Humoral Immune Response Induced by the BBIBP-CorV Vaccine (Sinopharm) in Healthcare Workers: A Cohort Study.

Insufficient data have been reported about the effect of the inactivated SARS-CoV-2 vaccine (BBIBP-CorV) on the humoral response through time in healthcare workers (HCW). This retrospective cohort studied the information of 252 HCW from a private laboratory, comparing the antibody-mediated response provoked by BBIBP-CorV between HCW previously infected with SARS-CoV-2 (PI) and not previously infected (NPI), employing the Elecsys® anti-SARS-CoV-2 S and the cPass™ SARS-CoV-2 Neutralization Antibody Detection kit at intervals of 21, 90, and 180 days after vaccination. The presence of neutralizing antibodies in HCW 21 days after full vaccination was 100% in PI and 91.60% in NPI. We observed a progressive decrease in antibody levels over time in both groups. Comparing HCW PI with NPI, PI had a 10.9, 14.3, and 8.6-fold higher antibody titer with the Elecsys® anti-SARS-CoV-2 S at 21 (p < 0.001), 90 (p< 0.001) and 180 days (p <0.001) respectively, compared to NPI. Using the percent of signal inhibition (PSI) of the antibody neutralization cPass™, HCW PI showed a level of 1.3, 2.0, and 3.1 times more antibodies, at 21 (p <0.001), 90 (p <0.001), and 180 days (p <0.001) respectively, compared to NPI. We determined a progressive decrease in humoral immunity over time, particularly higher in those NPI.

Neutralizing Antibodies as Predictors of Vaccine Breakthrough Infection in Healthcare Workers Vaccinated with or without a Heterologous Booster Dose: A Cohort Study during the Third COVID-19 Wave in Peru.

We evaluated neutralizing antibody (NAbs) levels as a protective factor against vaccine breakthrough infection (VBI) in healthcare workers (HCWs) during the third COVID-19 wave in Peru. This retrospective cohort study employed the information from a private laboratory in Lima (Peru) of HCW who received only two BBIBP-CorV vaccines or (additionally) a heterologous booster with BNT162b2. We evaluated the association between the VBI and the levels of NAbs at 21, 90, 180, and 210 days after the BBIBP-CorV second dose. NAbs were calculated with the cPass™ SARS-CoV-2 Neutralization Antibody Detection kit (surrogate virus neutralization test (sVNT)) and the Elecsys® anti-SARS-CoV-2 S Test. Of the 435 HCW evaluated, 31.72% had an infection previous to vaccination, 68.28% received a booster dose, and 23.21% had a VBI during the third wave. The variables associated with a lower risk of VBI were male sex (aRR: 0.43) and those who had (180 days after BBIBP-CorV inoculation) NAbs levels ≥ 60% (aRR: 0.58) and ≥90% (aRR: 0.59) on cPass™, and ≥500 with Elecsys® (aRR: 0.58). HCW whose NAbs persisted at higher levels six months after the BBIBP-CorV showed a lower risk of suffering from a VBI during the third COVID-19 wave.

Determination of PaO2/FiO2 after 24 h of invasive mechanical ventilation and ΔPaO2/FiO2 at 24 h as predictors of survival in patients diagnosed with ARDS due to COVID-19.

