Expanding molecular diagnostic coverage for tuberculosis by combining computer-aided chest radiography and sputum specimen pooling: a modeling study from four high-burden countries.

Background: In 2022, fewer than half of persons with tuberculosis (TB) had access to molecular diagnostic tests for TB due to their high costs. Studies have found that the use of artificial intelligence (AI) software for chest X-ray (CXR) interpretation and sputum specimen pooling can each reduce the cost of testing. We modeled the combination of both strategies to estimate potential savings in consumables that could be used to expand access to molecular diagnostics. Methods: We obtained Xpert testing and positivity data segmented into deciles by AI probability scores for TB from the community- and healthcare facility-based active case finding conducted in Bangladesh, Nigeria, Viet Nam, and Zambia. AI scores in the model were based on CAD4TB version 7 (Zambia) and qXR (all other countries). We modeled four ordinal screening and testing approaches involving AI-aided CXR interpretation to indicate individual and pooled testing. Setting a false negative rate of 5%, for each approach we calculated additional and cumulative savings over the baseline of universal Xpert testing, as well as the theoretical expansion in diagnostic coverage. Results: In each country, the optimal screening and testing approach was to use AI to rule out testing in deciles with low AI scores and to guide pooled vs individual testing in persons with moderate and high AI scores, respectively. This approach yielded cumulative savings in Xpert tests over baseline ranging from 50.8% in Zambia to 57.5% in Nigeria and 61.5% in Bangladesh and Viet Nam. Using these savings, diagnostic coverage theoretically could be expanded by 34% to 160% across the different approaches and countries. Conclusions: Using AI software data generated during CXR interpretation to inform a differentiated pooled testing strategy may optimize TB diagnostic test use, and could extend molecular tests to more people who need them. The optimal AI thresholds and pooled testing strategy varied across countries, which suggests that bespoke screening and testing approaches may be needed for differing populations and settings. Supplementary Information: The online version contains supplementary material available at 10.1186/s44263-024-00081-2.

Distinguishing Isomeric Cyclobutane Thymidine Dimers by Ion Mobility and Tandem Mass Spectrometry.

Irradiation of the major conformation of duplex DNA found in cells (B form) produces cyclobutane pyrimidine dimers (CPDs) from adjacent pyrimidines in a head-to-head orientation (syn) with the C5 substituents in a cis stereochemistry. These CPDs have crucial implications in skin cancer. Irradiation of G-quadruplexes and other non-B DNA conformations in vitro produces, however, CPDs between nonadjacent pyrimidines in nearby loops with syn and head-to-tail orientations (anti) with both cis and trans stereochemistry to yield a mixture of six possible isomers of the T=T dimer. This outcome is further complicated by formation of mixtures of nonadjacent CPDs of C=T, T=C, and C=C, and successful analysis depends on development of specific and sensitive methods. Toward meeting this need, we investigated whether ion mobility mass spectrometry (IMMS) and MS/MS can distinguish the cis,syn and trans,anti T=T CPDs. Ion mobility can afford baseline separation and give relative mobilities that are in accord with predicted cross sections. Complementing this ability to distinguish isomers is MS/MS collisional activation where fragmentation also distinguishes the two isomers and confirms conclusions drawn from ion mobility analysis. The observations offer early support that ion mobility and MS/MS can enable the distinction of DNA photoproduct isomers.

A novel subsurface slopes hazardous mapping with engineering geologic and geophysical characterizations.

Engineering geological characterizations, and geophysical mapping of subsurface structures to monitor some susceptible infrastructural facilities to hazardous slopes for effectiveness, safety to lives and properties, in addition to policy management for sustainable development. Novel integrated engineering geology, geoelectrical resistivity (ER), and borehole data analysis, to characterize subsurface for slope instability, determining critical zones prone to hazardous slopes in Peninsular Malaysian (PM), east coast areas was focused on. Engineering Laboratory soil investigations using disturbed and undisturbed samples collected to obtain firsthand information on the subsurface soils, and rocks physical properties, integrated with ER data to obtain subsurface geoelectric profiles. Regions delineated as loose and marked as water saturated residual soils prone to slopes corresponds to ER values < 100 Ω-m. ER values between 100 ≥ 500 Ω-m, were delineated as residual soils zones devoid of water contents. Subsurface geoelectric profiles related to hard materials were delineated as weathered and fractured bedrock zones corresponding to ER values between 500 ≥ 2000 Ω-m. Granitic bedrock units delineated as subsurface lithological zones with ER values > 4000 Ω-m. Slope Mass Ratings (SMR), was carried out to construct suitability, and slope assessment system (SAS) model ratings map for the four classes obtained.

