[Pertussis in fully vaccinated infants and children. Are new vaccination strategies required?]. / Tos ferina en lactantes y niños bien vacunados. ¿Son necesarias nuevas estrategias de vacunación?

OBJECTIVE: To analyse the vaccination status of children diagnosed with pertussis and to compare the clinical manifestations of fully vaccinated with unvaccinated, or incompletely-vaccinated, children. METHODS: The clinical histories and vaccination cards of patients under 16years of age seen in the Emergency Room of the University Hospital Vall d'Hebron, Barcelona (Spain), for pertussis confirmed by a microbiological study were reviewed. The study period lasted from January 1, 2009 to December 31, 2011. RESULTS: Two hundred and twelve cases were studied: 35 in 2009, 28 in 2010 and 149 in 2011. RT-PCR was positive in 210 patients, and 73 had a positive culture. Infants under 6months of age account for 36.8% of all cases. Forty-four patients (21.5%) were not vaccinated. Forty-four (21.5%) children were between 2 and 5months of age and had received 1-2vaccine doses. One hundred and seventeen (57%) children were fully vaccinated; 76.9% (90cases) had received the last dose less than 4years ago. When clinical manifestations of the fully vaccinated patients were compared with those of the non-vaccinated or incompletely-vaccinated children, only cyanosis was found with a higher frequency in the latter group (P<.001). The age-adjusted probability of hospitalisation was significantly associated with non-vaccination (P=.001). The case mortality rate among inpatients was 1.3%. CONCLUSIONS: The number of pertussis cases seen in our centre has risen significantly in the last year. More than half (57%) of the patients were fully vaccinated, and 76.9% had received the last dose in the previous 4years. Other vaccination strategies, such as vaccination of adolescents, adults, and pregnant women, as well as a cocoon strategy are required to protect infants under 6months of age. More effective vaccines need to be developed.

[Microbiological diagnosis of mycoplasma infections]. / Diagnóstico microbiológico de las infecciones por Mycoplasma.

The microbiological diagnosis of mycoplasma and ureaplasma infections has always been limited due to the fastidious growth of these microorganisms, as well as the lack of commercially prepared growth media, absence of rapid diagnostic procedures, and the clinical perception that these organisms are less significant in the infectious diseases setting. During the last few years, this situation has substantially improved due to the commercial availability of culture media, the development of rapid serological techniques, and, in particular, to the introduction of nucleic acid amplification assays, commercially available or "in-house" preparations. Despite the lack of proper standardisation and validation of the molecular and serological techniques, methodological advances have led to an increased detection of these microorganisms and, consequently, a greater appreciation of their clinical relevance.

[Contact tracing of paediatric pertussis cases at a tertiary hospital in Barcelona, Spain]. / Estudio de contactos de casos pediátricos de tos ferina en un hospital de tercer nivel de Barcelona.

BACKGROUND AND OBJECTIVES: Pertussis remains an important cause of morbimortality despite current vaccination strategies. This study was designed to describe the results and characteristics of close contacts of pertussis cases diagnosed in children less than 16 years in a tertiary hospital in Barcelona. PATIENTS AND METHODS: Cross-sectional study. Data were collected from chart review of contacts of paediatric cases of pertussis in Vall d'Hebron University Hospital from 2005 to 2009. Only patients with microbiological study done were included. The odds ratio (OR) and 95% confidence interval (95% CI) were calculated as association measure. RESULTS: Ninety-one index cases and 404 contacts were studied. The prevalence of positive cases among contacts was 33.2%. Contacts of index cases younger than 6 months had a higher risk of being positive for pertussis than contacts of older children (OR: 3.38; 95% CI: 1.88-6.10). Primary cases were identified as 16.7% of the contacts studied, who were the source of infection for 67.7% of index cases younger than 6 months and for 26.9% of older index cases. CONCLUSIONS: Contact tracing of paediatric pertussis cases is a necessary clinical activity. It is more likely to find primary cases in the contact investigation of children less than 6 months. Preventive strategies should be targeted primarily to frequent contacts of this age group.