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Rationale: We developed a standardized method, possible poor treatment response (PPTR), to help ascertain efficacy endpoints in Study S31/A5349 (NCT02410772), an open-label trial comparing two 4-month rifapentine-based regimens with a standard 6-month regimen for the treatment of pulmonary tuberculosis (TB). Objectives: We describe the use of the PPTR process and evaluate whether the goals of minimizing bias in efficacy endpoint assessment and attainment of relevant data to determine outcomes for all participants were achieved. Methods: A PPTR event was defined as the occurrence of one or more prespecified triggers. Each PPTR required initiation of a standardized evaluation process that included obtaining multiple sputum samples for microbiology. Measurements and Main Results: Among 2,343 participants with culture-confirmed drug-susceptible TB, 454 individuals (19.4%) had a total of 534 individual PPTR events, of which 76.6% were microbiological (positive smear or culture at or after 17 wk). At least one PPTR event was experienced by 92.4% (133 of 144) of participants with TB-related unfavorable outcome and between 13.8% and 14.7% of participants with favorable and not-assessable outcomes. A total of 75% of participants with TB-related unfavorable outcomes had microbiological confirmation of failure to achieve a disease-free cure. Conclusions: Standardized methodologies, such as our PPTR approach, could facilitate unbiased efficacy outcome determinations, improve discrimination between outcomes that are related and unrelated to regimen efficacy, and enhance the ability to conduct pooled analyses of contemporary trials.
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Tuberculose Pulmonar , Tuberculose , Humanos , Antituberculosos/uso terapêutico , Tuberculose/tratamento farmacológico , Tuberculose Pulmonar/tratamento farmacológico , Tuberculose Pulmonar/microbiologiaRESUMO
CONTEXT: Health departments (HDs) work on the front lines to ensure the health of their communities, providing a unique perspective to public health response activities. Say Yes! COVID Test (SYCT) is a US federally funded program providing free COVID-19 self-tests to communities with high COVID-19 transmission, low vaccination rates, and high social vulnerability. The collaboration with 9 HDs was key for the program distribution of 5.8 million COVID-19 self-tests between March 31 and November 30, 2021. OBJECTIVE: The objective of this study was to gather qualitative in-depth information on the experiences of HDs with the SYCT program to better understand the successes and barriers to implementing community-focused self-testing programs. DESIGN: Key informant (KI) interviews. SETTING: Online interviews conducted between November and December 2021. PARTICIPANTS: Sixteen program leads representing 9 HDs were purposefully sampled as KIs. KIs completed 60-minute structured interviews conducted by one trained facilitator and recorded. MAIN OUTCOME MEASURES: Key themes and lessons learned were identified using grounded theory. RESULTS: Based on perceptions of KIs, HDs that maximized community partnerships for test distribution were more certain that populations at a higher risk for COVID-19 were reached. Where the HD relied predominantly on direct-to-consumer distribution, KIs were less certain that communities at higher risk were served. Privacy and anonymity in testing were themes linked to higher perceived community acceptance. KIs reported that self-test demand and distribution levels increased during higher COVID-19 transmission levels. CONCLUSION: HDs that build bridges and engage with community partners and trusted leaders are better prepared to identify and link high-risk populations with health services and resources. When collaborating with trusted community organizations, KIs perceived that the SYCT program overcame barriers such as mistrust of government intervention and desire for privacy and motivated community members to utilize this resource to protect themselves against COVID-19.
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COVID-19 , Humanos , COVID-19/diagnóstico , COVID-19/epidemiologia , COVID-19/prevenção & controle , Autoteste , Teste para COVID-19 , Teoria Fundamentada , Saúde PúblicaRESUMO
During July 2021, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) B.1.617.2 variant infections, including vaccine breakthrough infections, occurred after large public gatherings in Provincetown, Massachusetts, USA, prompting a multistate investigation. Public health departments identified primary and secondary cases by using coronavirus disease surveillance data, case investigations, and contact tracing. A primary case was defined as SARS-CoV-2 detected <14 days after travel to or residence in Provincetown during July 3-17. A secondary case was defined as SARS-CoV-2 detected <14 days after close contact with a person who had a primary case but without travel to or residence in Provincetown during July 3-August 10. We identified 1,098 primary cases and 30 secondary cases associated with 26 primary cases among fully and non-fully vaccinated persons. Large gatherings can have widespread effects on SARS-CoV-2 transmission, and fully vaccinated persons should take precautions, such as masking, to prevent SARS-CoV-2 transmission, particularly during substantial or high transmission.
