COVID-19 seroprevalence in military police force, Southern Brazil.

BACKGROUND: Limited data is available regarding the frequency of COVID-19 in populations that are highly exposed to SARS-CoV-2. In this cross-section study we evaluated COVID-19 seroprevalence in military police forces of 10 major cities in Rio Grande do Sul, South of Brazil. METHODS: Sampling was randomly performed in clusters, in respect to the number of professionals at service per city and military unit. Research subjects were evaluated on July 23, 2020 (first wave peak in Brazil). Clinical information was obtained, and venous blood was taken for ELISA testing (IgA, and IgG antibodies). Sample size consisted of 1,592 military workers (33.6% of study population). They were mostly man (81.2%) and young (median 34 years-old). Most had been asymptomatic (75.3%) during pandemic, and 27.5% reported close contact with COVID-19 cases (after a median time of 21 days). Antibodies were detected in 3.3% of the participants, mostly IgA (2.7%), and IgG (1.7%). After 3 weeks, 66.7% of IgA and IgG results turned negative, in addition to 78.3% and 100% of borderline IgA and IgG results, respectively. CONCLUSION: The seroprevalence of COVID-19 amongst military police was at least 3.4 higher than the findings of other studies performed in the general population, in the same cities and dates. Most detectable antibodies were of IgA class, which implies recent exposure. Asymptomatic people were more prone to have negative antibody titters in the second run.

Polymyxin NP tests (from colonies and directly from blood cultures): accurate and rapid methodologies to detect polymyxin B susceptibility among Enterobacterales.

Detection of polymyxins susceptibility is challenging. We aimed to evaluate Rapid Polymyxin NP from colonies (NP-colony) and directly from positive blood bottles (NP-bottle), using polymyxin B instead of colistin among Enterobacterales. Both had similar and acceptable accuracy. This is the first study performing NP-bottle using polymyxin B instead of colistin.

Is the Frequency of Candidemia Increasing in COVID-19 Patients Receiving Corticosteroids?

Corticosteroids have potent anti-inflammatory and immunosuppressive effects. Recently, these medications have gained importance in the treatment of severe COVID-19. Here we present data demonstrating a marked (10-fold) increase in frequency of candidemia in hospitalized patients with COVID-19 receiving corticosteroids in Brazil. Overall mortality was 72.7%, despite antifungal therapy. Physicians should be aware of the potential risk for candidemia among severely ill COVID-19 patients receiving high-doses of corticosteroids.

Polymyxin B broth disk elution: a feasible and accurate methodology to determine polymyxin B susceptibility in Enterobacterales.

Determination of polymyxins susceptibility by clinical laboratories is a nightmare, mainly because of physicochemical properties of the drug. Elution tests have already been proposed for colistin, but not for polymyxin B. We aimed to evaluate accuracy of Polymyxin B broth disk elution (PBDE) to determine the susceptibility to this drug. We evaluated 196 Enterobacterales (45.9% polymyxin B-resistant). PBDE was done in 15-mL cation-adjusted Mueller-Hinton broth where one polymyxin B disk (300 U) was eluted (2 µg/mL). BMD was performed as reference method. Categorical Agreement (CA), Major Error (ME) and Very Major Error (VME) were 99.5%, 0% and 1.11% (one false-negative K. pneumoniae MIC 4 µg/mL), respectively. As some institutions preferably use polymyxin B over colistin and in some countries colistin are not commercially available, to specifically evaluate polymyxin B is important. PBDE proved to be a cheap and easy to perform methodology to evaluate susceptibility to polymyxin B among Enterobacterales.