#Hemagglutinin and #neuraminidase #antibodies are induced in an #age- and subtype- dependent manner after #influenza virus infection (J Virol., abstract)

[Source: Journal of Virology, full page: (LINK). Abstract, edited.]

Hemagglutinin and neuraminidase antibodies are induced in an age- and subtype- dependent manner after influenza virus infection.

Sook-San Wong, Ben Waite, Jacqui Ralston, Tim Wood, G Edwin Reynolds, Ruth Seeds, E. Claire Newbern, Mark G. Thompson, Q. Sue Huang, Richard J. Webby, the SHIVERS Investigation Team

DOI: 10.1128/JVI.01385-19



Despite evidence that antibodies targeting the influenza virus neuraminidase (NA) protein can be protective and are broadly cross-reactive, the immune response to NA during infection is poorly understood compared to the response to hemagglutinin (HA) protein. As such, we compared the antibody profile to HA and NA in two naturally-infected human cohorts in Auckland, New Zealand; a serosurvey cohort, consisting of pre- and post-influenza season sera from PCR-confirmed influenza cases (n=50), and an immunology cohort, consisting of paired sera collected after PCR-confirmation of infection (n=94). The induction of both HA and NA-antibodies in these cohorts was influenced by age and subtype. Seroconversion to HA was more frequent in those < 20 years old (yo) for influenza A (Serosurvey, p=0.01, Immunology, p=0.02), but not influenza B virus infection. Seroconversion to NA was not influenced by age or virus type. Adults ≥ 20 yo infected with influenza A viruses were more likely to show NA-only seroconversion compared to children (56% vs 14% [5 – 19 yo] and 0% [0 – 4 yo] respectively). Conversely, children infected with influenza B viruses were more likely than adults to show NA-only seroconversion (88% [0 – 4 yo] and 75% [5 – 19 yo] vs 40% [ ≥ 20 yo]). These data indicate a potential role for immunological memory in the dynamics of HA and NA-antibody responses. A better mechanistic understanding of this phenomenon will be critical for any future vaccines aimed at eliciting NA immunity.



Data on the immunologic responses to neuraminidase (NA) is lacking when compared to what is available on hemagglutinin (HA) responses, despite growing evidence that NA-immunity can be protective and broadly cross-reactive. Understanding these NA responses during natural infection is key to exploiting these properties for improving influenza vaccines. Using two community-acquired influenza cohorts, we showed that the induction of both HA and NA-antibody after infection is influenced by age and subtypes. Such response dynamics suggests the influence of immunological memory and understanding how this process is regulated will be critical to any vaccine effort targeting NA-immunity.

Copyright © 2020 Wong et al. This is an open-access article distributed under the terms of the Creative Commons Attribution 4.0 International license.

Keywords: Seasonal Influenza; Serology; Seroprevalence.


#Serological #Evidence of #Yersiniosis, #TBE, #WNV, #Hepatitis E, #CCHF, Lyme #Borreliosis, and #Brucellosis in Febrile Patients Presenting at Diverse Hospitals in #Kenya (Vector Borne Zoo Dis., abstract)

[Source: Vector-Borne and Zoonotic Diseases, full page: (LINK). Abstract, edited.]

Serological Evidence of Yersiniosis, Tick-Borne Encephalitis, West Nile, Hepatitis E, Crimean-Congo Hemorrhagic Fever, Lyme Borreliosis, and Brucellosis in Febrile Patients Presenting at Diverse Hospitals in Kenya

Josphat Nyataya, Moureen Maraka, Allan Lemtudo, Clement Masakhwe, Beth Mutai, Kariuki Njaanake, Benson B. Estambale, Nancy Nyakoe, Joram Siangla, and John Njenga Waitumbi

