Genetically Modifying the Insect Gut Microbiota to Control Chagas Disease Vectors through Systemic RNAi

Technologies based on RNA interference may be used for insect control. Sustainable strategies are needed to control vectors of Chagas disease such as Rhodnius prolixus. The insect microbiota can be modified to deliver molecules to the gut. Here, Escherichia coli HT115(DE3) expressing dsRNA for the Rhodnius heme-binding protein (RHBP) and for catalase (CAT) were fed to nymphs and adult triatomine stages. RHBP is an egg protein and CAT is an antioxidant enzyme expressed in all tissues by all developmental stages. The RNA interference effect was systemic and temporal. Concentrations of E. coli HT115(DE3) above 3.35 × 107 CFU/mL produced a significant RHBP and CAT gene knockdown in nymphs and adults. RHBP expression in the fat body was reduced by 99% three days after feeding, returning to normal levels 10 days after feeding. CAT expression was reduced by 99% and 96% in the ovary and the posterior midgut, respectively, five days after ingestion. Mortality rates increased by 24-30% in first instars fed RHBP and CAT bacteria. Molting rates were reduced by 100% in first instars and 80% in third instars fed bacteria producing RHBP or CAT dsRNA. Oviposition was reduced by 43% (RHBP) and 84% (CAT). Embryogenesis was arrested in 16% (RHBP) and 20% (CAT) of laid eggs. Feeding females 105 CFU/mL of the natural symbiont, Rhodococcus rhodnii, transformed to express RHBP-specific hairpin RNA reduced RHBP expression by 89% and reduced oviposition. Modifying the insect microbiota to induce systemic RNAi in R. prolixus may result in a paratransgenic strategy for sustainable vector control

Use of a rapid test on umbilical cord blood to screen for Trypanosoma cruzi infection in pregnant women in Argentina, Bolivia, Honduras, and Mexico

Fil: Sosa-Estani, Sergio. ANLIS Dr.C.G.Malbrán. Centro Nacional de Diagnóstico e Investigación en Endemo-Epidemias; Argentina.Fil: Gamboa-León, Miriam Rubi. Universidad Autónoma de Yucatán. Laboratorio de Parasitología; México.Fil: Del Cid-Lemus, Jaime. Intibucá. Región Sanitaria No. 10; Honduras.Fil: Althabe, Fernando. Instituto de Efectividad Clínica y Sanitaria; Argentina.Fil: Alger, Jackeline. Instituto de Enfermedades Infecciosas y Parasitología Antonio Vidal; Honduras.Fil: Almendares, Olivia. Tulane University. School of Public Health and Tropical Medicine; Estados Unidos.Fil: Cafferata, María L. Hospital de Clínicas. Unidad de Investigación Clínica y Epidemiológica Montevideo; Uruguay.Fil: Chippaux, Jean-Philippe. L'Institut de recherche pour le développement (IRD); Bolivia.Fil: Dumonteil, Eric. Universidad Autónoma de Yucatán. Laboratorio de Parasitología; México.Fil: Gibbons, Luz. Instituto de Efectividad Clínica y Sanitaria; Argentina.Fil: Schneider, Dominique. L'Institut de recherche pour le développement (IRD); Bolivia.Fil: Belizán, José M. Instituto de Efectividad Clínica y Sanitaria; Argentina.Fil: Buekens, Pierre. Tulane University. School of Public Health and Tropical Medicine; Estados Unidos.Fil: Padilla-Raygoza, Nicolás. Universidad de Guanajuato; México.Fil: Perinatal Chagas Disease Working Group; Estados Unidos.We conducted a cross-sectional study of Chagas disease in five endemic areas in Argentina, Bolivia, Honduras, and México to estimate the prevalence of Trypanosoma cruzi–specific antibodies in pregnant women, and to assess the use of a rapid test (Chagas Stat-Pak) to screen for T. cruzi infection at the time of delivery. The prevalence of antibodies to T. cruzi measured by enzyme-linked immunosorbent assay (ELISA) in maternal blood was 5.5% (a range of 0.8–28.8% among the countries) in 2,495 women enrolled. Compared with ELISA in maternal blood samples, the Chagas Stat-Pak rapid test sensitivity and specificity in umbilical cord blood were 94.6% and 99.0%, respectively. These results show the ability for a rapid determination of the presence of T. cruzi–specific antibodies in umbilical cord blood as a pragmatic strategy to screen for infection in pregnant women

COVID-19 Deaths and Minority Health Social Vulnerability, in the U.S., January 1, 2020 through June 24, 2023

