Cytokine expression and mortality risk among COVID-19 hospitalized patients over 60 years of age in a referral hospital in Cartagena, Colombia

Background

Cytokine dysregulation in COVID-19 patients aged over 60 has been associated to adverse outcomes. While serum levels have been studied, cellular expression, particularly in Afro-Colombians, remains understudied. This research aims to describe cytokine expression in peripheral blood leukocytes and its association with adverse outcomes in COVID-19 patients aged over 60 at Cartagena's referral hospital.

Methods

A cohort study was conducted, encompassing severe and critical cases of COVID-19 between November 2021 and February 2022. At baseline, the cellular expression level of cytokines IL-2, IL-4, IL-6, IL-10, TNF-α and IFN-γ was assessed using flow cytometry. Additionally, various biochemical, hematological, and coagulation markers were evaluated. The main outcome was time to death.

Results

Among the 50 enrolled participants, the median age was 76.5 years, 60% were male, 60% were admitted to the ICU, and 42% died. Lactate dehydrogenase and hemoglobin were the only markers that differed between fatal and surviving cases. Regarding cytokines, the level of IL-6 expression was associated with an increased risk of death. Specifically, a one percent increase in the expression was associated with a 7.3% increase in the risk of death. Stratifying the analysis by death and ICU admission, the median expression level remained high in fatal cases who were admitted to the ICU.

Conclusions

Our findings revealed a significant association between high cellular expression levels of IL-6 and an increased risk of mortality. These results provide valuable scientific insights that could inform the prioritization of case management, providing especially advantageous for the vulnerable Afro-Colombian group.

Sampling is decisive to determination of Leishmania (Viannia) species

BACKGROUND

Accuracy of molecular tools for the identification of parasites that cause human cutaneous leishmaniasis (CL) could largely depend on the sampling method. Non-invasive or less-invasive sampling methods such as filter paper imprints and cotton swabs are preferred over punch biopsies and lancet scrapings for detection methods of Leishmania based on polymerase chain reaction (PCR) because they are painless, simple, and inexpensive, and of benefit to military and civilian patients to ensure timely treatment. However, different types of samples can generate false negatives and there is a clear need to demonstrate which sample is more proper for molecular assays.

METHODOLOGY

Here, we compared the sensitivity of molecular identification of different Leishmania (Viannia) species from Peru, using three types of sampling: punch biopsy, filter paper imprint and lancet scraping. Different composite reference standards and latent class models allowed to evaluate the accuracy of the molecular tools. Additionally, a quantitative PCR assessed variations in the results and parasite load in each type of sample.

PRINCIPAL FINDINGS

Different composite reference standards and latent class models determined higher sensitivity when lancet scrapings were used for sampling in the identification and determination of Leishmania (Viannia) species through PCR-based assays. This was consistent for genus identification through kinetoplastid DNA-PCR and for the determination of species using FRET probes-based Nested Real-Time PCR. Lack of species identification in some samples correlated with the low intensity of the PCR electrophoretic band, which reflects the low parasite load in samples.

CONCLUSIONS

The type of clinical sample can directly influence the detection and identification of Leishmania (Viannia) species. Here, we demonstrated that lancet scraping samples consistently allowed the identification of more leishmaniasis cases compared to filter paper imprints or biopsies. This procedure is inexpensive, painless, and easy to implement at the point of care and avoids the need for anesthesia, surgery, and hospitalization and therefore could be used in resource limited settings for both military and civilian populations.

Molecular characterization of carbapenemase-producing Enterobacterales in a tertiary hospital in Lima, Peru

Carbapenemase-producing Enterobacterales (CPE) are a growing threat to global health and the economy. Understanding the interactions between resistance and virulence mechanisms of CPE is crucial for managing difficult-to-treat infections and informing outbreak prevention and control programs. Here, we report the characterization of 21 consecutive, unique clinical isolates of CPE collected in 2018 at a tertiary hospital in Lima, Peru. Isolates were characterized by phenotypic antimicrobial susceptibility testing and whole-genome sequencing to identify resistance determinants and virulence factors. Seven Klebsiella pneumoniae isolates were classified as extensively drug-resistant. The remaining Klebsiella, Enterobacter hormaechei, and Escherichia coli isolates were multidrug-resistant. Eighteen strains carried the metallo-β-lactamase NDM-1, two the serine-carbapenemase KPC-2, and one isolate had both carbapenemases. The blaNDM-1 gene was located in the truncated ΔISAba125 element, and the blaKPC-2 gene was in the Tn4401a transposon. ST147 was the most frequent sequence type among K. pneumoniae isolates. Our findings highlight the urgent need to address the emergence of CPE and strengthen control measures and antibiotic stewardship programs in low- and middle-income settings.IMPORTANCEGenomic surveillance of antimicrobial resistance contributes to monitoring the spread of resistance and informs treatment and prevention strategies. We characterized 21 carbapenemase-producing Enterobacterales collected at a Peruvian tertiary hospital in 2018, which exhibited very high levels of resistance and carried numerous resistance genes. We detected the coexistence of carbapenemase-encoding genes (blaNDM-1 and blaKPC-2) in a Klebsiella pneumoniae isolate that also had the PmrB(R256G) mutation associated with colistin resistance. The blaKPC-2 genes were located in Tn4401a transposons, while the blaNDM-1 genes were in the genetic structure Tn125 (ΔISAba125). The presence of high-risk clones among Klebsiella pneumoniae (ST11 and ST147) and Escherichia coli (ST410) isolates is also reported. The study reveals the emergence of highly resistant bacteria in a Peruvian hospital, which could compromise the effectiveness of current treatments and control.

