A study on the determination of risk factors associated with babesiosis and prevalence of Babesia sp., by PCR amplification, in small ruminants from Southern Punjab (Pakistan)

Babesiosis is a parasitic infection due to the multiplication of tick borne parasite, Babesia sp., in erythrocytes of host, which includes a wide variety of vertebrates including small ruminants causing decreased livestock output and hence economic losses. The objective of the present study was to establish a PCR based method for the detection of Babesia sp. in small ruminant population in Southern Punjab and to determine the risk factors involve in the spread of babesiosis. A total of 107 blood samples were collected from 40 sheep and 67 goats in seven districts of Southern Punjab from randomly selected herds. Data on the characteristics of the animals and the herd were collected through questionnaires. 36 blood samples (34% of total) produced the DNA fragment specific for 18S rRNA gene of Babesia sp., by PCR amplification, of which 20 were sheep and 16 were goats. Samples from all seven district contained Babesia positive samples and prevalence varied between 18 to 68%. It was observed that male animals (P = 0.009) and young animals under one year of age (P = 0.01) were more prone to the parasite. It was observed that herds consist of more than 15 animals (P = 0.007), composed of mixed species of small ruminants (P = 0.022), associated with dogs (P = 0.003) and dogs having ticks on their bodies (P = 0.011) were among the major risk factors for the spread of babesiosis in small ruminants.     

Description of Babesia duncani n.sp. (Apicomplexa: Babesiidae) from humans and its differentiation from other piroplasms

The morphologic, ultrastructural and genotypic characteristics of Babesia duncani n.sp. are described based on the characterization of two isolates (WA1, CA5) obtained from infected human patients in Washington and California. The intraerythrocytic stages of the parasite are morphologically indistinguishable from Babesia microti, which is the most commonly identified cause of human babesiosis in the USA. Intraerythrocytic trophozoites of B. duncani n.sp. are round to oval, with some piriform, ring and ameboid forms. Division occurs by intraerythrocytic schizogony, which results in the formation of merozoites in tetrads (syn. Maltese cross or quadruplet forms). The ultrastructural features of trophozoites and merozoites are similar to those described for B. microti and Theileria spp. However, intralymphocytic schizont stages characteristic of Theileria spp. have not been observed in infected humans. In phylogenetic analyses based on sequence data for the complete18S ribosomal RNA gene, B. duncani n.sp. lies in a distinct clade that includes isolates from humans, dogs and wildlife in the western United States but separate from Babesia sensu stricto, Theileria spp. and B. microti. ITS2 sequence analysis of the B. duncani n.sp. isolates (WA1, CA5) show that they are phylogenetically indistinguishable from each other and from two other human B. duncani-type parasites (CA6, WA2 clone1) but distinct from other Babesia and Theileria species sequenced. This analysis provides robust molecular support that the B. duncani n.sp. isolates are monophyletic and the same species. The morphologic characteristics together with the phylogenetic analysis of two genetic loci support the assertion that B. duncani n.sp. is a distinct species from other known Babesia spp. for which morphologic and sequence information are available.     

An assessment of the puku (Kobus vardonii Livingstone 1857) population at Lake Rukwa,Tanzania

The population of puku, Kobus vardonii, at Lake Rukwa, one of only two in Tanzania, is poorly known. A multi‐species dry season game count carried out in Rukwa Game Reserve (RGR) in 2004 estimated a population size of 1729, but was associated with a high margin of error [coefficient of variation (CV) 0.88]. To increase the precision for the local puku population estimate, we conducted a zig‐zag line transect survey restricted only to areas occupied by puku in the dry season of 2006. This survey technique produced an estimate of 776 individuals and the CV was considerably reduced to 0.29. Puku herd size was comparable with the studies carried out in the Kilombero valley, Tanzania and in Kasanka National Park, Zambia, thus broadly confirming the herding ecology of this species. We found that pukus were restricted to the central parts of the floodplains, suggesting an avoidance of habitats used by pastoralists at the edge of RGR. Compared with the estimates of the puku population made in the 1980s, the puku population has declined. We recommend regular monitoring and enforcement of the current management plan to conserve the local puku population.     

