What type of study design best describes the collection of demographics and infection sources from patients with West Nile virus?

The study design that best describes the collection of demographics and infection sources from patients with West Nile virus is a case series. In a case series, researchers gather a detailed account of multiple patients who have a specific condition, in this case, West Nile virus infection. This type of study focuses on the clinical characteristics and outcomes of the patients, allowing researchers to explore demographic information and potential infection sources associated with the condition.

A case series typically does not involve a control group or the comparison of patients to those without the disease, which is more characteristic of case-control studies or cohort studies. Instead, it provides valuable descriptive data that can help in understanding the pattern and potentially the etiology of the disease, making it particularly useful for early observations in outbreaks or emerging infections.

Ultimately, the case series approach is valuable in generating hypotheses or guiding future research, especially when dealing with conditions that have not been widely studied.