Hospital-Wide SARS-CoV-2 seroprevalence in health care workers in a Spanish teaching hospital

Introduction

Methods

Results

Conclusions

SARS-CoV-2 new infections among health-care workers after the first dose of the BNT162b2 mRNA COVID-19 vaccine. A hospital-wide cohort study

OBJECTIVES

To evaluate the effect of mRNA severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination on the incidence of new SARS-CoV-2 infections in health-care workers (HCW).

METHODS

The evolution of the incident rate of microbiologically confirmed SARS-CoV-2 infection in a cohort of 2590 HCW after BNT162b2 mRNA SARS-CoV-2 vaccination, compared with the rate in the community (n = 170 513) was evaluated by mixed Poisson regression models.

RESULTS

A total of 1820 HCW (70.3% of total) received the first dose of the BNT162b2 mRNA vaccine between 10 January and 16 January 2021, and 296 (11.4%) received it the following week. All of them completed vaccination 3 weeks later. Incidence rates of SARS-CoV-2 infection after the first dose of mRNA SARS-CoV-2 vaccine declined by 71% (Incidence Rate Ratio (IRR) 0.286, 95% CI 0.174-0.468; p < 0.001) and by 97% (IRR 0.03, 95% CI 0.013-0.068; p < 0.001) after the second dose, compared with the perivaccine time. SARS-CoV-2 incidence rates in the community (with a negligible vaccination rate) had a much lower decline: 2% (IRR 0.984, 95% CI 0.943-1.028; p 0.47) and 61% (IRR 0.390, 95% CI 0.375-0.406; p < 0.001) for equivalent periods. Adjusting for the decline in the community, the reduction in the incident rates among HCW were 73% (IRR 0.272, 95% CI 0.164-0.451 p < 0.001) after the first dose of the vaccine and 92% (IRR 0.176, 95% CI 0.033-0.174; p < 0.001) after the second dose.

CONCLUSIONS

mRNA SARS-CoV-2 vaccination is associated with a dramatic decline in new SARS-CoV-2 infection among HCW, even before the administration of the second dose of the vaccine.

Impact of Previous Coronavirus Disease 2019 on Immune Response After a Single Dose of BNT162b2 Severe Acute Respiratory Syndrome Coronavirus 2 Vaccine

Immune response after a single dose of BNT162b2 vaccine was markedly increased in subjects with previous severe acute respiratory syndrome coronavirus 2 infection, reaching similar immunoglobulin titers to those elicited by the full 2 doses in naive cases, and increased modestly after the second dose. These data may inform the priority of the boosting dose.

Hospital-Wide SARS-CoV-2 seroprevalence in health care workers in a Spanish teaching hospital

INTRODUCTION

Hospital-wide SARS-CoV-2 seroprevalence is rarely explored and can identify areas of unexpected risk. We determined the seroprevalence against SARS-CoV-2 in all health care workers (HCW) at a hospital.

METHODS

Cross-sectional study (14-27/04/2020). We determined SARS-CoV-2 IgG by ELISA in all HCW including external workers of a teaching hospital in Madrid. They were classified by professional category, working area, and risk for SARS-CoV-2 exposure.

RESULTS

Among 2919 HCW, 2590 (88,7%) were evaluated. The mean age was 43.8 years (SD 11.1), and 73.9% were females. Globally, 818 (31.6%) workers were IgG positive with no differences for age, sex or previous diseases. Of these, 48.5% did not report previous symptoms. Seropositivity was more frequent in high- (33.1%) and medium- (33.8%) than in low-risk areas (25.8%, p=0.007), but not for hospitalization areas attending COVID-19 and non-COVID-19 patients (35.5 vs 38.3% p>0.05). HWC with a previous SARS-CoV2 PCR-positive test were IgG seropositive in 90.8%. By multivariate logistic regression analysis seropositivity was significantly associated with being physicians (OR 2.37, CI95% 1.61-3.49), nurses (OR 1.67, CI95% 1.14-2.46), nurse assistants (OR 1.84, CI95% 1.24-2.73), HCW working at COVID-19 hospitalization areas (OR 1.71, CI95% 1.22-2.40), non-COVID-19 hospitalization areas (OR 1.88, CI95% 1.30-2.73), and at the Emergency Room (OR 1.51, CI95% 1.01-2.27).

