Although mumps virus (MV) infection that induces bilaterally inflammatory reaction such as swelling and tenderness in parotid salivary glands is easily diagnosed, virological and serological investigations are needed for a final diagnosis of an atypical case that suggests MV infection accompanying solitary swelling of certain major salivary glands. In general, it can be serologically diagnosed as MV infection if the serum level of antibody raised against MV at the convalescence of the disease is increased by 4 times in comparison to that at the acute phase. It is considered a major drawback of this diawgnostic method that the final decision is not obtained until recovery from the disease. In the present communication, we describe two atypical cases of MV infection that was diagnosed by MV isolation from the saliva of patients in the initial phase of the disease.
Two adult patients, complaining of an unilateral swelling of parotid salivary gland, were examined in our clinic. Since we suspected virus infection, the saliva from these patients was inoculated into green monkey kidnkey Vero cells. Several days later, cytopathic change that seemed to be induced by virus infection, appeared in the inoculated monolayers. Examination of the cells with the indirect immunofluorescent antibody staining technique and transmission electron microscopy revealed that MV replicated in the inoculated Vero cells. Thus, these cases could be diagnosed as MV infection early, at the first visit to our clinic.
