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Biomedical subjects

F Jongejan

Publications and source records attributed to F Jongejan.

At least 19 recordsLinked to original sources
PubMed2006

The known distribution and ecological preferences of the tick subgenus Boophilus (Acari: Ixodidae) in Africa and Latin America.

A compilation of the known distribution of Boophilus ticks in Africa and Latin America is presented, together with details on climate preferences. B. annulatus is recorded mainly in the western part of a strip from the equator to parallel 20 degrees N. It associates with woodlands and forests (lowland rain forest and secondary grassland). This species is also present in the Mediterranean region, associated to woodland and open areas. B. decoloratus extends southern to parallel 20 degrees N, in woodland with montane vegetation and Zambezian miombo; some records have been collected in the highveld grassland. B. geigyi is mainly collected in the western range of a stripe extending between parallels 5 degrees N and 18 degrees N, associated with Sudanian woodland, lowland rain forest with secondary grassland and woodland. Confirmed records of microplus in Africa are restricted to Malagasy region and south and eastern Africa, being predominant in the Zambezian miombo, deciduous forest with secondary grassland, and woodland. In Latin America, microplus is abundant in the Mesoamerican corridor to Venezuela and Colombia, and southern in Brazil and Argentina. The tick is mainly associated to the biomes of Chaco and Pampas in Argentina, the North-central moist Andes, the Atlantic forest (southern range) and the moist Meso-American vegetation (northern range). Most collections of B. annulatus and B. geigyi came from areas where winter minimum temperature is above 15 degrees C, maximum temperatures remain between 33 and 36 degrees C and maximum rainfall is recorded between June and September. B. decoloratus and African B. microplus are recorded in sites with low temperatures in May-September. Minimum temperature requirements are similar for both B. decoloratus and African B. microplus, and both are around 4 degrees C less than the value recorded for collections of Latin-American B. microplus. The rainfall pattern observed for decoloratus shows a minimum in May and June. The requirements of total rainfall are highest for B. microplus in Latin America, while records of African B. microplus are concentrated in areas of low rainfall between May and October, and high rainfall between November and March (low rainfall in the same period for B. decoloratus). Statistical analysis revealed the existence of populations (demes) with ecologically different requirements within each tick species. Both B. annulatus and B. decoloratus showed many different demes clearly associated to defined areas. The collections of Latin American B. microplus are very homogeneous according climate preferences and well separated from the African counterpart.

Africa↗
PubMed2005

Molecular and serological detection of A. centrale- and A. marginale-infected cattle grazing within an endemic area.

A reverse line blot hybridization (RLB) one-stage nested PCR (nPCR) for Anaplasma centrale and a nested PCR for Anaplasma marginale were used to detect infected cattle grazing within an endemic region in Israel. A novel set of PCR primers and oligonucleotide probes based on a 16S ribosomal RNA gene was designed for RLB detection of both Anaplasma species, and the performance of the molecular assays compared. The immunofluorescent antibody test (IFA) was used to detect antibodies to both Anaplasma species, whereas, a highly sensitive and specific competitive enzyme-linked immunosorbent assay (cELISA) was used to detect antibodies in A. centrale-vaccinated cattle. The RLB and the nested PCR procedures showed bacteremia with sensitivity of 50 infected erythrocytes per milliliter. Up to 93% of the A. centrale vaccinates carried specific antibodies that were detected by cELISA, and up to 71% of the vaccinated cattle were found to be naturally infected with A. marginale according to the PCR and the RLB assays. Nevertheless, no severe outbreaks of A. marginale infection occurred among vaccinated herds in this endemic region. It appears that both, molecular tools and serology are useful for evaluation of the vaccine efficacy. In the light of wide natural field infection with A. marginale, strong recommendations to continue the A. centrale vaccination program regime will continue until a new generation of non-blood-based vaccine will be developed.

Anaplasma centrale↗
PubMed2005

Molecular characterization of Theileria species associated with mortality in four species of African antelopes.

Pathogen DNA was isolated from roan antelope (Hippotragus equinus), sable antelope (Hippotragus niger), greater kudu (Tragelaphus strepsiceros), and common gray duiker (Sylvicapra grimmia) in South Africa whose deaths were attributed to either theileriosis or cytauxzoonosis. We developed Theileria species-specific probes used in combination with reverse line blot hybridization assays and identified three different species of Theileria in four African antelope species. The close phylogenetic relationship between members of the genera Theileria and Cytauxzoon, similarities in the morphologies of developmental stages, and confusion in the literature regarding theileriosis or cytauxzoonosis are discussed.

Animals↗
PubMed2005

Borrelia burgdorferi infections with special reference to horses. A review.

