| [asymptomatic carrier state in creole goats and cattle after recovery from cowdria infection in guadeloupe]. | creole goats and cattle in guadeloupe can be carriers of cowdriosis (heartwater: cowdria ruminantium) after recovery for a period as long as 11 months in goats and 2 months in cattle. the carrier status was demonstrated by feeding amblyomma variegatum nymphs on recovered animals and the resulting adult ticks on susceptible goats. cowdria ruminantium was not detected permanently during the carrier status. | 1992 | 1301623 |
| the role of amblyomma variegatum in the transmission of heartwater with special reference to guadeloupe. | heartwater has been diagnosed in guadeloupe, marie-galante, and antigua; it induces important losses among goats and european or cross-bred cattle when local zebu creole are highly resistant to infection. amblyomma variegatum is the vector of the disease in the caribbean. the tick strain of martinique, occurring in that island that has apparently been disease-free since 1948, has not lost its ability to experimentally transmit the disease. in guadeloupe 97% of nymphs and nearly 100% of adults fe ... | 1992 | 1626882 |
| a cloned dna probe identifies cowdria ruminantium in amblyomma variegatum ticks. | heartwater, caused by cowdria ruminantium and transmitted by ticks of the genus amblyomma, is a constraint to ruminant animal production in sub-saharan africa. this rickettsial disease could spread from endemically infected areas of sub-saharan africa and certain caribbean islands to other countries, including the united states, in which amblyomma ticks exist. to detect c. ruminantium in tick vectors and animals, we made dna probes from c. ruminantium dna isolated from endothelial cell cultures. ... | 1991 | 1774264 |
| the occurrence of streptothricosis and its association with amblyomma variegatum ticks in st. lucia. | cattle, horses, sheep and goats in all areas of st. lucia were examined to ascertain the prevalence and distribution of streptothricosis on the island and to investigate its association with the occurrence of amblyomma variegatum ticks. although the disease was found to occur throughout st. lucia it was more prevalent and generally of a more severe form in areas where a. variegatum ticks are present. a tick control programme in the north of the island appeared to have resulted in a dramatic redu ... | 1991 | 1789020 |
| [sites of fixation of amblyomma variegatum ticks on their hosts in guadeloupe (french west indies)]. | the examination of 458 domestic and wild hosts of the tick a. variegatum allowed to collect 8,581 larvae, 646 nymphs, 685 adults in 9 different animal species and to determine their preferential attachment sites. in another survey on 15 goats and 5 cattle, 12,345 larvae, 2,111 nymphs and 4,625 adults were counted on the anatomic sites. immature ticks feed preferentially on the head, neck and limbs of birds, the limbs of mongoose and the limbs and ears of dogs, goats and cattle. adults feed only ... | 1991 | 1843828 |
| [ticks and hemoparasitic diseases in cattle in senegal. iv. the southern sudan area]. | the authors report on the results of an investigation on ticks and hemoparasitoses of cattle, sheep and goats in the south sudanian area of senegal. systematic routine dipping against ticks of cattle, 40 sheep and 40 goats was set during 15 months, with a view to determine the population dynamics together with an acurate localization of the different species concerned. the following parasites were collected from these ruminants: amblyomma variegatum, boophilus geigyi, hyalomma truncatum, h. m. r ... | 1990 | 2218038 |
| a mouse lethal dose assay for detection and titration of cowdria ruminantium (kwanyanga strain) in goats and ticks. | a mouse lethal dose assay was used to detect a mouse pathogenic strain (kwanyanga) of cowdria ruminantium, the etiological agent of heartwater in goats and ticks. the titer of the rickettsial organisms in goat blood was directly related to the febrile response of the goat and the rickettsia were undetectable after the fever subsided. the maximum rickettsial titer in goat blood was 10(3) mouse ld50 ml-1. cowdria-infected goat blood was shown to retain infectivity when held on ice for up to 2 h, b ... | 1989 | 2705290 |
| evaluation of the eradication program for amblyomma variegatum (acari:ixodidae) on puerto rico. | a cooperative effort between the united states department of agriculture, animal and plant health inspection service, veterinary services, the agricultural research service, and the department of agriculture, commonwealth government of puerto rico has been successful in eradicating amblyomma variegatum (fabricius) from the islands of puerto rico and vieques (an island municipality of puerto rico). application of acaricides to livestock and dogs at 14-day intervals for an 18-month period eliminat ... | 1989 | 2707108 |
