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Shrestha A, Basnet S, Kc S. Subclinical hepatitis E virus genotype 1 infection: The concept of "dynamic human reservoir". World J Hepatol 2024; 16:506-510. [PMID: 38689746 PMCID: PMC11056895 DOI: 10.4254/wjh.v16.i4.506] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/28/2023] [Revised: 02/22/2024] [Accepted: 03/28/2024] [Indexed: 04/24/2024] Open
Abstract
Hepatitis E virus (HEV) is hyperendemic in South Asia and Africa accounting for half of total Global HEV burden. There are eight genotypes of HEV. Among them, the four common ones known to infect humans, genotypes 1 and 2 are prevalent in the developing world and genotypes 3 and 4 are causing challenge in the industrialized world. Asymptomatic HEV viremia in the general population, especially among blood donors, has been reported in the literature worldwide. The clinical implications related to this asymptomatic viremia are unclear and need further exploration. Detection of viremia due to HEV genotype 1 infection, apparently among healthy blood donors is also reported without much knowledge about its infection rate. Similarly, while HEV genotype 3 is known to be transmitted via blood transfusion in humans and has been subjected to screening in many European nations, instances of transmission have also been documented albeit without significant clinical consequences. Epidemiology of HEV genotype 1 in endemic areas often show waxing and waning pattern. Occasional sporadic occurrence of HEV infection interrupted by outbreaks have been frequently seen. In absence of known animal reservoir, where HEV exists in between outbreak is a mystery that needs further exploration. However, occurrence of asymptomatic HEV viremia due to HEV genotype 1 during epidemiologically quiescent period may explain that this phenomenon may act as a dynamic reservoir. Since HEV genotype 1 infection cannot cause chronicity, subclinical transient infection and transmission of virus might be the reason it sustains in interepidemic period. This might be the similar phenomenon with SARS COVID-19 corona virus infection which is circulating worldwide in distinct phases with peaks and plateaus despite vaccination against it. In view of existing evidence, we propose the concept of "Dynamic Human Reservoir." Quiescent subclinical infection of HEV without any clinical consequences and subsequent transmission may contribute to the existence of the virus in a community. The potential for transmitting HEV infection by asymptomatic HEV infected individuals by fecal shedding of virus has not been reported in literature. This missing link may be a key to Pandora's box in understanding epidemiology of HEV infection in genotype 1 predominant region.
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Affiliation(s)
- Ananta Shrestha
- Department of Hepatology, Alka Hospital, Kathmandu 44600, Nepal
| | - Suresh Basnet
- Department of Pulmonary and Critical Care Medicine, University of Maryland School of Medicine, Baltimore, MD 21201, United States
| | - Sudhamshu Kc
- Department of Hepatology, National Academy of Medical Sciences, Kathmandu 44600, Nepal.
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De Santis O, Bouscaren N, Flahault A. Asymptomatic dengue infection rate: A systematic literature review. Heliyon 2023; 9:e20069. [PMID: 37809992 PMCID: PMC10559824 DOI: 10.1016/j.heliyon.2023.e20069] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Revised: 09/04/2023] [Accepted: 09/11/2023] [Indexed: 10/10/2023] Open
Abstract
Objectives Dengue infection is spreading worldwide. The clinical spectrum is broad and includes asymptomatic infections. This review provides an overview of the different proportions of asymptomatic infections described in epidemiological studies according to definitions, study designs, and detection methods. Methods Medline and Embase databases were searched without restriction of date or language. Studies were included if they reported data on the incidence or prevalence of asymptomatic dengue infections. The data were summarized and classified according to the definitions of the term 'asymptomatic'. Results A total of 74 studies were included. The mean proportion of asymptomatic infections among dengue-infected persons was 54% in 50 included studies. The prevalence of dengue infections detected in healthy persons was 0.2% in 24 included studies. The term 'asymptomatic' has been used to refer to 'clinically undetectable infection', but also to 'undiagnosed infection' or 'mild infection'. Only 8% were clinically undetectable laboratory-confirmed dengue infections. Conclusion The proportion of asymptomatic dengue infections varied greatly. Studies proving data on clinically undetectable laboratory-confirmed dengue infections were very few, but provided consistent results of low proportions of asymptomatic infections. These data challenge the assumption that the majority of dengue cases are asymptomatic.
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Affiliation(s)
- Olga De Santis
- Institute of Global Health, Faculty of Medicine, University of Geneva, 1202 Geneva, Switzerland
- Direction de la recherche, de l'innovation et de la coopération internationale, CHU de La Réunion, 97410, Saint-Pierre, France
| | - Nicolas Bouscaren
- Service de Santé Publique et Soutien à la Recherche, Inserm CIC1410, CHU de La Réunion, 97410 Saint-Pierre, France
| | - Antoine Flahault
- Institute of Global Health, Faculty of Medicine, University of Geneva, 1202 Geneva, Switzerland
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Diaz J, Gusto C, McCoy K, Silvert C, Bala JA, Atibu J, Tshefu A, Mwandagalirwa M, Dinglasan RR. A mixed methods study assessing the adoption potential of a saliva-based malaria rapid test in the Democratic Republic of Congo. Malar J 2023; 22:180. [PMID: 37291561 DOI: 10.1186/s12936-023-04599-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Accepted: 05/20/2023] [Indexed: 06/10/2023] Open
Abstract
BACKGROUND The reliance on blood for thin and thick blood smear microscopy-using a relatively invasive procedure has presented challenges to the use of reliable diagnostic tests in non-clinical settings at the point-of-need (PON). To improve the capacity of non-blood-based rapid diagnostic tests to confirm subclinical infections, and thereby identify and quantify the human reservoir at the PON, a cross-sectoral collaboration between university researchers and commercial partners produced an innovative, non-invasive saliva-based RDT capable of identifying novel, non-hrp2/3 parasite biomarkers. While this new saliva-based malaria asymptomatic and asexual rapid test (SMAART-1) shows increased detection sensitivity and precision potential by identifying a new P. falciparum protein marker (PSSP17), appraising its utility in the field-particularly with respect to its adoption potential with children and adults in high risk, endemic regions-is necessary to warrant its continued development. METHODS The purpose of this study was to assess the acceptability and adoption potential of the SMAART-1 at select PON sites in the Kinshasa Province. Teachers, community health workers, nurses, and laboratory technicians participated in data collection at three distinct community sites in Kinshasa Province, Democratic Republic of the Congo. Three data collection methods were utilized in this mixed methods study to provide an overarching acceptability evaluation of the SMAART-1 at PON field sites: observation checklists of SMAART-1 implementation, focus group discussions, and surveys with local health care practitioners-particularly teachers and community health workers. RESULTS Findings indicate participants were interested in and supportive of the SMAART-1 protocol, with approximately 99% of the participants surveyed indicating that they either "agreed" or "strongly agreed" with the statement that they "would use the saliva-based malaria asymptomatic rapid test as part of a community malaria detection and treatment programme." Data also suggest that the protocol was broadly appealing for its testing sensitivity and ease of use. CONCLUSIONS The SMAART-1 protocol's clinically reliable results demonstrate a promising new level of sensitivity and precision for detecting parasite biomarkers. This study's mixed-methods assessment of the protocol's utility and adoption potential in the field, with a target user audience, advances its development and points to opportunities to formalize and expand evaluation efforts.
