Outbreak Of Babesiosis Research Articles

Detection of Babesia spp. in High Altitude Cattle in Ecuador, Possible Evidence of the Adaptation of Vectors and Diseases to New Climatic Conditions.

Background: Babesia species are intraerythrocytic protozoa, distributed in tropical and subtropical areas of the world, causing anemic diseases in many animals, including cattle. This disease, called babesisosis, is transmitted from one animal to another through ticks (Tick Borne-Disease or TBD). On the other hand, Ecuador has a tropical climate that allows the development of the vector Rhipicephalus microplus, and therefore favors the transmission of Babesia spp. in cattle. Methods and principal findings: We determined the presence of Babesia spp. by PCR using 18s ribosomal gene as target (18s PCR) in 20 farms in the area of El Carmen (zone below 300 m above sea level) and 1 farm in Quito (2469 m.a.s.l.). In addition, we analyzed parameters such as age, sex, and packed cell volume (PCV) as explanatory variable associated with the disease. Results: The 18s PCR test showed that 18.94% (14.77% Babesia bovis and 4.17% Babesia bigemina) and 20.28% (14.69% B. bovis and 5.59% B. bigemina) of the cattle were positive for Babesia spp in farms sampled in El Carmen and in Quito, respectively. Age influenced the presence of animals positive for Babesia spp., but sex and PCV did not. The phylogenetic analysis of sequences showed 4 isolates of B. bovis and 3 isolates of B. bigemina in the 2 study zones, with similarities between 99.73 and 100% with other sequences. One B. bovis isolate was similar in the zone of El Carmen and Quito. Conclusion and significance: This work is the first molecular characterization of B. bigemina and B. bovis in Ecuador, and it is also the first evidence of Babesia spp. in cattle in the area of Quito at an altitude of 2469 m.a.s.l., being the highest altitude reported for animals with babesiosis and for the tick R. microplus. Climatic factors as well as mobility of tick-carrying animals without any control allow the presence of Babesiosis outbreaks in new geographical areas.

Challenges in Tick-Borne Pathogen Detection: The Case for Babesia spp. Identification in the Tick Vector.

The causative agents of Babesiosis are intraerythrocytic protozoa of the genus Babesia. Babesia parasites are present around the world, affecting several mammals including humans, pets and livestock, hence its medical and veterinary relevance. Babesia spp. detection in its invertebrate host is a main point in understanding the biology of the parasite to acquire more knowledge on the host–Babesia–vector interactions, as increasing knowledge of the Babesia lifecycle and babesiosis epidemiology can help prevent babesiosis outbreaks in susceptible mammals. The aim of the present review is to highlight the newest findings in this field, based on a bibliographic compilation of research studies recently carried out for the detection of the main Babesia species found in tick vectors affecting mammalian hosts, including the different tick stages such as adult ticks, larvae, nymphs and eggs, as well as the detection method implemented: microscopic tools for parasite identification and molecular tools for parasite DNA detection by conventional PCR, nested-PCR, PCR-RFLP, PCR-RLB hybridization, real time-PCR, LAMP and RAP assays. Although molecular identification of Babesia parasites has been achieved in several tick species and tissue samples, it is still necessary to carry out transmission experiments through biological models to confirm the vectorial capacity of various tick species.

The Spatial Distribution of Dermacentor Ticks (Ixodidae) in Germany-Evidence of a Continuing Spread of Dermacentor reticulatus.

