Many sheep farm residents and veterinary students experienced a Q fever infection in the past, while only a few have had complaints of the acute illness. However, these people may still be at risk of a chronic infection. Although it is not known how high that risk is, I recommend to screen occupationally exposed people annually for a chronic infection when they have an additional risk factor. Risk factors for a chronic infection are having a cardiovascular disease or being immunocompromised. In this way, a chronic infection in occupationally exposed people can be detected in time.
Pregnant women who lived in an Q fever-affected area in 2008-2010, had not a higher risk for premature birth or perinatal mortality. However, there was a marginal higher risk for having a baby small for gestational age. Because of these results, it is not justified to screen all pregnant women and possibly treat them with antibiotics in an area with a Q fever outbreak.
Seven years after the large Dutch Q fever outbreak, still new chronic Q fever infections were diagnosed in patients with a heart valve defect. Also because of this reason, it is cost-effective to screen people with a risk factor once for chronic Q fever if they lived in Q fever affected areas.