New Hampshire Antibiograms

by S. Kelly last updated Jan 15, 2020 09:56 PM
NH susceptibility, DHPS, New Hampshire Public Health

See disclaimer.






Reporting Requirements:

Reporting requirements are governed by RSA 141:C6 with authority given to DHHS to develop administrative rules to provide specific reporting instructions and methodology. Administrative rules He-P 301 were adopted in fall 2016 “He-P 300 Diseases, PART He-P 301.02 Communicable Diseases,” were updated in 2016 with stakeholder input and approved by the Joint Legislative Committee on Administrative Rules. The updated rules require hospital laboratories to report antibiogram data annually to the State of New Hampshire.

Collection Process and Validation:

NH DPHS developed a standardized antibiogram fillable form for reporting susceptibility data, and requested data from hospital microbiology laboratories in January 2018. This form was developed to encompass most relevant antibiotic and organism combinations, created in collaboration between the NH DPHS and stakeholder subject matter experts. All 26 NH hospitals reported antibiogram data as required under He-P301; along with the Veteran’s Affairs Hospital whom voluntarily reported data.

The HAI Program reconciled data to confirm reported data and evaluate accuracy and reliability of the data. The HAI Program first conducted an internal assessment to identify outliers or implausible data by comparing the percent susceptibilities between all hospitals for every organism and antibiotic combination and then corrected or confirmed data with each respective microbiology laboratory. The program subsequently convened an infectious disease medical and pharmacy advisory group to review the clinical implications of the data and ensure data was clinically accurate and relevant. The advisory group determined which antibiotic-organism combinations to censor due to clinical inappropriateness. Lastly, the antibiogram data was reviewed by the NH Antimicrobial Resistance Advisory Workgroup (ARAW) to provide feedback and suggestions for use.

Antibiogram Development:

The Clinical and Laboratory Standards Institute (CLSI) guidelines were followed in the aggregation of data from all reported hospital antibiograms. Antibiotic and organism combinations that are either intrinsically resistance or not clinically appropriate were censored from the antibiogram. Per CLSI guidelines, any antibiotic and organism combination with a total number of isolate counts of less than 30 isolates were excluded.
An ARAW subcommittee, made up of infectious disease clinical specialists, drafted and reviewed the antibiogram executive summary to assist with clinical interpretation. The summary focused on treatment of common infections syndromes and was based on review of NH antibiogram data and current national treatment guidelines (

Data Limitations

  • Due to the variation in breakpoints used by clinical laboratories to interpret antibiotic susceptibility results there may be discrepancies between laboratory reported susceptibility results.
  • Antibiotic susceptibility data from regional reference labs is not included in this data set and therefore the antibiogram is limited in its representativeness to hospital laboratory isolates.
  • The urine only antibiogram includes all urine isolates, not necessarily only those pertaining to urinary tract infections. These isolates may represent other types of infections where bacteria were cultured from other clinical isolates in addition to the urine (e.g. bacteremia with seeding of the urine).
  • The lack of reported susceptibility results for an antibiotic against a specific organism doesn’t necessarily mean that the antibiotic isn’t active. In some cases activity is reliably predicted by the activity of another agent (e.g. cefazolin activity against Staphylococcus aureus is predicted by oxacillin susceptibility); while in some other cases it is not possible to test susceptibility due to lack of testing reagents. Conversely, reported activity on in vitro susceptibility results does not necessarily mean an agent is clinically effective (or as effective as alternatives). For example, ciprofloxacin may show in vitro activity against Staphylococcus aureus, but ciprofloxacin should never be used to treat infections caused by this organism. This is because of the potential for rapid development of resistance while being treated with ciprofloxacin.
  • The values presented in the antibiogram are rounded and do not show exact values.


All the data in this report are based upon information provided to the New Hampshire Department of Health and Human Services under specific legislative authority. The numbers reported may represent an underestimate of the true absolute number in the state. Any release of personal identifying information is conditioned upon such information remaining confidential. The unauthorized disclosure of any confidential medical or scientific data is a misdemeanor under New Hampshire law. The department is not responsible for any duplication or misrepresentation of surveillance data released in this report. Data are complete as of 1/13/20. Report prepared by the Healthcare-Associated Infections Program, Infectious Disease Surveillance Section,, (603)-271-4496.


We would like to first and foremost thank the clinical microbiologists who submitted antibiogram data on behalf of their healthcare facility; without their efforts this report would not be possible. We would also like to thank the ARAW for their time and input that contributed directly to the creation and clinical content outlined in this report. Their work has been invaluable:

  • Trevor Bauer, MPH
  • Michael Calderwood, MD, MPH
  • Benjamin Chan, MD, MPH
  • Maureen Collopy, MPH, MT(ASCP)
  • Apara Dave, MD
  • Rachel Gridley, BS
  • Katrina Hansen, MPH
  • Jonathan Napoli, PharmD, MHA, BPS
  • Yvette Perron, MPH
  • Erin Reigh, MD, MS
  • Paul Santos, PharmD
  • Elizabeth Talbot, MD
  • Daniel Tullo, MS, SM (ASCP)
  • Joshua White, MD
  • Carly Zimmermann, MPH, MLS(ASCP)cm
  • Melissa Deveau, MsPH, MLS(ASCP)cm

The NH DPHS HAI Program is a resource for guidance in developing and strengthening your facilities stewardship program. Please contact us at or (603) 271-4496.