Published Online: 13 Jan 2020 / DOI: https://doi.org/10.1089/vbz.2019.2484



Data on pathogen prevalence is crucial for informing exposure and disease risk. We evaluated serological evidence of tick-borne encephalitis (TBE), West Nile (WN), Hepatitis E virus (HEV), Crimean-Congo Hemorrhagic Fever (CCHF), Yersiniosis, Lyme Disease (LD), and brucellosis in 1033 patients presenting with acute febrile illness at 9 health care facilities from diverse ecological zones of Kenya: arid and semiarid (Garissa District Hospital, Lodwar District Hospital, Marigat District Hospital, Gilgil District Hospital), Lake Victoria basin (Kisumu District Hospital, Alupe District Hospital, Kombewa Sub-County Hospital), Kisii highland (Kisii District Hospital), and coastal (Malindi District Hospital). Epidemiological information of the patients such as geography, age, gender, and keeping animals were analyzed as potential risk factors. Of the 1033 samples, 619 (59.9%) were seropositive to at least one pathogen by IgM (current exposure), IgG/IgM (recent exposure), and IgG (past exposure). Collective seroprevalence for current, recent, and past to the pathogens was 9.4%, 5.1%, and 21.1% for LD; 3.6%, 0.5%, and 12.4% for WN; 0.9%, 0.5%, and 16.9% for HEV; 5.8%, 1.3%, and 3.9% for brucellosis; 5.7%, 0.2%, and 2.3% for yersiniosis; 1.7%, 0%, and 6.2% for TBE; and 0.4%, 0%, and 1.9% for CCHF. Brucellosis risk was higher in patients recruited at Garissa District Hospital (odds ratio [OR] = 3.41), HEV (OR = 2.45) and CCHF (OR = 5.46) in Lodwar District Hospital, LD in Alupe District Hospital (OR = 5.73), Kombewa Sub-district hospital (OR = 8.17), and Malindi District hospital (OR = 3.3). Exposure to LD was highest in the younger age group, whereas yersiniosis did not vary with age. Age was a significant risk for WN, brucellosis, CCHF, TBE, and HEV and in those aged >14 years there was an increased risk to WN (OR = 2.30, p < 0.0001), brucellosis (OR = 1.84, p = 0.005), CCHF (OR = 4.35, p = 0.001), TBE (OR = 2.78, p < 0.0001), and HEV (OR = 1.94, p = 0.0001). We conclude that LD is pervasive and constitutes a significant health burden to the study population, whereas yersiniosis and CCHF are not significant threats. Going forward, community-based studies will be needed to capture the true seroprevalence rates and the associated risk factors.

Keywords: Arbovirus; WNV; CCHF; Borreliosis; TBE; Brucellosis; Seroprevalence; Kenya.


#Persistence of #H7N9 virus #antibody response 2 years after #infection (Influenza Other Respir Viruses, abstract)

[Source: US National Library of Medicine, full page: (LINK). Abstract, edited.]

Influenza Other Respir Viruses. 2019 Dec 19. doi: 10.1111/irv.12702. [Epub ahead of print]

Persistence of H7N9 virus antibody response 2 years after infection.

Yao L1, Wang GL1, Chen LL2, Liu C2, Duan LJ1, Gray GC3,4,5, Ma MJ1.

Author information: 1 State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China. 2 Suzhou Municipal Center for Disease Control and Prevention, Suzhou, China. 3 Division of Infectious Diseases, School of Medicine, Global Health Institute, Duke University, Durham, North Carolina. 4 Global Health Research Center, Duke-Kunshan University, Kunshan, China. 5 Program in Emerging Infectious Diseases, Duke-NUS Medical School, Singapore City, Singapore.



We measured antibodies against H7N9 virus 2 years after infection in 14 patients who were infected during October 2016-September 2017. Approximately 2 years after infection, antibody titers ≥10 were detectable in 13 (92.9%) patients. Three (21.4%) of 14 patients had hemagglutination inhibition titers ≥40, and their geometric mean titer (GMT) was 20 (95% CI 15.7-28.1), whereas 10 (71.4%) and all 14 (100%) of the 14 patients had titers ≥40, and GMTs at 34.4 (95% CI 25.7-51.2) and 73.45 (54.7-106.7) for neuraminidase inhibition and microneutralization antibodies, respectively. Our findings suggest that H7N9 infection may induce long-term antibody response at least 2 years after infection.

© 2019 The Authors. Influenza and Other Respiratory Viruses Published by John Wiley & Sons Ltd.

