Vertical Transmission of Babesia microti in BALB/c Mice: Preliminary Report

Babesia spp. (Apicomplexa, Piroplasmida) are obligate parasites of many species of mammals, causing a malaria-like infection- babesiosis. Three routes of Babesia infection have been recognized to date. The main route is by a tick bite, the second is via blood transfusion. The third, vertical route of infection is poorly recognized and understood. Our study focused on vertical transmission of B. microti in a well-established mouse model. We assessed the success of this route of infection in BALB/c mice with acute and chronic infections of B. microti. In experimental groups, females were mated on the 1st day of Babesia infection (Group G0); on the 28th day post infection (dpi) in the post- acute phase of the parasite infection (G28); and on the 90th and 150th dpi (G90 and G150 group, respectively), in the chronic phase of the parasite infection. Pups were obtained from 58% of females mated in the post-acute phase (G28) and from 33% of females in groups G90 and G150. Mice mated in the pre-acute phase of infection (G0) did not deliver pups. Congenital B. microti infections were detected by PCR amplification of Babesia 18S rDNA in almost all pups (96%) from the experimental groups G28, G90 and G150. Parasitaemia in the F1 generation was low and varied between 0.01-0.001%. Vertical transmission of B. microti was demonstrated for the first time in BALB/c mice.

Risk assessment of transfusion-associated babesiosis in Tyrol: appraisal by seroepidemiology and polymerase chain reaction

BACKGROUND

After malaria, babesiosis is the second most common transfusion-transmitted parasitic disease in the United States. In Europe, one reported transfusion case, concerning Babesia microti, occurred in Germany.

STUDY DESIGN AND METHODS

Due to the fact that Babesia spp. are present in Tyrolean ticks, the aim of this study is to assess the occurrence of immunoglobulin (Ig)G antibodies against the Babesia divergens complex, including B. divergens and Babesia venatorum (EU1), as well as B. microti by screening a representative collective of 988 blood donors from North and East Tyrol (Austria) with indirect immunofluorescence antibody test. Additionally, we investigated 206 local ixodid ticks for the presence of babesial DNA by polymerase chain reaction.

RESULTS

Seroprevalence data resulted in rates of 2.1% for IgG antibodies against the B. divergens complex and 0.6% against B. microti in Tyrolean blood donors. All sera could be confirmed by independent retesting. Our data indicate that cross-reactivity is high between B. divergens and B. venatorum and lower than 19.8% between B. divergens and B. microti.

CONCLUSIONS

This study shows that Babesia spp. are present in the Tyrols, which blood donors come into serologic contact with, and that we have to consider how to sustain blood product safety concerning this new challenge. Additionally, it is the first description of B. venatorum in the Tyrols, found in one Ixodes ricinus at the Italian border.

The risk of vector-borne infections in sled dogs associated with existing and new endemic areas in Poland: Part 1: A population study on sled dogs during the racing season

The achievements of sled dogs in competitions depend both on their training and on their health. Vector-borne infections may lead to anaemia, affect joints or heart muscle or even cause death. Between December 2009 and October 2010, one hundred and twenty six individual blood samples were collected from 26 sled dog kennels situated in different regions of Poland. The majority of samples were taken during the racing season (winter 2009/10). The prevalences of 3 vector-borne infections- including 2 'old pathogens' Anaplasma phagocytophilum and Babesia canis, and 'new pathogen' Hepatozoon canis-were estimated in sled dogs using PCR and nested PCR. Additionally, 25 serum samples originating from a subset of 3 kennels situated in a tick-borne encephalitis (TBE) endemic area (Mazowiecki region), were tested for antibodies against the tick-borne encephalitis virus (TBEV). Because of the recently reported occurrence of Dirofilaria repens in Central Poland and that of fatal cases of unknown aetiology in two of the kennels, blood samples collected from dogs at these kennels in 2010 and in February-May 2013 and from two unaffected kennels were checked for evidence of presence of this parasite. Babesia canis DNA was detected in 11 sled dogs (4 with clinical babesiosis, 7 asymptomatic; 8.7%) inhabiting mainly endemic regions of Poland (9/11 cases). Three serum samples originating from one location tested positive for TBEV antibodies (total seroprevalence: 3/25=12%, local seroprevalence: 3/12=25%). The risk of TBEV infection was associated with previous B. canis infections. Dirofilaria repens DNA was detected in 15 dogs (44%). Prevalence was especially high in two sled dog kennels situated near Grodzisk Mazowiecki (50-57%). No blood samples tested positive for A. phagocytophilum or H. canis DNA. The present study has established that the prevalence of vector-borne pathogens in working sled dogs is significant in the endemic regions and has justified the important role of surveillance of reservoir hosts in the epidemiology of TBE. Our results emphasize the need for regular monitoring for the presence of D. repens.

