29 research outputs found
Exploring the pathway toward the reduction of paediatric seasonal influenza burden: school-based vaccination and surveillance: School-based influenza vaccination and surveillance
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Breakthrough Infections: A Challenge towards Measles Elimination?
No full textMeasles is one of the most contagious diseases known to man. Despite the existence of a safe and effective live attenuated vaccine, measles can appear in vaccinated individuals. Paradoxically, breakthrough cases increase as vaccination coverage in the general population rises. In measles endemic areas, breakthrough cases represent less than 10% of total infections, while in areas with high vaccination coverage these are over 10% of the total. Two different vaccination failures have been described: primary vaccination failure, which consists in the complete absence of humoral response and occurs in around 5% of vaccinated individuals; and secondary vaccination failure is due to waning immunity or incomplete immunity and occurs in 2–10% of vaccinees. Vaccination failures are generally associated with lower viral loads and milder disease (modified measles) since vaccination limits the risk of complicated disease. Vaccination failure seems to occur between six and twenty-six years after the last vaccine dose administration. This review summarizes the literature about clinical, serological, epidemiological, and molecular characteristics of measles breakthrough cases and their contribution to virus transmission. In view of the measles elimination goal, the assessment of the potential decline in antibody protection and the targeted implementation of catch-up vaccination are essential
A Methodological Approach to Water Concentration to Investigate the Presence of SARS-CoV-2 RNA in Surface Freshwaters
No full textDuring the COVID-19 public health emergency, an increasing number of studies reported the occurrence of SARS-CoV-2 in wastewaters worldwide, but little is known about the presence of the virus in surface freshwaters. The aim of the current study was to develop and validate an appropriate and scalable methodological approach for the concentration and detection of SARS-CoV-2 from surface freshwater samples, collected within the Milan rural network subjected to flood spillways activity. Overall, both surface water and distilled water samples spiked with inactivated SARS-CoV-2 were used to validate the concentration method for pathogens determination. Two pre-filtration systems, filter paper and Sartolab(®) P20 (Sartorius, Germany) and two concentration methods, two-phase (PEG-dextran method) separation and tangential flow ultrafiltration (UF), were compared. The effects of pre-filtration and concentration on viral nucleic acid recovery were assessed through real time RT-PCR targeting SARS-CoV-2 and the internal viral control PMMoV (Pepper Mild Mottle Virus). Our results showed that UF is more sensitive than the PEG-dextran method in viral acid nucleic recovery from surface water samples. Better results were obtained pre-filtering samples with Sartolab(®) P20 and extracting the nucleic acids with undiluted silica, rather than diluted as required by the standard protocol. The proposed method will be used for the monitoring of surface waters in the Milan area
Differential diagnosis on measles and rubella discarded cases highlights a sharp increase in parvovirus B19 infections in Milan, Northern Italy, in the first months of 2024
No full textIn line with European trends, since 2023 Lombardy (Northern Italy) is experiencing a resurgence of measles and an increased number of reported cases of fever and rash. Measles discarded cases observed in our region within the context of measles and rubella surveillance from the first few months of 2024 (N = 30) were investigated for parvovirus B19 (B19V) and other rash-associated viruses. Thirteen cases tested positive for B19V DNA, representing a significant increase from previous years (on average 3 cases per year, p < 0.001) and ~40% of all B19V DNA-positive patients we detected since 2017. In 2024, B19V DNA-positive subjects spanned all ages, and the virus was predominant among adolescents and adults (84.6%). Two B19V infected patients were hospitalised, and likely cross-reacting anti-measles virus IgM were found in both. Our data align with the recent reports from the ECDC and various European countries, which are experiencing a surge in B19V infections, and underline the importance of comprehensive measles and rubella surveillance systems that can adapt to changing epidemiological trends.</p
