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Mohamed MHA, Abdelaziz AM, Kumar S, Al-Habib MA, Megahed MM. Effect of phylogenetic diversity of velogenic Newcastle disease virus challenge on virus shedding post homologous and heterologous DNA vaccination in chickens. Avian Pathol 2017; 45:228-34. [PMID: 26813237 DOI: 10.1080/03079457.2016.1144870] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Newcastle disease (ND) is a highly devastating disease for the poultry industry as it causes high economic losses. In this present study, a DNA vaccine containing the F and HN surface antigens of a highly virulent Newcastle disease virus (NDV), NDV/1/Chicken/2005 (FJ939313), was successfully generated. Cell transfection test indicated that the vaccine expressed the F and HN genes in Hep-2 cells. The main objective of this study was to compare the extent of protection induced by DNA vaccination after homologous and heterologous NDV-challenge as determined by the amount of NDV shedding after challenge. NDV-antibody-negative chickens were vaccinated either once, twice or thrice intramuscularly at 7, 14 and 21 days old and were challenged 14 days post vaccination with either homologous virus (vaccine-matched velogenic viscerotropic Newcastle disease virus (vvNDV) strain, FJ939313), phylogenetically related to group VII, or a phylogenetically divergent heterologous virus (unmatched vvNDV strain, AY968809), which belongs to genogroup VI and shows 84.1% nucleotide similarity to the NDV-sequences of the DNA vaccine. Our data indicate that birds, which received a single dose of the DNA vaccine were poorly protected, and only 30-40% of these birds survived after challenge with high virus shedding titre. Multiple administration of the DNA vaccine induced high protection rates of 70-90% with reduced virus shedding compared to the non-vaccinated and challenged birds. Generally, homologous challenge led to reduced tracheal and cloacal shedding compared to the heterologous vvNDV strain. This study provides a promising approach for the control of ND in chickens using DNA vaccines, which are phylogenetically closely related to the circulating field strains.
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Korhonen CJ, Srinivasan S, Huang D, Ko DL, Sanders EJ, Peshu NM, Krieger JN, Muller CH, Coombs RW, Fredricks DN, Graham SM. Semen Bacterial Concentrations and HIV-1 RNA Shedding Among HIV-1-Seropositive Kenyan Men. J Acquir Immune Defic Syndr 2017; 74:250-257. [PMID: 27861240 PMCID: PMC5305287 DOI: 10.1097/qai.0000000000001244] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Accepted: 10/28/2016] [Indexed: 11/25/2022]
Abstract
INTRODUCTION HIV-1 is transmitted through semen from men to their sexual partners. Genital infections can increase HIV-1 RNA shedding in semen, but shedding also occurs in the absence of typical pathogens. We hypothesized that higher bacterial concentrations in semen would be associated with higher HIV-1 RNA levels. METHODS We analyzed semen samples from 42 HIV-1-seropositive Kenyan men using quantitative polymerase chain reaction (PCR) to assess bacterial concentrations and real-time PCR to measure HIV-1 RNA levels. Generalized estimation equations were used to evaluate associations between these 2 measures. Broad-range 16S rRNA gene PCR with pyrosequencing was performed on a subset of 13 samples to assess bacterial community composition. RESULTS Bacteria were detected in 96.6% of 88 samples by quantitative PCR. Semen bacterial concentration and HIV-1 RNA levels were correlated 0.30 (P = 0.01). The association between bacterial concentration and HIV-1 RNA detection was not significant after adjustment for antiretroviral therapy (ART) (adjusted odds ratio: 1.27, 95% CI: 0.84 to 1.91). Factors associated with semen bacterial concentration included insertive anal sex (adjusted beta 0.92, 95% CI: 0.12 to 1.73) and ART use (adjusted beta: -0.77, 95% CI: -1.50 to 0.04). Among 13 samples with pyrosequencing data, Corynebacterium spp., Staphylococcus spp., and Streptococcus spp. were most frequently detected. CONCLUSION Most of these HIV-1-infected men had bacteria in their semen. ART use was associated with undetectable semen HIV-1 RNA and lower semen bacterial concentrations, whereas insertive anal sex was associated with higher bacterial concentrations. Additional studies evaluating the relationship between semen bacteria, inflammation, mucosal immunity, and HIV-1 shedding are needed to understand implications for HIV-1 transmission.