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Affiliation(s)
- John Diaz
- Gulf Coast Research and Education Center, University of Florida, 1200 N. Park Road, Plant City, FL, 33563, USA.
| | - Cody Gusto
- Department of Agricultural Education and Communication, University of Florida, Rolfs Hall, Gainesville, FL, 32611, USA
| | - Kaci McCoy
- Department of Infectious Diseases and Immunology, Emerging Pathogens Institute, College of Veterinary Medicine, University of Florida, 2055 Mowry Road, Rm 375, Gainesville, FL, 32611, USA
| | - Colby Silvert
- Department of Agricultural Education and Communication, University of Florida, Rolfs Hall, Gainesville, FL, 32611, USA
| | - Joseph A Bala
- Kinshasa School of Public Health, Kinshasa, Democratic Republic of the Congo
| | - Joseph Atibu
- Kinshasa School of Public Health, Kinshasa, Democratic Republic of the Congo
| | - Antoinette Tshefu
- Kinshasa School of Public Health, Kinshasa, Democratic Republic of the Congo
| | | | - Rhoel R Dinglasan
- Department of Infectious Diseases and Immunology, Emerging Pathogens Institute, College of Veterinary Medicine, University of Florida, 2055 Mowry Road, Rm 375, Gainesville, FL, 32611, USA
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Hanekom J, Lubisi BA, Leisewitz A, Guthrie A, Fosgate GT. The seroprevalence of African horse sickness virus, and risk factors to exposure, in domestic dogs in Tshwane, South Africa. Prev Vet Med 2023; 213:105868. [PMID: 36739812 DOI: 10.1016/j.prevetmed.2023.105868] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Revised: 01/25/2023] [Accepted: 01/29/2023] [Indexed: 02/04/2023]
Abstract
Dogs are the only non-equid species to develop the fatal form of African horse sickness (AHS). Research conducted in 2013 questioned the long-held belief that naturally occurring cases of AHS in dogs were contracted exclusively through the ingestion of contaminated horse meat. Culicoides midges, the vector of AHS virus (AHSV) for horses, have an aversion to dog blood meals and dogs were believed to be dead-end or incidental hosts. More recently, dog mortalities have occurred in the absence of horse meat consumption and vector transmission has been suspected. The current study is a retrospective serological survey of AHSV exposure in dogs from an endemic area. Dog sera collected from dogs (n = 366) living in the city of Tshwane, Gauteng Province, South Africa, were randomly selected from a biobank at a veterinary teaching hospital, corresponding to the years 2014-2019. The study used a laboratory in-house indirect recombinant VP7 antigen-based enzyme-linked immunosorbent assay (iELISA) with a test cut-off calculated from AHSV exposure-free dog sera (n = 32). Study AHSV seroprevalence was 6 % (22/366) with an estimated true prevalence of 4.1 % (95 % confidence interval (CI) = 1.3-8.1 %). Incidence was estimated for dogs with multiple serological results with seroconversion occurring at a rate of 2.3 seroconversions per 10 dog years at risk (95 % CI = 0.6-6.2). A subsection of the study sera was tested with AHSV viral neutralisation test (VN) (n = 42) for serotype determination. Antibodies to AHSV serotype 6 were most prevalent (90 %) in VN seropositive dogs (n = 20) with most dogs seemingly subclinically infected (>95 %). Seroprevalence descriptively varied by year and identified risk factors were annual rainfall > 754 mm (odds ratio (OR) = 5.76; 95 % CI = 2.22 - 14.95; p < 0.001), medium human population densities, 783-1663 people/km2 (OR = 7.14; 95 % CI = 1.39 - 36.73; p = 0.019) and 1664-2029 people/km2 (OR = 6.74; 95 % CI = 1.40 - 32.56; p = 0.018), and the month of March (OR = 5.12; 95 % CI = 1.41 - 18.61; p = 0.013). All identified risk factors were consistent with midge-borne transmission to dogs. The relatively high seroprevalence and seroconversion rates suggest frequent exposure of dogs to AHSV and indicates the need to investigate the role dogs might play in the overall epidemiology and transmission of AHSV.
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Affiliation(s)
- Josef Hanekom
- Companion Animal Clinical Studies, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, South Africa.
| | - Baratang A Lubisi
- Virology Section, Onderstepoort Veterinary Institute, Agricultural Research Centre, South Africa.
| | - Andrew Leisewitz
- Companion Animal Clinical Studies, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, South Africa; Department of Clinical Sciences, College of Veterinary Medicine, Auburn University, Auburn, USA.
| | - Alan Guthrie
- Equine Research Centre, Faculty of Veterinary Science University of Pretoria, Onderstepoort, South Africa.
| | - Geoffrey T Fosgate
- Production Animal Studies, Faculty of Veterinary Science University of Pretoria, Onderstepoort, South Africa.
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Hasegawa I, Nakano T, Koguchi H, Jinno N, Hirashima N, Nagashima S, Takahashi M, Murata K, Okamoto H. Subclinical hepatitis E virus (HEV) infection detected by nucleic acid amplification test on blood donation: short-term positivity for immunoglobulin G class of antibody against HEV. Clin J Gastroenterol 2022. [PMID: 35507275 DOI: 10.1007/s12328-022-01635-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Accepted: 04/11/2022] [Indexed: 10/18/2022]
Abstract
A case of subclinical hepatitis E virus (HEV) infection was detected by nucleic acid amplification test on blood donation. The patient was followed-up until day 220 after the blood donation but showed no symptoms throughout the observation period. Aspartate aminotransferase and alanine aminotransferase levels reached the maximum values on day 37 with a slight increase but remained in normal ranges from day 67 to 220. The quantity of HEV RNA at the initial examination on day 13 was 1.1 × 102 copies/mL, which increased to 2.8 × 103 copies/mL by day 37. It was not detected from day 67 to 220. Immunoglobulin G class antibody to HEV (anti-HEV IgG) was below the cut-off value until day 37 and exceeded the cut-off value to positive on day 67, accompanied by normalization of liver function and negative conversion of HEV RNA. Thereafter, the titer decreased gradually, falling below the cut-off value on day 163, and continuing negative until day 220. Although the persistent duration of anti-HEV IgG positive is believed to be generally long, it was within only 126 days for this subclinical case. Further investigation is needed to determine whether short-term positivity for anti-HEV IgG is typical in subclinical HEV infection.
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Kambayashi Y, Bannai H, Tsujimura K, Hirama A, Ohta M, Nemoto M. Outbreak of equine coronavirus infection among riding horses in Tokyo, Japan. Comp Immunol Microbiol Infect Dis 2021; 77:101668. [PMID: 34004508 DOI: 10.1016/j.cimid.2021.101668] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Revised: 04/28/2021] [Accepted: 05/06/2021] [Indexed: 11/20/2022]
Abstract
In 2020, an outbreak of equine coronavirus (ECoV) infection occurred among 41 horses at a riding stable in Tokyo, Japan. This stable had 16 Thoroughbreds and 25 horses of other breeds, including Andalusians, ponies and miniature horses. Fifteen horses (37 %) showed mild clinical signs such as fever, lethargy, anorexia and diarrhoea, and they recovered within 3 days of onset. A virus neutralization test showed that all 41 horses were infected with ECoV, signifying that 26 horses (63 %) were subclinical. The results suggest that subclinical horses played an important role as spreaders. A genome sequence analysis revealed that the lengths from genes p4.7 to p12.7 or NS2 in ECoV differed from those of ECoVs detected previously, suggesting that this outbreak was caused by a virus different from those that caused previous outbreaks among draughthorses in Japan. Among 30 horses that tested positive by real-time RT-PCR, ECoV shedding periods of non-Thoroughbreds were significantly longer than those of Thoroughbreds. The difference in shedding periods may indicate that some breeds excrete ECoV longer than other breeds and can contribute to the spread of ECoV.
