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Introduction: Human parvovirus B19 (B19V) has an affinity for multiple organs and causes a myriad of clinical diseases depending on the host’s immunological and haematological status. The seroprevalence of human parvovirus B19 has mostly been studied in haematological disorders, but there is still a lack of data on B19V seroprevalence in extra-haematological disorders. Aim: To study the seroprevalence of B19V in haematological and extra-haematological disorders. Materials and Methods: This retrospective observational study was conducted at the Microbiology Laboratory of Sanjay Gandhi Postgraduate Institute of Medical Sciences (SGPGIMS), Lucknow, Uttar Pradesh, India. Data was collected from September 2017 to September 2020, and data analysis was done from October 2020 to January 2021. A total of 702 serum samples from patients suspected of B19V infection were received over a threeyear duration for parvovirus B19 antibody testing. Of these, 674 serum samples were included in the study as per the inclusion and exclusion criteria. The prevalence of B19V antibodies in different clinical disorders was investigated by collecting patient details like age, gender, underlying clinical disorder, and B19Vspecific Immunoglobulin M (IgM) and IgG antibodies detected by quantitative enzyme immunoassay on all serum samples suspected of B19V infection using Statistical Package for Social Sciences (SPSS) version 25.0 software. The Chi-square test was used to analyse statistically significant variables. Results: B19V-specific IgM and IgG antibodies were detected in 35.7% (241/674) of the serum samples received over a three-year duration. The positivity rate was 94 (13.9%) for IgG, 108 (16%) for IgM, and 39 (5.8%) for both IgG and IgM. The positivity in adults aged 18 years and over (39.6% or 160/404) was statistically significantly higher compared to children aged 17 years and younger (30% or 81/270) (p=0.0109). Among the 241 B19V-positive patients, 126 (52.3%) had haematological disorders, and 115 (47.7%) had extra-haematological disorders. The total positivity of IgG plus IgM antibodies was highest in musculoskeletal and connective tissue disorders (33 (54.1%) and haematological disorders 126 (48.3%). Conclusion: The B19V seroprevalence was relatively low in the present study compared to most serological studies conducted in other regions. The present study provides information on the seroprevalence of B19V in both haematological and extrahaematological disorders simultaneously. [ABSTRACT FROM AUTHOR]

Background: Rickettsial infections remain one of the most neglected and underdiagnosed tropical diseases in the developing countries. Scrub typhus can prove to an important diagnosis in pyrexia of unknown origin (PUO) patients and is transmitted by a species of trombiculid mites ("chiggers"). The disease leads to a plethora of symptoms like fever, rash, headache, nausea, abdominal pain, thrombocytopenia, etc. The current study was aimed to assess the seroprevalence as well as other demographic parameters of scrub typhus among patients diagnosed with PUO in the northern part of India. Materials and Methods: This study was undertaken for a period of 3 years from September 2017 to September 2020. Serum samples of suspected cases were tested for IgM Scrub typhus along with other common febrile illnesses like Malaria, typhoid, dengue, leptospirosis, chikengunya, etc. Additional testing for COVID-19 was also planned for samples received after February 2020. Results: The overall seroprevalence of Scrub typhus during the 3 year study period was noted to be 18.6% in the PUO patients. Typhoid was noted in 39.5%, malaria in 9.2%, Dengue in 13.5%, leptospirosis in 4.8%, and chikungunya in 5.3% of the patients. No cause was identified in 9.1% of the PUO cases. 3.9% of the samples were positive by RT-PCR for COVID-19. No mortality was noted in the scrub typhus positive cases. Conclusion: Scrub typhus is an emerging tropical rickettsial disease in the Indian subcontinent. The present study highlights the importance of screening of PUO cases for this important infection as timely institution of simple empirical treatment can prove to be life saving in such positive cases. [ABSTRACT FROM AUTHOR]

Background: Human parvovirus B19V is a DNA virus, and a member of the family Parvoviridae, that causes various clinical manifestations, from asymptomatic to persistent infection that is associated with different autoimmune diseases. The parvovirus B19 evolves with a very high mutation rate that is closer to those of existing RNA viruses. Globally circulating B19V is currently classified into three genotypes, but their distribution is not spatially and temporally correlated. Except for a few recent reports on B19V entry into the human host and its genetic diversity, there is a lack of sufficient studies on this virus from distinct geographical locations and no clear understanding of its evolution has been documented. Methods: To better understand the evolution of the Human parvo B19V virus from India's southern part, a geographically distinct location with no reports of B19V genomes, we have screened for B19V in 456 suspected cases using VP1/2 surface marker genes, and its characteristics were studied in detail. Amongst 456 clinically suspected B19V samples, 7.2% (33/456) were found positive by nested PCR (nPCR) were subsequently validated by real-time PCR, Sanger sequencing, and metagenome analysis. Results: Human parvovirus B19 infection was shown among 33 of 456 patients when tested by nPCR; 30 among these were also positive by qPCR and were subsequently confirmed by sequencing 75% nPCR positive samples and 76% qPCR positive samples were from patients with age. ≥ 50 years respectively (Additional file 1: Table S1). The complete VP1/2 gene assembly from the South Indian strain showed three novel mutations (T122A, V128I, I283V), which might significantly impact the stability and virulence of the B19V virus circulating in this part of the world. These mutations might be crucial for its adaptive evolutionary strategies facilitating the spread and infectivity potential of the virus. In maximum likelihood phylogeny of VP1/2 sequences, the South Indian B19V strain forms a separate clade closer to the existing genotype two strains circulating worldwide. Conclusion: Our study contributes to a better understanding of the human parvovirus's genetic and evolutionary characteristics in South India. Also, it highlights the possibility that a positive selection pressure acting on VP1/2 could increase the survival and replication capabilities of the viruses. [ABSTRACT FROM AUTHOR]

