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BACKGROUND: Systematic information on the association between community-level determinants and maternal health outcomes and disparities is needed. We aimed to investigate multi-dimensional place-based contributions to Black-White maternal health disparities in the United States. METHODS: We constructed the Maternal Vulnerability Index, a geospatial measure of vulnerability to poor maternal health. The index was linked to 13m live births and maternal deaths to mothers aged 10–44 for 2014–2018 in the United States. We quantified racial disparities in exposure to higher risk environments, and used logistic regression to estimate associations between race, vulnerability, and maternal death (n = 3633), low birthweight (n = 1.1m), and preterm birth (n = 1.3m). FINDINGS: Black mothers lived in disproportionately higher maternal vulnerability counties, when compared to White mothers (median of 55 vs 36/100 points). Giving birth in the highest-quartile MVI counties was associated with an increase in the odds of poor outcomes when compared to the lowest-quartile (aOR 1.43 [95% CI 1.20–1.71] for mortality, 1.39 [1.37–1.41] for low birthweight and 1.41 [1.39–1.43] for preterm birth, adjusted for age, educational attainment level and race/ethnicity). Racial disparities exist in low- and high-vulnerability counties: Black mothers in the least vulnerable counties remain at higher risk of maternal mortality, preterm birth, and low birthweight as White mothers in the most vulnerable. INTERPRETATION: Exposure to community maternal vulnerability is associated with increased odds of adverse outcomes, but the Black-White gap in outcomes remained under all vulnerability levels. Our findings suggest that locally-informed precision health interventions and further research into racism are needed to achieve maternal health equity. FUNDING: 10.13039/100000865Bill & Melinda Gates Foundation (grant number INV-024583).

Although community health workers (CHWs) are effective at mobilizing important health behaviors, there is limited evidence on how financial incentive systems can best be designed to drive their effectiveness. This study intends to bridge this evidence gap by analyzing the compensation model of India's accredited social health activist (ASHA) program and identifying areas of improvement in the system's design and implementation.We analyze the ASHA program in Uttar Pradesh, India. ASHAs receive compensation through a mix of program-linked, performance-based, and routine activity-based incentive structures. Using multiple data sources, including a novel linked household and ASHA survey, we estimate ASHA performance-linked incentive earnings under different scenarios of ASHA actions and household behaviors. Juxtaposing statistical projection models and actual government payments, we identified which incentives promised the highest payments, which were claimed or not, which could be claimed more by increasing ASHA actions, and which were paid despite not meeting payment criteria. We also report findings on ASHA awareness of and experiences with claiming incentives.We find crucial gaps and implementation challenges in the ASHA incentive structure. ASHAs could double their earnings by completing certain tasks within their control. ASHAs may also be paid for partial completion of activities, as incentives are paid in lump sums for a series of activities rather than for each activity. Family planning incentives have the largest gap between potential and actual earnings. Incentivizing ASHAs for achieving certain health outcomes is inefficient, as no clear linkage was found between the achievability of such health outcomes and the claim amounts.There are several opportunities for improving CHW compensation, from improving the incentive claims process to shifting focus to achievable outcomes. Optimizing incentive system designs can further enhance CHW effectiveness globally to affect key health behaviors.

While flagella-independent motility has long been described in representatives of the genus Acinetobacter, the mechanism of motility remains ambiguous. Acinetobacter baumannii, a nosocomial pathogen appearing increasingly multidrug-resistant, may profit from motility during infection or while persisting in the hospital environment. However, data on the frequency of motility skills among clinical A. baumannii isolates is scarce. We have screened a collection of 83 clinical A. baumannii isolates of different origin and found that, with the exception of one isolate, all were motile on wet surfaces albeit to varying degrees and exhibiting differing morphologies. Screening a collection of transposon mutants of strain ATCC 17978 for motility defects, we identified 2 akinetic mutants carrying transposon insertions in the dat and ddc gene, respectively. These neighbouring genes contribute to synthesis of 1,3-diaminopropane (DAP), a polyamine ubiquitously produced in Acinetobacter. Supplementing semi-solid media with DAP cured the motility defect of both mutants. HPLC analyses confirmed that DAP synthesis was abolished in ddc and dat mutants of different A. baumannii isolates and was re-established after genetic complementation. Both, the dat and ddc mutant of ATCC 17978 were attenuated in the Galleria mellonella caterpillar infection model. Taken together, surface-associated motility is a common trait of clinical A. baumannii isolates that requires DAP and may play a role in its virulence.

Human intestinal spirochetosis (HIS) is associated with overgrowth of the large intestine by spirochetes of the genus Brachyspira . The microbiological diagnosis of HIS is hampered by the fastidious nature and slow growth of Brachyspira spp. In clinical practice, HIS is diagnosed histopathologically, and a significant portion of cases may be missed. Fluorescence in situ hybridization (FISH) is a molecular method that allows the visualization and identification of single bacteria within tissue sections. In this study, we analyzed intestinal biopsy samples from five patients with possible HIS. All specimens yielded positive results by histopathological techniques. PCR amplification and sequencing of the 16S rRNA gene were performed. Sequences of two isolates clustered in the group of Brachyspira aalborgi , whereas in three cases, the sequences were highly similar to that of Brachyspira pilosicoli . Three phylotypes showed mismatches at distinct nucleotide positions with Brachyspira sp. sequences published previously. In addition, culture for Brachyspira was successful in three cases. On the basis of these data, we designed and evaluated a Brachyspira genus-specific 16S rRNA-directed FISH probe that detects all of the Brachyspira spp. published to date. FISH of biopsy samples resulted in strong, unequivocal signals of brush-like formations at the crypt surfaces. This technique allowed simultaneous visualization of single spirochetes and their identification as Brachyspira spp. In conclusion, FISH provides a fast and accurate technique for the visualization and identification of intestinal spirochetes in tissue sections. It therefore represents a valuable tool for routine diagnosis of HIS.