KEYWORDS: H7N9 viruses; antibody response; influenza A virus; persistence; serological

PMID: 31856341 DOI: 10.1111/irv.12702

Keywords: Avian Influenza; H7N9; Human; Serology.


#Surveillance of #swine #influenza viruses in sentinel #familial #farms in Hung Yen province in Northern #Vietnam in 2013-2014 (Zoonoses Public Health, abstract)

[Source: US National Library of Medicine, full page: (LINK). Abstract, edited.]

Zoonoses Public Health. 2019 Dec 19. doi: 10.1111/zph.12671. [Epub ahead of print]

Surveillance of swine influenza viruses in sentinel familial farms in Hung Yen province in Northern Vietnam in 2013-2014.

Baudon E1,2, Peyre M2, Tung DD3, Thi Nga P3, Khong NV3, Cowling BJ1, Peiris M1.

Author information: 1 The University of Hong Kong, Hong Kong, China. 2 French Agricultural Research Center for International Development (CIRAD), Montpellier, France. 3 National Institute of Veterinary Research, Hanoi, Vietnam.



From May 2013 to April 2014, 15 swine family-run farms (17 pig litters) in two districts in Hung Yen province, near Hanoi, were virologically and epizootiologically monitored for swine influenza viruses (SIV) monthly. No SIV was isolated from nasal swabs. Maternal antibodies were detected in 10 litters, and seroconversion against SIV was detected in six litters. There was a marked difference in patterns of SIV transmission in the two districts. Van Lam district which has low density of swine with mainly smallholder farms had low intensity of SIV, with much of the infection caused by H1N1 2009 pandemic-like viruses A(H1N1)pdm09, likely originated from humans. In contrast, Van Giang district, which has high swine density and larger farms, had high levels of typical SIV (triple reassortants H3N2 and H3N2 Binh Duong lineage viruses) circulating within swine. With one exception, the SIV lineages detected were those we concurrently isolated from studies in a large central abattoir in Hanoi. Influenza-like illness symptoms reported by farmers were poorly correlated with serological evidence of SIV infection.

© 2019 Blackwell Verlag GmbH.

KEYWORDS: Vietnam; familial farm; maternal antibody; surveillance; swine influenza; value chain

PMID: 31855326 DOI: 10.1111/zph.12671

Keyword: Swine Influenza; Influenza A; H1N1pdm09; H3N2; Serology; Pigs; Vietnam.


Middle East respiratory syndrome #coronavirus (#MERS-CoV) neutralising #antibodies in a high-risk #human #population, #Morocco, November 2017 to January 2018 (Euro Surveill., abstract)

[Source: Eurosurveillance, full page: (LINK). Abstract, edited.]

Middle East respiratory syndrome coronavirus (MERS-CoV) neutralising antibodies in a high-risk human population, Morocco, November 2017 to January 2018

Anass Abbad 1,2,7, Ranawaka APM Perera 3,7, Latifa Anga 1, Abdellah Faouzi 1, Nhu Nguyen Tran Minh 4, Sk Md Mamunur Rahman Malik 4, Nadia Iounes 2, Abderrahmane Maaroufi 1, Maria D Van Kerkhove 5, Malik Peiris 3,6, Jalal Nourlil 1

Affiliations: 1 Medical Virology and BSL-3 Laboratory, Institut Pasteur du Maroc, Casablanca, Morocco; 2 Laboratoire d’Ecologie et d’Environnement, Faculté des Sciences Ben M’Sik, Université Hassan II, Casablanca, Morocco; 3 School of Public Health, University of Hong-Kong, Hong Kong SAR, China; 4 Health Emergencies Programme, World Health Organization, Regional Office for the Eastern Mediterranean, Cairo, Egypt; 5 Health Emergencies Programme, World Health Organization, Geneva, Switzerland; 6 HKU-Pasteur Research Pole, University of Hong Kong, Hong Kong SAR, China; 7 These authors contributed equally to this work