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Nakajo K, Nishiura H. Transmissibility of asymptomatic COVID-19: Data from Japanese clusters. Int J Infect Dis 2021; 105:236-8. [PMID: 33618004 DOI: 10.1016/j.ijid.2021.02.065] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Revised: 02/15/2021] [Accepted: 02/16/2021] [Indexed: 12/25/2022] Open
Abstract
Background The epidemiological importance of asymptomatic individuals who would never develop illness, compared to those who eventually develop symptoms, has yet to be fully clarified. Methods The very first cluster data in Tokyo and Kanagawa (n = 36) were analyzed. Movement of all close contact was restricted for 14 days and they underwent laboratory testing with polymerase chain reaction. The reproduction numbers of symptomatic and asymptomatic cases were estimated. Results The reproduction number for symptomatic cases was estimated to be 1.2 (95% confidence interval (CI): 0.5–2.9). The relative infectiousness of asymptomatically infected cases was estimated to be 0.27 (95% CI: 0.03–0.81) of symptomatic cases. Conclusion The relative transmissibility of asymptomatic cases is limited. Observing clusters starting with symptomatic transmission might be sufficient for the control.
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Queiroz EA, Medeiros NI, Mattos RT, Pinto BF, Carvalho APM, Dutra WO, Félix-Lana FC, Correa-Oliveira R, Gomes JAS. CCL2 and IFN-γ serum levels as biomarkers for subclinical infection in household contacts of leprosy patients. Microb Pathog 2021; 150:104725. [PMID: 33400985 DOI: 10.1016/j.micpath.2020.104725] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Revised: 11/10/2020] [Accepted: 12/27/2020] [Indexed: 10/22/2022]
Abstract
Leprosy, also known as Hansen's disease, is a long-term infection by the bacteria Mycobacterium leprae, and actually still persists as a serious public health problem. The clinical parameters are used for diagnosis, however, some studies have indicated the selection of a set of biomarkers of subclinical infection, both serological and cellular, that allow the early diagnosis. Some cytokines and chemokines have been differentially expressed in index cases (paucibacillary and multibacillary patients) and household contacts (HHC), and may present a potential biomarker of M. leprae subclinical infection. Thus, the aim of this study was to analyze the variations in the profile of cytokines and chemokines, longitudinally, between index cases and their household contacts with a view to identifying possible biomarkers with differential expression, which may guide the early subclinical infection in household contacts. A longitudinal study was carried out between 2014 and 2015. The serum levels of the cytokines and chemokines were measured in all patient samples by CBA (Cytometric Bead Array). We observed a reduction of IL-4 and IL-17 expression of HHC group in the second evaluation (T1), as also a reduction of IL-17 in MB. We observed increased expression of IL-2 in PB patients as well. HHC, PB and MB showed a similar reduction profile of the chemokines CXCL8, CXCL9 and CXCL10 from T0 to T1. Interestingly, only serological levels of CCL2 are increased after a follow-up of HHC group, and this group, but not PB and MB patients, showed a significant association and a negative correlation between CCL2 and IFN-γ. The present study showed for the first time a similarity in the immunological scenario between HHC, PB and MB patients. In addition, this work highlights CCL2 chemokine in association with IFN-γ as possible biomarkers of subclinical infection of HHC, as also a parameter of early infection monitoring.
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Affiliation(s)
- Edson A Queiroz
- Escola de Enfermagem, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - Nayara I Medeiros
- Laboratório de Biologia das Interações Celulares, Departamento de Morfologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - Rafael T Mattos
- Laboratório de Biologia das Interações Celulares, Departamento de Morfologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - Bruna F Pinto
- Laboratório de Biologia das Interações Celulares, Departamento de Morfologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - Ana Paula M Carvalho
- Escola de Enfermagem, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - Walderez O Dutra
- Laboratório de Biologia das Interações Celulares, Departamento de Morfologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | | | - Rodrigo Correa-Oliveira
- Escola de Enfermagem, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil; Imunologia Celular e Molecular, Instituto René Rachou, Fundação Oswaldo Cruz - FIOCRUZ, Belo Horizonte, MG, Brazil
| | - Juliana A S Gomes
- Laboratório de Biologia das Interações Celulares, Departamento de Morfologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil.
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Mora-Díaz JC, Temeeyasen G, Magtoto R, Rauh R, Nelson W, Carrillo-Ávila JA, Zimmerman J, Piñeyro P, Giménez-Lirola L. Infection and immune response to porcine hemagglutinating encephalomyelitis virus in grower pigs. Vet Microbiol 2020; 253:108958. [PMID: 33387911 DOI: 10.1016/j.vetmic.2020.108958] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Accepted: 12/13/2020] [Indexed: 11/28/2022]
Abstract
Porcine hemagglutinating encephalomyelitis virus (PHEV) is the cause of acute outbreaks of vomiting and wasting disease and/or encephalomyelitis in neonatal pigs, with naïve herds particularly vulnerable to clinical episodes. PHEV infections in older pigs are generally considered to be subclinical, but are poorly characterized in the refereed literature. In this study, twelve 7-week-old pigs were oronasally inoculated with 0.5 mL (1:128 HA titer) PHEV (Mengeling strain) and then followed through 42 days post inoculation (dpi). Fecal and oral fluid specimens were collected daily to evaluate viral shedding. Serum samples were tested for viremia, isotype-specific antibody responses, cytokine, and chemokine responses. Peripheral blood mononuclear cells were isolated to evaluate phenotype changes in immune cell subpopulations. No clinical signs were observed in PHEV inoculated pigs, but virus was detected in oral fluid (1-28 dpi) and feces (1-10 dpi). No viremia was detected, but a significant IFN-α response was observed in serum at 3 dpi, followed by the detection of IgM (dpi 7), and IgA/IgG (dpi 10). Flow cytometry revealed a one-off increase in cytotoxic T cells at 21 dpi. This study demonstrated that exposure of grower pigs to PHEV results in subclinical infection characterized by active viral replication and shedding followed by an active humoral and cell-mediated immune response that attenuates the course of the infection and results in viral clearance.
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Affiliation(s)
- Juan Carlos Mora-Díaz
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA, USA
| | - Gun Temeeyasen
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA, USA
| | - Ronaldo Magtoto
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA, USA
| | | | | | | | - Jeffrey Zimmerman
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA, USA
| | - Pablo Piñeyro
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA, USA
| | - Luis Giménez-Lirola
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA, USA.
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Matsuba I, Hatori N, Koido N, Watanabe Y, Ebara F, Matsuzawa Y, Nishikawa T, Kunishima T, Degawa H, Nishikawa M, Ono Y, Kanamori A. Survey of the current status of subclinical coronavirus disease 2019 (COVID-19). J Infect Chemother 2020; 26:1294-1300. [PMID: 32958395 PMCID: PMC7474902 DOI: 10.1016/j.jiac.2020.09.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Revised: 08/14/2020] [Accepted: 09/02/2020] [Indexed: 12/28/2022]
Abstract
OBJECTIVES We investigated relationships between subclinical COVID-19 (coronavirus disease 2019) and background factors. METHODS We determined SARS-CoV-2 antibody (IgG) prevalence in 1603 patients, doctors, and nurses in 65 medical institutions in Kanagawa Prefecture, Japan and investigated their background factors. Antibodies (IgG) against SARS-CoV-2 were analyzed by Immunochromatographic test. RESULTS The 39 subjects (2.4%) were found to be IgG antibody-positive: 29 in the patient group (2.9%), 10 in the doctor/nurse group (2.0%), and 0 in the control group. After adjustment for age, sex, and the antibody prevalence in the control group, antibody prevalence was 2.7% in the patient group and 2.1% in the doctor/nurse group. There was no significant difference between the antibody-positive subjects and the antibody-negative subjects in any background factors investigated including overseas travel, contact with overseas travelers, presence/absence of infected individuals in the living area, use of trains 5 times a week or more, BCG vaccination, and use of ACE inhibitor and ARB. CONCLUSIONS Antibody prevalence in the present survey at medical institution is higher than that in Tokyo and in Osaka measured by the government suggesting that subclinical infections are occurring more frequently than expected. No background factor that influenced antibody-positive status due to subclinical infection was identified.
