Background/Objectives: The coronavirus disease 2019 (COVID-19) pandemic profoundly disrupted global respiratory virus circulation, with sharp declines during 2020–2021, followed by a resurgence after the relaxation of public health measures. In South America, post-pandemic respiratory virus dynamics remain insufficiently characterized, particularly in ecologically diverse regions. Arequipa, a high-altitude city in southern Peru, has unique environmental conditions, including marked seasonal temperature variability, that may influence viral transmission. Methods: We performed a cross-sectional analysis of 21,784 nasopharyngeal swabs collected from symptomatic patients at four major hospitals between June 2021 and September 2023. All samples were tested for SARS-CoV-2 by RT-qPCR. Because routine screening for other respiratory viruses was implemented only in SARS-CoV-2-negative cases during the study period, a subset of SARS-CoV-2-negative samples was subsequently analyzed for influenza A virus (IAV), influenza B virus (IBV), and respiratory syncytial virus (RSV) using VIASURE assays. Viral circulation patterns were evaluated by year, month, and epidemiological week. Meteorological data were obtained from the SENAMHI–La Pampilla station. Logistic regression models were used to assess epidemiological and climatic predictors of viral detection. Results: SARS-CoV-2 positivity declined from 20.0% in 2021 to 8.8% in 2023. Conversely, detection of other respiratory viruses among SARS-CoV-2-negative samples increased from 0.8% in 2021 to 29.0% in 2023 (p < 0.01). Temporal increases in detection were observed during 2022–2023, particularly for IAV and RSV. In exploratory analyses, calendar year and relative humidity were associated with IAV and RSV detection, while age and temperature variables were associated with IBV. Conclusions: Climatic and demographic variables were associated with changes in viral detection for IAV, IBV, and RSV during the post-pandemic transition period in Arequipa. These findings describe patterns of viral detection within SARS-CoV-2-negative symptomatic patients and should be interpreted as surveillance-based observations rather than population-level estimates. Strengthened integrated epidemiological and genomic surveillance will be essential for vaccine planning and outbreak preparedness in the post-pandemic era.

The influence of Bacillus subtilis (Solution A) and Paenibacillus polymyxa (Solution B) bacteria on the properties of conventional concrete with a design compressive strength of f′c = 210 kg/cm² and on the repair of microcracks and fissures was evaluated. Yura Type IP and Frontera Type IP cements were used, together with aggregates from the Chiguata and La Poderosa quarries (Arequipa, Peru). Two mix design methods were applied: ACI 211 and the fineness modulus of the combined aggregates. For microcrack repair, injections of Solutions A and B were applied, followed by either water curing or curing in the corresponding bacterial solution. For water replacement, both solutions were used at concentrations of 10%, 15%, and 20%. Compressive strengths were measured at 7, 14, 21, and 28 days. The results indicate that bacterial incorporation, together with reductions in the effective water-to-cement ratio associated with bacterial solution replacement, was associated with improvements in compressive strength and microcrack repair through mechanisms consistent with calcium carbonate (CaCO₃) precipitation. For the injection group, a maximum strength of 196.09 kg/cm² was obtained. For the water replacement group, a maximum strength of 335.71 kg/cm² was reached, representing a 59.9% increase over the standard design. The P. polymyxa solution consistently outperformed B. subtilis across all groups and concentrations evaluated. These findings suggest that bacterial solutions—particularly P. polymyxa—may represent a promising complementary strategy to improve concrete performance and durability under the evaluated experimental conditions.

Background Human cytomegalovirus (HCMV) infection causes life-threatening complications in transplant recipients. Despite a seroprevalence exceeding 90% in Peru, the influence of HLA diversity on HCMV immune recognition remains unexplored in the South American region. We aimed to characterize the HLA allele distribution in a Peruvian cohort and evaluate its impact on the predicted HCMV antigen-presentation landscape. Methods HLA genotyping (loci A, B, C, DRB1, DQA1, DQB1) was performed in 562 kidney transplant candidates and related donors. Common allele groups (AF5%) were assigned 4-digit resolution proxies based on local prevalence. Linear T-cell epitopes from the immunodominant antigens 65 kDa phosphoprotein (pp65), Immediate early protein 1 (IE1), and Envelope glycoprotein B (gB) were predicted using high-performance algorithms. Allelic capacity to strongly bind antigenic peptides was quantified using the Predicted Strong Binder Density (PSBD). Results We identified 16 HLA-I and 10 HLA-II common allele groups; 92% of their 4-digit proxies are widely distributed in SAM, while C*15:12 emerged as a potentially endemic variant in Peru. Screening yielded 954 HLA-I candidate epitopes, including 169 that correspond to previously reported IEDB epitopes with potential for immunotherapy. PSBD analysis revealed distinct predicted antigen-presentation profiles across the common HLA variants identified. Conclusion Our findings provide updated Peruvian HLA data and define regional HCMV antigen-presentation profiles based on predicted MHC-peptide binding affinity (PSBD). Further experimental validation of these high-confidence candidate epitopes and HLA-HCMV association studies will be necessary to determine their immunogenicity and potential utility for immune monitoring and future immunotherapeutic applications across South American populations.