Perceptions of TB-HIV comorbidity among the Nomads in Adamawa State, Nigeria.

The recalcitrance of Mycobacterium tuberculosis (MTB) to eradication was related to achieving a nonreplicating (dormant) state and the increasing global burden of HIV coinfection. Consequently, understanding the knowledge and perception of the population at risk of tuberculosis-HIV infection is essential to designing a strategy of intervention embraced by the target population. A cross-sectional study was conducted among Nomads in Adamawa State, Nigeria. A multistage sampling technique was employed to recruit consented participants. Self-administered questionnaires were used to gather the required information from 4 nomadic schoolteachers in each selected school. Data were entered into a Microsoft Excel sheet where trends and tables of collated data were developed. The findings show that only 13.5% of the participants expressed the correct perceptions of the complementary relationship between HIV and TB. More people in government employment (35%) understand the coexisting relationship of TB-HIV infections. At the same time, cattle herders and crop farmers who practice the prevalent occupation lack knowledge of TB-HIV relatedness. Across gender, only a proportion of males (14.8%) than females (10.5%) were more likely to show an understanding of the complementary association of HIV and TB, and this difference showed statistical significance (p = 0.0001). In conclusion, male gender, education at a degree or professional level, and employment with the government are factors associated with positive perceptions of TB/HIV relatedness. Thus, there is a need to intensify communication to educate Nomads on HIV and TB-related issues.

Safety of bubble nasal intermittent positive pressure ventilation (NIPPV) versus bubble nasal continuous positive airway pressure (NCPAP) in preterm infants with respiratory distress.

OBJECTIVE: Nasal Intermittent Positive Pressure Ventilation (NIPPV) is an effective therapy for infants in respiratory distress. We here report the safety of a novel, low-cost, non-electric bubble NIPPV device in comparison with bubble NCPAP. STUDY DESIGN: At Paramitha Children's Hospital (Hyderabad, India), preterm (n = 60) neonates with moderate respiratory distress were pragmatically allocated to bubble NCPAP (5-8 cm H2O) or bubble NIPPV (Phigh 8-12 cm H2O/Plow 5-8 cm H2O) based on staff and equipment availability. Primary outcomes to assess safety included clinically relevant pneumothorax, nasal septal necrosis, or abdominal distention. RESULTS: One patient in each arm developed minor nasal septal injury (grade 3 on NCPAP, grade 2 on NIPPV); no patients in either arm developed a clinically significant pneumothorax or abdominal distention. CONCLUSION: The similar rates of nasal septal injury, pneumothorax and abdominal distention suggest that bubble NIPPV has a similar safety profile as bubble NCPAP for preterm infants in respiratory distress.

Study of infection by Rickettsiae of the spotted fever group in humans and ticks in an urban park located in the City of Londrina, State of Paraná, Brazil / Estudo da infecção por Rickettsias do grupo da febre maculosa em humanos e carrapatos de um parque urbano na Cidade de Londrina, Estado do Paraná

INTRODUCTION: Spotted fevers are emerging zoonoses caused by Rickettsia species in the spotted fever group (SFG). Rickettsia rickettsii is the main etiologic agent of Brazilian spotted fever (BSF) and it is transmitted by Amblyomma spp. ticks. METHODS: The study aimed to investigate SFG rickettsiae in the Arthur Thomas Municipal Park in Londrina, PR, by collecting free-living ticks and ticks from capybaras and blood samples from personnel working in these areas. Samples from A. dubitatum and A. cajennense were submitted for PCR in pools to analyze the Rickettsia spp. gltA (citrate synthase gene). RESULTS: All the pools analyzed were negative. Human sera were tested by indirect immunofluorescence assay with R. rickettsii and R. parkeri as antigens. Among the 34 sera analyzed, seven (20.6 percent) were reactive for R. rickettsii: four of these had endpoint titers equal to 64, 2 titers were 128 and 1 titer was 256. None of the samples were reactive for R. parkeri. An epidemiological questionnaire was applied to the park staff, but no statistically significant associations were identified. CONCLUSIONS: The serological studies suggest the presence of Rickettsiae related to SFG that could be infecting the human population studied; however, analysis of the ticks collected was unable to determine which species may be involved in transmission to humans.

