Acute infectious mononucleosis and coincidental measles virus infection

Coinfection with EBV/CMV and other respiratory agents in children with suspected infectious mononucleosis

BACKGROUND

Numerous studies have shown that Epstein-Barr virus (EBV) and cytomegalovirus (CMV) can infect immunocompetent patients simultaneously with other agents. Nonetheless, multiple infections with other agents in EBV/CMV-infected children have received little attention. We conducted a retrospective study of children with suspected infectious mononucleosis. Peripheral blood samples were analyzed by indirect immunofluorescence to detect EBV, CMV and other respiratory agents including respiratory syncytial virus; adenovirus; influenza virus types A and B; parainfluenza virus types 1, 2 and 3; Chlamydia pneumoniae and Mycoplasma pneumoniae. A medical history was collected for each child.

RESULTS

The occurrence of multipathogen infections was 68.9%, 81.3% and 63.6% in the children with primary EBV, CMV or EBV/CMV, respectively, which was significantly higher than that in the past-infected group or the uninfected group (p < 0.001). Of the multipathogen-infected patients, the incidence of C. pneumoniae in children with primary infection was as high as 50%, significantly higher than in the other groups (p < 0.001). In the patients with multipathogen infection and EBV/CMV primary infection, fever, rash, lymphadenopathy, hepatomegaly, splenomegaly, atypical lymphocytes and abnormal liver function were more frequent and the length of hospital stay and duration of fever were longer than in other patients.

CONCLUSION

Our study suggests that there is a high incidence of multipathogen infections in children admitted with EBV/CMV primary infection and that the distribution of these pathogens is not random.

Measles cases in highly vaccinated population of Novosibirsk, Russia, 2000-2005

While the proportion of measles cases in vaccinees is expected to increase as vaccine coverage increases, such cases must be carefully investigated. The present study was conducted to examine possible contributions to vaccine failures (VFs) and to genetically characterize measles virus (MV) strains circulating in Novosibirsk, Russia during 2000-2005. Totally, 27 adult measles patients admitted to a regional hospital were prospectively enrolled in our study. Genetic characterization of the MV strains revealed circulation of genotypes A, D4 and D6 between 2000 and 2003 years; a genotype D6 MV was associated with the 2005 measles outbreak. Based on IgG avidity testing, half of the vaccinated patients demonstrated evidence of secondary vaccine failure (SVF). Patients, representing both levels of vaccine failure in our study were characterized by the lack of protective titers of neutralizing antibodies against circulating MVs, despite high IgG levels in many cases and high IgG avidity in SVF cases.

Measles in Minsk, Belarus, 2001–2003: Clinical, virological and serological parameters

BACKGROUND

A number of cases of measles have been reported in the Republic of Belarus despite vaccine coverage of 98%. The absence of information on measles virus genotypes circulating in the Republic of Belarus has made it difficult to asses the situation.

OBJECTIVES

The purpose of this study was to isolate and sequence measles virus strains from clinical cases in Minsk, Belarus, and to estimate the role of vaccine failure in those cases.

STUDY DESIGN

Between 2001 and 2003 years, 14 measles cases admitted to the Hospital of Infectious Diseases of Minsk were enrolled in our study. Clinical, routine laboratory, as well as serological and virological examinations were carried out. Detection of measles antibodies and IgG avidity testing was performed using commercial test kits. All measles cases were confirmed by RT-PCR and phylogenetically characterized.

RESULTS

Only 42.9% of the cases met the WHO laboratory criteria for measles, however, all cases were confirmed by RT-PCR. Most of the measles cases were attributed to secondary vaccine failure (SVF). Phylogenetic analysis revealed the presence of genotype A virus strains in 2001 and 2002 with D6 and D7 genotypes in 2003.

CONCLUSIONS

For the first time, MVs were genetically characterized in Belarus. Our results suggest that in a highly vaccinated population, most of measles cases represent vaccine failures and are vaccine-modified. Our results also indicate that confirmation of a clinical diagnosis of vaccine-modified measles requires a combination of serological and virological tests.