CONCLUSIONS

Seroprevalence uncovered a high rate of infection previously unnoticed among HCW. Patients not suspected of having COVID-19 as well as asymptomatic HCW may be a relevant source for nosocomial SARS-CoV-2 transmission.

Antiviral activity of the natural alkaloid anisomycin against dengue and Zika viruses

Flaviviruses constitute a public health concern because of their global burden and the lack of specific antiviral treatment. Here we investigated the antiviral activity of the alkaloid anisomycin against dengue (DENV) and Zika (ZIKV) viruses. At non-cytotoxic concentrations, anisomycin strongly inhibited the replication of reference strains and clinical isolates of all DENV serotypes and Asian and African strains of ZIKV in Vero cells. Anisomycin also prevented DENV and ZIKV multiplication in human cell lines. While initial steps of DENV and ZIKV replicative cycle were unaffected, a high inhibition of viral protein expression was demonstrated after treatment with anisomycin. DENV RNA synthesis was strongly reduced in anisomycin treated cultures, but the compound did not exert a direct inhibitory effect on 2' O-methyltransferase or RNA polymerase activities of DENV NS5 protein. Furthermore, anisomycin-mediated activation of p38 signaling was not related to the antiviral action of the compound. The evaluation of anisomycin efficacy in a mouse model of ZIKV morbidity and mortality revealed that animals treated with a low dose of anisomycin exhibited a significant reduction in viremia levels and died significantly later than the control group. This protective effect was lost at higher doses, though. In conclusion, anisomycin is a potent and selective in vitro inhibitor of DENV and ZIKV that impairs a post-entry step of viral replication; and a low-dose anisomycin treatment may provide some minimal benefit in a mouse model.

Antiherpes simplex virus type 2 activity of the antimicrobial peptide subtilosin

AIMS

In this study, we evaluated the antiviral activity of subtilosin, a cyclical peptide isolated from Bacillus amyloliquefaciens, against herpes simplex virus type 2 (HSV-2) in cell cultures and we investigated subtilosin mode of action.

METHODS AND RESULTS

We determined, using a virus yield inhibition assay, that noncytotoxic concentrations of subtilosin inhibit HSV-2 replication in Vero cell cultures. Subtilosin strongly inhibited extracellular and total virus production even when it was added at 8 h postinfection indicating that not only virus release but also viral particle formation is impeded by the antiviral peptide. Although viral glycoprotein gD level of expression is not affected by the bacteriocin, an altered pattern of gD intracellular localization was detected by immunofluorescence assay in subtilosin-treated culture. On the other hand, at high concentrations, subtilosin displays virucidal action.

CONCLUSIONS

Subtilosin displays antiviral and virucidal actions against HSV-2. The target of subtilosin inhibitory effect would be late stages of the viral replicative cycle such as viral glycoprotein intracellular transport.

SIGNIFICANCE AND IMPACT OF THE STUDY

Given its antimicrobial activity and its safety for human tissues, subtilosin could represent a valuable alternative to be considered in the development of new microbicide formulations.

Effect of simultaneous use of highly active antiretroviral therapy on survival of HIV patients with tuberculosis

INTRODUCTION

The optimal timing for initiation of highly active antiretroviral therapy (HAART) in patients with AIDS and tuberculosis (TB) is an unresolved question. To assess the effect of HAART on the survival of patients with TB, we designed this study.

METHODS

We selected all HIV patients included in the COMESEM cohort with TB diagnosis after 1996. Clinical and epidemiological data were registered. We compared patients who started HAART at the diagnosis of TB [simultaneous therapy (ST)] or not. Survival was assessed by Cox analysis.

