Genotype D4 Research Articles

Surveillance and genetic characteristics of imported cases of measles virus of D8 genotype in Hebei province

Objective: To understand the epidemiological and genotypic characteristics of imported cases of measles virus of D8 genotype in Hebei province. Methods: Epidemiological investigation of measles cases in surveillance was carried out. The throat swabs of the measles cases in acute phase were collected for real time RT-PCR identification, measles virus culture and genotype identification. Results: A total of 36 imported measles cases of genotype D8 were detected. The cases were mainly distributed in 8 counties of Handan city. Number of confirmed measles cases in Cheng'an county was the highest, accounting for 58.33% (21/36) of all the reported cases. All patients had fever and rash, and 55.55% (20/36) of the cases were under 2 years old and 86.11% (31/36) of the cases had no immunization history. The children with pneumonia accounted for 44.12% (15/34) of the total children with D8 genotype measles virus infection. The nucleotide and amino acid homologies between the imported measles virus genotype D8 and the WHO reference strain of D8 genotype (D8-Manchester.UNK/30.94) were 98.4%-98.6% and 97.3%, respectively. Compared with the strains of H1 genotype in China, the nucleotide and amino acid homologies were 92.8%-93.1% and 93.3%, respectively. Conclusions: The imported cases of measles virus of D8 genotype might have caused local transmission in Hebei province. Molecular epidemiological surveillance for measles virus needs to be further strengthened. It is necessary to detect and control the epidemic early and improve the coverage rate and timely rate of measles vaccination. It is also important to prevent cross infection in hospitals.

Epidemiological and molecular characteristics of a measles outbreak in northern Vietnam, 2013-2014.

A nationwide measles outbreak occurred in Vietnam between 2013 and 2014. To provide an overview on the 2013-2014 measles outbreak in northern Vietnam using epidemiological and molecular analysis of the measles virus (MeV). Epidemiological information was collected from all suspected cases of measles/rubella. Serum and/or throat swabs were collected for laboratory confirmation of measles. MeV genomes were detected and sequenced for phylogenetic analysis. A total of 9577 confirmed measles cases were reported in northern Vietnam with an incidence rate of 116.4/1,000,000 population. Of these, approximately 76.3% had unvaccinated or unknown vaccination history and 55.7% were under five years old. The outbreak started in a minority population from the mountainous area bordering Lao PDR and China and exploded in high-density population areas. Molecular analysis of MeV revealed co-circulation of genotypes H1 and D8, with H1 as the predominant strain, and divided into two clusters: cluster 1, sharing high similarity with those detected in China and Lao PDR, and cluster 2, circulating locally with unidentified origin. The minor D8 strains belonged to the D8-Frankfurt cluster. The outbreak originated in and spread from a population with limited access to vaccines. Molecular analysis revealed co-circulation of MeVs with three different origins during the outbreak. This is the first report to provide an overview of the 2013-2014 measles outbreak in northern Vietnam, demonstrating the need for vaccination strategies against measles that are tailored to local conditions with enhanced molecular surveillance to achieve measles elimination.

An efficient molecular approach to distinguish chains of measles virus transmission in the elimination phase.

Measles viruses continue to spread globally, despite the availability of a safe and effective vaccine. Molecular surveillance of measles virus has become an essential tool to demonstrate whether cascades of infections in a certain region or country are the result of endemic spread or the repeatedly introduction of the virus in contained outbreaks. Currently, molecular surveillance of measles viruses worldwide is mainly based on 450 nucleotides of the C-terminal region of the nucleoprotein (N450). However, as a result of the disappearance of particular measles virus clades over the past decades, this gene segment does not provide sufficient resolution anymore to answer these questions. To increase the molecular resolution, sequence data were collected from three regions of the measles virus genome, the partial non-coding region between the M and F gene (M-F NCR4465-4754), partial H gene (H8022-8621) and the partial L gene (L10724-11438) for measles viruses detected in 2018 and 2019 in the Netherlands. Analysis of obtained sequence data indicated that sequencing of these three regions resulted in an increase in molecular resolution for measles virus genotype B3 and D8 viruses, two of the four global genotypes currently predominant in the European region. Furthermore, this improved resolution was sufficient to support an epidemiology characterized by repeat introduction of measles virus rather than endemic virus spread. In conclusion, sequencing of the M-F NCR4465-4754, H8022-8621 and L10724-11438 regions of the measles virus is an efficient and useful approach for molecular surveillance of measles viruses.

