The appearance of cytomegalovirus (CMV) antigen positive blood leucocytes (CMV antigenaemia) was investigated in 52 renal transplant recipients during the first three months after transplantation. Using a mixture of three monoclonal antibodies, CMV (immediate early) antigens were detected in cytocentrifuged blood leucocytes within 3-5 h after sampling. The results were related to virus isolation from buffy coats (CMV viraemia), serology with a sensitive enzyme-linked immunosorbent assay (ELISA), and clinical symptoms of CMV disease. The antigen test was positive in all 14 patients with CMV viraemia, in 25 out of 27 of patients with serological evidence of primary or secondary CMV infection, and in 2 out of 25 patients without active infection. In patients with a clinical CMV syndrome the presence of CMV antigen (CMV-Ag) positive blood cells correspond with the period of signs and symptoms. CMV antigens were not detected in 23 out of 25 patients without active infection, nor in healthy controls and patients with other herpesvirus infections. CMV-Ag positive blood cells appeared, on average, nine days before serological signs of active infection. This method provides a rapid and sensitive approach to CMV detection, enabling early clinical diagnosis and subsequent tapering of immunosuppression or commencement of antiviral therapy.

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In a prospective study, 139 serial blood samples from 15 transplant recipients were assessed for the presence of cytomegalovirus (CMV) by virus isolation (CMV viremia) and by direct staining of CMV antigens (CMV Ag) in blood leukocytes (CMV antigenemia). CMV was isolated from 23 samples, whereas CMV Ag was detected in 44 specimens. All positive samples were from a total of nine patients who were diagnosed as having active CMV infections. In seven patients, active CMV infections were diagnosed by virus isolation from blood and urine and by a significant rise of CMV-specific antibodies. In these patients, 21 of the 23 blood samples which were positive for CMV by cell culture were also positive by direct CMV Ag detection. Moreover, CMV Ag were detected in 23 of the 116 culture-negative samples. Twenty of these samples were from the acute phase of infection in the same seven patients. The remaining three CMV Ag-positive specimens were from the other two patients, from whom CMV was not isolated but who had serological evidence of concomitant active CMV infections. These results suggest that direct detection of CMV Ag in peripheral blood leukocytes is as specific as and more sensitive than current isolation techniques. Furthermore, by its sensitivity and inherent rapidity the antigen detection test proved to be the earliest diagnostic marker of active CMV infection in eight of the nine patients. Finally, it was shown that monoclonal antibodies to CMV immediate early antigens are a prerequisite for demonstration of CMV antigenemia.

Experimental herpes simplex virus type 1 (HSV-1) labyrinthitis provides a model of idiopathic sudden sensorineural hearing loss (ISSHL). Corticosteroids improve the prognosis for hearing recovery in ISSHL, but the effects of acyclovir are unknown. To establish the therapeutic efficacy of acyclovir (Zovirax) and prednisolone in experimental HSV-1 viral labyrinthitis, we induced HSV-1 labyrinthitis in 12 guinea pigs. Three animals received no treatment, 3 received prednisolone, 3 received acyclovir, and 3 received both. Four other animals served as controls, receiving culture medium only. Hearing, HSV-1 antibody titers, and cochlear damage were evaluated. The HSV-1 labyrinthitis caused hearing loss within 24 hours. Combination treatment consisting of prednisolone and acyclovir resulted in earlier hearing recovery and less extensive cochlear destruction compared to prednisolone or acyclovir as a monotherapy. The beneficial effect of this treatment modality remains to be demonstrated in ISSHL.

