[Epidemiology of Ixodes-Borreliosis in Southern Germany]. / Zur Epidemiologie der Ixodes-Borreliose in Süddeutschland.

Intimate adaptation occurs between European strains of Borrelia burgdorferi and the local hard tick Ixodes ricinus. I. dammini, the important vector in USA, could not be infected experimentally with a strain of the lyme spirochete from Southern Germany. Other species of blood suckers are sometimes able to maintain uptaken spirochetes for a few days, but never to compensate the tick vector. Man seems to be a good host for B. burgdorferi but without epidemiological significance due to his poor vector role for ticks. The Ixodes-borreliosis is an anthropozoonosis. Well-known animal hosts for the three life stages of the tick are possible carrier hosts for B. burgdorferi as well. It has been established here for the first time in Europe that common wild-rodent species may be of some significance as hosts for the spirochete, as it is well-known in North America. Serological evidence shows, that dogs and grasing cattle in Southern Germany seem to play an important role in B. burgdorferi's outdoor circulation. 36 out of 72 dogs (= 50%) and 22 out of 66 cattle (= 33%) reacted significantly positive in the IFAT if local strains of B. burgdorferi were used as antigen. No serological cross reactions have been observed with Leptospira infections in dogs and cattles.

Microbiological findings in erythema (chronicum) migrans and related disorders.

In order to evaluate the virtual advantage of proving borrelial infection in dermatoses clinically diagnosed as erythema (chronicum) migrans (ECM), acrodermatitis chronica atrophicans (ACA) or lymphadenosis cutis benigna (LCB) by means of histological, cultural or serological trials, skin and serum samples obtained from altogether 99 patients suffering from these dermatoses were examined. Serum and--to some extent--skin specimens gained from healthy individuals (n = 36), patients with not tick bite associated disorders of skin, internal organs and nervous system (n = 121) were used as controls. In addition, serum specimens from patients enduring circumscribed scleroderma (morphea), n = 31, and sera of Bavarian forest workers (n = 211) were proven for the presence of borrelial antibodies. Using an indirect immunofluorescence assay with borrelial strains, propagated in inbred mice, as antigens, elevated IgM- and/or IgG antibody titers were found in 51 (84%) out of 61 ECM-, in 17 (100%) ACA- and in 2 (33%) out of 6 LCB-sera. Antibody titers decreased significantly after adequate antibiotic therapy. The groups in comparison yielded spirochetal serum antibodies as follows: Healthy individuals and patients with various diseases 7 out of 157 (4.5%), morphea patients 7 out of 31 (23%) and forest workers 71 out of 211 (34%). Borrelia burgdorferi was cultivated from 6 out of 32 skin and from 1 blood specimen obtained from ECM patients and from 1 out of 5 ACA skin specimens. Borreliae could also be detected in the blood of 3 out of 11 thymusaplastic nude mice after intraperitoneal implantation of ECM-tissue. More frequently than borreliae spindle-shaped bacteria resembling fusobacterium sp. were detected not only by in vitro cultivation of ECM and ACA skin samples, but also in the blood of thymusaplastic mice after implantation of ECM-tissue. By Warthin-Starry silver strain borrelia-like structures were detected in 9 out of 28 ECM, in 3 out of 12 ACA and in 1 out of 5 LCB skin specimens. Therefore in our experience serological examinations turned out to be the most productive diagnostic tool.

In vivo isolation and maintenance of some wild strains of European hard tick spirochetes in mammalian and arthropod hosts. A parasitologist's view.

Methods and results of isolation and experimental maintenance of Borrelia strains from indigenous Ixodes ricinus ticks are described. Out of 12 different proved rodent species and breeding variants the mongolian jird or gerbils (Meriones unguiculatus) offers most perfectly all the necessary qualities to produce a transitory not progressive microscopically apparent spirochetemia when splenectomized previously. Using a laboratory breed of Ixodes ricinus the occurrence of transstadial and transovarial transmission could be confirmed in the vector tick. Each developmental stage of ticks can be infected via blood ingestion on spirochetemic mammalian hosts but each stage can infect vice versa its blood donors equally well. Needle borne transmissions from gerbil to gerbil by i.p. administration of infected blood are particularly successful after previous deep-freezing and cryopreservation of the blood samples or tissue suspensions. Attempts are described to infect other tick species than I. ricinus, fleas and mites, respectively, via blood meal. The problem of the spirochetes perfect adaptation to the host will be discussed.

Reinfection in erythema migrans disease.