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Murray KO, Gorchakov R, Carlson AR, Berry R, Lai L, Natrajan M, Garcia MN, Correa A, Patel SM, Aagaard K, Mulligan MJ. Prolonged Detection of Zika Virus in Vaginal Secretions and Whole Blood. Emerg Infect Dis 2017; 23:99-101. [PMID: 27748649 PMCID: PMC5176245 DOI: 10.3201/eid2301.161394] [Citation(s) in RCA: 159] [Impact Index Per Article: 22.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Infection with Zika virus is an emerging public health crisis. We observed prolonged detection of virus RNA in vaginal mucosal swab specimens and whole blood for a US traveler with acute Zika virus infection who had visited Honduras. These findings advance understanding of Zika virus infection and provide data for additional testing strategies.
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Bertasio C, Giacomini E, Lazzaro M, Perulli S, Papetti A, Lavazza A, Lelli D, Alborali G, Boniotti MB. Porcine Epidemic Diarrhea Virus Shedding and Antibody Response in Swine Farms: A Longitudinal Study. Front Microbiol 2016; 7:2009. [PMID: 28018330 PMCID: PMC5156881 DOI: 10.3389/fmicb.2016.02009] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2016] [Accepted: 11/30/2016] [Indexed: 02/03/2023] Open
Abstract
The porcine epidemic diarrhea virus (PEDV) causes an acute and highly contagious enteric disease characterized by severe enteritis, vomiting, watery diarrhea, and a high mortality rate in seronegative neonatal piglets. In the last few years, PED had a large economic impact on the swine industries in Asia and the US, and in 2014, the PEDV also re-emerged in Europe. Two main PEDV variants circulate worldwide but only the S INDEL variant, considered a mild strain, is spreading in Europe. To gain insights into the pathogenicity of this variant, its viral load and temporal shedding pattern were evaluated in piglets from infected farms. Quantitative real-time PCR (qPCR) targeting the spike gene, was validated according to the minimum information for quantitative real-time PCR experiments guidelines. The qPCR was applied to longitudinal studies conducted in four swine farms naturally infected with the PEDV S INDEL variant. Clinical data, fecal swabs, and blood samples were collected from 103 piglets at 15-30-day intervals for 2-5 months. On all four farms, diarrhea was observed in sows during gestation and in farrowing units, and the mortality rates of piglets were 18, 25, 30, and 35%. Different clinical pictures (0-50% of diarrhea positivity), viral titer levels (mean 5.3-7.2 log10 genome copies/mL), and antibody conditions (30-80% of positivity) were registered among sows on the four farms. The percentage of qPCR positive piglets varied greatly from the beginning (63-100%) to the end (0%) of the infection course. Clinical signs were present in 96% of the qPCR positive animals. Viral loads ranged from 8.5 log10 to 4 log10 genome copies/mL in suckling pigs at 3-6 days of age and were not statistically different among farms, despite the different patterns observed in sows. After 2-3 weeks, only a few piglets still showed detectable viral levels and clinical signs, and they developed antibody responses. Moreover, co-infections with other pathogens and biosecurity procedures limiting the circulation of the virus could have influenced the severity of PED infection. QPCR and clinical data were useful in understanding the dynamics of PEDV infections and, therefore, in implementing appropriate control measures.
