Simultaneous presence of human herpesvirus 6 and adenovirus infections in intestinal intussusception of young children.

AIM: This prospective study investigated the role of viral infections in the pathogenesis of intussusception, including human herpesvirus 6 (HHV-6), a known lymphotropic virus. METHODS: Fifty-three children with intussusception treated in hospital were enroled, and children of comparable age and gender served as controls. Blood, stool and throat swab specimens, as well as mesenteric lymph nodes and pieces of intestine from patients requiring surgery were tested for various viruses by PCR methods. RESULTS: Altogether, 85% of intussusception cases showed evidence of a recent or ongoing viral infection. Among the 53 intussusception cases, adenovirus was detected in 25 (47%), HHV-6 in 24 (45%), rhinovirus in 12 (23%), cytomegalovirus in 7 (13%), enterovirus in 4 (8%) and rotavirus in 3 (6%) patients. Of the 50 whole blood samples, 44% were positive for HHV-6 and of the 16 resected mesenteric lymph nodes, 50% were positive for HHV-6. Simultaneous presence of HHV-6 and adenovirus infection correlated significantly with intussusception (OR 12.1, 95% CI 2.2 to 66.5). CONCLUSIONS: A statistically significant association was observed between adenovirus and childhood intussusception. HHV-6 was a common finding and occurred concomitantly with other viruses. A simultaneous infection with HHV-6 and adenovirus carried the highest risk for intussusception.

Rotavirus gastroenteritis in Finnish children in 2006-2008, at the introduction of rotavirus vaccination.

Rotaviruses (RV) are major causative agents of acute gastroenteritis (AGE) requiring hospitalization in children; RV hospitalizations may be largely eliminated by universal mass vaccination with RV vaccine. We conducted a hospital-based prospective survey of AGE in children over 2 RV epidemic seasons, from 2006 to 2008, when the coverage of RV vaccination in Finland increased to 35% of the birth cohort. RVs were detected by reverse transcription polymerase chain reaction (RT-PCR). In the first season, only 38% of AGE cases were RV-positive, and the onset of the RV season was delayed. Type G1P[8], RVs accounted for 40%, G2P[4] for 19%, G3P[8] for 2%, G4P[8] for 2% and G9P[8] for 38%. In the second season, 63% of AGE cases were RV-positive: G1P[8] accounted for 73%, G2P[4] for only 3%, G3P[8] for 4%, G4P[8] for 13%, and G9P[8] had almost disappeared. G2P[4] RV did not become predominant at the coverage level of 29% of G1P[8] human RV vaccine. RV-associated hospitalizations were seen in children up to the age of 9 y. This study forms the epidemiological background for the follow-up of the impact of universal RV vaccination in Finland introduced in 2009.

Bordetella pertussis infection is common in nonvaccinated infants admitted for bronchiolitis.

BACKGROUND: Preliminary evidence suggests that viral-pertussis coinfections are common in nonvaccinated infants. SUBJECTS AND METHODS: Bordetella pertussis infection was studied by polymerase chain reaction in nasopharyngeal aspirates in 142 infants <6 months of age, who were admitted for bronchiolitis. Viral etiology,documented by antigen detection or polymerase chain reaction in nasopharyngeal aspirate, was respiratory syncytial virus (RSV) in 105, rhinovirus in 8, influenza A virus in 8, and other viruses in 10 cases. Only 11 samples were negative. RESULTS: B. pertussis infection was found in 12 (8.5%) cases, being coinfection with RSV in 8 (67%) cases (7.6% of all RSV infections). In a retrospective analysis, RSV-pertussis coinfections and sole RSV infections did not differ for the presence of cough. Preliminary evidence was found that a history of coughing spells was associated with B. pertussis identification. CONCLUSIONS: Coinfection with B. pertussis was present in 8.5% of <6-month-old infants, who were hospitalized for viral bronchiolitis. To avoid underdiagnosis, pertussis should be considered in all nonvaccinated infants admitted for lower respiratory tract infection.

Norovirus gastroenteritis in young children receiving human rotavirus vaccine.

We explored whether human rotavirus vaccine had any efficacy against norovirus (NV)-associated gastroenteritis in young children. In an efficacy trial of rotavirus vaccine, 405 infants were immunized with a human rotavirus vaccine or placebo at a ratio of 2:1, and prospectively followed for acute gastroenteritis (AGE) from approximately 2 months to 2 y of age. Multiplex real-time reverse transcription polymerase chain reaction (Mrt RT-PCR) assays were used for detection and quantitation of NVs of genogroup I (GI) and genogroup II (GII) in stool specimens. NVs were detected in 155 (32%) of 485 episodes of AGE. Of these, NV was the only gastroenteritis virus detected in the stools in 142 (29%) episodes. GI and GII NVs were found in 12% and 88% of the cases, respectively. NV as the only gastroenteritis virus was detected in 36% of the infants in the rotavirus vaccine group and 27% in the placebo group. The clinical severity of NV-associated AGE in the vaccine and placebo recipients was not different. NVs were the most common etiologic agents of AGE in children under 2 y of age. Human rotavirus vaccine did not protect against NV gastroenteritis.

Gene polymorphism of IFNG +874 T/A and TLR4 +896 A/G and recurrent infections and wheezing in toddlers with history of bronchiolitis.

Cytokine and TLR4 polymorphisms and their association with the infection history of 129 children hospitalized for bronchiolitis during the first 6 months of life were analyzed. The carriers of IFNG +874 T/A allele A had fewer infections and use of inhaled corticosteroids and the carriers of TLR4+896 A/G allele G were more likely to need tympanostomy than noncarriers.

IL-10 gene polymorphism at -1082 A/G is associated with severe rhinovirus bronchiolitis in infants.

We analyzed polymorphisms of IL-10 -1082 G/A, IL-18 -137 G/C, TLR4 +896 A/G, and IFNG +874 T/A in 139 infants under 6 months of age hospitalized with bronchiolitis and 400 unselected blood donors. Causative viruses were determined by PCR. Infants with bronchiolitis associated with a virus other than respiratory syncytial virus (N = 18), were more often IL-10 -1082 allele G non-carriers, that is, homozygous for allele A (AA) than controls (66.7% vs. 28.0%, P < 0.0001). Infants with RSV bronchiolitis did not differ from controls. This finding suggests a different pathogenic mechanism for RSV bronchiolitis as compared with wheezing associated with other viral infections, for example, rhinovirus in infants under 6 months of age.