-rubeola.html
4. American Academy of Family Physicians. Immunization Schedules. Accessed December 12, 2025 https://www.aafp.org/family-physician/patient-care/prevention-wellness/immunizations-vaccines/immunization-schedules.html
5. American Academy of Pediatrics, Committee on Infectious Diseases. Red Book : Report of the Committee on Infectious Diseases 2024 – 2027. AAP Immunization Schedule. Accessed December 12, 2025 https://publications.aap.org/redbook/resources/15585/AAP-Immunization-Schedule
6. Centers for Disease Control and Prevention. Child and Adolescent Immunization Schedule by Age (Addendum updated August 7, 2025). Accessed September 20, 2025 https://www.cdc.gov/vaccines/hcp/imz-schedules/child-adolescent-age.html
7. Committee on Infectious Diseases, American Academy of Pediatrics. Measles. In: David W Kimberlin, Ritu Banerjee, Elizabeth D Barnett, Ruth Lynfield, Mark H. Sawyer, eds. Red Book: 2024–2027 Report of the Committee on Infectious Diseases (33rd Edition) American Academy of Pediatrics; 2024
8. Mathis AD, Raines K, Filardo TD, et al. Measles Update – United States, January 1-April 17, 2025. MMWR Morb Mortal Wkly Rep. 2025;74(14):232–238
9. Montroy J, Yan C, Khan F, et al. Post-exposure prophylaxis for the prevention of measles: A systematic review. Vaccine. 2025;47:126706
10. Huiming Y, Chaomin W, Meng M. Vitamin A for treating measles in children. Cochrane Database Syst Rev. 2005;2005(4):CD001479