Introduction: Acute respiratory distress syndrome (ARDS) due to Coronavirus Disease 2019 (COVID-19) causes high mortality. The objective of this study is to determine whether the arterial pressure of oxygen/inspiratory fraction of oxygen (PaO2/FiO2) 24 h after invasive mechanical ventilation (IMV) and the difference between PaO2/FiO2 at 24 h after IMV and PaO2/FiO2 before admission to IMV (ΔPaO2/FiO2 24 h) are predictors of survival in patients with ARDS due to COVID-19. Methods: A retrospective cohort study was conducted that included patients with ARDS due to COVID-19 in IMV admitted to the intensive care unit (ICU) of a hospital in southern Peru from April 2020 to April 2021. The ROC curves and the Youden index were used to establish the cut-off point for PaO2/FiO2 at 24 h of IMV and ΔPaO2/FiO2 at 24 h associated with mortality. The association with mortality was determined by Cox regression, calculating the crude (cHR) and adjusted (aHR) risk ratios, with their respective 95% confidence intervals (95% CI). Results: Two hundred patients were analyzed. The average age was 54.29 years, 79% were men, and 25.5% (n = 51) died. The cut-off point calculated for PaO2/FiO2 24 h after IMV and ΔPaO2/FiO2 24 h was 222.5 and 109.5, respectively. Those participants with a value below the cut-off point of ΔPaO2/FiO2 24 h and PaO2/FiO2 24 h after IMV had higher mortality, aHR = 3.32 (CI 95% [1.82-6.07]) and aHR = 2.87 (CI 95% [1.48-5.57]) respectively. Conclusion: PaO2/FiO2 24 h after IMV and ΔPaO2/FiO2 24 h in patients diagnosed with ARDS due to COVID-19 on IMV were associated with higher hospital mortality. These findings are helpful to identify those patients with a higher risk of dying on admission to the ICU.

Clinical Characteristics Associated with Detected Respiratory Microorganism Employing Multiplex Nested PCR in Patients with Presumptive COVID-19 but Negative Molecular Results in Lima, Peru.

The COVID-19 pandemic circumstances have varied the pathogens related to acute respiratory infections (ARI), and most specialists have ignored them due to SARS-CoV-2's similar symptomatology. We identify respiratory pathogens with multiplex PCR in samples with presumptive SARS-CoV-2 but negative RT-qPCR results. We performed a retrospective transversal study employing clinical data and nasopharyngeal swab samples from patients with suspected clinical SARS-CoV-2 infection and a negative PCR result in a private laboratory in Lima, Peru. The samples were analyzed using the FilmArray™ respiratory panel. Of 342 samples, we detected at least one pathogen in 50% of the samples. The main ones were rhinovirus (54.38%), influenza A(H3N2) (22.80%), and respiratory syncytial virus (RSV) (14.04%). The clinical characteristics were sore throat (70.18%), cough (58.48%), nasal congestion (56.43%), and fever (40.06%). Only 41.46% and 48.78% of patients with influenza met the definition of influenza-like illness (ILI) by the World Health Organization (WHO) (characterized by cough and fever) and the Centers for Disease Control and Prevention (CDC) (characterized by fever and cough and sore throat), respectively. A higher prevalence of influenza was associated with ILI by WHO (aPR: 2.331) and ILI by CDC (aPR: 1.892), which was not observed with other respiratory viruses. The clinical characteristic associated with the increased prevalence of rhinovirus was nasal congestion (aPR: 1.84). For patients with ARI and negative PCR results, the leading respiratory pathogens detected were rhinovirus, influenza, and RSV. Less than half of patients with influenza presented ILI, although its presence was specific to the disease.

Sleep Disorders and Their Associated Factors during the COVID-19 Pandemic: Data from Peruvian Medical Students.

Background and objectives: Sleep disorders are a common public health problem among college students. The objective of this study was to evaluate sleep quality and its associated factors in medical students during the COVID-19 pandemic. Materials and Methods: Cross-sectional analytical study-we conducted a secondary analysis of the survey "Nomophobia in medical students in Peru" database between 2020 and 2021. Sleep disturbances were assessed using the Pittsburgh Sleep Quality Index (PSQI). To evaluate associated factors, crude and adjusted prevalence ratios (aPR) and their 95% confidence intervals (95% CI) were calculated. Results: We analyzed data from 3139 participants from 18 cities in Peru (61.1% were women, median age: 22 years). 43.4% had a quality of sleep that could require medical attention; the PSQI dimension with the highest score was daytime dysfunction. The poor sleep quality was associated with symptoms of anxiety (aPR: 1.48; 95% CI: 1.27-1.72), depression (aPR: 2.03; 1.72-2.39), or nomophobia (aPR: 1.28; 1.09-1.51). Conclusions: Sleep disorders were a common problem among Peruvian medical students and were associated with anxiety, depression, or nomophobia symptoms.

Fear of Death in Medical Students from a Peruvian University during the COVID-19 Pandemic.