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COVID-19 , Vacinas contra COVID-19 , Surtos de Doenças , Humanos , Massachusetts , SARS-CoV-2 , Estados Unidos/epidemiologiaRESUMO
On December 2, 2021, the Minnesota Department of Health (MDH) notified CDC of a COVID-19 case caused by sequence-confirmed SARS-CoV-2 B.1.1.529 (Omicron) variant in a Minnesota resident (patient A), the first such case identified in the state and one of the earliest identified in the United States. Patient A had attended a large indoor convention in New York, New York with approximately 53,000 attendees from 52 U.S jurisdictions and 30 foreign countries during November 19-21, 2021, and had close contact during 5 days with 29 fellow attendees. The convention required attendees to have received ≥1 COVID-19 vaccine dose and enforced mask-use while indoors. On November 22, these close contact attendees were directly and immediately notified by patient A of their exposure to SARS-CoV-2, and they sought testing over the next few days while quarantined or isolated. As part of the larger investigation into SARS-CoV-2 transmission at the convention, a subinvestigation was conducted during December by CDC, MDH, and respective state and local health departments to characterize the epidemiology of Omicron variant infection among this group of close contacts and determine the extent of secondary household transmission. Among 30 convention attendees that included patient A (the index patient) and the 29 other close contacts, 23 were interviewed, among whom all were fully vaccinated, including 11 (48%) who had received a booster dose; all 23 sought testing, and 16 (70%) received a positive SARS-CoV-2 test result. Fewer attendees who had received a booster dose before the convention received a positive test result (six of 11) compared with those who had not received a booster dose (10 of 12). The 16 attendees with positive test results had a total of 20 household contacts, 18 of whom sought testing after exposure; six received a positive test result for SARS-CoV-2. None of the persons with positive test results was hospitalized or died. There was limited convention-associated transmission identified outside of this cluster; the larger investigation included cases of both SARS-CoV-2 B.1.617.2 (Delta) and Omicron, and all Omicron cases were associated with this group (1). Data from this investigation reinforces the importance of COVID-19 booster doses in combination with early notification and other multicomponent prevention measures to limit transmission and prevent severe illness from Omicron and other SARS-CoV-2 variants.
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COVID-19/epidemiologia , Busca de Comunicante/métodos , Surtos de Doenças , Eventos de Massa , SARS-CoV-2 , Adulto , COVID-19/prevenção & controle , Vacinas contra COVID-19/administração & dosagem , Feminino , Humanos , Masculino , Cidade de Nova Iorque/epidemiologia , Rede Social , Estados Unidos/epidemiologiaRESUMO
High prevalences of HIV and other sexually transmitted infections (STIs) have been reported in the current global monkeypox outbreak, which has affected primarily gay, bisexual, and other men who have sex with men (MSM) (1-5). In previous monkeypox outbreaks in Nigeria, concurrent HIV infection was associated with poor monkeypox clinical outcomes (6,7). Monkeypox, HIV, and STI surveillance data from eight U.S. jurisdictions* were matched and analyzed to examine HIV and STI diagnoses among persons with monkeypox and assess differences in monkeypox clinical features according to HIV infection status. Among 1,969 persons with monkeypox during May 17-July 22, 2022, HIV prevalence was 38%, and 41% had received a diagnosis of one or more other reportable STIs in the preceding year. Among persons with monkeypox and diagnosed HIV infection, 94% had received HIV care in the preceding year, and 82% had an HIV viral load of <200 copies/mL, indicating HIV viral suppression. Compared with persons without HIV infection, a higher proportion of persons with HIV infection were hospitalized (8% versus 3%). Persons with HIV infection or STIs are disproportionately represented among persons with monkeypox. It is important that public health officials leverage systems for delivering HIV and STI care and prevention to reduce monkeypox incidence in this population. Consideration should be given to prioritizing persons with HIV infection and STIs for vaccination against monkeypox. HIV and STI screening and other recommended preventive care should be routinely offered to persons evaluated for monkeypox, with linkage to HIV care or HIV preexposure prophylaxis (PrEP) as appropriate.
