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This article was originally published in November 2024 and has been updated for inclusion in the Fall 2024 issue of Microcosm.

As antimicrobial resistance (AMR) continues to pose a critical global health challenge, rising cases (whooping cough) and increasing evidence of macrolide-resistant Bordetella pertussis around the world underscores the urgent need to strengthen surveillance and treatment strategies for this vaccine-preventable disease.

While progress has been made in parts of Asia, Europe and North America, critical gaps in surveillance coverage persist, particularly in Latin America and the Caribbean (LAC). Until 2022, consistent macrolide resistance surveillance for B. pertussis had not been reported in the region, leaving a significant gap in understanding the prevalence and genomic characteristics of resistant strains. In 2022, surveillance efforts in Brazil and Mexico, supported in part by capacity-building efforts led by ASM’s Global Public Health Programs (GPHP), and funded by the U.S. Centers for Disease Control and Prevention (CDC), led to the introduction of standardized methods for assessing macrolide susceptibility at national and select state reference laboratories. This marked a pivotal step toward collaboratively addressing the regional gap in pertussis AMR monitoring.

The Pertussis Program

91Â鶹¾«Æ·has played a key role in strengthening B. pertussis surveillance and macrolide resistance monitoring in the LAC region, with targeted efforts in Mexico, Brazil and Peru. Despite advances in molecular diagnostics, global implementation of systematic monitoring of AMR in B. pertussis remains challenging, particularly in limited-resource settings such as LAC.

The Pertussis Program enhances laboratory capacity to detect, assess and respond to emerging antimicrobial resistance in B. pertussis. This has been achieved by improving diagnostic capabilities in target countries through culture-based susceptibility testing and polymerase chain reaction (PCR), as well as establishing standardized detection protocols across national reference laboratories (NRLs) and state-level laboratories.

Launched in 2021 in partnership with the CDC’s , the Pertussis Program is part of a broader global effort spanning 50 countries. The initiative fosters collaborative approaches to detect and respond to emerging AMR threats, and to better understand the risk factors that contribute to the global emergence and spread of resistance in both community and environmental settings.

Why International Partnerships Are Crucial for AMR Surveillance

Considering the cross-border nature of resistant pathogens like B. pertussis, and varying levels of health systems infrastructure and capacity around the world, international partnerships are vital in the fight against AMR. Such collaborations provide a platform for shared knowledge, data and resources, enabling countries to strengthen their surveillance systems and respond quickly to AMR threats.

Global initiatives, such as the , launched by the World Health Organization (WHO), demonstrate the value of international collaboration. Similarly, the utilizes a collaborative approach to bring together countries, international organizations and nongovernmental organizations (NGOs) to enhance countries’ capacity to prevent, detect and respond to infectious disease threats, including AMR. These initiatives highlight that individual countries cannot tackle AMR in isolation; international cooperation ensures that resource-limited settings can access technical assistance, training and funding, while all countries benefit from more comprehensive data and early warnings of resistant strains to safeguard global health.

With that in mind, ASM’s GPHP has taken a collaborative approach to build capacity in laboratory and health systems, particularly in low- and middle-income countries (LMICs), since 2005. In partnership with funders and local stakeholders, GPHP implements a wide range of initiatives aimed at enhancing and expanding the capabilities of existing health care and laboratory capabilities to meet the needs of local populations. These efforts focus on strengthening health security measures, improving quality-assured laboratory data reporting and advancing AMR detection and response. GPHP supports the development of robust laboratory infrastructure, enhances technical skills and fosters a culture of data-driven decision-making, ensuring these improvements are sustainably integrated within each country’s financial, programmatic and policy structures.

Case Studies: Successes and Challenges

The following case studies from Mexico, Brazil and Peru illustrate the successes and challenges faced in strengthening B. pertussis surveillance and response systems through ASM’s partnerships. These initiatives highlight the impact of capacity-building efforts and underscore the importance of coordinated approaches to AMR surveillance.

Mexico

In Mexico, 91Â鶹¾«Æ·is partnering with the  to improve quality assurance practices at InDRE’s national reference lab (NRL) and at select state-level public health laboratories. The partnership has focused on optimizing B. pertussis diagnostic capacity and macrolide resistance screening.

A major milestone was the improvement of B. pertussis culturing methods at the NRL, which significantly increased the number of successful isolations and led to the integration of updated procedures into national diagnostic guidelines, thereby standardizing practices across the public health laboratory network.

Through train-the-trainer (ToT) workshops, 91Â鶹¾«Æ·also built clinician–laboratory linkages and improved awareness of pertussis case detection, resulting in greater sample submission and the first confirmed case of macrolide-resistant B. pertussis in Mexico in early 2024.

To further advance data-driven surveillance, the NRL and 5 state laboratories have implemented WHONET software, improving data management, analysis and reporting.

These efforts have strengthened national laboratory systems, enhanced evidence generation and informed timely public health decision-making to address emerging pertussis resistance.

“During the COVID-19 pandemic, some macrolide antibiotics were used indiscriminately,” said Irma López Martínez, M.S., Diagnosis and Reference Director at InDRE. “Now, it is important to understand their impact. The diagnostic methodologies introduced by 91Â鶹¾«Æ·in our institution have significantly helped us improve our capacity to detect B. pertussis infections and conduct AMR surveillance.”