| monitoring of naturally acquired and artificially induced immunity to amblyomma variegatum and rhipicephalus appendiculatus ticks under field and laboratory conditions. | the ability of rabbits, goats and cattle to acquire immunity to the ixodid ticks amblyomma variegatum and rhipicephalus appendiculatus was studied under laboratory and field conditions. rabbits were successfully immunized with crude salivary gland extract (sge) and midgut extract (me) obtained from flat or partly fed female r. appendiculatus ticks. the lowest numbers of larvae were produced by females fed on rabbits immunized with unfed midgut extract. similar reductions in larval production cou ... | 1989 | 2766896 |
| [effect of natural infestation by amblyomma variegatum ticks on the growth of creole cattle and goats]. | | 1988 | 3253862 |
| chemical control of the heartwater vectors. | this paper reviews available literature on the efficacy of acaricides against amblyomma hebraeum and other tick species, and presents information on tests done with registered chemicals in the laboratory. little published information is available on the efficacy of chemicals specifically against a. hebraeum. a host of formulations are registered for use as acaricides on cattle, sheep, and goats in south africa and thus, by implication, against this species. resistance has only been described to ... | 1987 | 3329335 |
| cowdria ruminantium: stability and preservation of the organism. | blood collected in either sodium heparin or disodium edetate vacutainers from febrile goats infected with 4 isolates of cowdria ruminantium and cryopreserved with 10% dimethyl sulphoxide at -70 degrees c and -196 degrees c was an effective stabilate to initiate heartwater infections in goats. a homogenized pool of whole amblyomma variegatum ticks in snyder's buffer, maintained at -196 degrees c, was used to infect a goat with c. ruminantium. liver and spleen collected from swiss mice infected wi ... | 1987 | 3448560 |
| epidemiology of heartwater in guadeloupe and in the caribbean. | at present, heartwater in the caribbean is known with certainty only on guadeloupe, marie galante and antigua; the first 2 islands are widely infected. the most important factors responsible for particular aspects of heartwater in guadeloupe are: cowdria ruminantium of high virulence. a very resistant cattle population (creole), not normally clinically affected. a fairly susceptible goat population (creole) (22% goats born in endemic areas die after experimental inoculation) which, fortunately, ... | 1987 | 3448572 |
| the reservoir status of goats recovered from heartwater. | experiments were conducted with creole goats and amblyomma variegatum ticks in guadeloupe to investigate whether it is possible to transmit cowdria ruminantium to susceptible hosts with nymphs fed in the larval stage on recovered goats. of 88 batches of larvae fed after the return of the goats' temperature to normal, or after challenge or immunosuppression, only the 9 batches of larvae fed during the febrile reaction, 2 batches applied 2 and 3 days respectively after recovery, and a single batch ... | 1987 | 3448574 |
| tick infestations on livestock in the yemen arab republic and their potential as vectors of livestock diseases. | a survey of ticks on cattle, camels, sheep, goats and donkeys in four different geographical locations of the yemen arab republic (yar) was carried out to provide more information on the possible risk of tick-borne diseases to imported exotic cattle included in the yar's plans for livestock development. the most abundant ticks were hyalomma spp. particularly on camels. ticks found on cattle included hyalomma spp., amblyomma variegatum, boophilus annulatus and rhipicephalus spp. in general with t ... | 1987 | 3603710 |
| prevalence of ectoparasites of small ruminants in nsukka, nigeria. | over a period of one year (january 1983 to december 1983), an investigation was mounted to determine common ectoparasitic infestation of small ruminants in selected farms in nsukka, nigeria. the species identified in goats included ctenocephalides canis, boophilius decolouratus and amblyomma variegatum lides while those recovered from parasitized sheep were ctenocephalides canis and damalinia ovis. out of a total of 148 sheep and goats examined for ectoparasites, 68 (45.95%) were infested. a fur ... | 1985 | 3836218 |
| ticks on livestock in st. lucia. | cattle, sheep, goats and horses were examined for ticks. over 95% of holstein cross-breeds, 28% of sheep (local mixed breeds) and 18% of goats (local mixed breeds) examined from 18 august to 4 september 1983 were infested with the southern cattle tick, boophilus microplus canestrini. about 90 and 17% of the horses examined were infested with the tropical horse tick, anocentor nitens neumann, and the tropical bont tick, amblyomma variegatum fabricius, respectively. the tropical bont tick was foun ... | 1985 | 4090245 |