Molecular Epidemiology of Measles in California, United States—2019

In 2019, the United States (US) experienced the highest number of measles importations and cases in the postelimination era. More than a quarter of imported cases entered the US through California. Measles surveillance efforts in California resulted in the identification of 26 importations, 6 outbreaks, and 72 cases in 2019. Only genotype B3 and D8 measles strains were detected. Genotype-specific differences were noted in the incidence of vaccine failures, hospitalizations, and severe complications among cases. A targeted whole genome sequencing approach provided higher-resolution discrimination between epidemiologically linked and sporadically introduced strains than conventional N450 sequencing. Our report underscores the importance of ensuring appropriate measles vaccination status, especially prior to international travel to measles-endemic regions, and highlights the value of a strong measles surveillance system in minimizing outbreaks and preserving measles elimination status in the US.

Hepatitis B Virus (Hepadnaviridae: Orthohepadnavirus: Hepatitis B virus) among Hospitalized Mentally Disabled Patients is not transmitted by their nurses or family members

Prevalence of hepatitis B virus (HBV) infection has been reported to be higher in the institutionalized mentally disabled patients than that of the general population previously reported in Iran. This study aims to investigate HBV infection among nurses and families of the hospitalized mentally disabled patients. This study was conducted on 110 nurses and family members of the mentally disabled patients who were hospitalized in five residential care centers of Tehran. The presence of hepatitis B surface antigen (HBsAg) and hepatitis B core antibody (HBcAb) was examined using the enzyme-linked immunosorbent assay (ELISA). Afterwards, HBV DNA was extracted, and then propagated via a nested polymerase chain reaction (PCR) and specific primers. Finally, a phylogenetic tree was constructed using the neighbor-joining method to compare virus genomes in the nurses' serum with other isolated HBVs worldwide. Out of 102 studied nurses, three (3%) were positive for HBsAg (100% female). Also, no patient was positive for the HBV genome, while eight (7.3%) nurses were positive for HBcAb including two (25%) males and six (75%) females. Genome sequencing of one DNA positive sample showed that the isolated virus from this patient contained sub genotype D1 and subtype ayw2. The results of none of the family members were positive for HBsAg, HBcAb, or HBV DNA. This study showed a higher prevalence of HBsAg among nurses (3%) compared to the Iranian general population (1.7-2.1%). The virus isolated from the nurses belonged to subgenotype D1 and subtype ayw2 in accordance with previous Iranian reports. Also, there was no drug-resistant or vaccine-escape mutations in the obtained viral genome. Moreover, low immune pressure on the virus in the asymptomatic chronic HBV patients might be responsible for low nucleotide divergence among the derived HBV genome.

Quantitative analysis of the splice variants expressed by the major hepatitis B virus genotypes.

Hepatitis B virus (HBV) is a major human pathogen that causes liver diseases. The main HBV RNAs are unspliced transcripts that encode the key viral proteins. Recent studies have shown that some of the HBV spliced transcript isoforms are predictive of liver cancer, yet the roles of these spliced transcripts remain elusive. Furthermore, there are nine major HBV genotypes common in different regions of the world, these genotypes may express different spliced transcript isoforms. To systematically study the HBV splice variants, we transfected human hepatoma cells, Huh7, with four HBV genotypes (A2, B2, C2 and D3), followed by deep RNA-sequencing. We found that 13–28 % of HBV RNAs were splice variants, which were reproducibly detected across independent biological replicates. These comprised 6 novel and 10 previously identified splice variants. In particular, a novel, singly spliced transcript was detected in genotypes A2 and D3 at high levels. The biological relevance of these splice variants was supported by their identification in HBV-positive liver biopsy and serum samples, and in HBV-infected primary human hepatocytes. Interestingly the levels of HBV splice variants varied across the genotypes, but the spliced pregenomic RNA SP1 and SP9 were the two most abundant splice variants. Counterintuitively, these singly spliced SP1 and SP9 variants had a suboptimal 5′ splice site, supporting the idea that splicing of HBV RNAs is tightly controlled by the viral post-transcriptional regulatory RNA element.