Bovine babesiosis: Cattle protected in the field with a frozen vaccine containing Babesia bovis and Babesia bigemina cultured in vitro with a serum-free medium

An attenuated live vaccine containing Babesia bovis and B. bigemina cultured in vitro with a serum-free medium was assessed for its clinical protection conferred of naïve cattle, under natural tick-challenge in a high endemicity zone to Babesia spp. Three groups of six animals were treated as follows: group I (GI) received a vaccine derived from parasites cultured with a free-serum medium; group II (GII) were immunized with the standard vaccine, with parasites cultured in a medium supplemented with 40% (v/v) bovine serum; and a control group (GIII) inoculated with non-infected bovine erythrocytes. Inocula were administered by IM route. Experimental animals were kept during 23 days after vaccination in a cattle farm free of ticks and Babesia spp. Thereafter, cattle were moved to a high endemicity farm for natural exposure to Babesia spp. transmitted by Rhipicephalus microplus ticks. Protection against clinical babesiosis was observed in bovines belonging to GI (100%) and GII (83.33%), while the control animals (GIII) were not protected, and showed severe clinical signs, closely related to babesiosis, were observed for at least three consecutive days during the challenge. These were fever, anemia, which were measured simultaneously, and circulating parasites were detected by optic light microscopy. All cattle showed B. bovis and B. bigemina in stained blood films during the challenge; B. bovis antibody titers were higher than those to B. bigemina in GI and GII, and lower titers were determined in GIII. The protective capacity of the vaccine derived from B. bovis and B. bigemina cultured in vitro in a serum-free medium was demonstrated.     

A note on the distribution and abundance of puku, Kobus vardoni Livingstone, in Kasanka National Park, Zambia

This study (1994) examines the distribution and abundance of puku ( Kobus vardoni Livingstone) in Kasanka National Park (area=470 km²) Zambia, following five years of anti‐poaching control. The puku is an important 'flagship' species for the park. Most puku were confined to a limited number ( n =19) of river floodplains and dambos (total area=20·29 km²) towards the centre of the park. Large areas of 'suitable' habitat contained few, if any animals. The total population was estimated to be 613 (confidence limits=414–967) with an average density of 35·93 km⁻² on occupied sites. The population sex ratio was markedly biased towards females (mean=3·4 females to 1 male), but group sizes were similar to those recorded in other African studies. Male groups were on average (2·6), smaller than those of females (7·3). Males appeared to be particularly vulnerable to poaching. The distribution of puku reflected a patchy distribution of resources and a flexible social system. Puku numbers have increased two fold since the previous (1989) survey. Other species have faired less well. Further work is required to clarify dispersal mechanisms. Taylor's power law may provide a useful model for describing population dispersion. Kasanka is an important local refuge for this increasingly threatened species in Zambia. Metapopulation theory may be applicable to puku because of their ability to move between patches, during seasonal flooding.     

Identification, genetic diversity and prevalence of Theileria and Babesia species in a sheep population from Northern Spain

The genetic diversity and prevalence of virtually all Theileria and Babesia species in a sheep population were studied using a specifically designed reverse line blot macroarray. The amplified hypervariable V4 region of the 18S rRNA gene was hybridised against generic and species-specific probes. In a first screening (Study I), 320 apparently healthy animals corresponding to 32 flocks located in the Basque Country (Northern Spain) were analysed. The survey demonstrated a high prevalence of subclinical infections (64.7%). Three Theileria genotypes were identified, sharing 96.7-97.0% similarity between their 18S rRNA gene sequences: Theileria ovis, Theileria sp. OT1 (99.6% similarity with the recently described pathogenic piroplasm Theileria sp. China 1), and Theileria sp. OT3. Two Babesia species sharing 91.5% similarity were also detected: Babesia ovis and Babesia motasi. The complete 18S rRNA gene sequences of these and other piroplasm species were phylogenetically analysed. Prevalence of piroplasms was also investigated in a second group of 80 sheep from 16 flocks reared in mountain areas that had been heavily exposed to ticks and had suffered a recent abortion episode (Study II). The screening revealed a significantly higher (P < 0.05) prevalence (78.7%) of piroplasm infections compared to Study I. Although the prevalence rates for some piroplasm species were significantly related to abortion (e.g. Theileria sp. OT3), decreases in the red cell parameters were not significant. The widespread distribution of Theileria spp. in the studied sheep population suggests that the parasites involved are of relatively low pathogenicity, in contrast to what has been reported for Theileria sp. China 1 in other countries.     