Due to close contact with death, medical students may question their own and their patients' dying process, especially with the impact of the COVID-19 pandemic on the increase in deaths. This situation provokes fear and negative attitudes towards dealing with patients and their environment. This study aimed to assess the level of fear of death and associated factors in medical students at a Peruvian university. A cross-sectional analytical study was conducted during March 2021 in human medicine students from the first to the seventh year. A validated survey including the Collet-Lester fear-of-death scale was applied. Factors associated with the fear-of-death score were evaluated by calculating linear regression coefficients (ß). A total of 284 students were included. The median age was 22 years, and 58.1% were female. The mean Collet-Lester scale score was 2.79, and it was higher in the dimensions related to the death of others. Adjusted analysis showed that the score on this scale was lower in students aged 24-40 years compared to 17-21 years (ß: -0.25; 95% CI: -0.46 to -0.04) and those who had no religious beliefs (ß: -0.29; 95% CI: -0.53 to -0.04). In conclusion, fear of death was lower than reported in other investigations despite the COVID-19 situation, being much lower among older students and those without religious beliefs.

Evaluation of the Humoral Immune Response of a Heterologous Vaccination between BBIBP-CorV and BNT162b2 with a Temporal Separation of 7 Months, in Peruvian Healthcare Workers with and without a History of SARS-CoV-2 Infection.

Information on the effects of a heterologous booster in adult patients first vaccinated with the BBIBP-CorV vaccine is limited. This prospective cohort study evaluated the humoral response of 152 healthcare workers (HCWs) from a private laboratory in Lima (Peru) before and after receiving the BNT162b2 vaccine, with a seven-month interval since the BBIBP-CorV doses. We employed the Elecsys® anti-SARS-CoV-2 S and the cPass™ SARS-CoV-2 Neutralization Antibody (NAbs) assays to evaluate anti-S-RBD IgG and NAbs, respectively. Of the 152 HCWs, 79 (51.98%) were previously infected (PI) with SARS-CoV-2 and 73 (48.02%) were not previously infected (NPI). The proportion of HCWs with positive NAbs, seven months after the BBIBP-CorV immunization, was 49.31% in NPI and 92.40% in PI. After the booster, this ratio increased to 100% in both groups. The anti-S-RBD IgG and NAbs in the HCWs' NPI increased by 32.7 and 3.95 times more, respectively. In HCWs' PI, this increment was 5 and 1.42 times more, respectively. There was no statistical association between the history of previous SARS-CoV-2 infection and the titer of anti-S-RBD IgG and NAbs after the booster. The humoral immunity presented a robust increase after receiving the BNT162b2 booster and was more pronounced in NPI.

Diagnostic performance of RT-PCR-based sample pooling strategy for the detection of SARS-CoV-2.

BACKGROUND: The rapid spread of SARS-CoV-2 has created a shortage of supplies of reagents for its detection throughout the world, especially in Latin America. The pooling of samples consists of combining individual patient samples in a block and analyzing the group as a particular sample. This strategy has been shown to reduce the burden of laboratory material and logistical resources by up to 80%. Therefore, we aimed to evaluate the diagnostic performance of the pool of samples analyzed by RT-PCR to detect SARS-CoV-2. METHODS: A cross-sectional study of diagnostic tests was carried out. We individually evaluated 420 samples, and 42 clusters were formed, each one with ten samples. These clusters could contain 0, 1 or 2 positive samples to simulate a positivity of 0, 10 and 20%, respectively. RT-PCR analyzed the groups for the detection of SARS-CoV-2. The area under the ROC curve (AUC), the Youden index, the global and subgroup sensitivity and specificity were calculated according to their Ct values that were classified as high (H: ≤ 25), moderate (M: 26-30) and low (L: 31-35) concentration of viral RNA. RESULTS: From a total of 42 pools, 41 (97.6%) obtained the same result as the samples they contained (positive or negative). The AUC for pooling, Youden index, sensitivity, and specificity were 0.98 (95% CI, 0.95-1); 0.97 (95% CI, 0.90-1.03); 96.67% (95% CI; 88.58-100%) and 100% (95% CI; 95.83-100%) respectively. In the stratified analysis of the pools containing samples with Ct ≤ 25, the sensitivity was 100% (95% CI; 90-100%), while with the pools containing samples with Ct ≥ 31, the sensitivity was 80% (95% CI, 34.94-100%). Finally, a higher median was observed in the Ct of the clusters, with respect to the individual samples (p < 0.001). CONCLUSIONS: The strategy of pooling nasopharyngeal swab samples for analysis by SARS-CoV-2 RT-PCR showed high diagnostic performance.

