ORIGINAL ARTICLE

Introducción

Throughout history, the world has faced devastating epidemics and pandemics with significant consequences for global health, the economy, and social structures. Various factors have contributed to the rapid spread of infectious diseases, including increased travel, international trade, migration, accelerated urbanization, population growth, and rising population density.

Additionally, inadequate or insufficient health infrastructure, along with deficiencies in sanitation and access to safe drinking water in densely populated urban areas, exacerbate these risks. Other contributing factors include human-animal interaction, invasion of natural habitats, deforestation, and the wildlife trade—all of which are linked to the spread of zoonotic diseases. Some of these diseases have been associated with the emergence of highly lethal pathogens, such as SARS-CoV-2 (the cause of COVID-19) and the Ebola virus, among others <sup>1 ➤
1. 1. Vora NM, Hannah L, Walzer C, Vale MM, Lieberman S, Emerson A, et al. Interventions to Reduce Risk for Pathogen Spillover and Early Disease Spread to Prevent Outbreaks, Epidemics, and Pandemics. Emerg Infect Dis. 2023;29(3):1-9. doi:10.3201/eid2903.221079.</sup> – ^{1-3 ➤
1-3. 3. Hotez PJ. Global urbanization and the neglected tropical diseases. PLoS Negl Trop Dis. 2017;11(2):e0005308. doi:10.1371/journal.pntd.0005308.} .

Climate change also influences the spread of communicable diseases by altering geographic distribution and increasing the prevalence of vector-borne diseases such as malaria and dengue. These diseases have expanded into new regions, posing a growing challenge to global public health <sup>4 ➤
4. 4. Patz JA, Thomson MC. Climate change and health: Moving from theory to practice. PLoS Med. 2018;15(7):e1002628. doi:10.1371/journal.pmed.1002628.</sup> .

In May 2005, the World Health Organization (WHO), during the 58th World Health Assembly, adopted the International Health Regulations (IHR-2005) in response to increasing international travel and trade, as well as the emergence and re-emergence of diseases and other public health threats with global impact. This legally binding regulation came into force on June 15, 2007, and establishes the criteria and mechanisms for declaring a Public Health Emergency of International Concern (PHEIC) <sup>5 ➤
5. 5. Organización Mundial de la Salud. Reglamento sanitario internacional (2005) [Internet]. 3a ed. Ginebra: Organización Mundial de la Salud; 2016 [citado 14 de julio de 2024]. 93 p. Disponible en: https://iris.who.int/handle/10665/246186.</sup> .

A PHEIC is formally declared by the WHO and defined as “an extraordinary event which is determined to constitute a public health risk to other States through the international spread of disease and to potentially require a coordinated international response.” For such a declaration, the event must meet specific criteria: it must be “serious, sudden, unusual or unexpected,” have “public health implications beyond the affected State’s borders,” and “potentially require immediate international action.” In such cases, States have a legal obligation to respond promptly ^{6-8 ➤
6-8 6. WHO. Emergencies: International health regulations and emergency committees [Internet]. 2019 [citado 13 de julio de 2024]. Disponible en: https://www.who.int/news-room/questions-and-answers/item/emergencies-international-health-regulations-and-emergency-committees.} – <sup>8 ➤
8. 8. Mullen L, Potter C, Gostin LO, Cicero A, Nuzzo JB. An analysis of International Health Regulations Emergency Committees and Public Health Emergency of International Concern Designations. BMJ Glob Health. 2020;5(6):e002502. doi:10.1136/bmjgh-2020-002502.</sup> .

In Peru, following the implementation of IHR-2005, a process began to evaluate core surveillance and response capacities, followed by their implementation. These capacities are periodically assessed using standardized self-assessment tools and annual reports submitted by Member States to the WHO <sup>9 ➤
9. 9. WHO. Reglamento sanitario internacional (2005): instrumento de autoevaluación para la presentación anual de informes de los estados partes. 2a ed. [Internet]. 2022 [citado 16 de julio de 2024]. Disponible en: https://cdn.who.int/media/docs/default-source/health-security-preparedness/cap/spar/9789240046245-spa.pdf?sfvrsn=7d7a7c8d_7.</sup> . The goal is to ensure that the country has the necessary means to detect, assess, and report any potential public health event of international concern, and to respond effectively and in a timely manner.

