Gert van der Hoek
In Memoriam - Editor, Senior Moderator
EID Journal Home > Volume 17, Number 4–April 2011
Molecular Epidemiology of Coxiella burnetii from Ruminants in Q Fever Outbreak, the Netherlands
Hendrik I.J. Roest, and others
Abstract
Q fever is a zoonosis caused by the bacterium Coxiella burnetii. One of the largest reported outbreaks of Q fever in humans occurred in the Netherlands starting in 2007; epidemiologic investigations identified small ruminants as the source.
To determine the genetic background of C. burnetii in domestic ruminants responsible for the human Q fever outbreak, we genotyped 126 C. burnetii–positive samples from ruminants by using a 10-loci multilocus variable-number tandem-repeat analyses panel and compared them with internationally known genotypes.
One unique genotype predominated in dairy goat herds and 1 sheep herd in the human Q fever outbreak area in the south of the Netherlands. On the basis of 4 loci, this genotype is similar to a human genotype from the Netherlands. This finding strengthens the probability that this genotype of C. burnetii is responsible for the human Q fever epidemic in the Netherlands.
- snip -
The human Q fever outbreak in the Netherlands started in the southern part of the country and resulted in >3,500 human cases during 2007–2010.
Dairy goats and dairy sheep are considered to be the source of this outbreak, primarily on the basis of epidemiologic findings (10,17,20,21,25,26). In our study, samples were typed from farms suspected of being the source of the human Q fever outbreak.
Results show that 1 genotype of C. burnetii predominated in the dairy goats and sheep in the human Q fever outbreak area in the southern part of the Netherlands, and this genotype also was present in a human case-patient in the Netherlands.
This C. burnetii genotype is expected to have played a key role in the Q fever outbreak in small ruminants in the Netherlands and was also transmitted widely to humans, causing Q fever in the human population.
If this hypothesis holds true, C. burnetii with the same genotype as in dairy goats should be found in most samples from human Q fever patients. To this end, a study was performed to show the genetic background of human C. burnetii isolates in the Netherlands by using a concordant MLVA typing method (J.J.H.C. Tilburg et al., unpub. data).
Furthermore, the uniqueness of the predominant genotype of C. burnetii for the Netherlands can be part of the explanation why the magnitude of the Q fever outbreak in the Netherlands has never been seen elsewhere.
Full article
Comment: In the last quoted sentence the authors speculate the found genotype of CB bacteria in the Netherlands is more virulent than other genotypes, this could explain the magnitude of the outbreak. This is typical for Hendrik Jan Roest, he is fascinated with this idea, spreading it everywhere; so far no proof what so ever was found regarding virulence. The research is ongoing.
Molecular Epidemiology of Coxiella burnetii from Ruminants in Q Fever Outbreak, the Netherlands
Hendrik I.J. Roest, and others
Abstract
Q fever is a zoonosis caused by the bacterium Coxiella burnetii. One of the largest reported outbreaks of Q fever in humans occurred in the Netherlands starting in 2007; epidemiologic investigations identified small ruminants as the source.
To determine the genetic background of C. burnetii in domestic ruminants responsible for the human Q fever outbreak, we genotyped 126 C. burnetii–positive samples from ruminants by using a 10-loci multilocus variable-number tandem-repeat analyses panel and compared them with internationally known genotypes.
One unique genotype predominated in dairy goat herds and 1 sheep herd in the human Q fever outbreak area in the south of the Netherlands. On the basis of 4 loci, this genotype is similar to a human genotype from the Netherlands. This finding strengthens the probability that this genotype of C. burnetii is responsible for the human Q fever epidemic in the Netherlands.
- snip -
The human Q fever outbreak in the Netherlands started in the southern part of the country and resulted in >3,500 human cases during 2007–2010.
Dairy goats and dairy sheep are considered to be the source of this outbreak, primarily on the basis of epidemiologic findings (10,17,20,21,25,26). In our study, samples were typed from farms suspected of being the source of the human Q fever outbreak.
Results show that 1 genotype of C. burnetii predominated in the dairy goats and sheep in the human Q fever outbreak area in the southern part of the Netherlands, and this genotype also was present in a human case-patient in the Netherlands.
This C. burnetii genotype is expected to have played a key role in the Q fever outbreak in small ruminants in the Netherlands and was also transmitted widely to humans, causing Q fever in the human population.
If this hypothesis holds true, C. burnetii with the same genotype as in dairy goats should be found in most samples from human Q fever patients. To this end, a study was performed to show the genetic background of human C. burnetii isolates in the Netherlands by using a concordant MLVA typing method (J.J.H.C. Tilburg et al., unpub. data).
Furthermore, the uniqueness of the predominant genotype of C. burnetii for the Netherlands can be part of the explanation why the magnitude of the Q fever outbreak in the Netherlands has never been seen elsewhere.
Full article
Comment: In the last quoted sentence the authors speculate the found genotype of CB bacteria in the Netherlands is more virulent than other genotypes, this could explain the magnitude of the outbreak. This is typical for Hendrik Jan Roest, he is fascinated with this idea, spreading it everywhere; so far no proof what so ever was found regarding virulence. The research is ongoing.