Azithromycin for Meningococcal Carriage

Effectiveness of Azithromycin in Eradicating Nasopharyngeal Carriage of N. Meningitidis

The purpose of this study is to determine the effectiveness of azithromycin in the eradication of nasopharyngeal carriage of N. meningitidis

Study Overview

• Status: Completed
• Conditions: Meningococcal Infections
• Intervention / Treatment: Drug: Azithromycin

Detailed Description

Azithromycin belongs to the class of antimicrobials known as macrolides. They are approved for the treatment of a wide variety of infections, including community-acquired respiratory tract infections and sexually transmitted infections caused by different bacteria. Their mechanism of action is dependent on bacterial ribosomal binding, leading to inhibition of bacterial protein synthesis. Azithromycin has a broad spectrum of activity to include Gram-positive and Gram-negative organisms, as well as atypical and mycobacterial organisms.

A single oral dose of 500mg of azithromycin has been shown to eradicate N. meningitidis colonization. Historically, azithromycin has not been recommended as first-line chemoprophylaxis for close contacts of patients with invasive meningococcal disease (IMD) since it has not been well studied for this indication. A study from 2020 evaluated the activity of azithromycin against 205 invasive N. meningitidis isolates and found that 100% were susceptible according to Clinical and Laboratory Standards Institute (CLSI) breakpoints. Moreover, with the rise in cases of meningococcal disease caused by ciprofloxacin-resistant strains, the Centers for Disease Control and Prevention (CDC) recently updated their guidance to health department for when to consider other options (including azithromycin).

Participants identified as carriers of N. meningitidis will be asked to take a one-time oral dose of azithromycin, 500mg (standard dose).

• Study Type: Interventional
• Enrollment (Actual): 764
• Phase: Phase 2

Contacts and Locations

Study Locations

• United States
  • Georgia
    • Decatur, Georgia, United States, 30030
      • Hope Clinic of the Emory Vaccine Center

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Able to provide their own informed consent and understand study procedures
• Undergraduate and graduate students attending Emory University affiliated campuses who reside in university affiliated housing (for undergraduate/graduate) or in off-campus housing (undergraduates).

Exclusion Criteria:

• University faculty and staff
• Currently pregnant or breast feeding
• History of immediate or moderate-to-severe allergic reactions to azithromycin
• Individuals who have taken systemic antibiotics for any reason in the 30 days prior to enrollment
• Individuals with any symptoms of acute illness at the time of screening

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Azithromycin; Persons with microbiologic documentation of N. meningitidis carriage will receive a single, standard dose of azithromycin.	Drug: Azithromycin; A standard dose of azithromycin (500 mg) will be delivered by oral route.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Eradication of N. meningitidis carriage	Eradication of N. meningitidis carriage is defined as positive culture at the second visit (immediately prior to azithromycin administration) and negative culture approximately 2 weeks after antibiotic administration.	Day 7 (immediately prior to azithromycin administration) and Day 21 (2 weeks after azithromycin administration)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Proportion of Participants Culture-Positive	Carriage prevalence is examined as the proportion of participants who are culture-positive at the initial visit, by serogroup and meningococcal vaccination status.	Day 1 (screening visit)
Risk Factors for Meningococcal Carriage	Risk factors contributing to meningococcal carriage will be assessed by administering a survey to participants asking about their meningococcal vaccination status, recent antibiotic use, recent respiratory illness, smoke exposure and other social behaviors, with responses given in a "yes" or "no" format.	Day 1 (screening visit)
Minimal Inhibitory Concentrations (MICs) for Ciprofloxacin	The minimum inhibitory concentrations (MICs) are the lowest concentration of an antimicrobial that will inhibit the visible growth of a microorganism following overnight incubation. The MICs for ciprofloxacin among meningococcal isolates before and after azithromycin administration will be examined.	Day 7 (immediately prior to azithromycin administration), Day 21 (2 weeks after azithromycin administration)
Minimal Inhibitory Concentrations (MICs) for Rifampin	The minimum inhibitory concentrations (MICs) are the lowest concentration of an antimicrobial that will inhibit the visible growth of a microorganism following overnight incubation. The MICs for rifampin among meningococcal isolates before and after azithromycin administration will be examined.	Day 7 (immediately prior to azithromycin administration), Day 21 (2 weeks after azithromycin administration)
Minimal Inhibitory Concentrations (MICs) for Ceftriaxone	The minimum inhibitory concentrations (MICs) are the lowest concentration of an antimicrobial that will inhibit the visible growth of a microorganism following overnight incubation. The MICs for ceftriaxone among meningococcal isolates before and after azithromycin administration will be examined.	Day 7 (immediately prior to azithromycin administration), Day 21 (2 weeks after azithromycin administration)
Minimal Inhibitory Concentrations (MICs) for Azithromycin	The minimum inhibitory concentrations (MICs) are the lowest concentration of an antimicrobial that will inhibit the visible growth of a microorganism following overnight incubation. The MICs for azithromycin among meningococcal isolates before and after azithromycin administration will be examined.	Day 7 (immediately prior to azithromycin administration), Day 21 (2 weeks after azithromycin administration)

Collaborators and Investigators

• Sponsor: Emory University
• Collaborators: Centers for Disease Control and Prevention; Georgia Department of Public Health
• Investigators: Principal Investigator: Paulina Rebolledo, MD, MSc, Emory University

Study record dates

Study Major Dates

• Study Start (Actual): November 12, 2024
• Primary Completion (Actual): April 29, 2026
• Study Completion (Actual): April 29, 2026

Study Registration Dates

• First Submitted: September 26, 2024
• First Submitted That Met QC Criteria: September 26, 2024
• First Posted (Actual): October 1, 2024

Study Record Updates

• Last Update Posted (Actual): June 5, 2026
• Last Update Submitted That Met QC Criteria: June 4, 2026
• Last Verified: June 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Infections; Bacterial Infections; Bacterial Infections and Mycoses; Gram-Negative Bacterial Infections; Neisseriaceae Infections; Meningococcal Infections; Organic Chemicals; Macrolides; Lactones; Erythromycin; Polyketides; Azithromycin
• Other Study ID Numbers: STUDY00008433; CDC-STUDY00008433 (Other Identifier: Centers for Disease Control and Prevention); 2025P012505 (Other Identifier: Emory IRB)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: Bacterial genome sequences will be deposited in "Public databases for molecular typing and microbial genome diversity" (PubMLST).
• IPD Sharing Time Frame: Individual participant data will be available for sharing following publication of results from this study, with no end date.
• IPD Sharing Access Criteria: Data will be made available for sharing with anyone who wishes to access the data, for any purpose. Data will be accessed via https://pubmlst.org/
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No