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Q fever in France
Zbl. Bakt. Hyg. A 267, 26-29 (1987)
Q Fever in France E. A. ED LINGER Institut Pasteur, National Center of Reference for Rickettsioses, Unite de Diagnostic Virologique et Rickettsiales, Paris, France
With 1 Figure
Abstract In France Q fever is a notifiable disease, but information could only be obtained from fragmental inquiries. Routine serologic examination of 75 901 sera during the years 1982-85 showed 430 Q fever positive sera (mean rate 0.57%). Our laboratory could confirm 135 cases of clinical Q fever. In the region of Dijon, 4.4% of the country population was seropositive, but among breeders 25% were positive. 36 persons (8%) among 245 employees of the departmental veterinary services were seropositive, some with very high titers, but without obvious clinical symptoms. It seems that infection by Coxiella burnetiiis still largely underestimated.
In France Q fever is a notifiable disease but the scarce informations gathered have no practical consequences. The reports are supposed to be established weekly, but clinicians omit to do so. Thus I can only present some fragmental results of inquiries to assess the frequency of Q fever in France. The reports of the laboratories contain only serologic results but no information on clinical data. Furthermore, the serologic technique still mostly used is the complement fixation test with all its drawbacks. In Table 1 the serologic results from 30 laboratories - mostly from northern France - are presented. No clinical data were available. It may be presumed that the blood samples were taken from patients with acute respiratory diseases (3). The mean rate of Table 1. Serologic results from 30 laboratories (Data from the Influenza Reference Center, Institut Pasteur, Paris) Year
Sera examined
Seropositives
1982 1983 1984 1985
14557 18404 19830 23110
65 90 137 138
Total
75901
430 (0.57%)
(0.45%) (0.49%) (0.69%) (0.60%)
Q Fever in France
27
positive reactions was 0.57%. Thus one might suppose that either clinical indication for specific Q fever serology was not given orland the test procedure was not sensitive enough. The serologic results on 2614 serum samples obtained by the National Reference Center for Rickettsioses are presented in Table 2. The mean rate of seropositives (titers > 1:20) by the indirect fluorescence antibody test (IFAT) which is the routine test in our laboratory (2), was 23.4%. The reason for the high rate of positives may be prior selection of the sera according to clinical and epidemiologic informations. Table 2. Serodiagnosis of Q fever in the National Reference Center for Rickettsioses Year
Sera examined
Positives
1982 1983 1984 1985
588 385 590 1051
24 37 149 402
Total
2614
612 (23.4%)
Among them clinically confirmed Q fever cases
(4.0%) (9.6%) (25.0%) (38.0%)
9 13 30 81
(37.5%) (35.0%) (20.0%) (20.0%)
133 (21.7%)
Acute Q fever could be confirmed for one fifth (21.7%) of the 612 seropositives. Confirmation was based on increasing antibody titers in paired sera or on two high titers (> 1:1280), but always together with consistent clinical data. From an epidemiologic point of view, the relative frequency of reported contacts with goats and sheep has to be mentioned. An outbreak of Q fever in a family has been puzzling: a French officer returned from French Guyana with his wife and two children to his parents in Normandy. Some days after his arrival, he became ill, was hospitalized, and Q fever was diagnosed. His wife became ill with Q fever one month later which was regarded as probably too late for infection in Guyana. The patient's father and his sister living in France got also Q fever. The mother experienced no illness and did not develop specific antibodies. The two children got seropositive but not sick. We assumed that C. burnetii was present in the dust of the luggage arriving from Guyana; however, it was the mother who cleaned the clothes of the arrived family, and she remained uninfected. Here human to human transmission cannot be excluded. Other information about Q fever in France may be derived from seroepidemic surveys of exposed populations. Such a study was made in 1980 in the Departement Cote d'Or (Dijon) (1). Results of this investigation are presented in Table 3. In a Table 3. Seroepidemiologic survey in the Departement Cote d'Or (Dijon) Group
Sera
Indirect Fluorescence Antibody Test (IFAT)
% positive
I
966
43
4,4
II
86
22
25.0
Group I = country people selected at random Group II = animal breeders
28
E.A.Edlinger
randomly selected country population (62% men and 38% women) 4.4% were seropositive, but among 86 animal breeders 22 (26%) were positive. In France all persons of the departmental veterinary services must be screened every year for Q fever infection by law. The Health Service of the Agricultural Social Security advised that the sera should be sent to the reference center. Yet only 13 of 89 rural departments sent the sera of their employees. These departments - except one (Vosges) - were in the western part of France, mostly in the northwest (see Fig. 1). Livestock in these regions consists mainly of bovines; there are only few sheep and rarely goats. Results are presented in Table 4. Eighty-nine persons (36%) were seropositive, among them 36 (15%) with a titer> 1:160. The follow-up study showed 15 persons with rising titers, and 4 with descending titers. Five persons had high titers. One man working in a slaughterhouse for 43 years had a titer of 1:5120 in 1983, but thorough clinical examination proved that he had been in perfect health; in 1986 his titer was 1:320. The second titer of 1:5120 is that of a woman, 25 years old; she was working for one year in the autopsy room of a veterinary laboratory, was seropositive in 1985 and got pregnant in 1986; she has been in perfect health so far. No case of clinically overt Q fever was reported.