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Tsou HH, Cheng YC, Yuan HY, Hsu YT, Wu HY, Lee FJ, Hsiung CA, Chen WJ, Sytwu HK, Wu SI, Shih SM, Wen TH, Kuo SC. The effect of preventing subclinical transmission on the containment of COVID-19: Mathematical modeling and experience in Taiwan. Contemp Clin Trials 2020; 96:106101. [PMID: 32771432 DOI: 10.1016/j.cct.2020.106101] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Revised: 07/23/2020] [Accepted: 08/02/2020] [Indexed: 11/22/2022]
Abstract
The control strategies preventing subclinical transmission differed among countries. A stochastic transmission model was used to assess the potential effectiveness of control strategies at controlling the COVID-19 outbreak. Three strategies included lack of prevention of subclinical transmission (Strategy A), partial prevention using testing with different accuracy (Strategy B) and complete prevention by isolating all at-risk people (Strategy C, Taiwan policy). The high probability of containing COVID-19 in Strategy C is observed in different scenario, had varied in the number of initial cases (5, 20, and 40), the reproduction number (1.5, 2, 2.5, and 3.5), the proportion of at-risk people being investigated (40%, 60%, 80%, to 90%), the delay from symptom onset to isolation (long and short), and the proportion of transmission that occurred before symptom onset (<1%, 15%, and 30%). Strategy C achieved probability of 80% under advantageous scenario, such as low number of initial cases and high coverage of epidemiological investigation but Strategy B and C rarely achieved that of 60%. Considering the unsatisfactory accuracy of current testing and insufficient resources, isolation of all at-risk people, as adopted in Taiwan, could be an effective alternative.
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Rathod S, Ahmed S, Vanstone R, Fatoye T, Desautels D, Koul R. Working in the dark: Interaction with a sub clinical COVID-19 subject and lessons learned. Eur J Cancer 2020; 135:101-2. [PMID: 32563013 DOI: 10.1016/j.ejca.2020.05.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Accepted: 05/05/2020] [Indexed: 11/24/2022]
Abstract
Subclinical COVID-19 subjects pose a significant challenge. We present a very close clinical interaction with a subclinical COVID-19 subject that met the “standard screening criteria” and is unique in several ways. Learning from our experience, we suggest close attention should be paid to any unexpected findings such as groundglass opacity on CT as it could help early identification of subclinical COVID-19 infection.
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Gill ON, Spencer Y, Richard-Loendt A, Kelly C, Brown D, Sinka K, Andrews N, Dabaghian R, Simmons M, Edwards P, Bellerby P, Everest DJ, McCall M, McCardle LM, Linehan J, Mead S, Hilton DA, Ironside JW, Brandner S. Prevalence in Britain of abnormal prion protein in human appendices before and after exposure to the cattle BSE epizootic. Acta Neuropathol 2020; 139:965-976. [PMID: 32232565 PMCID: PMC7244468 DOI: 10.1007/s00401-020-02153-7] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Revised: 03/23/2020] [Accepted: 03/23/2020] [Indexed: 12/20/2022]
Abstract
Widespread dietary exposure of the population of Britain to bovine spongiform encephalopathy (BSE) prions in the 1980s and 1990s led to the emergence of variant Creutzfeldt-Jakob Disease (vCJD) in humans. Two previous appendectomy sample surveys (Appendix-1 and -2) estimated the prevalence of abnormal prion protein (PrP) in the British population exposed to BSE to be 237 per million and 493 per million, respectively. The Appendix-3 survey was recommended to measure the prevalence of abnormal PrP in population groups thought to have been unexposed to BSE. Immunohistochemistry for abnormal PrP was performed on 29,516 samples from appendices removed between 1962 and 1979 from persons born between 1891 through 1965, and from those born after 1996 that had been operated on from 2000 through 2014. Seven appendices were positive for abnormal PrP, of which two were from the pre-BSE-exposure era and five from the post BSE-exposure period. None of the seven positive samples were from appendices removed before 1977, or in patients born after 2000 and none came from individuals diagnosed with vCJD. There was no statistical difference in the prevalence of abnormal PrP across birth and exposure cohorts. Two interpretations are possible. Either there is a low background prevalence of abnormal PrP in human lymphoid tissues that may not progress to vCJD. Alternatively, all positive specimens are attributable to BSE exposure, a finding that would necessitate human exposure having begun in the late 1970s and continuing through the late 1990s.
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Affiliation(s)
- O Noel Gill
- STI and HIV Department and CJD Section' Blood Safety, Hepatitis, STIs and HIV Division Public Health England National Infection Service, 61 Colindale Avenue, London, NW9 5EQ, United Kingdom
| | - Yvonne Spencer
- Pathology and Animal Sciences Department Science Directorate Animal and Plant Health Agency Addlestone, Surrey, KT15 3NB, United Kingdom
| | - Angela Richard-Loendt
- Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology Queen Square, London, WC1N 3BG, United Kingdom
- Division of Neuropathology, The National Hospital for Neurology and Neurosurgery, University College London Hospitals NHS Foundation Trust Queen Square, London, WC1N 3BG, United Kingdom
| | - Carole Kelly
- STI and HIV Department and CJD Section' Blood Safety, Hepatitis, STIs and HIV Division Public Health England National Infection Service, 61 Colindale Avenue, London, NW9 5EQ, United Kingdom
| | - David Brown
- Virus Reference Department Public, Health England National Infection Service, 61 Colindale Avenue, London, NW9 5HT, United Kingdom
| | - Katy Sinka
- STI and HIV Department and CJD Section' Blood Safety, Hepatitis, STIs and HIV Division Public Health England National Infection Service, 61 Colindale Avenue, London, NW9 5EQ, United Kingdom
| | - Nick Andrews
- STI and HIV Department and CJD Section' Blood Safety, Hepatitis, STIs and HIV Division Public Health England National Infection Service, 61 Colindale Avenue, London, NW9 5EQ, United Kingdom
| | - Reza Dabaghian
- Virus Reference Department Public, Health England National Infection Service, 61 Colindale Avenue, London, NW9 5HT, United Kingdom
| | - Marion Simmons
- Pathology and Animal Sciences Department Science Directorate Animal and Plant Health Agency Addlestone, Surrey, KT15 3NB, United Kingdom
| | - Philip Edwards
- Department of Cellular and Anatomical, Pathology University Hospitals Plymouth, Plymouth, PL6 8DH, United Kingdom
| | - Peter Bellerby
- Pathology and Animal Sciences Department Science Directorate Animal and Plant Health Agency Addlestone, Surrey, KT15 3NB, United Kingdom
| | - David J Everest
- Pathology and Animal Sciences Department Science Directorate Animal and Plant Health Agency Addlestone, Surrey, KT15 3NB, United Kingdom
| | - Mark McCall
- STI and HIV Department and CJD Section' Blood Safety, Hepatitis, STIs and HIV Division Public Health England National Infection Service, 61 Colindale Avenue, London, NW9 5EQ, United Kingdom
| | - Linda M McCardle
- National Creutzfeldt-Jakob Disease Research and Surveillance Unit Centre for Clinical Brain Sciences, University of Edinburgh, Western General Hospital, Edinburgh, EH4 2XU, United Kingdom
| | - Jacqueline Linehan
- MRC Prion Unit at UCL, UCL Institute of Prion Diseases Courtauld Building, 33 Cleveland Street, London, W1W 7FF, United Kingdom
| | - Simon Mead
- MRC Prion Unit at UCL, UCL Institute of Prion Diseases Courtauld Building, 33 Cleveland Street, London, W1W 7FF, United Kingdom
| | - David A Hilton
- Department of Cellular and Anatomical, Pathology University Hospitals Plymouth, Plymouth, PL6 8DH, United Kingdom
| | - James W Ironside
- National Creutzfeldt-Jakob Disease Research and Surveillance Unit Centre for Clinical Brain Sciences, University of Edinburgh, Western General Hospital, Edinburgh, EH4 2XU, United Kingdom
| | - Sebastian Brandner
- Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology Queen Square, London, WC1N 3BG, United Kingdom.