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Miyazaki Y, Namba H, Torigoe S, Watanabe M, Yamashita N, Ogawa H, Morishima T, Yamada M. Monitoring of human herpesviruses-6 and -7 DNA in saliva samples during the acute and convalescent phases of exanthem subitum. J Med Virol 2016; 89:696-702. [PMID: 27648817 DOI: 10.1002/jmv.24690] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/17/2016] [Indexed: 02/06/2023]
Abstract
The amounts of the DNAs of human herpesviruses-6 (HHV-6) and -7 (HHV-7) in saliva samples were monitored during the acute and convalescent phases of exanthem subitum (ES) to elucidate the kinetics of virus shedding after ES. A total of 247 saliva samples were collected from 17 children (5 males and 12 females: 8-31 months old at onset). The monitoring period ranged from 152 to 721 days after onset, and in 15 children it was longer than 1 year. Among the 17 cases, 16 were attributed to HHV-6B, while a single case was attributed to HHV-7. Detection rates and average amounts of HHV-6 DNA in saliva samples after ES attributed to HHV-6B were low in the acute phase, increased to the maximum in the convalescent phase at 3-7 months, and then decreased. In addition, to investigate the source of infection, saliva samples from the older siblings (age 3-9 years) and parents of ES patients and children with a history of ES were also examined. The detection rate of HHV-6 DNA in saliva samples from 3- to 9-year-old children was significantly higher than the rate in adult saliva samples. Taken together, these findings suggest that the saliva of children in the convalescent phase of ES might be a more likely source of HHV-6 infection than that of adults. J. Med. Virol. 89:696-702, 2017. © 2016 Wiley Periodicals, Inc.
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Gharaibeh S, Amareen S. Vaccine Efficacy Against a New Avian Influenza (H9N2) Field Isolate from the Middle East (Serology and Challenge Studies). Avian Dis 2016; 59:508-11. [PMID: 26629624 DOI: 10.1637/11123-050615-reg] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Avian influenza subtype H9N2 is endemic in many countries in the Middle East. The reported prevalence of infection was variable between countries and ranged from 28.7% in Tunisia to 71% in Jordan. Several commercial killed whole-virus vaccine products are used as monovalent or bivalent mixed with Newcastle disease virus. Recently, we have noticed that many of the vaccinated broiler flocks did not show a production advantage over nonvaccinated flocks in the field. A new avian influenza field virus (H9N2) was isolated from these vaccinated and infected broiler flocks in 2013. This virus had 89.1% similarity of its hemagglutinin (HA) gene to the classical virus used for manufacturing the classical vaccine. Inactivated autogenous vaccine was manufactured from this new field isolate to investigate its serological response and protection in specific-pathogen-free (SPF) and breeder-male chickens compared to the classical vaccine. Oropharyngeal virus shedding of vaccinated breeder-male chickens was evaluated at 3, 9, 10, and 14 days postchallenge (DPC). Percentage of chickens shedding the virus at 3 DPC was 64%, 50%, and 64% in the classical vaccine group, autogenous vaccine group, and the control challenged group, respectively. At 7 DPC percentage of virus shedding was 42%, 7%, and 64% in the classical vaccine group, autogenous vaccine group, and the control challenged group, respectively. At 10 DPC only 9% of classical vaccine group was shedding the virus and there was no virus shedding in any of the groups at 14 DPC. There was statistical significance difference (P < 0.05) in shedding only at 7 DPC between the autogenous vaccine group and the other two groups. At 42 days of age (14 DPC), average body weight was 2.720, 2.745, 2.290, and 2.760 kg for the classical vaccine group, autogenous vaccine group, control challenged group, and control unchallenged group, respectively. Only the control challenged group had significantly (P < 0.05) lower average body weight. In another experiment, vaccinated SPF chicks had hemagglutination inhibition (HI) geometric mean titers (GMTs), with classical antigen, of 8.7 and 3.1 log 2 for classical and autogenous vaccine groups, respectively. When the autogenous antigen was used for HI, GMTs were 6.0 and 8.1 log 2, respectively. Both vaccines protected against body weight suppression after challenge. However, autogenous vaccine elicited significantly higher HI titer and reduced viral shedding at 7 DPC. In conclusion, it is important to revise the vaccine virus strains used in each region to protect against and control infection from new field strains. Further field experiments are needed to demonstrate the efficacy of new vaccines under field conditions.
