Background: Our purpose was to provide a detailed clinical description, of symptoms and laboratory abnormalities, and temporality in patients with confirmed Zika and dengue infections, and other acute illnesses of unidentified origin (AIUO). Methods/ Principal findings: This was a two-year, multicenter, observational, prospective, cohort study. We collected data from patients meeting the Pan American Health Organization’s modified case-definition criteria for probable Zika infection. We identified Zika, dengue chikungunya by RT-PCR in serum and urine. We compared characteristics between patients with confirmed Zika and dengue infections, Zika and AIUO, and Dengue and AIUO at baseline, Days 3,7,28 and 180 of follow-up. Most episodes (67%) consistent with the PAHO definition of probable Zika could not be confirmed as due to any flavivirus and classified as Acute Illnesses of Unidentified Origin (AIUO). Infections by Zika and dengue accounted for 8.4% and 16% of episodes. Dengue patients presented with fever, generalized non-macular rash, arthralgia, and petechiae more frequently than patients with Zika during the first 10 days of symptoms. Dengue patients presented with more laboratory abnormalities (lower neutrophils, lymphocytosis, thrombocytopenia and abnormal liver function tests), with thrombocytopenia lasting for 28 days. Zika patients had conjunctivitis, photophobia and localized macular rash more frequently than others. Few differences persisted longer than 10 days after symptoms initiation: conjunctivitis in Zika infections, and self-reported rash and petechia in dengue infections. Conclusions: Our study helps characterize the variety and duration of clinical features in patients with Zika, dengue and AIUO. The lack of diagnosis in most patients points to need for better diagnostics to assist clinicians in making specific etiologic diagnoses.

Selenium (Se) is an essential trace element that by its antioxidant properties has been studied to elucidate its participation in the development of obesity and type 2 diabetes. We evaluated the association between cardiometabolic traits and serum Se levels in a sample of adults from southern Mexico. In 96 nondiabetic individuals, anthropometric data and clinical biochemistry measurements were analyzed. Serum total Se levels were measured with inductively coupled plasma mass spectrometry (ICP-MS). Serum Se level in the whole sample was 10.309 ± 3.031 μg mL⁻¹ and no difference between the women and men was observed (p = 0.09). Additionally, fasting plasma glucose (FPG) was significantly associated with serum Se level (β = −0.07 ± 0.03, p = 0.02, analysis adjusted for age, sex and BMI). Furthermore, sex shows significant interaction with FPG on the serum Se levels (p = 0.01). A follow-up analysis revealed the particular association between FPG and Se levels in women (β = −0.10 ± 0.04, p = 0.01). In conclusion, our data evidenced a women-specific association between FPG and serum Se levels in a sample of adults from southern Mexico.

Emerging and re-emerging vector-borne infections are a global public health threat. In endemic regions, fever is the main reason for medical attention, and the etiological agent of such fever is not usually identified. In this study, non-specific febrile pathogens were molecularly characterized in serum samples from 253 patients suspected of arbovirus infection. The samples were collected in the southern border region of Mexico from April to June 2015, and February to March 2016. ZIKV, CHIKV, DENV, leptospirosis, and rickettsiosis were detected by qPCR and nested PCR to identify flavivirus and alphavirus genera. The results indicated that 71.93% of the samples were positive for CHIKV, 0.79% for ZIKV, and 0.39% for DENV, with the number positive for CHIKV increasing to 76.67% and those positive for ZIKV increasing to 15.41% under the nested PCR technique. Leptospira Kmetyi was identified for the first time in Mexico, with a prevalence of 3.16%. This is the first report of ZIKV in Mexico, as well the first detection of the virus in early 2015. In conclusion, the etiological agent of fever was determined in 94% of the analyzed samples.