Tick-borne diseases in ruminants of Central and Southern Italy: epidemiology and case reports

Sera and blood from cattle and sheep were examined for the presence of Babesia and Theileria spp by microscopy and serology at the Parasitology Department of the Istituto Zooprofilattico Sperimentale of Abruzzo and Molise (IZSAM). Of the 47 bovine herds (323 animals) tested, 15 were found positive for Babesia bigemina and 1 for Babesia bovis. Two outbreaks occurred, one caused by B. bigemina and one by B. bovis. The B. bigemina outbreak occurred in Abruzzo and has been followed for two years. The isolate of B. bigemina was very pathogenic leading to the death of two cows out of 57. The vector responsible of the transmission appeared to be Rhipicephalus bursa. Parasites were observed in the erythrocytes for 30 days whereas sera were positive to indirect immunofluorescence (IFA) for at least one year. The B. bovis outbreak occurred in the province of Mantova (Northern Italy) in a group of 70 beef cattle imported from France. The infection resulted in the death of 5 animals and severe illness in another 6. In contrast with what occurred for Babesia infection, no clinical cases were recorded in cattle when species of Theileria were detected by microscopy. Of the 24 bovine herds (252 animals) tested for Theileria, 21 were found positive for the T. "sergenti"/buffeli/orientalis group. Single and mixed infection of T. "sergenti" and T. buffeli/orientalis were detected in herds of cross-bred cattle from Abruzzo and Marche. The parasites were identified by using a polymerase chain reaction which amplified DNA encoding p32/34. Most of the collected ticks (90%) were adults of R. bursa whereas the others were adults of Hyalomma detritum. During the period the animals have been observed (18 months), no clinical cases have been recorded and no associations have been found between blood abnormalities and animals found infected with Theileria. Prevalences of subclinically infected carriers increased from February till December (95.4%) even if the animals were indoors and no ticks were present. The prevalence then dropped dramatically six months later (76.7%). In calves less than 1 year old, the prevalence of infection significantly (p<0.05) increased with age, however intraerythrocytic stages of Theileria were found in the blood of three newborn calves (<7 days of age). Of the 18 ovine flocks tested for Babesia spp. (150 animals examined), 1 was positive for B. ovis and 2 for B. motasi. B. motasi infection was not associated with symptoms, while an outbreak of babesiosis caused by B. ovis occurred in Abruzzo. The infection resulted in the death of 3 animals (0.75% of the flock), two rams (20% of the total number) and a ewe, and severe illness in another 5 ewes (2% of the flock). Specimens of R. bursa and R. turanicus were collected from the infected animals. Of the 18 flocks (150 animals) examined, 12 were microscopically positive for Theileria spp. No clinical cases were recorded and identification at species level was not possible on the basis of morphological criteria. The prevalence distribution of infected herds and infected animals within herds and flocks have been calculated by a Monte Carlo simulation model, running 10,000 iterations. The most likely levels of prevalence of infected herds and infected animals within herds found for the species observed were as follows: 20% for B. bigemina with a prevalence within herd of 27%, 11% for B. bovis (18% within herd), 10% for Babesia ovis (19% within herd), 10% for B. motasi (17.5% within herd), 63% for Theileria in cattle (66% within herd) and 51% for Theileria in sheep (55% within herd).     

Prevalence of ixodid ticks on cattle in Mazandaran province, Iran

A survey was carried out to investigate the prevalence of hard tick species (Acari: Ixodidae) on cattle in Mazandaran province, Iran. A total of 953 ticks were collected from 86 infested cattle during activating seasons of ticks during 2004-2005. Nine species were identified: Boophilus annulatus (51.3%), Rhipicephalus bursa (16.8%), Haemaphysalis punctata (6.3%), Ixodes ricinus (6.8%), Hyalomma marginatum (12.5%), Hyalomma anatolicum excavatum (5.2%), Hyalomma asiaticum (0.6%), Hyalomma detritum (0.2 %), and Dermacentor spp. (0.1%). The results show that Boophilus annulatus, Rhipicephalus bursa, and Hyalomma species are dominant tick species in the surveyed area.     