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Graham SM, Chohan V, Ronen K, Deya RW, Masese LN, Mandaliya KN, Peshu NM, Lehman DA, McClelland RS, Overbaugh J. Genital Shedding of Resistant Human Immunodeficiency Virus-1 Among Women Diagnosed With Treatment Failure by Clinical and Immunologic Monitoring. Open Forum Infect Dis 2016; 3:ofw019. [PMID: 26966695 PMCID: PMC4784013 DOI: 10.1093/ofid/ofw019] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2015] [Accepted: 01/25/2016] [Indexed: 11/22/2022] Open
Abstract
Detection of resistant HIV-1 in genital secretions of women failing first-line therapy was associated with a greater number of resistance mutations in plasma. While genital resistance emerged later than plasma resistance, genital shedding could increase risk for transmitted drug resistance. Background. The accumulation of human immunodeficiency virus (HIV) resistance mutations can compromise treatment outcomes and promote transmission of drug-resistant virus. We conducted a study to determine the duration and evolution of genotypic drug resistance in the female genital tract among HIV-1-infected women failing first-line therapy. Methods. Treatment failure was diagnosed based on World Health Organization (WHO) clinical or immunologic criteria, and second-line therapy was initiated. Stored plasma and genital samples were tested to determine the presence and timing of virologic failure and emergence of drug resistance. The median duration of genital shedding of genotypically resistant virus prior to regimen switch was estimated. Results. Nineteen of 184 women were diagnosed with treatment failure, of whom 12 (63.2%) had confirmed virologic failure at the switch date. All 12 women with virologic failure (viral load, 5855–1 086 500 copies/mL) had dual-class resistance in plasma. Seven of the 12 (58.3%) had genital HIV-1 RNA levels high enough to amplify (673–116 494 copies/swab), all with dual-class resistance. The median time from detection of resistance in stored samples to regimen switch was 895 days (95% confidence interval [CI], 130–1414 days) for plasma and 629 days (95% CI, 341–984 days) for genital tract secretions. Conclusions. Among women diagnosed with treatment failure using WHO clinical or immunologic criteria, over half had virologic failure confirmed in stored samples. Resistant HIV-1 RNA was shed in the genital tract at detectable levels for ≈1.7 years before failure diagnosis, with steady accumulation of mutations. These findings add urgency to the ongoing scale-up of viral load testing in resource-limited settings.
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Bliss N, Nelson SW, Nolting JM, Bowman AS. Prevalence of Influenza A Virus in Exhibition Swine during Arrival at Agricultural Fairs. Zoonoses Public Health 2016; 63:477-85. [PMID: 26750204 DOI: 10.1111/zph.12252] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2015] [Indexed: 11/28/2022]
Abstract
The exhibition swine at agricultural fairs provides a critical human-swine interface that allows for the bidirectional transmission of influenza A virus (IAV). Previous IAV surveillance at the end of fairs has resulted in frequent detection of IAV-infected swine; little is known, however, about the frequency with which swine arrive at fairs already infected with IAV. We investigated the IAV prevalence among exhibition swine entering fairs to better understand the epidemiology of IAV in this unique human-swine interface. In 2014, snout wipes were collected from 3547 swine during the first day of nine agricultural exhibitions in Indiana and Ohio. Samples were screened for IAV using rRT-PCR and positive samples were inoculated into cultured cells for virus isolation. The overall IAV prevalence detected among swine arriving at exhibitions was 5.3% (188/3547) via rRT-PCR and 1.5% (53/3547) via virus isolation, with IAV being detected and recovered from swine at 5 of the 9 exhibitions. Within the fairs with IAV-positive swine, the individual exhibition IAV prevalence ranged from 0.2% (1/523) to 34.4% (144/419) using rRT-PCR and 0.2% (1/523) to 10.3% (43/419) with virus isolation. Single IAV subtypes were detected at three of the fairs but subtype diversity was detected among the pigs at two fairs as both H1N1 and H3N2 were recovered from incoming swine. At two of the exhibitions, a temporal relationship was observed between the order of the individual swine in sampling and the associated IAV rRT-PCR results, indicating the fomite transmission of IAV through common contact surfaces may occur. With the knowledge that a small proportion of swine arrive at fairs shedding IAV, resources should be directed towards preventive strategies focused on limiting transmission during fairs to protect swine and humans during exhibitions.
