BACKGROUND:Peru recorded one of the world's highest COVID-19 mortality rates, with nearly 4.5 million reported cases and 220,000 deaths by March 2024. Understanding the emergence and spread of SARS-CoV-2 variants in this context is key to informing effective public health responses. This study describes the genomic diversity, transmission dynamics, and geographic spread of SARS-CoV-2 in Peru from 2020 to 2024. METHODS:We analyzed nearly 50,000 high-quality public SARS-CoV-2 genome sequences collected nationwide between March 2020 and March 2024. Phylogeographic and mutational analyses were performed to identify variant lineages, trace their origins, and map viral movements within and beyond Peru. RESULTS:We show that Peru's epidemic waves were shaped by the emergence of locally evolved variants, including Lambda (C.37), Gamma (P.1.12), and Omicron (XBB.2.6 and DJ.1) sub-lineages. The city of Lima acted as the primary hub for inter-regional spread, accounting for 47.3% of inferred viral movements to other departments, notably Ancash, Cusco, and Piura. Peru was the source of various lineages that spread internationally, primarily to Chile, the USA, and Europe. Mutational analysis highlighted critical mutations in the spike protein, including L452Q and F490S in Lambda, associated with immune evasion and increased transmissibility. CONCLUSIONS:This work demonstrates the capacity of genomic surveillance in Peru to detect and track emerging SARS-CoV-2 variants, providing insights into regional and global transmission dynamics in a high-transmission, middle-income country setting. Sustained, cost-effective genomic monitoring, combined with strengthened bioinformatics and laboratory capacity, is essential for pandemic preparedness in resource-limited settings.

Objective To characterize the molecular epidemiology and genomic diversity of hepatitis B virus (HBV) and hepatitis delta virus (HDV) in Peru using next-generation sequencing (NGS). Materials and Methods A cross-sectional observational study was conducted using 209 serum/plasma samples from various regions of Peru, stored at the National Institute of Health. Detection of HBV and HDV was performed by PCR and RT-PCR, respectively. Nucleic acids were purified and quantified for library preparation and sequencing using the Illumina platform. Sequencing reads were aligned to reference genomes to determine genotypes, subgenotypes, and clinically relevant mutations. Geneious Prime was used for assembly and phylogenetic analysis, and STATA v.14.0 for statistical analysis. Results HBV genotype F was the most prevalent (96.1%), with subgenotype F1b being predominant, followed by genotypes H, G, and C. Mutations associated with virulence and immune escape were identified, particularly A1762T/G1764A (66.7%) and A1762T/G1764A + G1896A (45.7%). All HDV sequences corresponded to genotype 3 (HDV-3), which was detected in six regions of the country. Conclusions The findings confirm the predominant circulation of HBV genotype F and HDV genotype 3 in Peru, with genotypic diversity that may influence clinical outcomes, viral load, and response to treatment. Sustained molecular surveillance programs are recommended in endemic areas to guide control, treatment, and prevention strategies. ### Competing Interest Statement The authors have declared no competing interest.

OBJECTIVES:Artemisinin-resistant Plasmodium falciparum challenges the effectiveness of all artemisinin-based combination therapies. METHODS:We conducted a clinical study in Peru, Kenya, and Thailand between June 2013 and November 2015 in subjects treated with three standard doses of artesunate followed by two doses of mefloquine. The primary endpoint was parasite clearance half-life (PC1/2) during the 72-hour period of treatment. Secondary endpoints included clinical outcome at 42 days, detection of kelch13 (K13) mutations, pharmacokinetics, and pharmacodynamics. RESULTS:The mean PC1/2 was higher in the Thai (4.1 hours) than Peruvian (2 hours) or Kenyan cohorts (2.2 hours) (P <0.0001). Higher PC1/2 was partially explained by K13 mutations in 13 (28%) of 46 Thai subjects, including World Health Organization (WHO) validated and candidate mutations. Twelve (26%) Thai cohort subjects had PC1/2 ≥5 hours with parasites from nine subjects carrying K13 mutations. There was an overall 42-day cure rate of 100% across all subjects. CONCLUSIONS:This is the first concurrent evaluation of artemisinin resistance across three continents. The presence of 11% Thai subjects who satisfied WHO criteria for drug resistance establishes this area as endemic. Longer PC1/2 found in wild-type and candidate K13 mutant infections within the Thai cohort require further investigation to identify alternative mechanisms of resistance.