Molecular epidemiology of Hepatitis B virus, Hepatitis C virus, and Hepatitis D virus in general population of Afghanistan

This study gives a clue about genotypes, subgenotypes and subtypes of HBV, HCV and HDV viruses in general population of Afghanistan. A total of 234 HBsAg, 44 anti-HCV and 5 Anti-Delta positive patients belong to 25-70 age group were obtained through a rapid screening test among 5898 residents of Afghanistan. After quantifying viral load, genotyping of 61 HBV, 29 HCV and 1 HDV samples were accomplished by sequencing of a segment of the HBV Pre S, HCV NS5B, and HDV Delta antigen regions respectively. Clinically important variants of the HBV polymerase gene, the "a" determinant of HBsAg, HCV NS5B and NS3 regions were assessed. All HBV isolates were dispersed throughout the genotype D branch and ayw2 was the only subtypes found. The anti-HDV prevalence among HBsAg positive individuals was 2.2% and the single HDV sample, belonged to HDV genotype I. Analysis of HCV isolates revealed subtype HCV-1b in 75.86%, HCV-3a in 20.69% and HCV-3b in 3.44% patients. The observed mutant variants in the MHR of HBsAg were Y100 15%, Q101 5%, G102 15%, T115 45%, P120 5%, T131 5%. Likewise, S213T 10%, Q215P 5% and N248H 100% mutations were detected in the HBV polymerase region. C316N mutation was prevalent in 72.7% of HCV 1b participants. Genotypic variation in Afghan patients is in line with the ones existing in neighboring countries and regions. HBV genotypes D1, subtype ayw2, HDV RNA type I, and HCV RNA genotype 1b are likely to be dominant in Afghan patients.

Is it or is it not? Lessons learned from a case of suspected vaccine-associated measles

Background: Measles is a highly infectious viral disease that can cause serious illness and complications. Despite Australia's measles elimination status declared in 2014, the risk of acquiring measles through importation by overseas travellers who are non-immune remains. Identifying wild-type measles in a female who was recently vaccinated with measles mumps rubella (MMR) is a challenge one metropolitan Public Health Unit (PHU) experienced. Case Description: In 2018, a metropolitan Sydney PHU was notified of a positive polymerase chain reaction (PCR) result for measles on a nasopharyngeal swab for a 32 y old female who had recently received an MMR-II vaccination seven days prior to developing symptoms of measles. The case had no known epidemiological link, no recent overseas travel and no contact with recent measles cases during her incubation period. The reference laboratory ran sequencing on the clinical specimen to distinguish between wild-strain and vaccine-type measles. The results of this were inconclusive, however given the recent vaccination and inconsistent clinical symptoms and no identified epidemiological link, a decision was made to re-run the genotyping, collect additional specimens for testing, and quarantine the case until a definitive result was obtained. Subsequently, sequencing and genotyping test results revealed that this indeed was a wild-type measles strain, genotype D8. Discussion: A change in the epidemiology of measles, especially in low incidence countries like Australia, means distinguishing between wild type and vaccine–associated measles has become a new challenge, but critical in implementing a timely public health response. The initial decision to classify this case as vaccine-associated measles was based on the clinical context, epidemiological risk and inconclusive sequencing results. The lack of an epidemiological link created confusion for public health staff when investigating this case. Conclusion: This case investigation and response has demonstrated the challenge for public health with non-typical presentations of wild-type measles, particularly in people who have received one MMR. The reflection of the public health management of this case has provided an opportunity to learn from this experience and can become a valuable teaching tool for public health professionals globally, particularly in low incidence measles countries.

Measles virus circulation between the State members of the Indian Ocean Commission?

