Whilst there is no certainty that an increase/decrease in clinical variables such as respiratory rate, WCC, CRP and serum albumin are alone due to CDI, as these patients are usually older, and have multiple co-morbidities, it is generally seen that these markers have usually returned to baseline levels before a later rise which occurs around the time of C. difficile diagnosis, which could be up to 1–2 weeks after cessation of antibiotic treatment for a previous condition. This evidence concerns the gene CRP and clostridium difficile infection.