Vaccination Status and Prevalence of Enteric Viruses in Internationally Adopted Children. the Case of Parma, Italy
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09-veronesi:09-veronesi 28-02-2012 11:46 Pagina 208 ACTA BIOMED 2011; 82: 208-213 © Mattioli 1885 O RIGINALARTICLE Vaccination status and prevalence of enteric viruses in internationally adopted children. The case of Parma, Italy Licia Veronesi1, Raffaele Virdis2, Sabrina Bizzoco1, Maria Eugenia Colucci1, Paola Affanni1, Francesca Paganuzzi1, Matteo Riccò1, Emanuela Capobianco1, Maria Luisa Tanzi1 1 Department of Public Health, Parma Medical School, University of Parma, Italy; 2 Department of Pediatrics, Parma Medical School, University of Parma, Italy Abstract. On age basis, internationally adopted children may have begun or fully completed all required vac- cinations, but official documentation from original Countries is frequently insufficient. Aims of this study were to evaluate the seroprotection rate for tuberculosis, hepatitis B, poliomyelitis and tetanus according to immunization cards in 67 children recently adopted and to test the prevalence of enterovirus on faecal spec- imens. Seroprotection and vaccination status were frequently inconsistent and these results confirm that im- munitary surveillance is a cornerstone for the prevention of diseases for which a vaccination is available. (www.actabiomedica.it) Key words: internationally adopted children; immune protection; enteric viruses prevalence Introduction Decree n. 492 of December 1st 1999), whose reports eventually encompass all international adoptions ad- Internationally adoption in Italy mitted to Italy between November 2000 and Decem- ber 2007. Every year, North America and several European NCIA report describes 2007 as the year with the countries receive a migratory flow of adopted children highest entry flow ever (3,420 children); despite rank- from East-Europe, South-America, Asia and Africa. ing 9th among countries with high adoption rate, Italy International adopted children are a multi-ethnic is presently the only country recording a still growing and multi-cultural ensemble that is rapidly evolving adoption flow. More precisely, Italian adoption flow due to the growing number of involved countries. By grew by 10% between 2005 and 2006, and by 7.3% 2005, the slow accreditation procedures in Russian during the following year. Moreover, the number of Federation and Ukraine and the empowerment of new adopted children per couple showed a similar grow- laws in Belarus (2004) were associated with a growing ing trend, reaching the peak of 1.27 during 2007 and number of Asian origin adoptions in Italy . Between becoming as very close to the national ratio of natural 2004 and 2007, homeland countries of international child per woman (presently ranging between 1.03 in adoptees grew up from 58 to 76 and included Arme- Sardinia and 1.54 in Trentino Alto-Adige). Emilia nia, Kazakistan, Latvia, Lebanon, Mali, Mauritius, Romagna records 1.32 biological children per couple Central African Republic, Dominican Republic, and 1.19 requests of international adoption per cou- Senegal and Uruguay, Kyrgyzstan, Tanzania and ple. Bosnia-Herzegovina. By 1999, International Adop- Overall, 58% of children admitted to Italy are tion flows are monitored by the National Commission males, the mean age being 5.2 years. The age appears for International Adoptions (NCIA) (Presidential to be strongly correlated with the country of origin: 09-veronesi:09-veronesi 28-02-2012 11:46 Pagina 209 Immunitary status in Internationally adopted children 209 younger children (≤ 4 years) are more frequently from Materials and Methods Asia (35% of Asian International Adoptees is less than 1 year old, and 39.9% less than 4 years old), Between March 2004 and September 2007, 67 whereas older children (> 4 years) are typically of children adopted by families residing in Parma and South American and East European countries (1). counties nearby were evaluated by the “Center for Thus, in Italian regions with high presence of Asian First Sanitary Evaluation of International Adoptions”. adoptees, the average newly adopted children age is Admission protocol required an accurate evaluation of lower (mean adoption age: 3.72 years for Piemonte, physiological and pathological conditions of the 3.87 for Val d’Aosta, 4.05 for Trentino Alto Adige). Adoptee, achieved through a deep physical examina- tion and by laboratory tests. Adopted Children and Immunity Sanitary history and full information about previ- ously undergone vaccinations of every child was re- Nearly all children coming to Italy as adopted or trieved. Tubercular sensitivity were also established. following their immigrant families come from coun- Unsatisfactory nutritional status, original living envi- tries where life conditions and poor healthcare systems