Background: Despite the availability of safe and effective vaccines, measles resurgence has been observed worldwide in 2018 and 2019. In West Indian Ocean (WIO), almost all islands have reported measles cases during these years. Vaccine coverage was particularly low in Madagascar and Comoros Island, with a single dose provided by the Expanded Program on Immunization. Because of intense exchanges between WIO islands, outbreaks observed in WIO were probably related. Methods and materials: Thanks to the Epidemic Intelligence Unit and the SEGA-One Health network of the Indian Ocean Commission (IOC), composed of five countries (Comoros, Madagascar, Mauritius, France (Reunion), and Seychelles), epidemiological data from each surveillance system were shared. Results: Measles outbreaks have successively occurred in: Mauritius (W12/2018), Madagascar (W35/2018), Reunion (W51/2018) and Comoros (W21/2019; first cases were reported early 2019). As of W41/2019, Madagascar was the most affected island with 244 557 cases (attack rate around 929/100 000) and a case fatality rate of 0,4%. Attack rate was lower in Mauritius (117/100 000) were 1 482 and 4 deaths were reported. In Reunion and Comoros, respectively 96 and 132 cases (of whom 62 were confirmed) were reported; no deaths were reported. Two measles genotypes were circulating in the region: genotype B3 in Madagascar and Comoros; genotype D8 in Mauritius; in Reunion Island both genotypes were observed. Only one case was reported in December 2018 in Seychelles were 2-dose vaccine coverage reached 99% in 2017. Conclusion: Given starting date of each outbreak and circulating genotypes, it can be assumed that outbreaks were closely related, measles virus circulating especially between Mauritius and Reunion on the one hand, and between Madagascar, Comoros and Reunion on the other hand. WIO islands are considered as an epidemiological block where pathogens easily circulate through human and animal exchanges. This situation underlines the importance of the SEGA network which should be further strengthened. For example, development of biological cooperation between WIO islands could help comprehensive epidemiological analyses in the course of outbreaks.

Epidemiological Investigation and Virus Tracing of a Measles Outbreak in Zhoushan Islands, China, 2019.

Background: Measles transmissions due to case importations challenge public health systems globally and herd immunities in all countries. In 2019, an imported measles case and its subsequently outbreak was found in the Zhoushan Islands. Here, the process of epidemiological investigation and virus tracing were summarized to provide references for the prevention and control of measles in the future.Materials and methods: The data on the demographic, epidemiological, and clinical manifestation of measles cases in this outbreak were collected. The 450 bp fragments of the measles virus (MeV) N gene were amplified and sequenced. The genome of the first imported case was further isolated. Then, the maximum-likelihood and time-scaled phylogenetic analysis was conducted.Results: A total of 28 measles cases were confirmed. Their onsets were between March 13 and May 18, 2019. The first patient was from the Ukraine. He was confirmed at the Fever Clinic in Zhoushan hospital on March 15, 2019 and at the same time, another patient had visited the hospital due to another illness and 10 days later, this second case had onset (March 25, 2019). The epidemic curve shows sustained community transmission. The majority of the following cases (19/26) were clustered on the Donggang street which was close to where the second case worked. The 22 measles virus strains successfully isolated from this outbreak all belonged to the D8.2a sub-cluster and clustered with the KY120864/MVs/GirSomnath.IND/42.16/[D8] which was the predominant genotype in the Ukraine during 2018-2019. The analysis of the complete D8 genotype genome pointed to the fact that this prevailing strain originated from India in 2015 and its substitution rate was estimated as 6.91 × 10−4 (5.64–7.98 × 10−4) nucleotide substitutions/site/year.Conclusion: This outbreak was caused by an imported case from the Ukraine. There was a possible nosocomial infection between the first case and the second case. Then, the second case played an important role in the spread of virus due to her occupation. The molecular phylogenetic analysis could help to track the origin of the virus. Increasing and maintaining the high level of vaccination coverage (≥95%) and an efficient response to imported cases are essential to prevent and control the recurrence and outbreak of measles virus.

Reduction of vaccinal coverage of measles in Brazil and the resurgence of the disease between 2017 and 2019: an epidemiological alert

