The importance of prevalence and pre-test probability on the microbiological diagnosis of SARS-CoV-2: the case of Spain in 2020

ANDRÉS CANUT-BLASCO, CARMEN GÓMEZ-GONZÁLEZ, RAQUEL BARBERO-HERRANZ, ISMAEL BARBERO-MARTÍNEZ, EIDER ABASOLO-OSINAGA, ON BEHALF OF ARABA UNIVERSITY HOSPITAL GROUP ON COVID-19 DIAGNOSTIC TESTS

Published: 21 July 2023

http://www.doi.org/10.37201/req/033.2023

Objectives. The aim of this work was to estimate the conditioned probability for the diagnosis of SARS-CoV-2 infection with reverse transcription polymerase chain reaction (RT-PCR),
viral antigen rapid diagnostic tests (Ag-RDT), and antibody detection tests depending on the prevalence in the specific healthcare settings in Spain in 2020, and on the pre-test probability (PTP) according to the clinical situation, age and unknown or close contacts of the patient.
Material and methods. Performance parameters of tests were obtained from literature. Prevalence data and PTP were obtained from Spanish sources and a survey, respectively. The post-test probability is the positive predictive value (PPV) when test is positive. For negative result, we also calculated the probability of having the infection (false negatives).
Results. For both RT-PCR and viral Ag-RDT, the lowest PPV values were for the population screenings. This strategy proved to be useful in ruling out infection but generates a high number of false positives. At individual level, both tools provided high PPV (≥ 97%) when the PTP values are over 35%. In seroprevalence studies, though the specificity of IgG alone tests is high, under low seroprevalence, false positives cannot be avoided. Total antibodies tests are useful for diagnosis of COVID-19 in those doubtful cases with RT-PCR or Ag-RDT tests being repeatedly negative.
Conclusions. The interpretating of results depends not only on the accuracy of the test, but also on the prevalence of the infection in different settings, and the PTP associated to the patient before performing the test.

Rev Esp Quimioter 2023; 36(5): 498-506 [Full-text PDF]

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Recommendations for the prevention of healthcare-associated infections in nursing homes

EMILIO BOUZA, ÁNGEL ASENSIO, JOSÉ AUGUSTO GARCÍA NAVARRO, PEDRO GONZÁLEZ, MIGUEL ÁNGEL ACOSTA BENITO, JESÚS AGUILAR, JOSÉ BARBERÁN, JULIANA CABRERA, JESÚS DÍEZ-MANGLANO, CARLOS FERNÁNDEZ, MARÍA FERNANDEZ-PRADA, GUADALUPE FONTÁN, JOSÉ MIGUEL CISNEROS, BELÉN LORENZO-VIDAL, ADELA MARTÍN OLIVEROS, PALOMA NAVAS, ESTEBAN PALOMO, MARTHA KESTLER

Published: 19 July 2023

http://www.doi.org/10.37201/req/078.2023

Nursing homes (NH) conceptually should look as much like a home as possible. However NH have unquestionable similarities with a nosocomium as they are places where many patients with underlying diseases and comorbidities accumulate. There is evidence of transmission of microorganisms between residents and between residents and caregivers. We have not found any recommendations specifically aimed at the prevention of nosocomial infections in NH by the major Public Health Agencies and, therefore, the Health Sciences Foundation (Fundación de Ciencias de la Salud) has convened a series of experts and 14 Spanish scientific societies to discuss recommendations that could guide NH personnel in establishing written programs for the control and reduction of these infections. The present document is the result of these deliberations and contains suggestions for establishing such control programs on a voluntary and flexible basis in NH. We also hope that the document can help the health authorities to encourage this control activity in the different territorial areas of Spain. In our opinion, it is necessary to draw up a written plan and establish the figure of a coordinator or person responsible for implementing these projects. The document includes
measures to be implemented and ways of quantifying the reality of different problems and of monitoring the impact of the measures established.

Rev Esp Quimioter 2023; 36(6): 552-561 [Full-text PDF]  [Supplementary material PDF]

Analysis of the incidence and epidemiology of non-tuberculous mycobacterial infections in the health area III of Aragón

TINA HERRERO, MARIA ISABEL SANJOAQUIN, MIGUEL LAFUENTE, LUISA MARGARITA CABRERA, MARÍA BETRÁN, ANA MARIA CAMÓN

Published: 17 July 2023

http://www.doi.org/10.37201/req/019.2023

Objectives. The main objective of our investigation was to know the incidence and epidemiology of non-tuberculous mycobacteria (NTM) in our area and the prevalence of comorbidities in patients with MNT infection. As secondary objectives, we studied the distribution by species of MNT, the forms of disease and the type of sample used for its diagnosis.
Material and methods. A retrospective study was carried out in which all the isolates of mycobacteria carried out by the microbiology laboratory of the Hospital Clínico Universitario Lozano Blesa of Zaragoza during the period between January 1, 2011 and December 31, 2018 were included.
Results. A total of 533 mycobacteria were isolated, of which 295 (55.35%) were tuberculosis (MTB) and 238 (44.65%) were MNT. Of the whole MNT isolates, only 15.54% were considered clinically significant. Twenty-one species were identified being the most frequent: M. gordonae (26.89%), M. fortuitum (19.75%) and M. avium (16.39%). 32.72% of the MNT isolates were found in people over 70 years of age.
Conclusions. We can confirm that the reported number of MNT isolates in our area is higher than in previous periods. MNT infection is more common in men and those older than 70 years. The epidemiology, especially the risk factors, of MNT
disease is changing

Rev Esp Quimioter 2023; 36(5): 492-497 [Texto completo PDF]

In vitro assessment of the combined effect of letermovir and sirolimus on cytomegalovirus replication

ESTELA GIMÉNEZ, MANUEL GUERREIRO, ROBERTO GOZALBO-ROVIRA, CRISTOBAL AGUILAR, ELISEO ALBERT, JOSÉ LUIS PIÑANA, CARLOS SOLANO, DAVID NAVARRO

Published: 28 June 2023

http://www.doi.org/10.37201/req/016.2023

Introduction. Letermovir (LMV) is used for prophylaxis of cytomegalovirus (CMV) reactivation and end-organ disease in adult CMV-seropositive allogeneic hematopoietic stem cell transplant recipients (allo-HSCT). In turn, sirolimus (SLM) which displays in vitro anti-CMV activity, is frequently employed for prophylaxis of Graft vs. Host disease in allo-HSCT. Here, we aimed at assessing whether LMV and SLM used in combination may act synergistically in vitro on inhibiting CMV replication.
Material and methods. The antiviral activity of LMV and SLM alone or in combination was evaluated by a checkerboard assay, using ARPE-19 cells infected with CMV strain BADrUL131-Y. LMV and SLM were used at concentrations ranging from 24 nM to 0.38 nM and 16 nM to 0.06 nM, respectively.
Results. The mean EC50 for LMV and SLM was 2.44 nM (95% CI, 1.66-3.60) and 1.40 nM (95% CI, 0.41-4.74), respective. LMV and SLM interaction yielded mainly additive effects over the range of concentrations tested.
Conclusion. The additive nature of the combination of LMV and SLM against CMV may have relevant clinical
implications in management of CMV infection in allo-HSCT recipients undergoing prophylaxis with LMV.

Rev Esp Quimioter 2023; 36(5): 526-530 [Full-text PDF]