This review discusses the literature on B. burgdorferi infections in view of the rising incidence of this infection in general and the increasing concerns of horse owners and equine practitioners. Lyme disease, the clinical expression of Borrelia infections in man is an important health problem. The geographic distribution of B. burgdorferi infections in equidae should resemble that of human cases because the vector tick involved, Ixodes ricinus, feeds on both species and, indeed, the infection has been established many times in horses. However, a definite diagnosis of the disease "Lyme borreliosis" in human beings as well as in horses and other animals is often difficult to accomplish. Although a broad spectrum of clinical signs has been attributed to B. burgdorferi infections in horses, indisputable cases of equine Lyme borreliosis are extremely rare so far, if they exist at all.

Animals↗
PubMed2004

Confirmation of occurrence of Babesia canis vogeli in domestic dogs in South Africa.

The prevalence of Babesia infections in domestic dogs in South Africa was studied using reverse line blot hybridization and 18S sequence analysis. Babesia canis vogeli was confirmed for the first time in domestic dogs in South Africa. Out of a total of 297 blood samples collected from domestic dogs in Bloemfontein, East London, Johannesburg, Durban and from the Onderstepoort Veterinary Academic Hospital, 31 were positive for Babesia canis rossi, whereas B. c. vogeli was detected in 13 dogs. None of the dogs carried both parasites. The detection of B. c. vogeli has implications with regard to prevalence and varied clinical manifestation of canine babesiosis in South Africa.

Animals↗
PubMed2004

The global importance of ticks.

Ticks and tick-borne diseases affect animal and human health worldwide and are the cause of significant economic losses. Approximately 10% of the currently known 867 tick species act as vectors of a broad range of pathogens of domestic animals and humans and are also responsible for damage directly due to their feeding behaviour. The most important tick species and the effects they cause are listed. The impact on the global economy is considered to be high and although some estimates are given, there is a lack of reliable data. The impact of ticks and tick-borne diseases on animal production and public health and their control are discussed.

Animals↗
PubMed2004

Endemic stability for Theileria parva infections in Ankole calves of the Ankole ranching scheme, Uganda.

A population-based study was carried out on the Ankole ranching scheme in south-west Uganda with the aim of determining the endemic status of Theileria parva infections. For this purpose, the age-related sero-prevalence of T. parva and the specific calf mortality associated with the parasite were assessed. Blood samples were collected from 931 Ankole calves of up to 12 months of age from 81 randomly selected herds. The relationship between rainfall pattern and whole-body Rhipicephalus appendiculatus counts was determined. The influence of tick control practices on East Coast fever-related calf mortality, and sero-positivity were also determined. A significant (r2 = 0.76, P = 0.000) association between R. appendiculatus counts and rainfall was observed. There was no significant (P > 0.05) association between theileriosis-related calf mortality, sero-positivity and the different tick control practices. Antibody prevalence based on the PIM ELISA was above 70% among calves of 6 months of age in 96% in all the herds. Theileria parva-related calf mortality determined by repeated herd visits and farm records ranged between 0 % and 5.4 %. It was concluded that endemic stability for theileriosis, caused by T. parva, existed in the study area, and that the risk of the occurrence of economically important outbreaks of East Coast fever in indigenous cattle was regarded as minimal under the prevailing conditions.

Animals↗
PubMed2004

Preliminary survey of ticks (Acari: Ixodidae) on cattle in northern Sudan.

In a cross sectional survey conducted during the period June 2001 to July 2002, the geographical distribution of ticks on cattle in the Sudan was determined. Seventeen locations were surveyed from Northern, Central, Eastern, Western, Blue Nile and White Nile Provinces. Total body collections of ticks were made from 20 cattle at each location. Four tick genera and 11 species were identified. The tick species collected included Amblyomma lepidum, Amblyomma variegatum, Boophilus decoloratus, Hyalomma anatolicum anatolicum, Hyalomma dromedarii, Hyalomma impeltatum, Hyalomma marginatum rufipes, Hyalomma truncatum, Rhipicephalus evertsi evertsi, Rhipicephalus sanguineus group and Rhipicephalus simus simus. Major ecological changes have occurred due to extensive animal movement, deforestation, desertification and establishment of large mechanized agricultural schemes. These factors have certainly affected the distribution of ticks and tick-borne diseases in the Sudan. The absence of A. variegatum and A. lepidum in northern Sudan was not surprising, since these tick species are known to survive in humid areas and not in the desert and semi-desert areas of northern Sudan. The absence of B. annulatus in northern and central Sudan is in accordance with the finding that this tick species is restricted to the southern parts of the central Sudan. The presence of H. anatolicum anatolicum in Um Benin in relatively high abundance is an interesting finding. The present finding may indicate that the southern limit of this species has changed and moved southwards to latitude 13 degrees N. It is concluded that major changes in tick distribution have taken place in the Sudan.

Animal Husbandry↗
PubMed2003

A fatal case of human babesiosis in Portugal: molecular and phylogenetic analysis.