Detection of human papillomavirus in fresh and dried urine through an automated system for cervical cancer screening in low‐ and middle‐income countries
No full textThe majority of cervical cancer cases and associated deaths occur in low‐ and
middle‐income countries (LMICs), where sociocultural barriers, poor access to
prevention and care, and technical and practical difficulties hinder screening
coverage improvement. Using urine specimens for human papillomaviruses (HPV)
molecular screening through automated testing platforms can help to overcome
these problems. We evaluated the high‐risk (HR) HPV detection performance of
the Xpert ® HPV test on GeneXpert ® System (Cepheid), on fresh and dried urine
(Dried Urine Spot [DUS]) samples as compared to an in‐house polymerase chain
reaction (PCR) genotyping assay. Forty‐five concentrated urine samples collected
from women with known cytological and HPV infection status, determined through
in‐house PCR and genotyping assays, were tested “as is” and as DUS with the Xpert®
HPV test. This system detected HR‐HPV in 86.4% of fresh and in 77.3% of dried
urine samples collected from HPV+ women, correctly identifying HR‐HPV infection
in 100% of women with low‐ and high‐grade lesions. High concordance (91.4%,
k = 0.82) was found between PCR test and Xpert ® HPV Test from urine. Urine‐based
Xpert ® HPV test seems to be a suitable screening test for detection of HR‐HPV
infections associated with low‐ and high‐grade lesions requiring follow‐up
monitoring or treatment. This methodology, relying on noninvasively collected
samples and on available rapid testing platforms, could facilitate large, at‐scale
screening programs, particularly in LMICs and rural areas, thus reducing adverse
outcomes of HPV infection and facilitating achievement of the WHO cervical cancer
elimination goal
A large A(H3N2) influenza outbreak with a high attack rate in a drug user community in Italy, April 2022
No full textDespite the COVID-19 pandemic, influenza remains an important issue. Especially in community settings, influenza outbreaks can be difficult to control and can result in high attack rates. In April 2022, a large A(H3N2) influenza outbreak spread in the largest Italian drug-rehabilitation community. One hundred eighty-four individuals presented influenza-like symptoms (attack rate of 26.2%); 56% previously received the influenza vaccine. Sequence analyses highlighted a genetic drift from the vaccine strain, which may have caused the observed lack of protection
Letter to the editor: Further identification of a measles variant displaying mutations impacting molecular diagnostics, Northern Italy, 2024
No full textTo the editor: We read with great interest the article by
Pérez-Rodríguez et al. [1], reporting the circulation of
measles virus (MeV) variants (genotype D8) displaying three mutations impacting molecular diagnostics.
The mutations occurred in the 450nt-long C-terminal
(N-450) region of the nucleoprotein (N) gene that is
usually the target of real-time reverse-transcription
(RT)-PCR assays commonly employed by surveillance
laboratories. In detail, the three T-to-C synonymous
substitutions were located within the annealing site
of the reverse primer recommended by the United
States Centers for Diseases Control and Prevention
(CDC, Atlanta) [2]. This results in a slight loss of test
sensitivity
COVID-19 monitoring of school personnel through molecular salivary test and dried blood spot analysis
No full textBackground: When the coronavirus disease 2019 (COVID-19) pandemic broke out, most countries enforced school closures as a precautionary measure. Although COVID-19 is still present three years later, schools have been reopened. We aimed to test the association of molecular salivary testing (MST) and dried blood spot (DBS) analysis for community surveillance by investigating the immunological profile of a group of school staff during and following COVID-19 vaccination. Methods: We conducted the study in a school in Milan from April 2021, when school staff were administered the first dose of vaccine against SARS-CoV-2, until the school year ended in June 2022. Each participant provided samples for MST and DBS one month (T1, W1) after receiving their first dose of vaccine. Subsequently, they collected weekly MST samples for five weeks (W2-W6), plus a DBS sample in the last week (T2). Both samples were collected one (T3), four (T4), and seven months (T5) after the administration of the second vaccine dose in May 2021. A final DBS sample was collected one year (T6) after T3. Results: Sixty participants provided 327 MSTs and 251 DBSs. None of the MST samples tested positive for SARS-CoV-2 RNA during the study period. A total of 