Q-Kids

Q fever is a zoonosis caused by Coxiella burnetii. Most cases of Q fever are
reported in adults.1 While seroprevalence data in children are limited, they
nevertheless show that children and adolescents are frequently exposed to
Coxiella burnetii. Yet, little is known about the disease, its course and
associated risk factors in this group. Whereas existing literature suggests
that Q fever illness in children runs a milder course than in adults, it is
likely that the morbidity related to Q fever in children is underestimated as
many infections are overlooked or misdiagnosed. While children and teenagers
younger than 18 years represent about 17% of the population in South Limburg,
less than 10% of all individuals tested for Q fever in the year following the
veterinary outbreak were from that age category. Further research is necessary
to assess whether this discrepancy was caused by differences in exposure, in
immunological response to infection and/or in clinical presentation leading to
underdiagnosis due to milder or less specific signs and symptoms in younger
patients. Only 14% of all younger patients tested had IgM-antibodies to
Coxiella, whereas in adults 26% had evidence of acute or recent infection,
suggesting that clinical presentation in children may be an even less reliable
predictor of infection and disease than in adults. Missed diagnosis or
misdiagnosis in children and adolescents, as in adults, may lead to wrong,
delayed, or foregone treatment, with possible serious implications such as
late-onset chronic Q fever. While acute infection may affect normal development
and school performance in schoolchildren, e.g., through absenteeism or symptoms
related to a post-Q-fever fatigue syndrome similar to that in adults, this
relationship has never been studied before. Sequelae following acute Q fever
infection may be even more severe in children and adolescents with serious
learning difficulties, who may run additional behavioral risks of contracting
the infection, and whose ability to communicate subjective symptoms of disease
may be compromised by their disability, hampering adequate diagnosis and
treatment.

To estimate the risk of Q fever infection in children and adolescents in
various exposure groups, estimate the true regional incidence of Q fever
infections in children and adolescents, identify associated risk factors, and
assess the impact of Q fever infection on children*s and adolescents* health
and school performance status

Two retrospective cohort studies

Parents/guardian(s) of participating children and adolescents will be asked to
complete a questionnaire; participating children and adolescents will be asked
to have a small blood sample taken by finger-prick during a single dedicated
session at school. The researchers may collect data on health and performance
status of participating children and adolescents from various sources,
including the school, general practitioners and the youth health department of
the Public Health Service South Limburg; participants or parents/guardian/(s)
may refuse collection of these data by ticking the appropriate opting-out box
on the consent form. Estimated time required to complete the questionnaire is
approximately 15 minutes. Drawing blood by finger-prick is a proven method
which is minimally invasive and generally well-accepted by children. It carries
no risks to participants* health. Incidental confirmed positive results may
lead to some degree of psychological distress in the child and/or
parents/guardian(s), which, however, may be outweighed by potential benefits
(i.e., knowledge about Q-fever status and - in the unlikely event of acute or
ongoing Q fever infection - appropriate treatment of the child in question by
their GP, or referral to specialist care). Much attention will be given to
optimal patient information. Little is known about the incidence, risk factors
and potential sequelae of Q fever in children. Most cases of Q fever are
reported in adults. While seroprevalence data in children are limited, they
nevertheless show that children are frequently exposed to Coxiella burnetii.1
One of the reasons for this seeming contradiction is the marked difference in Q
fever*s clinical manifestation between children and adults. Generally speaking,
a milder course of disease and less specific symptoms seem to set children
apart from adults with regard to Q fever. In fact, Q fever in children an
adults may be considered two different disease entities, with important
discrepancies in epidemiology, clinical manifestation, and sequelae, even
though the pathophysiological basis for this phenomenon is open to discussion.
This means that conclusions drawn from studies in the general population where
the bulk of participants so far have been adults cannot simply be generalized
to children, as is the case with other subgroups where group-related studies
are already underway (e.g., Q fever in pregnant women). In other words,
important questions regarding Q fever in children and adolescents cannot be
answered from the available body of evidence which is hugely based on adult
data. The condition may be grossly underdiagnosed in children, in spite of
potentially subtle yet significant effects (such as decline in general health
and/or school performance), and children and adolescents at present may
inadequately benefit from new insights into the pathophysiology, diagnosis,
treatment and prognosis of Q fever. For these reasons, we strongly feel that Q
fever studies tailored to the particular subgroup of children and adolescents
are not only necessary but also long overdue.