Previous studies have demonstrated that Thogoto virus is transmitted from infected to uninfected ticks when co-feeding on uninfected guinea-pigs, even though the guinea-pigs do not develop detectable viraemia. The dynamics of this 'non-viraemic transmission' were investigated. The percentage of nymphs (recipients) that acquired virus increased from zero, when co-feeding with infected adults (donors) for 3 d, to 80% for a co-feeding period of 5 d. No statistically significant difference was detected when infected donors and uninfected recipients were separated physically up to a maximum distance of approximately 160 mm. These results indicate that the temporal, but not the spatial, relationship affects the number of recipient ticks that become infected.

Animals↗

PubMedDate not supplied

Non-viraemic transmission of Thogoto virus: vector efficiency of Rhipicephalus appendiculatus and Amblyomma variegatum.

Previous studies have demonstrated that Thogoto virus is transmitted from infected to uninfected ticks when co-feeding on uninfected guinea-pigs, even though the guinea-pigs do not develop a detectable viraemia. Furthermore, tick to tick transmission is potentiated by factors associated with the salivary glands of ticks (saliva activated transmission). The vector efficiency of 2 ixodid tick species, Rhipicephalus appendiculatus and Amblyomma variegatum, for Thogoto virus was assessed using this model. The number of uninfected recipient ticks that acquired Thogoto virus when co-feeding with virus-infected ticks (donors) on uninfected guinea-pigs was determined. When nymphs of either tick species were employed as donors, there was no significant difference in the number of infected recipient nymphs. In contrast, a significant difference in the vector efficiency of adults ticks was observed: 77.0% of recipient ticks which co-fed with R. appendiculatus donor adults acquired Thogoto virus compared to 44.7% of recipient ticks which co-fed with A. variegatum donors. No significant difference in susceptibility to Thogoto virus infection was observed between recipient ticks of the 2 species. Thus, adults of R. appendiculatus are more efficient than A. variegatum in mediating non-viraemic transmission.

Animals↗

PubMedDate not supplied

Indirect trauma causing dislocation of the crystalline lens--a case report.

PURPOSE: To report a case of indirect trauma causing dislocation of the crystalline lens in a patient with no underlying risk factors. METHODS: Case report. RESULTS: A 76-year-old woman fell injuring her right temple area. She complained of blurring of vision in her right eye. Her vision was reduced to 6/60. Ocular examination revealed right aphakia associated with complete posterior dislocation of the crystalline lens into the vitreous cavity. No predisposing factors as pigment dispersion or pseudoexfoliation material was found on gonioscopy. CONCLUSIONS: Dislocation of the crystalline lens has been reported following direct trauma. It is known to occur spontaneously in mature and hypermature cataracts and in cases of weak zonules. Our case shows that indirect trauma can cause complete dislocation of the crystalline lens in the absence of any predisposing factors.

Accidental Falls↗

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