Prediction models of COVID-19 fatality in nine Peruvian provinces: A secondary analysis of the national epidemiological surveillance system

There are initiatives to promote the creation of predictive COVID-19 fatality models to assist decision-makers. The study aimed to develop prediction models for COVID-19 fatality using population data recorded in the national epidemiological surveillance system of Peru. A retrospective cohort study was conducted (March to September of 2020). The study population consisted of confirmed COVID-19 cases reported in the surveillance system of nine provinces of Lima, Peru. A random sample of 80% of the study population was selected, and four prediction models were constructed using four different strategies to select variables: 1) previously analyzed variables in machine learning models; 2) based on the LASSO method; 3) based on significance; and 4) based on a post-hoc approach with variables consistently included in the three previous strategies. The internal validation was performed with the remaining 20% of the population. Four prediction models were successfully created and validate using data from 22,098 cases. All models performed adequately and similarly; however, we selected models derived from strategy 1 (AUC 0.89, CI95% 0.87-0.91) and strategy 4 (AUC 0.88, CI95% 0.86-0.90). The performance of both models was robust in validation and sensitivity analyses. This study offers insights into estimating COVID-19 fatality within the Peruvian population. Our findings contribute to the advancement of prediction models for COVID-19 fatality and may aid in identifying individuals at increased risk, enabling targeted interventions to mitigate the disease. Future studies should confirm the performance and validate the usefulness of the models described here under real-world conditions and settings.

Development and validation of a vero cell-based suspension method for the detection of Zika virus

OBJECTIVE.

To develop and validate a cell suspension method using Vero 76 cells for culturing Zika virus (ZIKV) based on infection of detached freshly seeded cells.

MATERIAL AND METHODS.

Three different multiplicities of infection of ZIKV were used to develop and compare this novel method to the standard confluent cell monolayer method. In addition, we preliminary validated the cell suspension method using well-characterized ZIKV positive and negative clinical samples. The standard confluent cell monolayer method was used as the reference method, and viral isolation was confirmed by a ZIKV-specific RT-PCR. The sensitivity and its 95% confidence intervals for the cell suspension method were estimated. Also, a technical comparison of the cell suspension method against the cell monolayer method was performed.

RESULTS.

Our findings suggested that both the viral load and replication of ZIKV were comparable between both monolayer- and suspension-infection methods. Although both methods were suitable for culturing and isolating ZIKV, the cell suspension method was easier, cheaper, and quicker as well as a sensitive isolation technique. The cell suspension method was significantly more sensitive in detecting Zika in inconclusive cases by RT-PCR, with a fourfold increase compared to the confluent cell monolayer method.

CONCLUSION.

The cell suspension method has the potential to be an effective method for cultivating and isolating ZIKV and its application is potentially useful in both research and clinical settings.

Detection of Zika Virus in Oropharyngeal Swabs from Patients with Acute Febrile Illness

The isolation of Zika virus (ZIKV) from serum of suspected human cases for diagnostic purposes can be challenging due to infrastructure constraints of laboratory testing technology. Therefore, as an alternative method, the objective of this study was to evaluate a random sample of oropharyngeal swabs for the diagnosis of ZIKV infection among patients with symptoms of arboviral and respiratory illness. The results revealed that ZIKV RNA could be detected by a reverse transcriptase polymerase chain reaction (RT-PCR) assay and isolated from oropharyngeal swabs from five of 38 samples, but serum samples from the same patients were negative for ZIKV by a variety of laboratory diagnostic approaches including RT-PCR and viral isolation followed by immunofluorescence assays. The findings suggested that the molecular detection and isolation of ZIKV in oropharyngeal swab warrants further study for consideration as an improved diagnostic procedure.

In vitro antimicrobial activity of Bixa orellana L . Leaves extract against anaerobic bacteria associated to bacterial vaginosis and Lactobacillus spp

OBJECTIVE.

