Chronic Kidney Disease in Agricultural Communities Numerous cases of chronic kidney disease of unknown cause have emerged among agricultural workers and other manual laborers in various regions of ...

https://www.nejm.org/doi/pdf/10.1056/NEJMra1813869

Chronic Kidney Disease of Unknown Cause in Agricultural Communities.

Recent studies have provided insights into innate and adaptive immune dynamics in coronavirus disease 2019 (COVID-19). However, the exact features of antibody responses that govern COVID-19 disease outcomes remain unclear. In this study, we analyzed humoral immune responses in 229 patients with asymptomatic, mild, moderate and severe COVID-19 over time to probe the nature of antibody responses in disease severity and mortality. We observed a correlation between anti-spike (S) immunoglobulin G (IgG) levels, length of hospitalization and clinical parameters associated with worse clinical progression. Although high anti-S IgG levels correlated with worse disease severity, such correlation was time dependent. Deceased patients did not have higher overall humoral response than discharged patients. However, they mounted a robust, yet delayed, response, measured by anti-S, anti-receptor-binding domain IgG and neutralizing antibody (NAb) levels compared to survivors. Delayed seroconversion kinetics correlated with impaired viral control in deceased patients. Finally, although sera from 85% of patients displayed some neutralization capacity during their disease course, NAb generation before 14 d of disease onset emerged as a key factor for recovery. These data indicate that COVID-19 mortality does not correlate with the cross-sectional antiviral antibody levels per se but, rather, with the delayed kinetics of NAb production.

/pdf/delayed-production-of-neutralizing-antibodies-correlates-r5x8mnjfwe.pdf

Delayed production of neutralizing antibodies correlates with fatal COVID-19.

Objective To assess whether exposure to high temperatures in pregnancy is associated with increased risk for preterm birth, low birth weight, and stillbirth. Design Systematic review and random effects meta-analysis. Data sources Medline and Web of Science searched up to September 2018, updated in August 2019. Eligibility criteria for selecting studies Clinical studies on associations between high environmental temperatures, and preterm birth, birth weight, and stillbirths. Results 14 880 records and 175 full text articles were screened. 70 studies were included, set in 27 countries, seven of which were countries with low or middle income. In 40 of 47 studies, preterm births were more common at higher than lower temperatures. Exposures were classified as heatwaves, 1°C increments, and temperature threshold cutoff points. In random effects meta-analysis, odds of a preterm birth rose 1.05-fold (95% confidence interval 1.03 to 1.07) per 1°C increase in temperature and 1.16-fold (1.10 to 1.23) during heatwaves. Higher temperature was associated with reduced birth weight in 18 of 28 studies, with considerable statistical heterogeneity. Eight studies on stillbirths all showed associations between temperature and stillbirth, with stillbirths increasing 1.05-fold (1.01 to 1.08) per 1°C rise in temperature. Associations between temperature and outcomes were largest among women in lower socioeconomic groups and at age extremes. The multiple temperature metrics and lag analyses limited comparison between studies and settings. Conclusions Although summary effect sizes are relatively small, heat exposures are common and the outcomes are important determinants of population health. Linkages between socioeconomic status and study outcomes suggest that risks might be largest in low and middle income countries. Temperature rises with global warming could have major implications for child health. Systematic review registration PROSPERO CRD 42019140136 and CRD 42018118113.

https://www.bmj.com/content/bmj/371/bmj.m3811.full.pdf

Associations between high temperatures in pregnancy and risk of preterm birth, low birth weight, and stillbirths: systematic review and meta-analysis.

This study examined the independent and combined importance of aerobic fitness and body fatness on physiological tolerance and exercise time during weight-bearing exercise while wearing a semipermeable protective ensemble. Twenty-four men and women were matched for aerobic fitness and body fatness in one of four groups (4 men and 2 women in each group). Aerobic fitness was expressed per kilogram of lean body mass (LBM) to eliminate the influence of body fatness on the expression of fitness. Subjects were defined as trained (T; regularly active with a peak aerobic power of 65 ml x kg LBM(-1) x min(-1)) or untrained (UT; sedentary with a peak aerobic power of 53 ml x kg LBM(-1) x min(-1)) with high (High; 20%) or low (Low; 11%) body fatness. Subjects exercised until exhaustion or until rectal temperature reached 39.5 degrees C or heart rate reached 95% of maximum. Exercise times were significantly greater in T(Low) (116 +/- 6.5 min) compared with their matched sedentary (UT(Low); 70 +/- 3.6 min) or fatness (T(High); 82 +/- 3.9 min) counterparts, indicating an advantage for both a high aerobic fitness and low body fatness. However, similar effects were not evident between T(High) and UT(High) (74 +/- 4.1 min) or between the UT groups (UT(Low) and UT(High)). The major advantage attributed to a higher aerobic fitness was the ability to tolerate a higher core temperature at exhaustion (the difference being as great as 0.9 degrees C), whereas both body fatness and rate of heat storage affected the exercise time as independent factors.