In Europe, two tick species of the genus Dermacentor occur, Dermacentor marginatus and Dermacentor reticulatus. When the spatial distribution of both species in Germany was studied comprehensively for the first time in 1976, D. marginatus populations were recorded along the Rhine and Main river valleys in southwestern Germany, while D. reticulatus was very rare. In the last 50 years, however, a considerable range expansion of D. reticulatus has been noted in several European countries. To assess the current distribution of Dermacentor spp. in Germany, citizens were asked to send in ticks suspected to belong to the genus Dermacentor or that were of “unusual” appearance. From February 2019 until February 2020, 3,902 Dermacentor ticks were received in total. Of those, 15.48% (604/3,902) were identified as D. marginatus and 84.24% (3,287/3,902) as D. reticulatus, while 11 specimens could not be identified to species level. The majority of D. reticulatus specimens was collected from dogs (1,212/2,535; 47.12%), while D. marginatus was mostly collected from horses (184/526; 34.98%). Our results confirm that the adults of both Dermacentor species are active all year round. D. reticulatus specimens were sent in from all federal states except the Free and Hanseatic City of Hamburg, while D. marginatus specimens were only received from locations in southwestern Germany. Overall, data obtained from this citizen-science study show that D. reticulatus has significantly expanded its range, especially in northern Germany. Regarding D. marginatus, new locations northwest of the previous range were detected, although the distribution has remained rather stable as compared to D. reticulatus. The spread of D. reticulatus, the vector of Babesia canis, is of major importance for veterinarians and dog owners in terms of canine babesiosis outbreaks or endemization in hitherto B. canis-free areas. Thus, veterinarians and veterinary students need to be informed about the new situation to be able to give adequate advice to dog owners on the extended D. reticulatus range and appropriate control measures.

Validation of an indirect ELISA using recombinant proteins as antigen to identify animals exposed to Babesia bigemina.

The objective of this study was to instrument a serological assay for the epidemiological diagnosis of bovine babesiosis in Mexico, using the Babesia bigemina recombinant protein RAP-1 (rRAP-1α) as antigen. rRAP-1α, r12d3 and rGP45 were the three recombinant antigens initially tested. Based on the highest titres obtained in the indirect ELISA (iELISA) with the positive control serum, using similar antigen concentrations, rRAP-1α was selected for further use. The diagnostic sensitivity and specificity rates estimated for the iELISA with rRAP-1α as antigen were 89.9% and 86.5%, respectively, while for the Indirect Fluorescent Antibody Test (IFAT), the gold standard assay, the sensitivity was 86.66% and the specificity was 95%. The ĸ agreement value determined was 0.52, indicating a moderate agreement between the iELISA and IFAT assays. The instrumented iELISA with rRAP-1α as antigen shows an excellent specificity rate and an acceptable sensitivity that allows for the detection of antibodies to B.bigemina in cattle naturally exposed to the vector tick Rhipicephalus microplus. By using the iELISA-rRAP-1α, along with an iELISA with recombinant Merozoite Surface Antigen (rMSA-1) for antibody determination against Babesia bovis in the serum samples collected from cattle at 'La Posta' experimental station in Mexico, a seroprevalence of 20.3% was estimated for B.bigemina and 19.4% for B.bovis, while 36.89% of samples were positive for both Babesia species. The iELISA test promises to be a safe and low-cost type of diagnosis available to cattle producers in Mexico and would facilitate the definition of herd immunity status to implement measures of control adapted for the prevention of bovine babesiosis outbreaks.

Risks of cattle babesiosis (Babesia bovis) outbreaks in a semi-arid region of Argentina

The epidemiology of Babesia bovis was studied in terms of enzootic stability/instability and husbandry and abiotic factors influencing B. bovis transmission rate in northeastern Santiago del Estero province, Argentina. The area is of limited suitability for its only vector in Argentina, the tick Rhipicephalus microplus. The proportion of calf herds in a state of enzootic stability/instability to B. bovis was determined and husbandry practices and abiotic factors associated with variations in B. bovis transmission rates were explored using a cross-sectional observational study design. Daily probability of infection (inoculation rate, h) with B. bovis was calculated from age-specific seroprevalence via ELISAi in 58 herds of 4.5–8.5-month-old calves. Herds were considered to be in enzootic instability (EI) when h < 0.005, and therefore inferred to be at risk of babesiosis outbreaks. Husbandry practices associated with differences in B. bovis transmission were analyzed using generalized linear models. Sixty-two percent of herds were found to be in an EI situation for B. bovis. Calves raised exclusively on permanent pastures –where higher cattle density is achieved– were exposed to higher B. bovis inoculation rates (h = 0.0063, 95% CI 0.0032-0.0123) than those reared under forage combinations (h = 0.0024, 95% CI 0.0011-0.0051) (P = 0.05). In addition, calves from herds located in the area of intermediate suitability for R. microplus development were more likely to become infected with B. bovis (h = 0.0067, 95% CI 0.0037-0.0121) than those reared in the ecologically unfavorable area for the vector (h = 0.0023, 95% CI 0.0010-0.0049) (P = 0.02). Neither the frequency of treatment with acaricides nor the use of long-acting acaricides to control R. microplus influenced the inoculation rate (P = 0.99 and P = 0.26, respectively). This result indicates that current R. microplus control schemes are not effective in reducing B. bovis transmission. Enzootic instability still prevails in the study area despite the drastic changes occurred in cattle production system. However, 38% of herds did reach enzootic stability; therefore, a specific epidemiological status cannot be assumed at a regional level. Yearly determination of the immunological status of each calf cohort is considered a proper approach to decision-making in vaccination against B. bovis.