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Kwong JC. Editorial Commentary: Symptoms and Viral Shedding in Naturally Acquired Influenza Infections. Clin Infect Dis 2015; 62:438-9. [PMID: 26518470 PMCID: PMC4725383 DOI: 10.1093/cid/civ914] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2015] [Accepted: 10/16/2015] [Indexed: 11/14/2022] Open
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Yan XC, Wang JH, Wang B, Huang LL, Zhou LQ, Zhu B, Liang Y. Study of human cytomegalovirus replication in body fluids, placental infection, and miscarriage during the first trimester of pregnancy. J Med Virol 2015; 87:1046-53. [PMID: 25732959 DOI: 10.1002/jmv.24158] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/07/2015] [Indexed: 11/08/2022]
Abstract
Intrauterine infection caused by human cytomegalovirus (HCMV) can lead to embryo, fetal, and neonatal damage. The prevalence of HCMV replication in body fluids (blood, urine, and cervicovaginal secretion) was investigated, and its effects on HCMV vertical transmission and miscarriages in early pregnant women were evaluated. HCMV DNA in body fluids was detected in 1,064 early pregnant women (624 normal pregnancies and 440 miscarriages). There were 101 cases who were HCMV DNA positive in cervicovaginal secretion and the rates were 10.9% (48/440 cases) and 8.5% (53/624 cases) in miscarriages and normal pregnancies, respectively (P > 0.05). A total of 101 cases (63 and 38 cases with and without HCMV DNA in cervicovaginal secretion, respectively) were given HCMV DNA detection in placental villi/deciduas. There were five cases (7.9%; two normal pregnancies and three miscarriages) with HCMV DNA in placental villi/deciduas among the 63 cases with HCMV DNA in cervicovaginal secretion, whereas none of the other 38 cases were detected HCMV DNA positive in their placental villi/deciduas. The percentage of HCMV DNA in placental villi/deciduas was higher in miscarriage group (9.1% [3/33]) than that in the normal pregnancy group (6.7% [2/30]), but there was no statistical significance (P > 0.05). Two cases with a higher HCMV loads in cervicovaginal secretion and placental villi/deciduas had miscarriages. These findings suggest that HCMV replication in cervicovaginal secretion can involve in placental HCMV infection, and high HCMV DNA loads in cervicovaginal secretion and placental villi/deciduas are associated with miscarriage.
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Fielding JE, Kelly HA, Mercer GN, Glass K. Systematic review of influenza A(H1N1)pdm09 virus shedding: duration is affected by severity, but not age. Influenza Other Respir Viruses 2013; 8:142-50. [PMID: 24299099 PMCID: PMC4186461 DOI: 10.1111/irv.12216] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/26/2013] [Indexed: 01/02/2023] Open
Abstract
Duration of viral shedding following infection is an important determinant of disease transmission, informing both control policies and disease modelling. We undertook a systematic literature review of the duration of influenza A(H1N1)pdm09 virus shedding to examine the effects of age, severity of illness and receipt of antiviral treatment. Studies were identified by searching the PubMed database using the keywords ‘H1N1’, ‘pandemic’, ‘pandemics’, ‘shed’ and ‘shedding’. Any study of humans with an outcome measure of viral shedding was eligible for inclusion in the review. Comparisons by age, degree of severity and antiviral treatment were made with forest plots. The search returned 214 articles of which 22 were eligible for the review. Significant statistical heterogeneity between studies precluded meta-analysis. The mean duration of viral shedding generally increased with severity of clinical presentation, but we found no evidence of longer shedding duration of influenza A(H1N1)pdm09 among children compared with adults. Shorter viral shedding duration was observed when oseltamivir treatment was administered within 48 hours of illness onset. Considerable differences in the design and analysis of viral shedding studies limit their comparison and highlight the need for a standardised approach. These insights have implications not only for pandemic planning, but also for informing responses and study of seasonal influenza now that the A(H1N1)pdm09 virus has become established as the seasonal H1N1 influenza virus.
