Endogenous origin of Pseudomonas aeruginosa infecting hospitalized patients in Ecuador.

Recent evidence suggests that Pseudomonas aeruginosa, a bacterium that has the ability to cause deadly infections in hospitalized patients, could originate in the patient's own flora. We employed the Oxford Nanopore platform to obtain whole genome sequences (WGS) from clinical and rectal screen P. aeruginosa strains belonging to 15 patients from two hospitals. Our study found evidence that clinical and rectal isolates were clonal, with some evidence suggesting that the infecting strain was present in the patient's intestine at the time of admission, ruling out hospital acquisition. The use of WGS analysis is crucial to detect alternative sources of P. aeruginosa to develop new preventive measures against these serious infections.

Adapting for the COVID-19 pandemic in Ecuador, a characterization of hospital strategies and patients.

The World Health Organization (WHO) declared coronavirus disease-2019 (COVID-19) a global pandemic on 11 March 2020. In Ecuador, the first case of COVID-19 was recorded on 29 February 2020. Despite efforts to control its spread, SARS-CoV-2 overran the Ecuadorian public health system, which became one of the most affected in Latin America on 24 April 2020. The Hospital General del Sur de Quito (HGSQ) had to transition from a general to a specific COVID-19 health center in a short period of time to fulfill the health demand from patients with respiratory afflictions. Here, we summarized the implementations applied in the HGSQ to become a COVID-19 exclusive hospital, including the rearrangement of hospital rooms and a triage strategy based on a severity score calculated through an artificial intelligence (AI)-assisted chest computed tomography (CT). Moreover, we present clinical, epidemiological, and laboratory data from 75 laboratory tested COVID-19 patients, which represent the first outbreak of Quito city. The majority of patients were male with a median age of 50 years. We found differences in laboratory parameters between intensive care unit (ICU) and non-ICU cases considering C-reactive protein, lactate dehydrogenase, and lymphocytes. Sensitivity and specificity of the AI-assisted chest CT were 21.4% and 66.7%, respectively, when considering a score >70%; regardless, this system became a cornerstone of hospital triage due to the lack of RT-PCR testing and timely results. If health workers act as vectors of SARS-CoV-2 at their domiciles, they can seed outbreaks that might put 1,879,047 people at risk of infection within 15 km around the hospital. Despite our limited sample size, the information presented can be used as a local example that might aid future responses in low and middle-income countries facing respiratory transmitted epidemics.

Cycle Threshold Values in the Context of Multiple RT-PCR Testing for SARS-CoV-2.

PURPOSE: Discharge or follow up of confirmed coronavirus disease 2019 (COVID-19) cases depend on accurate interpretation of RT-PCR. Currently, positive/negative interpretations are based on amplification instead of quantification of cycle threshold (Ct) values, which could be used as proxies of patient infectiousness. Here, we measured Ct values in hospitalized confirmed COVID-19 patients at different times and its implications in diagnosis and follow up. PATIENTS AND METHODS: Observational study between March 17th-May 12th, 2020 using multiple RT-PCR testing. A cohort of 118 Hispanic hospitalized patients with confirmed COVID-19 diagnosis in a reference hospital in Quito, Ecuador. Multiple RT-PCR tests were performed using deep nasal swab samples and the assessment of SARS-CoV-2 genes N, RdRP, and E. RESULTS: Patients' median age was of 49 years (range: 24-91) with a male majority (62.7%). We found increasing levels of Ct values in time, with a mean Ct value of 29.13 (n = 61, standard deviation (sd) = 5.55) for the first test and 34.38 (n = 60, sd = 4), 35.52 (n = 20, sd = 2.85), and 36.12 (n = 6, sd = 3.28), for the second, third, and fourth tests, respectively. Time to RT-PCR lack of amplification for all tests was of 34 days while time to RT-PCR Ct values >33 was of 30 days. CONCLUSION: Cycle thresholds can potentially be used to improve diagnosis, management and control. We found that turnover time for negativity can be large for hospitalized patients and that 11% cases persisted with infectious Ct values for more time than the current isolation recommendations.

Genome sequencing of the first SARS-CoV-2 reported from patients with COVID-19 in Ecuador.

SARS-CoV-2, the etiological agent of COVID-19 was first described in Wuhan in December 2019 and has now spread globally. Ecuador was the second country in South America to report confirmed cases. The first case reported in Quito, the capital city of Ecuador, was a tourist who came from the Netherlands and presented symptoms on March 10th, 2020 (index case). In this work we used the MinION platform (Oxford Nanopore Technologies) to sequence the metagenome of the bronchoalveolar lavage (BAL) from this case reported, and subsequently we sequenced the whole genome of the index case and other three patients using the ARTIC network protocols. Our data from the metagenomic approach confirmed the presence of SARS-CoV-2 coexisting with pathogenic bacteria suggesting coinfection. Relevant bacteria found in the BAL metagenome were Streptococcus pneumoniae, Mycobacterium tuberculosis, Staphylococcus aureus and Chlamydia spp. Lineage assignment of the four whole genomes revealed three different origins. The variant HEE-01 was imported from the Netherlands and was assigned to B lineage, HGSQ-USFQ-018, belongs to the B.1 lineage showing nine nucleotide differences with the reference strain and grouped with sequences from the United Kingdom, and HGSQ-USFQ-007 and HGSQ-USFQ-010 belong to the B lineage and grouped with sequences from Scotland. All genomes show mutations in their genomes compared to the reference strain, which could be important to understand the virulence, severity and transmissibility of the virus. Our findings also suggest that there were at least three independent introductions of SARS-CoV-2 to Ecuador.