PCR Based Approach for Detection of Bovine Babesiosis in Suspected Carrier Cattle and Vector Ticks in Sri Lanka

Purpose: Cattle recovered from clinical babesiosis become carriers for a certain period posing a threat of transmitting the disease to the entire herd. Diagnosis of carrier cattle is important for preventing outbreaks of babesiosis. The objective of the present study therefore, was to establish a sensitive rapid detection method for bovine babesiosis in suspected carrier cattle using nested PCR (nPCR). Research Method: Accordingly, 30 blood samples and ticks were collected from suspected carrier cattle representing two bio-climatic zones of Sri Lanka. Blood samples were analysed by both microscopically and nested nPCR methods for detection of bovine babesiosis. Further ticks were analysed for morphological idenfication using micrscopy and for babesiosis with nPCR. Findings: 47% (14/30) among the investigated samples became positive for the babesia infection with light microscopy, while nPCR analysis diagnosed 90% (27/30) as positive. This indicates that, 43% (13/30) of the animals which appeared to be healthy through routine light microscopical diagnosis were in fact carriers posing a major threat to the healthy herd. Further, according to the results of nPCR, 22% (6/27) of the blood samples were positive only for Babesia bovis infection, 11% (3/27) only for Babesia bigemina infection and 67% (18/27) for mixed infection with both parasites. The dominant tick vector isolated from both zones was Rhiphicephalus microplus. Out of the examined ticks, 21% (5/24) were positive for Babesia bigemina infection. Research limitations: Since the sample size from all sites of both climatic zones were uneven and small, data could not be analysed for statistical significance. Originality/Value: However, the results from this study indicate that nPCR provides a sensitive screening method to detect bovine babesiosis compared to the conventional microscopic analysis.

Clinical outbreak of babesiosis caused by Babesia capreoli in captive reindeer (Rangifer tarandus tarandus) in the Netherlands

From a herd of captive reindeer (Rangifer tarandus tarandus) consisting of two males and seven females with five calves, three calves were diagnosed on post mortem examination with a Babesia capreoli infection. The diagnosis was indicated by PCR and when the other reindeer were examined two adult females and a one-year-old male were Babesia-positive. Molecular characterization of the 18S rDNA of the parasite showed complete identity with known B. capreoli sequences. Ixodes ricinus has been demonstrated to be a competent vector for B. capreoli from infected roe deer (Capreolus capreolus), the natural host of B. capreoli.The B. capreoli infection in these reindeer may have been transmitted by infected ticks (Ixodes ricinus) originating from roe deer living in the forest and meadows surrounding the enclosure.

Diagnosis and management of bovine babesiosis outbreaks in cattle in Punjab state.

Aim:The aim of the present study was to diagnose severe outbreaks of bovine babesiosis in Punjab state, in the year 2015 and to suggest control and preventive measures to animal owners.Materials and Methods:Mortality of animals was recorded in two cattle herd comprising a total of 465 cattle in Sangrur (n=125) and Faridkot (n=340) districts. There was a history of purchase of animals at one farm. 23 blood samples were collected from diseased (n=15) and healthy animals (n=8) for hematological analysis, parasitological, and polymerase chain reaction (PCR)-based diagnosis. Ticks were also collected from animals for identification.Results:Out of 465 cattle at risk, 28 were critically ill and 14 died of disease with morbidity, mortality, and case fatality rate of 6.02%, 3.01%, and 50.00%, respectively. Clinical signs and necropsy findings were suggestive of babesiosis. Ticks collected from both the outbreaks were identified as Rhipicephalus (Boophilus) microplus. Thin blood smears from infected animals (especially with clinical sign of hemoglobinuria) were found positive for Babesia bigemina organisms; however, molecular diagnosis (PCR) further confirmed the disease. Animals were successfully treated with diminazene aceturate, hematinics, and antipyretics.Conclusions:Two fatal outbreaks of babesiosis in cattle were diagnosed with application of conventional parasitological, hematological, and molecular diagnostic techniques. PCR was found to be far more sensitive in detecting the disease, especially in latent infections. Animal owners were advised to follow quarantine measures before mixing new animals in the herd and strategic acaricidal treatments for effective tick control.