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Atmar RL, Opekun AR, Gilger MA, Estes MK, Crawford SE, Neill FH, Ramani S, Hill H, Ferreira J, Graham DY. Determination of the 50% human infectious dose for Norwalk virus. J Infect Dis 2013; 209:1016-22. [PMID: 24253285 DOI: 10.1093/infdis/jit620] [Citation(s) in RCA: 214] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
BACKGROUND Noroviruses are the most common cause of gastroenteritis in the United States. An understanding of the infectious dose of these viruses is important for risk assessment studies. METHODS Healthy adults were enrolled in a randomized, double-blind, placebo-controlled evaluation of different dosages of Norwalk virus. Eligible subjects were monitored for clinical gastroenteritis, and infection status was determined. The presence of virus in vomitus was also assessed. RESULTS Fifty-seven persons were enrolled; 8 received placebo and an additional 8 persons were considered to be nonsusceptible on the basis of being secretor negative. Twenty-one persons were infected (all blood group O or A), and 67% of those infected developed viral gastroenteritis. The 50% human infectious dose was calculated to be 3.3 reverse transcription polymerase chain reaction units (approximately 1320 genomic equivalents [gEq]) for secretor-positive blood group O or A persons and 7.0 (approximately 2800 gEq) for all secretor-positive persons. The time of illness onset was inversely correlated with inoculum dose. The maximal concentration of virus shedding was higher for persons with gastroenteritis. Norwalk virus was identified in 15 of 27 (56%) vomitus samples at a median concentration of 41 000 gEq/mL. CONCLUSIONS The 50% human infectious dose measured is higher than previous estimates and similar to that of other RNA viruses. Clinical Trials Registration NCT00138476.
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Mukhopadhya I, Sarkar R, Menon VK, Babji S, Paul A, Rajendran P, Sowmyanarayanan TV, Moses PD, Iturriza-Gomara M, Gray JJ, Kang G. Rota virus shedding in symptomatic and asymptomatic children using reverse transcription-quantitative PCR. J Med Virol 2013; 85:1661-8. [PMID: 23775335 DOI: 10.1002/jmv.23641] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/04/2013] [Indexed: 11/09/2022]
Abstract
Reverse transcription-real-time polymerase chain reaction (RT-qPCR) for the VP6 gene was used to study group A rotavirus shedding in children with symptomatic and asymptomatic rotavirus infection. Sequential stool samples (n = 345) from 10 children with rotavirus associated diarrhea and from five children (n = 161) with asymptomatic rotavirus infection were collected over a period of 2 months. A RT-qPCR assay on the samples using a rotavirus VP6 plasmid standard demonstrated high reproducibility, with an inter-assay coefficient of variation (CV) of 1.40-2.97% and an intra-assay CV of 0.03-3.03%. The median duration of shedding was longer in children with diarrhea compared to asymptomatic children (24 days vs. 18 days; P = 0.066). The median quantitation cycle (C(q)) at presentation in symptomatic children was 17.21 compared to 30.98 in asymptomatic children (P = 0.086). The temporal pattern in symptomatic children consisted of a high initial viral shedding coinciding with the duration of diarrhea, followed by a rapid fall, and then a small increase in secondary shedding 21 days later. Compared to children with rotavirus diarrhea, those with asymptomatic infection shed lower quantities of virus throughout the observation period. No difference was noted between the G and P genotypes of samples collected at onset of infection and during the shedding period. Shedding was intermittent in a subset of children in both groups. RT-qPCR is a useful method to characterize shedding patterns.
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Kay M, Zerr DM, Englund JA, Cadwell BL, Kuypers J, Swenson P, Kwan-Gett TS, Bell SL, Duchin JS. Shedding of pandemic (H1N1) 2009 virus among health care personnel, Seattle, Washington, USA. Emerg Infect Dis 2011; 17:639-44. [PMID: 21470453 PMCID: PMC3377395 DOI: 10.3201/eid1704.100866] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
The Centers for Disease Control and Prevention (CDC) recommends that health care personnel (HCP) infected with pandemic influenza (H1N1) 2009 virus not work until 24 hours after fever subsides without the use of antipyretics. During an influenza outbreak, we examined the association between viral shedding and fever among infected HCP. Participants recorded temperatures daily and provided nasal wash specimens for 2 weeks after symptom onset. Specimens were tested by using PCR and culture. When they met CDC criteria for returning to work, 12 of 16 HCP (75%) (95% confidence interval 48%-93%) had virus detected by PCR, and 9 (56%) (95% confidence interval 30%-80%) had virus detected by culture. Fever was not associated with shedding duration (p = 0.65). HCP might shed virus even when meeting CDC exclusion guidelines. Further research is needed to clarify the association between viral shedding, symptoms, and infectiousness.