Correspondence:  Malik Peiris  ; Jalal Nourlil

Citation style for this article: Abbad Anass, Perera Ranawaka APM, Anga Latifa, Faouzi Abdellah, Minh Nhu Nguyen Tran, Malik Sk Md Mamunur Rahman, Iounes Nadia, Maaroufi Abderrahmane, Van Kerkhove Maria D, Peiris Malik, Nourlil Jalal. Middle East respiratory syndrome coronavirus (MERS-CoV) neutralising antibodies in a high-risk human population, Morocco, November 2017 to January 2018. Euro Surveill. 2019;24(48):pii=1900244. https://doi.org/10.2807/1560-7917.ES.2019.24.48.1900244

Received: 14 Apr 2019;   Accepted: 06 Oct 2019




Middle East respiratory syndrome coronavirus (MERS-CoV) remains a major concern for global public health. Dromedaries are the source of human zoonotic infection. MERS-CoV is enzootic among dromedaries on the Arabian Peninsula, the Middle East and in Africa. Over 70% of infected dromedaries are found in Africa. However, all known zoonotic cases of MERS have occurred in the Arabian Peninsula with none being reported in Africa.


We aimed to investigate serological evidence of MERS-CoV infection in humans living in camel-herding areas in Morocco to provide insights on whether zoonotic transmission is taking place.


We carried out a cross sectional seroprevalence study from November 2017 through January 2018. We adapted a generic World Health Organization MERS-CoV questionnaire and protocol to assess demographic and risk factors of infection among a presumed high-risk population. ELISA, MERS-CoV spike pseudoparticle neutralisation tests (ppNT) and plaque neutralisation tests (PRNT) were used to assess MERS-CoV seropositivity.


Serum samples were collected from camel slaughterhouse workers (n = 137), camel herders (n = 156) and individuals of the general population without occupational contact with camels but living in camel herding areas (n = 186). MERS-CoV neutralising antibodies with ≥ 90% reduction of plaque numbers were detected in two (1.5%) slaughterhouse workers, none of the camel herders and one individual from the general population (0.5%).


This study provides evidence of zoonotic transmission of MERS-CoV in Morocco in people who have direct or indirect exposure to dromedary camels.

©  This work is licensed under a Creative Commons Attribution 4.0 International License.

Keywords: MERS-CoV; Human; Serology; Seroprevalence; Morocco.


#Seroprevalance of #antibodies specific for #SFTS virus and the discovery of #asymptomatic #infections in #Henan Province, #China (PLOS Negl Trop Dis., abstract)

[Source: PLOS Neglected Tropical Diseases, full page: (LINK). Abstract, edited.]


Seroprevalance of antibodies specific for severe fever with thrombocytopenia syndrome virus and the discovery of asymptomatic infections in Henan Province, China

Yanhua Du , Ningning Cheng , Yi Li, Haifeng Wang, Aiguo You, Jia Su, Yifei Nie, Hongxia Ma, Bianli Xu , Xueyong Huang


Published: November 25, 2019 / DOI: https://doi.org/10.1371/journal.pntd.0007242 / This is an uncorrected proof.




Severe fever with thrombocytopenia syndrome (SFTS) is a severe emerging disease caused by SFTS virus (SFTSV), and the geographical distribution of SFTS has been increasing throughout China in recent years. To assess SFTSV-specific antibody seroprevalence, a cross-sectional study was conducted for healthy people in high SFTS endemic areas of Henan province in 2016.


This study used a stratified random sampling method to select 14 natural villages as the investigation sites. From April to May 2016, participants completed a questionnaire survey and serum samples were collected. All serum samples were subjected to ELISA to detect SFTSV-specific IgM and IgG. All IgM-positive samples were further tested by real-time RT-PCR, and isolation of virus from serum was attempted. Any participant who was IgM-positive was followed up with a month later to confirm health status.


In total, 1463 healthy people participated in this study. The average seropositive rates for SFTSV-specific IgG and IgM were 10.46% (153/1463) and 0.82% (12/1463), respectively. IgM was detected in 12 individuals, and SFTSV RNA was detected in six of them. Virus was isolated from five of the six SFTSV RNA-positive individuals, and phylogenetic analyses revealed that all five isolates belonged to SFTSV group A. No IgM-positive participants exhibited any symptoms or other signs of illness at the one-month follow up.