Fig.1. Departements participating in serologic surveys. 17 Eure
18 Eure et Loire
19 Finistere Sud
Maine et Loire 53 Mayenne 56 Morbihan Garonne 86 Vienne 88 Vosges
37 Indrc et Loire
72 Sarthe
41 Loir et Cher
79 Deux-Sevres
49
82 Tarn et
Q Fever in France
29
Table 4. Survey of the Departmental Veterinary Services 1982-1985 Indirect Fluorescence Antibody Test (IFAT) Persons examined
negative
positive
< 1:80
> 1:160
245
156
89 (36%)
53 (21.6%)
36 (15%)
Follow-up, variation of titer and high titers Follow-up
Titer variations
Persons examined
1 year
2 years
3 years
4 years
< 1/160 ~ 1/160 High titers 4x 4x ;:: 1/640
245
129
62
26
28
15
4
5"
* One serum: 1:640; two sera: 1:1280; two sera: 1:5120
These rather scarce medical informations about Q fever in France regrettably cannot be supplemented with data from veterinary investigations since the rather small investigations performed applied questionable techniques and were intended to explain abortions and stillbirths among cattle. Anyhow, it seems that infection by C. burnetii in man occurs frequently in France and is largely underestimated. Acknowledgements. Prof. Claude Hannoun, Influenza Reference Center, Institut Pasteur, Paris, kindly supplied the data of 30 laboratories.
References 1. Chavanet, P., A. Pechinot, C. Nussbaum, and A. Portier: Enquete serologique et epidemiologique sur la Fievre Q. Med. Mal. Infect. 13 (1983) 207-211 2. Edlinger, E.: Immunofluorescence serology - a tool for prognosis of Q fever. Diagn. Microbiol. Infect. Dis. 3 (1985) 343-351 3. Hannoun, c.: Personal communication
Dr. E. A. Edlinger, 25, rue Aubernon, F-06600 Antibes, France
Q Fever in France E. A. ED LINGER Institut Pasteur, National Center of Reference for Rickettsioses, Unite de Diagnostic Virologique et Rickettsiales, Paris, France
With 1 Figure
Abstract In France Q fever is a notifiable disease, but information could only be obtained from fragmental inquiries. Routine serologic examination of 75 901 sera during the years 1982-85 showed 430 Q fever positive sera (mean rate 0.57%). Our laboratory could confirm 135 cases of clinical Q fever. In the region of Dijon, 4.4% of the country population was seropositive, but among breeders 25% were positive. 36 persons (8%) among 245 employees of the departmental veterinary services were seropositive, some with very high titers, but without obvious clinical symptoms. It seems that infection by Coxiella burnetiiis still largely underestimated.
In France Q fever is a notifiable disease but the scarce informations gathered have no practical consequences. The reports are supposed to be established weekly, but clinicians omit to do so. Thus I can only present some fragmental results of inquiries to assess the frequency of Q fever in France. The reports of the laboratories contain only serologic results but no information on clinical data. Furthermore, the serologic technique still mostly used is the complement fixation test with all its drawbacks. In Table 1 the serologic results from 30 laboratories - mostly from northern France - are presented. No clinical data were available. It may be presumed that the blood samples were taken from patients with acute respiratory diseases (3). The mean rate of Table 1. Serologic results from 30 laboratories (Data from the Influenza Reference Center, Institut Pasteur, Paris) Year
Sera examined
Seropositives
1982 1983 1984 1985
14557 18404 19830 23110
65 90 137 138
Total
75901
430 (0.57%)
(0.45%) (0.49%) (0.69%) (0.60%)
Q Fever in France
27
positive reactions was 0.57%. Thus one might suppose that either clinical indication for specific Q fever serology was not given orland the test procedure was not sensitive enough. The serologic results on 2614 serum samples obtained by the National Reference Center for Rickettsioses are presented in Table 2. The mean rate of seropositives (titers > 1:20) by the indirect fluorescence antibody test (IFAT) which is the routine test in our laboratory (2), was 23.4%. The reason for the high rate of positives may be prior selection of the sera according to clinical and epidemiologic informations. Table 2. Serodiagnosis of Q fever in the National Reference Center for Rickettsioses Year
Sera examined
Positives
1982 1983 1984 1985
588 385 590 1051
24 37 149 402
Total
2614
612 (23.4%)
Among them clinically confirmed Q fever cases
(4.0%) (9.6%) (25.0%) (38.0%)
9 13 30 81
(37.5%) (35.0%) (20.0%) (20.0%)
133 (21.7%)