Acute parvovirus B19 infection can cause acute symmetric polyarthritis indistinguishable from polyarticular rheumatoid arthritis. Most cases of acute arthritis due to parvovirus B19 are self-limiting and resolve with symptomatic treatment. We present a 65-year-old lady from Southern India who presented with history of fever and joint pain for 10 days. Clinical examination revealed symmetric inflammatory arthritis involving the appendicular skeleton with predominant involvement of bilateral metacarpophalageal joints. Laboratory investigations revealed elevated inflammatory markers with negative serology for rheumatoid arthritis. Parvovirus B19 IgM antibody tested positive. She was initiated on nonsteroidal anti-inflammatory drugs with which her symptoms resolved completely. [ABSTRACT FROM AUTHOR]

The core component of every blood program is the establishment of a system to ensure the safe supply of blood and blood products. Parvovirus B19 (B19V) is one of the emerging blood-borne pathogens in recent times. In India, routine screening of B19V is not done for blood and blood products. The objective of this study is to determine the serostatus of B19V among blood donors at a tertiary care hospital in Chennai, South India. This is a cross-sectional study. A total of 100 samples were collected from blood donors. Ethical clearance was obtained from the Institutional Ethics Committee. Serum was separated by centrifuging at 1000g and stored at -80oC. Serum samples were screened for anti-human B19V IgM and IgG antibodies using semi- quantitative ELISA (Novalisa, ©Novatec, Germany). The purified antigens coated in the wells were VP-1S, VP-C, and VP-N; a part of the VP1 & NS1 protein of the virus. The test was performed as per kit instructions. The serostatus of blood donors was recorded. Of the 100 samples tested using ELISA, 45% were found to be B19V IgG positive and 24% were found to be B19V IgM positive. About 8% of the samples were positive for both B19V IgM and IgG, indicating recurring infection. Of the samples tested, there were 14% of the people who were positive for B19V IgM and not IgG. The mean age of the participants is 29.3 years. All participant blood donors were male. B19V infection can result in serious complications in high-risk groups. This includes hydrops fetalis in pregnant women, chronic anaemia & transient aplastic crisis in patients with haematological problems and immunodeficient patients. These are the patients who require constant multi-transfusion. However, in most countries, including India, the screening of donors is not mandatory. There is evidence of long-term B19V persistence in blood circulation and tissues of both the immunocompromised and immunocompetent. This study demonstrates the importance of screening to eliminate the risk of transmission through transfusion. Systematic surveillance of the virus in blood and blood products will lead to improved health outcomes in vulnerable populations. [ABSTRACT FROM AUTHOR]

Background and Aim: Parvovirus-B19 disease in immunocompromised children can cause myelosuppression and therapeutic delays. We studied the clinical profiles of children having symptoms suggestive of parvoviral disease at our institution, a large tertiary cancer center., Methods: Children below age 15 years undergoing treatment for malignancies with clinical features suggestive of parvoviral infection, and/or unexplained drop in hemoglobin, and/or prolonged cytopenia were screened for parvovirus infection using DNA-PCR for parvovirus-B19 (PB19) in the peripheral blood. Patients testing positive from September 2014 till February 2017 were studied., Results: Of the 59 patients (36 patients with hematolymphoid malignancies, 23 with solid tumors) screened for suspected parvoviral infections, 27 tested positive. Median age was 9.6 years (2.25-15 years), 18 (66%) had hematolymphoid malignancies, while 7 (33%) had solid tumors. Six patients (26%) were on intensive phases, 16 (60%) patients developed the symptoms during maintenance chemotherapy, and 4 (15%) after completion of therapy. Isolated anemia was the commonest feature seen in 10 patients (37%) while bicytopenia and pancytopenia were noticed in 8 (30%) and 9 (33%) patients respectively. Fifty percent of patients those who received rituximab (3/6) developed persistent parvoviremia (>4 weeks) as compared with 24% (5/21) of those who did not. Two patients (7%) developed hemophagocytic lymphohistiocytosis (HLH). Treatment delay by more than 14 days was encountered in a majority (62%), with 5 patients requiring treatment modification or even suspension., Conclusions: Parvoviral infection in children who are on or have recently completed chemotherapy can lead to multiple cytopenias and significant treatment delays. Rituximab exposure may lead to persistent parvoviral disease (p < 0.05). HLH, though occasional, can be a serious complication., (© 2018 Wiley Periodicals, Inc.)