The declaration of a PHEIC by the WHO draws international attention and prompts responses from governments, the media, and the general population. It also acts as a global alert for a potential epidemic or pandemic, mobilizing large-scale public health management strategies. These strategies include quarantines, travel restrictions, and public health education and communication campaigns, aimed at guiding the population to adopt preventive measures against the identified causal agent <sup>10 ➤
10. 10. Yin JDC, Lui JNM. Factors influencing risk perception during Public Health Emergencies of International Concern (PHEIC): a scoping review. BMC Public Health. 2024;24(1):1372. doi:10.1186/s12889-024-18832-z.</sup> .

Since the adoption of IHR-2005, the WHO has declared eight PHEICs, each with varying impacts in Peru, testing the country's surveillance and response capabilities. This article aims to analyze the health impact of PHEICs and Peru’s response within the IHR-2005 framework.

Métodos

Study Design
This is a descriptive study based on event reports. A documentary analysis was conducted using secondary data sources, including a collection and review of the PHEICs declared by the WHO from the adoption of IHR-2005 to date. The impacts of these emergencies on the country were analyzed in various aspects, including public health, reflected in indicators such as morbidity, mortality, case fatality, and implementation of response measures.

Variables and Data Sources.
The following variables were analyzed: name of the PHEIC, origin, identified causative agent, date of declaration, global evolution, end date, place and date of introduction in Peru, time elapsed between the PHEIC declaration and confirmation of the first case in the country, health impact in terms of incidence, mortality, and case fatality, as well as the main response measures implemented.

The units of analysis were the PHEICs declared by the WHO. The period of analysis ranged from 2005 to September 2024. Data sources included publications from international organizations such as the WHO and the Pan American Health Organization (PAHO), as well as national institutions such as the Centro Nacional de Epidemiología, Prevención y Control de Enfermedades (National Center for Epidemiology, Disease Prevention and Control), the Ministry of Health, and the Government of Peru.

Data on cases and deaths from Influenza A(H1N1)-2009 were obtained from the article “Mortality related to Influenza A H1N1 in Peru during the 2009-2010 pandemic” <sup>11 ➤
11. 11. Suárez-Ognio L, Arrasco J, Gómez J, Munayco C, Vílchez A, Cabezas C, et al. Mortalidad relacionada a influenza AH1N1 en el Perú durante la pandemia en 2009-2010. Revista Peruana de Epidemiología. 2011;15(1):24-30. Disponible en: https://www.redalyc.org/articulo.oa?id=203119644004.</sup> . COVID-19 death figures were extracted from the Open Data Platform of the Government of Peru <sup>12 ➤
12. 12. Gobierno del Perú. Plataforma de Datos Abiertos: de COVID-19. [Internet]. 2020 [citado 19 de julio de 2024]. Disponible en: https://www.datosabiertos.gob.pe/group/datos-abiertos-de-covid-19.</sup> , and Monkeypox cases were obtained from the PAHO website “Mpox cases - Americas Region” <sup>13 ➤
13. 13. OPS. Mpox cases - Americas Region [Internet]. 2023. [citado 21 de julio de 2024]. Disponible en: https://shiny.paho-phe.org/mpox/</sup> .

Additionally, population estimates for the year each PHEIC was declared were provided by the Instituto Nacional de Estadística e Informática del Perú (National Institute of Statistics and Informatics) of Peru.

Health impact indicators included the calculation of the cumulative incidence rate (CIR), cumulative mortality rate (CMR), and cumulative case fatality rate (CFR).

Data Analysis
The data were organized in an Excel spreadsheet. A univariate descriptive analysis was performed by counting cases by type of event and calculating incidence, mortality, and case fatality rates. Response measures implemented for each event type were also summarized descriptively. Results are presented in tables and figures.