Factors associated with mortality due to COVID-19 in patients from a public hospital in Tacna, Peru. / Factores asociados a la muerte por COVID-19 en pacientes admitidos en un hospital público en Tacna, Perú.

OBJECTIVE: To describe the clinical, laboratory and treatment characteristics of COVID-19 patients and to determine the factors associated with mortality during hospital stay. Materials and Methods: Retrospective cohort study of adult COVID-19 inpatients. The clinical, laboratory and treatment data were obtained from the medical records of patients from the Hospital Nivel III Daniel Alcides Carrión in Tacna. For the survival analysis we used the Cox proportional hazards model, and we calculated crude and adjusted hazard ratios (HR) with 95% confidence intervals (95% CI). RESULTS: We evaluated 351 patients; 74.1% of them were men. The most common comorbidities were obesity (31.6%), hypertension (27.1%) and diabetes mellitus (24.5%). The median time of hospitalization was 8 days (IQR: 4-15). From the total of patients, 32.9% died during follow-up. The multivariate analysis showed an increased risk of dying associated with the following: age ≥65 years, HR = 3.55 (95% CI: 1.70-7.40); increase in lactate dehydrogenase >720 U/L, HR = 2.08 (95% CI: 1.34-3.22); and oxygen saturation less than 90%, mainly when it was less than 80%, HR = 4.07 (95% CI: 2.10-7.88). In addition, the use of colchicine during treatment showed a protective effect, HR = 0.46 (95% CI: 0.23-0.91). CONCLUSIONS: Risk factors for mortality due to COVID-19 included being older than 65 years, having oxygen saturation less than 90%, and elevated lactate dehydrogenase >720 U/L; colchicine treatment could improve the prognosis of patients.

OBJETIVO: Describir las características demográficas, clínicas, laboratoriales y de tratamiento de pacientes hospitalizados por la COVID-19 y determinar los factores asociados a la mortalidad hospitalaria. MATERIALES Y MÉTODOS: Estudio de cohorte retrospectivo de pacientes adultos hospitalizados por la COVID-19. Se extrajeron datos demográficos, clínicos, laboratoriales y de tratamiento de las historias clínicas de pacientes que ingresaron al Hospital III Daniel Alcides Carrión de Tacna. Para el análisis de supervivencia se empleó el modelo de riesgos proporcionales de Cox y se calcularon los cocientes de riesgo instantáneos (HR) crudos y ajustados con sus respectivos intervalos de confianza al 95% (IC 95%). RESULTADOS: Se evaluó a 351 pacientes, el 74,1% eran hombres; las comorbilidades más comunes fueron obesidad (31,6%), hipertensión (27,1%) y diabetes mellitus (24,5%). La mediana de tiempo de hospitalización fue 8 días (RIC: 4-15). El 32,9% falleció durante el seguimiento. El análisis multivariado mostró un aumento del riesgo de morir asociado a la edad ≥65 años, HR = 3,55 (IC 95%: 1,70-7,40); al incremento de lactato deshidrogenasa >720 U/L, HR = 2,08 (IC 95%: 1,34-3,22); y a la saturación de oxígeno por debajo del 90%, principalmente cuando fue menor al 80%, HR = 4,07 (IC 95%: 2,10-7,88). Además, el uso de colchicina en el tratamiento tuvo un efecto protector, HR = 0,46 (IC 95%: 0,23-0,91). CONCLUSIONES: Los factores asociados a muerte por la COVID-19 incluyeron ser mayor de 65 años, tener saturación de oxígeno menor de 90% y elevación del lactato deshidrogenasa >720 U/L; el tratamiento con colchicina podría mejorar el pronóstico de los pacientes.