Two patients received oral penicillin for erythema migrans disease (EMD) in 1973 and 1977. Five and seven years later, respectively, they developed EMD for a second time after being bitten by ticks. The first and second erythema migrans lesions appeared in different places. Tests of sera evaluated for antibodies to Borrelia burgdorferi before (in one case), during and after the second episode of EMD remained negative (patient 1) or yielded an at least four-fold rise of IgG antibody titers, but did not become positive (patient 2). These cases provide evidence that reinfection in EMD may occur without a significant elevation of specific antibody titers.

[Histological studies of the gamogony and sporogony of Hepatozoon erhardovae in experimentally infected rat fleas (Xenopsylla cheopis)]. / Histologische Untersuchungen zur Gamogonie und Sporogonie von Hepatozoon erhardovae in experimentell infizierten Rattenflöhen (Xenopsylla cheopis).

We studied, under experimental conditions, the life cycle of Hepatozoon erhardovae in the tropical rat flea, Xenopsylla cheopis, light microscopically on coloured semi-thin sections. Fleas killed and prepared on the day of infection show stomachs filled with mice erythrocytes. Some monocytes are parasitized or show empty envelopes of gametocytes. The latter perforate the wall of the stomach, leaving behind empty parasitophorous vacuoles, and they migrate to the fat-body cells of the flea where they differentiate sexually and where they stay during the whole of their further sexual development. On days 2 and 3 post infection (p.i.) microgametes were observed with one flagellum each, as well as macrogametes in one and the same host cell. Fertilization is induced by gametogamy. During the various divisions of the nuclei on the days 8-12 p.i. droplet-like evaginations are formed on the pellicle of the oocyst from the peripherical chromatin condensations. Between days 12 and 14 p.i. the sporoblasts develop while the oocysts diminish in size. Between days 18 and 20 p.i. 16 sporozoites and a large residual body are differentiated in each sporoblast and surrounded by the sporocyst wall. The oocyst wall is preserved and forms sporocyst balls that are set free when the flea abdomen is pressed. The flea thus presents a highly infective vector; the intermediate host is infected after eating the flea.

[The Elba triad: harara, light dermatoses, leishmaniasis. The ecological background]. / Elba-Trias: Harara, Lichtdermatosen, Leishmaniasis Der ökologische Hintergund.

A report is given on a travel to Elba, the largest island of the Tuscany archepelago (Italy) and a holiday place preferred by German speaking tourists. In the last years some cases of visceral leishmaniasis and oriental sores, respectively, were introduced to Germany from this island. The geoecological background of this development was investigated. Reproduction and spread of the most abundant sandfly species Phlebotomus (Laroussius) perniciosus favour ruinous buildings, actually used as animal shelters sometimes in the immediate vicinity of new tourist bungalows. A typical allergic response upon sandfly bites occurs in almost all of the newcomers. This skin irritation is wellknown as urticaria multiformis endemica of Harara. Local people and tourists connect this itching disorder with certain types of sun trauma and do not take notice of their real etiology. Cortisone treatment in severe cases may facilitate the start of simultaneously transmitted leishmaniasis. The possible epidemiological role, which the dog travelling to southern countries in connection with leishmaniasis plays, is considered.

Evaluation of antigens for the serodiagnosis of kala-azar and oriental sores by means of the indirect immunofluorescence antibody test (IFAT).

Antigens and corresponding sera were collected from travellers with leishmaniasis returning to Germany from different endemic areas of the old world. The antigenicity of these Leishmania strains, which were maintained in Syrian hamsters, was compared by indirect immunofluorescence (IFAT). Antigenicity was demonstrated by antibody titres in 18 sera from 11 patients. The amastigotic stages of nine strains of Leishmania donovani and four strains of Leishmania tropica were compared with each other and with the culture forms of insect flagellates (Strigomonas oncopelti and Leptomonas ctenocephali). Eighteen sera from 11 patients were available for antibody determination with these antigens. The maximal antibody titres in a single serum varied considerably depending on which antigen was used for the test. High antibody levels could only be maintained when Leishmania donovani was employed as the antigen, but considerable differences also occurred between the different strains of this species. The other antigens were weaker. No differences in antigenicity between amastigotes and promastigotes of the same strain were observed. It is important to select suitable antigens. Low titres may be of doubtful specificity and are a poor baseline for the fall in titre which is an essential index of effective treatment.

Primary and secondary skin leishmaniasis in experimental rodent hosts.