| colonization and life cycle of amblyomma variegatum (acari: ixodidae) in the laboratory in puerto rico. | | 1984 | 6694178 |
| [ticks and hemoparasitoses of livestock in senegal. vi. the soudano-sahelian zone]. | the authors report the results of a study on ticks and hemoparasitoses among cattle, sheep and goats in the sudano-sahelian zone. during a period of 15 months, ticks were systematically removed from 40 cattle, 40 sheep and 40 goats in order to assess the population dynamics and determine more accurately the preferential sites of settlement of the different species. the following species were collected in ruminants: hyalomma truncatum, h. marginatum rufipes, rhipicephalus evertsi evertsi, rh. gui ... | 1994 | 7991897 |
| [ticks and hemoparasitoses in livestock in senegal. v. the northern guinea area]. | the authors report the results of a study on ticks and hemoparasitoses among cattle, sheep and goats in the north-guinean zone. during a period of 15 months, ticks were systematically removed from 40 cattle, 40 sheep and 40 goats in order to assess the population dynamics and to determine more accurately the preferential sites of settlement of the following different species collected from these animals: amblyomma variegatum, boophilus geigyi, hyalomma truncatum, h. marginatum rufipes, rhipiceph ... | 1993 | 8073170 |
| acaricides for eradication of the tick amblyomma variegatum in the caribbean. | the success of an eradication campaign against the tropical bont tick in the caribbean imposes the use of active acaricide compounds, if possible with residual activity, easy to apply and requiring few or no accessible water supplies and expensive application equipment. tests of in vitro susceptibility of tick strains from puerto rico and guadeloupe as well as observations of the impact of the current tick control campaigns conducted in some caribbean islands, seem to indicate that there is no p ... | 1993 | 8134652 |
| epidemiological studies on dermatophilosis in the caribbean. | dermatophilosis is one of the most important diseases of domestic ruminants in the caribbean islands where the clinical disease has been shown to be associated with the presence of the tick amblyomma variegatum. seroepidemiological studies were conducted to clarify the epidemiology of the disease in the region with a particular attention paid to the role of a. variegatum. a bank of 1300 cattle sera from the lesser antilles was screened by elisa for the presence of antibodies to dermatophilus con ... | 1993 | 8161379 |
| antibodies to cowdria ruminantium in mozambican goats and cattle detected by immunofluorescence using endothelial cell culture antigen. | endothelial cell cultures, established from bovine umbilical cord arteries and subsequently infected with cowdria ruminantium, were used as antigen in the indirect fluorescent antibody test. bovine sera (374) and caprine sera (388) collected in 6 provinces of mozambique were tested. overall, 30.4% of goat sera had antibodies to cowdria, and 43% of sera collected from cattle. north of the river save, where the tick amblyomma variegatum is highly prevalent, overall percentages of positive sera wer ... | 1993 | 8236490 |
| kinetics of male pheromone production by amblyomma variegatum (acari: ixodidae). | males of amblyomma variegatum (f.), when attached on their host, produce a pheromonal blend composed of methyl salicylate, ortho-nitrophenol, and nonanoic acid, which acts as an aggregation-attachment pheromone. using olfactometry assays, assays on hosts, and quantification of the compounds by capillary gas chromatography, the kinetics of pheromone production has been studied. males engorged for at least 10 d elicit attachment from most of the tested females. attractiveness of males for females ... | 1993 | 8271253 |
| detection of cowdria ruminantium by means of a dna probe, pcs20 in infected bont ticks, amblyomma hebraeum, the major vector of heartwater in southern africa. | a dna probe, pcs20, previously described for use in detection of cowdria ruminantium infections in amblyomma variegatum (the principal vector of heartwater) hybridized with c. ruminantium dna in organs of laboratory-infected a. hebraeum adult ticks (the major southern african vector of heartwater). the probe hybridized with c. ruminantium dna in 46/49 midguts from male ticks and 26/29 from females, thus indicating infection. corresponding salivary glands were less heavily infected, but infection ... | 1993 | 8432329 |