RESULTS

Among the 6934 HIV patients included in the cohort, 1217 patients had TB, 322 of them (26.5%) after 1996. At the time of TB diagnosis, 45% of them started HAART (ST). There were no differences between groups regarding basal characteristics, except for a lower viral load in ST patients. ST therapy was associated with improved survival (hazard ratio 0.38; 95% confidence interval 0.20 to 0.72, P = 0.003). By univariate analysis, survival was also associated with no endovenous drug use and a later year of TB diagnosis. After adjusting for other prognostic variables, by Cox multivariate analysis, ST remained robustly associated with improved survival (hazard ratio 0.37; 95% confidence interval 0.17 to 0.66, P = 0.001).

CONCLUSIONS

Simultaneous HAART and TB treatment in HIV patients with TB is associated with improved survival.

The changing pattern of tuberculosis and HIV co-infection in immigrants and Spaniards in the last 20 years

OBJECTIVES

To evaluate the impact of immigration on tuberculosis (TB)-HIV co-infection in Spain in a prospective cohort of HIV patients.

METHODS

Among 7761 HIV patients, we evaluated 1284 with at least one episode of TB between 1987 and 2006. Variables were compared between immigrants and Spaniards.

RESULTS

Incidence of TB decreased from 20 to five cases per 100 patient-years in 2006 (P<0.01) and was always higher in immigrants than in Spaniards. The proportion of immigrants increased, reaching almost 50% of both new cases of HIV and TB-HIV co-infection in 2006. In 34.4% of patients, TB and HIV infection were diagnosed within the same year; simultaneous diagnosis was more frequent in immigrants (83.3%vs. 16.7%, P<0.001). Mortality was associated independently with age [hazard ratio (HR) 1.03, 95% confidence interval (CI) 1.01-1.05], TB diagnosis before 1996 (HR 2.6, 95% CI 1.8-3.6), use of highly active antiretroviral treatment (HR 0.494, 95% CI 0.37-0.66) and CD4 cell count at TB diagnosis (HR 0.996, 95% CI 0.995-0.997).

CONCLUSIONS

Immigrants have a major impact on the incidence of TB in HIV patients, slowing down the decreasing trend in Spain. Simultaneous diagnosis of the co-infection in immigrants reveals a need to intensify HIV case finding in immigrants in Spain.

Economic evaluation of assistance to HIV patients in a Spanish hospital

BACKGROUND

Little is known about the global effects of HAART on the use of medical resources after the complete implementation of this therapy in Spain. This study was designed to determine the use of medical resources and the costs of health care for HIV-infected patients.

METHODS

All patients with HIV infection who came to our institution during the year 2002 were included in the study. We analyzed the global assistance data and pharmaceutical costs during the year. Costs were calculated based on a unitary cost for DRG and an officially assigned standard cost for outpatient clinic, visits to the day care unit and to the emergency room (ER), outpatient surgery, and total costs of pharmacy.

RESULTS

The total cost for HIV-related health care assistance was euro739,048. The cost related to admissions was euro150,766.60; euro8631 per first visit and euro49,199.40 per successive visit; euro5085.10 per day care unit; euro14,920 per outpatient surgery; euro7655.70 per ER visit; and euro491,342.40 per antiretroviral treatment. A significant proportion of the total outpatient assistance was given by physicians other than HIV specialists, namely, 63% of the costs attributed to the first visit and 41% per successive visit.

CONCLUSION

More than 50% of the costs of caring for HIV-infected patients are still attributed to antiretroviral therapy. Specialists other than infectious disease specialists provide a significant proportion of outpatient assistance. A method to control HIV costs is greatly needed.

Inhibition of cell fusion in Junin virus-infected cells by sera from Argentine hemorrhagic fever patients

BACKGROUND

Junin virus (JV), a member of the Arenaviridae family, is the etiological agent of Argentine hemorrhagic fever (AHF). A low pH-pulse, induces fusion of Vero cells infected with JV to form syncytia, whose production can be inhibited by neutralizing antibodies against the JV major glycoprotein.

