Mesoamerican nephropathy (MeN), an epidemic of unexplained kidney disease in Central America, affects mostly young, healthy individuals. Its etiology is a mystery that requires urgent investigation. Largely described as a chronic kidney disease (CKD), no acute clinical scenario has been characterized. An understanding of the early disease process could elucidate an etiology and guide treatment and prevention efforts. We sought to document the earliest clinical signs in patients with suspected MeN in a high-risk population in Nicaragua. Physicians at a local hospital identified suspect cases and documented clinical/laboratory data, demographics, and medical histories. Over a 1-year period, physicians identified 255 mostly young (median 29 years), male (89.5%) patients with elevated creatinine or reduced creatinine clearance. Mean serum creatinine (2.0 ± 0.6 mg/dL) revealed a 2-fold increase from baseline, and half had stage 2 or 3 acute kidney injury. Leukocyturia (98.4%), leukocytosis (81.4%), and neutrophilia (86.2%) predominated. Nausea (59.4%), back pain (57.9%), fever (54.6%), vomiting (50.4%), headache (47.3%), and muscle weakness (45.0%) were common. A typical case of acute MeN presented with elevated (or increased ≥ 0.3 mg/dL or ≥ 1.5-fold from baseline) creatinine, no hypertension or diabetes, leukocyturia, and at least two of fever, nausea or vomiting, back pain, muscle weakness, headache, or leukocytosis and/or neutrophilia. Rapid progression (median 90 days) to CKD was recorded in 8.5% of patients. This evidence can serve as the basis of a sensitive and urgently needed case definition for disease surveillance of early-stage, acute MeN.

Heat stress is associated with numerous health effects that potentially harm workers, especially in a warming world. This investigation occurred in a setting where laborers are confronted with occupational heat stress from physically demanding work in high environmental temperatures. Collaboration with a major Nicaraguan sugarcane producer offered the opportunity to study interventions to prevent occupational heat-stress-related kidney disease. Two aims for this study of a rest-shade-water intervention program were: (1) describe the evolving intervention, summarize findings that motivated proposed improvements, assess impact of those improvements, and identify challenges to successful implementation and (2) extract primary lessons learned about intervention research that have both general relevance to investigations of work-related disease prevention and specific relevance to this setting. The learning curve for the various stakeholders as well as the barriers to success demonstrate that effectiveness of an intervention cannot be adequately assessed without considerations of implementation. Designing, effectively implementing, and assessing both health impacts and implementation quality is a resource-intensive endeavor requiring a transdisciplinary approach. Both general and specific lessons learned are presented for decisions on study design and study elements, implementation assessment, and management engagement in understanding how productivity and health can be successfully balanced and for building effective communication between investigators and all levels of management.