M L Ciofi Degli Atti

Immunization coverage and timeliness of vaccination in Italian children with chronic diseases

Since children with chronic diseases represent a primary target for immunization strategies, it is important that their immunization coverage and timeliness of vaccines is optimal. We performed a study to measure immunization coverage and timeliness of vaccines in children with type 1 diabetes, HIV infection, Down syndrome, cystic fibrosis, and neurological diseases. A total of 275 children aged 6 months-18 years were included in the study. Coverage for diphtheria-tetanus-pertussis (DTP), polio (Pol), and hepatitis B (HBV) vaccines approximated 85% at 24 months, while measles-mumps-rubella (MMR) coverage was 62%. Immunization coverage for seasonal influenza was 59%. The analysis of timeliness revealed that there was heterogeneity among children with different chronic diseases. A proportional hazard model showed that children with HIV infection had the longest time to complete three doses of DTP, Pol, and HBV, and those with neurological diseases received the first dose of MMR later than the other categories. Causes of missing or delayed vaccination mostly included a concurrent acute disease. Children with chronic diseases should be strictly monitored for routine and recommended vaccinations, and health care providers and families should be properly informed to avoid false contraindications.

Assessment of varicella underreporting in Italy

We conducted a study to assess the degree of varicella underreporting in Italy, and its distribution by age group and geographical area. Underreporting in individuals from 6 months to 20 years of age was computed as the ratio between the varicella seroprevalence in 1996 and the 1996 lifetime cumulative incidence based on statutory notifications. The degree of underreporting at the national level was 7.7 (95% CI 7.4-7.9); underreporting was greater in older age groups and in southern Italy. Quantification of underreporting can contribute to better understanding of the burden of varicella and to evaluating the potential impact of mass vaccination.

Rubella seroprofile of the Italian population: an 8-year comparison

The objective of this study is to evaluate how increasing MMR infant vaccination coverage in recent years has modified the epidemiology of rubella in Italy. A cross-sectional population-based seroprevalence study of rubella antibodies was conducted on 3094 sera, in 2004, and results were compared with data obtained by the same method in 1996. The overall proportion of rubella-seropositive individuals was found to be significantly higher in 2004 with respect to 1996 (84.6% vs. 77.4%). However, an increase in seropositivity was observed only in the 1-19 years age groups. Recent increases in childhood MMR vaccination coverage, therefore, have not had an impact on seroprevalence in women of childbearing age, over 5% of whom remain susceptible to rubella. Preconception screening and postpartum vaccination of susceptible women are fundamental if the WHO target of less than one case of congenital rubella syndrome per 100,000 live births is to be attained.

Rubella control in Italy

In Italy, rubella vaccination has been recommended since 1972 for pre-adolescent girls, and since the early 1990s for all children in the second year of life. Nevertheless, coverage in children from 12 to 24 months of age is suboptimal (i.e., 56% in 1998, 78% in 2003), with wide variations among regions. As a result, rubella is still circulating in Italy, and in 1996 the percentage of women susceptible to rubella between 15 and 39 years of age was >5%. Congenital rubella syndrome (CRS) was a notifiable disease between 1987 and 1991, with a range of 8-76 cases reported annually. Since 1992, national incidence data are no longer available, but local reports show that CRS cases are still occurring. Nationwide, coordinated and uniform actions are needed to control CRS effectively. For this reason, the National Plan for the Elimination of Measles and of Congenital Rubella has recently been launched. This plan includes strategies aimed at increasing MMR vaccination coverage in children and specific control measures for congenital rubella control, i.e., improving the vaccination of susceptible women of childbearing age, and reintroducing national surveillance of CRS.

Reactogenicity and immunogenicity of adult versus paediatric diphtheria and tetanus booster dose at 6 years of age

We evaluated the reactogenicity and immunogenicity of a booster dose of diphtheria-tetanus vaccine administered at the age of school-entry, comparing a low-dose vaccine (dT) to the standard paediatric dose (DT). Participants were randomly assigned to receive one of the two vaccines; the study was evaluator-blinded. The frequency of side-reactions was similar when comparing the two groups, except when considering local redness and swelling, which were significantly more frequent among the DT group. The post-booster geometric mean titre of diphtheria antibodies in the DT group was twice as high as that in the dT group (14.1 IU/ml versus 7.7 IU/ml; P<0.001). The higher antibody response and the comparable reactogenicity indicate that DT should be used as booster at school-entry, particularly if additional booster doses during adolescence or adulthood are not administered.