OBJECTIVES

To characterize the existence of an antifusogenic activity present in sera obtained from natural infections of AHF over a 20-year period and to study both the fusogenic activity of one pathogenic and two attenuated strains of JV in Vero cells, at different pH. The study sample consisted of sera obtained from two provinces in the Argentine Republic. Vero cells grown in monolayers, were infected with different strains of JV and a 2 h pulse, at different pH, was performed. Syncytium production was evaluated 12 h later, after staining with Giemsa. Neutralization tests against the attenuated strain XJCl3 were carried out and the antifusogenic activity of immunosera was studied by incubating serum with JV-infected Vero cells. Also the fusion activity in Vero cells infected with three JV strains was assayed.

RESULTS AND CONCLUSIONS

A pathogenic strain XJ exhibited the highest fusogenic activity at pH 5. Syncytium formation was prevented by patients' sera obtained from different geographical locations, independently of time of infection. However, when Vero cells were infected with XJ, a significant reduction of syncytium production was observed, though the level of inhibition was lower than that detected in other JV strains-infected cells. These results could be explained by the existence of a conserved domain on JV proteins and also antigenic heterogeneity among strains.

A randomized controlled trial investigating the efficacy and safety of switching from a protease inhibitor to nevirapine in patients with undetectable viral load

OBJECTIVE

To assess the antiviral efficacy and safety of switching from a protease inhibitor (PI) to nevirapine in patients with long-term HIV-1 RNA suppression on PI-containing regimens, and to assess its influence in the adherence to treatment.

METHODS

In an open-label multicentre study, 160 HIV-infected patients with undetectable viral load for at least 6 months on a PI-containing regimen were randomized to either continue with their PI regimen (n=79) or replace PI with nevirapine (n=81). Clinical assessment included plasma HIV-1 RNA, blood chemistry, haematology, lymphocyte counts and adverse events reports. Adherence to treatment and lipodystrophy syndrome were assessed by patient self-reporting.

RESULTS

Treatment efficacy was equivalent in the two arms, for patients with viral loads either above or below 100 000 HIV-1 RNA copies/mL. The increase in CD4 cell count was significant in both arms (P<0.00001) but the average CD4 cell count at 48 weeks was slightly higher in the nevirapine arm (596 vs. 569; P=0.1588). The number of patients with severe hypertriglyceridaemia (>400 mg/dL) after 48 weeks of treatment decreased in the nevirapine arm (from 11 to six), but increased in the PI arm (from four to 11) and led to treatment discontinuation in two patients. Lipodystrophy changes increased in 15% of patients in the PI arm but decreased in 4% of patients in the nevirapine arm. Finally, although adherence was similar in the two arms, patients reported that it required significantly less effort to stay on treatment in the nevirapine arm. Conclusions The results indicate that switching from PI to nevirapine is as effective as continuing with PI for maintaining viral control, even in patients with baseline viral load above 100,000 copies/mL. In addition, reductions in hypertriglyceridaemia and lipodystrophy and in the effort required to stay on treatment were observed.

[Multicenter cohort of patients with HIV infection in the Madrid south-eastern metropolitan crown (COMESEM): basis, organization and initial results]

BACKGROUND

In order to evaluate changes related to the effect of new anti-retroviral agents and preventive programs, cohort studies of patients with HIV in our environment are needed.

METHODS

Cohort study of patients diagnosed of HIV infection in the five hospitals included in the Madrid metropolitan south-eastern crown (COMESEM), which attend a population of 1,300,000 inhabitants.

RESULTS

A total of 5,532 patients had been recruited until August 2001 (with a follow-up of 34,227 patients-year). The male/female ratio was 3/1. As for the transmission mechanism, 72.9% were parenteral drug users (PDU), 13.7% heterosexuals (HTX) and 8% of males having sex with males (MSM). The maximal figure of diagnosis per year corresponded to 1991 for PDU, 1993 for MSM and 1995 for heterosexuals. A decline in the number of diagnosed patients was observed for all groups, but MSM showed an increase in the year 2001 for the first time. Notably, among HTX, a growing and sustained trend was observed of patients not born in Spain (0% in 1993 and 50% in 2001; p < 0.001).

CONCLUSIONS

Establishing a large cohort of HIV infected patients based upon medium-sized hospitals is possible. The analysis of data derived from this cohort allows the early detection of changes in the clinical and epidemiological profile of HIV infection.

