Leptospirosis in urban wild boars, Berlin, Germany.We found antibodies to leptospires in 25 (18%) of 141 wild boars from Berlin (95% confidence interval confidence interval,
n a statistical device used to determine the range within which an acceptable datum would fall. Confidence intervals are usually expressed in percentages, typically 95% or 99%. 12-25). Seropositivity Seropositivity is the presence of a certain antibody in a blood sample. A patient with seropositivity for a particular antigen or agent is termed seropositive. was associated with chronic interstitial nephritis interstitial nephritis
Nephritis in which the interstitial connective tissue is chiefly affected.
Interstitial nephritis (odds ratio 10.5; p = 0.01), and leptospires were detected in kidney tissues. Wild boars represent a potential source for human leptospirosis leptospirosis (lĕp'təspīrō`sĭs), febrile disease caused by bacteria of the genus Leptospirae. The disease occurs in dogs, cattle, pigs, sheep, goats, and horses and is transmissible to humans. in urban environments.
Leptospira spp. are endemic to many domestic and wild animals WILD ANIMALS. Animals in a state of nature; animals ferae naturae. Vide Animals; Ferae naturae. , which may shed the pathogen in urine (1). Humans may acquire potentially fatal leptospirosis through contact with urine-contaminated water or soil. In Germany, [approximately equal to]50 cases of leptospirosis are reported each year, mostly related to recreational and residential exposures (2). Among wildlife species, rodents are considered to be the most important reservoirs for leptospirosis in rural and urban environments (3,4). Contact with water contaminated contaminated,
v 1. made radioactive by the addition of small quantities of radioactive material.
2. made contaminated by adding infective or radiographic materials.
3. an infective surface or object. with rodents' urine (usually inadequately treated sewage) is a well-known risk factor for leptospirosis. In wild boars (Sus scrofa) in Europe and the United States United States, officially United States of America, republic (2005 est. pop. 295,734,000), 3,539,227 sq mi (9,166,598 sq km), North America. The United States is the world's third largest country in population and the fourth largest country in area. , antibodies against Leptospira spp. serovar Pomona--the main serogroup that infects domestic swine--have been frequently detected (5,6). During the past decades, the population density of this game species has increased substantially (7,8). Subsequently, boar migration to urban areas and close contact with humans has been noted. At present, an estimated 5,000 wild boars live in urban and suburban areas of Berlin. Although boars are known to be susceptible to leptospirosis, data on the prevalence of the disease in synanthropic wild boars and the possible implications for human health are absent. Our objective was to assess the potential role of wild boars as a reservoir for leptospirosis in an urban environment. In addition, we examined their role in transmission of Leptospira spp. to city residents with occupational exposure to wild boars.
The survey was conducted in Berlin, which has an area of 891.7 [km.sup.2] and a population of 3.4 million. The study area is mostly urban (56%) and contains industrial, commercial, and residential buildings; the other portions are forest (17.9%), green space (14.5%), and water (6.6%). The southwestern study area partially merges with the adjacent city of Potsdam.
Serum and kidney tissue samples were collected from wild boars killed in the study area for population control during fall and winter 2005-06. Wild boars were categorized according to according to
1. As stated or indicated by; on the authority of: according to historians.
2. In keeping with: according to instructions.
3. age (determined by teeth; shoats <1 year, yearlings 1-2 years, adults >2 years), sex, and location of death. For antibody detection, microscopic agglutination test agglutination test
Any of various tests in which blood serum causes agglutination of bacteria or blood cells of a foreign type, used to determine infection and to identify pathogens and blood types. was conducted with a panel of 12 leptospiral serovars; a titer titer /ti·ter/ (ti´ter) the quantity of a substance required to react with or to correspond to a given amount of another substance. [greater than or equal to] 100 was considered positive (Table 1). For histologic his·tol·o·gy
n. pl. his·tol·o·gies
1. The anatomical study of the microscopic structure of animal and plant tissues.
2. The microscopic structure of tissue. investigation, the tissues were fixed in 10% formalin formalin /for·ma·lin/ (for´mah-lin) formaldehyde solution.