- Division of Neuropathology, The National Hospital for Neurology and Neurosurgery, University College London Hospitals NHS Foundation Trust Queen Square, London, WC1N 3BG, United Kingdom.
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Queiroz EA, Medeiros NI, Mattos RT, Carvalho APM, Rodrigues-Alves ML, Dutra WO, Félix-Lana FC, Gomes JAS, Correa-Oliveira R. Immunological biomarkers of subclinical infection in household contacts of leprosy patients. Immunobiology 2019; 224:518-525. [PMID: 31109749 DOI: 10.1016/j.imbio.2019.05.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Revised: 04/21/2019] [Accepted: 05/07/2019] [Indexed: 10/26/2022]
Abstract
Hansen's disease (or leprosy) still persists as a serious public health issue. Its diagnosis is based primarily on the detection of clinical signs that are characteristic of the disease. Studies have pointed to the selection of a set of serological and cellular biomarkers of subclinical infection that result in an efficient diagnosis. The aim of this study was compare index cases and their household contacts to identify differentially expressed biomarkers of immune response in leprosy that could provide reliable evidence of subclinical infection in household contacts. The study population consisted of index cases with multibacillary form (IC, n = 13) and their household contacts (HC, n = 14). Serum cytokines and chemokines were quantified using the cytometric beads array (CBA) system. The humoral response was assessed by ELISA test. Flow cytometry was used to characterize the cellular immune response. Monocyte and CD4 + T lymphocytes frequency was significantly higher in IC. Both CD4+ and CD8 + T lymphocytes had a reduced CD25 expression in HC. The immunoglobulin (Ig)M profile anti- NDO-HSA, LID-1, and NDOLID antigens was significantly higher in IC. This study points to the monocyte and CD4+ lymphocyte frequency, as well as specific IgM profile, as predictors of subclinical infection in the household contacts.
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Affiliation(s)
- Edson A Queiroz
- Escola de Enfermagem, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil.
| | - Nayara I Medeiros
- Imunologia Celular e Molecular, Instituto René Rachou, Fundação Oswaldo Cruz - FIOCRUZ, Belo Horizonte, MG, Brazil; Laboratório de Biologia das Interações Celulares, Departamento de Morfologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil.
| | - Rafael T Mattos
- Laboratório de Biologia das Interações Celulares, Departamento de Morfologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil.
| | - Ana Paula M Carvalho
- Escola de Enfermagem, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil.
| | - Marina L Rodrigues-Alves
- Laboratório de Biologia das Interações Celulares, Departamento de Morfologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil.
| | - Walderez O Dutra
- Laboratório de Biologia das Interações Celulares, Departamento de Morfologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil.
| | | | - Juliana A S Gomes
- Laboratório de Biologia das Interações Celulares, Departamento de Morfologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil.
| | - Rodrigo Correa-Oliveira
- Escola de Enfermagem, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil; Imunologia Celular e Molecular, Instituto René Rachou, Fundação Oswaldo Cruz - FIOCRUZ, Belo Horizonte, MG, Brazil.
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Abstract
During early 2017, we conducted a seroepidemiologic investigation for tickborne encephalitis virus among 291 Japan Self-Defense Forces members in Hokkaido. Two (0.7%) tested positive. Neither had clinically apparent symptoms after removing ticks.
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Dhanoa A, Hassan SS, Jahan NK, Reidpath DD, Fatt QK, Ahmad MP, Meng CY, Ming LW, Zain AZ, Phipps ME, Othman I, Rabu AB, Sirajudeen R, Fatan AABA, Ghafar FA, Ahmad HB, Allotey P. Seroprevalence of dengue among healthy adults in a rural community in Southern Malaysia: a pilot study. Infect Dis Poverty 2018; 7:1. [PMID: 29335021 PMCID: PMC5769361 DOI: 10.1186/s40249-017-0384-1] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2017] [Accepted: 12/27/2017] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND The frequency and magnitude of dengue epidemics continue to increase exponentially in Malaysia, with a shift in the age range predominance toward adults and an expansion to rural areas. Despite this, information pertaining to the extent of transmission of dengue virus (DENV) in the rural community is lacking. This community-based pilot study was conducted to establish DENV seroprevalence amongst healthy adults in a rural district in Southern Malaysia, and to identify influencing factors. METHODS In this study undertaken between April and May 2015, a total of 277 adult participants were recruited from households across three localities in the Sungai Segamat subdistrict in Segamat district. Sera were tested for immunoglobulin G (IgG) (Panbio® Dengue Indirect IgG ELISA/high-titer capture) and immunoglobulin M (IgM) (Panbio®) antibodies. The plaque reduction neutralization test (PRNT) was conducted on random samples of IgG-positive sera for further confirmation. Medical history and a recall of previous history of dengue were collected through interviews, whereas sociodemographic information was obtained from an existing database. RESULTS The overall seroprevalence for DENV infection was 86.6% (240/277) (95% CI: 83-91%). Serological evidence of recent infection (IgM/high-titer capture IgG) was noted in 11.2% (31/277) of participants, whereas there was evidence of past infection in 75.5% (209/277) of participants (indirect IgG minus recent infections). The PRNT assay showed that the detected antibodies were indeed specific to DENV. The multivariate analysis showed that the older age group was significantly associated with past DENV infections. Seropositivity increased with age; 48.5% in the age group of <25 years to more than 85% in age group of >45 years (P < 0.001). No associations with occupation, study site, housing type, comorbidity, educational level, and marital status were observed, although the latter two were statistically significant in the univariate analysis. None of the studied factors were significantly associated with recent DENV infections in the multivariate analysis, although there was a pattern suggestive of recent outbreak in two study sites populated predominately by Chinese people. The majority of infections did not give rise to recognizable disease (either asymptomatic or nonspecific symptoms) as only 12.9% of participants (31/240) recalled having dengue in the past. CONCLUSIONS The predominantly rural community under study had a very high previous exposure to dengue. The finding of a high proportion of unreported cases possibly due to subclinical infections underscores the need for enhanced surveillance and control methods. This finding also has implications for measuring disease burden, understanding transmission dynamics, and hypothesizing effects on DENV vaccine efficacy and uptake.
