Implementation of Acute Flaccid Paralysis Surveillance in Emilia-Romagna, Italy: 2018-2019 analysis

Problem

Acute flaccid paralysis (AFP) active surveillance is the gold standard in polio eradication process. Italy was classified in 2017 at intermediate risk of poliovirus reintroduction based on suboptimal poliovirus surveillance. The aim of this study was to restore an adequate level of AFP surveillance in Emilia-Romagna Region.

Description of the Problem

The Emilia-Romagna's Reference Centre for AFP surveillance, in collaboration with the regional Public Health Service identified a collaborative network for AFP Surveillance by analysing the 2015-2017 Hospital Discharge Registers in all region's hospitals. The surveillance protocol was reviewed with the development of a computerized system of Active Surveillance-Zero Reporting sent by e-mail to doctors in the network every 15 days since October 2018. The goal was to restore the AFP notification system to meet WHO requirements sensitivity, completeness of case investigation, completeness of follow-up and to monitor the active surveillance program adherence.

Results

The active surveillance network was composed by 49 doctors from both hospital administrations and clinical wards from 4 University Hospitals and 7 Local Health Authorities throughout the region. By the end of 2019, the mean response to each e-mail was 48.5% (SD 7.5%); 7 AFP cases have been reported; 85.7% received a full clinical and virological investigation and 83.3% completed the 60 day's follow-up. The final diagnosis of the cases was: 3 Guillain-Barre, 1 transient polyneuritis after HAV vaccination, 1 neuromyopathy from chronic disease, 1 acute myelitis in patient with DADA2. In 2 cases the paralysis persisted after 60 days.

Lessons

In 2019, the active surveillance system reached sensitivity, completeness of case investigation and follow-up required. Intervention had no expenses, is easily reproducible, created a direct collaboration between clinical colleagues in the network and the reference center which restored adherence to AFP surveillance.

Key messages

This work proposes how to improve AFP surveillance in a setting with low polio risk perception due to the absence of cases. Additionally, it reinforces the importance of direct collaboration/teamwork between institutions, regional reference centres and clinicians.

Genetic analysis of human and swine influenza A viruses isolated in Northern Italy during 2010-2015

Influenza A virus (IAV) infection in swine plays an important role in the ecology of influenza viruses. The emergence of new IAVs comes through different mechanisms, with the genetic reassortment of genes between influenza viruses, also originating from different species, being common. We performed a genetic analysis on 179 IAV isolates from humans (n. 75) and pigs (n. 104) collected in Northern Italy between 2010 and 2015, to monitor the genetic exchange between human and swine IAVs. No cases of human infection with swine strains were noticed, but direct infections of swine with H1N1pdm09 strains were detected. Moreover, we pointed out a continuous circulation of H1N1pdm09 strains in swine populations evidenced by the introduction of internal genes of this subtype. These events contribute to generating new viral variants-possibly endowed with pandemic potential-and emphasize the importance of continuous surveillance at both animal and human level.

Immunity status against poliomyelitis in childbearing women in a province of northern Italy. A cross-sectional analysis

This cross-sectional seroprevalence study was carried out in 2007 to estimate the immunological status associated with poliomyelitis among fertile women , according to demographic changes. We consecutively enrolled 493 healthy mothers at the time of delivery in order to assess immunity against poliomyelitis by a neutralisation inhibition test. Despite the lack of seronegative subjects, our investigation showed low GMTs, which confirmed a reduction in the "booster effect". The GMTs against poliovirus 1, poliovirus 2 and poliovirus 3 were 25.20, 14.79 and 8.80, respectively. The data that emerged from our survey showed that GMTs have decreased significantly since 1983 and reached low-to-medium values over the past 25 years. The serum prevalence studies, together with the vaccination coverage estimates, are useful and are strongly recommended in order to highlight and identify the possible scenarios in which susceptible subject groups may be present simultaneously as well the possibility of the reintroduction of wild virus in an area that was previously free of polio.