This study identified a relatively high incidence of SFTSV-specific antibody seropositivity in healthy people in Xinyang city. Moreover, our data provide the first evidence for asymptomatic SFTSV infections, which may have significant implications for SFTS outbreak control.


Author summary

Severe fever with thrombocytopenia syndrome (SFTS) is a severe emerging infectious disease caused by SFTS virus (SFTSV) that was first discovered in rural areas of China. Henan province has had the largest number of SFTS cases in China every year since the disease was discovered, however, seropositivity for SFTSV-specific antibodies in healthy people in this region is still not clear. To address this issue, a cross-sectional survey was performed in high endemic areas from April to May 2016. The results showed that SFTSV seroprevalence was relatively high and possibly increasing. Notably, SFTSV RNA, as well as virus itself, was isolated from specimens obtained from healthy people. This study confirmed there are asymptomatic SFTSV infections in humans, and it is the first to report SFTSV isolation from healthy people.


Citation: Du Y, Cheng N, Li Y, Wang H, You A, Su J, et al. (2019) Seroprevalance of antibodies specific for severe fever with thrombocytopenia syndrome virus and the discovery of asymptomatic infections in Henan Province, China. PLoS Negl Trop Dis 13(11): e0007242. https://doi.org/10.1371/journal.pntd.0007242

Editor: Abdallah M. Samy, Faculty of Science, Ain Shams University (ASU), EGYPT

Received: February 10, 2019; Accepted: October 4, 2019; Published: November 25, 2019

Copyright: © 2019 Du et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Data Availability: All relevant data are within the manuscript and its Supporting Information files.

Funding: H.X.Y received grants from the National Natural Science Foundation of China (NO 81573204 https://isisn.nsfc.gov.cn/egrantweb/) and Henan provincial medical science and technology program (grant no.2018010029) .X.B.L. recieved a grant from the National Natural Science Foundation of China (NO 81773500 https://isisn.nsfc.gov.cn/egrantweb/).D.Y.H received a grant from Henan provincial medical science and technology program (grant no.2018020510). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

Competing interests: The authors have declared that no competing interests exist.

Keywords: Serology; Seroprevalence; SFTS; Henan; China.


#Serological prevalence of #avian #H9N2 #influenza virus in #dogs by hemagglutination inhibition assay in Kerman, southeast of #Iran (Vet Res Forum, abstract)

[Source: US National Library of Medicine, full page: (LINK). Abstract, edited.]

Vet Res Forum. 2019 Summer;10(3):249-253. doi: 10.30466/vrf.2018.87879.2140. Epub 2019 Sep 15.

Serological prevalence of avian H9N2 influenza virus in dogs by hemagglutination inhibition assay in Kerman, southeast of Iran.

Saberi M1, Tavakkoli H1, Najmaddini A2, Rezaei M1.

Author information: 1 Department of Clinical Sciences, Faculty of Veterinary Medicine, Shahid Bahonar University of Kerman, Kerman, Iran. 2 DVM Graduate,Faculty of Veterinary Medicine, Shahid Bahonar University of Kerman, Kerman, Iran.



Influenza is a highly contagious zoonotic disease in the world. Avian H9N2 influenza virus is a significant pandemic pathogen widely distributed throughout the world. Pet ownership has been documented as a risk factor for infection transmission to human. Considering major public health concern, the prevalence of antibodies against avian H9N2 influenza virus was evaluated in 170 serum samples of dogs by hemagglutination inhibition assay. This study is the first survey to assess the epidemiology of avian H9N2 influenza virus infection in dogs in Kerman, southeast of Iran. Out of 170 samples, 65 (38.23%) were positive for H9N2. Antibodies were higher in farm dogs that were kept with other animals and also in dogs were fed a raw diet. These findings emphasize the importance of close attention to these populations for control and prevention programs. It is important to reduce infection burden, especially in regions with widespread distribution of H9N2.

© 2019 Urmia University. All rights reserved.

KEYWORDS: Avian H9N2 influenza virus; Dog; Hemagglutination inhibition; Iran; Seroprevalence

PMID: 31737235 PMCID: PMC6828164 DOI: 10.30466/vrf.2018.87879.2140

Keywords: Avian Influenza; H9N2; Serology; Seroprevalence; Dogs; Iran.