The CIR was calculated as: (Total number of cases during the PHEIC / estimated population in the year the PHEIC was declared) x 1000. The CMR was calculated as: (Total number of deaths during the PHEIC / estimated population in the year the PHEIC was declared) x 1000. The CFR was calculated as: (Total number of deaths during the PHEIC / Total number of cases during the PHEIC) x 100. Crude rates at the national level were calculated without any adjustments.

Ethical Considerations
This study was based on publicly accessible information sources. Since the analysis focused on events and did not involve variables or data that could identify individuals, approval from an institutional ethics committee was not required.

Results

Since the adoption of IHR-2005 until August 2024, the WHO has declared eight PHEICs:

Influenza A(H1N1)-2009 (2009–2010).
This was the first PHEIC declared by the WHO. Initially detected as clusters of respiratory syndrome cases in Mexico and the United States, the causative agent was a new subtype of Influenza A(H1N1), which spread rapidly and led the WHO to declare it a PHEIC on April 25, 2009. In Peru, the first case was confirmed two weeks after the declaration, and the first death occurred a month later. In June 2009, the WHO declared a pandemic, which lasted until August 2010. The country implemented strategies for timely detection and pandemic control (Tables 1 and 2). The disease affected all regions of the country, with confirmed cases and deaths (Figure 1).

Poliomyelitis (2014 - present).
In 2014, the spread of wild poliovirus from Pakistan to Afghanistan, from Syria to Iraq, and from Cameroon to Equatorial Guinea, along with outbreaks in Ethiopia, Israel, Somalia, and Nigeria, led the WHO to declare this PHEIC in May 2014. It is the longest-running PHEIC to date. In Peru, response actions focused on strengthening epidemiological surveillance and improving vaccination coverage (Tables 1 and 2).

Ébola (2014-2016).
Ebola virus disease (EVD) emerged in December 2013 in a village in Guinea and was declared a PHEIC eight months later after cross-border spread to three other countries. The WHO declared the end of the emergency in June 2016. No EVD cases were reported in Peru; however, preparedness and response actions were carried out for potential imported cases (Tables 1 and 2).

Zika (2016).
Following reports of microcephaly cases associated with the Zika virus in Brazil, the WHO declared a PHEIC on February 1, 2016. The emergency was declared over in November that same year. No confirmed cases were reported in Peru during the PHEIC period; however, epidemiological surveillance strategies for congenital malformations, prevention, and monitoring of infected pregnant women were implemented, with a focus on areas of previous outbreaks (Tables 1 and 2).

Ebola (2019 – 2020).
In 2019, the WHO declared a new EVD PHEIC following confirmation of an outbreak in the Democratic Republic of the Congo, which became the second-largest recorded since the virus was identified in 1976. On June 25, 2020, the WHO declared the end of the emergency due to reduced case numbers. No cases were reported in Peru, but preparedness actions were reinforced based on lessons from the 2014–2016 PHEIC (Tables 1 and 2).

COVID-19 (2020-2023). COVID-19 emerged in December 2019 with the detection of atypical pneumonia cases in Wuhan, China. The identified causative agent was SARS-CoV-2. The WHO declared it a PHEIC on January 30, 2020, and a pandemic on March 11 of the same year. In Peru, the first case was confirmed on March 6, 2020, and the first death was reported three days later. The pandemic spread across all regions of the country. In response, a national health emergency was declared, and measures such as epidemiological surveillance, contact tracing, lockdowns, infection prevention, and case management according to severity were implemented (Tables 1 and 2, Figure 1). The WHO declared the end of the emergency on May 5, 2023.

Monkeypox (2022-2023).
The Monkeypox virus was first detected in humans in the Democratic Republic of the Congo in 1970 and was considered endemic in some African countries. However, between 2018 and 2021, cases were reported in the United Kingdom, Portugal, and Singapore, associated with travel after a Nigerian outbreak. The WHO declared it a PHEIC on July 23, 2022, after the disease spread to over 100 countries. The emergency ended on May 11, 2023, due to a decline in cases.