Introduction: Measles a disease caused by Paramixovirus is an infectious disease with high transmissibility through the dispersion of salivary secretions from infected people. Clinically, it presents with fever, dry cough, coryza, tarsal conjunctivitis, enanthema (Koplik’s spots), maculopapular rash craniocaudally disseminated, leukopenia and other changes in blood tissue. In Brazil, the National Immunization Program (PNI), that aims vaccination coverage (CV) - population immunized against a certain disease – of 95% brought several remarkable advances for public health, such as the elimination of measles circulation in 2016, certified by the Pan American Health Organization. However, in recent years, measles has again become a serious public health problem, whose outbreaks have generated alarming data suggestive of a deficit in the integration of surveillance, prevention and promotion actions of health. Objectives: To analyze measles vaccination coverage in Brazil, during the period of 2017 to 2019; tabulate epidemiological data and identify the probable causes of measles recurrence in Brazil. Methods: Ecological retrospective study with data obtained from DataSUS (TabNet), Epidemiological Reports and Bulletins from the Health Ministry. For the analysis of the possible causes for the reintroduction of the virus, a literature review was carried out in the SciELO and PubMed databases, using the boolean operators “Vaccine” and “measles”. Articles were selected whose research location was Brazil. Articles whose methodology was not clear or well described were excluded. Results: Between 2017 and 2019, 23,751 cases in Brazil were confirmed. In 2017 vaccination coverage was 68.05%, a number that dropped to 66.95% in 2018. From 2017 to 2018, 10,262 cases were confirmed, 9,783 cases in Amazonas; 389 in Roraima; 54 in Pará; 45 in Rio Grande do Sul; 19 in Rio de Janeiro; while Sergipe, Pernambuco, São Paulo, Rondônia, Bahia and the Federal District registered four cases or less. The decline in 2019 was even more abrupt: 42.68% CV. That year 13,489 cases were confirmed in Brazil; 12,296 in São Paulo; 429 in Paraná; 155 in Rio de Janeiro; 151 in Pernambuco; 115 in Minas Gerais and 35 in Bahia. During these years, 27 deaths were confirmed in five national states: Roraima, Amazonas, Pará, Pernambuco and São Paulo. Discussion and Conclusions: The population’s lack of information regarding the severity of the disease led to a decrease in vaccination coverage (CV), this coupled with the entry of the Venezuelan genotype D8 virus into Brazilian territory, culminating in the reintroduction of measles in Brazil. In order to minimize the emergence of new cases and achieve the elimination of this pathology once more it is necessary to increase vaccination coverage to values above 95% (national vaccination coverage target according to PNI for the eradication of the disease) and to improve the integration of internal political-preventive actions so that they include the entire Brazilian population and immigrants in the fight against this disease. Key-words: Measles; Immunization; Vaccination coverage.

Hepatitis B virus detected in paper currencies in a densely populated city of India: A plausible source of horizontal transmission?

BACKGROUNDThe recent rise in the incidence of hepatitis B virus (HBV) infections in a densely populated city of eastern India (“mixing vessel” of people of varied socio-economic and immune status) prompted this study. Applying saliva on fingers for enumerating bank notes is a common practice in the Indian subcontinent. Paper notes may be a potential source of “horizontal” transmission of this virus, especially if there are cuts/bruises on the oral mucous membrane or skin. AIMTo investigate whether paper currencies could be a plausible mode of horizontal transmission of HBV infection.METHODSPolymerase chain reactions (PCR) followed by nucleotide sequencing was done for the detection of HBV. Hepatitis B virus surface antigen enzyme-linked immunosorbent assay(HBsAg ELISA) was performed on all HBV deoxyribonucleic acid-positive samples to check the detectability of the virus. Atomic force microscopy (AFM) was carried out for visual confirmation of HBV particles in ultracentrifuged/immunoprecipitated samples from currency paper washings.RESULTSHBV-specific PCRs on pellets obtained after ultracentrifugation/ immunoprecipitation of the currency paper washings detected potentially intact/viable HBV (genotype D2) in 7.14% of samples (n = 70). AFM gave the visual confirmation of HBV particles in ultracentrifuged/immunoprecipitated samples from currency paper washings. However, HBV isolates from the currency notes could not be detected by HBsAg ELISA.CONCLUSIONIt is a common practice in the Indian subcontinent to count paper currencies by applying saliva on fingertips. Paper notes may be a potential source of “horizontal” transmission of this virus, especially if there are cuts/bruises on the oral mucous membrane or skin, but it was practically not possible to demonstrate experimentally such transmission. Detection of potentially intact/viable and “occult” HBV from currency poses potential risk of silent transmission of this virus among the general population.

Comparative analysis of developing grain transcriptome reveals candidate genes and pathways improving GPC in wheat lines derived from wild emmer.

The grain protein content (GPC) in modern wheat is inherently low. Wild emmer wheat (Triticum turgidum ssp. dicoccoides, 2n = 4x = 28, AABB) gene pool harbors wide genotypic variations in GPC. However, the characterization of candidate genes associated with high GPC is a challenge due to the complex characteristic of this trait. In the current study, we performed RNA-seq analysis on developing grains of wild emmer genotype D1, common wheat CN16, and their hexaploid wide hybrid BAd107-4 with contrasting GPC. We have found a total of 39,795 expressed genes on chromosomes A and B, of which 24,152 were shared between D1, CN16, and BAd107-4. From 1744 differentially expressed genes (DEGs), 1203 were downregulated and 541 were upregulated in the high GPC (D1+BAd107-4) compared with low GPC (CN16) groups. The majority of DEGs were associated with protein processing in endoplasmic reticulum, starch and sucrose metabolism, galactose metabolism, and protein export pathways. Expression levels of nine randomly selected genes were verified by qRT-PCR, which was consistent with the transcriptome data. The present database will help us to understand the potential regulation networks underlying wheat grain protein accumulation and provide the foundation for simultaneous improvement of grain protein content and yield in wheat breeding programs.