We report the first case of human babesiosis in Portugal. A 66-year-old splenectomized man was admitted to a Lisbon hospital after 1 week of fever, abdominal pain, anorexia and nausea. A high parasitaemia (30%) of Babesia parasites was found in Giemsa-stained blood smears and, despite treatment, the patient died several weeks later of renal failure. Ethylenediaminetetraacetic acid blood samples were processed for polymerase chain reaction (PCR) and reverse line blot hybridization to confirm and characterize the Babesia infection. The amplified PCR product was cloned and subsequently sequenced. Molecular analysis showed that the infection was caused by Babesia divergens and that other blood parasites were not involved. Phylogenetic analysis showed that the 18 S ribosomal RNA gene sequence was similar to three other European isolates of B. divergens. In view of the high risk for splenectomized individuals, strict measures should be taken to avoid tick bites.

Aged↗
PubMed2002

Seasonal epidemiology of ticks and aspects of cowdriosis in N'Dama village cattle in the Central Guinea savannah of Côte d'Ivoire.

In the Central Guinea savannah of Côte d'Ivoire, cattle breeding started only approximately 30 years ago. The impact of parasitism on the overall health status and productivity of the trypanotolerant N'Dama cattle in this area is unknown. In close collaboration with national veterinary institutions and local farmers, we studied spectrum, burden and seasonal dynamics of ticks (including aspects of cowdriosis) on N'Dama village cattle. In a longitudinal study, three randomly selected cattle herds (traditional farming type) of one village were examined repeatedly for ticks. Spectrum, burden, seasonal epidemiology of ticks were assessed. In these traditional herds (which lack (ecto)parasite management), all animals were infested by ticks at monthly counts. Five different tick species were identified; the four genera in order of frequency were: Amblyomma (overall prevalence 96%), Boophilus (47%), Hyalomma (<1%) and Rhipicephalus (<1%). Amblyomma variegatum was the most-abundant tick on cattle in all seasons. Seroprevalence of Cowdria ruminantium was 31% (95% CI: 26, 36%). Most of the animals typically carried low tick burdens. N'Dama cattle seem well adapted to their environment and can resist the tick burdens under this traditional farming system.

Animals↗
PubMed2002

Susceptibility of bovine umbilical cord endothelial cells to bovine herpesviruses and pseudocowpox virus.

The purpose of the study was to determine the susceptibility of bovine umbilical cord endothelial (BUE) cells to bovine herpesvirus (BHV) 1, BHV2, BHV4 and BHV5, and to pseudocowpox virus. The detection limits and growth curves of these viruses in BUE cells were compared with those in Vero, Madin-Darby bovine kidney (MDBK). or bovine fetal diploid lung (BFDL) cells. Detection limits were determined by inoculating cell cultures with serial 10-fold dilutions of these viruses, and growth curves by titration of virus, harvested at various times after infecting cells at a multiplicity of infection of 0.1. The detection limits of BHV2 and BHV4 were lower in BUE cells than in Vero or MDBK cells, and cytopathic effects were observed earlier in BUE cells. In addition, BHV2 and BHV4 grew to higher titres in BUE cells than in Vero or MDBK cells. BUE cells appeared to be equally susceptible to BHV5, but less susceptible to BHV1.1 and BHVI.2 than MDBK cells. The study showed that BUE cells are highly susceptible to BHV2 and BHV4. and that the use of BUE cells can improve the laboratory diagnosis of these viruses. The use of BUE cells could also improve the isolation and growth of pseudocowpox virus.

Animals↗
PubMed2001

Detection of haemoparasites in cattle by reverse line blot hybridisation with a note on the distribution of ticks in Sicily.

A reverse line blot hybridisation (RLB) of 21 oligonucleotides with polymerase chain reaction (PCR) amplified regions of 16S rRNA (Ehrlichia/Anaplasma group) or 18S rRNA (Babesia/Theileria group) genes of haemoparasites detected Theileria annulata, T. buffeli/orientalis, Babesia bovis, B. bigemina, B. divergens, Ehrlichia bovis, Anaplasma marginale, A. centrale and unknown species within the Rickettsia tribe.A very high prevalence of mixed infections was detected, which indicated that animals infected with Babesia spp. were also infected with Theileria spp. and/or Anaplasma spp. The tick distribution appeared to be seasonal with Hyalomma marginatum as the most frequently observed tick and Boophilus annulatus and Ixodes ricinus as the least frequently observed ticks. Other species identified in the 818 ticks collected during the five sampling periods between April 1998 and November 1999 included H. lusitanicum, Rhipicephalus sanguineus group, R. bursa, Dermacentor marginatus, Haemaphysalis punctata, B. annulatus and I. ricinus.

Anaplasma↗
PubMed2001

Dynamics of IgG1 and IgG2 subclass response in dogs naturally and experimentally infected with Ehrlichia canis.