Molecular and serological prevalence of Babesia bovis and Babesia bigemina in water buffaloes in the north region of Brazil

Bovine babesiosis is a tick-borne disease caused mainly by Babesia bovis and Babesia bigemina, which are associated to considerable economic losses in cattle herds worldwide. Approximately 60% of buffalo herds in South America are located in Northern Brazil. Little is known about the impact of babesiosis on buffalo herds in Brazil. The present work aimed to verify the occurrence of B. bovis and B. bigemina in 542 water buffaloes in the state of Pará, Northern Brazil, using molecular and serological techniques. The percentage of seropositive animals for B. bovis and B. bigemina was 41.2% and 19.0%, respectively, by ELISA. B. bovis and B. bigemina DNA were detected in 15 and 16% of sampled buffaloes, respectively. A high correlation (Kappa index of 0.9) between serological and molecular tests suggests that the combination of the utilized techniques in the present study is suitable for babesiosis diagnosis in an endemic unstable area. Significantly difference of positivity for serological and molecular assays was verified to localities and reproductive status of sampled animals, but not between buffalo breeds. The immune status of sampled buffaloes associated to the circulation of babesiosis agents in sampled population suggests that the studied area is at risk to clinical babesiosis outbreaks. Furthermore, this study demonstrated that this region can be classified as endemically unstable.

Diagnostic methods used to monitor an outbreak of babesiosis (Babesia bovis) in a herd of feral cattle in New Caledonia

In December 2007, Babesia bovis was introduced to New Caledonia through the importation of cattle vaccinated with a live tick fever (babesiosis and anaplasmosis) vaccine. Medical measures, acaricide and antiprotozoal treatments, and quarantine restrictions were implemented with success on all the farms involved, but the disease spread to one of the neighbouring properties where feral cattle were present. To circumscribe and eliminate this outbreak, the authorities decided to slaughter all animals on the neighbouring property. To monitor the spread of babesiosis in naïve cattle and to compare the usefulness of PCR, ELISA and brain smear for disease detection in monitoring this outbreak. Blood and brain samples of slaughtered animals were analysed over time throughout the eradication campaign using serology, PCR and brain smears. In addition, field numbers of Rhipicephalus microplus tick larvae were assessed and Babesia infection of the larvae analysed using PCR. This study showed the natural spread of babesiosis in a naïve herd without pharmacological control measures. Prevalence reached 80% within a year of introduction. ELISA and PCR tests performed similarly in detecting disease in cattle and both were superior to brain smears. Nevertheless, specific tests or combinations of tests may be preferable, depending on the specific requirements of any future disease situation. In cattle, ELISA and PCR appear to be suitable tools for monitoring the evolution of a babesiosis outbreak, with brain smears as a useful adjunct. PCR was not suitable for detecting infection in tick larvae.

Clinical management of an outbreak of Babesiosis in a herd of cattle: A Case Report

Eight Friesian-Sahiwal cattle aged between 8 months and 1 ½ years old of both sexes weighing between 100 and 170 kg were infected. The cattle were managed semi intensively. Two weeks before presentation to the University Veterinary Hospital, Universiti Putra Malaysia, two calves died out of 10. The 8 remaining cattle were presented with chief clinical signs of pale mucous membrane, jaundice, and increased respiratory rate, and were diagnosed with Babesiosis. Diagnostic work up was carried out by taking venipuncture blood sample from the cattle and sent to the Clinical Pathology Laboratory for complete blood count (CBC) and biochemistry. Blood sample was also sent to Parasitology Laboratory for blood protozoa evaluation. Ticks were also collected and sent to Parasitology Laboratory for the identification of parasites. Berenil ® 5% (Diminazene Aceturate) injection was administered intramuscularly and Ivermectin pour on was applied topically against the blood parasites and for both endo and ecto parasites. The most significant features of the disease are the persistent and consistent lymphocytosis and monocytosis that proves suggestive of the disease from the blood picture and the disease is also associated with muscle degenerations and severe pains and these are additional signs to be observed during the diagnosis of Babesiosis. Keyword: Cattle, Babesiosis, Jaundice, 5 % Diminazene Aceturate, Ivermectin