Motivation for the study: bacterial vaginosis is a bacterial infection that frequently affects women of reproductive age. The treatment is based on synthetic antimicrobials. Bixa orellana L. possesses antimicrobial properties and could represent a potential non-synthetic therapeutic alternative. Main findings: in vitro results suggest that, methanolic extract of Bixa orellana L. leaves possesses potential antimicrobial properties against bacteria associated to bacterial vaginosis. Implications: to identify new sources with therapeutic potential, and to promote research, discovery, and characterization of non-synthetic antimicrobials. To describe the in vitro antimicrobial activity of the methanolic extract of Bixa orellana L. leaves against anaerobic bacteria associated to bacterial vaginosis and Lactobacillus spp.

MATERIALS AND METHODS.

Eight ATCC reference strains; Gardnerella vaginalis, Prevotella bivia, Peptococcus niger, Peptostreptococcus anaerobius, Mobiluncus curtisii, Atopobium vaginae, Veillonella parvula, and Lactobacillus crispatus, and twenty-two clinical isolates; eleven Gardnerella vaginalis and eleven Lactobacillus strains, were included in the study. The antimicrobial susceptibility was determined by the agar diffusion method. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined by using agar dilution and a modified dilution plating method, respectively.

RESULTS.

All ATCC reference strains showed high levels of susceptibility to the extract, except P. vibia, V. parvula and L. crispatus. Interestingly, all G. vaginalis clinical isolates and the G. vaginalis ATTC strain were the most susceptible to the extract, given their low MIC (1.0 - 2.0 mg/mL) and MBC (1.0 - 4.0 mg/mL) values, whereas, the Lactobacillus spp. clinical isolates and the L. crispatus ATCC strain were the least susceptible bacteria given their high MIC (32.0 mg/mL) and MBC (≥ 32.0 mg/mL) values.

CONCLUSIONS.

In vitro experiments suggest that the extract possesses selective antimicrobial properties given its high activity against bacterial vaginosis-associated anaerobic bacteria and low activity against Lactobacillus species.

Molecular Characterization by Multilocus Sequence Typing and Diversity Analysis of Rickettsia asembonensis in Peru

Despite several reports worldwide documenting the presence of Rickettsia asembonensis in samples derived from ectoparasites, animals and more recently humans, genomic information of these specimens remains scarce, and when available, is usually limited to small genomic fragments of limited value. We generated complete sequences for two conserved (17-kDa antigen gene and gltA) and three variable (sca4, ompB and ompA) genes in five R. asembonensis DNA samples detected in cat and dog fleas in Peru. Complete gene sequences were used to conduct multi-locus sequence typing and phylogenetic analyses to assess diversity and infer relationships among strains and other reference sequences. The 17-kDa antigen gene was highly conserved across Rickettsia species. Of the variable genes ompB was the most variable, but this diversity was not captured through phylogenetics alone even when efforts were made to maximize potential diversity in terms of flea species, animal host and location. Through a combination of de novo and reference-based genome assembly we identified a 75 bp insertion in ompA that encodes a 25 aa repetitive motif found in other Rickettsia species, but not present in the original prototype strain from Kenya. R. asembonensis has only recently been shown to be a bona-fide human pathogen. As such, and compounded by a lack of available genomic information, it remains understudied. Our work directly addresses the lack of genomic information available worldwide for the study of these novel Rickettsia species and specifically contributes to our understanding of the diversity and molecular epidemiology of R. asembonensis in Peru.

Climatic Variability and Human Leptospirosis Cases in Cartagena, Colombia: A 10-Year Ecological Study

Leptospirosis is an acute febrile disease that mainly affects developing countries with tropical climates. The complexity and magnitude of this disease is attributed to socioeconomic, climatic, and environmental conditions. In this study, in a 10-year period from 2008 to 2017, the relationship between human leptospirosis cases and climatic factors in Cartagena de Indias, Colombia were evaluated. Monthly leptospirosis cases, climatic variables, and macroclimatic phenomena (El Niño and La Niña) were obtained from public datasets. Local climatic factors included temperature (maximum, average, and minimum), relative humidity, precipitation, and the number of precipitation days. Time series graphs were drawn and correlations between cases of leptospirosis and climatic variables considering lags from 0 to 10 months were examined. A total of 360 cases of leptospirosis were reported in Cartagena during the study period, of which 192 (53.3%) were systematically notified between October and December. Several correlations were detected between the number of cases, local climatic variables, and macroclimatic phenomena. Mainly, the increase of cases correlated with increased precipitation and humidity during the La Niña periods. Herein, seasonal patterns and correlations suggest that the climate in Cartagena could favor the incidence of leptospirosis. Our findings suggest that prevention and control of human leptospirosis in Cartagena should be promoted and strengthened, especially in the last quarter of the year.