General review of tick species present in Portugal

At present, 24 species are known to occur in Portugal: Argas vespertilionis, Ornithodoros maritimus and Ornithodoros erraticus in Argasidae; Ixodes acuminatus, Ixodes bivari, Ixodes canisuga, Ixodes frontalis, Ixodes hexagonus, Ixodes ricinus, Ixodes simplex simplex, Ixodes ventalloi, Ixodes vespertilionis, Dermacentor marginatus, Dermacentor pictus', Haemaphysalis hispanica, Haemaphysalis inermis, Haemaphysalis punctata, Rhipicephalus bursa, Rhipicephalus pusillus, Rhipicephalus sanguineus, Rhipicephalus turanicus, Hyalomma lusitanicum, Hyalomma marginatum marginatum and Boophilus annulatus in Ixodidae. The more relevant diseases transmitted to cattle by ticks, particulary in Ribatejo and Alentejo regions, are the babesiosis due to Babesia bigemina and Babesia bovis, the theileriosis by Theileria annulata and the anaplasmosis due to Anaplasma marginale; the theileriosis by Theileria mutans2 may not be considered significant. The sheep and goats parasitoses transmitted by ticks are of less importance than the cattle diseases. However the babesiosis due to Babesia motasi and Babesia ovis and also theileriosis by Theileria hirci3 are present in some districts of the country.     

Animal babesiosis: an emerging zoonosis also in Italy?

In Italy, babesiosis is widespread in several Central and Southern Regions, but few data are available on its presence in most Italian areas. In 2004 a project was financed by the MIUR to investigate on the babesiosis epidemiology in vertebrate and invertebrate hosts, and on the transmission risk for humans in Central and Northern Regions of the country. Microscopy and/or molecular tools were applied to blood samples of wild animals, livestock and pets, and to 1,677 ticks collected on animals or in the environment, with the aim of detect babesial parasites. Moreover, serological tests were used to evaluate the circulation of these protozoa among animals and people at risk. Microscopy identified as positive 5.0% of the animals, mostly living in Central Regions, but also in Northern areas considered Babesia-free. Serology evidenced the same general trend. PCR detected "piroplasm" DNA in 13.8% of the animals, and sequencing identified babesial parasites in 101/233 samples. The ticks were identified as belonging to 12 species, mostly represented by Ixodes ricinus, Rhipicephalus sanguineus and Dermacentor marginatus. Molecular analyses evidenced babesial parasites in 3.8% of them; in Rh. sanguineus was also demonstrated the vertical transmission of Babesia canis canis. To date 30 human sera have been analysed: 3 showed antibodies to B. microti. Animal babesiosis is largely present among pets, wild and farm animals, whereas goats seem refractory to the infection. In wild ungulates have been found the B. divergens-like, and the Babesia EU1 strains (reported in Italy in humans). Our findings evidenced the low reliability of microscopy in epidemiological studies, and the need of new/improved immunological tests to face diagnostic problems. The monitoring of infected areas and infection rates, joined to appropriate control programs, seems necessary to avoid the transmission of babesiosis to humans.     

PCR-based detection of Babesia bovis and Babesia bigemina in their natural host Boophilus microplus and cattle

PCR and nested-PCR methods were used to assess the frequency of Babesia bovis and Babesia bigemina infection in Boophilus microplus engorged females and eggs and in cattle reared in an area with endemic babesiosis. Blood and the engorged female ticks were from 27 naturally infested calves and 25 crossbred cows. The frequency of both Babesia species was similar in calves and cows (P>0.05). Babesia bovis was detected in 23 (85.2%) calves and in 25 (100%) cows and B. bigemina was detected in 25 (92.6%) calves and in 21 (84%) cows. Mixed infections with the both Babesia species were identified in 42 animals, 21 in each age category. Of female ticks engorged on calves, 34.9% were negative and single species infection with B. bigemina (56.2%) was significantly more frequent (P<0.01) than with B. bovis (4.7%). Most of the females (60.8%) engorged on cows did not show Babesia spp. infection and the frequency of single B. bovis infection (17.6%) was similar (P>0.05) to the frequency of single B. bigemina infection (15.9%). Mixed Babesia infection was lower (P<0.01) than single species infection in female ticks engorged either in cows (5.7%) or in calves (4.3%). An egg sample from each female was analysed for the presence of Babesia species. Of the egg samples from female ticks infected with B. bovis, 26 (47.3%) were infected while from those from female ticks infected with B. bigemina 141 (76.6%) were infected (P<0.01). The results showed that although the frequency of both species of Babesia was similar in calves and cows, the infectivity of B. bigemina was higher to ticks fed on calves while to those ticks fed on cows the infectivity of both Babesia species was similar.     