ronment (family or institutes), time spent in Italy be- might impair their health status. Moreover, their in- fore first medical evaluation were also retrieved for teraction with welcoming population could potential- every child. ly constitute a risk (2-4). Accurate and scrupulous Faecal specimens were collected in order for en- clinical evaluations are therefore mandatory, aiming to teric viruses and polioviruses determination, and an early diagnosis of nutritional deficiency or infec- blood samples were collected in order to evaluate im- tious diseases (5), and obviously requiring immediate mune status for the three polioviruses, tetanus and he- identification of performed vaccinations. patitis B. On age basis, adoptees may have begun or fully For poliovirus identification, fecal specimens completed all required vaccinations, although with were treated with chloroform (in order to remove bac- some scheduling difference (6), but official documen- teria, fungi and cytotoxic lipids) centrifuged and sup- tation from original Countries is frequently scarce, or plemented with antibiotics. The supernatant was re- insufficient (7). As an example, the survey performed covered and stored at -20°C. Three cellular lines were by Schulpen et al. (8) on adopted children from applied in order to isolate cytopathogenic viruses: Africa, Asia, South America and Easter Europe (13 Hep2, RD and L20B. Isolate characterization was countries overall) identified the 30% of Chinese-ori- performed through infectivity neutralization reaction gin children as incompletely vaccinated against po- with standard sera (WHO methodics (10)). Every liomyelitis, diphtheria and tetanus, despite their vacci- specimen was double-checked by means of RT-PCR, nation schedule was recorded as fully completed. with Enterovirus-specific primers (11). In order to protect the child and his adoptive Infectivity-neutralizing antibodies were identi- family, immunitary status of adopted children should fied for the three polioviruses through a long incuba- be regularly evaluated, providing all vaccinations re- tion neutralization assay (12). The antibody titer of quired by our health regulation when otherwise neces- the three polioviruses was defined as the reciprocal sary (9). The public health approach to this problem value of the highest serum dilution showing a com- should consider all adopted children as actually “not- plete neutralization of the cytopathic effect. Antibody vaccinated”, thus providing all requested vaccinations titers lower than 1:2 were defined as seronegative to each single adopted child or, more appropriately, whereas levels equal or higher than 1:8 as protective. vaccinating only those with a serologically confirmed Anti-tetanus antibody determination was performed “no-vaccination status”. by means of an ELISA kit (RIDASCREEN® Kit Aim of this study is then to evaluate health and Tetanus IgG, Biopharm®), considering titers ≤ 0.1 particularly vaccination status in international adopt- UI/ml as negative, average protection between 0.11 ed children. UI/ml and 0.9 UI/ml, and strongly protective ≥ 1 UI/ml. 09-veronesi:09-veronesi 28-02-2012 11:46 Pagina 210 210 L. Veronesi, R. Virdis, S. Bizzoco, et al. Immune-enzymatic methods with particles cap- teroviruses (Coxsackievirus) and 14% were aden- ture (MEIA) were applied in order to perform He- oviruses. Mean age was significantly lower in positive patitis B evalutation (AUSAB – Abbot AXSYM than in negative children (3.3 years; CI95% 2.6-4.1 vs SYSTEM®). Anti-HBc antibodies were evaluated 5.5 years; CI95% 4.1-7.0). Furthermore, residence in through CORAB® Kit (Abbott). Italy of positive children appeared as significantly longer (10.2 weeks; CI95% 6.8-13.5 vs 6.2 weeks; CI95% Statistical analysis 4.5-7.9; p = 0.043). Continuous variables were summarized as mean, Immunization records and vaccine serology standard deviation (SD) and range of values. Catego- rial variables were represented in frequency tables. For In figure 1, vaccination status of adopted chil- poliomyelitis, data were stratified for sex, age (1-2 dren is reported. An official certificate of performed years old, 3-5 years old, ≥ 6 years old), likely vaccina- tuberculosis vaccination was available for 31 of 67 tion schedules and WHO region of origin. Differ- children (46.3%). However, Mantoux test, performed ences in geometrical mean titers (GMTs) were evalu- at the first medical evaluation on 43 children, was ated through Analysis of Variance (F test and Stu- positive in 4 vaccinated children (12.9%) and in 4 dent’s t test) on regional origin basis, nutritional sta- children lacking sanitary documentation (11.1%). A tus, sex, age class. P value < 0.05 was considered sta- vaccination for MMR was certified in 30 children tistically significant. All statistical analyses were per- (44.8%), whereas 50 (74.6%) resulted previously