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Infecções por HIV , Mpox , Profilaxia Pré-Exposição , Minorias Sexuais e de Gênero , Infecções Sexualmente Transmissíveis , Animais , Infecções por HIV/epidemiologia , Infecções por HIV/prevenção & controle , Homossexualidade Masculina , Humanos , Masculino , Mpox/epidemiologia , Infecções Sexualmente Transmissíveis/epidemiologia , Infecções Sexualmente Transmissíveis/prevenção & controleRESUMO
In January 2020, Santa Clara County, California, USA, began identifying laboratory-confirmed coronavirus disease among residents. County staff conducted case and contact investigations focused on households and collected detailed case demographic, occupation, exposure, and outcome information. We describe the first 200 test-positive cases during January 31-March 20, 2020, to inform future case and contact investigations. Probable infection sources included community transmission (104 cases), known close contact with a confirmed case-patient (66 cases), and travel (30 cases). Disease patterns across race and ethnicity, occupational, and household factors suggested multiple infection risk factors. Disproportionately high percentages of case-patients from racial and ethnic subgroups worked outside the home (Hispanic [86%] and Filipino [100%]); household transmission was more common among persons from Vietnam (53%). Even with the few initial cases, detailed case and contact investigations of household contacts capturing occupational and disaggregated race and ethnicity data helped identify at-risk groups and focused solutions for disease control.
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COVID-19 , Busca de Comunicante , California/epidemiologia , Humanos , SARS-CoV-2 , VietnãRESUMO
We assessed maternal and infant cytomegalovirus (CMV) infection in Colombia. Maternal serum was tested for CMV immunoglobulin G antibodies at a median of 10 (interquartile range: 8-12) weeks gestation (n = 1501). CMV DNA polymerase chain reaction was performed on infant urine to diagnose congenital (≤21 days of life) and postnatal (>21 days) infection. Maternal CMV seroprevalence was 98.1% (95% confidence interval [CI]: 97.5%-98.8%). Congenital CMV prevalence was 8.4 (95% CI: 3.9%-18.3%; 6/711) per 1000 live births. Among 472 infants without confirmed congenital CMV infection subsequently tested at age 6 months, 258 (54.7%, 95% CI: 50.2%-59.1%) had postnatal infection.
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Anticorpos Antivirais/sangue , Infecções por Citomegalovirus/epidemiologia , Infecções por Citomegalovirus/imunologia , Citomegalovirus/imunologia , Complicações Infecciosas na Gravidez/virologia , Adulto , Pré-Escolar , Colômbia/epidemiologia , Citomegalovirus/genética , Infecções por Citomegalovirus/congênito , Infecções por Citomegalovirus/urina , DNA Viral/urina , Feminino , Idade Gestacional , Humanos , Imunoglobulina G/sangue , Lactente , Mães , Gravidez , Complicações Infecciosas na Gravidez/epidemiologia , Complicações Infecciosas na Gravidez/imunologia , Saliva/virologia , Estudos SoroepidemiológicosRESUMO
Pregnant and recently pregnant women are at increased risk for severe illness and death from COVID-19 compared with women who are not pregnant or were not recently pregnant (1,2). CDC recommends COVID-19 vaccination for women who are pregnant, recently pregnant, trying to become pregnant, or might become pregnant in the future.*, This report describes 15 COVID-19-associated deaths after infection with SARS-CoV-2 (the virus that causes COVID-19) during pregnancy in Mississippi during March 1, 2020-October 6, 2021.
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COVID-19/mortalidade , Complicações Infecciosas na Gravidez/epidemiologia , Adulto , Vacinas contra COVID-19/administração & dosagem , Centers for Disease Control and Prevention, U.S. , Feminino , Humanos , Mississippi/epidemiologia , Guias de Prática Clínica como Assunto , Gravidez , Medição de Risco , Estados Unidos , Adulto JovemRESUMO
During February 2021, an opening event was held indoors at a rural Illinois bar that accommodates approximately 100 persons. The Illinois Department of Public Health (IDPH) and local health department staff members investigated a COVID-19 outbreak associated with this opening event. Overall, 46 COVID-19 cases were linked to the event, including cases in 26 patrons and three staff members who attended the opening event and 17 secondary cases. Four persons with cases had COVID-19-like symptoms on the same day they attended the event. Secondary cases included 12 cases in eight households with children, two on a school sports team, and three in a long-term care facility (LTCF). Transmission associated with the opening event resulted in one school closure affecting 650 children (9,100 lost person-days of school) and hospitalization of one LTCF resident with COVID-19. These findings demonstrate that opening up settings such as bars, where mask wearing and physical distancing are challenging, can increase the risk for community transmission of SARS-CoV-2, the virus that causes COVID-19. As community businesses begin to reopen, a multicomponent approach should be emphasized in settings such as bars to prevent transmission* (1). This includes enforcing consistent and correct mask use, maintaining ≥6 ft of physical distance between persons, reducing indoor bar occupancy, prioritizing outdoor seating, improving building ventilation, and promoting behaviors such as staying at home when ill, as well as implementing contact tracing in combination with isolation and quarantine when COVID-19 cases are diagnosed.