Unfed Ixodes ricinus nymphs were infected with eight different strains and clones of Borrelia afzelii and B. garinii by capillary feeding. Except one B. afzelii clone, all expressed OspC in culture. Tick midguts and salivary glands were investigated at different time intervals for the presence of borreliae and for OspA and OspC phenotypes by immunofluorescence with simultaneous staining of OspA and OspC with monoclonal antibodies. Both species were transmittable to I. ricinus . All OspC-expressing strains and clones were able to disseminate into the salivary glands. In contrast, the OspC-negative B. afzelii clone was not detectable in the salivary glands, an indication that OspC plays an important role in dissemination. OspA-positive borreliae prevailed in the midgut. OspC positives were more frequent in the salivary glands than in the midgut. Notably, simultaneously OspA- and OspC-negative borreliae were detected in both organs. Kinetics of dissemination varied with the strains. The OspC-positive B. afzelii clone and all B. garinii OspA type 4 strains were detectable in the salivary glands right after feeding, while one B. garinii OspA type 6 strain invaded the salivary glands with a delay of 24 h. These findings support the hypothesis that OspA is abundantly expressed in unfed ticks while upregulation of OspC is also a prerequisite for dissemination in the vector for the Eurasian species B. afzelii and B. garinii . However, we found strain-specific dynamics of Osp expression and strain-specific kinetics of systemic infection in the vector tick and it appears that additional factors are involved in the initiation and regulation of the dissemination process.

The risk of Borrelia burgdorferi sensu lato transmission from an infected vector tick to a host increases with increasing duration of tick feeding. In Ixodes ricinus nymphs, the main vector of B. burgdorferi s.l. in most parts of Europe, the transmission risk appears low to moderate within the first 24h of feeding but increases to >70% after only 36 h. In this study, the so-called scutal index, the ratio between tick abdominal length and scutum width, a very good measure of the level of tick engorgement, was investigated for its potential to assess the feeding duration of detached I. ricinus nymphs, thereby indicating the level of human infection risk with B. burgdorferi s.l. I. ricinus nymphs were allowed to feed in capsules on tick-naive Mongolian gerbils for 0, 12, 24, 36 h, or to repletion, in groups of up to 9 individuals. After tick removal, the scutal index of each tick (n=516) was determined using a stereomicroscope with an ocular micrometer. This was also possible, if the tick mouthparts were damaged. Although the scutal indices determined at 24 h versus 36 h post-attachment (a critical interval for B. burgdorferi transmission) differ significantly, there was some overlap between the two groups. However, by choosing a scutal index of 1.1 as a cut-off, it was possible to assign 93.2% of the ticks attached for 24h (n=310) to one group (low-risk group ticks) and 85.6% of those attached for 36 h (n=97) to the other (high-risk group ticks). This means that those people from whom I. ricinus nymphs with a scutal index >1.1 detached have a distinctly elevated risk of Borrelia infection and therefore more likely require medical attention.

The objective of this study was to visualize borreliae directly in whole-body sections of Ixodes ricinus by fluorescence in situ hybridization (FISH). Borrelia afzelii mono-infected or Borrelia burgdorferi sensu stricto (ss)/B. afzelii double-infected nymphs were fixed, embedded in cold polymerizing resin and sectioned. The same sample processing was applied to skin biopsies taken from a Mongolian gerbil after an infectious tick-bite. FISH was carried out using 16S-rRNA-directed, fluorescence-labelled oligonucleotide probes specific for the genus Borrelia and specific within the group of Lyme borreliosis-associated genospecies B. afzelii, B. burgdorferi ss, Borrelia garinii and Borrelia valaisiana. Sensitivity and specificity of the newly designed probes were evaluated using PCR, dot-blot hybridizations and FISH. Despite significant autofluorescence of certain tick tissues (which allowed good histological orientation within the sections), borreliae showing the typical spirochaetal morphotype were clearly visible in five out of six putatively infected ticks. These findings were confirmed by electron microscopy of ticks from the same infected batch as used for FISH. Attempts to produce ticks infected by two different Borrelia genospecies were not successful. FISH on whole-body sections of resin-embedded ticks offers the possibility of visualizing and identifying borreliae within tick tissues. This technique has great potential for the investigation of the transmission of bacteria or other micro-organisms by arthropod vectors. Furthermore, clear visualization of single spirochaetes distributed along subcutaneous fat cell membranes in gerbil skin biopsies suggests that FISH might also be suitable for the detection of borreliae in clinical tissue specimens.