/pdf/influence-of-aerobic-fitness-and-body-fatness-on-tolerance-4yfgg44tal.pdf

Influence of aerobic fitness and body fatness on tolerance to uncompensable heat stress

/pdf/covid-19-is-a-systemic-vascular-hemopathy-insight-for-3tpozo38xs.pdf

COVID-19 is a systemic vascular hemopathy: insight for mechanistic and clinical aspects.

Objective:Recent findings suggest that laboring in hot occupational environments is related to kidney damage in agricultural workers. We examined hydration status and kidney function in 192 Florida agricultural workers.Methods:Blood and urine samples were collected over 555 workdays during the summe

Hydration Status, Kidney Function, and Kidney Injury in Florida Agricultural Workers.

Although agricultural workers have elevated risks of heat-related illnesses (HRI), pregnant farmworkers exposed to extreme heat face additional health risk, including poor pregnancy health and birth outcomes. Qualitative data from five focus groups with 35 female Hispanic and Haitian nursery and fernery workers provide details about the women's perceptions of HRI and pregnancy. Participants believe that heat exposure can adversely affect general, pregnancy, and fetal health, yet feel they lack control over workplace conditions and that they lack training about these specific risks. These data are being used to develop culturally appropriate educational materials emphasizing health promoting and protective behaviors during pregnancy.

/pdf/female-farmworkers-perceptions-of-heat-related-illness-and-3wzy5keau2.pdf

Female Farmworkers’ Perceptions of Heat-Related Illness and Pregnancy Health

Among patients with coronavirus disease (COVID-19), IgM levels increased early after symptom onset for those with mild and severe disease, but IgG levels increased early only in those with severe disease. A similar pattern was observed in a separate serosurveillance cohort. Mild COVID-19 should be investigated separately from severe COVID-19.

Antibody Profiles According to Mild or Severe SARS-CoV-2 Infection, Atlanta, Georgia, USA, 2020.

Purpose
To review factors that impact the effect of hot environments on the human body in order to develop a conceptual model of human biological response.

Methods
The organizing concept for the model development was the multilevel integration of three major factors, exposure to heat, sensitivity and adaptive capacity, and the heat stress response. Exposure of a vulnerable occupational group was used to illustrate the components of the model.

Findings
Components of this framework include the hazard (environmental heat stress), vulnerability factors (workplace exposure, sensitivity and adaptive capacity), and the heat stress response. The combination of the vulnerability factors of workplace exposure (work intensity, duration), sensitivity (age, gender, etc.), and adaptive capacity (hydration, clothing, work hygiene) mediate a worker's heat stress response to the hazard. A worker's heat stress response can be classified as progressing towards two outcomes: physiologic equilibrium or physiologic disequilibrium.

Conclusions
This framework provides a starting point for the design and development of studies of heat-related illness (HRI) in farmworker and other vulnerable populations exposed to rising global temperatures.

Clinical Relevance
Identification of vulnerability factors to HRI, informs research designs which will lead to the development of public health interventions.

/pdf/farmworker-vulnerability-to-heat-hazards-a-conceptual-2cy6c0e261.pdf

Farmworker Vulnerability to Heat Hazards: A Conceptual Framework.

Objective: The objective of this study was to determine the feasibility of field-based biomonitoring of heat-related illness (HRI) phenomena in Florida farmworkers. The authors determined feasibility through participant interviews regarding acceptability, data capture, recruitment and retention, and observed barriers and challenges to implementation. Methods: Study participants were employed in fernery operations in northeast Central Florida where ornamental ferns are grown and harvested in a seasonally high-heat environment. In this pilot, a total of 43 farmworkers participated during summers 2012 and 2013 and measurements included body core temperature, heart rate, energy expenditure, urine and blood osmolality, and self-reported HRI symptoms. Results: Data capture was approximately 90%. Participants reported that the study methods were nonobtrusive to their work, and that they were comfortable with study measures. Conclusions: These results open possibilities for characterizing HRI utilizing ph...

Valerie Mac

Papers

Hydration Status, Kidney Function, and Kidney Injury in Florida Agricultural Workers.

Female Farmworkers’ Perceptions of Heat-Related Illness and Pregnancy Health

Antibody Profiles According to Mild or Severe SARS-CoV-2 Infection, Atlanta, Georgia, USA, 2020.

Farmworker Vulnerability to Heat Hazards: A Conceptual Framework.

Heat Exposure in Central Florida Fernery Workers: Results of a Feasibility Study.