In Peru, the first case was confirmed on June 26, 2022, and cases were reported in all regions during the PHEIC period (Figure 1). In response, epidemiological surveillance, case and complication management, infection prevention and control in healthcare settings, and vaccination of at-risk groups were implemented (Tables 1 and 2).

Monkeypox (2024 - present).
On August 14, 2024, the WHO once again declared Monkeypox (Mpox) a PHEIC due to rising cases in the Democratic Republic of the Congo and other African countries. The rapid spread of the virus, the identification of a new strain (Clade 1b), and its predominant transmission through sexual networks were key factors in the declaration. In Peru, after the end of the 2022 PHEIC, confirmed cases continued to appear, and surveillance and response measures remain ongoing

Figure 1

Distribution of Public Health Emergencies of International Concern (PHEIC) at the departmental level in Peru.

DISCUSSION

The declaration of the Influenza A(H1N1)-2009 pandemic in 2009 as a PHEIC was the first of its kind under the IHR-2005 framework. Since then, the WHO has declared seven additional PHEICs: poliomyelitis, Ebola (2014), Zika (microcephaly), Ebola (2018–2020), COVID-19, Monkeypox (2022), and Monkeypox (2024) <sup>30 ➤
30. 30. Arrasco J. Enfermedades emergentes y reemergentes en el Perú en las últimas dos décadas, 2004-2023. Boletín Epidemiológico del Perú. 2023;32(30):724-30. Disponible en: https://www.dge.gob.pe/epipublic/uploads/boletin/boletin_202330_06_180823.pdf</sup> . Among these, Influenza A(H1N1)-2009 and COVID-19 evolved into pandemics. PHEICs are events that affect public health in their regions of origin and, due to global interconnectivity, can pose risks to populations worldwide, as observed over the past fifteen years.

In Peru, the first case of Influenza A(H1N1)-2009 was identified 15 days after the PHEIC declaration, while the first case of COVID-19 was confirmed 35 days after its declaration. These are relatively short intervals compared to earlier pandemics, such as the 1957 influenza, which reached Peru five months after its onset <sup>31 ➤
31. 31. Bennett B, Carney T. Public Health Emergencies of International Concern: Global, Regional, and Local Responses to Risk. Med Law Rev. 2017;25(2):223-39. doi:10.1093/medlaw/fwx004.</sup> . This phenomenon can be explained by increased human mobility, facilitated by air travel, which accelerates the spread of emerging and reemerging infectious diseases, increasing their impact on global health security <sup>32 ➤
32. 32. MINSA-Perú. Plan nacional de preparación y respuesta frente a una potencial pandemia de influenza. [Internet]. 2005 [citado 13 de agosto de 2024]. Disponible en: https://cdn.www.gob.pe/uploads/document/file/391093/Plan_nacional_de_preparaci%C3%B3n_y_respuesta_frente_a_una_potencial_pandemia_de_influenza20191017-26355-1lzyjau.pdf</sup> .

The Influenza A(H1N1)-2009 pandemic posed a challenge for surveillance and response in Peru, as it was the first PHEIC faced after the adoption of IHR-2005, during a period when epidemiological surveillance capacities were still being developed. According to the Pan American Health Organization (PAHO), by the end of the PHEIC, the pandemic H1N1-2009 virus had spread to all WHO regions and nearly every country, with an official record of approximately 18,500 deaths. Currently, the virus circulates seasonally, and surveillance and vaccination efforts are focused on prioritized population groups <sup>15 ➤
15. 15. OPS/OMS. La OMS declara el fin de la pandemia H1N1 e insta a una vigilancia continua de la gripe [Internet]. 2010 [citado 17 de julio de 2010]. Disponible en: https://www.paho.org/es/noticias/10-8-2010-oms-declara-fin-pandemia-h1n1-e-insta-vigilancia-continua-gripe.</sup> . However, data from surveillance systems such as Peru’s show significant underreporting compared to global estimates.