| tropical bont tick eradication campaign in the french antilles. current status. | the amblyomma variegatum eradication campaign was officially started in april 1994 in martinique and in guadeloupe, including its dependencies of marie galante, desirade and st martin. a budget of $10.5 and $5.9 million for guadeloupe and martinique, respectively, was initially (1991) calculated and considered necessary to achieve the program. however, eec, the most important donor, estimated that 75% only of this proposal was acceptable, on which it agrees to support a maximum of 50%. the balan ... | 1996 | 8784487 |
| heartwater in ghana: implications for control of ticks. | heartwater, an often fatal rickettsial disease of domestic ruminants transmitted by amblyomma variegatum ticks, ranks with the a. variegatum-associated skin disease dermatophilosis as a major constraint to the upgrading of livestock productivity in ghana. an epidemiological survey, using new diagnostic tests, is being carried out to determine the incidence and distribution of heartwater and other tickborne diseases in ghanaian cattle, sheep and goats. preliminary results from a longitudinal surv ... | 1996 | 8809994 |
| serological survey of heartwater relative to the distribution of the vector amblyomma variegatum and other tick species in north cameroon. | a study was carried out on the spatial and temporal distribution of amblyomma variegatum and other ticks infesting sheep and goats in northern cameroon. a serological survey of heartwater (cowdriosis) using a competitive elisa was concurrently carried out in the same flocks. a. variegatum was found to be the most predominant species accounting for 48.3% of all the ticks collected. other species identified included rhipicephalus sulcatus, r. lunulatus, r. turanicus, boophilus decoloratus, b. annu ... | 1997 | 9066062 |
| crimean-congo hemorrhagic fever in ticks (acari: ixodidae) and ruminants: field observations of an epizootic in bandia, senegal (1989-1992). | from 1989 to 1992, a longitudinal study of the relationships between different tick species and domestic ungulates in the transmission and amplification of crimean-congo hemorrhagic fever (cchf) virus was undertaken in the bandia area in senegal where the presence of the virus had been reported previously. an epizootic occurred in 1991-1992 and 22 strains of cchf virus were isolated from hyalomma marginatum rufipes koch, amblyomma variegatum (f.), rhipicephalus guilhoni morel & vassiliades, and ... | 1997 | 9379454 |
| attempts to feed amblyomma variegatum ticks on artificial membranes. | feeding jars were used to feed nymphs of amblyomma variegatum on blood of goats or cattle. sterile blood was collected daily or weekly (kept at 4 degrees c or frozen until use), with addition either of heparin alone or of heparin and antibiotics/fungicide or of heparin, adenosine triphosphate and glutathione. membranes were made of a thin (0.12-0.32 mm) film of silicone mastic. blood in the jars was replaced twice a day, and reached a temperature of 39 degrees c in a waterbath before it became a ... | 1998 | 9668493 |
| a review of heartwater and the threat of introduction of cowdria ruminantium and amblyomma spp. ticks to the american mainland. | heartwater, caused by the rickettsial agent cowdria ruminantium, is one of the most devastating livestock diseases in sub-saharan africa. in addition to domestic cattle, sheep, and goats, a variety of nondomestic species can acquire subclinical and clinical infections. recent epidemiologic findings that demonstrate a long-term host carrier state in domestic and wild ruminants, intrastadial transmission by the tick vectors (amblyomma spp.), vertical transmission of the agent from cows to their ca ... | 1998 | 9732023 |
| tick-borne rickettiosis in guadeloupe, the french west indies: isolation of rickettsia africae from amblyomma variegatum ticks and serosurvey in humans, cattle, and goats. | twenty-seven rickettsiae were isolated and/or detected from 100 amblyomma variegatum ticks collected on guadeloupe in the french west indies. in this study, the polymerase chain reaction procedure appeared to be more sensitive in detecting rickettsiae in ticks than the shell-vial technique. sequencing a portion of the outer membrane protein a-encoding gene showed that these rickettsiae appeared to be identical to rickettsia africae, a member of the spotted fever group rickettsiae recently descri ... | 1999 | 10403315 |
| tropical bont tick (amblyomma variegatum) eradication in the caribbean. the st. kitts experience. | the tropical bont tick (tbt) was first identified in st. kitts in 1978. initially, infestation was observed on cattle that developed a severe dermatitis. over a period of seven years, the tbt spread to most areas of the island, affecting cattle, sheep, and goats. the ruminant livestock population declined from, 6,000, 9,000, and 7,000 cattle, sheep, and goats, respectively, in 1984 to an estimated 400, 800, and 1,000, cattle, sheep, and goats in 1990. a project to control the tropical bont tick ... | 2000 | 11193641 |