Detection of enteroviruses from urban sewage in Parma

BACKGROUND AND AIM OF THE WORK

The human enteroviruses (EV) are the most common and widespread human viruses in the world. They have bowel as their natural habitat and they can spread in the environment through the faecal excretion. In the continental climate Regions these viruses may cause epidemic outbreaks in summer and fall, while in the tropical Regions the EV infections present a high incidence during all year. The symptoms can be minor or subclinic, but they can be also associated to rare and serious diseases. The aim of this study was to evaluate the environmental circulation of polioviruses and non-polio enteroviruses (NPEV) using standard methods of urban wastewater surveillance recommended by the WHO.

METHODS

A total of 188 wastewater samples were collected between February 2005 and December 2008 from two sewage treatment plants in Parma. The sampling was carried out twice a month. Environmental variables were collected for each day of sampling.

RESULTS

Out of the 188 examined wastewater samples, 78.7% were positive to the enterovirus research. One out of the 148 positive samples was identified as poliovirus Sabin-like type 3. The remaining 147 positive samples were enteroviruses non polio: Coxsakieviruses and Echoviruses. All Coxsakieviruses isolated were of type B.

CONCLUSIONS

The proposed method has shown high sensibility, also in presence of very low expected prevalence of vaccine poliovirus. It allows to verify the kind and relative frequency of enteric viruses circulating in the country, whose characteristics (virulence and pathogenicity) may vary with reference to a different epidemiologic and demographic structure of the resident population.

Mother to child transmission of hepatitis C virus in a province of northern Italy

INTRODUCTION

Study reports of mother to child transmission of hepatitis C virus (HCV) have shown transmission rates ranging from 3 to 37%, according to maternal viremia and HIV-1 coinfection. The present study evaluated the prevalence of the HCV infection in the general population and the incidence of vertical transmission, from women who delivered in the Obstetric Clinic of the Hospital of Parma from January 1st 1996 to 31st 2001 December.

METHODS

Mothers and children were tested for the presence of HCV-RNA within one week after delivery. Children were considered to be infected when they were found positive at least twice for viral RNA or antibodies were still detectable at the end of the follow-up period (18 months) in blood.

RESULTS

Out of 13,025 women, 110 (0.8%) were found positive for anti-HCV antibodies; 72 of them (65.4%) were HCV-RNA positive. All 110 children were positive for anti-HCV antibodies in the first blood sample (time 0); 8 of them were HCV-RNA positive. Three children were still viremic at the end of the follow-up whereas 5 showed a clearance. No significant differences were found between viremic and nonviremic children with respect to gestational week, maternal alanine aminotransferase (ALT) levels and newborns weight at birth.

CONCLUSION

This investigation shows that vertical transmission may occur in a general obstetric population despite a low prevalence of HCV-positive subjects.

[Evaluation of the immune status against poliomyelitis in a group of young immigrants]

The immunity state towards poliomyelitis has been evaluated in 506 young immigrants coming from European and extraeuropean countries without immunization history. Polioviruses 1, 2 and 3 antibodies were detected in 97% of the serum samples. 15 subjects did not have detectable antibodies at 1:2 dilution for one or two polioviruses. Out of these subjects, 6 (coming mostly from East European Region) were negative in the undiluted serum too. On the whole, GMTs for type 1 (43,29) and 2 (41,9) appeared higher than those for type 3 (33,6). Moreover there are differences among the origin countries; in fact, GMTs more elevated for type 1 and 3 (74,6 and 49,6 respectively) have been observed in the subjects coming from the African region, as well in those coming from the American region.