Epidemics and pandemics caused by respiratory viruses have a major impact on the social and economic activity of countries, as social distancing is one of the main prevention and control strategies. During the Influenza A(H1N1)-2009 pandemic, schools, sporting events, and cultural activities were suspended, significantly affecting economic productivity.

Poliomyelitis is a highly infectious disease, with one in every 200 cases leading to paralysis. Wild poliovirus type 1 (WPV1) is responsible for poliomyelitis epidemics, while types 2 and 3 have been globally eradicated. In Peru, the last case of wild poliovirus was reported in 1991 in Junín, which was also the last recorded case in the Americas <sup>33 ➤
33. 33. Findlater A, Bogoch II. Human Mobility and the Global Spread of Infectious Diseases: A Focus on Air Travel. Trends Parasitol. 2018;34(9):772-83. doi:10.1016/j.pt.2018.07.004.</sup> , <sup>34 ➤
34. 34. Falleiros-Arlant LH, Ayala SEG, Domingues C, Brea J, Colsa-Ranero AD, Falleiros-Arlant LH, et al. Current status of poliomyelitis in Latin America. Revista chilena de infectología [Internet]. 2020;37(6):701-9. [citado 4 de agosto de 2024]. Disponible en: http://www.scielo.cl/scielo.php?script=sci_abstract&pid=S0716-10182020000600701&lng=en&nrm=iso&tlng=en.</sup> . Despite progress, achieving optimal coverage of complete vaccination remains a challenge in the country, posing a potential risk of virus reintroduction as long as global transmission persists <sup>35 ➤
35. 35. Gentile Á, Abate H. A new challenge for the world: the eradication of polio. Arch Argent Pediatr. 2016;114(6):557-62. doi:10.5546/aap.2016.eng.557.</sup> .

Since the PHEIC declaration in 2014, the continued occurrence of cases and environmental detection of the virus in Afghanistan and Pakistan remain significant obstacles to WPV1 eradication, requiring strengthened epidemiological surveillance and immunization campaigns under the goal of eradication by 2026 <sup>36 ➤
36. 36. Al-Kassab-Córdova A, Silva-Perez C, Maguiña JL. Spatial distribution, determinants and trends of full vaccination coverage in children aged 12-59 months in Peru: A subanalysis of the Peruvian Demographic and Health Survey. BMJ Open. 2022;12(11):e05021. doi:10.1136/bmjopen-2021-050211</sup> , <sup>37 ➤
37. 37. WHO. Statement of the Thirty-ninth Meeting of the Polio IHR Emergency Committee. [Internet]. 2024 [citado 18 de agosto de 2024]. Disponible en: https://www.who.int/news/item/13-08-2024-statement-of-the-thirty-ninth-meeting-of-the-polio-ihr-emergency-committee</sup> .

Ebola virus disease (EVD), also known as Ebola hemorrhagic fever, is highly contagious. The first outbreaks occurred in 1976 in Sudan and the Democratic Republic of the Congo, and since then, intermittent outbreaks have been reported in various African countries <sup>38 ➤
38. 38. Letafati A, Salahi Ardekani O, Karami H, Soleimani M. Ebola virus disease: A narrative review. Microb Pathog. 2023;181:106213. doi:10.1016/j.micpath.2023.106213</sup> .Transmission occurs through direct contact with infected individuals, tissues, bodily fluids, or contaminated fomites <sup>39 ➤
39. 39. Jacob ST, Crozier I, Fischer WA, Hewlett A, Kraft CS, Vega MA de L, et al. Ebola virus disease. Nat Rev Dis Primers. 2020;6(1):13. doi:10.1038/s41572-020-0147-3.</sup> .