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COVID-19/transmissão , Infecções Comunitárias Adquiridas , Restaurantes/organização & administração , Adolescente , Adulto , Idoso , COVID-19/epidemiologia , Criança , Feminino , Humanos , Illinois/epidemiologia , Masculino , Pessoa de Meia-Idade , Adulto JovemRESUMO
Two near-identical clinical Streptococcus pyogenes isolates of emm subtype emm43.4 with a pbp2x missense mutation (T553K) were detected. Minimum inhibitory concentrations (MICs) for ampicillin and amoxicillin were 8-fold higher, and the MIC for cefotaxime was 3-fold higher than for near-isogenic control isolates, consistent with a first step in developing ß-lactam resistance.
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Streptococcus pyogenes , Resistência beta-Lactâmica , Antibacterianos/farmacologia , Humanos , Testes de Sensibilidade Microbiana , Mutação , Proteínas de Ligação às Penicilinas/genética , Streptococcus pyogenes/genética , Resistência beta-Lactâmica/genéticaRESUMO
BACKGROUND: Zika virus infection during pregnancy can cause serious birth defects, which include brain and eye abnormalities. The clinical importance of detection of Zika virus RNA in amniotic fluid is unknown. OBJECTIVE: The purpose of this study was to describe patterns of Zika virus RNA testing of amniotic fluid relative to other clinical specimens and to examine the association between Zika virus detection in amniotic fluid and Zika-associated birth defects. Our null hypothesis was that Zika virus detection in amniotic fluid was not associated with Zika-associated birth defects. STUDY DESIGN: We conducted a retrospective cohort analysis of women with amniotic fluid specimens submitted to Colombia's National Institute of Health as part of national Zika virus surveillance from January 2016 to January 2017. Specimens (maternal serum, amniotic fluid, cord blood, umbilical cord tissue, and placental tissue) were tested for the presence of Zika virus RNA with the use of a singleplex or multiplex real-time reverse transcriptase-polymerase chain reaction assay. Birth defect information was abstracted from maternal prenatal and infant birth records and reviewed by expert clinicians. Chi-square and Fisher's exact tests were used to compare the frequency of Zika-associated birth defects (defined as brain abnormalities [with or without microcephaly, but excluding neural tube defects and their associated findings] or eye abnormalities) by frequency of detection of Zika virus RNA in amniotic fluid. RESULTS: Our analysis included 128 women with amniotic fluid specimens. Seventy-five women (58%) had prenatally collected amniotic fluid; 42 women (33%) had amniotic fluid collected at delivery, and 11 women (9%) had missing collection dates. Ninety-one women had both amniotic fluid and other clinical specimens submitted for testing, which allowed for comparison across specimen types. Of those 91 women, 68 had evidence of Zika virus infection based on detection of Zika virus RNA in ≥1 specimen. Testing of amniotic fluid that was collected prenatally or at delivery identified 39 of these Zika virus infections (57%; 15 [22%] infections were identified only in amniotic fluid), and 29 infections (43%) were identified in other specimen types and not amniotic fluid. Among women who were included in the analysis, 89 had pregnancy outcome information available, which allowed for the assessment of the presence of Zika-associated birth defects. Zika-associated birth defects were significantly (P<.05) more common among pregnancies with Zika virus RNA detected in amniotic fluid specimens collected prenatally (19/32 specimens; 59%) than for those with no laboratory evidence of Zika virus infection in any specimen (6/23 specimens; 26%), but the proportion was similar in pregnancies with only Zika virus RNA detected in specimens other than amniotic fluid (10/23 specimens; 43%). Although Zika-associated birth defects were more common among women with any Zika virus RNA detected in amniotic fluid specimens (ie, collected prenatally or at delivery; 21/43 specimens; 49%) than those with no laboratory evidence of Zika virus infection (6/23 specimens; 26%), this comparison did not reach statistical significance (P=.07). CONCLUSION: Testing of amniotic fluid provided additional evidence for maternal diagnosis of Zika virus infection. Zika-associated birth defects were more common among women with Zika virus RNA that was detected in prenatal amniotic fluid specimens than women with no laboratory evidence of Zika virus infection, but similar to women with Zika virus RNA detected in other, nonamniotic fluid specimen types.
