Decrease in CD4 T-Cell Count and Risk of Severe Morbid Conditions in People With Human Immunodeficiency Virus Infection With Controlled Viral Load After Initiating Combination Antiretroviral Therapy Between 2006 and 2018.

BACKGROUND: A previous study showed an association between CD4 T-cell count decline in people with human immunodeficiency virus infection (PWH) with viral suppression and an increased risk of severe morbid conditions. We aimed to assess the risk of CD4 T-cell count decline (hereafter, CD4 decline), determine associated factors, and evaluate the association of this decline with the risk of severe morbid conditions (cardiovascular disease and cancer) or death. METHODS: From the Agence Nationale de Recherches sur le SIDA et les hépatites virales (ANRS) CO4 French Hospital Database on HIV cohort, we selected PWH >18 years old who had been followed up for ≥2 years after viral suppression following the initiation of combination antiretroviral therapy (cART) between 2006 and 2018. CD4 decline was defined as 2 consecutive relative differences ≥15%. Among participants with such decline, we modeled CD4, CD8, and total lymphocyte counts before and after CD4 decline, using spline regression. The remaining objectives were assessed using Poisson regression, with the association between CD4 decline and the risk of severe morbid conditions or death evaluated during or after 6 months of decline. RESULTS: Among 15 714 participants (75 417 person-years), 181 presented with CD4 decline (incidence rate, 2.4/1000 person-years (95% confidence interval, 2.1-2.8). CD8 and total lymphocyte counts also showed a similar decline. Older current age and lower viral load at treatment initiation were associated with the risk of CD4 decline. The risk of severe morbid conditions or death was 11-fold higher during the first 6 months for participants who presented with CD4 decline versus those who did not (incidence rate ratio, 10.8 [95% confidence interval, 5.1-22.8]), with no significant difference after 6 months. CONCLUSIONS: In PWH with viral suppression, CD4 decline was rare and related to global lymphopenia. It was associated with a higher risk of severe morbid conditions or death during the first 6 months.

Inferring long-distance connectivity shaped by air-mass movement for improved experimental design in aerobiology.

The collection and analysis of air samples for the study of microbial airborne communities or the detection of airborne pathogens is one of the few insights that we can grasp of a continuously moving flux of microorganisms from their sources to their sinks through the atmosphere. For large-scale studies, a comprehensive sampling of the atmosphere is beyond the scopes of any reasonable experimental setting, making the choice of the sampling locations and dates a key factor for the representativeness of the collected data. In this work we present a new method for revealing the main patterns of air-mass connectivity over a large geographical area using the formalism of spatio-temporal networks, that are particularly suitable for representing complex patterns of connection. We use the coastline of the Mediterranean basin as an example. We reveal a temporal pattern of connectivity over the study area with regions that act as strong sources or strong receptors according to the season of the year. The comparison of the two seasonal networks has also allowed us to propose a new methodology for comparing spatial weighted networks that is inspired from the small-world property of non-spatial networks.

Assessing the Aerial Interconnectivity of Distant Reservoirs of Sclerotinia sclerotiorum.

Many phytopathogenic fungi are disseminated as spores via the atmosphere from short to long distances. The distance of dissemination determines the extent to which plant diseases can spread and novel genotypes of pathogens can invade new territories. Predictive tools including models that forecast the arrival of spores in areas where susceptible crops are grown can help to more efficiently manage crop health. However, such models are difficult to establish for fungi with broad host ranges because sources of inoculum cannot be readily identified. Sclerotinia sclerotiorum, the pandemic agent of white mold disease, can attack >400 plant species including economically important crops. Monitoring airborne inoculum of S. sclerotiorum in several French cropping areas has shown that viable ascospores are present in the air almost all the time, even when no susceptible crops are nearby. This raises the hypothesis of a distant origin of airborne inoculum. The objective of the present study was to determine the interconnectivity of reservoirs of S. sclerotiorum from distant regions based on networks of air mass movement. Viable airborne inoculum of S. sclerotiorum was collected in four distinct regions of France and 498 strains were genotyped with 16 specific microsatellite markers and compared among the regions. Air mass movements were inferred using the HYSPLIT model and archived meteorological data from the global data assimilation system (GDAS). The results show that up to 700 km could separate collection sites that shared the same haplotypes. There was low or no genetic differentiation between strains collected from the four sites. The rate of aerial connectivity between two sites varied according to the direction considered. The results also show that the aerial connectivity between sites is a better indicator of the probability of the incoming component (PIC) of inoculum at a given site from another one than is geographic distance. We identified the links between specific sites in the trajectories of air masses and we quantified the frequencies at which the directional links occurred as a proof-of-concept for an operational method to assess the arrival of airborne inoculum in a given area from distant origins.