Pathological observations are described from experimental infections of Syrian hamsters, nude mice and bank voles with different Leishmania strains isolated from travellers returning to Germany from endemic areas. The main purpose of the paper was to demonstrate the changing patterns of parasite predilection sites within appropriate experimental animals. Despite the occasionally-occurring episodes of altered predilection sites the principal organotropic behaviour of given Leishmania strain was remarkably constant in in vivo passages. Here a genetic background seems evident which justified a legal use of such host related properties in taxonomic considerations. It was noted that humans appear to be poor indicators of the micro-ecological abilities of Leishmania spp.

[The diagnosis of visceral leishmaniasis (carried in) (author's transl)]. / Zur Diagnose ein-geschleppter viszeraler Leishmaniosen (Kala-Azar).

Five cases of Kala-Azar carried in from the Mediterranean area between May 1977 and March 1979 suggest that in this age of mass tourism these diseases, considered by us as rarities until now, may become more common. In all cases considerable difficulties in diagnosis were first encountered. Serology was always indicative, the indirect fluorescence antibody test (IFAT) being found very reliable. In 4 of the 5 cases the identity of the pathogen was previously established by different methods.

Babesia microti: morphology, distribution and host relationship in Germany.

A short review has been given about recent studies on Babesia microti in natural animal host's near Munich (Southern Germany). An infected area has been studied in order to elucidate the outdoor relationship between the local strains and their preferred hosts, the European field vole Microtus agrestis. The seasonal variation of the parasites prevalence in voles shows a rise in the early summertime (71% of the catches infected). Roundish forms predominate in the erythrocytes. Multiplication never takes place by binary fission, but in "Maltese cross" form or budding-like. Normally the parasite is enveloped with a simple elementary membrane only, as shown by electron microscopy. The arthropod host is still not identified, infections of human beings not observed. This is the first finding and full description of B. microti in Germany.

Pathomorphologic findings in short-tailed voles (Microtus agrestis) experimentally-infected with Frenkelia microti.

Following oral infection of Microtus agrestis with sporocysts of Frenkelia microti, transient focal necrosis and cellular infiltrations in the liver, hyperplasia of lymphoid organs, and inflammatory infiltrations in the heart, pulmonary veins, skeletal muscles and brain occurred during the first asexual multiplication period of the parasite in the liver. Frenkelia cysts were first observed in the brain 23 days after infection.

[Life cycle of Frenkelia. IV. Pathomorphological findings in the organs of experimentally infected bank voles]. / Beiträge zum Lebenszyklus der Frenkelien. IV. Pathomorphologische Befunde an den Organen experimentell infizierter Rötelmäuse.

In 1975 the buzzard (Buteo buteo) was found to be the final host of Frenkelia clethrionomyobuteonis. After this discovery it became possible to investigate systematically the pathomorphology of the infection in the intermediate host, the bank vole (Clethrionomys glareolus). Fifty bank voles were infected orally with a suspension of sporocysts recovered from the faeces of experimentally infected buzzards. Each rodent receive 7000 sporocysts. Six controls each were given a faecal suspension from a non-infected buzzard. The voles were killed between 1 and 140 days after infection and examined histologically. Between the 5th and 8th day of the infection during the schizogonic multiplication of the parasite a focal necrosis of liver cells and of the liver parenchyma is observed followed by a reversible resorptive inflammation associated with siderophagia and the occurrence of giant cells. The spleen was spodogenously enlarged up to twice its normal size. There also was haemosiderosis of the bone marrow, the liver and the spleen up to 25 days after infection. At the same time the erythropoiesis in the bone morrow, the spleen and in the lymph nodes increased; there also was a lymphoid hyperplasia in spleen and lymph nodes. About 10 days after infection a reversible infiltration with lymphocytes and plasma cells developed in the liver, heart and brain. This infiltration was again detectable as perivascular and meningeal reactions in the brain after the 49th day after infection. The second asexual multiplication of the parasite was seen histologically in the grey and white matter of the central nervous system after the 18th day of infection. The developing cysts increased in size continuously thereby compressing the surrounding nervous tissue. Disseminated focal necrosis with resorptive inflammatory components was prominent in the parenchyma of the brain after the 49th day of infection. It was possible to differentiate between damage in single organs and systemic pathological lesions. The lesions in single organs were directly connected with the development of parasitic stages in the liver (schizonts) and in the brain (cysts). The generalized lesions occurred in the haemopoietic system after an impairment of the blood during the first asexual multiplication. They also occurred in the immunocytic systems after the first and during the second asexual multiplication and during the relatively late cystic phase of the parasite in the brain. The pathogenesis of the disintegration of blood cells is not clear. The immunocytic reaction can be considered an immunological response of the host against the parasite. The effect of the development of the cysts on the function and structure of the central nervous system is expected to lead to an increasing impairment of the motility of the intermediate host.