Assessing clinical probability of organic disease in patients with involuntary weight loss: a simple score

BACKGROUND: Involuntary weight loss (IWL) is a frequent complaint with a difficult diagnosis. Any one of a number of different diseases may be the source of the symptom. However, there is no universal clinical protocol that can help physicians study this complex syndrome. METHODS: In March 1998, we defined a diagnostic protocol for the study of IWL. IWL was defined as an involuntary and documented weight loss of at least 5% of the usual body weight in the previous 3 months. We analyzed 78 consecutive patients with IWL who came to our clinic between March 1998 and December 2000. RESULTS: An organic disease was found in 56% of cases; cancer, metabolic and digestive diseases were the most common entities. Psychiatric problems were found in 33% of cases. After extensive study, an idiopathic group of 11% was identified. The variables that were independently predictive of a final diagnosis of organic disease were: age>50 years (OR: 8.6, CI 95%: 1.7-43.6), psychiatric symptoms (OR: 0.2, CI 95%: 0.1-0.8), smoking (OR: 14.3, CI 95% 2.3-74), the presence of guide symptoms (OR: 8.0, CI 95%: 1.8-34.4), and anemia (OR: 3.1, CI 95%: 2.5-387). Sixteen percent of the patients died, more often those suffering from organic diseases. Based on multivariate regression coefficients, a clinical risk score was established. CONCLUSIONS: IWL is a complex and frequent syndrome with a 16% rate of mortality during the first year. A protocol based on clinical data can help in the management of IWL. Our clinical prediction rule may help physicians to identify those patients with IWL who are likely to have an underlying organic disease.

Involvement of vacuolar proton ATPase in Junin virus multiplication

The role of vacuolar-proton ATPase (V-H+ ATPAse) on Junin virus (JV) replication was evaluated by analyzing the effect of specific inhibitors of the enzyme activity on different steps of virus multiplication cycle. The presence of the macrolide antibiotics bafilomycin A1 and concanamycin A during the first two hours of infection caused a significant reduction of extracellular infectious virus production and viral protein expression in Vero and BHK-21 cells. The inhibitory action of the compounds was mainly exerted at an early stage of the JV multiplication cycle, without affecting virus attachment to the cell but preventing virus penetration. A correlation between the inhibitory action of the compounds on intracellular compartments acidification and the reduction of JV yield was observed. The addition of concanamycin A at different times after infection indicated that the compound also interferes with the release of infectious particles to the extracellular medium. Although, intracellular transport of JV glycoproteins to the cell membrane, seems not to be affected as revealed by immunofluorescence staining. The results confirm that JV enters into the cell through the endocytic pathway as previously suggested by using lysosomotropic compounds.

Analysis of viral glycoproteins by glycosidic digestion inside a polyacrylamide gel

We adapted the method described by Cleveland et al. (1977); (Peptide mapping by limited proteolysis in sodium dodecyl sulphate and analysis by gel electrophoresis. J. Biol. Chem. 252, 1102-1106) to study the glycosidic residues linked to the viral glycoproteins of two enveloped viruses: Junin virus (JV) and rubella virus (RV). Radioiodinated glycoproteins were obtained from purified virions, isolated from SDS-polyacrylamide gels and then hydrolysed by specific glycosidases inside a second gel. N-linked oligosaccharides, mannose and galactose were found as terminal residues in the JV-G1 glycoprotein. Mannose and N-glycans of complex hybrid type were present on RV glycoproteins.

Effects of reducing, oxidizing and alkylating agents on early steps of Junin virus multiplication

The action of reducing, oxidizing and thiol-alkylating agents on early steps of Junin virus (JV) multiplication in Vero cells was investigated. The presence of reducing agents during virus adsorption as well as incubation of viral particles with these compounds before infection enhanced JV infectivity. On the contrary, the thiol-alkylating agent 5,5' dithiobis (2-nitrobenzoic acid) and the oxidizing compound potassium periodate showed an inhibitory effect, suggesting that sulfhydryl groups, and certain sugar moieties of viral glycoproteins play an important role in the first steps of JV infection. Also enzymatic treatment of cell monolayers and addition of concanavalin A to cultures prior to infection suggest that cellular glycoproteins are involved in virus attachment.