INTRODUÇÃO: A febre maculosa é uma zoonose emergente causada por espécies de Rickettsia do grupo febre maculosa (GFM). Rickettsia rickettsii é o principal agente etiológico da febre maculosa brasileira (FMB) e é transmitida por Amblyomma spp. MÉTODOS: Com o objetivo de obter informações sobre GFM Rickettsiae no Parque Municipal Arthur Thomas em Londrina, PR, carrapatos de vida livre e de capivaras foram coletados, assim como amostras de sangue das pessoas que trabalham no parque. A. dubitatum e A. cajennense foram submetidos à PCR em pools para analises de Rickettsia spp. gltA (citrate synthase gene). RESULTADOS: Todos os pools de carrapatos analizados foram negativos. Soros de humanos foram testados pela imunofluorescência indireta com antigenos de R. rickettsii e R. parkeri. Entre os 34 soros analisados, 7 (20,6 por cento) foram positivos para R. rickettsii. Destes, quatro apresentaram títulos iguais a 64, dois iguais a 128 e um, igual a 256, mas nenhum soro reagiu com R. parkeri. Não houve nenhuma associação, estatisticamente significante, entre as variáveis analisadas no questionário epidemiológico fornecido às pessoas que participaram da pesquisa. CONCLUSÕES: Os estudos sorológicos sugerem a presença de alguma Rickettsiae relacionada ao GFM que poderiam estar infectando a população humana estudada. Entretanto, as análises dos carrapatos foram inconclusivas para determinar qual espécie poderia estar envolvida na transmissão para os humanos.

Serosurvey of antibodies against spotted fever group Rickettsia spp. in horse farms in Northern Paraná, Brazil / Soroprevalência de anticorpos contra Rickettsia spp. do grupo febre maculosa em equinos de haras no Norte do Paraná, Brasil

Brazilian spotted fever (BSF) is an emerging disease most likely caused by Rickettsia rickettsii. The objective of the present study was to estimate the seroprevalence of BSF rickettsia infections in equines from six horse farms located in Londrina County, Paraná, Southern Brazil. Six owners of horse farms situated in Cambé, Santa Fé, Guaraci and Londrina municipalities participated in the study. All farms were located in areas where BSF has not been reported. A total of 273 horses were sampled and their sera were tested by indirect Immunofluorescence assay (IFA) using R. rickettsii and R. parkeri antigens. Titers equal to and greater than 64 were considered positive. Of 273 sera tested, 15 (5.5 percent) reacted to R. rickettsii and 5 (1.8 percent) to R. parkeri. Five out of the six farms studied revealed seropositive animals and seropositivity rate ranged from 0 to 13 percent. The titers ranged from 64 to 512, and four samples had a titer of 512. Nine animals reacted to R. rickettsii with titers four-fold higher than those for R. parkeri. These results suggest that horses in Northern Paraná may have been exposed to rickettsiae identical or closely related to R. rickettsii.

Febre Maculosa Brasileira (FMB) é uma doença emergente, sendo Rickettsia rickettsii o seu principal agente etiológico. O objetivo deste estudo foi determinar a soroprevalência de rickettsia do grupo da febre maculosa em equinos de seis haras localizados nos municípios de Cambé, Santa Fé, Guaraci e Londrina. As propriedades eram localizadas na região Norte do Paraná onde casos de FMB ainda não foram diagnosticados. Foram colhidas amostras de sangue de 273 equinos, e os soros foram testados pela RIFI, usando R. rickettsii e R. parkeri como antígenos, considerando-se como positivos títulos >64. Entre 273 soros, 15 (5,5 por cento) reagiram contra R. rickettsii e 5 (1,8 por cento) para R. parkeri. Cinco de seis haras estudados tinham animais reativos, e a taxa de sororreatividade variou de 0 a 13 por cento. Os títulos variaram de 64 para 512, e três amostras apresentaram título de 512. Nove animais reagiram para R. rickettsii com títulos quatro vezes maiores que para R. parkeri. Esses resultados sugerem que equinos no Norte do Estado do Paraná, Brasil, podem ter sido expostos a uma rickettsia idêntica ou muito próxima a R. rickettsii.