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Tan KE, Anderson M, Krajden M, Petric M, Mak A, Naus M. Mumps virus detection during an outbreak in a highly unvaccinated population in British Columbia. CANADIAN JOURNAL OF PUBLIC HEALTH = REVUE CANADIENNE DE SANTE PUBLIQUE 2011; 102:47-50. [PMID: 21485966 PMCID: PMC6974105] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 07/05/2010] [Accepted: 09/13/2010] [Indexed: 11/14/2023]
Abstract
OBJECTIVES Control measures of mumps involve isolation of those symptomatic or potentially exposed. Recent guidelines have recommended shortening the isolation period from 9 days to 5 days after the onset of parotitis, despite using mainly historical evidence. In British Columbia, mumps circulated in a predominantly unvaccinated population in 2008. We compared laboratory findings between the different vaccination groups and assessed the period of mumps viral detection after onset of parotitis. METHODS Demographic and clinical data were collected according to guidelines during the course of the outbreak. Clinical specimens, including buccal swabs, urine, CSF and sera, were collected on a single visit upon presentation for diagnosis. Laboratory diagnosis of mumps was confirmed by either virus detection by PCR and/or isolation in cell culture from clinical specimens, or by serology. RESULTS Laboratory testing confirmed mumps on 85 (74%) of 115 cases by virus detection and/or serology. Thirty-nine (78%) of 50 cases had virus detected within the first 5 days after onset of parotitis, with the rate highest in specimens collected early. However, virus could be detected in 5 (56%) of 9 cases after day 5 and up to day 9. CONCLUSION Our study questions whether a 5-day isolation period is sufficient to prevent mumps transmission in a susceptible population. Our observations are based on single specimen submission, whereas an optimal study design would entail serial collection after presentation of parotitis, as this reflects true viral shedding. Further investigations are warranted to validate patient isolation guidelines.
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Tan KE, Anderson M, Krajden M, Petric M, Mak A, Naus M. Mumps virus detection during an outbreak in a highly unvaccinated population in British Columbia. CANADIAN JOURNAL OF PUBLIC HEALTH = REVUE CANADIENNE DE SANTE PUBLIQUE 2011; 102:47-50. [PMID: 21485966 PMCID: PMC6974105 DOI: 10.1007/bf03404876] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2010] [Accepted: 09/13/2010] [Indexed: 05/30/2023]
Abstract
OBJECTIVES Control measures of mumps involve isolation of those symptomatic or potentially exposed. Recent guidelines have recommended shortening the isolation period from 9 days to 5 days after the onset of parotitis, despite using mainly historical evidence. In British Columbia, mumps circulated in a predominantly unvaccinated population in 2008. We compared laboratory findings between the different vaccination groups and assessed the period of mumps viral detection after onset of parotitis. METHODS Demographic and clinical data were collected according to guidelines during the course of the outbreak. Clinical specimens, including buccal swabs, urine, CSF and sera, were collected on a single visit upon presentation for diagnosis. Laboratory diagnosis of mumps was confirmed by either virus detection by PCR and/or isolation in cell culture from clinical specimens, or by serology. RESULTS Laboratory testing confirmed mumps on 85 (74%) of 115 cases by virus detection and/or serology. Thirty-nine (78%) of 50 cases had virus detected within the first 5 days after onset of parotitis, with the rate highest in specimens collected early. However, virus could be detected in 5 (56%) of 9 cases after day 5 and up to day 9. CONCLUSION Our study questions whether a 5-day isolation period is sufficient to prevent mumps transmission in a susceptible population. Our observations are based on single specimen submission, whereas an optimal study design would entail serial collection after presentation of parotitis, as this reflects true viral shedding. Further investigations are warranted to validate patient isolation guidelines.