| dermatophilus congolensis infection in goats in tanzania. | when goats in eastern tanzania were screened for skin diseases, dermatophilus congolensis was isolated from the skin lesions in 8 of 484 animals examined. in one severely affected case, the disease was also characterized by histological studies (gram stain, giemsa stain and routine he studies) and electron microscopy. the histological picture was characterized by hyperkeratosis, parakeratosis, acanthosis, folliculitis and an inflammatory cellular reaction involving the epidermis. gram stain and ... | 2001 | 11556616 |
| simultaneous detection of anaplasma and ehrlichia species in ruminants and detection of ehrlichia ruminantium in amblyomma variegatum ticks by reverse line blot hybridization. | the detection of anaplasma and ehrlichia species is usually based on species-specific pcr assays, since no assay is yet available which can detect and identify these species simultaneously. to this end, we developed a reverse line blot (rlb) assay for simultaneous detection and identification of anaplasma and ehrlichia species in domestic ruminants and ticks. in a pcr the hypervariable v1 region of the 16s ribosomal rna (rrna) gene was amplified with a set of primers unique for members of the ge ... | 2002 | 12243899 |
| development of a polyclonal competitive enzyme-linked immunosorbent assay for detection of antibodies to ehrlichia ruminantium. | a polyclonal competitive enzyme-linked immunosorbent assay (pc-elisa) is described for detection of antibodies to ehrlichia (cowdria) ruminantium by using a soluble extract of endothelial cell culture-derived e. ruminantium as the antigen and biotin-labeled polyclonal goat immunoglobulins as the competitor. for goats, the diagnostic sensitivity and specificity were both 100% with a cutoff of 80% inhibition (80 pi), with detection of antibodies for 550 days postinfection. for cattle, diagnostic s ... | 2003 | 12965926 |
| progress towards the eradication of amblyomma variegatum from the caribbean. | progress in the caribbean amblyomma program (cap) is reviewed since its inception in 1995 when regional eradication activities for amblyomma variegatum ticks were initiated using bayticol pour-on. technical achievements in the various islands were slow initially, and showed a wide diversity in attaining eradication targets. st. kitts, considered as a model program. eliminated the tropical bont tick (tbt) from most of the island in less than 3 years. however, the elimination of very low numbers o ... | 2002 | 14570141 |
| ehrlichia ruminantium seroprevalence in domestic ruminants in ghana; i. longitudinal survey in the greater accra region. | serum samples collected monthly over a 34-month period from cattle, sheep and goats in the greater accra region of ghana were tested for antibodies to ehrlichia (previously cowdria) ruminantium, the causative agent of heartwater, by polyclonal competitive elisa (pc-elisa). maternal antibodies, detected in about half of animals followed from under 1 month old, declined to negative levels within 2-4 months. amblyomma variegatum tick vectors were present on livestock in rural areas throughout the y ... | 2004 | 15145496 |
| some observations on the sero-prevalence of heartwater and tick infestation in zambian goats. | a survey was carried out to define the distribution of heartwater in goats that originated from six districts in communal grazing semi-arid areas of zambia. a total of 181 samples (40.1%) out of 451 serum samples from adult goats were positive for ehrlichia ruminantium antibodies after screening using indirect map-1b antigen elisa technique with statistically significant differences (p < 0.01) between the six districts. out of 1 036 adult goats examined for tick infestation, 105 were infested by ... | 2004 | 15373339 |
| point seroprevalence survey of ehrlichia ruminantium infection in small ruminants in the gambia. | using the map1-b enzyme-linked immunosorbent assay, we tested 1,318 serum samples collected from sheep and goats at 28 sites in the five divisions of the gambia to determine the ehrlichia ruminantium seroprevalence rates and to assess the risk for heartwater. about half (51.6%) of 639 sheep were positive, with seroprevalence rates per site varying between 6.9% and 100%. the highest seroprevalence was detected in the western part of the country (88.1% in the western division and 62.1% in the lowe ... | 2005 | 15817758 |
| genetic diversity of ehrlichia ruminantium in amblyomma variegatum ticks and small ruminants in the gambia determined by restriction fragment profile analysis. | understanding genetic diversity of ehrlichia ruminantium in host and vector populations is an important prerequisite to controlling heartwater by vaccination in traditional livestock systems in sub-saharan africa. we carried out a study in two phases: (i) evaluating the usefulness of the pcr-rflp assay based on the map1 coding sequence of e. ruminantium as a discriminatory tool to characterise genetic diversity, (ii) applying the technique to field samples from amblyomma variegatum ticks and sma ... | 2008 | 17646061 |
