Risk factors for intradomiciliary infestation by the Chagas disease vector Triatoma dimidiata in Jutiapa, Guatemala

Seventeen variables were evaluated as possible risk factors for the intradomiciliary infestation with Triatoma dimidiata in 644 houses in Jutiapa, Guatemala. During 2004 the houses were assessed for vector presence and evaluated for hygiene, cluttering, material comfort, construction conditions and number of inhabitants, among other factors. Chi-square analysis detected significant associations between vector presence and eight variables related to domestic sanitary and construction conditions. Log-linear models showed that regardless of the age of the house, the odds of vector presence were 4.3 and 10 times lower in houses with a good socioeconomic status compared with poor and very poor houses respectively. Log-linear models also pointed to a greater chance of vector presence when walls lacked plastering (3.85 times) or walls had low quality-incomplete plastering (4.56 times), compared with walls that were completely plastered. Control strategies against T. dimidiata should include the introduction of better-quality but inexpensive plastering formulations and better sanitation practices should also be promoted among the population. Such control strategies should not only reduce or eliminate infestation, but also prevent vector reinfestation

Collapsing Lesions and Focal Segmental Glomerulosclerosis in Pregnancy: A Report of 3 Cases

The relationship between focal segmental glomerulosclerosis (FSGS) and pregnancy is complex and not completely elucidated. Pregnancy in patients with FSGS poses a high risk for complications, possibly due to hemodynamic factors, imbalance between angiogenic and antiangiogenic factors, and hormonal conditioning. Although poor clinical outcomes associated with collapsing FSGS are common outside of pregnancy, the prognosis during pregnancy is not well documented. We report 3 patients who developed collapsing FSGS during pregnancy, 2 of whom had presumed underlying FSGS. Two patients underwent biopsy during pregnancy, and 1, during the puerperium. None of the 3 patients improved spontaneously after delivery, and 1 experienced a rapid deterioration in kidney function and proteinuria after delivery. Aggressive immunosuppressive therapy led to a full response in 1 case (without chronic lesions) and to partial responses in the remaining 2 cases. These cases suggest that collapsing lesions should be considered in patients with FSGS who develop a rapid increase in serum creatinine level or proteinuria during pregnancy and that these lesions may at least partially respond to treatment

Two Distinct Triatoma dimidiata (Latreille, 1811) Taxa Are Found in Sympatry in Guatemala and Mexico

Approximately 10 million people are infected with Trypanosoma cruzi, the causative agent of Chagas disease, which remains the most serious parasitic disease in the Americas. Most people are infected via triatomine vectors. Transmission has been largely halted in South America in areas with predominantly domestic vectors. However, one of the main Chagas vectors in Mesoamerica, Triatoma dimidiata, poses special challenges to control due to its diversity across its large geographic range (from Mexico into northern South America), and peridomestic and sylvatic populations that repopulate houses following pesticide treatment. Recent evidence suggests T. dimidiata may be a complex of species, perhaps including cryptic species; taxonomic ambiguity which confounds control. The nuclear sequence of the internal transcribed spacer 2 (ITS2) of the ribosomal DNA and the mitochondrial cytochrome b (mt cyt b) gene were used to analyze the taxonomy of T. dimidiata from southern Mexico throughout Central America. ITS2 sequence divides T. dimidiata into four taxa. The first three are found mostly localized to specific geographic regions with some overlap: (1) southern Mexico and Guatemala (Group 2); (2) Guatemala, Honduras, El Salvador, Nicaragua, and Costa Rica (Group 1A); (3) and Panama (Group 1B). We extend ITS2 Group 1A south into Costa Rica, Group 2 into southern Guatemala and show the first information on isolates in Belize, identifying Groups 2 and 3 in that country. The fourth group (Group 3), a potential cryptic species, is dispersed across parts of Mexico, Guatemala, and Belize. We show it exists in sympatry with other groups in Peten, Guatemala, and Yucatan, Mexico. Mitochondrial cyt b data supports this putative cryptic species in sympatry with others. However, unlike the clear distinction of the remaining groups by ITS2, the remaining groups are not separated by mt cyt b. This work contributes to an understanding of the taxonomy and population subdivision of T. dimidiata, essential for designing effective control strategies

SARS-CoV-2 Omicron is an immune escape variant with an altered cell entry pathway

Vaccines based on the spike protein of SARS-CoV-2 are a cornerstone of the public health response to COVID-19. The emergence of hypermutated, increasingly transmissible variants of concern (VOCs) threaten this strategy. Omicron (B.1.1.529), the fifth VOC to be described, harbours multiple amino acid mutations in spike, half of which lie within the receptor-binding domain. Here we demonstrate substantial evasion of neutralization by Omicron BA.1 and BA.2 variants in vitro using sera from individuals vaccinated with ChAdOx1, BNT162b2 and mRNA-1273. These data were mirrored by a substantial reduction in real-world vaccine effectiveness that was partially restored by booster vaccination. The Omicron variants BA.1 and BA.2 did not induce cell syncytia in vitro and favoured a TMPRSS2-independent endosomal entry pathway, these phenotypes mapping to distinct regions of the spike protein. Impaired cell fusion was determined by the receptor-binding domain, while endosomal entry mapped to the S2 domain. Such marked changes in antigenicity and replicative biology may underlie the rapid global spread and altered pathogenicity of the Omicron variant

Search for gravitational-lensing signatures in the full third observing run of the LIGO-Virgo network