Introduction. Mobile applications represent a promising alternative for providing support in the management of Dengue patients. However, the usability of these tools in Peru is unknown. Objectives. To evaluate the usability and usage recommendations of the Dengue ONQOY application in managing Dengue patients in rural areas of Peru. Methods. A qualitative study was conducted, which included semi-structured interviews with 8 experts in Dengue management. Data were coded using Atlas. Ti software. Three categories were assessed: (1) informative usability (2) design usability, and (3) recommendations for improvement. Results. Three key aspects were highlighted. (1) The application is perceived as valuable for first- level doctors in peripheral areas with limited Dengue experience due to its personalized approachand academic value. (2) Its ease of use and practicality were emphasized, although connectivity limitations in some areas were noted. (3) Recommendations for improvement included the inclusion of differential diagnoses, additional risk factors, updated references, hydration guidelines, and medication dosages. Conclusions. Dengue ONQOY is considered highly usable by doctors treating Dengue cases at the primary care level in Peru. Despite connectivity limitations and potential design improvements, its development and implementation offer a promising alternative for managing Dengue patients in the country in this field.

Objetivo. Estimar los costos incurridos en el control del Aedes aegypti en la región Loreto, en los años 2017 y 2018. Materiales y métodos. Se realizó una evaluación económica retrospectiva parcial de los costos del control del Aedes aegypti de la Dirección Regional de Salud Loreto, durante la ejecución del Plan Regional de Vigilancia y Control de Aedes aegypti. Se revisó documentación como planes, informes de intervenciones y planillas de pago y se realizaron entrevistas al personal profesional implicado en el control vectorial, sobre los costos de las intervenciones de control. Resultados. Se halló, que los costos incurridos en el control del vector del dengue en la Región Loreto en los dos años estudiados ascienden a: 3,807,858 PEN y 4,066,380 PEN durante el 2017 y 2018, respectivamente (1´175,264 USD y 1´1210,232 USD al tipo de cambio del 2017 y 2018). Sin embargo, el efecto de las actividades de control es de corta duración. Conclusiones. El alto costo que implica el control vectorial con los métodos usados actualmente y la corta duración de su efecto lo hace insostenible. Se deben realizar estudios para hallar otros métodos más eficientes para el control del dengue.

During early 2021, Peru had the highest COVID-19-associated per-capita mortality rate. Socioeconomic inequality, insufficiently prepared healthcare, and surveillance systems are factors explaining the mortality rate, which can be severely worsened by early undetected SARS-CoV-2 circulation. We tested 1,441 individuals with fever sampled during August 2019-May 2021, several months before the first SARS-CoV-2 seroprevalence study available so far in Lima, Peru, for SARS-CoV-2-specific antibodies. The testing algorithm included a chemiluminescence immunoassay and surrogate virus neutralization test. Early positive samples (N = 24) from January-March 2020 were further tested using a plaque-reduction neutralization test (PRNT) and avidity test against the SARS-CoV-2 spike and nucleoprotein. None of the early samples were PRNT-confirmed, in contrast to 81.8% (18/22) of a subsample from April 2020 onward (Fisher exact test; P <0.0001). Therefore, we excluded non-PRNT-confirmed samples from subsequent analyses. The SARS-CoV-2 antibody detection rate was 0.9% in mid-April 2020 (1/104; 95% CI: 0.1-5.8%), suggesting viral circulation in early-middle March 2020, consistent with the first molecular detection of SARS-CoV-2 in Peru on March 2020. Mean avidity increase of 62-77% to 81-94% from all PRNT-confirmed SARS-CoV-2-positive samples during early 2020 were consistent with onset of SARS-CoV-2 circulation during late February/March 2020. Early circulation was also confirmed in a susceptible, exposed, infected, and recovered mathematical model that calculated an effective reproduction number >1 during February-March 2020. Early introduction of SARS-CoV-2 thus contributed to the high COVID-19 mortality rate in Peru. Emphasizing the role of diagnostic confirmation in understanding the pandemic's trajectory, this study highlights the importance of early detection and accurate testing in managing infectious disease outbreaks.