Babesia canis and tick-borne encephalitis virus (TBEV) co-infection in a sled dog

INTRODUCTION AND OBJECTIVES

Sporting dogs, including sled dogs, are particularly prone to tick-borne infection either due to training/racing in forest areas or through visits to endemic areas. The aim was to present tick-borne infections in a 6-dog racing team after a race in Estonia.

MATERIALS AND METHODS

On the 4th day after return to Poland, the first dog presented with babesiosis symptoms and was diagnosed and treated accordingly. Next morning, the dog showed neurological symptoms and was diagnosed with tick-borne encephalitis (TBE). Diagnosis was confirmed by a high level of IgG antibodies (922 IU/ml), detected in serum 3 months later. The second dog presented with babesiosis symptoms on the 7th day after return. Babesia DNA was extracted from blood, amplified and sequenced to answer the question of whether the dogs became infected during the race in Estonia or in Poland.

RESULTS AND CONCLUSIONS

Sequencing of a fragment of Babesia 18S rDNA revealed that these two isolates were identical to one another and closely related to the B. canis sequence originally isolated from the dog and Dermacentor reticulatus ticks in Poland. Thus, this is the first confirmed case of B.canis and TBEV co-infection and first confirmed case of TBE in a dog in Poland.

Fluorescent in situ hybridization as a tool to retrospectively identify Cryptosporidium parvum and Giardia lamblia in samples from terrestrial mammalian wildlife

Fecal samples of five terrestrial mammalian wildlife species stored at 4 degrees C or at -20 degrees C for up to 36 months have been tested for human zoonotic enteric parasites (i.e., Cryptosporidium parvum and Giardia lamblia) using combined fluorescent in situ hybridization (FISH) and direct fluorescent antibody techniques. The prevalence of C. parvum and G. lamblia varied from 20 to 63% (mean, 45.8%) and from 13 to 100% (mean, 53.2%), respectively. The prevalence of C. parvum and G. lamblia infections was higher in small rodents (mean, 68.5%) than in other wildlife (mean, 21%). Overall, 31.1% of animals were coinfected, and coinfections were more prevalent in small rodents (mean, 52%) than in other wildlife species (mean, 13.2%). The present study has shown that the FISH assay can be retrospectively applied to fecal samples for the identification of C. parvum oocysts, but is less suitable for the identification of G. lamblia cysts in such samples. Terrestrial mammalian wildlife, particularly small rodents, can contribute to watershed contamination with C. parvum oocysts and G. lamblia cysts. To control contamination, the management of pristine watersheds used for drinking water purposes should incorporate control measures for terrestrial wildlife, especially field rodents residing within such watersheds.