Climatic factors and the incidence of dengue in Cartagena, Colombian Caribbean Region

Background:

The influence of climate on the epidemiology of dengue has scarcely been studied in Cartagena.

Methods:

The relationship between dengue cases and climatic and macroclimatic factors was explored using an ecological design and bivariate and time-series analyses during lag and non-lag months. Data from 2008-2017 was obtained from the national surveillance system and meteorological stations.

Results:

Cases correlated only with climatic variables during lag and non-lag months. Decreases in precipitation and humidity and increases in temperature were correlated with an increase in cases.

Conclusions:

Our findings provide useful information for establishing and strengthening dengue prevention and control strategies.

High titers of anti-A1 and anti-B antibodies among Peruvian group O platelet donors

Critical antibody titers have been described as factors associated with hemolysis in ABO plasma-incompatible platelet (PLT) transfusions. This study was carried out to describe the frequency of high-titers anti-A and antiB IgM and IgG antibodies in group O apheresis platelet donors, and to explore differences according to the donor characteristics. A cross-sectional study was carried out at the Blood Bank of a National Hospital in Peru from January to March 2019. IgM and IgG antibodies against A1 and B antigens were quantified in 339 platelet donors using the direct hemagglutination technique and the solid-phase adherence technique, respectively. For analysis purposes, two cut-off points; ≥128 and ≥64, were used to define a critical titer for IgM due to a lack of consensus. An IgG titer of ≥256 was also defined as critical. Of the donors, 22.1 % had critical IgM titers when the cut-off point was defined as ≥128. However, when the IgM cut-off was ≥64, the frequency of platelet donors with critical titers increased to 54.0 %. The frequency of donors with critical IgG titers was 23.5 %. Higher IgG titers were associated with female donors while higher IgM titers were negative associated with age. One in two or three platelet donors, depending on the cutoff point used to define a critical IgM titer, had at least one critical titer of anti-A or anti-B antibodies. Early identification of platelet donors with critical antibody titers could prevent passive transfusion of ABO antibodies to non-isogroup recipients.

Molecular Characterization of Bartonella Species Discovered in Ectoparasites Collected from Domestic Animals, Cuzco, Peru

Rickettsiae and bartonellae are Gram-negative bacteria that can cause zoonotic and human diseases and are vectored by hematophagous arthropods. In the Americas, rickettsioses and bartonelloses have reemerged as significant public health threats. Bartonella species have been identified as causing zoonotic infections responsible for a variety of clinical syndromes in humans and animals. The aim of this study was to investigate the distribution, prevalence, and molecular heterogeneity of Rickettsia spp. and Bartonella spp. among ectoparasites collected from domestic animals in 14 farming communities in the Andes Mountains of Cuzco, Peru. A total of 222 domestic animals representing 8 different species (sheep, donkeys, goats, cattle, pigs, llamas, guinea pigs, and horses) were sampled. Nine species of ectoparasites (n = 1,697) collected from 122 animals were identified resulting in 1,657 chewing lice, 39 ticks, and 1 flea. DNA was individually extracted from a random sample of 600 (35.4%) considering variability of ectoparasite species, hosts, and sample location elevation. All 600 samples were negative for rickettsial DNA by a genus-specific molecular assay. A subset of 173 (28.8%) samples were selected based on variability of arthropods species, host, and location for Bartonella testing. Ninety-one (52.6%) of these samples including Melophagus ovinus (90/110) and Bovicola bovis (1/7) were positive for Bartonella by a genus-specific molecular assay. Five Bartonella genes of seven DNA samples from M. ovinus were analyzed by the multilocus sequence typing for characterization. We identified five identical Bartonella melophagi specimens and two specimens with Bartonella species related to B. melophagi from the seven M. ovinus. The Bartonella agents detected were widely distributed and frequent in multiple studied locations.

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Fecal Contamination of Drinking Water Was Associated with Diarrheal Pathogen Carriage among Children Younger than 5 Years in Three Peruvian Rural Communities

Drinking water contamination is a frequent problem in developing countries and could be associated with bacterial pathogen carriage in feces. We evaluated the association between the risk of drinking water and bacterial carrier status in children younger than 5 years in a cross-sectional study conducted in 199 households from three Peruvian rural communities. Fecal samples from children were screened for pathogenic Aeromonas, Campylobacter, and Vibrio species, as well as for Enterobacteriaceae, including pathogenic Escherichia coli. The drinking water risk was determined using E. coli as an indicator of contamination. Nineteen (9.5%) children were colonized with pathogens and classified as carriers, all without diarrhea symptoms. Of 199 drinking water samples, 38 (19.1%) were classified as very high risk because of high fecal contamination (> 100 E. coli/100 mL). Shared-use water sources, daily washing of containers, and washing using only water were associated with higher prevalence of bacterial carriage, whereas there was no association between households reporting boiling and chlorination of water and carrier status. The prevalence of carriage in children exposed to very high-risk water was 2.82 (95% CI: 1.21-6.59) times the prevalence of those who consumed less contaminated water, adjusted by the water source and daily washing. Our results suggest that household drinking water plays an important role in the generation of carriers with diarrheal pathogens. Our findings also highlight the importance of interventions to ensure the safety of drinking water. Further studies are needed to validate the observed association and determine its significance with respect to diarrhea in the community.