An aqueous solution of formaldehyde that is 37 percent by weight. ; embedded in paraffin; and stained with hematoxylin hematoxylin /he·ma·tox·y·lin/ (he?mah-tok´si-lin) an acid coloring matter from the heartwood of Haematoxylon campechianum; used as a histologic stain and also as an indicator. and eosin eosin /eo·sin/ (e´o-sin) any of a class of rose-colored stains or dyes, all being bromine derivatives of fluorescein; eosin Y, the sodium salt of tetrabromofluorescein, is much used in histologic and laboratory procedures. , Masson trichrome, or Warthin-Starry silver according to standard protocols. Chronic interstitial nephritis and resultant renal fibrosis, the characteristic lesions of renal leptospirosis in animals (9), were the criteria used to classify renal infection. Selected tissue samples were further studied by classic PCR PCR polymerase chain reaction.
polymerase chain reaction
Polymerase chain reaction (PCR) targeting the leptospiral outer membrane The outer membrane refers to the outside membranes of Gram-negative bacteria, the chloroplast, or the mitochondria. It is used to maintain the shape of the organelle contained within its structure, and it acts as a barrier against certain dangers. lipoprotein lipoprotein (lĭp'əprō`tēn), any organic compound that is composed of both protein and the various fatty substances classed as lipids, including fatty acids and steroids such as cholesterol. LipL32 (10). The amplification products were confirmed by direct sequencing.
To assess seroprevalence seroprevalence Immunology The proportion of a population that is seropositive–ie, has been exposed to a particular pathogen or immunogen; the seropositivity of a population is calculated as the number of individuals who produce a particular antibody divided among city residents, in April 2006 we enrolled 84 municipal hunters from Berlin. A standardized questionnaire was used to assess demographic information (age, sex), frequencies of contact with wild boars, and use of gloves during boar evisceration evisceration /evis·cer·a·tion/ (e-vis?er-a´shun)
1. removal of the abdominal viscera.
2. removal of the contents of the eyeball, leaving the sclera.
n. . Serum samples were collected from all hunters and analyzed as described above. Univariate odds ratios (OR), prevalence ratios (PR), and 95% confidence intervals (95% CI) were calculated by using SPSS A statistical package from SPSS, Inc., Chicago (www.spss.com) that runs on PCs, most mainframes and minis and is used extensively in marketing research. It provides over 50 statistical processes, including regression analysis, correlation and analysis of variance. 14 software (SPSS Inc., Chicago, USA). A p value <0.05 was considered significant.
During the 2005-06 hunting season, municipal hunters in the study area shot 294 wild boars. A total of 219 (74%) blood samples and 77 (26%) kidney specimens were collected from the boars. Of these, 78 (36%) blood samples had to be excluded from analysis because of insufficient quality (i.e., clotting). Of the 141 remaining serum samples, antibodies against pathogenic leptospires were found in 25 (18%) (95% CI 12-25). Of these 25 positive samples, 10 demonstrated cross-reactivity with antigens of other serovars. Among the samples without cross-reactivity, Leptospira spp. serovar Pomona (n = 6) and serovar Bratislava (n = 4) were most frequently identified (Table 1). Titers of Leptospira-positive serum samples varied from 100 through 800. Although not statistically significant, seropositivity was highest in animals from the southwestern part of the study area (Figure 1; Table 2). Seropositivity was also higher in adult animals (p = 0.02) but was unrelated to sex (p = 0.6). A total of 29 kidney specimens were examined histologically, 17 of which were from seropositive seropositive /se·ro·pos·i·tive/ (-poz´i-tiv) showing positive results on serological examination; showing a high level of antibody.
adj. boars. Of these 17, 15 (88%) showed moderate to severe chronic lymphoplasmacytic interstitial In a separate window. See interstitial ad.
(World-Wide Web) interstitial - A World-Wide Web page that appears before the expected content page. Interstitials can be used for advertising (intermercial, transition ad) or to confirm that the user is old enough to view the inflammation (Figure 2), compared with 5 (42%) from the 12 seronegative seronegative /se·ro·neg·a·tive/ (-neg´ah-tiv) showing negative results on serological examination; showing a lack of antibody.
adj. boars (OR 10.5; 95% CI 1.3-110.4; p = 0.01). Leptospires were detected by silver staining in 3 (30%) of 10 specimens from seropositive wild boars with chronic interstitial nephritis (5 of the 15 specimens were unsuitable for silver staining) and were confirmed by PCR in 2 of the leptospire-positive samples. However, among 84 municipal hunters (96% males, mean age 51 years) antibodies to leptospires were not detected. Sixty-one (73%) hunters shot > 10 wild boars per season. Of these, 51 (72%) used gloves, at least on occasion, compared with 6 of the 17 hunters (35%) who shot [less than or equal to] 10 boars per year (PR 2; 95% CI 1.2-3.4; p<0.05).