Immunoglobulin (Ig) G subclasses were measured in dogs naturally and experimentally infected with Ehrlichia canis using enzyme-linked immunosorbant assay (ELISA). In this study, a higher IgG2 subclass response was noticed to natural and experimental E. canis infection in dogs. Anti-E. canis-IgG2 optic density (OD) values were found to be significantly higher than anti-E. canis-IgG1 during the different phases of the disease, and no differences in the IgG subclass responses to E. canis infection were found between symptomatic and asymptomatic dogs. Doxycycline treatment, which eliminated the rickettsia in three of four persistently infected dogs, had no noticeable influence on the E. canis-IgG subclass OD values during the treatment period. In order to facilitate the study, an ELISA for the detection of anti-E. canis IgG was developed and was shown to be sensitive and specific for E. canis-IgG, and in a significant correlation with the indirect immunofluorescence antibody test.

Animals↗
PubMed2001

Significance of serological testing for ehrlichial diseases in dogs with special emphasis on the diagnosis of canine monocytic ehrlichiosis caused by Ehrlichia canis.

Dogs are susceptible to a number of ehrlichial diseases. Among them, canine monocytic ehrlichiosis is an important and potentially fatal disease of dogs caused by the rickettsia Ehrlichia canis. Diagnosis of the disease relies heavily on the detection of antibodies and is usually carried out using the indirect immunofluoresence antibody (IFA) test. The IFA test may be confounded by cross-reactivities between a number of the canine ehrlichial pathogens. This article presents a review of the ehrlichial diseases affecting dogs with reference to their immune responses, host specificities, cross-reactivites and diagnosis. Diagnostic means such as Western immunblot, dot-blot and PCR are discussed. The use of the IFA test as a diagnostic means for E. canis is presented along with its potential pitfalls. The review emphasizes that the disease process, cross-reactivites with other ehrlichial species, multiple tick-borne infections and persistent IFA antibody titers post-treatment, should all be considered when interpreting E. canis serological results.

Animals↗
PubMed2001

Study of Theileria annulata population structure during bovine infection and following transmission to ticks.

Tams1 is the polymorphic immunodominant merozoite-piroplasm surface protein of Theileria annulata. Evidence for selection of divergent forms of Tams1 has been obtained recently. This study was performed to address whether selection takes place during persistent infection of the bovine host or during passage through the Hyalomma tick vector. Four calves were infected with a T. annulata isolate representing multiple parasite genotypes. The development of the parasite population was analysed by denaturing gradient gel electrophoresis (DGGE) using the Tams1 gene as a marker. In addition, the parasitaemia was measured by a semi-quantitative reverse line blot hybridization assay in order to correlate Tams1 variation to changes in parasitaemia. It was found that both parasitaemia and parasite population displayed limited variation during persistent infection. Ticks were allowed to acquire T. annulata during 2 periods of the bovine infection. Tams1 alleles detected in ticks fed during acute infection were identical to the population in the bovine host. However, ticks fed during the carrier status acquired parasites showing a single Tams1 isotype that represented, in several cases, a minor population in the bovine host at the time of infestation. Although only a limited number of ticks were studied, these preliminary data suggest that specific parasite genotypes may be selected during tick transmission from a carrier animal.

Animals↗
PubMed2001

Evidence for the utility of the Bm86 antigen from Boophilus microplus in vaccination against other tick species.

The Bm86 antigen, as originally identified in Boophilus microplus, is the basis of commercial tick vaccines against this tick species. The potential for using this antigen or homologues of the antigen in vaccination against other tick species has been assessed. We have conducted vaccine trials in cattle using the B. microplus-derived recombinant Bm86 vaccine (TickGARD) using pairs of vaccinated calves and control calves. These were infested with B. microplus and Boophilus decoloratus larvae simultaneously. For both species, the numbers of engorged female adult ticks, their weight and egg-laying capacity were all reduced, leading to a reduction in reproductive capacity of 74% for B. microplus and 70% for B. decoloratus. Hyalomma anatolicum anatolicum ticks were fed both as immatures as well as adults on vaccinated calves and non-vaccinated controls. There was an overall 50% reduction in the total weight of nymphs engorging on vaccinated calves, and a suggestion of a subsequent effect on feeding adults. For Hyalomma dromedarii there was a 95% reduction in the number of nymphs engorging and a further 55% reduction in weight of those ticks surviving. Rhipicephalus appendiculatus and Amblyomma variegatum ticks were fed simultaneously both as immatures and subsequently as adults. There was no evidence for a significant vaccination effect. Finally, the amino acid sequence of a Bm86 homologue found in H. a. anatolicum unequivocally demonstrated the conservation of this molecule in this species. Our strategy for the development of multivalent anti-tick vaccines is discussed in relation to these findings.

Amino Acid Sequence↗