Minority Gene Expression Profiling: Probing the Genetic Signatures of Pathogenesis Using Ribosome Profiling

Minority Gene Expression Profiling (MGEP) refers to a scenario where the expression profiles of specific genes of interest are concentrated in a small cellular pool that is embedded within a larger, non-expressive pool. An example of this is the analysis of disease-related genes within sub-populations of blood or biopsied tissues. These systems are characterized by low signal-to-noise ratios that make it difficult, if not impossible, to uncover the desired signatures of pathogenesis in the absence of lengthy, and often problematic, technical manipulations. We have adapted ribosome profiling (RP) workflows from the Illumina to the Ion Proton platform and used them to analyze signatures of pathogenesis in an MGEP model system consisting of human cells eliciting <3% productive dengue infection. We find that RP is powerful enough to identify relevant responses of differentially expressed genes, even in the presence of significant noise. We discuss how to deal with sources of unwanted variation, and propose ways to further improve this powerful approach to the study of pathogenic signatures within MGEP systems.

Seroprevalence and Risk Factors for Rickettsia and Leptospira Infection in Four Ecologically Distinct Regions of Peru

Rickettsia and Leptospira spp. are under-recognized causes of acute febrile disease worldwide. Rickettsia species are often placed into the spotted fever group rickettsiae (SFGR) and typhus group rickettsiae (TGR). We explored the antibody prevalence among humans for these two groups of rickettsiae in four regions of Peru (Lima, Cusco, Puerto Maldonado, and Tumbes) and for Leptospira spp. in Puerto Maldonado and Tumbes. We also assessed risk factors for seropositivity and collected serum samples and ectoparasites from peri-domestic animals from households in sites with high human seroprevalence. In total, we tested 2,165 human sera for antibodies (IgG) against SFGR and TGR by ELISA and for antibodies against Leptospira by a microscopic agglutination test. Overall, human antibody prevalence across the four sites was 10.6% for SFGR (ranging from 6.2% to 14.0%, highest in Tumbes) and 3.3% for TGR (ranging from 2.6% to 6.4%, highest in Puerto Maldonado). Factors associated with seroreactivity against SFGR were male gender, older age, contact with backyard birds, and working in agriculture or with livestock. However, exposure to any kind of animal within the household decreased the odds ratio by half. Age was the only variable associated with higher TGR seroprevalence. The prevalence of Leptospira was 11.3% in Puerto Maldonado and 5.8% in Tumbes, with a borderline association with keeping animals in the household. We tested animal sera for Leptospira and conducted polymerase chain reaction (PCR) to detect Rickettsia species among ectoparasites collected from domestic animals in 63 households of seropositive participants and controls. We did not find any association between animal infection and human serostatus.

Rickettsia asembonensis Characterization by Multilocus Sequence Typing of Complete Genes, Peru

While studying rickettsial infections in Peru, we detected Rickettsia asembonensis in fleas from domestic animals. We characterized 5 complete genomic regions (17kDa, gltA, ompA, ompB, and sca4) and conducted multilocus sequence typing and phylogenetic analyses. The molecular isolate from Peru is distinct from the original R. asembonensis strain from Kenya.

Multidrug-resistant bacteria isolated from cell phones in five intensive care units: Exploratory dispersion analysis

Introduction

Cell phones are susceptible to bacterial contamination. The aim of this study was to characterize the bacterial isolates and to explore their dispersion in five Intensive Care Units (ICUs) over the time.

Methods

We performed a secondary analysis of non-fermenting Gram-negative bacteria and Gram-positive cocci isolated from a 5-month observational cohort study developed among health care workers' cell phones in five ICUs. Cell phones were sampled using a swab every 15 days. Antimicrobial resistance was determined by the minimum inhibitory concentration method. We constructed resistance phenotypes to group the isolates according to species and antimicrobial resistance pattern to explore dispersion through time.