Preliminary molecular characterization of Cryptosporidium parvum isolates of wildlife rodents from Poland

Isolates of Cryptosporidium were collected from 3 species of woodland and field rodents (Clethrionomys glareolus, Microtus arvalis, and Apodemus flavicollis) and were characterized by polymerase chain reaction amplification and sequencing of fragments of the oocyst wall protein (COWP) gene and of the 18S ribosomal RNA gene. Sequence analysis of these markers revealed that the animals were infected with C. parvum, and that the genotype involved was almost identical to the mouse genotype previously described from Mus musculus. Thus, small rodents should be considered as an important reservoir of C. parvum genotypes closely related to the zoonotic genotype 2 and potentially hazardous to humans.

Biological characterisation of Cryptosporidium parvum isolates of wildlife rodents in Poland

The study was undertaken to characterise the C. parvum isolates originating from naturally infected woodland and field rodents: Clethrionomys glareolus (CG), Apodemus flavicollis (AF) and Microtus arvalis (MA). We found that the measurements of oocyst dimensions and oocyst morphology did not allow distinction between the parasite isolates from the 3 rodent species. The mean dimensions were: for CG 4.67 x 4.21, for AF 4.65 x 4.14 and for MA 4.66 x 4.16. These 3 groups of isolates have produced significantly different pictures of infection in C57BL/6 mice. The overall mean oocysts output was: in CG-mice 41,739, in AF-mice 18,000, in MA-mice 10,384 oocysts/1 g of faeces. From these data we suggest that rodent isolates of C. parvum could represent new subgroups in so-called "mouse" C. parvum strain. The successful cross-transmission from wild hosts to laboratory rodents and the close similarity of COWP sequence between our isolates and "mouse" genotype and between "mouse" and zoonotic genotype of C. parvum (genotype C) inform us that all these isolates should be treated as potentially hazardous for human health.

Prevalence and abundance of Cryptosporidium parvum and giardia spp. in wild rural rodents from the Mazury Lake District region of Poland

Prevalence and abundance of Cryptosporodium parvum and Giardia spp. were studied in 3 species of rodents from forests and abandoned agricultural fields in N.E. Poland (Clethrionomys glareolus n = 459; Microtus arvalis n = 274; Apodemus flavicollis n = 209). Overall prevalence was consistently higher in the voles compared with A. flavicollis (70.6, 73.0 and 27.8% respectively for C. parvum and 93.9, 96.3 and 48.3% respectively for Giardia spp.). Prevalence and abundance of infection also varied markedly across 3 years with 1998 being a year of higher prevalence and abundance with both species. Fewer older animals (especially C. glareolus and M. arvalis) carried infection with C. parvum and infections in these animals were relatively milder. Although seasonal differences were significant, no consistent pattern of changes was apparent. Host sex did not influence prevalence or abundance of infection with C. parvum, but made a small contribution to a 4-way interaction (in 5-way ANOVA) with other factors in the case of Giardia spp. The 2 species co-occurred significantly and in animals carrying both parasites there was a highly significant positive correlation between abundance of infection with each, even with between-year, seasonal, host age, sex and species differences taken into account. Quantitative associations were confined to the 2 vole species in the study. These results are discussed in relation to the importance of wild rodents as reservoir hosts and sources of infection for local human communities.

[The ecology of Cryptosporidium parvum infection in small rodent populations]

The prevalence and abundance of Cryptosporidium parvum were studied over a three year period (1997-1999) in three species of rodents sampled from forest and abandoned fields in the Mazury Lake District, Poland. The overall prevalence was consistently higher in voles compared with Apodemus flavicollis (70.6% in Clethrionomys glareolus, 73.0% in Microtus arvalis and 27.8% in A. flavicollis). The prevalence and abundance of infection also varied across the 3 years of the study with 1998 being the year of higher prevalence and abundance of the parasite. Fewer older animals carried the infection, and their infections were relatively mild. We found no consistent pattern of seasonal changes despite the significance of seasonal differences. Host sex did not influence either the prevalence or abundance of infection with C. parvum. A great proportion of recaptured voles developed chronic infections between consecutive trapping sessions and only a small number of animals recovered. However, yellow-necked mice seem to be much more resistant to infection that became self-limiting. Our results firmly establish that the common woodland and grassland wild rodents in the Mazury Lake District constitute a significant and hazardous reservoir of C. parvum for animals and humans.