The West African EVD outbreak (2014–2016) underscored the need to implement effective control and prevention measures to contain its spread. Guinea, Sierra Leone, and Liberia—the most affected countries—lacked sufficient capacity to control the disease, prompting the PHEIC declaration <sup>39-18 ➤
18. 18. Schnirring L. WHO declares Ebola a public health emergency [Internet]. Minneapolis: CIDRAP, University of Minnesota; 2014 Aug 8 [citado 13 de julio de 2024]. Disponible en: https://www.cidrap.umn.edu/ebola/who-declares-ebola-public-health-emergency.</sup> .In 2019, the detection of cases in Uganda stemming from the Democratic Republic of the Congo outbreak demonstrated international spread, leading to a new PHEIC declaration <sup>8 ➤
8. 8. Mullen L, Potter C, Gostin LO, Cicero A, Nuzzo JB. An analysis of International Health Regulations Emergency Committees and Public Health Emergency of International Concern Designations. BMJ Glob Health. 2020;5(6):e002502. doi:10.1136/bmjgh-2020-002502.</sup> . In Peru, these emergencies spurred preparedness for the detection and response to suspected cases, although no autochthonous or imported cases were reported. Despite the end of the PHEIC, recent outbreaks in Uganda highlight the need for constant surveillance and effective containment strategies <sup>40 ➤
40. 40. WHO. Enfermedad por ebolavirus Sudán - Uganda. [Internet]. 2023 [citado 18 de agosto de 2024]. Disponible en: https://www.who.int/es/emergencies/disease-outbreak-news/item/2023-DON433</sup> .

The association of Zika virus with microcephaly and other neurological disorders, documented in Brazil and French Polynesia in 2014, prompted the WHO to declare it a PHEIC in 2016 <sup>21 ➤
21. 21. WHO. WHO statement on the first meeting of the International Health Regulations (2005) (IHR 2005) Emergency Committee on Zika virus and observed increase in neurological disorders and neonatal malformations. [Internet]. 2016 [citado 13 de julio de 2024]. Disponible en: https://www.who.int/news/item/01-02-2016-who-statement-on-the-first-meeting-of-the-international-health-regulations-(2005)-(ihr-2005)-emergency-committee-on-zika-virus-and-observed-increase-in-neurological-disorders-and-neonatal-malformations</sup> . In Peru, epidemiological surveillance of infected pregnant women and their newborns was implemented, though no cases of microcephaly were confirmed. However, the lack of resources during that period may have limited case detection. Currently, the virus continues to circulate in tropical and subtropical regions, including Peru, with the risk of causing epidemics and affecting vulnerable populations, particularly pregnant women <sup>41 ➤
41. 41. Giraldo MI, Gonzalez-Orozco M, Rajsbaum R. Pathogenesis of Zika Virus Infection. Annu Rev Pathol. 2023;18:181-203. doi: 10.1146/annurev-pathmechdis-031521-034739</sup> .

COVID-19 was the first pandemic caused by a coronavirus. SARS-CoV-2, its etiological agent, has shown the ability to infect various mammalian species. Detection of the virus in domestic, wild, and farm animals has led to research on zoonotic transmission (from animals to humans) and reverse zoonosis (from humans to animals), raising the potential for the pandemic to evolve into a panzootic. Monitoring its spread and genomic mutations is crucial to prevent reinfections and develop control strategies based on the One Health approach <sup>43 ➤
43. 43. Johns Hopkins Coronavirus Resource Center. Mortality analyses [Internet]. 2023 [citado el 1 de marzo de 2024]. Disponible en: https://coronavirus.jhu.edu/data/mortality</sup> .During the pandemic, Peru recorded one of the highest cumulative mortality rates in the world <sup>42 ➤
42. 42. Goraichuk IV, Arefiev V, Stegniy BT, Gerilovych AP. Zoonotic and Reverse Zoonotic Transmissibility of SARS-CoV-2. Virus Res. 2021;302:198473. doi:10.1016/j.virusres.2021.198473</sup> , influenced by health, demographic, social, and economic factors. The virus continues to circulate in the country, and surveillance and vaccination efforts among high-risk groups remain ongoing.