Results

A total of 35 P. aeruginosa, 16 Acinetobacter spp., 30 S. aureus and 26 Enterococcus spp. were isolated from 491 phone samples. Multidrug resistance was 2.9% for P. aeruginosa, 31.3% for Acinetobacter spp., 46.7% for S. aureus and 80.8% for Enterococcus spp. The resistance to methicillin in S. aureus and to vancomycin in Enterococcus spp. was 26.7% and 42.3%, respectively. We did not observe distribution patterns or clusters over the time for P. aeruginosa, Acinetobacter spp. and Enterococcus spp. isolates. All the S. aureus isolates grouped into eight phenotypes. Interestingly, we observed S. aureus isolates with the same phenotype in consecutive and separate sampling dates in the same cell phone.

Conclusion

Cell phones are contaminated with highly harmful bacteria and potentially can maintain them for prolonged periods of time. These devices could be considered as a potential source of nosocomial infections in ICUs.

Serologic Evidence of Scrub Typhus in the Peruvian Amazon

Using a large, passive, febrile surveillance program in Iquitos, Peru, we retrospectively tested human blood specimens for scrub typhus group orientiae by ELISA, immunofluorescence assay, and PCR. Of 1,124 participants, 60 (5.3%) were seropositive, and 1 showed evidence of recent active infection. Our serologic data indicate that scrub typhus is present in the Peruvian Amazon.

Extended-spectrum β-lactamase-producing Enterobacteriaceae in cell phones of health care workers from Peruvian pediatric and neonatal intensive care units

BACKGROUND

Health care workers (HCWs) use their mobile phones during working hours or medical care. There is evidence that the instruments are colonized with pathogenic microorganisms. Here, we describe levels of Enterobacteriaceae contamination (EC) in cell phones and the risk factors associated with EC in Peruvian intensive care units (ICUs).

METHODS

This was a 5-month cohort study among 114 HCWs of 3 pediatric and 2 neonatology ICUs from 3 Peruvian hospitals. A baseline survey collected data on risk factors associated with EC. Swabs were collected from HCWs' phones every other week.

RESULTS

Three-quarters of HCWs never decontaminated their phones, and 47% reported using the phones in the ICU >5 times while working. EC was frequent across samplings and sites and was substantially higher in subjects with longer follow-up. Potential risk factors identified did not have strong associations with positive samples (relative risk, 0.7-1.5), regardless of significance. Half of the phones were colonized with an Enterobacteriaceae at least once during the 4 samplings attained on average during the study period. Half of the isolates were multidrug resistant (MDR), and 33% were extended-spectrum β-lactamase producers.

CONCLUSIONS

EC on HCWs' phones was frequent and apparently randomly distributed through the hospitals without clear clustering or strongly associated risk factors for having a positive sample. Based on the level of EC, phones may be considered as potential bacterial reservoirs of MDR and ESBL bacteria.

Rickettsial Disease in the Peruvian Amazon Basin

Using a large, passive, clinic-based surveillance program in Iquitos, Peru, we characterized the prevalence of rickettsial infections among undifferentiated febrile cases and obtained evidence of pathogen transmission in potential domestic reservoir contacts and their ectoparasites. Blood specimens from humans and animals were assayed for spotted fever group rickettsiae (SFGR) and typhus group rickettsiae (TGR) by ELISA and/or PCR; ectoparasites were screened by PCR. Logistic regression was used to determine associations between patient history, demographic characteristics of participants and symptoms, clinical findings and outcome of rickettsial infection. Of the 2,054 enrolled participants, almost 2% showed evidence of seroconversion or a 4-fold rise in antibody titers specific for rickettsiae between acute and convalescent blood samples. Of 190 fleas (Ctenocephalides felis) and 60 ticks (Rhipicephalus sanguineus) tested, 185 (97.4%) and 3 (5%), respectively, were positive for Rickettsia spp. Candidatus Rickettsia asemboensis was identified in 100% and 33% of the fleas and ticks tested, respectively. Collectively, our serologic data indicates that human pathogenic SFGR are present in the Peruvian Amazon and pose a significant risk of infection to individuals exposed to wild, domestic and peri-domestic animals and their ectoparasites.

Rickettsial infection remains relatively unexplored in South America compared to other regions of the world. For most regions of Peru (including the Amazon Basin), nothing more than broad serological characterization is available about circulating rickettsiae. Even less is known about the animal reservoirs and insect vectors involved in disease transmission. With this study we aimed to better characterize the circulating species of Rickettsia in humans in the Amazon Basin, as well as investigate their domestic animal reservoir and arthropod vectors. Out of 2054 fever patients enrolled we identified 38 individuals with serologic evidence for acute rickettsial infection. Their homes were visited in order to draw blood samples and collect ectoparasites from their domestic animals. Serology and molecular methods were used to test the animal blood samples as well as the ectoparasites. The information collected contributes to the understanding of the transmission dynamics of rickettsial diseases in Iquitos and leads to a better understanding of the exposure risk to rickettsial infection and it will guide approaches for prevention.