Calves as a potential reservoir of Cryptosporidium parvum and Giardia sp

Studies on cryptosporidiosis and giardiosis were carried out between March and April 1997 on 75 calves from 9 selected farms of Wielkopolska macroregion. Faecal specimens from calves, 3-13 days old, were screened for oocysts of C. parvum using Ziehl-Neelsen staining and both for oocysts of C. parvum and cysts of Giardia sp. using direct immunofluorescent (MerIFluor Cryptosporidium/Giardia) assay. The oocysts of C. parvum assessed by Ziehl-Neelsen staining were revealed on 6 (67%) of 9 farms examined. The prevalence of infection ranged from 20-88%, and in some farms intensity of oocyst shedding was very high. However, in 35 calves assessed for mixed infections of C. parvum and Giardia sp., oocysts of Cryptosporidium were found in 18 (51%) calves and cysts of Giardia sp. were detected in 5 (14%) of 35 calves. Only in one calf was found coinfection with both parasites. The intensity of Giardia sp. infection was extremely low. Histological examination of the gut sections from immunosuppressed BALB/c mice experimentally infected with C. parvum isolates from calves revealed endogenous stages of C. parvum on the brush border of the ileum. The high prevalence and intensive shedding of cryptosporidial oocysts by calves in farms examined in this study suggests that naturally infected calves may be significant reservoirs for C. parvum infections in man and wild animals.

[Evaluation of the efficiency of gemfibrozil in treating hyperlipidemia type IIb and IV]

Analysis of the efficacy and tolerability of gemfibrozil (Gevilon-Parke Davis) was performed including 29 patients aged 19-69 years with primary hyperlipoproteinemia (HLP) type IIb-16 persons, IV-13 persons. All patients got dietary recommendations and received gemfibrozil 450-900 mg/day for 3 months. In both types of HLP a significant reduction of serum cholesterol (TCh)--15.5% triglycerides (TG)--32.1% VLDL-Ch--34.9% and VLDL-TG concentration--36.6% was observed as well as an increase of HDL3 fraction-16.3%. The greatest reduction of serum TCh concentration and VLDL-Ch were observed in type IIb, while that of TG and VLDL-TG in type IV HLP. The best therapeutic effect was obtained during the first month of treatment. The percent of TCh, TG, VLDL-Ch, VLDL-TG reduction correlated with their initial level. Tolerability of gemfibrozil was very good. Only in 2 patients transient abdominal pain was observed.

The role of hyperinsulinemia in the development of lipid disturbances in nonobese and obese women with the polycystic ovary syndrome

In order to establish the role of insulin in the pathogenesis of lipid abnormalities in hyperandrogenic women with the polycystic ovary syndrome (PCO) 49 women aged 18 to 35 yr with a normal glucose tolerance test were studied. They were divided into two groups: 27 women with PCO (9 obese and 18 nonobese), and 22 healthy women (12 with simple obesity and 10 with normal body weight). In the PCO group, the fasting insulin levels and the insulin response to oral glucose load were higher than in the matched controls. Significantly lower levels of HDL2-cholesterol and higher levels of apolipoprotein B were observed in obese and non nonobese PCO patients. In obese women with PCO this was associated with lower levels of HDL-cholesterol and apolipoprotein A-I (Apo A-I), whereas the levels of total triglycerides and VLDL-triglycerides (VLDL-TG) were increased. Multiple regression analysis in PCO women, after adjustment for age, body mass index and the levels of insulin and sex hormones, showed a strong positive correlation between the fasting insulin levels and total triglycerides and VLDL-TG, while a negative correlation was found between fasting insulin levels and apo A-I. These results indicate that hyperinsulinemia may play a role in the development of lipid disturbances in women with the PCO.