Scenarios of diffusion and control of an influenza pandemic in Italy

To predict the spread of a pandemic strain of influenza virus in Italy and the impact of control measures, we developed a susceptible-exposed, but not yet infectious-infectious-recovered, and no longer susceptible (SEIR) deterministic model with a stochastic simulation component. We modelled the impact of control measures such as vaccination, antiviral prophylaxis and social distancing measures. In the absence of control measures, the epidemic peak would be reached about 4 months after the importation of the first cases in Italy, and the epidemic would last about 7 months. When combined, the control measures would reduce the cumulative attack rate to about 4.2%, at best, although this would require an extremely high number of treated individuals. In accordance with international findings, our results highlight the need to respond to a pandemic with a combination of control measures.

Measles elimination in Italy: projected impact of the National Elimination Plan

A mathematical model was used to evaluate the impact of the Italian Measles National Elimination Plan (NEP), and possible sources of failure in achieving its targets. The model considered two different estimates of force of infection, and the possible effect on measles transmission of the current Italian demographic situation, characterized by a below-replacement fertility. Results suggest that reaching all NEP targets will allow measles elimination to be achieved. In addition, the model suggests that achieving elimination by reaching a 95 % first-dose coverage appears unlikely; and that conducting catch-up activities, reaching high vaccination coverage, could interrupt virus circulation, but could not prevent the infection re-emerging before 2020. Also, the introduction of the second dose of measles vaccine seems necessary for achieving and maintaining elimination. Furthermore, current Italian demography appears to be favourable for reaching elimination.

The epidemiology of mumps in Italy

In Italy, although vaccination has been recommended for a number of years, vaccination coverage for mumps is still sub-optimal. The objective of the present study was to evaluate the seroprevalence of mumps antibodies in the Italian population, stratified by age, gender and geographical area. The proportion of individuals positive for mumps antibodies remained stable in the age classes 0-11 months and 1 year (25.4% and 30.8%, respectively) and showed a continuous increase after the second year of life. The percentage of susceptible individuals was higher than 20% in persons 2-14 years of age and exceeded 10% in persons 15-39 years of age. No statistically significant differences were observed by gender or geographical area. Comparison between these results and the data obtained from a 1996 survey showed a statistically significant increase in seroprevalence in the age class 2-4 years. No changes were observed in the other age-groups. The results of this study confirm that the efforts made in recent years to improve vaccination coverage within the second year of life should be strengthened.

Haemophilus influenzae Invasive Disease in Italy, 1997–1998

The following members comprise the Haemophilus influenzae Study Group: Istituto Superiore di Sanità, Laboratorio di Epidemiologia e Biostatistica: P. Carbonari; Associazione Microbiologi Clinici Italiani (AMCLI): P. Nicoletti, A. Goglio; Regione Piemonte: A. Ruggenini Moiraghi, S. Orecchia, A. Castella, C. Zotti; Provincia Autonoma di Trento: V. Carraro, I. Caola, A. Calì; Regione Liguria: P. Crovari, C. Giordano, P. Tixi, M. Lemmi; Regione Toscana: P. Bonanni, A. Tomei, P. Pecile, E. Balocchini, L. Pecori; Regione Campania: F. Santonastasi, L. Cafaro, V. Pagano; Regione Puglia: S. Barbuti, M. Chironna Haemophilus influenzae Invasive Disease in Italy, 1997–1998

Corrigendum to “Reactogenicity and immunogenicity of adult versus paediatric diptheria and tetanus booster dose at 6 years of age” [Vaccine 20 (2002) 74–79]☆

Corrigendum Corrigendum to “Reactogenicity and immunogenicity of adult versus paediatric diptheria and tetanus booster dose at 6 years of age” [Vaccine 20 (2002) 74–79] M.L. Ciofi degli Atti a,∗, S. Salmaso a, B. Cotter a,d, G. Gallo c, G. Alfarone b, A. Pinto b, A. Bella a, C. von Hunolstein b a Laboratory of Epidemiology and Biostatistics, Istituto Superiore di Sanita, Reparto Malattie Infettive, Viale Regina Elena 299, 00161 Roma, Italy b Laboratory of Bacteriology and Medical Mycology, Istituto Superiore di Sanita, Viale Regina Elena 299, 00161 Roma, Italy c Regional Health Authority, Veneto Region, Venezia, Italy d European Programme for Intervention Epidemiology Training (EPIET), Roma, Italy