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Líquido Amniótico/virologia , Encéfalo/anormalidades , Anormalidades do Olho/epidemiologia , Microcefalia/epidemiologia , Complicações Infecciosas na Gravidez/metabolismo , RNA Viral/metabolismo , Infecção por Zika virus/metabolismo , Zika virus/genética , Adulto , Líquido Amniótico/metabolismo , Estudos de Coortes , Colômbia/epidemiologia , Feminino , Sangue Fetal/metabolismo , Sangue Fetal/virologia , Humanos , Recém-Nascido , Malformações do Sistema Nervoso/epidemiologia , Placenta/metabolismo , Placenta/virologia , Gravidez , Complicações Infecciosas na Gravidez/epidemiologia , Reação em Cadeia da Polimerase em Tempo Real , Estudos Retrospectivos , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Cordão Umbilical/metabolismo , Cordão Umbilical/virologia , Adulto Jovem , Infecção por Zika virus/epidemiologiaRESUMO
During January 1, 2020-August 10, 2020, an estimated 5 million cases of coronavirus disease 2019 (COVID-19) were reported in the United States.* Published state and national data indicate that persons of color might be more likely to become infected with SARS-CoV-2, the virus that causes COVID-19, experience more severe COVID-19-associated illness, including that requiring hospitalization, and have higher risk for death from COVID-19 (1-5). CDC examined county-level disparities in COVID-19 cases among underrepresented racial/ethnic groups in counties identified as hotspots, which are defined using algorithmic thresholds related to the number of new cases and the changes in incidence. Disparities were defined as difference of ≥5% between the proportion of cases and the proportion of the population or a ratio ≥1.5 for the proportion of cases to the proportion of the population for underrepresented racial/ethnic groups in each county. During June 5-18, 205 counties in 33 states were identified as hotspots; among these counties, race was reported for ≥50% of cumulative cases in 79 (38.5%) counties in 22 states; 96.2% of these counties had disparities in COVID-19 cases in one or more underrepresented racial/ethnic groups. Hispanic/Latino (Hispanic) persons were the largest group by population size (3.5 million persons) living in hotspot counties where a disproportionate number of cases among that group was identified, followed by black/African American (black) persons (2 million), American Indian/Alaska Native (AI/AN) persons (61,000), Asian persons (36,000), and Native Hawaiian/other Pacific Islander (NHPI) persons (31,000). Examining county-level data disaggregated by race/ethnicity can help identify health disparities in COVID-19 cases and inform strategies for preventing and slowing SARS-CoV-2 transmission. More complete race/ethnicity data are needed to fully inform public health decision-making. Addressing the pandemic's disproportionate incidence of COVID-19 in communities of color can reduce the community-wide impact of COVID-19 and improve health outcomes.
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Infecções por Coronavirus/etnologia , Etnicidade/estatística & dados numéricos , Disparidades nos Níveis de Saúde , Pneumonia Viral/etnologia , Grupos Raciais/estatística & dados numéricos , COVID-19 , Infecções por Coronavirus/epidemiologia , Humanos , Incidência , Pandemias , Pneumonia Viral/epidemiologia , Estados Unidos/epidemiologiaRESUMO
Zika virus (ZIKV) infection in pregnancy is associated with severe abnormalities of the brain and eye and other adverse outcomes. Zika en Embarazadas y Niños was a prospective cohort study conducted in multiple Colombian cities that enrolled pregnant women in their first trimester. Specimens collected from pregnant women (n = 1,519) during February 2017-September 2018 and their infants (n = 1,080) during June 2017-March 2019 were tested for prenatal ZIKV infection by nucleic acid amplification tests or IgM antibody testing. Zika virus infection in pregnancy was present in 3.2% of pregnant women (incidence rate [IR] per 1,000 person-months = 5.9, 95% CI: 4.3-7.8). Presumptive ZIKV infection was present in 0.8% of infants (IR = 1.6, 95% CI: 0.7-2.9). Five percent of infants with prenatal ZIKV exposure or infection presented with Zika-associated abnormalities; 4.7% were small for gestational age. Understanding the risk of ZIKV infection during pregnancy and associated adverse outcomes can help inform counseling efforts.