To determine whether certain Chlamydia trachomatis serovars are preferentially associated with a symptomatic or an asymptomatic course of infection, C. trachomatis serovar distributions were analyzed in symptomatically and asymptomatically infected persons. Furthermore, a possible association between C. trachomatis serovars and specific clinical symptoms was investigated. C. trachomatis-positive urine specimens from 219 asymptomatically infected men and women were obtained from population-based screening programs in Amsterdam. Two hundred twenty-one C. trachomatis-positive cervical and urethral swabs from symptomatically and asymptomatically infected men and women were obtained from several hospital-based departments. Serovars were determined using PCR-based genotyping, i.e., restriction fragment length polymorphism analysis of the nested-PCR-amplified omp1 gene. The most prevalent C. trachomatis serovars, D, E, and F, showed no association with either a symptomatic or asymptomatic course of infection. The most prominent differences found were (i) the association of serovar Ga with symptoms in men (P ‫؍‬ 0.0027), specifically, dysuria (P < 0.0001), and (ii) detection of serovar Ia more often in asymptomatically infected people (men and women) (P ‫؍‬ 0.035). Furthermore, in women, serovar K was associated with vaginal discharge (P ‫؍‬ 0.002) and serovar variants were found only in women (P ‫؍‬ 0.045).

A cooperative study was conducted among six laboratories to compare the performance of the Cobas Amplicor (CA) polymerase chain reaction (PCR) system (Roche Molecular Systems, USA) for the detection of Mycobacterium tuberculosis with that of microscopy and culture in routine clinical laboratory diagnosis. A total of 5,221 decontaminated respiratory specimens were tested. The use of an internal control allowed detection of PCR inhibition in 144 (2.8%) specimens. Only two culture-positive samples were CA PCR inhibitory and therefore could not be detected by PCR testing. Of the 333 culture-positive specimens, 278 (83.5%) were positive by the CA PCR. Of the 4,744 culture-negative specimens, 52 (1.1%) were positive by the CA PCR. After analysis of discrepancies, 40 of the 52 culture-negative, CA PCR-positive specimens were classified as true positive. Thus, the overall sensitivities of culture, CA PCR and microscopy were 89.3%, 85.2% and 55.5%, respectively. The overall specificity of the CA PCR was 99.7%. Five of the six centers found similar performances for the CA PCR, with sensitivities ranging from 85.7 to 90.9%. The CA PCR was more sensitive for smear-positive samples, exhibiting overall sensitivities of 96.1% and 71.7% for smear-positive and smear-negative specimens, respectively. These results indicate that the Cobas Amplicor system enables microbiology laboratories with reasonable previous experience in molecular biology testing to perform PCR and to detect Mycobacterium tuberculosis in more than 70% of specimens obtained from infected patients.

Bell's palsy, which is defined as idiopathic peripheral facial paralysis of sudden onset, accounts for >50% of all cases of facial paralysis. Different theories on the etiology of Bell's palsy have been proposed and investigated. Various clinical studies have suggested an etiological link between Bell's palsy and herpes simplex virus (HSV). In addition, animal experiments have shown the ability of HSV to induce facial paralysis. In our opinion, the possible link between Bell's palsy and HSV can only be explored properly by studying the human facial nerve, and especially the geniculate ganglion itself. Different groups have tried to detect hypothetically reactivated and hypothetically latent HSV in the facial nerves of Bell's palsy patients and control patients, respectively. The isolation of infectious HSV from facial nerve tissue by conventional cell culture methods appeared to be very difficult, also when Bell's palsy patients were tested. Instead, modern molecular methods, such as in situ hybridization and the polymerase chain reaction (PCR) could easily detect HSV DNA in geniculate ganglia. The detection of HSV‐specific latency‐associated transcripts in the ganglia of control patients provided further evidence for the hypothetically latent state of HSV in the geniculate ganglia in these patients. Recent PCR experiments performed by a Japanese group strongly suggest that the area adjacent to the geniculate ganglia does not usually contain any HSV at all, except in patients with Bell's palsy. This well‐controlled study provides conclusive evidence that reactivation of HSV genomes from the geniculate ganglia is the most important cause of Bell's palsy. Consequently, it has been suggested that “Bell's palsy” be renamed as “herpetic facial paralysis”.

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