Gert van der Hoek
In Memoriam - Editor, Senior Moderator
Interesting: humans as a possible reservoir of the CB (Q-fever) bacteria.
In the Netherlands Jan Richardus concluded more than 20 years ago:
a large part of the human population in the Netherlands is infected (with Q-fever,ed) (asymptomatic) in the first years of their live
Richardus did research on samples of breastmilk. He also found CB bacteria in human placenta's .
Summary by the author of his research (in Dutch):
http://www.rivm.nl/infectieziektenbulletin/bul91/q_koorts.html
Recently this study was published on research in Senegal, West Africa.
Coxiella burnetii in humans and ticks in rural Senegal.
some snips:
We investigated Q fever in rural Senegal.
Human samples (e.g., sera, saliva, breast milk, feces) were screened in the generally healthy population of two villages of the Sine-Saloum region.
Ticks were collected in four regions. Seroprevalence was studied by immunofluorescence, and all other samples were tested by two qPCR systems for detection of C. burnetii. Positive samples were genotyped (multispacer typing) by amplification and sequencing of three spacers. Strains were isolated by cell culture.
We found that the seroprevalence may be as high as 24.5% (59 of 238 studied) in Dielmo village. We identified spontaneous excretion of C. burnetii by humans through faeces and milk. Hard and soft ticks (8 species) were infected in 0-37.6%. We identified three genotypes of C. burnetii.
The previously identified genotype 6 was the most common in ticks in all studied regions and the only one found in human samples. Three strains of genotype 6 of C. burnetii were also recovered from soft tick Ornithodoros sonrai. Two other genotypes found in ticks, 35 and 36, were identified for the first time.
CONCLUSIONS/SIGNIFICANCE: Q fever should be considered a significant public health threat in Senegal. Humans, similar to other mammals, may continuously excrete C. burnetii.
Thus, we have found that in endemic areas, humans similar to other mammals may become chronic excretors of C. burnetii via feces and milk. Found rates of shedding are, however, not high and may not be compared with those identified in domestic animal.
The data presented from screening randomly collected samples show that serological and/or molecular evidence of contact/excretion of Q fever agents can be found quite often in a generally healthy rural population in Senegal.
In this work, we showed that in endemic region (with high seroprevalence in humans and high infection of ticks) humans may excrete the agent of Q fever even without evident clinical signs and during a long time. This gives us a possibility to speculate that humans, like other mammals, may be reservoirs of C. burnetii.
http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0000654
In the Netherlands Jan Richardus concluded more than 20 years ago:
a large part of the human population in the Netherlands is infected (with Q-fever,ed) (asymptomatic) in the first years of their live
Richardus did research on samples of breastmilk. He also found CB bacteria in human placenta's .
Summary by the author of his research (in Dutch):
http://www.rivm.nl/infectieziektenbulletin/bul91/q_koorts.html
Recently this study was published on research in Senegal, West Africa.
Coxiella burnetii in humans and ticks in rural Senegal.
some snips:
We investigated Q fever in rural Senegal.
Human samples (e.g., sera, saliva, breast milk, feces) were screened in the generally healthy population of two villages of the Sine-Saloum region.
Ticks were collected in four regions. Seroprevalence was studied by immunofluorescence, and all other samples were tested by two qPCR systems for detection of C. burnetii. Positive samples were genotyped (multispacer typing) by amplification and sequencing of three spacers. Strains were isolated by cell culture.
We found that the seroprevalence may be as high as 24.5% (59 of 238 studied) in Dielmo village. We identified spontaneous excretion of C. burnetii by humans through faeces and milk. Hard and soft ticks (8 species) were infected in 0-37.6%. We identified three genotypes of C. burnetii.
The previously identified genotype 6 was the most common in ticks in all studied regions and the only one found in human samples. Three strains of genotype 6 of C. burnetii were also recovered from soft tick Ornithodoros sonrai. Two other genotypes found in ticks, 35 and 36, were identified for the first time.
CONCLUSIONS/SIGNIFICANCE: Q fever should be considered a significant public health threat in Senegal. Humans, similar to other mammals, may continuously excrete C. burnetii.
Thus, we have found that in endemic areas, humans similar to other mammals may become chronic excretors of C. burnetii via feces and milk. Found rates of shedding are, however, not high and may not be compared with those identified in domestic animal.
The data presented from screening randomly collected samples show that serological and/or molecular evidence of contact/excretion of Q fever agents can be found quite often in a generally healthy rural population in Senegal.
In this work, we showed that in endemic region (with high seroprevalence in humans and high infection of ticks) humans may excrete the agent of Q fever even without evident clinical signs and during a long time. This gives us a possibility to speculate that humans, like other mammals, may be reservoirs of C. burnetii.
http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0000654