Between 2 and 8.5% of patients who recover from COVID-19 do not develop antibodies, and the durability of IgG antibodies is under scrutiny. Therefore, the presence and persistence of IgM and IgG antibodies were evaluated in a group of patients diagnosed with SARS-CoV-2 from May to August 2020. Out of 2199 suspected COVID-19 cases, 1264 were confirmed for SARS-CoV-2 by rRT-PCR; 328 consented to participate in the study, with 220 participants followed for 9 months, including 124 men (56%) and 96 women (44%). The primary symptoms were headache, dry cough, and fever. IgG antibodies developed in 95% of patients within 4 weeks post-diagnosis, and a second evaluation at 9 months showed that 72.7% still had detectable IgG antibodies. The presence of IgM in one individual (0.45%) suggested the possibility of reinfection.

To develop and validate a quantitative PCR Multiplex Array assay for the detection of viral sequences in breast cancer (BC) tissue, and to assess its potential utility as a molecular research and diagnostic tool. A total of 172 formalin-fixed paraffin-embedded (FFPE) biopsy samples from patients with a histological diagnosis of BC, and 10 non-neoplastic breast tissue samples were collected at the High Specialty Regional Hospital "Ciudad Salud" (HRAECS). The study was approved by the Institutional Research and Ethics Committees. Samples were analyzed using a qPCR Multiplex Array assay. gBlocks Gene Fragments at 10 ng/µL were used as positive controls for each target virus. Assay validation demonstrated high specificity, linearity (R² > 0.98), amplification efficiencies within the 90-110% range, and reproducibility (CV < 5%), confirming the reliability of this method for viral detection in clinical tissue samples. Viral sequences were detected in 30% (51/172) of cases for HPV, 24% (41/172) for MMTV, and 0.6% (1/172) for EBV. Sanger sequencing confirmed 100% sequence identity with GenBank reference sequences in all positive samples. A qPCR Multiplex Array assay targeting 21 viral sequences was developed and validated, providing a reliable tool for the detection of cancer-associated viral sequences in BC tissue. Detection of viral sequences confirms their presence in tumor tissue but does not establish causality with carcinogenesis. Future studies integrating transcriptomic, functional, and clinical analyses are needed to clarify the role of these viruses in BC, including associations with clinicopathological features and potential therapeutic implications.

Como resultado de su ciclo evolutivo, el virus SARS-CoV-2, agente causal de COVID-19, ha sufrido mutaciones genéticas durante el transcurso de la pandemia, originando diferentes variantes. Las variantes que presentan un potencial de riesgo para la salud pública son denominadas como Variantes de Preocupación (VOC) por la Organización Mundial de la Salud (OMS). Dentro de esta clasificación se encuentra la variante Delta (B.1.617.2) debido a su capacidad de escapar de la inmunidad, ya sea de manera natural o inducida por las vacunas, lo que puede generar reinfecciones, mayor transmisibilidad y gravedad. Esta variante fue identificada por primera vez en octubre de 2020 en India. En México, se reconoció como variante circulante el 18 de abril de 2021, mientras que en Chiapas fue el 16 de julio del mismo año. Con base en ello, se realizó la vigilancia de las variantes epidemiológicamente relevantes Alfa, Beta, Gamma y Delta en un grupo de 117 pacientes diagnosticados con SARS-CoV-2 que acudieron durante los meses de enero a julio de 2021 a un laboratorio privado con reconocimiento del InDRE en Tapachula, Chiapas. La identificación de variantes y su confirmación se realizó en el Laboratorio de Investigación en Ciencias Biomédicas de la Facultad de Medicina Humana, Campus IV, UNACH. De los 117 pacientes, con una edad promedio de 46 ± 15 años, 62% (n=72) fueron hombres y 38% (n=45) mujeres. Se encontró que la variante Delta ha estado presente como variante circulante en nuestra población desde enero de 2021, observando un incremento importante en el mes de mayo. En el 73% (87/117) de los casos, se encontró la variante Delta como monoinfección y coinfección, mientras que las variantes silvestre, Alfa, Beta y Gamma se identificaron en menor proporción.