Identification of novel Babesia and Theileria genotypes in the endangered marsupials, the woylie (Bettongia penicillata ogilbyi) and boodie (Bettongia lesueur)

Piroplasms, which include the genera Theileria and Babesia, are blood-borne parasites transmitted mainly by tick vectors. Relatively little is known about their prevalence and clinical impact in Australian marsupials. In the present study the occurrence and molecular phylogeny of these parasites were studied in both wild and captive marsupials from Western Australia (WA) and Queensland (QLD). Blood samples were screened by microscopy and molecular methods, using PCR and DNA sequencing of the 18S ribosomal RNA gene (18S rDNA). Overall, 7.1% of the blood samples (8/113) were positive for piroplasm 18S rDNA. Theileria and Babesia rDNA was detected in 0.9% (1/113) and 6.2% (7/113) of the animals, respectively. The single Theileria positive was identified in one of three boodies (Bettongia lesueur) screened from a wildlife rehabilitation centre in WA, while all seven Babesia positives were detected in WA in wild captured woylies (Bettongia penicillata ogilbyi). Small intraerythrocytic inclusions were observed in blood films made from six of these individuals. This is the first report of a Babesia sp. in woylies, and Theileria sp. in boodies. Phylogenetic analysis indicated that the woylie-derived Babesia was genetically distinct and most closely related to Babesia occultans, the causative agent of a benign form of cattle babesiosis (genetic similarity 98.4%). The Theileria identified was most closely related to the marsupial-derived species Theileria penicillata from the woylie, Theileria brachyuri from the quokka (Setonix brachyurus), and Theileria sp. from the long-nosed potoroo (Potorous tridactylus).     

Human babesiosis: an emerging tick-borne disease

Human babesiosis is an important emerging tick-borne disease. Babesia divergens, a parasite of cattle, has been implicated as the most common agent of human babesiosis in Europe, causing severe disease in splenectomized individuals. In the US, Babesia microti, a babesial parasite of small mammals, has been the cause of over 300 cases of human babesiosis since 1969, resulting in mild to severe disease, even in non-splenectomised patients. Changing ecology has contributed greatly to the increase and expansion of human babesiosis in the US. A relatively recently described babesial parasite, the WA1-type, has been shown to be the causative agent in seven human cases in the western US. This parasite is closely related to babesial parasites isolated from large wild ungulates in California. Like B. microti, WA1-type parasites cause mild to severe disease and the immunopathogenesis of these parasites is distinctly different from each other in experimental infections of hamsters and mice. A B. divergens-like parasite was also identified as the cause of a fatal human babesiosis case in Missouri. Isolated cases of human babesisosis have been described in Africa and Mexico, but the causative parasites were not well characterized. Standard diagnostic techniques for human infection, such as examination of Giemsa-stained thin blood smears and serology, have been complemented with molecular techniques, such as PCR. Current treatment for babesiosis is focused on a regimen of clindamycin and quinine, although new drugs have shown promise. Prevention of infection relies on self-monitoring for the presence of ticks and, in some locations, targeted application of pesticides to decrease tick abundance. Identification of human infection with Babesia spp. will probably increase as physicians and the public become more aware of the disease, as people live and recreate in rural tick-infested areas, and as the numbers of immunocompromised individuals increase.     

Babesia bigemina sexual stages are induced in vitro and are specifically recognized by antibodies in the midgut of infected Boophilus microplus ticks

Babesia bigemina, a causative agent of bovine babesiosis, is transmitted from one bovine to another only by infected ticks. The life cycle of B. bigemina includes a sexual phase in the tick host; however, molecules from sexual stages of any Babesia species have not been characterized. This is the first report of the induction of sexual stages of any Babesia species in vitro, free of tick antigens. Intraerythrocytic parasites were cultured in vitro for 20h using an induction medium. Extraerythrocytic parasites were first seen 3h post induction; elongated stages with long projections appeared at 6h post induction and by 9h they paired and fused to form larger stages. Round zygotes appeared 20h post induction. Moreover, by using Percoll gradients, sexual stages were purified free of contaminating intraerythrocytic stages. Purified parasites were used to generate polyclonal antibodies, which specifically bound to antigens expressed in sexual stages induced in vitro, but not to antigens expressed in intraerythrocytic stages. Importantly, these antibodies specifically identified sexual stages from midguts of female Boophilus microplus ticks fed on infected cattle.     