OBJECTIVE.:Motivation for the study. Dengue prevention and control is based on the control of its vector. This study was conducted because of the need to know the costs associated with Aedes aegypti control in a region that carries out planned vector control activities. Main findings. The costs incurred in dengue vector control in the Loreto region in 2017 and 2018 amounted to PEN 4,066,380.25 and PEN 3,807,858.73, respectively. Implications. Knowing the cost of vector control activities will allow us to better plan these activities and have a basis for cost-effectiveness studies with other methods of prevention and control of dengue. To estimate the costs incurred in the control of Aedes aegypti in the Loreto region, during the years 2017 and 2018. MATERIALS AND METHODS.:We conducted a partial retrospective economic evaluation of the costs of Aedes aegypti control of the Regional Health Directorate Loreto, during the implementation of the Regional Plan for Surveillance and Control of Aedes aegypti. Documentation such as plans, intervention reports and payment slips were reviewed, and interviews were conducted with professional personnel involved in vector control, on the costs of control interventions. RESULTS.:We found that the costs incurred in dengue vector control in the Loreto Region in the two years were: PEN 3,807,858 and PEN 4,066,380 during 2017 and 2018, respectively (USD 1,175,264 and USD 1,1210,232 at the 2017 and 2018 exchange rate). However, the effect of control activities is short-lived. CONCLUSIONS.:The high cost involved in vector control with the methods currently used and the short duration of its effect make it unsustainable. Studies should be conducted in order to find other more efficient methods for dengue control.

La aspergilosis invasiva presenta alta mortalidad en pacientes con enfermedades crónicas e inmunocomprometidos. Aspergillus fumigatus sensu stricto (AFSS) es el principal agente etiológico y su tipificación requiere de métodos moleculares. La incidencia incrementada de AI resistentes a los antifúngicos demanda un diagnóstico certero y oportuno. Métodos. Se estudiaron 20 cepas de la micoteca del Instituto de Medicina Tropical – Universidad Nacional Mayor de San Marcos, aisladas de muestras respiratorias e identificadas como Aspergillus fumigatus sensu lato mediante el estudio macroscópico y microscópico. Las cepas fueron referidas a la Universidad Nacional del Litoral para su tipificación mediante una PCR screening para AFSS basada en secuencias del gen CYP51A y el estudio de sensibilidad antifúngica para voriconazol (VOR), itraconazol (ITC), posaconazol (POS), isavuconazol (ISA), anidulafungina (ANF), caspofungina (CSF) y anfotericina B (AMB) obteniendo la concentración inhibitoria mínima (CIM) mediante el protocolo de CLSI M38M51S-Ed3. Resultados. Las 20 cepas fueron identificadas como AFSS. Ninguna de las cepas tuvo una CIM por encima del punto de corte clínico (VOR), ni epidemiológico (ITC, ISA, AMB y CSF). POS fue la droga más potente frente a la colección de cepas evaluadas (media geométrica (GM) de CIM de 0,042 µg/ml). Conclusiones. Todos los aislamientos fueron tipificados como AFSS sensibles a los azoles según los puntos de corte clínico, posaconazol tuvo la mayor actividad antifúngica. Nuestros hallazgos aportan a incrementar la escasa información sobre la etiología y sensibilidad a los antifúngicos de uso clínico de las aspergilosis invasiva en nuestro país.

El síndrome de Guillain Barré es una enfermedad derivada del compromiso en las neuronas del sistema nervioso periférico por una respuesta descontrolada del sistema inmune que conduce daño axonal y/o desmielinización. El objetivo de este reporte fue describir los 10 primeros casos sospechosos de Síndrome de Guillain Barré en Piura. Se logró identificar la presencia de Campylobacter jejuni en las muestras de heces del 80% de los pacientes reportados. Es muy importante reconocer rápida y oportunamente al paciente con diagnóstico sospechoso de Guillain Barré, y realizar los estudios necesarios en un brote para identificar los agentes desencadenantes del cuadro.