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Affiliation(s)
- Amreeta Dhanoa
- Jeffrey Cheah School of Medicine and Health Sciences, Monash University Malaysia, Jalan Lagoon Selatan, Bandar Sunway, 47500 Petaling Jaya, Malaysia
- Infection and Immunity Cluster, Tropical Medicine and Biology Platform, Monash University Malaysia, Jalan Lagoon Selatan, Bandar Sunway, 47500 Petaling Jaya, Malaysia
| | - Sharifah Syed Hassan
- Jeffrey Cheah School of Medicine and Health Sciences, Monash University Malaysia, Jalan Lagoon Selatan, Bandar Sunway, 47500 Petaling Jaya, Malaysia
- Infection and Immunity Cluster, Tropical Medicine and Biology Platform, Monash University Malaysia, Jalan Lagoon Selatan, Bandar Sunway, 47500 Petaling Jaya, Malaysia
| | - Nowrozy Kamar Jahan
- Jeffrey Cheah School of Medicine and Health Sciences, Monash University Malaysia, Jalan Lagoon Selatan, Bandar Sunway, 47500 Petaling Jaya, Malaysia
- South East Asia Community Observatory (SEACO), 146 Jalan Sia Her Yam, Suite 601–606, Wisma Centrepoint, 85000 Segamat, Johor Darul Takzim Malaysia
| | - Daniel D. Reidpath
- Jeffrey Cheah School of Medicine and Health Sciences, Monash University Malaysia, Jalan Lagoon Selatan, Bandar Sunway, 47500 Petaling Jaya, Malaysia
- South East Asia Community Observatory (SEACO), 146 Jalan Sia Her Yam, Suite 601–606, Wisma Centrepoint, 85000 Segamat, Johor Darul Takzim Malaysia
| | - Quek Kia Fatt
- Jeffrey Cheah School of Medicine and Health Sciences, Monash University Malaysia, Jalan Lagoon Selatan, Bandar Sunway, 47500 Petaling Jaya, Malaysia
- Infection and Immunity Cluster, Tropical Medicine and Biology Platform, Monash University Malaysia, Jalan Lagoon Selatan, Bandar Sunway, 47500 Petaling Jaya, Malaysia
| | - Mohtar Pungut Ahmad
- Segamat District Public Health Office, Ministry of Health Malaysia, Peti Surat 102, Jalan Gudang Ubat, Kampung Gubah, 85000 Segamat, Johor Darul Takzim Malaysia
| | - Cheong Yuet Meng
- Jeffrey Cheah School of Medicine and Health Sciences, Monash University Malaysia, Jalan Lagoon Selatan, Bandar Sunway, 47500 Petaling Jaya, Malaysia
- Infection and Immunity Cluster, Tropical Medicine and Biology Platform, Monash University Malaysia, Jalan Lagoon Selatan, Bandar Sunway, 47500 Petaling Jaya, Malaysia
| | - Lau Wee Ming
- Jeffrey Cheah School of Medicine and Health Sciences, Monash University Malaysia, Jalan Lagoon Selatan, Bandar Sunway, 47500 Petaling Jaya, Malaysia
- Infection and Immunity Cluster, Tropical Medicine and Biology Platform, Monash University Malaysia, Jalan Lagoon Selatan, Bandar Sunway, 47500 Petaling Jaya, Malaysia
| | - Anuar Zaini Zain
- Jeffrey Cheah School of Medicine and Health Sciences, Monash University Malaysia, Jalan Lagoon Selatan, Bandar Sunway, 47500 Petaling Jaya, Malaysia
- Infection and Immunity Cluster, Tropical Medicine and Biology Platform, Monash University Malaysia, Jalan Lagoon Selatan, Bandar Sunway, 47500 Petaling Jaya, Malaysia
| | - Maude Elvira Phipps
- Jeffrey Cheah School of Medicine and Health Sciences, Monash University Malaysia, Jalan Lagoon Selatan, Bandar Sunway, 47500 Petaling Jaya, Malaysia
- Infection and Immunity Cluster, Tropical Medicine and Biology Platform, Monash University Malaysia, Jalan Lagoon Selatan, Bandar Sunway, 47500 Petaling Jaya, Malaysia
| | - Iekhsan Othman
- Jeffrey Cheah School of Medicine and Health Sciences, Monash University Malaysia, Jalan Lagoon Selatan, Bandar Sunway, 47500 Petaling Jaya, Malaysia
- Infection and Immunity Cluster, Tropical Medicine and Biology Platform, Monash University Malaysia, Jalan Lagoon Selatan, Bandar Sunway, 47500 Petaling Jaya, Malaysia
| | - Aman Bin Rabu
- Hospital Segamat, Ministry of Health Malaysia, KM 6, Jalan Genuang, 85000 Segamat, Johor Darul Takzim Malaysia
| | - Rowther Sirajudeen
- Hospital Segamat, Ministry of Health Malaysia, KM 6, Jalan Genuang, 85000 Segamat, Johor Darul Takzim Malaysia
| | | | - Faidzal Adlee Ghafar
- Hospital Segamat, Ministry of Health Malaysia, KM 6, Jalan Genuang, 85000 Segamat, Johor Darul Takzim Malaysia
| | | | - Pascale Allotey
- Jeffrey Cheah School of Medicine and Health Sciences, Monash University Malaysia, Jalan Lagoon Selatan, Bandar Sunway, 47500 Petaling Jaya, Malaysia
- South East Asia Community Observatory (SEACO), 146 Jalan Sia Her Yam, Suite 601–606, Wisma Centrepoint, 85000 Segamat, Johor Darul Takzim Malaysia
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Albuquerque A, Campino L, Cardoso L, Cortes S. Evaluation of four molecular methods to detect Leishmania infection in dogs. Parasit Vectors 2017; 10:57. [PMID: 28285595 PMCID: PMC5346836 DOI: 10.1186/s13071-017-2002-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2016] [Accepted: 01/25/2017] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Canine leishmaniasis, a zoonotic disease caused by Leishmania infantum vectored by phlebotomine sand flies, is considered a relevant veterinary and public health problem in various countries, namely in the Mediterranean basin and Brazil, where dogs are considered the main reservoir hosts. Not only diseased dogs but also those subclinically infected play a relevant role in the transmission of L. infantum to vectors; therefore, early diagnosis is essential, under both a clinical and an epidemiological perspective. Molecular tools can be a more accurate and sensitive approach for diagnosis, with a wide range of protocols currently in use. The aim of the present report was to compare four PCR based protocols for the diagnosis of canine Leishmania infection in a cohort of dogs from the Douro region, Portugal. RESULTS A total of 229 bone marrow samples were collected from dogs living in the Douro region, an endemic region for leishmaniasis. Four PCR protocols were evaluated for Leishmania DNA detection in canine samples, three single (ITS1-PCR, MC-PCR and Uni21/Lmj4-PCR) and one nested (nested SSU rRNA-PCR). Two of the protocols were based on nuclear targets and the other two on kinetoplastid targets. The higher overall percentage of infected dogs was detected with the nested SSU rRNA-PCR (37.6%), which also was able to detect Leishmania DNA in a higher number of samples from apparently healthy dogs (25.3%). The ITS1-PCR presented the lowest level of Leishmania detection. CONCLUSIONS Nested SSU rRNA-PCR is an appropriate method to detect Leishmania infection in dogs. Accurate and early diagnosis in clinically suspect as well as apparently healthy dogs is essential, in order to treat and protect animals and public health and contribute to the control and awareness of the disease.
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Affiliation(s)
- Andreia Albuquerque
- Global Health and Tropical Medicine, GHTM, Instituto de Higiene e Medicina Tropical, IHMT, Universidade Nova de Lisboa, UNL, Rua da Junqueira 100, 1349-008, Lisbon, Portugal.,Present address: Institut für Zelluläre Chemie, Medizinische Hochschule Hannover, Carl-Neuberg-Str. 1, 30625, Hannover, Germany
| | - Lenea Campino
- Global Health and Tropical Medicine, GHTM, Instituto de Higiene e Medicina Tropical, IHMT, Universidade Nova de Lisboa, UNL, Rua da Junqueira 100, 1349-008, Lisbon, Portugal.,Department of Biomedical Sciences and Medicine, Campus Gambelas, Universidade de Faro, Faro, Portugal
| | - Luís Cardoso
- Department of Veterinary Sciences, School of Agrarian and Veterinary Sciences, University of Trás-os-Montes e Alto Douro, UTAD, Quinta de Prados, 5000-801, Vila Real, Portugal.
