Bartonella clarridgeiae and B. henselae in Dogs, Gabon

Emerging Infectious Diseases • www.cdc.gov/eid • Vol. 10, No. 12, December 2004 2261 and Hep-2C derive from the same tissue (human Caucasian larynx carcinoma), while Vero and BGM derive from another organ (Africa green monkey kidney). Thus, Hep-2 and Vero cell lines that we used are likely susceptible to TSV if the virus can infect Hep-2C and BGM as reported by Audelo-del-Valle et al. The difference between our methods and those used by Audelo-delValle et al. may explain the discrepant result. If CPE occurred “usually from 19–23 hours” and “cells were then harvested and lysed” for next injection, TSV most likely persisted in the lysate after the third passage because the cell monolayers had not been washed as they were in our method. According to the time the CPE was observed and the methods of Audelodel-Valle et al., we assumed that, in their study, cells might be passaged at least three times within 1 week, whereas TSV might remain viable and infective for 1 week. Additionally, the Office International des Epizooties recommended an injection volume of 1% of shrimp body weight (8); Audelo-del-Valle et al. used 10%. With such a large dose, shrimp could be infected easily with TSV from the initial medium and die suddenly. Moreover, the evidence of successful infection from photos of CPE only is not sufficient; Audelo-del-Valle et al. should offer more convincing evidence from images of viral particles in cells by electron microscope or in situ hybridization. Therefore, we think the CPE that Audelo-del-Valle et al. reported was not caused by TSV but by a virus contaminant or some harmful component from shrimp extract. The structure of the TSV genome is similar to that of small insect–infecting RNA viruses (10), which belong to a renamed virus genus, Cripavirus (11). No published reports have shown that other viruses in this genus are able to infect mammalian cells or cell lines. Moreover, TSV is prevalent in shrimp farming areas in the world, and L. vannamei (principal host for TSV) are eaten by people worldwide (8). In China, some persons eat fresh shrimp without disinfecting them; however, no evidence shows that TSV can infect humans. The results of our study show that TSV cannot infect mammalian cell lines or cells.