In keeping with recent recommendations, at minimum, adding sapovirus to routine diagnostics of infections that occur in any setting and by any mode of transmission will establish etiologies of some norovirus-negative outbreaks and help define the disease impact and clinical characteristics of sapovirus infections (9, 10, 13 ).
An animal model that replicates the established etiology or mechanism underlying a disease is commonly described as having etiologic validity [ 4, 5].
A small number of cases can be treated on a rational basis because of an established etiology.
Although previous respiratory disease was registered days before this condition, establishing etiology is quite a challenge, viruses being incriminated.
16S rDNA PCR was found to be a useful tool in establishing etiology in cases of infections caused by rare pathogens.
However, many cases of fetal ductal constriction, as well as of persistent neonatal pulmonary artery hypertension, remain without an established etiology, being referred as "idiopathic".
There was a trend for patients with Mycoplasma pneumonia receiving more often antimicrobial agents covering atypical bacteria than those with another bacterial or without established etiology.
Sepsis-associated AKI was the most common established etiology (n = 15), followed by pre-renal AKI (n = 8), and ischemic acute tubular necrosis (n = 5).
However, many cases of fetal ductal constriction, as well as of persistent neonatal pulmonary artery hypertension, remain without an established etiology, being referred as "idiopathic" (Shima et al., 2011).
The objective of this study was to elucidate the role of E. coli, Enterococcus spp., C. perfringens and C. difficile in neonatal porcine diarrhea with no previously established etiology.