Full Genomic Characterization of a Saffold Virus Isolated in Peru

While studying respiratory infections of unknown etiology we detected Saffold virus in an oropharyngeal swab collected from a two-year-old female suffering from diarrhea and respiratory illness. The full viral genome recovered by deep sequencing showed 98% identity to a previously described Saffold strain isolated in Japan. Phylogenetic analysis confirmed the Peruvian Saffold strain belongs to genotype 3 and is most closely related to strains that have circulated in Asia. This is the first documented case report of Saffold virus in Peru and the only complete genomic characterization of a Saffold-3 isolate from the Americas.

[Mechanical fragmentation and intrapulmonary fibrinolysis in the treatment of massive pulmonary embolism hemodynamic repercussions]

OBJECTIVE

To evaluate the efficacy and safety of mechanical fragmentation associated with intrapulmonary thrombolysis to treat massive pulmonary thromboembolism (PTE) with altered hemodynamics.

MATERIAL AND METHOD

Fifty-one patients with a diagnosis of acute PTE were enrolled, the criteria being a Miller index over 0.50 and mean pressure of 30 mmHg in the principal superior pulmonary artery. The initial clinical pictures included shock (19 patients), syncope (6) and severe dyspnea at rest (26). Oxygen saturation measured by pulse oxymetry was 71.4%. Mean pulmonary artery pressure was 46.1 mmHg. The main thromboembolisms were fragmented, with one bolus of a fibrinolytic agent administered during the fragmentation procedure. An infusion of the fibrinolytic agent was administered through a catheter. Monitoring included clinical assessment, pulmonary scintigraphy and echocardiography.

RESULTS

After fragmentation and administration of the bolus dose of the fibrinolytic agent, improvement was observed in 49 patients (97.2%). Mean pressure after mechanical and pharmacological treatment was 24.1 mmHg. Technical success was achieved in 100% of the patients.

CONCLUSION

The results attest to the efficacy and safety of mechanical fragmentation and medical thrombolysis in treating massive PTE affecting hemodynamics, leading to clinical improvement and lowered pulmonary artery pressure.

Massive pulmonary embolism: treatment with the hydrolyser thrombectomy catheter

PURPOSE

To assess the efficacy of clot removal with use of the Hydrolyser thrombectomy catheter in acute massive pulmonary embolism (PE).

MATERIALS AND METHODS

Eleven patients (eight women, three men) with a mean age of 61 (range, 37-79) years with acute massive PE underwent percutaneous mechanical thrombectomy (PMT) with use of the Hydrolyser. In four patients with no contraindication, fibrinolysis was performed with use of urokinase at low doses after thrombectomy.

RESULTS

Ten patients (90.91%) recovered from massive PE and were discharged within 11 days. The Urokinase Pulmonary Embolism Trial angiographic severity indexes (mean +/- SD) were 14.7 +/- 2.6 and 7.5 +/- 2.7, respectively, before and after thrombectomy (P < .001). Partial arterial pressures of O2 increased from 72.8 mm Hg +/- 16.4 to 93.5 mm Hg +/- 5.6 (P < .005). Pulmonary artery pressure decreased from 45.5 mm Hg +/- 14.2 to 29.5 mm Hg +/- 13.6 after thrombectomy (P < .0001). Calculated by semiquantitative computed analysis, PMT with use of the Hydrolyser removed 74.06% of thrombus +/- 13.46%. One patient developed self-limited hemoptysis immediately after thrombectomy. One patient died during the procedure secondary to PE.

CONCLUSION

PMT with use of the Hydrolyser is effective and safe in massive PE, resulting in improved hemodynamics and blood oxygenation and decreased pulmonary artery pressure. It offers an alternative to fibrinolysis and surgical thrombectomy.

[Colorectal neoplasms. Treatment of obstruction with autoexpanding metal stents]

BACKGROUND

Expandable metal stents can be used as a palliative or pre surgical method to decompress obstructing colonic carcinomas.

AIM

To assess the effectiveness of these stents in the treatment of obstructive colonic carcinoma.

PATIENTS AND METHODS

Expandable metal stents were placed in nine patients with the diagnosis of colorectal carcinoma and with clinical and radiographic signs of intestinal obstruction. Stents were placed under fluoroscopic guidance in nine patients and with endoscopic help in 2. The indications were palliative treatment in 7 and pre surgical decompression in 2 patients.

RESULTS

Stent placement was successful in all patients. One patient presented a self limited rectal bleeding after the procedure. Obstruction was relieved in less than 24 hours after the procedure.

CONCLUSION

Expandable metal stent placement is an effective means of relieving intestinal obstruction caused by colorectal carcinoma.