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PURPOSE OF REVIEW: In the past years, the importance of studying leptospirosis in a translational context has become more evident. This review addresses recent findings in the study of leptospirosis infection, focusing on those applicable to public health, or that will affect management and diagnosis of cases of leptospirosis. RECENT FINDINGS: We review here recent findings regarding translational aspects of leptospirosis research. Briefly, PCR or a combination of serology and PCR seem to have a higher sensitivity than the current gold standard (microagglutination test). More clinical trials are needed to determine the best treatment for mild and severe leptospirosis. Dendritic cells and γδ T cells seem to have an important role in the immune response to leptospirosis. Environmental assessment is emerging as a very useful tool. SUMMARY: In order to understand leptospirosis, multiple aspects need to be considered, including host, pathogen and environment. In this review, we will address newer diagnostics, current advances in immunology and treatment and the growing role of environmental assessment.
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Leptospirose/diagnóstico , Leptospirose/terapia , Pesquisa Translacional Biomédica , Animais , Humanos , Zoonoses/microbiologiaRESUMO
PURPOSE: Information on incentives for COVID-19 testing is needed to understand effective practices that encourage testing uptake. We describe characteristics of those who received an incentive after performing a rapid antigen test. DESIGN: Cross-sectional descriptive analysis of survey data. SETTING: During April 29-May 9, 2021, COVID-19 rapid antigen testing was offered in 2 Maryland cities. SAMPLE: Convenience sample of 553 adults (≥18 years) who tested and received an incentive; 93% consented to survey. MEASURES: Survey questions assessed reasons for testing, testing history, barriers, and demographics. ANALYSIS: Robust Poisson regressions were used to determine characteristic differences based on testing history and between participants who would re-test in the future without an incentive vs participants who would not. RESULTS: The most common reasons for testing were the desire to be tested (n = 280; 54%) and convenience of location (n = 146; 28%). Those motivated by an incentive to test (n = 110; 21%) were 5.83 times as likely to state they would not test again without an incentive, compared to those with other reasons for testing (95% CI: 2.67-12.72, P < .001). CRITICAL LIMITATIONS: No comparative study group. CONCLUSION: Results indicate internal motivation and convenience were prominent factors supporting testing uptake. Incentives may increase community testing participation, particularly among people who have never tested. Keywords COVID-19, pandemic, incentives, health behavior, community testing.
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COVID-19 , Motivação , Adulto , Humanos , Maryland , Teste para COVID-19 , Estudos Transversais , COVID-19/diagnósticoRESUMO
BACKGROUND: Sialic acids are negatively charged nine carbon backbone sugars expressed on mammalian cell surfaces. Sialic acids are part of a larger family of nonulosonic acid (NulO) molecules that includes pseudaminic and legionaminic acids. Microbial expression of sialic acids and other nonulosonic acids has been shown to contribute to host-microbe interactions in a variety of contexts, including participation in colonization, immune subversion, and behaviors such as biofilm formation, autoagglutination and motility. Previous research has suggested that some spirochetes may also express these molecules. RESULTS: Here we use a combination of molecular tools to investigate the presence of NulO biosynthetic gene clusters among clinical and saprophytic isolates of the genus Leptospira. Polymerase chain reaction and Southern blotting suggested that a variety of leptospires encoded NulO biosynthetic pathways. High performance liquid chromatography and mass spectrometry analyses provided biochemical evidence that di-N-acetylated NulO molecules are expressed at relatively high levels by L. interrogans serovar Lai strain 55601, and at lower levels by L. alexanderi serovar Manhao and L. fainei serovar Hurstbridge. Endogenous expression of N-acetylneuraminic acid (Neu5Ac, the most common sialic acid) was documented in L. interrogans serovar Copenhageni strain L1-130. Neu5Ac biosynthesis is also supported by a unique gene fusion event resulting in an enzyme with an N-terminal N-acetylneuraminic acid synthase domain and a C-terminal phosphatase domain. This gene fusion suggests that L. interrogans uses a Neu5Ac biosynthetic pathway more similar to animals than to other bacteria. Analysis of the composition and phylogeny of putative NulO biosynthetic gene clusters in L. interrogans serovar Lai and serovar Copenhageni revealed that both strains have complete biosynthetic pathways for legionamimic acid synthesis, a molecule with the same stereochemistry as sialic acid. Lectin-based affinity purification of NulO-modified molecules, followed by mass spectrometric identification suggests post-translational modification of surface lipoproteins, including Loa22. CONCLUSIONS: Leptospira species encode NulO biosynthetic pathways and synthesize multiple NulO molecules including sialic acid. Additional studies are needed to clarify the exact context and functional significance of NulO expression. These findings have implications for immune evasion during systemic leptospirosis.