If patients with acute Q fever are re-examined for antibodies one year after their infection, 98% of the patients with chronic Q fever can be detected. In her PhD research Lieke Wielders, epidemiologist at RIVM and the Jeroen Bosch Ziekenhuis, argues in favour of such an additional check for Q fever patients.

Wielders believes that a once-only additional check one year after acute Q fever is sufficient to detect a chronic infection. A referral to the hospital and additional checks are required when antibodies are indicated to be elevated during the check one year after the acute infection. If a patient with acute Q fever is already known to have risk factors for a chronic infection (cardiac valve disease or a cardiovascular condition), several checks for antibodies need to take place in the first year.

Active call system for checks proves most effective

The actual manner of providing the check has a major effect on the number of acute Q fever patients checked within 15 months after the diagnosis. The research shows that more patients received a check (95%) with the laboratory that used an active call system compared to the laboratory that executed checks only upon application from a doctor (25%).

About the research

Wielders examined 1,289 acute Q fever patients for her PhD research, and a chronic Q fever infection was established among 58 patients. The infection became chronic within a year in 52 of these 58 patients (90%). The research provides clarity about when, how often and for how long acute Q fever patients require checking. Until today, there was no agreement on this in international literature.