Validation and comparison of three enzyme-linked immunosorbent assays for the detection of antibodies to Cowdria ruminantium infection.

Serological tests for Cowdria ruminantium infection have been hampered by low specificity. Here, an indirect ELISA based on purified antigen, a competitive ELISA using a recombinant major antigenic protein (MAP-1) and an indirect ELISA based on the MAP-1B region of the recombinant MAP-1 were compared. The tests were validated using 3000 sera of ruminants from 14 islands of the Lesser Antilles as well as sequential serum samples from 10 cattle, 17 goats and 10 sheep vaccinated with inactivated C. ruminantium in ISA 50 adjuvant and from 14 goats infected with a virulent culture supernatant. All tests detected significantly higher percentages of positives on Antigua, Guadeloupe and Marie-Galante, where C. ruminantium had been isolated before. Overall specificity calculated with sera from the other 11 heartwater-free islands was 98.1%, 98.5%, and 99.4% for the ELISA based on crude antigen, recombinant MAP-1 and MAP-1B, respectively. Sensitivities observed with sequential serum samples were similar for all tests. Tests based on recombinant antigens, especially the MAP-1B, showed improved specificity, suggesting their use for epidemiological studies in regions where the distribution of cowdriosis is unknown. In addition, the competitive ELISA is useful for studies in wildlife for which species-specific conjugates do not exist.

General review of the tick species which parasitize sheep and goats world-wide.

The paper lists the genera and species of ticks which occur world-wide in sheep and goats. The list is based on records documented in scientific ticks collections. Most ticks belong to Haemaphysalis, Rhipicephalus and Hyalomma genera which include many species with unclear taxonomic status and which are rather difficult to identify. The review points out that present knowledge on ticks which parasitize sheep and goats world-wide is still fragmentary.

[Parasite control and its effect on the environment]. / Parasitenbekämpfung und ihre Auswirkungen auf die Umwelt.

Chemical methods continue to be the primary means for control of parasites in medicine and veterinary medicine. Environmental concerns are raised mainly in the control of free living stages of parasites, intermediate hosts, vectors of diseases and in control of sanitary pests. Similarly, the type of application in case of sheep-dips and spraying of acaricides and insecticides in poultry houses against chicken mites is problematical. The now available bolus with ivermectin may cause a stronger impact on the cattle dung fauna and subsequent degradation of the dung as already known after injection and pour on.

[Serodiagnosis of Lyme borreliosis: development and evaluation of a test system for epidemiological studies in the dog]. / Serodiagnostik der Lyme Borreliose: Entwicklung und Bewertung eines Testsystems für epidemiologische Untersuchungen beim Hund.

The aim of the study was to develop and validate a serological test system for extended epidemiological investigations to which extend dogs were exposed to Borrelia burgdorferi. For this purpose, 121 samples of dogs which were suspect of an infection and submitted to the laboratory for serological testing, were investigated in an immunofluorescence test (IFT) and to different enzyme-linked immunosorbent assays (ELISA). Valuation of the ELISA systems was assessed in relation to the IFT. Sensitivity, specificity and predictive values were calculated for negative, positive and also borderline values. In the screening test all samples with a positive titre in IFT were judged positive. Samples negative in IFT showed negative results in the screening in only 86%. All samples positive in screening or of borderline value in IFT were again tested using a confirmatory ELISA. By this procedure a specificity of 100% and a sensitivity of 85% was calculated for samples with positive or negative IFT titres, respectively. Samples with IFT borderline titres (1:64 or 1:128) were judged negative in this ELISA in 80% and borderline in 16%. Checking of selected samples in an immunodot test confirmed the ELISA results. Sera being negative in ELISA showed also no specific reaction in this test. When considering the possibility of false positive reactions in IFT, rather high percentages of sensitivity and specificity could be found. Because all real positive samples could be detected using the confirmatory ELISA as a single test, there is no further need in epidemiological investigations to use the screening test. For specific problems the Western blot can be used.(ABSTRACT TRUNCATED AT 250 WORDS)

Simultaneous control of ticks and tsetse flies in Satiri, Burkina Faso, by the use of flumethrin pour on for cattle.

Treatments of 2000 cattle at monthly intervals with flumethrin pour on (1 mg active ingredient/kg b.w.) resulted in a rapid decrease of African Animal Trypanosomosis (AAT). After an initial curative treatment of the sentinel herd with diminazene aceturate (7 mg/kg b.w.) only positive cases were treated. Three applications of flumethrin were sufficient to reduce the prevalence of AAT to below 5%. Apart from a slight increase at the end of the first year the infection rate varied between 0 and 5%. A tsetse population disappeared from a heavily infested habitat after six treatments. The average tick infestation was 3-10 times lower than in a control site inspite of the repeated use of another acaricide. Between 3282 and 8624 animals were treated five times in the second year at intervals of about two months. 130 monoconical insecticide impregnated traps were deployed in habitats which were inaccessible for the cattle. The highest infection rate of the sentinel herd was 1.4%. Among another 150 eartagged cattle scattered over a district of about 1000 m2 the prevalence of AAT dropped to 4.8% at the end of the second year. Emphasis is put on an active and financial participation of the rural communities to ensure a viable campaign and good prospects of a taking over by local organizations once the external interventions have stopped.

[Epidemiological studies of the infection of ticks with borreliosis agents in small mammals from north Germany]. / Epidemiologische Untersuchungen zum Befall von Zecken mit Borreliose-Erregern von Kleinsäugern aus Norddeutschland.

In a two years study into the infestation of ticks with Borrelia burgdorferi from mice in North Germany 1330 mice out of 11 species could be examined. Altogether 508 mice showed to be parasitized by 1445 ticks belonging to three species of Ixodes. 777 I. ricinus from 334 mice could be tested for B. burgdorferi. In 66 ticks (8.5%) from 34 mice (10.2%) borreliae could be demonstrated. These discoveries came from 9 of 14 investigated forest regions in Lower Saxony.

[Studies of the ecology of some blood protozoa of wild small mammals in North Germany (author's transl)]. / Untersuchungen zur Okologie einiger Blutprotozoen bei wildlebenden Kleinsäugern in Norddeutschland.

In 1977 and 1978, 696 small mammals of 9 different species were surveyed for protozoal blood parasites. The following parasites were found: Hepatozoon sylvatici in Apodemus flavicollis, H. erhardovae and Trypanosoma evotomys in Clethrionomys glareolus, T. microti and Babesia microti in Microtus agrestis and T. croicidurae in Crocidura russula. H. erhardovae showed regularly high infection-rates (more than 70%) during all the years in 1977 and 1978. H. sylvatici was found only in 5.6% of the yellow-necked mice from March to October. T. microti and T. evotomys were predominately found in the time from July to October. The high infection-rates of the bank vole with B. microti from January to March and July to August indicate a bimodal type of seasonal dynamic. Under natural conditions M. agrestis was the only host for B. microti. Nymphs of the tick Ixodes ricinus were found to be able to transmit B. microti to Syrian golden hamsters (Mesocricetus auratus) in the laboratory.