201 DBS samples tested positive for the IgG semiquantitative analysis. Negative samples were found only at T1 (20.45%) and T2 (7.32%). We observed borderline results at T1 (4.55%), T2 (7.32%), and T4 (2.70%). The anti-SARS-CoV-2 average antibody ratio increased after the second dose between T2 and T3, and the trend peaked after the third dose between T4 and T6. We performed an immunoenzymatic assay of antibodies against nucleocapsid protein on samples collected at T1 from five participants who reported having been infected before the study and from four subjects with an abnormal increase in the antibody values at T4. Two samples tested positive in the first group and two in the second one. Conclusions: Our findings show that MST and DBS could be effective tools in the active surveillance of school personnel and that schools could be considered safe settings in view of SARS-CoV-2 infection. Vaccines might have contributed to case and/or symptom reduction
Serological investigation of SARS-CoV-2 infection in patients with suspect measles, 2017-2022
No full textBackground: Several studies suggested that SARS-CoV-2 was already spreading worldwide during the last months of 2019 before the first outbreak was detected in Wuhan, China. Lombardy (Northern Italy) was the first European region with sustained SARS-CoV-2 transmission and recent investigations detected SARS-CoV-2-RNA-positive patients in Lombardy since late 2019. Methods: We tested for anti-SARS-CoV-2 IgG all serum samples available in our laboratory (N = 235, collected between March 2017 and March 2022) that we received within the framework of measles/rubella surveillance from measles and rubella virus-negative patients. Results: Thirteen of 235 samples (5.5%) were IgG-positive. The positivity rate increased starting in 2019 and was significantly different from the expected false positive rate from 2019 onwards. Additionally, in 2019 the percentage of IgG-positive patients was significantly lower among SARS-CoV-2 RNA-negative patients (3/92) compared to SARS-CoV-2 RNA-positive patients (2/7, p = 0.04). The highest percentage of IgG positivity in the pre-pandemic period was recorded during the second half of 2019. This coincided with an increase in negativity for measles and a widening of the peak of the number of measles discarded cases per 100,000 inhabitants, indicating a higher-than-normal number of measles-negative patients experiencing fever and rash. This also coincided with the first patient positive for SARS-CoV-2 RNA (September 12th, 2019); this patient was also positive for anti-SARS-CoV-2 IgG and IgM. Conclusions: Although the number of samples was low and one cannot conclusively establish that the virus started circulating in Lombardy around September 2019, our findings should stimulate similar research investigating the possibility of undetected SARS-CoV-2 pre-pandemic circulation
Differential diagnosis of fever and rash cases negative for measles and rubella to complement surveillance activities
No full textIn the quest to eliminate measles virus (MV) and rubella virus (Ruv), every suspected case must be properly identified and diagnosed. Since 2017, in Milan (Italy), a total of 978 measles and rubella suspected cases (fever and rash) were investigated and 310 were not laboratory confirmed (discarded cases). To improve surveillance activities, we investigated the presence in discarded cases of 8 other viral pathogens
commonly associated with rash: human herpesvirus 6 (HHV‐6) and 7 (HHV‐7), parvovirus B19 (B19V), enterovirus (EV), Epstein−Barr virus (EBV), human adenovirus (HAdV), cytomegalovirus (HCMV), and SARS‐CoV‐2. Differential diagnosis was carried out on 289 discarded cases by multiplex real‐time PCR assays. At least one pathogen was detected in 188 cases (65.1%) with HHV‐7 being the most frequently detected virus. No difference in the number of detected infections overtime was observed and infections were identified in all age groups. As expected, most HHV‐6, EV, HAdV, and HCMV‐positive cases were found in children aged 0−4 years and HHV‐7 was most frequent in the 15−39 age group. In light of the World Health Organization measles elimination goal, the introduction of laboratory methods for
differential diagnosis is required for the final classification of clinically compatible cases. The used screening panel allowed us to increase the percentage of virus‐positive cases to 87.5%, allowing us to clarify viral involvement and epidemiology, improve diagnosis, and strengthen surveillance activities. As all investigated pathogens were detected, this diagnostic panel was a suitable tool to complement MV and RuV surveillance activities