| a critical analysis of disease-associated dna polymorphisms in the genes of cattle, goat, sheep, and pig. | genetic variations through their effects on gene expression and protein function underlie disease susceptibility in farm animal species. the variations are in the form of single nucleotide polymorphisms, deletions/insertions of nucleotides or whole genes, gene or whole chromosomal rearrangements, gene duplications, and copy number polymorphisms or variants. they exert varying degrees of effects on gene action, such as substitution of an amino acid for another, shift in reading frame and prematur ... | 2008 | 18350334 |
| ixodid ticks infesting domestic goats in communal land areas of zimbabwe. | the purpose of this study was to determine the species spectrum of ticks infesting goats owned by resource-limited farmers in the state-owned communal land areas of zimbabwe. ticks were collected from goats at a single locality within each of 5 communal land areas, and a total of 14 ixodid tick species was recovered. the most numerous tick was rhipicephalus evertsi evertsi, which was present in all areas at each sampling, and a rhipicephalus sp. (near r. punctatus), which was most abundant on go ... | 2008 | 19244819 |
| innovative approach for transcriptomic analysis of obligate intracellular pathogen: selective capture of transcribed sequences of ehrlichia ruminantium. | whole genome transcriptomic analysis is a powerful approach to elucidate the molecular mechanisms controlling the pathogenesis of obligate intracellular bacteria. however, the major hurdle resides in the low quantity of prokaryotic mrnas extracted from host cells. our model ehrlichia ruminantium (er), the causative agent of heartwater, is transmitted by tick amblyomma variegatum. this bacterium affects wild and domestic ruminants and is present in sub-saharan africa and the caribbean islands. be ... | 2009 | 20034374 |
| ectoparasites are the major causes of various types of skin lesions in small ruminants in ethiopia. | ectoparasites are the major causes of skin lesions in animals. clinical, skin scraping examination, and histopathological studies were conducted to identify and characterize skin lesions in small ruminants caused by ectoparasites. mange mites, lice, sheep keds, and ticks were collected from the skin of affected animals for species identification. skin biopsies were collected from affected part of the skin and fixed in 10% neutral buffered formalin for histopathology. of 1,000 sheep and 600 goats ... | 2010 | 20195754 |
| survey of ixodid ticks in domestic ruminants in bedelle district, southwestern ethiopia. | a survey aimed at determining the status of ticks in cattle, sheep and goats in bedelle district (southwestern ethiopia) was carried out from november 2007 to april 2008. out of the total 330 animals examined, 314 (95.2%) were found to be infested (harbouring of at least a single tick). high rates of infestations were recorded across all three host species. factors like month of collection, age and sex of host species did not show significant association with infestation rates. a total of 5,507 ... | 2010 | 20563884 |
| tick-borne rickettsioses, neglected emerging diseases in rural senegal. | rickettsioses are one of the most important causes of systemic febrile illness among travelers from developed countries, but little is known about their incidence in indigenous populations, especially in west africa. | 2010 | 20856858 |
| rickettsia africae in amblyomma variegatum and domestic ruminants on eight caribbean islands. | we used pcrs with omp a primers to determine if spotted fever group rickettsiae occurred in amblyomma variegatum from 6 caribbean islands. positive amplicons were obtained from ticks from the u.s. virgin islands (9/18; 50%), dominica (39/171; 30%), montserrat (2/5; 40%), nevis (17/34; 50%), st. kitts (46/227; 20%), and st. lucia (1/14; 7%). sequences for a convenience sample of reaction products obtained from a. variegatum on st. kitts (7), american virgin islands (4), montserrat (2), and st. lu ... | 2010 | 21158615 |
| ehrlichia ruminantium in amblyomma variegatum and domestic ruminants in the caribbean. | the highly sensitive nested pcs20 polymerase chain reaction assay for ehrlichia ruminantium was negative on 506 amblyomma variegatum from caribbean islands where clinical heartwater has not been reported, mainly the united states virgin islands (18), dominica (170), montserrat (5), nevis (34), st. kitts (262), and st. lucia (17). positive results were obtained with positive controls (crystal springs strain) and a. variegatum from countries in africa where infections are endemic, mainly tanzania ... | 2011 | 21485394 |