Seasonality of blood neopterin levels in the Old Order Amish

Neopterin Levels in Bonobos Vary Seasonally and Reflect Symptomatic Respiratory Infections

As environmental changes exacerbate the threat coming from infectious diseases in wild mammal species, monitoring their health and gaining a better understanding of the immune functioning at the species level have become critically important. Neopterin is a biomarker of cell-mediated immune responses to intracellular infections. We investigated the variation of urinary neopterin (uNeo) levels of wild, habituated bonobos (Pan paniscus) in relation to individual and environmental factors. We used 309 urine samples collected between 2010 and 2018 at the LuiKotale field site, DRC. Based on current knowledge on zoo-housed conspecifics and closely related species, we predicted uNeo levels to increase (1) during infections, (2) with increasing age, (3) over the gestation period and in estrous females; and (4) to vary seasonally. Our results showed uNeo levels varied over a one-year period and increased in individuals showing respiratory symptoms. Contrary to chimpanzees, uNeo levels did not vary with age or female reproductive status, possibly due to our small sample size. Our study provides a baseline for a better understanding of bonobo's immunocompetence in the context of socio-ecological pressures and for monitoring the health of wild populations.

Seasonal affective disorder and seasonal changes in weight and sleep duration are inversely associated with plasma adiponectin levels

Overlapping pathways between mood and metabolic regulation have increasingly been reported. Although impaired regulation of adiponectin, a major metabolism-regulating hormone, has been implicated in major depressive disorder, its role in seasonal changes in mood and seasonal affective disorder-winter type (SAD), a disorder characterized by onset of mood impairment and metabolic dysregulation (e.g., carbohydrate craving and weight gain) in fall/winter and spontaneous alleviation in spring/summer, has not been previously studied. We studied a convenience sample of 636 Old Order Amish (mean (± SD), 53.6 (±14.8) years; 50.1% males), a population with self-imposed restriction on network electric light at home, and low prevalence of total SAD (t-SAD = syndromal + subsyndromal). We calculated the global seasonality score (GSS), estimated SAD and subsyndromal-SAD after obtaining Seasonal Pattern Assessment Questionnaires (SPAQs), and measured overnight fasting plasma adiponectin levels. We then tested associations between plasma adiponectin levels and GSS, t-SAD, winter-summer difference in self-reported sleep duration, and self-reported seasonal weight change, by using analysis of co-variance (ANCOVA) and linear regression analysis after adjusting for age, gender, and BMI. Participants with t-SAD (N = 14; 2.2%) had significantly lower plasma adiponectin levels (mean ± SEM, 8.76 ± 1.56 μg/mL) than those without t-SAD (mean ± SEM, 11.93 ± 0.22 μg/mL) (p = 0.035). In addition, there was significant negative association between adiponectin levels and winter-summer difference in self-reported sleep duration (p = 0.025) and between adiponectin levels and self-reported seasonal change in weight (p = 0.006). There was no significant association between GSS and adiponectin levels (p = 0.88). To our knowledge, this is the first study testing the association of SAD with adiponectin levels. Replication and extension of our findings longitudinally and, then, interventionally, may implicate low adiponectin as a novel target for therapeutic intervention in SAD.

No evidence for airborne transmission of Toxoplasma gondii in a very high prevalence area in Lancaster County

Background:

Toxoplasma gondii (T. gondii) has been associated with acute food-borne illness, chronic low-grade inflammation, neuropsychiatric conditions and reactivation of chronic latent infection in immunocompetent hosts. Primary infection with T. gondii in pregnant women can lead to congenital toxoplasmosis. In addition to well-known oral tissue-cyst or oocyst ingestion, we hypothesized that the very high prevalence of T. gondii in certain populations exposed to agricultural dust could be, in part, a consequence of airborne infection with oocysts.

Methods:

Wo collected environmental dust samples from an area with a reportedly high T. gondii seroprevalence in the Old Order Amish population, in Lancaster, Pennsylvania. Samples included: a) air filters from air-conditioning units; b) swabs of settled dust; and c) vacuum filters containing airborne field dust. Pools of the swabs and shredded sub-samples of the air filters were fed to pigs, with inoculation into mice of heart tissue from seroconverted pigs. We also investigated the presence of T. gondii DNA using PCR amplification.

Results:

Only one pig seroconverted. However, bioassay of pig heart tissue further inoculated into mice showed no evidence of T. gondii infection. Consistently, no evidence of T. gondii DNA was revealed in any sample.

Conclusions:

No evidence of airborne transmission was found in the environmental samples that were examined.