Tristeza parasitária bovina no Sertão da Paraíba

Descrevem-se 24 surtos de tristeza parasitária bovina no sertão paraibano, sendo 18 de anaplasmose por Anaplasma margimale, dois de babesiose por Babesia bigemina, dois por Babesia não identificada e dois por infecção mista de A. marginale e Babesia sp. Os surtos ocorreram entre agosto de 2007 a outubro de 2009, porém, com uma concentração dos surtos no final do período chuvoso e início do período seco de cada ano, sendo 22 em animais adultos e dois em bezerros de aproximadamente 11 meses. Dois surtos ocorreram em bovinos da raça Nelore, um em animais da raça Gir e os 21 restantes ocorreram em animais das raças Holandês, Pardo Suiço e mestiços das mesmas com zebuínos. Conclui-se que no sertão da Paraíba há áreas de instabilidade enzoótica, ocorrendo surtos de tristeza no final da época de chuvas, principalmente nas áreas de planaltos e serras da região da Borborema e em áreas úmidas como a Bacia do Rio do Peixe, Rio Piranhas e Rio Espinharas em que há a formação de microclimas favoráveis à sobrevivência do carrapato.

Surtos de babesiose cerebral em bovinos leiteiros no nordeste brasileiro

This paper reports the epidemiological, clinical, laboratorial and necropsy findings of three cerebral babesiosis outbreaks in dairy cattle from northeast Brazil. These outbreaks affected a total of nine Holstein x Gir crossbred and Girolando cattle. Clinical signs included neurological disturbances, pale mucous membranes with variable degrees of icterus, hemoglobinuria, anorexia, fever, apathy, tachycardia, tachypnea, and reduction in milk yield. Five cases of marked regenerative anemia with Babesia bovis parasitized erythrocytes were identified by hematology analysis. Three necropsy findings revealed pale mucous membranes, splenomegaly, enlarged and yellowish liver, congested and edematous gall bladder containing viscous granular bile, red urine, and dark red kidneys. Gray matter of telencephalic and cerebellar cortices consistently had a typically pink-cherry discoloration. Imprint from the kidney reveals B. bovis in red cells. The disease can have an important economical impact in the northeast region due to productivity loss, mortality rate and costs of treatments.

Aspectos epidemiológicos de um surto de babesiose cerebral em bovinos em zona livre de carrapato

Descrevem-se os aspectos epidemiológicos de um surto de babesiose cerebral ocorrido em bovinos no município de Santa Vitória do Palmar, RS em uma propriedade localizada geograficamente na Latitude S 33°05'23" e Longitude WO 53°09'29", região considerada zona livre de Rhipicephalus (Boophilus) microplus. Em meados de novembro de 2007 foram transferidos para essa propriedade quatro touros, quatro novilhas e duas vacas provenientes do município de Minas do Leão,RS localizado geograficamente na Latitude S 30°12'07" e Longitude WO 52°03'25". De um total de 393 animais, 40 bovinos adultos morreram no período entre 19 de janeiro e 2 de março de 2008. O diagnóstico foi realizado pela observação das lesões macroscópicas e pela presença de numerosas formas parasitárias de Babesia bovis em impressões de fragmentos do córtex telencefálico coradas por Giemsa, que foram enviados ao Laboratório Regional de Diagnóstico da Faculdade de Veterinária da UFPel (LRD). Sugere-se que o clima favorável com temperaturas médias entre 23,2°C e 23,6°C e umidade relativa do ar média entre 77,5° e 75,3% observados no período determinaram a ocorrência de uma geração de carrapatos que ao infestarem e inocularem o agente em animais sem nenhuma imunidade contra o mesmo desencadearam o surto.

