Coxiella burnetii in humans and ticks in rural Senegal.
BACKGROUND
Q fever is a worldwide zoonotic disease caused by Coxiella burnetii. Epidemiologically, animals are considered reservoirs and humans incidental hosts.


RESULTS
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
Q fever should be considered a significant public health threat in Senegal. Humans, similar to other mammals, may continuously excrete C. burnetii.
Mediannikov
Oleg
O
URMITE, UMR IRD 198/CNRS 6236, Mediterranean University, Medical Faculty, Marseille, France.
Fenollar
Florence
F
Socolovschi
Cristina
C
Diatta
Georges
G
Bassene
Hubert
H
Molez
Jean-François
JF
Sokhna
Cheikh
C
Trape
Jean-François
JF
Raoult
Didier
D
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood*; D015373:Bacterial Typing Techniques; D002648:Child; D002675:Child, Preschool; D016000:Cluster Analysis; D016997:Coxiella burnetii / Q000145:classification* / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification*; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D005243:Feces / Q000382:microbiology; D005260:Female; D005838:Genotype; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D008895:Milk, Human / Q000382:microbiology; D016133:Polymerase Chain Reaction; D011778:Q Fever / Q000453:epidemiology* / Q000276:immunology / Q000382:microbiology; D012424:Rural Population; D012675:Senegal / Q000453:epidemiology; D017422:Sequence Analysis, DNA; D016036:Seroepidemiologic Studies; D013987:Ticks / Q000382:microbiology*; D055815:Young Adult
D000907:Antibodies, Bacterial; D004269:DNA, Bacterial
Eur J Epidemiol. 2003;18(3):263-6
12800953
Rocz Akad Med Bialymst. 1996;41(1):136-41
8673799
J Clin Microbiol. 1998 Jul;36(7):1823-34
9650920
Vet Microbiol. 1998 Nov;64(1):1-5
9874098
Dtsch Tierarztl Wochenschr. 2004 Oct;111(10):390-4
15568636
Infect Dis Clin North Am. 2008 Sep;22(3):505-14, ix
18755387
Emerg Infect Dis. 2005 Aug;11(8):1211-7
16102309
Public Health Rep (1896). 1947 Sep 26;62(39):1413-6
20344767
J Parasitol. 1948 Dec;34(6):457-64
18099928
Am J Trop Med Hyg. 1994 Aug;51(2):123-37
8074247
Lancet. 2006 Jul 1;368(9529):37-43
16815378
J Clin Microbiol. 1996 Mar;34(3):664-70
8904434
Indian J Med Res. 1981 Apr;73:510-2
7262921
Postgrad Med J. 2000 Feb;76(892):113-4
10644395
Clin Diagn Lab Immunol. 1994 Mar;1(2):189-96
7496944
Bull Soc Pathol Exot Filiales. 1970 Sep-Oct;63(5):530-4
4931489
QJM. 2005 Aug;98(8):615-7; author reply 617-20
16027172
Tropenmed Parasitol. 1975 Jun;26(2):219-31
1172309
Rev Infect Dis. 1983 Jul-Aug;5(4):790-800
6622891
BMC Microbiol. 2004 May 17;4:21
15147587
Zh Mikrobiol Epidemiol Immunobiol. 2005 Nov-Dec;(6):57-9
16438377
Z Tropenmed Parasitol. 1953 Jun;4(3):344-82
13103581
Clin Infect Dis. 1995 Nov;21(5):1126-33
8589132
Vopr Virusol. 1960 Sep-Oct;6:591-8
13719371
Trans R Soc Trop Med Hyg. 1991 May-Jun;85(3):397-8
1949146
Eur J Epidemiol. 1991 May;7(3):299-303
1884784
BMC Microbiol. 2007 Oct 18;7:91
17949485
Clin Infect Dis. 2009 Mar 1;48(5):558-9
19191639