Human parvovirus B19 (B19V) causes myriads of clinical diseases; however, owing to lack of awareness and undetermined clinical impact, it has failed to become a virus pathogen of global concern. Cryptically, B19V causes significant morbidity and mortality. Half of the world population and 60 per cent of Indians are known to be serologically naive and are at risk of acquiring B19V infections. Cumulatively, our data showed 21.3 per cent B19V-infected patients with juvenile chronic arthropathy, recurrent abortions, multi-transfused thalassaemia and leukaemia. In addition, B19V-infected cases that ended fatally included patients with pure red cell aplasia, fulminant hepatitis and haemophagocytic syndrome. Novel clinical associations of B19V observed were amegakaryocytic thrombocytopaenia, myositis and non-occlusive ischaemic gangrene of bowel. B19V possesses multiple receptors which are distributed widely in human tissues. Vascular endothelial cell infection by B19V causes endothelialitis and vasculitic injuries besides antibody-dependent enhancement which empowered B19V to cause multiorgan diseases. Owing to lack of suitable animal model for B19V, true causal role remains to be determined, but numerous reports on B19V infections substantiate a causal role in multiorgan diseases. Hence, B19V infections need to be recognized, investigated and treated besides making efforts on vaccine developments., Competing Interests: None

Objectives: The present study was aimed to find out the prevalence of parvovirus B19  amongst healthy blood donors and blood transfusion recipients so as to determine the feasibility of providing seronegative blood components to vulnerable recipients., Methods: A total of 1000 samples were studied which included 800 blood donors and 200 transfusion recipients.The transfusion recipients included 100 multitransfused patients and 100 non transfused controls.All samples were subjected to parvovirus B19 ELISA for IgG and IgM antibodies., Results: Of the 800 blood donors,663(82.9%) were voluntary while 137(17.1%) were replacement donors.The seroprevalence of B19V IgG antibodies among healthy blood donors was found to be 34.1% whilst that of IgM antibodies was 1.4%.The seroprevalence of B19 V IgG antibodies was found to be 28.4% in the age group 18-35 years and 42.1% in donors more than 35 years of age(p ≤ 0.01). The overall seroprevalence of IgG antibodies in multitransfused patients was 34% and IgM antibodies was 7.0%.The B19 V IgG prevalence was 20% in the transfused patients aged 0-20 years and 48% in patients above 20 years of age (p ≤ 0.05)., Conclusion: The moderately high seroprevalence of B19 V IgG in blood donors and patients suggests endemicity of infection.However, prevalence of B19 V IgM antibodies in blood donors is low.With the widespread use of pooled plasma derived medicinal products and recognition of severe pathological effects in susceptible recipients, transfusion transmission of B19 V has become a major concern in the past few decades.We suggest screening of blood units to identify B19 V IgM negative units for transfusion to selected patients., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Human parvovirus B19 (B19V) has been associated with chronic anemia in immuno-compromised patients. In the present study, the prevalence and genotype distribution of B19V in children from North India, suffering with hemato-oncological disorders is reported. Children with aplastic anemia/leukemia/chronic hematological disorders, and healthy blood donors were enrolled in the study. Blood samples from cases and blood donors were analyzed for anti-B19V IgM and anti-B19V IgG antibodies by ELISA and for B19V-DNA by PCR. B19V-DNA positive samples were studied further for determination of viral load in samples and for B19V-DNA sequence (VP1/VP2 overlapping region) analysis. Total 238 cases (103 leukemia, 77 aplastic anemia and 58 chronic hematological disorders) and 350 blood donors were enrolled in the study. Anti-B19V IgM was positive in 16 (6.7%) cases, B19V-DNA was detected in 13 (5.5%) cases and anti-B19V IgG was positive in 127 (53.4%) cases. Total 223 (63.5%) blood donors were positive for anti-B19V IgG, however, anti-B19V IgM and B19V-DNA was not detected in any blood donor. The prevalence of anti-B19V IgG was significantly higher in children > 10 years of age. Viral load of B19V decreased with appearance of specific antibodies. Phylogenetic analysis of the VP1/VP2 overlapping region revealed that genotype 1 predominated in these patients (11/13, 84.6%), followed by genotype 3 (2/13, 15.4%). No genotype 2 was detected. All the genotype 1strains were sub-typed as 1a, except four strains, which matched neither 1a nor 1b and formed a separate cluster. Both the genotype 3 strains were sub-typed as 3b., (© 2014 Wiley Periodicals, Inc.)