| | - Sofia Cortes
- Global Health and Tropical Medicine, GHTM, Instituto de Higiene e Medicina Tropical, IHMT, Universidade Nova de Lisboa, UNL, Rua da Junqueira 100, 1349-008, Lisbon, Portugal
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Loria-Cervera EN, Sosa-Bibiano EI, Van Wynsberghe NR, Saldarriaga OA, Melby PC, Andrade-Narvaez FJ. Cytokine mRNA expression in Peromyscus yucatanicus (Rodentia: Cricetidae) infected by Leishmania (Leishmania) mexicana. Cytokine 2016; 83:176-181. [PMID: 27155064 DOI: 10.1016/j.cyto.2016.04.016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Revised: 04/26/2016] [Accepted: 04/27/2016] [Indexed: 02/04/2023]
Abstract
Peromyscus yucatanicus, the main reservoir of Leishmania (Leishmania) mexicana in the Yucatan peninsula of Mexico, reproduces clinical and histological pictures of LCL in human as well as subclinical infection. Thus, we used this rodent as a novel experimental model. In this work, we analyzed cytokine mRNA expression in P. yucatanicus infected with L. (L.) mexicana. Animals were inoculated with either 2.5×10(6) or 1×10(2) promastigotes and cytokine expressions were analyzed by real-time RT-PCR in skin at 4 and 12weeks post-infection (wpi). Independently of the parasite inoculum none of the infected rodents had clinical signs of LCL at 4wpi and all expressed high IFN-γ mRNA. All P. yucatanicus inoculated with 2.5×10(6) promastigotes developed signs of LCL at 12wpi while the mice inoculated with 1×10(2) remained subclinical. At that time, both IFN-γ and IL-10 were expressed in P. yucatanicus with clinical and subclinical infections. Expressions of TNF-α and IL-4 were significantly higher in clinical animals (2.5×10(6)) compared with subclinical ones (1×10(2)). High TGF-β expression was observed in P. yucatanicus with clinical signs when compared with healthy animals. Results suggested that the clinical course of L. (L.) mexicana infection in P. yucatanicus was associated with a specific local pattern of cytokine production at 12wpi.
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Affiliation(s)
- Elsy Nalleli Loria-Cervera
- Universidad Autonoma de Yucatan, Centro de Investigaciones Regionales "Dr. Hideyo Noguchi", Laboratorio de Inmunologia, Ave. Itzaes No. 490 x 59-A, Merida, Yucatan, Mexico.
| | - Erika Ivett Sosa-Bibiano
- Universidad Autonoma de Yucatan, Centro de Investigaciones Regionales "Dr. Hideyo Noguchi", Laboratorio de Inmunologia, Ave. Itzaes No. 490 x 59-A, Merida, Yucatan, Mexico.
| | - Nicole Raymonde Van Wynsberghe
- Universidad Autonoma de Yucatan, Centro de Investigaciones Regionales "Dr. Hideyo Noguchi", Laboratorio de Inmunologia, Ave. Itzaes No. 490 x 59-A, Merida, Yucatan, Mexico.
| | - Omar Abdul Saldarriaga
- Center for Tropical Diseases, Department of Internal Medicine, University of Texas Medical Branch, 4.304 Marvin Graves Building, 301 University Boulevard, Galveston, TX, USA.
| | - Peter C Melby
- Center for Tropical Diseases, Department of Internal Medicine, University of Texas Medical Branch, 4.304 Marvin Graves Building, 301 University Boulevard, Galveston, TX, USA.
| | - Fernando Jose Andrade-Narvaez
- Universidad Autonoma de Yucatan, Centro de Investigaciones Regionales "Dr. Hideyo Noguchi", Laboratorio de Inmunologia, Ave. Itzaes No. 490 x 59-A, Merida, Yucatan, Mexico.
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Gerber PF, Trampel DW, Willinghan EM, Billam P, Meng XJ, Opriessnig T. Subclinical avian hepatitis E virus infection in layer flocks in the United States. Vet J 2015; 206:304-11. [PMID: 26564555 DOI: 10.1016/j.tvjl.2015.10.014] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2015] [Revised: 09/17/2015] [Accepted: 10/04/2015] [Indexed: 12/13/2022]
Abstract
The objective of this study was to determine patterns of avian HEV infection in naturally infected chicken farms. A total of 310 serum samples and 62 pooled fecal samples were collected from 62 chicken flocks on seven commercial in-line egg farms in the Midwestern United States and tested for avian HEV circulation. Serum samples were tested for the presence of anti-avian HEV IgY antibodies by a fluorescent microbead immunoassay (FMIA) which was developed for this study. The FMIA was validated using archived samples of chickens with known exposure (n = 96) and compared to the results obtained with an enzyme-linked immunosorbent assay (ELISA) based on the same capture antigen. There was an overall substantial agreement between the two assays (κ = 0.63) with earlier detection of positive chickens by the FMIA (P = 0.04). On the seven farms investigated, the overall prevalence of anti-avian HEV IgY antibodies in serum samples from commercial chickens was 44.8% (20-82% per farm). Fecal samples were tested for avian HEV RNA by a nested reverse-transcriptase PCR. The overall detection rate of avian HEV RNA in fecal samples was 62.9% (0-100% per farm). Sequencing analyses of partial helicase and capsid genes showed that different avian HEV genotype 2 strains were circulating within a farm. However, no correlation was found between avian HEV RNA detection and egg production, egg weight or mortality. In conclusion, avian HEV infection is widespread among clinically healthy laying hens in the United States.
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Khuntirat B, Love CS, Buddhari D, Heil GL, Gibbons RV, Rothman AL, Srikiatkhachorn A, Gray GC, Yoon IK. Absence of neutralizing antibodies against influenza A/H5N1 virus among children in Kamphaeng Phet, Thailand. J Clin Virol 2015. [PMID: 26209384 DOI: 10.1016/j.jcv.2015.05.025] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
BACKGROUND Influenza A/H5N1 actively circulated in Kamphaeng Phet (KPP), Thailand from 2004 to 2006. A prospective longitudinal cohort study of influenza virus infection in 800 adults conducted during 2008-2010 in KPP suggested that subclinical or mild H5N1 infections had occurred among this adult cohort. However, this study was conducted after the peak of H5N1 activity in KPP. Coincidentally, banked serum samples were available from a prospective longitudinal cohort study of primary school children who had undergone active surveillance for febrile illnesses from 2004 to 2007 and lived in the same district of KPP as the adult cohort. OBJECTIVES We sought to investigate whether subclinical or mild H5N1 infections had occurred among KPP residents during the peak of H5N1 activity from 2004 to 2006. STUDY DESIGN H5N1 microneutralization (MN) assay was performed on banked serum samples from a prospective longitudinal cohort study of primary school children who had undergone active surveillance for febrile illnesses in KPP. Annual blood samples collected from 2004 to 2006 from 251 children were selected based on the criteria that they lived in villages with documented H5N1 infection. RESULT No H5N1 neutralizing antibodies were detected in 753 annual blood samples from 251 children. CONCLUSION During 2004-2006, very few subclinical or mild H5N1 infections occurred in KPP. Elevated H5N1 MN titers found in the adult cohort in 2008 were likely due to cross-reactivity from other influenza virus subtypes highlighting the complexities in interpreting influenza serological data.