Background Health disparities, leading to worse health outcomes such as elevated COVID-19 mortality rates, are rooted in social and structural factors. These disparities notably impact individuals from lower socioeconomic backgrounds and more socially vulnerable areas. We analyzed the relationship between COVID-19 deaths and social vulnerability using the Minority Health Social Vulnerability Index (MHSVI). Methods COVID-19 death data in the U.S. was obtained from the Centers for Disease Control and Prevention (CDC) National Center for Health Statistics, where COVID-19 deaths were defned using the ICD-10 code U07.1. MHSVI composite scores were calculated for 3089 U.S. counties and categorized into social vulnerability quartiles, where values ranged from 0 (lowest vulnerability) to 1 (highest vulnerability). Negative binomial regression was employed to determine death rate ratios for each quartile within each theme. Finally, a multivariate negative binomial regression including all MHSVI sub-themes, excluding the overall index ranking, was used to assess the association between each theme and COVID-19 death rates independently. Results There were 1,134,272 COVID-19 deaths from January 1, 2020 through June 24, 2023. Adjusted rate ratios for COVID-19 deaths in the overall index ranking were 1.06 (95% CI 0.99-1.13), 1.14 (95% CI 1.06-1.22), and 1.41 (95% CI 1.31-1.52) for the second, third and fourth quartiles, respectively. Sub-themes of socioeconomic status (SES), household characteristics (HC), racial and ethnic minority status (REMS), housing type and transportation (HTT), and medical vulnerability (MV) revealed increasing death rates in higher vulnerability quartiles. The healthcare infrastructure and access (HIA) theme had decreasing death rate ratios of 0.74 (95% CI 0.71–0.78), 0.59 (95% CI 0.56–0.62), and 0.42 (95% CI 0.39–0.44) for the second, third, and fourth quartiles, respectively. Finally, the multivariate analysis showed that the HC, HTT, HIA, and MV themes were associated with COVID-19 deaths (P\u3c0.05). Conclusion Counties that were identifed as more socially vulnerable experienced higher death rates from COVID-19. These areas may need additional public health and social support during future pandemics

Deaths Associated with Pediatric Hepatitis of Unknown Etiology, United States, October 2021–June 2023

During October 2021–June 2023, a total of 392 cases of acute hepatitis of unknown etiology in children in the United States were reported to Centers for Disease Control and Prevention as part of national surveillance. We describe demographic and clinical characteristics, including potential involvement of adenovirus in development of acute hepatitis, of 8 fatally ill children who met reporting criteria. The children had diverse courses of illness. Two children were immunocompromised when initially brought for care. Four children tested positive for adenovirus in multiple specimen types, including 2 for whom typing was completed. One adenovirus-positive child had no known underlying conditions, supporting a potential relationship between adenovirus and acute hepatitis in previously healthy children. Our findings emphasize the importance of continued investigation to determine the mechanism of liver injury and appropriate treatment. Testing for adenovirus in similar cases could elucidate the role of the virus

School knowledge of infectious diseases in schools: conducting surveillance and on-demand, symptomatic respiratory viral testing in a large pre-kindergarten–12th grade school district

BackgroundLimited data about acute respiratory illness (ARI) and respiratory virus circulation are available in congregate community settings, specifically schools. To better characterize the epidemiology of ARI and respiratory viruses in schools, we developed School Knowledge of Infectious Diseases in Schools (School KIDS).MethodsSchool KIDS is a prospective, respiratory viral testing program in a large metropolitan school district (pre-kindergarten–12th grade) in Kansas City, Missouri. During the 2022–2023 school year, all students and staff were eligible to participate in surveillance respiratory viral testing at school by submitting observed self-administered nasal swabs monthly. Participants could also submit a nasal swab for on-demand symptomatic testing when experiencing ≥1 ARI symptom, including cough, fever, nasal congestion, runny nose, shortness of breath, sore throat, and/or wheezing. Swabs were tested in a research laboratory using multipathogen respiratory polymerase chain reaction assays. Participants were evaluated for ongoing viral shedding by collecting two weekly nasal swabs (i.e., convalescent), following initial on-demand symptomatic testing. Participants were asked to complete an electronic survey to capture the presence and type of ARI symptom(s) before the collection of respiratory swabs.ResultsFrom 31 October 2022 to 29 June 2023, School KIDS enrolled 978 participants, including 700 students, representing 3.4% of the district student population, and 278 staff members. Participants submitted a median of six surveillance, one symptomatic, and two convalescent specimens during the study period. A total of 6,315 respiratory specimens, including 4,700 surveillance, 721 on-demand symptomatic, and 894 convalescent specimens, were tested. Overall, a virus was detected in 1,168 (24.9%) surveillance and 363 (50.3%) symptomatic specimens. Of the 5,538 symptom surveys sent to participants before scheduled surveillance testing, 4,069 (73.5%) were completed; ARI symptoms were reported on 1,348 (33.1%) surveys.ConclusionRespiratory surveillance testing in schools is feasible and provides novel information about respiratory virus detections in students and staff attending school. Schools are an important community setting, and better knowledge of respiratory virus circulation in schools may be useful to identify respiratory virus transmission in the community and assess the impact of effective infection prevention measures