Acute Q fever could be confirmed for one fifth (21.7%) of the 612 seropositives. Confirmation was based on increasing antibody titers in paired sera or on two high titers (> 1:1280), but always together with consistent clinical data. From an epidemiologic point of view, the relative frequency of reported contacts with goats and sheep has to be mentioned. An outbreak of Q fever in a family has been puzzling: a French officer returned from French Guyana with his wife and two children to his parents in Normandy. Some days after his arrival, he became ill, was hospitalized, and Q fever was diagnosed. His wife became ill with Q fever one month later which was regarded as probably too late for infection in Guyana. The patient's father and his sister living in France got also Q fever. The mother experienced no illness and did not develop specific antibodies. The two children got seropositive but not sick. We assumed that C. burnetii was present in the dust of the luggage arriving from Guyana; however, it was the mother who cleaned the clothes of the arrived family, and she remained uninfected. Here human to human transmission cannot be excluded. Other information about Q fever in France may be derived from seroepidemic surveys of exposed populations. Such a study was made in 1980 in the Departement Cote d'Or (Dijon) (1). Results of this investigation are presented in Table 3. In a Table 3. Seroepidemiologic survey in the Departement Cote d'Or (Dijon) Group
Sera
Indirect Fluorescence Antibody Test (IFAT)
% positive
I
966
43
4,4
II
86
22
25.0
Group I = country people selected at random Group II = animal breeders
28
E.A.Edlinger
randomly selected country population (62% men and 38% women) 4.4% were seropositive, but among 86 animal breeders 22 (26%) were positive. In France all persons of the departmental veterinary services must be screened every year for Q fever infection by law. The Health Service of the Agricultural Social Security advised that the sera should be sent to the reference center. Yet only 13 of 89 rural departments sent the sera of their employees. These departments - except one (Vosges) - were in the western part of France, mostly in the northwest (see Fig. 1). Livestock in these regions consists mainly of bovines; there are only few sheep and rarely goats. Results are presented in Table 4. Eighty-nine persons (36%) were seropositive, among them 36 (15%) with a titer> 1:160. The follow-up study showed 15 persons with rising titers, and 4 with descending titers. Five persons had high titers. One man working in a slaughterhouse for 43 years had a titer of 1:5120 in 1983, but thorough clinical examination proved that he had been in perfect health; in 1986 his titer was 1:320. The second titer of 1:5120 is that of a woman, 25 years old; she was working for one year in the autopsy room of a veterinary laboratory, was seropositive in 1985 and got pregnant in 1986; she has been in perfect health so far. No case of clinically overt Q fever was reported.
Fig.1. Departements participating in serologic surveys. 17 Eure
18 Eure et Loire
19 Finistere Sud
Maine et Loire 53 Mayenne 56 Morbihan Garonne 86 Vienne 88 Vosges
37 Indrc et Loire
72 Sarthe
41 Loir et Cher
79 Deux-Sevres
49
82 Tarn et
Q Fever in France
29
Table 4. Survey of the Departmental Veterinary Services 1982-1985 Indirect Fluorescence Antibody Test (IFAT) Persons examined
negative
positive
< 1:80
> 1:160
245
156
89 (36%)
53 (21.6%)
36 (15%)
Follow-up, variation of titer and high titers Follow-up
Titer variations
Persons examined
1 year
2 years
3 years
4 years
< 1/160 ~ 1/160 High titers 4x 4x ;:: 1/640
245
129
62
26
28
15
4
5"
* One serum: 1:640; two sera: 1:1280; two sera: 1:5120
These rather scarce medical informations about Q fever in France regrettably cannot be supplemented with data from veterinary investigations since the rather small investigations performed applied questionable techniques and were intended to explain abortions and stillbirths among cattle. Anyhow, it seems that infection by C. burnetii in man occurs frequently in France and is largely underestimated. Acknowledgements. Prof. Claude Hannoun, Influenza Reference Center, Institut Pasteur, Paris, kindly supplied the data of 30 laboratories.
References 1. Chavanet, P., A. Pechinot, C. Nussbaum, and A. Portier: Enquete serologique et epidemiologique sur la Fievre Q. Med. Mal. Infect. 13 (1983) 207-211 2. Edlinger, E.: Immunofluorescence serology - a tool for prognosis of Q fever. Diagn. Microbiol. Infect. Dis. 3 (1985) 343-351 3. Hannoun, c.: Personal communication
Dr. E. A. Edlinger, 25, rue Aubernon, F-06600 Antibes, France