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Affiliation(s)
- Benjawan Khuntirat
- Department of Virology, Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand.
| | | | - Darunee Buddhari
- Department of Virology, Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand
| | - Gary L Heil
- College of Public Health and Health Professions and Emerging Pathogens Institute, University of Florida, Gainesville, FL, USA
| | - Robert V Gibbons
- Department of Virology, Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand
| | - Alan L Rothman
- Institute for Immunology and Informatics, University of Rhode Island, Providence, Rhode Island, USA
| | - Anon Srikiatkhachorn
- Division of Infectious Diseases and Immunology, Department of Medicine, University of Massachusetts Medical School, Worcester, MA, USA
| | - Gregory C Gray
- College of Public Health and Health Professions and Emerging Pathogens Institute, University of Florida, Gainesville, FL, USA
| | - In-Kyu Yoon
- Department of Virology, Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand
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Sen A, Saravanan P, Balamurugan V, Bhanuprakash V, Venkatesan G, Sarkar J, Rajak KK, Ahuja A, Yadav V, Sudhakar SB, Parida S, Singh RK. Detection of subclinical peste des petits ruminants virus infection in experimental cattle. Virusdisease 2014; 25:408-11. [PMID: 25674614 DOI: 10.1007/s13337-014-0213-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2014] [Accepted: 04/05/2014] [Indexed: 11/29/2022] Open
Abstract
The present study was undertaken to investigate the possible involvement of cattle in the epidemiology of peste des petits ruminants (PPR) as subclinical carriers. Cattle were exposed experimentally to PPR virus (PPRV) infection or placed in contact with PPR infected goats. Clinical samples including heparinized/EDTA blood, plasma, peripheral blood monocyte cells (PBMCs) and clotted blood (for serum) were collected periodically from 21 days post infection (dpi) to 397 dpi (21, 45, 50, 57, 65, 95, 111, 119, 148, 190, 203 and 397 dpi) and tested for PPRV antigen, nucleic acid and antibody. Exposed cattle seroconverted and maintained PPRV specific haemagglutinin antibodies and detectable PPRV antigen/nucleic acid in blood, plasma and PBMCs from 21 to 397 dpi. PPRV was recovered from blood and PBMC collected from experimental animals at 21 dpi, initially in B95a cells and then adapted to Vero cells. The study indicated that PPRV can infect cattle subclinically and PPRV antigen/nucleic acid persist in cattle for at least 397 days.
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Affiliation(s)
- A Sen
- Division of Virology, Indian Veterinary Research Institute, Campus Mukteswar, Nainital District, 263 138 Uttarakhand India ; Animal Health Division, Indian Council of Agricultural Research-North Eastern Hill Region, Meghalaya, 793103 India
| | - P Saravanan
- Division of Virology, Indian Veterinary Research Institute, Campus Mukteswar, Nainital District, 263 138 Uttarakhand India ; Indian Veterinary Research Institute, Bangalore Campus, Bangalore, 560 024 Karnataka India
| | - V Balamurugan
- Division of Virology, Indian Veterinary Research Institute, Campus Mukteswar, Nainital District, 263 138 Uttarakhand India ; National Institute of Veterinary Epidemiology and Disease Informatics (NIVEDI), Formerly Project Directorate on Animal Disease Monitoring and Surveillance (PD_ADMAS), Hebbal, Bangalore, 560 024 Karnataka India
| | - V Bhanuprakash
- Division of Virology, Indian Veterinary Research Institute, Campus Mukteswar, Nainital District, 263 138 Uttarakhand India ; Indian Veterinary Research Institute, Bangalore Campus, Bangalore, 560 024 Karnataka India
| | - G Venkatesan
- Division of Virology, Indian Veterinary Research Institute, Campus Mukteswar, Nainital District, 263 138 Uttarakhand India
| | - J Sarkar
- Division of Virology, Indian Veterinary Research Institute, Campus Mukteswar, Nainital District, 263 138 Uttarakhand India
| | - K K Rajak
- Division of Virology, Indian Veterinary Research Institute, Campus Mukteswar, Nainital District, 263 138 Uttarakhand India
| | - A Ahuja
- Division of Virology, Indian Veterinary Research Institute, Campus Mukteswar, Nainital District, 263 138 Uttarakhand India
| | - V Yadav
- Division of Virology, Indian Veterinary Research Institute, Campus Mukteswar, Nainital District, 263 138 Uttarakhand India
| | - S B Sudhakar
- Division of Virology, Indian Veterinary Research Institute, Campus Mukteswar, Nainital District, 263 138 Uttarakhand India
| | - S Parida
- Institute for Animal Health, Pirbright Laboratory, Woking, Surrey UK
| | - R K Singh
- Division of Virology, Indian Veterinary Research Institute, Campus Mukteswar, Nainital District, 263 138 Uttarakhand India ; National Research Centre on Equines, Sirsa Road, Hisar, 125 001 Haryana India
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Zu R, Dong L, Qi X, Wang D, Zou S, Bai T, Li M, Li X, Zhao X, Xu C, Huo X, Xiang N, Yang S, Li Z, Xu Z, Wang H, Shu Y. Virological and serological study of human infection with swine influenza A H1N1 virus in China. Virology 2013; 446:49-55. [PMID: 24074566 DOI: 10.1016/j.virol.2013.07.022] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2013] [Revised: 02/06/2013] [Accepted: 07/18/2013] [Indexed: 11/16/2022]
Abstract
BACKGROUND Pigs are considered to be "mixing vessels" for the emergence of influenza viruses with pandemic potential. 2009 Pandemic Influenza H1N1 further proved this hypothesis, and raised the needs for risk assessment of human cases caused by swine influenza virus. METHODS A field investigation was conducted after a case identified with infection of European avian-like swine influenza H1N1 virus. The diagnosis was confirmed by real-time PCR, virus isolation, whole genome sequencing and serological assays. Samples from local pigs and close contacts were tested to identify the source of infection and route of transmission. RESULTS The virus from the index case was similar to viruses circulating in the local pigs. The case's grandfather was asymptomatic with sero-conversion. A total of 42.8% of swine sera were positive for European avian-like swine H1N1. CONCLUSIONS This study highlighted the importance of performing surveillance on swine influenza to monitor new virus emergence in humans.
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Affiliation(s)
- Rongqiang Zu
- Jiangsu Provincial Center for Disease Prevention and Control, Nanjing, China
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Frey CF, Gutiérrez-Expósito D, Ortega-Mora LM, Benavides J, Marcén JM, Castillo JA, Casasús I, Sanz A, García-Lunar P, Esteban-Gil A, Álvarez-García G. Chronic bovine besnoitiosis: intra-organ parasite distribution, parasite loads and parasite-associated lesions in subclinical cases. Vet Parasitol 2013; 197:95-103. [PMID: 23680543 DOI: 10.1016/j.vetpar.2013.04.023] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2013] [Revised: 04/04/2013] [Accepted: 04/14/2013] [Indexed: 11/27/2022]
Abstract
Bovine besnoitiosis caused by Besnoitia besnoiti is a chronic and debilitating disease. The most characteristic clinical signs of chronic besnoitiosis are visible tissue cysts in the scleral conjunctiva and the vagina, thickened skin and a generally poor body condition. However, many seropositive animals remain subclinically infected, and the role that these animals may play in spreading the disease is not known. The aim of the present study was to assess the intra-organ parasite distribution, the parasite load and the parasite-associated lesions in seropositive but subclinically infected animals. These animals were seropositive at the time of several consecutive samplings, had visible tissue cysts in the past and, at time of slaughter, had detectable specific anti-Besnoitia spp. antibody levels, but they did not show evident clinical signs at culling. Thus, histopathological, immunohistochemical and molecular analyses of several samples from the respiratory tract, reproductive tract, other internal organs and skin from six cows were performed. The tissue cysts were located primarily in the upper respiratory tract, i.e., in the rhinarium and larynx/pharynx (four cows), followed by the distal genital tract (vulva/vagina) and the skin of the neck (three and two cows, respectively, out of the four cows with cysts in the respiratory tract). We were unable to detect any parasites in the two remaining cows. Cysts were associated with a significant non-purulent inflammatory infiltrate consisting predominantly of T lymphocytes and activated monocytes/macrophages in two cows. The parasite burden, estimated by quantitative real-time PCR, was very low. It is noteworthy that the only animal that showed a recent increase in the antibody titre had the highest parasite burden and the most conspicuous inflammatory reaction against the cysts. In conclusion, although these cows no longer displayed any visible signs of besnoitiosis, they remained infected. Therefore, cows without visible signs of disease may still be able to transmit the parasite.
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Affiliation(s)
- C F Frey
- SALUVET, Animal Health Department, Faculty of Veterinary Sciences, Complutense University of Madrid, Ciudad Universitaria s/n, 28040 Madrid, Spain
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