An article published this week stated that researchers have found a statistically significant correlation between enterovirus (Picornaviridae family) infection and Type 1 Diabetes Mellitus (T1DM). The study was a meta-analysis of 24 published articles and 2 abstracts from published articles about pre-diabetes autoimmunity or clinical diabetes. All studies used a case-control design.
The two associations found were associations between enterovirus infection and Diabetes-related autoimmunity (OR 3.7, [2.1-6.8]) and between enterovirus infection and clinical type 1 diabetes (OR 9.8, [5.5-17.4]
Of course, as with all correlational studies, there is need to be cautious when interpreting these findings and to remember that they are not causal. Because they do not demonstrate whether T1DM or enterovirus infection comes first, there is also no temporality implied. In addition, only 10 of the 24 studies used in the meta-analysis controlled for 3 or more known potentially confounding variables. Other environmental factors were not assessed, the articles were statistically very heterogeneous, and some of the laboratory techniques were questionable.
The study does, however, provide reason to perform larger studies that are prospective rather than retrospective to account for other potential cofounds, establish the missing temporality and to examine potential causal links. If these larger studies can find more causal links, the conclusions may help the development of new preventive and treatment techniques for T1DM, a disease that, according to the article, has been increasing in incidence by 3.9% a year.