External iliac vein thrombosis after renal transplantation: treatment by thrombolysis and stent placement: a case report

We present a patient with iliac vein stenosis and thrombosis, which occurred 2 weeks after renal transplantation and were secondary to a perivascular hematic collection. The vein stenosis was identified by color Doppler ultrasonography and venography. Computed tomography demonstrated a perivascular collection. One week later, control venography identified iliac vein thrombosis. The patient underwent pharmacological thrombolysis with local infusion of urokinase for 4 hr, percutaneous transluminal angioplasty, and percutaneous installation of a metallic stent (Wallstent), with immediate favorable results. The patient remains in stable condition at 2 years after the procedure.

Mechanical fragmentation and pharmacologic thrombolysis in massive pulmonary embolism

PURPOSE

To evaluate the usefulness of mechanical fragmentation associated with intrapulmonary thrombolysis in acute massive pulmonary embolism (PE).

PATIENTS AND METHODS

Sixteen cases of massive PE treated with mechanical fragmentation associated with pharmacologic thrombolysis were retrospectively studied. Severity of PE was assessed with the angiographic index according to the Urokinase Pulmonary Embolism Trial (maximum value of 18; score according to whether obstruction was central or peripheral, complete or partial). Mechanical fragmentation of the emboli was performed with angiographic catheters and angioplasty balloons. Urokinase was infused directly into the thrombus during the course of 8-24 hours. The effect of therapy was measured with direct pulmonary artery pressure (PAP) and blood O2 values.

RESULTS

Pre- and postinfusion angiographic index mean values (+/- standard deviation) were 13.7 +/- 1.4 and 6.1 +/- 2.2 (P < .0001). Mean pre- and postinfusion PAPs were 48.2 +/- 13.4 and 18.5 +/- 7.2 mm Hg (P < .0001). PaO2 increased from 60.1 +/- 12.1 to 88.7 +/- 23.4 mm Hg (P = .01). Fourteen patients (87.5%) completely recovered. One patient died during treatment despite improvement in PAP and PaO2 parameters. There were no major hemorrhagic complications.

CONCLUSIONS

The data support the efficacy of mechanical fragmentation associated with pharmacologic thrombolysis in the treatment of acute massive PE, resulting in improved hemodynamics and-blood oxygenation and in decreased PAP, with low morbidity.

[Percutaneous biliary endoprostheses. Clinical experience of 6 years]

The aim of this study was to assess the effectiveness and long term permeability of percutaneous biliary endoprostheses. Seventy three patients with biliary tract obstruction due to a primary malignant tumor (n = 60), lymph node metastases at the porta hepatis (n = 10) and benign stenosis of a biliary-enteric anastomosis (n = 3), were treated between 1985 and 1990. Plastic prostheses were installed in 63 patients and metallic in 10. The procedure had a 30% incidence of complications. Thirty three percent of the prostheses remained patent until patient's death. In 15 and 40% of patients, signs of prosthesis obstruction were observed three and six months after installation respectively, bearing in mind a mean survival of 24 weeks. In 90% of patients there was a clinical and laboratory improvement. Mortality was 30% at 30 days in the group of patients with malignant diseases. It is concluded that the installation of percutaneous biliary endoprostheses is a relatively safe and well tolerated procedure, with a low incidence of complications or mortality and that allows an effective biliary decompression.

[Syncope: recurrence and prognosis during 2 years]

We followed up 143 patients that had been admitted to intensive care units of a general hospital with syncope. 127 patients (89%) remained in follow up for a mean of 24 months (range 3 to 54 months). There were 70 men and 57 women and the mean age was 71.5 years. Recurrences were observed in 21 patients (17%) and were similar for patients whose syncope had a cardiovascular origin (10%), non cardiovascular origin (25%) or an undetermined cause (18%). Mortality from cardiac or vascular causes was 20% in the cardiovascular origin group, and 5 and 4.2% in the other groups, respectively (p less than 0.005). Recurrence did not influence mortality. A history of hypertension, cerebrovascular accidents and ventricular arrhythmias was associated to higher mortality risk (p less than 0.05).

[Syncope: general characteristics and its relation to age]

We retrospectively analyzed the clinical data of 146 patients admitted to a general hospital with the diagnosis of syncope. A definite or highly likely cause was identified in 91 patients (62%). These were of cardiovascular origin in 78%: conduction defects (31), sinus node disease (9), obstructive causes (8), ventricular arrhythmia (8), ischemia (5) and miscellaneous (14). A non cardiovascular origin was present in 22% of patients: intoxication (7), hysteria (5), hypoxemia (3), vasovagal (2), gastrointestinal bleeding (2) and 2 others. The final diagnosis in patients with a known cause was established by the history and physical examination in 16, the ECG in 42, Holter 9, ECG monitoring in ICU 8 and echocardiogram 6. No difference in the distribution of causes was present between patients below or above 65 years of age. In hospital mortality was 2%.