Somatosensory extinction for meaningful objects in a patient with right hemispheric stroke

Implicit, high level processing of extinguished objects has often been described in the visual modality. In the tactile domain, however, research on this topic is meagre and it is still uncertain whether processing of tactually presented stimuli can be affected by the same attentional disorders as visual stimuli. In this paper we describe a patient, ENM, with visual neglect and light touch extinction who, in a naming task of objects presented in the tactile modality, simultaneously to both hands, showed extinction for left hand objects. He was, nevertheless, able to make above chance Same/Different judgements on the two stimuli. We also tested two neurologically intact subjects who performed the test wearing a ski-glove on the left hand to impair the recognition of left hand objects. In these subjects, Same/Different judgements were at chance level when recognition rate was as low as that found in patient ENM. This happened when either the objects, although sharing the same name were different in shape (conditions Same-Different) or when the two objects were different with respect to the category name but were actually physically similar (conditions Different-Similar). However, when the objects were either identical or completely different, i.e., in a condition where judgement could be based simply on the physical analysis of the object shape (condition Same Identical and Different Dissimilar), their Same/Different judgements were above chance, despite the tactual deficit. Our conclusion was that patient ENM showed implicit recognition of left hand objects, at least in the Same Different and in the Different-Similar conditions, whereas, in the same conditions, normal subjects with an artificial sensory impairment did not. Our results also show that Same/Different judgements may be, in some conditions, less demanding than naming tasks, as suggested by Farah et al. Furthermore, patient ENM performed the test both with uncrossed and crossed hands. We found that extinction always affected the hand contralateral to the brain damage, although there was a tendency for a decrement of the ipsilesional hand performance in the crossed condition. We discuss these findings with reference to the most recent theories on the existence of a body centered spatial frame of reference.

Antipoliomyelitis neutralizing antibodies in maternal and neonatal serum

During 1993 blood samples were taken from 1251 women consecutively admitted to the Maternity Ward of the University of Parma. Samples were also taken from all the newborn babies. Absence of antipolio neutralizing antibodies in serum diluted 1/2 was shown in 6 mothers; 4 mothers for polio 1, 1 mother for polio 2 and 1 simultaneously for the poliovirus 1 and 3. If one considers only the cases of absence in undiluted serum, there were 2 negative subjects (0.16%). One of these was for antibodies against polio 1 and the other for antibodies against polio 2. In the cord blood samples the frequency of negative results in serum diluted 1/2 is higher: 42 in all with 13 babies negative for polio 1. 17 babies for polio 2, 8 for polio 3 and 2 babies simultaneously for polio 1 and polio 3. If one considers just the babies without antibodies even in undiluted serum, the fraction of seronegatives is 9 (0.7%) with 1 for polio 1, 6 for polio 2 and 1 for types 1 and 3. The Geometric Mean Titres of the antibodies are significantly higher in mothers born before 1964 (year of introduction of mass vaccination with OPV) compared with those born after that year. Likewise, the same phenomenon was observed in the respective children.

Antipoliomyelitis immunity status among a population that was regularly vaccinated 11-12 years before

A study of poliomyelitis neutralizing antibodies was carried out on 165 samples of blood serum drawn from subjects aged 14-15 years who had completed vaccination with OPV 11 or 12 years ago. Two different methods of incubation of the serum-virus mixtures (1 hour at 37 degrees C; 6 hours at 37 degrees C and then 18 hours at 4 degrees C, respectively) and two different cell lines (RC-37 and Hep-2) for the inoculation of these mixtures were employed. The results were also evaluated in relation to different initial dilutions of the sera (from 1:4 to 1:1). With the 1:4 initial serum dilution the highest frequencies of sero-negativity were observed utilizing the short incubation time and inoculation in Hep-2 (42% for polio 1, 10% for polio 2, 32% for polio 3). These frequencies diminish significantly utilizing the RC-37 cell line and the long incubation respectively. Under all the experimental conditions the results were better when the 1:2 initial serum dilutions were employed and even better when undiluted sera were used. Neutralizing antibodies against the 3 types of poliovirus were detected in the undiluted sera of all the subjects utilizing the long incubation and inoculation in either the RC-37 or the Hep-2 cell lines. In three subjects lacking detectable antibodies at the 1:4 dilution of the sera, the administration of a dose of IPV produced after 5-7 days a high response which remained almost unchanged 30 days later.