A Major Regional Measles Outbreak: Description of Hospitalized Cases in 2017–2018 at Bordeaux University Hospital, France

BackgroundMeasles remains endemic worldwide, despite current vaccination recommendations, and is associated with high morbidity and mortality rates. We describe all cases hospitalized in Bordeaux University Hospital (BUH), the starting point of a national significant measles outbreak in 2017–2018.MethodsIn this retrospective study, we included all patients hospitalized in BUH from September 1, 2017, to May 31, 2018. Inclusion criteria were age >1 year, clinical symptoms, and biological confirmation by measles immunoglobulin M or measles reverse transcription polymerase chain reaction positivity.ResultsWe included 171 patients. Most patients were immunocompetent; only 19% had preexisting medical histories. Most patients had rash and fever (97%), but some cases were atypical and difficult to diagnose. Köplik’s spots were reported in 66 cases (38%). The most frequent biological markers were blood inflammation markers (96%) and lymphopenia (81%). Unexpectedly, we found hyponatremia (<135 mmol/L) in 40% of patients. We identified peaks in January and March, corresponding to 76 D8 genotypes and 28 B3 strains. The following complications were reported in 65 patients (38%): pneumonia, hepatitis, and keratitis; 10 had neurological symptoms. One patient had Guillain-Barré syndrome, and a young immunocompromised patient died from measles inclusion-body encephalitis. Most of the patients (80%) had not been correctly vaccinated, including 28 health care workers. Some patients (n = 43, 25%) developed measles despite having plasma IgG. These included 12 possible vaccination failure cases.ConclusionsDuring the BUH outbreak, measles was often complicated and sometimes atypical. Vaccination coverage was dramatically insufficient. We also describe vaccination failure cases that must be better investigated.

Investigation of Measles Outbreak among Thai and Migrant Workers in Two Factories in Nakhon Pathom, Thailand, 2019.

On 22 March 2019 the Thai Department of Disease Control (DDC) was notified that 16 workers, including Thai and Myanmar migrant workers, from two factories located in Nakhon Phathom Province, had presented with a fever with rash during the previous 2 weeks. Active case finding was conducted among workers in both factories using face-to-face interviews. Suspected cases were defined as a worker who developed fever with rash with one of the following symptoms: cough, coryza or conjunctivitis. Testing for measles IgM antibodies and viral identification through throat swabs by polymerase chain reaction (PCR) were performed to confirm diagnosis. Vaccination history among cases was reviewed. Nationality and age-specific attack rates (AR) were calculated. An environmental study and a social network analysis were conducted to better understand the transmission process. A total 56 cases (AR = 0.97%) were identified. Of 21 serum measles IgM collected, 8 (38.0%) were positive. Of 8 throat swabs collected, 5 (62.5%) were positive for measles genotype D8. The disease attack rate in migrant employees was twice as large as the rate in Thai counterparts (AR = 0.7 and 1.4%). The first case was identified as a Myanmar worker who arrived in Thailand two weeks prior to his illness. The Myanmar workers’ accommodation was more crowded than that for Thai workers. The hot spots of transmission were found at a drinking water tank which had shared glasses. Among the cases, 62.5% could not recall their vaccination history, and 25% had never had an injection containing a measles vaccination. The majority of migrant cases had never completed a two-dose measles vaccination. To halt the outbreak, measles vaccines were administered to the employees, particularly those working in the same sections with the cases and shared glasses were removed. For future policy action, a vaccination program should be incorporated into the work permit issuance process.