Background Human cytomegalovirus (HCMV) infection causes life-threatening complications in transplant recipients. Despite a seroprevalence exceeding 90% in Peru, the influence of HLA diversity on HCMV immune recognition remains unexplored in the South American region. We aimed to characterize the HLA allele distribution in a Peruvian cohort and evaluate its impact on the predicted HCMV antigen-presentation landscape. Methods HLA genotyping (loci A, B, C, DRB1, DQA1, DQB1) was performed in 562 kidney transplant candidates and related donors. Common allele groups (AF5%) were assigned 4-digit resolution proxies based on local prevalence. Linear T-cell epitopes from the immunodominant antigens 65 kDa phosphoprotein (pp65), Immediate early protein 1 (IE1), and Envelope glycoprotein B (gB) were predicted using high-performance algorithms. Allelic capacity to strongly bind antigenic peptides was quantified using the Predicted Strong Binder Density (PSBD). Results We identified 16 HLA-I and 10 HLA-II common allele groups; 92% of their 4-digit proxies are widely distributed in SAM, while C*15:12 emerged as a potentially endemic variant in Peru. Screening yielded 954 HLA-I candidate epitopes, including 169 that correspond to previously reported IEDB epitopes with potential for immunotherapy. PSBD analysis revealed distinct predicted antigen-presentation profiles across the common HLA variants identified. Conclusion Our findings provide updated Peruvian HLA data and define regional HCMV antigen-presentation profiles based on predicted MHC-peptide binding affinity (PSBD). Further experimental validation of these high-confidence candidate epitopes and HLA-HCMV association studies will be necessary to determine their immunogenicity and potential utility for immune monitoring and future immunotherapeutic applications across South American populations.

Background: Human cytomegalovirus (HCMV) infection causes life-threatening complications in transplant recipients. Despite a seroprevalence exceeding 90% in Peru, the influence of HLA diversity on HCMV immune recognition remains unexplored in the South American region. We aimed to characterize the HLA allele distribution in a Peruvian cohort and evaluate its impact on the predicted HCMV antigen-presentation landscape. Methods: HLA genotyping (loci A, B, C, DRB1, DQA1, DQB1) was performed in 562 kidney transplant candidates and related donors. Common allele groups (AF5%) were assigned 4-digit resolution proxies based on local prevalence. Linear T-cell epitopes from the immunodominant antigens 65 kDa phosphoprotein (pp65), Immediate early protein 1 (IE1), and Envelope glycoprotein B (gB) were predicted using high-performance algorithms. Allelic capacity to strongly bind antigenic peptides was quantified using the Predicted Strong Binder Density (PSBD). Results: We identified 16 HLA-I and 10 HLA-II common allele groups; 92% of their 4-digit proxies are widely distributed in SAM, while C*15:12 emerged as a potentially endemic variant in Peru. Screening yielded 954 HLA-I candidate epitopes, including 169 that correspond to previously reported IEDB epitopes with potential for immunotherapy. PSBD analysis revealed distinct predicted antigen-presentation profiles across the common HLA variants identified. Conclusion: Our findings provide updated Peruvian HLA data and define regional HCMV antigen-presentation profiles based on predicted MHC-peptide binding affinity (PSBD). Further experimental validation of these high-confidence candidate epitopes and HLA-HCMV association studies will be necessary to determine their immunogenicity and potential utility for immune monitoring and future immunotherapeutic applications across South American populations.

Background Human cytomegalovirus (HCMV) infection causes life-threatening complications in transplant recipients. Despite a seroprevalence exceeding 90% in Peru, the influence of HLA diversity on HCMV immune recognition remains unexplored in the South American region. We aimed to characterize the HLA allele distribution in a Peruvian cohort and evaluate its impact on the predicted HCMV antigen-presentation landscape. Methods HLA genotyping (loci A, B, C, DRB1, DQA1, DQB1) was performed in 562 kidney transplant candidates and related donors. Common allele groups (AF5%) were assigned 4-digit resolution proxies based on local prevalence. Linear T-cell epitopes from the immunodominant antigens 65 kDa phosphoprotein (pp65), Immediate early protein 1 (IE1), and Envelope glycoprotein B (gB) were predicted using high-performance algorithms. Allelic capacity to strongly bind antigenic peptides was quantified using the Predicted Strong Binder Density (PSBD). Results We identified 16 HLA-I and 10 HLA-II common allele groups; 92% of their 4-digit proxies are widely distributed in SAM, while C*15:12 emerged as a potentially endemic variant in Peru. Screening yielded 954 HLA-I candidate epitopes, including 169 that correspond to previously reported IEDB epitopes with potential for immunotherapy. PSBD analysis revealed distinct predicted antigen-presentation profiles across the common HLA variants identified. Conclusion Our findings provide updated Peruvian HLA data and define regional HCMV antigen-presentation profiles based on predicted MHC-peptide binding affinity (PSBD). Further experimental validation of these high-confidence candidate epitopes and HLA-HCMV association studies will be necessary to determine their immunogenicity and potential utility for immune monitoring and future immunotherapeutic applications across South American populations.