Repeated high dose imidocarb dipropionate treatment did not eliminate Babesia caballi from naturally infected horses as determined by PCR-reverse line blot hybridization.

Imidocarb treatment of horses infected with Babesia caballi is supposed to eliminate the infection, but data on the efficacy of this treatment is scarce. The study presented here concerns four Paso Fino horses, which were imported into the island of Curacao on the basis of a piroplasmosis negative complement fixation test (CFT). Upon re-testing with an indirect fluorescent antibody test immediately after arrival in Curacao, two horses appeared to have antibodies to B. caballi and all horses had antibodies to Theileria equi. Subsequent testing with polymerase chain reaction combined with a reverse line blot yielded positive results for both agents in all four horses. Treatment with five consecutive doses of imidocarb dipropionate (4.7 mg/kg BW im q 72 h), temporarily resulted in negative results, but B. caballi and T. equi were detected again in the samples taken at 6 and 18 weeks after completion of the treatment. These results confirm that the CFT is not a suitable test for pre-import testing and that even high dose treatment with imidocarb may not be capable of eliminating B. caballi and T. equi infections from healthy carriers.

Host cell-specific protein expression in vitro in Ehrlichia ruminantium.

Ehrlichia ruminantium, a tick-transmitted pathogen, is the causative agent of heartwater in ruminants. In this study, a proteomic approach was used to identify host cell-specific E. ruminantium proteins encoded by the map1 multigene family, expressed in vitro in bovine endothelial and tick cell cultures. Two-dimensional gel electrophoresis combined with mass spectrometry analysis was used to establish the identities of immunodominant proteins. Proteins extracted from E. ruminantium-infected endothelial cells were shown to be products of the map1 gene, whereas tick cell-derived E. ruminantium proteins were products of a different gene, map1-1. The expressed proteins were found to be glycosylated. Differential expression of MAP1 family proteins in vitro in mammalian and tick cell cultures indicates that the map1 multigene family might be involved in the adaptation of E. ruminantium to the mammalian host and vector tick.

Molecular detection of Ehrlichia ruminantium infection in Amblyomma variegatum ticks in The Gambia.

In West Africa, losses due to heartwater disease are not known because the incidence/prevalence has not been well studied or documented. To develop a diagnostic tool for molecular epidemiology, three PCR-based diagnostic assays, a nested pCS20 PCR, a nested map1 PCR and a nested reverse line blot (RLB) hybridization assay, were evaluated to determine their ability to detect infection in vector ticks, by applying them simultaneously to A. variegatum field ticks to detect Ehrlichia ruminantium, the causative agent of heartwater. The nested pCS20 PCR assay which amplified the pCS20 gene fragment showed the highest detection performance with a detection rate of 16.6%; the nested map1 PCR, which amplified the gene encoding the major antigenic protein1 (map1 gene) showed a detection rate of 11% and the RLB, based on the 16S rDNA sequence of anaplasma and ehrlichial species, detected 6.2%. The RLB, in addition, demonstrated molecular evidence of Ehrlichia ovina, Anaplasma marginale and Anaplasma ovis infections in The Gambia. Subsequently, the pCS20 assay was applied to study the prevalence and distribution of E. ruminantium tick infection rates at different sites in five divisions of The Gambia. The rates of infection in the country ranged from 1.6% to 15.1% with higher prevalences detected at sites in the westerly divisions (Western, Lower River and North Bank; range 8.3-15.1%) than in the easterly divisions (Central River and Upper River; range 1.6-7.5%). This study demonstrated a gradient in the distribution of heartwater disease risk for susceptible livestock in The Gambia which factor must be considered in the overall design of future upgrading programmes.

Differential transcription of the major antigenic protein 1 multigene family of Ehrlichia ruminantium in Amblyomma variegatum ticks.

The rickettsial pathogen Ehrlichia ruminantium causes heartwater in ruminants and is transmitted by ticks of the genus Amblyomma. The map1 gene, encoding the major surface protein MAP1, is a member of a multigene family containing 16 paralogs. In order to investigate differential transcription of genes of the map1 multigene family in vivo in unfed and feeding ticks, RNA was extracted from midguts and salivary glands of E. ruminantium-infected adult female Amblyomma variegatum ticks and analysed by RT-PCR using MAP1 paralog-specific primers. In unfed ticks, only transcripts from the map1-1 gene were observed in midguts and no transcripts were detected in salivary glands. In feeding ticks, map1-1 transcripts were more abundant in midguts whereas high levels of map1 transcripts were observed in salivary glands. Our results show that differential transcription of genes of the E. ruminantium map1 cluster occurs in vivo in different tissues of infected ticks before and during transmission feeding, indicating that this multigene family may be involved in functions of biological relevance in different stages of the life cycle of E. ruminantium.

Risk factors predicting outcome in patients with pneumonia in Al-Ain, United Arab Emirates.

OBJECTIVE: To determine the predictive value of commonly used clinical and laboratory factors for mortality in patients with pneumonia in the Arab world. METHODS: We retrospectively analyze the data collected from all inpatients over the age of 16 years with a diagnosis of pneumonia in Tawam Hospital, Al-Ain, United Arab Emirates between the years 1997 and 2002. Patients were grouped into those who survived and those who died in the hospital. Clinical and laboratory factors on admission were used to predict outcome using simple, and multiple logistic regression analyses. RESULTS: Among the 236 patients admitted, 122 were females (age 56.9 +/- 23 years), and 114 males (age 58.5 +/- 23 years). The 30-day mortality rate was 10%. The most common comorbid risk factors were diabetes mellitus in 23.7% and chronic obstructive pulmonary disease in 19.5%. Of the 236 patients, 145 had sputum culture on admission. Simple logistic regression analysis showed increasing age, presence of comorbidity, low systolic blood pressure, confused mental status, low serum albumin, high serum creatinine, raised blood urea nitrogen and raised partial pressure of carbon dioxide at the time of admission were associated with higher mortality. On the Stepwise-multilogistic regression analysis, the most significant factors influencing mortality were: older age, altered mental status, low systolic blood pressure, low serum albumin and raised serum creatinine. Using a scoring system developed in the presence or absence of these risk factors, a score of >=100 predicted high risk for mortality. CONCLUSION: The in-hospital mortality rate for pneumonia was 10%. Older age, altered mental status, low systolic blood pressure, low serum albumin concentration and raised serum creatinine at admission were predictive of poor outcome in this cohort of patients.

[Autochthonous babesiosis in dogs in The Netherlands associated with local Dermacentor reticulatus ticks]. / Autochtone babesiose bij de hond in Nederland geassocieerd met lokale Dermacentor reticulatus teken.

In the spring and autumn of 2004, 20 respectively 3 cases of autochthonous canine babesiosis were diagnosed in the Netherlands, four of which ended fatally. Adult Dermacentor reticulatus ticks were found on four dogs. Case descriptions and diagnostics of this B. canis outbreak are discussed in more detail.