[FIGURES 1-2 OMITTED]
Our study describes a newly discovered urban focus of leptospirosis among wild boars in Berlin. The high frequency of porcine porcine /por·cine/ (por´sin) pertaining to swine.
pertaining to pig. See also hog (1), swine.
porcine circovirus 1
a nonpathogenic virus. Leptospira spp. serovars Pomona and Bratislava, the association of chronic interstitial nephritis with positive results of the microscopic agglutination test, and the demonstration of leptospires in kidney specimens all indicate that wild boars act as a maintenance host for Leptospira spp. in this urban area. A relatively high prevalence of leptospirosis was observed in the southwestern districts of the city, which are particularly rich in freshwater lakes intensively used for recreational activities by urban inhabitants
The game is based loosely on the concepts from SameGame. . The relevance of this finding to human health was demonstrated by a recent case of severe leptospirosis in this area of Berlin; the patient had had contact with fresh water, which was most likely contaminated by wild boar urine (11).
In contrast to findings of a study from Austria (12), we found no antibodies to leptospires in hunters. Although this finding may be related to the regular use of gloves by highly exposed persons, it also indicates that the transmission of leptospirosis from wild boars to humans, although present, occurs at a considerably low rate. However, the epidemic potential of infections like leptospirosis that have a basic reproduction number In epidemiology, the basic reproduction number of an infection is the mean number of secondary cases a typical single infected case will cause in a population with no immunity to the disease in the absence of interventions to control the infection. close to 0 (i.e., that are minimally transmissible transmissible /trans·mis·si·ble/ (trans-mis´i-b'l) capable of being transmitted.
Capable of being conveyed from one person to another. within human populations) is largely determined by the number of introductions from the animal hosts. Thus, among other contributing factors (e.g., human population expansion and encroachment, transmission to sympatric sym·pat·ric
Occupying the same or overlapping geographic areas without interbreeding. Used of populations of closely related species. populations of susceptible domestic animals), the ongoing increase in wild boar populations, and the shift from sylvatic sylvatic /syl·vat·ic/ (sil-vat´ik) sylvan; pertaining to, located in, or living in the woods.
found in the woods; occurring in animals of the forest. to synanthropic occurrence of this game species might lead to increased leptospirosis in humans.
From a public health perspective, surveillance of leptospirosis incidence, prevalence, and serovar distribution in wild boars and humans (especially in potential high-risk groups with recreational freshwater contact) is necessary to establish the direction and the significance of this newly discovered potential exposure route. Additionally, physicians and public health authorities should be aware that bodies of fresh water in areas populated pop·u·late
tr.v. pop·u·lat·ed, pop·u·lat·ing, pop·u·lates
1. To supply with inhabitants, as by colonization; people.
2. with wild boars may be contaminated with Leptospira spp., even if typical indicators, like rat infestations or contamination with sewage, are absent.
We thank Angelika Draeger for excellent technical assistance.
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animal disease - a disease that typically does not affect human beings of global importance. Lancet Infect Dis. 2003;3:757-71.
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in·tern or in·terne
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untamed; often used in the sense of having escaped from domesticity and run wild. pigs from New South Wales New South Wales, state (1991 pop. 5,164,549), 309,443 sq mi (801,457 sq km), SE Australia. It is bounded on the E by the Pacific Ocean. Sydney is the capital. The other principal urban centers are Newcastle, Wagga Wagga, Lismore, Wollongong, and Broken Hill. . J Wildl Dis. 1998;34:738-43.
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(7.) Schley L, Roper TJ. Diet of wild boar Sus scrofa in Western Europe Western Europe
The countries of western Europe, especially those that are allied with the United States and Canada in the North Atlantic Treaty Organization (established 1949 and usually known as NATO). , with particular reference to consumption of agricultural crops. Mammal Rev. 2003;33:43-56.
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Relating to or arising from many foci. interstitial nephritis in swine at slaughter. Can J Vet Res. 1989;53:290-4.
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(11.) Jansen A, Nockler K, Schonberg A, Luge luge (lzh), a type of small sled on which one or two persons, lying face up, slide feet first down snowy hillsides or down steeply banked, curving, iced chutes similar to those used in E, Ehlert D, Schneider T. Wild boars as possible source of hemorrhagic Hemorrhagic
A condition resulting in massive, difficult-to-control bleeding.
Mentioned in: Hantavirus Infections
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(12.) Deutz A, Fuchs K, Schuller W, Nowotny N, Auer H, Aspock H, et al. Seroepidemiological studies of zoonotic Zoonotic
A disease which can be spread from animals to humans.
Mentioned in: Zoonosis infections in hunters in southeastern Austria prevalences, risk factors, and preventive methods. Berl Munch munch - To transform information in a serial fashion, often requiring large amounts of computation. To trace down a data structure. Related to crunch and nearly synonymous with grovel, but connotes less pain.
Often confused with mung. Tierarztl Wochenschr. 2003;116:306-11.