Cryptosporidium spp., Giardia intestinalis,and Enterocytozoon bieneusi in Captive Non-Human Primates in Qinling Mountains

Non-human primates (NHPs) are confirmed as reservoirs of Cryptosporidium spp., Giardia intestinalis, and Enterocytozoon bieneusi. In this study, 197 fresh fecal samples from 8 NHP species in Qinling Mountains, northwestern China, were collected and examined using multilocus sequence typing (MLST) method. The results showed that 35 (17.8%) samples were positive for tested parasites, including Cryptosporidium spp. (3.0%), G. intestinalis (2.0%), and E. bieneusi (12.7%). Cryptosporidium spp. were detected in 6 fecal samples of Macaca mulatta, and were identified as C. parvum (n=1) and C. andersoni (n=5). Subtyping analysis showed Cryptosporidium spp. belonged to the C. andersoni MLST subtype (A4, A4, A4, and A1) and C. parvum 60 kDa glycoprotein (gp60) subtype IId A15G2R1. G. intestinalis assemblage E was detected in 3 M. mulatta and 1 Saimiri sciureus. Intra-variations were observed at the triose phosphate isomerase (tpi), beta giardin (bg), and glutamate dehydrogenase (gdh) loci, with 3, 1, and 2 new subtypes found in respective locus. E. bieneusi was found in Cercopithecus neglectus (25.0%), Papio hamadrayas (16.7%), M. mulatta (16.3%), S. sciureus (10%), and Rhinopithecus roxellana (9.5%), with 5 ribosomal internal transcribed spacer (ITS) genotypes: 2 known genotypes (D and BEB6) and 3 novel genotypes (MH, XH, and BSH). These findings indicated the presence of zoonotic potential of Cryptosporidium spp. and E. bieneusi in NHPs in Qinling Mountains. This is the first report of C. andersoni in NHPs. The present study provided basic information for control of cryptosporidiosis, giardiasis, and microsporidiosis in human and animals in this area.     

Babesia gibsoni: Identification, expression, localization, and serological characterization of a Babesia gibsoni 22-kDa protein

Babesia gibsoni causes canine babesiosis. Here, we describe the identification and characterization of a novel gene, BgP22, containing an open reading frame of 621 bp and encoding a 22-kDa protein from B. gibsoni, as a serodiagnostic candidate. The recombinant BgP22 (rBgP22) was expressed and used as an antigen to produce anti-rBgP22 sera in mice. Using these anti-rBgP22 sera, a native 22-kDa protein was recognized by Western blot analysis and observed in the membrane of the parasites by immunofluorescent antibody tests (IFAT). The enzyme-linked immunosorbent assay (ELISA) using the rBgP22 detected specific antibodies to this protein in the sera of dogs experimentally and naturally infected with B. gibsoni in chronic stage. Furthermore, it did not show a cross reaction with the closely related apicomplexan parasites, indicating that the rBgP22 could be used as a diagnostic antigen for a detection of the chronic carrier stages of B. gibsoni infection.     

Identification of newly isolated Babesia parasites from cattle in Korea by using the Bo-RBC-SCID mice

Attempts were made to isolate and identify Korean bovine Babesia parasite. Blood samples were collected from Holstein cows in Korea, and Babesia parasites were propagated in SCID mice with circulating bovine red blood cells for isolation. The isolate was then antigenically and genotypically compared with several Japanese isolates. The Korean parasite was found to be nearly identical to the Oshima strain isolated from Japanese cattle, which was recently designated as Babesia ovata oshimensis n. var. Haemaphysalis longicornis was the most probable tick species that transmitted the parasite.     

Fatal experimental transplacental Babesia gibsoni infections in dogs

A Babesia gibsoni infected bitch was mated with an uninfected dog in order to determine whether this parasite could be vertically transmitted. The bitch delivered a litter of four live and one stillborn pup. The four pups died from congenital babesiosis between 14 and 39 days post-birth. Babesia gibsoni DNA was detected in tissue from all five pups. These results show that vertical transmission occurred by the uterine route and not via the transmammary route. This is the first confirmed report of transplacental Babesia infection in any animal species.     

Vaccination against canine babesiosis

It has been known for several decades that the soluble parasite antigen (SPA) of several Babesia species can be used as a vaccine against the clinical manifestations of babesiosis. Originally observed in the plasma of infected animals, SPA can also be recovered from the supernatants of in vitro cultures of these parasites. Variable success has been reported for vaccines against the bovine and canine Babesia parasites, which seems to be related to antigenic diversity within Babesia species. In this article, an overview is presented of the development of such vaccines for dogs, and additional research that has led to improvement of an SPA-based vaccine against Babesia canis in dogs.