To characterize patients with mumps vaccine failure, avidity testing was performed with the Enzygnost Anti-Parotitis Virus/IgG kit using a single-dilution–6 M urea denaturation method. Five groups of patients were tested. Group 1 consisted of 29 patients with primary mumps infections; group 2 was 20 children and adults with a definite history of natural infection; group 3 was 7 patients with a recent mumps vaccination, 1 of whom developed parotid gland swelling and aseptic meningitis; group 4 was 14 patients with mumps vaccine failure; and group 5 was 6 patients with recurrent episodes of parotitis in addition to a history of vaccination. On the basis of the results of groups 1 and 2, an avidity of ≦31% was determined to be low, and ≧32% was determined to be high. Avidity maturation from low to high appears to occur around 180 days after the acute illness. The results of group 3 showed that the vaccine-induced immunoglobulin G (IgG) had very low avidity. Among the 14 patients in group 4, 12 patients, including 7 with a positive IgM response, were diagnosed as having secondary vaccine failures. The results of group 5 suggested the possibility that the avidity of the mumps vaccine-induced IgG remains low or borderline. These results showed that secondary mumps vaccine failure occurs not infrequently, even among school age children under condition in which the vaccine coverage is low (i.e., 33% in our study population), and therefore, vaccinees are prone to be exposed to wild-type viruses. Avidity testing should provide information useful for the analysis of mumps virus infections.

No abstract

To determine whether mycoplasmal bacteremia occurs during ordinary or complicated diseases due to M. pneumoniae (and if so, how frequently), we used polymerase chain reaction (PCR) to detect M. pneumoniae in serum samples. The PCR primers used were modified for nested amplification. The genome of this organism was detected in 1 of the 25 patients with pneumonia and 10 of the 17 patients without pneumonia (P < .001, chi test). The genome was detected more frequently in patients who had encephalitis of which the neurological onset was within 7 days of the onset of fever rather than later. We hypothesize that mycoplasmal bacteremia occurs more frequently than previously appreciated, specifically in the absence of pneumonia, and that certain types of complications (e.g., encephalitis of early onset) are associated with its occurrence.

Summary. Multicentric Castleman's disease (MCD), also called multicentric angiofollicular lymphoid hyperplasia, is a systemic lymphoproliferative disorder causing fever, lymphadenopathy and splenomegaly. Recently, Kaposi's sarcoma-associated herpesvirus/human herpesvirus 8 (KSHV/HHV-8) DNA sequences have been detected in cases of MCD. We examined HHV-8 DNA sequences in the peripheral blood mononuclear cells (PBMCs) of two HIVnegative patients with MCD and in PBMCs and the lymph node of a HIV-negative patient with localized Castleman's disease (LCD) by the polymerase chain reaction. The novel sequences were detected in all DNA samples. Furthermore, the sequences were detected in only the CD19 þ Blymphocyte fraction of the patient with LCD as previously reported. However, the sequences were detected in CD19 þ B-lymphocyte and CD2þ T-lymphocyte fractions of two patients with MCD. These results suggest that HHV-8 has tropisms for both B lymphocytes and T lymphocytes in Castleman's disease.

Ten pediatric patients with mycoplasmal pleuritis were tested for the presence of Mycoplasma pneumoniae in pleural fluid by the polymerase chain reaction (PCR). Three of the four PCR positive cases left a persistent consolidation. The remaining one was an infant who required mechanical ventilation. PCR may be useful in predicting delayed resolution of roentgenographic abnormality. (Arch Dis Child 1998;78:67-69)