Dr Jansen is a medical doctor and epidemiologist at the Robert Koch Institute, Berlin, Germany. His research interests include zoonoses Zoonoses
Infections of humans caused by the transmission of disease agents that naturally live in animals. People become infected when they unwittingly intrude into the life cycle of the disease agent and become unnatural hosts. , enteric enteric /en·ter·ic/ (en-ter´ik) within or pertaining to the small intestine.
1. Of, relating to, or within the intestine.
2. infections, and tropical infections.
Address for correspondence: Andreas Jansen, Department of Infectious Diseases infectious diseases: see communicable diseases. Epidemiology, Robert Koch Institute, Seestrasse 10, 13353 Berlin, Germany; email: JansenA@rki.de
Andreas Jansen, * Enno Luge, ([dagger]) Beatriz Guerra, ([dagger]) Petra Wittschen, ([double dagger double dagger
A reference mark () used in printing and writing. Also called diesis.
Noun 1. ]) Achim D. Gruber, ([double dagger]) Christoph Loddenkemper, ([section]) Thomas Schneider, ([section]) Michael Lierz, ([double dagger]) Derk Ehlert, ([paragraph]) Bernd Appel, ([dagger]) Klaus Stark, * and Karsten Nockler ([dagger])
* Robert Koch Institute, Berlin, Germany; ([dagger]) Federal Institute for Risk Assessment, Berlin, Germany; ([double dagger]) Freie Universitat Berlin, Berlin, Germany; ([section]) Charite, Campus Benjamin Franklin, Berlin, Germany; and ([paragraph]) Senate Department of Urban Development, Berlin, Germany
Table 1. Characteristics and titers of antibodies to leptospires of 25 seropositive wild boars, Berlin, fall/winter, 2005-06 Boar characteristics Sex ([dagger]) Age, y Place of death ([double dagger]) ([section]) M Adult 1 M Adult 1 F Adult 1 M Adult 1 M Yearling 1 M Adult 1 M Yearling 1 F Yearling 1 M Shoat 1 M Adult 2 F Shoat 2 F Yearling 3 F Adult 3 F Yearling 3 F Yearling 3 F Adult 3 F Adult 3 M Yearling 3 NK Yearling 4 F Shoat 4 F Adult 5 M Shoat 6 F Shoat 7 F Shoat 7 M Adult 7 Boar characteristics Leptospira spp. Serovar * Sex ([dagger]) Australis Autumnalis M - - M - - F - - M - 100 M - - M - - M - - F - - M - - M - - F - - F - - F - - F - - F - - F - - F 100 - M - - NK - - F - - F - - M - - F 400 - F - - M - - Boar characteristics Leptospira spp. Serovar * Sex ([dagger]) Bratislava Copenhageni M 100 - M 100 - F 100 - M 800 200 M 200 - M 200 - M 200 - F 100 - M - - M - - F - - F 100 - F - - F - - F 100 - F - - F 100 - M - - NK 100 - F - - F 100 - M 100 - F - - F - - M - - Boar characteristics Leptospira spp. Serovar * Sex ([dagger]) Grippotyphosa Pomona M - - M - - F - - M 200 800 M 100 100 M - 200 M 100 400 F - 100 M - 400 M - 100 F - 100 F - - F - 200 F 100 - F 100 400 F - - F - - M - 400 NK - - F - - F - - M - - F - - F - 800 M - - Boar characteristics Leptospira spp. Serovar * Sex ([dagger]) Pyrogenes M 100 M - F 100 M - M - M - M - F - M - M - F - F - F - F - F - F 100 F 100 M - NK - F 100 F - M 100 F - F - M 100 * Microscopic agglutination test panel included Leptospira interrogans serovars Australis, Autumnalis, Bataviae, Bratislava, Copenhageni, Hardjo, Icterohaemorrhagiae, Pomona, and Pyrogenes; Leptospira borgpetersenii serovar Tarassovi; and Leptospira kirschneri serovar Grippotyphosa. A titer of [greater than or equal to] 100 or above was considered positive. The highest titers are shown. ([dagger]) TNK, not known. ([double dagger]) Shoat, <1 y; yearling, 1-2 y; adult >2 y. ([section]) Numbers correspond to areas shown in Figure 1. Table 2. Locations of wild boars seropositive for Leptospira spp., Berlin, fall/winter, 2005-06' District ([dagger]) % Boars 95% CI 1. Zehlendorf/Wannsee 27 15-44 2. Spandau 10 3-29 3. Tegel/Reinickendorf 21 11-38 4. Pankow/Mahrzahn/Hellersdorf 22 6-55 5. Kopenick 9 2-38 6. Lichterfelde/Steglitz/Charlottenburg 16 1-27 7. Potsdam 18 6-41 Total 18 12-25 * Seropositivity determined by microscopic agglutination test. CI, confidence interval. ([dagger]) Numbers correspond to areas shown in Figure 1.