Reactive oxygen species and CAT specific activity in midguts of females fed with <i>E. coli</i> HT115(DE3) expressing CAT dsRNA.

<p>Females were fed blood alone, with <i>E. coli</i> HT115(DE3) expressing ANT dsRNA or CAT dsRNA, at 5.54 × 10⁷ CFU/mL blood. Midguts were dissected six days after feeding, incubated with dihydroethidium (DHE) and photographed under epifluorescence microscopy (Zeiss Observer.Z1 with Zeiss Axio Cam MrM using a filter set 10 (Exc 450–490 nm/ emission 515–565 nm)). Photographs show representative individuals from each group, inserts are differential interference contrast images. (B) Mean specific activity of CAT in insects fed <i>E. coli</i> HT115(DE3) expressing dsRNA CAT. Two biological replicates, n = 3 each. Error bars represent standard error of the mean. Asterisk indicates significant difference from control (<i>T</i>-test, <i>P</i>< 0.05).</p

Inhibition of molting and reduction in transcription levels of RHBP and CAT in third instar nymphs.

<p>Nymphs were fed blood with <i>E. coli</i> producing RHBP and CAT dsRNA. (A) Reduction of molting in third instar nymphs fed bacteria producing RHBP or CAT dsRNA as compared with nymphs fed blood without bacteria and with bacteria expressing ANT dsRNA (two biological replicates, n = 10 each). (B) Relative expression of RHBP in third instar nymphs fed bacteria producing RHBP dsRNA (two biological replicates, n = 3 each). (C) Relative expression of CAT in midguts of third instar nymphs fed with bacteria producing RHBP dsRNA (two biological replicates, n = 3 each). Asterisk indicates statistically different values compared with the control fed blood alone (<i>T</i>-test, <i>P</i>< 0.05).</p

Dose- and time-dependent effect of RHBP knockdown, and tissue-dependent effect of CAT knock-down, in adult females.

<p>Females were fed <i>E. coli</i> expressing dsRNA. RHBP (A) Expression of RHBP relative to actin on day five after feeding with different amounts of bacteria expressing RHBP dsRNA as compared to insects fed sterile blood: 2.24 × 10⁷ CFU/ml of blood (n = 6), 3.35 × 10⁷ CFU/ml of blood (n = 12) and 5.4 × 10⁷ CFU/ml of blood (n = 8). (B) Expression of RHBP in insects fed 5.4 × 10⁷ CFU/mL blood using bacteria expressing RHBP dsRNA, ANT dsRNA, and without dsRNA. Asterisk indicates statistically different values (<i>T</i>-test, <i>P</i>< 0.05) between experimental groups exposed to bacteria with RHBP dsRNA (n = 6), bacteria with ANT dsRNA (n = 8), bacteria without dsRNA (n = 6), as compared to groups fed blood alone (n = 6). (C) Time-dependent relative expression of RHBP in insects fed 5.4 × 10⁷ CFU bacteria/ml blood ten days after feeding. Asterisk indicates statistically different values (<i>T</i>-test, <i>P</i>< 0.05) between each group and the group fed sterile blood. CAT (D-G) Tissue-specific silencing in females fed with 5.4 × 10⁷ CFU/mL <i>E. coli</i> HT115(DE3) expressing dsRNA CAT or blood alone. (D) Anterior midgut, (E) posterior midgut, (F) fat body and (G) ovaries from each individual were processed to measure expression of CAT, relative to controls. Bars represent SEM, three biological replicates (n = 3 per replicate). In all, asterisk indicates statistically different values as compared to controls fed with blood alone (<i>T</i>-test, <i>P</i>< 0.05).</p

Impact of 13-Valent Pneumococcal Conjugate Vaccine on Invasive Pneumococcal Disease Among Adults With HIV—United States, 2008–2018