Efficiency of a recombinant MSA-2c-based ELISA to establish the persistence of antibodies in cattle vaccinated with Babesia bovis

Bovine babesiosis is caused by Babesia bovis and B. bigemina in Argentina. These protozoans are prevalent north of parallel 30°S, where their natural vector Rhipicephalus ( Boophilus) microplus is widespread. To prevent babesiosis outbreaks in endemic areas, an increasing population of 4–10-month-old calves are vaccinated with low virulence B. bovis R1A (BboR1A) and B. bigemina S1A (BbiS1A) strains. In non-endemic areas, an additional calf population is also vaccinated and boostered as adults, before they are relocated to R. microplus-endemic areas of the country. Serological tests are currently utilized not only to determine the status of natural Babesia spp. infections, but also to confirm the infection caused by vaccine strains. For this purpose, an indirect enzyme immunoassay (ELISA) based on the recombinant major surface antigen-2c (rMSA-2c) of B. bovis expressed in Escherichia coli, was standardized using sera from Babesia spp. experimentally infected cattle. ELISA rMSA-2c was validated using sera obtained weekly during 336 days from steers primed and boostered with BboR1A and/or BbiS1A on days 0 and 154, then compared with the immunofluorescent-antibody test (IFAT). Western blot (WB) protein analysis was used to confirm the specificity of the immune response to rMSA-2c. The sensitivity and specificity for ELISA rMSA-2c were 92 and 96% after the Babesia spp. priming and 88 and 73% after the boostering immunization, respectively. The sensitivity and specificity for IFAT were 99 and 90% after priming and 92 and 98% after boostering, respectively. Unlike IFAT, ELISA rMSA-2c detected a remarkable delayed booster response and a significant drop in specificity between 35 and 84 days after the booster immunization. Simultaneously, 87.5% of cattle boostered with B. bigemina showed cross-reactions in the ELISA rMSA-2c, particularly between 63 and 77 days after the inoculation. A reaction against E. coli was observed, since bands of approximately 40 and/or 42 kDa were detected using sera from cattle before and after Babesia spp. inoculations. ELISA rMSA-2c showed to be useful between 42 and 98 days after priming with Babesia spp. live vaccine to evaluate the success of infecting cattle. However, after boostering the test showed low specificity.

Tristeza parasitária bovina na região sul do Rio Grande do Sul: estudo retrospectivo de 1978-2005

Foi realizado um estudo retrospectivo dos casos de tristeza parasitária bovina (TPB) ocorridos no sul do Rio Grande do Sul, área de influência do Laboratório Regional de Diagnóstico (LRD) da Faculdade de Veterinária da Universidade Federal de Pelotas entre 1978 e 2005. De um total de 4.884 materiais de bovinos provenientes de necropsias realizadas e órgãos ou sangue enviados ao laboratório 231 (4,7%) tiveram o diagnóstico de TPB. Desses 231 surtos foram resgatados os dados de 221 diagnósticos dos quais 91 (41,1%) foram causados por Babesia bovis, 11 (4,9%) por Babesia bigemina, e 65 (29,41%) por Anaplasma marginale. Em outros 33 (14,93%) surtos de babesiose não foi informada a espécie de Babesia e em 21 (9,5%) surtos foi detectada infecção mista por Babesia sp e A. marginale. Os índices gerais médios de morbidade, mortalidade e letalidade, resgatados em 149 dos 221 surtos da doença, foram de 11,17%, 6,81% e 70,04%, respectivamente. Verificou-se que, na região estudada, a maioria dos surtos ocorre durante os meses de verão e outono, e que os animais com um a três anos de idade são os mais afetados. Os sinais clínicos nos surtos caracterizaram-se por apatia, orelhas caídas, debilidade, febre, anorexia e emagrecimento. Os valores de hematócrito eram baixos. Hemoglobinúria foi frequentemente observada nos casos de babesiose. Sinais neurológicos estavam presentes nos casos de babesiose por B. bovis e se caracterizaram por transtornos da locomoção, tremores musculares, agressividade e quedas com movimentos de pedalagem. As lesões macroscópicas principais relatadas nos casos de babesiose foram esplenomegalia, hepatomegalia, fígado amarelo, hemoglobinúria, icterícia, hemorragias cardíacas e bile espessa. Congestão do córtex cerebral foi relatada nos casos de babesiose por B. bovis. Nesta região, com população de bovinos de aproximadamente 2.630.000 cabeças as perdas anuais por morte de bovinos pela enfermidade podem ser estimadas em 6.220 cabeças por ano representando um prejuízo econômico anual aproximado de R$3.732.000,00 evidenciando a necessidade de medidas preventivas que evitem a exposição de animais desprote-gidos aos agentes da TPB.