Inhibition of foot and mouth disease virus (FMDV) uncoating by a plant-derived peptide isolated from Melia azedarach L leaves

Meliacine (MA), a peptide isolated from leaves of the high plant Melia azedarach L inhibited the multiplication of foot and mouth disease virus (FMDV) in BHK-21 cells. In this report, we establish that the MA-inhibitable process takes place within the first hour of the viral reproductive cycle. MA had no virucidal effect and did not affect adsorption and penetration of the virus in cells. In experiments with neutral red-labeled virus, it was found that MA significantly suppressed the development of photoresistance of the virus in infected cells. In untreated cultures nearly all virus which adsorbed to cells was uncoated within 1 h at 37 degrees C, whereas in treated cultures, even after 3 h only 3% of the virus was uncoated. Labeling of BHK-21 cells with acridine orange showed that MA affects the pH of intracellular acidic vesicles. Therefore, it is concluded that MA prevents the process of uncoating of FMDV in BHK-21 cells by inhibiting vacuolar acidification.

In vitro anti-Junin virus activity of a peptide isolated from Melia azedarach L. leaves

Meliacine, a peptide isolated from leaves of Melia azedarach L. inhibited the multiplication of Junin virus in Vero cells treated with the compound before infection (pre-treatment) or immediately after virus adsorption. Analysis of early events following infection demonstrated that meliacine blocks virus penetration by preventing the uncoating step. The addition of meliacine at different times after infection indicated that meliacine also interferes with the release of infectious particles to the extracellular medium and inhibits the low-pH-induced fusion of infected cells. Intracellular transport of viral glycoproteins to the cell membrane was not affected by meliacine, as revealed by immunofluorescence staining. Taken together, these results suggest that meliacine affects two events of the virus replicative cycle that require membrane fusion: uncoating and budding.

Low-pH-induced fusion of Vero cells infected with Junin virus

Junin virus (JV) infected Vero cells were used to investigate virus capacity to induce cell-cell fusion. Polykaryocyte formation due to JV was found to be pH and temperature-dependent. A reduced fusion activity was detected on BHK-21 cells. Different JV-strains exhibited a similar extent and pH dependence of their fusion activity. Neutralizing antibodies against the main viral glycoprotein (GP38) inhibited syncytium production and GP38 conformational changes in response to acid treatment were detected by an immunoprecipitation assay.

The entry of Junin virus into Vero cells

The entry mechanism of Junin virus (JV) into Vero cells was studied analyzing the effect of lysosomotropic compounds and acid pH on JV infection. Ammonium chloride, amantadine, chlorpheniramine and procaine inhibited JV production. The action of ammonium chloride was exerted at early times of infection. Virus internalization was inhibited and viral protein expression was not detected. When the extracellular medium was buffered at low pH, the ammonium chloride induced block on JV infection was overcome. Furthermore, JV was able to induce fusion of infected cells at pH 5.5 leading to polykaryocyte formation. Taken together, these results demonstrate that JV entry occurs through an endocytic mechanism requiring a low pH dependent membrane fusion.

[Lysosomotropic compounds inhibiting the multiplication of Junin virus]

A number of lysosomotropic compounds of diverse chemical structure, ammonium chloride, procaine and chlorpheniramine, were found to inhibit the infection of Vero cells by Junín virus. Viral replication was almost totally inhibited by 15 mM ammonium chloride, when added either before or within the first hour of infection and a significant inhibition (97.8%) was observed when it was added 8 hours after infection. These results agree with a model which postulates that arenavirus entry occurs by receptor-mediated endocytosis.

Lectin affinity of Junin virus glycoproteins

We studied the binding of Junin virus (Arenaviridae) glycoproteins, G1 and G2, to two insolubilized lectins. The results showed that mannose, N-acetyl-glucosamine and galactose residues were exposed on G2, while only the latter predominated on G1. Heterogeneity of carbohydrate chains was found in G2, the only glycoprotein that was iodinated by the lactoperoxidase method.