Gravitational lensing by massive objects along the line of sight to the source causes distortions of gravitational wave-signals; such distortions may reveal information about fundamental physics, cosmology and astrophysics. In this work, we have extended the search for lensing signatures to all binary black hole events from the third observing run of the LIGO--Virgo network. We search for repeated signals from strong lensing by 1) performing targeted searches for subthreshold signals, 2) calculating the degree of overlap amongst the intrinsic parameters and sky location of pairs of signals, 3) comparing the similarities of the spectrograms amongst pairs of signals, and 4) performing dual-signal Bayesian analysis that takes into account selection effects and astrophysical knowledge. We also search for distortions to the gravitational waveform caused by 1) frequency-independent phase shifts in strongly lensed images, and 2) frequency-dependent modulation of the amplitude and phase due to point masses. None of these searches yields significant evidence for lensing. Finally, we use the non-detection of gravitational-wave lensing to constrain the lensing rate based on the latest merger-rate estimates and the fraction of dark matter composed of compact objects

An Unusual Cause of Acute Kidney Injury in Pregnancy: Beware of HELLP Look-Alikes

The differential diagnosis between new occurrence or revelation of chronic kidney diseases in pregnancy and hypertensive disorders of pregnancy is not easy, and the presence of a hypertensive disorder superimposed on a glomerular disease is even more challenging, as this case exemplifies. A 29-year-old woman was referred with HELLP (hemolysis, elevated liver enzymes, low platelets) syndrome at the end of her pregnancy. Immediately after cesarean delivery, she developed anuria, unexplained by blood loss or hypotension, and in the absence of known nephrotoxic drugs. While the laboratory features of HELLP rapidly resolved, AKI persisted, and the finding of high-level proteinuria was the hint leading to diagnosis of a glomerular disease (focal segmental glomerulosclerosis, FSGS), later proven by kidney biopsy. This case, reporting on the rare association between HELLP and FSGS, offers the opportunity to discuss the role of proteinuria, hypertension, and in the differential diagnosis of pregnancy-related acute kidney injury (pAKI)

An Unusual Cause of Acute Kidney Injury in Pregnancy: Beware of HELLP Look-Alikes

The differential diagnosis between new occurrence or revelation of chronic kidney diseases in pregnancy and hypertensive disorders of pregnancy is not easy, and the presence of a hypertensive disorder superimposed on a glomerular disease is even more challenging, as this case exemplifies. A 29-year-old woman was referred with HELLP (hemolysis, elevated liver enzymes, low platelets) syndrome at the end of her pregnancy. Immediately after cesarean delivery, she developed anuria, unexplained by blood loss or hypotension, and in the absence of known nephrotoxic drugs. While the laboratory features of HELLP rapidly resolved, AKI persisted, and the finding of high-level proteinuria was the hint leading to diagnosis of a glomerular disease (focal segmental glomerulosclerosis, FSGS), later proven by kidney biopsy. This case, reporting on the rare association between HELLP and FSGS, offers the opportunity to discuss the role of proteinuria, hypertension, and in the differential diagnosis of pregnancy-related acute kidney injury (pAKI)

Acute IgA-Dominant Glomerulonephritis Associated with Syphilis Infection in a Pregnant Teenager: A New Disease Association

Chronic kidney disease (CKD) is increasingly recognized as a risk factor in pregnancy; the differential diagnosis between CKD and preeclampsia (PE) may be of pivotal importance for pregnancy management and for early treatment of CKD. Acknowledging this connection may be useful also in a wider context, such as in the case reported in this paper, which for the first time describes an association between syphilis infection and IgA-dominant glomerulonephritis. A 16-year-old woman, referred to a general hospital due to a seizure, was found to be unknowingly pregnant. Based on hypertension and nephrotic proteinuria, she was initially diagnosed with PE. Immunological tests, as well as hepatitis and HIV tests showed negative results. However, secondary syphilis was diagnosed. In discordance with the PE diagnosis, urinalysis showed glomerular microhematuria with cellular casts. Proteinuria and hypertension did not remit after delivery, which was made via caesarean section, due to uncontrolled hypertension, at an estimated gestational age of 29 weeks. A male baby, weighing 1.1 kg (6.5 centile) was born. The baby was hospitalized in the neonatal intensive care unit, where he developed subependymal hemorrhage and thrombocytopenia, and neonatal syphilis was diagnosed. The mother underwent a kidney biopsy one week after delivery, leading to the diagnosis of IgA-dominant postinfectious glomerulonephritis. Mother and child were treated with support and antibiotic therapy, and were discharged in good clinical conditions four weeks later. Four months after delivery, the mother was normotensive without therapy, with normal kidney function and without hematuria or proteinuria. In conclusion, this case suggests that IgA-dominant postinfectious glomerulonephritis should be added to the spectrum of syphilis-associated glomerulonephritides, and underlines the need for a careful differential diagnosis with CKD in all cases of presumed PE. While diagnosis relies on kidney biopsy, urinary sediment, a simple and inexpensive test, can be the first step in distinguishing PE from other nephropathies

Demographic history and genetic structure in pre-Hispanic Central Mexico

International audienceAridoamerica and Mesoamerica are two distinct cultural areas in northern and central Mexico, respectively, that hosted numerous pre-Hispanic civilizations between 2500 BCE and 1521 CE. The division between these regions shifted southward because of severe droughts ~1100 years ago, which allegedly drove a population replacement in central Mexico by Aridoamerican peoples. In this study, we present shotgun genome-wide data from 12 individuals and 27 mitochondrial genomes from eight pre-Hispanic archaeological sites across Mexico, including two at the shifting border of Aridoamerica and Mesoamerica. We find population continuity that spans the climate change episode and a broad preservation of the genetic structure across present-day Mexico for the past 2300 years. Lastly, we identify a contribution to pre-Hispanic populations of northern and central Mexico from two ancient unsampled “ghost” populations