NEW RUMINANT HOSTS AND WIDER GEOGRAPHIC RANGE IDENTIFIED FOR BABESIA ODOCOILEI (EMERSON AND WRIGHT 1970)

Babesia odocoilei was found to infect two previously unknown host species, desert bighorn sheep (Ovis canadensis nelsoni) and musk oxen (Ovibos moschatus), both of which are members of the family Bovidae. Previously, B. odocoilei has been reported in only Cervidae hosts. New geographic regions where B. odocoilei infections have not been reported previously include Pennsylvania and New York, where fatal babesiosis has occurred in reindeer (Rangifer tarandus tarandus); New Hampshire, where elk (Cervus elaphus canadensis) have been affected; and California, home of the infected desert bighorn sheep. Infection with B. odocoilei in these hosts was confirmed by parasite small subunit ribosomal RNA gene sequence analysis. A serosurvey for B. odocoilei antibody activity in New Hampshire showed prevalence rates of 100% at two elk farms and 12% at another farm. Control of potential vector ticks, Ixodes scapularis, especially when translocating livestock, is imperative to prevent outbreaks of babesiosis in managed herds of potential host species.

Epidemiology of babesiosis and anaplasmosis in South and Central America

Babesiosis ( Babesia bovis and Babesia bigemina) and anaplasmosis ( Anaplasma marginale) affect native cattle from Uruguay and northern Argentina to Guatemala. The distribution of Babesia follows the dissemination of the tick vector. Seroepidemiological studies showed that enzootic instability exist in herds i several areas of the region. However, clinical cases occurred less frequently than expected. The babesial tick infection rate is related to the vector abundance which in turn is regulated by climatie. Bos indicus cattle, because of tick resistance, are less likely to be infected by the vector. This can results in herd instability, but clinically is partly compensated by the resistance of Bos indicus and their crosses to babesiosis. Excessive use of acaricides and rotational grazing appears to be related to outbreaks of babesiosis especially in dairy cattle. Factors involved in the epidemiology and transmission of anaplasmosis are not well defined. The role of ticks, haematophagous diptera, iatrogenic and intrauterine transmissions needs to be investigated under local conditions. Therefore, the knowledge of this disease in meager. Utilization of biotechnological methods may help in obtaining information on Babesia-Boophilus-Bos relationships and on the transmission of A. marginale.

Outbreaks of babesiosis in domestic livestock in the eastern region of the Sudan

Outbreaks of babesiosis in domestic livestock in the eastern region of the Sudan

An Outbreak of Babesiosis (B. divergens) in a Dairy Herd Comprising Different Age Groups of Cattle

Outbreaks of acute bovine babesiosis affecting several individuals within a herd are well known among veterinary practitioners and farmers within different parts of Sweden. Although outbreaks may not occur every year, they are feared by the farmers due to the unpredictability of the disease, its suddeness of onset, its rapid course, and the high mortality unless treated. Sporadic outbreaks of acute bovine babesiosis comprising several animals within a limited time period have been previously reported in Sweden (Linnaeus 1747, Bergman & Waxberg 1915, Heijbel 1928), in Finland (Hinderson 1928), in Norway as cited by Tambs-Lyche (1943), in the United Kingdom (Donnelly et al. 1970) and elsewhere within the area where B. divergens is distributed (Tambs-Lyche 1943, Purnell 1980). In all of these cases groups of animals had been transferred onto pastures where clinical cases of bovine babesiosis were known to occur from areas where the disease was rare or had never occurred; i.e. unexposed animals were transferred onto pastures with Babesia infected ticks. The farmers first became aware of this situation after the outbreak had occurred.