Molecular genetic analysis of the strain Leningrad-16 used for the production of measles vaccine

Aim. To study the genetic stability of the measles virus strain Leningrad-16 (L-16) used for the production of vaccine at JSC NPO Mikrogen.Materials and methods. A series of production and sowing strains of L-16 (JSC NPO Mikrogen), ready-made series of measles vaccines from various manufacturers, and the strain of measles virus genotype D6 were studied. Molecular genetic study of the strains was performed using RT-PCR followed by restriction analysis and sequencing.Results. The complete genome sequences of the production and sowing strains of L-16 that are used for vaccine production were obtained. The sequence of the vaccine strain was deposited in GenBank. Strain L-16 was confirmed to be genetically stable. The obtained data demonstrated the possibility of using the RT-PCR method with subsequent restriction analysis to confirm the authenticity of the vaccine strain L-16 in finished mono and three component vaccines.Conclusion. The results of the study suggest the applicability of the molecular genetic methods to confirm the authenticity of the studied strains not only at the production stages, but also in the finished series of vaccines.

Complete Genome Sequence of a Precore-Defective Hepatitis B Virus Genotype D2 Strain Isolated in Bangladesh.

Hepatitis B virus (HBV) genomic mutations affect viral replication, disease progression, and diagnostic and vaccination efficiency. There is limited information regarding characterization and mutational analysis of HBV isolated in Bangladesh. Here, we report the complete nucleotide sequence of a precore-defective HBV genotype D2 strain isolated in Bangladesh.

Measles Virus Imported by International Traveler in Jiangsu Province of China, in 2018 and 2019.

Measles remains a public health concern in many regions, and the imported measles cases continue to challenge the measles elimination program for most of the countries where measles was verified to be eliminated or approaching elimination. The imported measles cases have been reported since October, 2017, in Jiangsu province, China. In this study, we reported the first imported B3 genotype measles virus from Egypt and the second imported D8 genotype measles virus from Philippines through international traveling. No secondary measles cases were found after these imported cases. Our findings highlighted the importance of measles vaccination targeting international travelers in China.

Characterization of diversity of measles viruses in India: Genomic sequencing and comparative genomics studies

To map genomic diversity of Measles virus (MeV) isolates collected during 2009-2017 from ten states of India. Genome sequencing of Indian isolates and comparative genomics with global MeV using phylogeny, population stratification and selection pressure approaches were performed. The first report of complete genome sequences of forty-three Indian MeV isolates belonging to genotypes D4 (eight) and D8 (thirty-five). Three Indian isolates mapped to named strains D4-Enfield, D8-Villupuram and D8-Victoria. Indian D4 isolates deviate from standard genome length due to indels in M-F intergenic region. Estimated nucleotide substitution rates of Indian MeV derived using genome and individual genes are lower than that of global isolates. Phylogeny revealed genotype-based temporal clustering, suggesting existence of two lineages of D4 and three lineages of D8 in India. Absence of spatial clustering suggests role of cross-border travel in MeV transmission. Evolutionary analyses suggest the need for surveillance of MeV in India, particularly in view of diversified trajectories of D4 and D8 isolates. This study contributes to global measles epidemiology and indicates no major impact on antigenicity in Indian isolates, thereby substantiating the use of current vaccines to meet measles elimination target of 2023 set by World Health Organization for South-East Asia Region.

Measles surveillance activities in the Metropolitan Area of Milan during 2017-2018.

SummaryIntroductionIn Italy, the transmission of measles is still endemic, and 7,919 cases were reported to the National Surveillance System between January 2017 and December 2018. Aim of this study is to report the results of the measles surveillance activities in the Metropolitan City of Milan from March 2017 to December 2018, and to evaluate the surveillance performance WHO indicators.MethodsThe Local Health Units (LHUs) carried out case investigations and collected specimens to send to the EpiSoMI Lab (Subnational Reference Laboratory, SRL) of the University of Milan for cases/outbreaks confirmation and genotyping performed according to the WHO Guidelines.ResultsOverall, 610 suspected measles cases were reported by the surveillance system of the Metropolitan City of Milan. A total of 439 out of 540 cases with adequate specimens were laboratory-confirmed by molecular and/or serological assays. Two-hundred and thirty-six cases were notified as sporadic and 203 as related to 94 outbreaks. The most confirmed cases were aged 15–39 years, almost all not vaccinated. Overall, 282 cases were genotype D8 and 118 genotype B3.The evaluation of a set of indicators to monitor the quality of surveillance activities demonstrated the proficiency of the EpiSoMI Lab.ConclusionsA well-done investigation of cases and outbreaks by the surveillance local system, in a timely manner, in order to notify and investigate suspected cases and to laboratory confirm or discard cases is fundamental to reduce morbidity, to prevent further virus transmission and to achieve measles elimination.