BackgroundPeople with HIV (PWH) are at increased risk for invasive pneumococcal disease (IPD). Thirteen-valent pneumococcal conjugate vaccine (PCV13) was recommended for use in US children in 2010 and for PWH aged 19 years or older in 2012. We evaluated the population-level impact of PCV13 on IPD among PWH and non-PWH aged 19 years or older.MethodsWe identified IPD cases from 2008 to 2018 through the Active Bacterial Core surveillance platform. We estimated IPD incidence using the National HIV Surveillance System and US Census Bureau data. We measured percent changes in IPD incidence from 2008 to 2009 to 2017-2018 by HIV status, age group, and vaccine serotype group, including serotypes in recently licensed 15-valent (PCV15) and 20-valent (PCV20) PCVs.ResultsIn 2008-2009 and 2017-2018, 8.4% (552/6548) and 8.0% (416/5169) of adult IPD cases were among PWH, respectively. Compared with non-PWH, a larger proportion of IPD cases among PWH were in adults aged 19-64 years (94.7%-97.4% vs. 56.0%-60.1%) and non-Hispanic Black people (62.5%-73.0% vs. 16.7%-19.2%). Overall and PCV13-type IPD incidence in PWH declined by 40.3% (95% confidence interval: -47.7 to -32.3) and 72.5% (95% confidence interval: -78.8 to -65.6), respectively. In 2017-2018, IPD incidence was 16.8 (overall) and 12.6 (PCV13 type) times higher in PWH compared with non-PWH; PCV13, PCV15/non-PCV13, and PCV20/non-PCV15 serotypes comprised 21.5%, 11.2%, and 16.5% of IPD in PWH, respectively.ConclusionsDespite reductions post-PCV13 introduction, IPD incidence among PWH remained substantially higher than among non-PWH. Higher-valent PCVs provide opportunities to reduce remaining IPD burden in PWH

Use of a rapid test on umbilical cord blood to screen for Trypanosoma cruzi infection in pregnant women in Argentina, Bolivia, Honduras, and Mexico

Fil: Sosa-Estani, Sergio. ANLIS Dr.C.G.Malbrán. Centro Nacional de Diagnóstico e Investigación en Endemo-Epidemias; Argentina.Fil: Gamboa-León, Miriam Rubi. Universidad Autónoma de Yucatán. Laboratorio de Parasitología; México.Fil: Del Cid-Lemus, Jaime. Intibucá. Región Sanitaria No. 10; Honduras.Fil: Althabe, Fernando. Instituto de Efectividad Clínica y Sanitaria; Argentina.Fil: Alger, Jackeline. Instituto de Enfermedades Infecciosas y Parasitología Antonio Vidal; Honduras.Fil: Almendares, Olivia. Tulane University. School of Public Health and Tropical Medicine; Estados Unidos.Fil: Cafferata, María L. Hospital de Clínicas. Unidad de Investigación Clínica y Epidemiológica Montevideo; Uruguay.Fil: Chippaux, Jean-Philippe. L'Institut de recherche pour le développement (IRD); Bolivia.Fil: Dumonteil, Eric. Universidad Autónoma de Yucatán. Laboratorio de Parasitología; México.Fil: Gibbons, Luz. Instituto de Efectividad Clínica y Sanitaria; Argentina.Fil: Schneider, Dominique. L'Institut de recherche pour le développement (IRD); Bolivia.Fil: Belizán, José M. Instituto de Efectividad Clínica y Sanitaria; Argentina.Fil: Buekens, Pierre. Tulane University. School of Public Health and Tropical Medicine; Estados Unidos.Fil: Padilla-Raygoza, Nicolás. Universidad de Guanajuato; México.Fil: Perinatal Chagas Disease Working Group; Estados Unidos.We conducted a cross-sectional study of Chagas disease in five endemic areas in Argentina, Bolivia, Honduras, and México to estimate the prevalence of Trypanosoma cruzi–specific antibodies in pregnant women, and to assess the use of a rapid test (Chagas Stat-Pak) to screen for T. cruzi infection at the time of delivery. The prevalence of antibodies to T. cruzi measured by enzyme-linked immunosorbent assay (ELISA) in maternal blood was 5.5% (a range of 0.8–28.8% among the countries) in 2,495 women enrolled. Compared with ELISA in maternal blood samples, the Chagas Stat-Pak rapid test sensitivity and specificity in umbilical cord blood were 94.6% and 99.0%, respectively. These results show the ability for a rapid determination of the presence of T. cruzi–specific antibodies in umbilical cord blood as a pragmatic strategy to screen for infection in pregnant women