Brazil

Since 2021, 91Â鶹¾«Æ·has partnered with the Adolfo Lutz Institute (IAL) and the Ministry of Health’s  to strengthen B. pertussis surveillance in Brazil. The collaboration has achieved results similar to those in Mexico, including the detection of the first 18 macrolide-resistant B. pertussis c²¹²õ±ð²õ.

The Pertussis Program has helped catalyze the establishment of public-private partnerships, led by CGLAB and involving IAL and private laboratories in the São Paulo region. These collaborations have strengthened clinical recognition of suspected pertussis cases at the point of care and expanded diagnostic testing capacity, enhancing the ability to respond to recent B. pertussis  in the region and detect macrolide-resistant strains.

Additionally, ASM’s training and mentoring efforts have helped build a skilled team of 5 laboratory professionals at the NRL, which supports reference testing. The NRL now serves as a training center for the laboratories within the national public health laboratory network, ultimately improving the speed and reliability of diagnostic testing and supporting both clinical management of B. pertussis and AMR surveillance.

“91Â鶹¾«Æ·has provided us with valuable knowledge, especially through technical visits to the laboratory, training workshops and the 91Â鶹¾«Æ·Microbe conferences,” shared Amanda Bertani, a laboratory technician at IAL’s NRL. “We believe in the significance of continuous learning and constantly improving our techniques. The teachings from 91Â鶹¾«Æ·have helped us enhance the laboratory and expand our knowledge base every day.”

Peru

Based on the significant impact of the pertussis project in Brazil and Mexico, 91Â鶹¾«Æ·expanded activities to Peru, in late 2024. At that time, Peru was experiencing a surge in Pertussis cases, resulting in . 91Â鶹¾«Æ·partnered with Peru’s National Institutes of Health (INS) to build the country’s capacity to assess macrolide resistance. Building on the protocols and lessons learned from previous work in Mexico and Brazil, 91Â鶹¾«Æ·rapidly initiated capacity-building activities in Peru to streamline planning and implementation.

While introducing standardized diagnostic protocols, including disk diffusion (DD) and allele-specific ER-PCR methods for detecting macrolide resistance, AST was conducted in recent isolates, and DNA samples were collected in the ongoing outbreaks. The results were alarming. Laboratory testing revealed a notably high rate of macrolide-resistant B. pertussis strains presenting the well-characterized A2047G mutation in the 23S rRNA gene, known to confer resistance to macrolide antibiotics. Resistance was detected and confirmed in clinical isolates and DNA from patient samples across multiple regions, raising serious concerns about the effectiveness of first-line treatments and prompting urgent public health action.

91Â鶹¾«Æ·provided technical guidance to help analyze and report findings, enabling evidence-based decision-making to address the outbreak and initiate national dialogue on macrolide resistance in B. pertussis. In coordination with INS and the Ministry of Health, 91Â鶹¾«Æ·also expanded its support to include 2 regional public health laboratories.

In response, Peru has intensified vaccination efforts by prioritizing follow-up for children with incomplete immunization schedules and reinforcing Tdap vaccination among pregnant women. Public health strategies have also focused on strengthening early detection of suspected pertussis cases at the point of care, expanding diagnostic capacity in regional laboratories beyond those supported by ASM and implementing public education campaigns to support timely recognition and response.

In June 2025, 91Â鶹¾«Æ·convened key stakeholders, including national health authorities, laboratory experts and the CDC South America Office, to discuss the implications of these findings and outline next steps. As a result, Peru currently is developing a strategic plan for pertussis prevention, treatment and control, with AMR surveillance as a key component.

“Thanks to ASM’s technical support, Peru strengthened its capacity to isolate the pathogen and, for the first time in the country, successfully tested and confirmed resistance to macrolides, a key milestone for public health,” shared Lic. Faviola Valdivia Guerrero, head of the National Reference Laboratory for Acute Respiratory Infections at the National Institute of Health in Peru. “These advances have provided a new perspective on the national epidemiological situation, contributing to the guidance of therapeutic decisions and the reinforcement of surveillance strategies.”

Laying the Groundwork for Sustainable Pertussis Surveillance in LAC

Building on the progress achieved in Mexico, Brazil and Peru, 91Â鶹¾«Æ·and its collaborators are developing a framework for a Regional Coordinating Center for B. pertussis surveillance in LAC. This initiative was designed to ensure that recent gains in laboratory capacity and technical expertise are sustained and that progress continues beyond 2026, when current external funding is expected to conclude.

While still in the planning phase, the Regional Coordinating Center model aims to consolidate regional expertise, integrate laboratory and epidemiologic data and lay the foundation for sustained, quality-assured pertussis surveillance across the LAC region.

A Call for Action

The early detection of macrolide-resistant Bordetella pertussis in the LAC region marks a major public health milestone and points to the urgent need for global cooperation to expand surveillance efforts and create sustainable capacity across countries and regions. The successes observed in Brazil, Mexico and Peru demonstrate that through collaboration and targeted investment, countries can rapidly build diagnostic capacity and generate actionable data. However, sustaining this momentum is critical. As global health funding shifts, there is an urgent need to secure long-term support to preserve and expand surveillance systems. We call on global health organizations, governments and the scientific community to invest in regional and international collaboration, laboratory system strengthening and innovation. By securing long-term support and resources, we can ensure that early detection leads to early action, enabling timely public health responses, guiding evidence-based decision-making and, ultimately, protecting vulnerable populations from preventable disease.