Monkeypox (Mpox) was first identified in humans in the Democratic Republic of the Congo in 1970, and cases have since been reported in at least 11 African countries where it is considered endemic. Two clades of the virus have been identified: the West African clade, associated with milder disease, and the Congo Basin clade, associated with greater virulence. Transmission can occur through direct contact, secretions, or respiratory routes. Although most recent cases have been detected in men who have sex with men, there is a risk of spread to the general population <sup>24 ➤
24. 24. Mauldin MR, McCollum AM, Nakazawa YJ, Mandra A, Whitehouse ER, Davidson W, et al. Exportation of Monkeypox Virus From the African Continent. J Infect Dis. 2022;225(8):1367-76. doi:10.1093/infdis/jiaa559.</sup> . Detection of cases in travelers has been key to monitoring the disease and its transmission patterns <sup>24 ➤
24. 24. Mauldin MR, McCollum AM, Nakazawa YJ, Mandra A, Whitehouse ER, Davidson W, et al. Exportation of Monkeypox Virus From the African Continent. J Infect Dis. 2022;225(8):1367-76. doi:10.1093/infdis/jiaa559.</sup> .The two PHEIC declarations by the WHO in 2022 and 2024 reflect that current efforts have not been sufficient to control the disease, with confirmed cases in over 100 countries <sup>25 ➤
25. 25. WHO. 2022-24 Mpox (Monkeypox) Outbreak: Global Trends. [Internet]. 2024 [citado 24 de julio de 2024]. Disponible en: https://worldhealthorg.shinyapps.io/mpx_global/.</sup> .In Peru, since its introduction in 2022, the disease continues to be reported.

The declaration of a PHEIC enables rapid mobilization of resources and international coordination, accelerating the development of vaccines, therapies, and diagnostics under emergency use authorizations. In the current context of globalization and recurring health emergencies, PHEICs have had a significant impact in Peru—especially in terms of morbidity, mortality, and case fatality—posing ongoing challenges for surveillance and response under the IHR-2005 framework <sup>7 ➤
7. 7. Wilder-Smith A, Osman S. Public health emergencies of international concern: a historic overview. J Travel Med. 2020;27(8):taaa227. doi:10.1093/jtm/taaa227.</sup> .

When the WHO declared a PHEIC, Peru’s epidemiological surveillance system issued alerts that prompted the implementation of national surveillance and response actions. Mechanisms were strengthened for early case detection, timely treatment, and death registration. However, in the case of emerging diseases, available resources were insufficient to prevent the introduction and spread of transmission, as observed in the Influenza A(H1N1)-2009 and COVID-19 pandemics. Furthermore, the estimation of the actual number of cases and deaths during a PHEIC is limited by underreporting in each country. While this study analyzes the health impact of PHEICs in Peru, further research is needed to examine their social and economic repercussions.

This study presents several limitations inherent to its design and data sources. First, as a document-based analysis using secondary data from official sources, the quality and completeness of the results depend on the accuracy of the available records. Underreporting of cases and deaths, especially during rapidly spreading events such as Influenza A(H1N1)-2009 and COVID-19, may have affected the true estimation of health impact. Additionally, no adjustments were made for demographic variables or socioeconomic factors, which may influence the interpretation of incidence, mortality, and case fatality indicators. Despite these limitations, this study provides a comprehensive overview of the health impact of PHEICs in Peru and underscores the importance of strengthening epidemiological surveillance and the health system’s response capacity.

Conclusion

In the current context of globalization, accelerated population movement, and the emergence and re-emergence of diseases, PHEICs have had a profound impact on Peru from economic, social, political, and health perspectives. The latter is evident in terms of morbidity, mortality, and case fatality—particularly in the cases of Influenza A(H1N1)-2009, COVID-19, and Mpox. At the same time, these emergencies have provided opportunities to accelerate the development and implementation of core capacities established by the IHR-2005, enabling the country to address all declared PHEICs, which continue to present significant challenges for Peru.