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Chang JT, Li X, Liu HJ, Yu L. Ovine rotavirus strain LLR-85-based bovine rotavirus candidate vaccines: construction, characterization and immunogenicity evaluation. Vet Microbiol 2010; 146:35-43. [PMID: 20488633 PMCID: PMC7117303 DOI: 10.1016/j.vetmic.2010.04.016] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2009] [Revised: 04/16/2010] [Accepted: 04/19/2010] [Indexed: 02/02/2023]
Abstract
Group A bovine rotaviruses (BRVs) are the most important cause of diarrheal diseases in neonatal calves and cause significant morbidity and mortality in the young animals, and epidemiologic surveillance of bovine rotavirus G genotypes conducted in various cattle populations throughout the world has shown that approximately 90% of the bovine rotavirus isolates belong to G6 and G10. Based on the modified Jennerian approach to immunization, we constructed and characterized a reassortant rotavirus stain, which bears a single bovine rotavirus VP7 gene encoding G genotype 6 specificity while the remaining 10 genes are derived from the ovine attenuated rotavirus LLR-85. The reassortant rotavirus strain, named as R191, and its parental virus strain LLR-85 were combined as bivalent vaccine candidates to inoculate the colostrums-deprived neonatal calves for evaluation of the immunogenicity. The calves were orally inoculated with the reassortant R191 (group 1), the parental rotavirus LLR-85 (group 2), or combined the R191 and LLR-85 (group 3), and serum specimens were detected to determine the immune response of IgG and IgA antibodies. Results showed that seroconversion to positivity for IgG and IgA antibodies occurred at postinoculation day (PID) 10 in all of the inoculated calves, and the highest titers of the serum IgG (range 1:800 to 1:6400) and IgA (range 1:800 to 1:3200) antibodies were obtained at PID 21 for all calves. Meanwhile, virus shedding was detected after inoculation, showing that the inoculated virus was positive in 2 of 77 fecal specimens (2.6%) collected from the inoculated calves during the first 7 days of oral inoculation with the rotavirus vaccine candidates. The results suggested that the rotavirus strains R191 and LLR-85 are promising bivalent vaccine candidates for the prevention of bovine G6 and G10 rotavirus infection.
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Hawes SE, Sow PS, Stern JE, Critchlow CW, Gottlieb GS, Kiviat NB. Lower levels of HIV-2 than HIV-1 in the female genital tract: correlates and longitudinal assessment of viral shedding. AIDS 2008; 22:2517-25. [PMID: 19005275 PMCID: PMC3726195 DOI: 10.1097/qad.0b013e328315cdbc] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND The differing magnitude of the HIV-1 and HIV-2 epidemics is likely a consequence of differing transmission rates between the two viruses. Similar to other sexually transmitted pathogens, risk of HIV-1 and HIV-2 transmission is likely associated with the presence and amount of HIV in the genital tract. Thus, understanding patterns of, and risk factors for HIV genital tract shedding is critical to effective control of HIV transmission. METHODS We evaluated HIV DNA and RNA detection in cervicovaginal specimens among 168 HIV-1 and 50 HIV-2-infected women in Senegal, West Africa. In a subset of 31 women (20 with HIV-1, 11 with HIV-2), we conducted a prospective study in which cervicovaginal specimens were taken at 3-day intervals over a 6-week period. RESULTS We found significantly lower rates and levels of HIV-2 RNA (58% shedding; 13% with >1000 copies/ml) in the female genital tract than HIV-1 RNA (78% shedding; 40% with >1000 copies/ml) (P = 0.005 and 0.005, respectively), and shedding correlated with plasma viral load irrespective of virus type (odds ratio = 1.9, 95% confidence interval = 1.3-2.8 for each log10 increase in HIV viral RNA). Plasma viral load, not HIV type, was the strongest predictor of genital viral load. Over 80% of closely monitored women, regardless of HIV type, had at least intermittent HIV RNA detection during every 3-day sampling over a 6-week time period. CONCLUSION These data help in explaining the different transmission rates between HIV-1 and HIV-2 and may provide new insights regarding prevention.
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Abstract
BACKGROUND Amantadine hydrochloride and rimantadine hydrochloride have antiviral properties, but they are not widely used due to a lack of knowledge of their potential value and concerns about possible adverse effects. OBJECTIVES The objective of this review was to assess the efficacy, effectiveness and safety ("effects") of amantadine and rimantadine in healthy adults. SEARCH STRATEGY We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library Issue 3, 2005), MEDLINE (2003 to August Week 4, 2005), EMBASE (October 2003 to July 2005) and reference lists of articles. SELECTION CRITERIA Randomised and quasi-randomised studies comparing amantadine and/or rimantadine with placebo, control medication or no intervention, or comparing doses or schedules of amantadine and/or rimantadine in healthy adults. DATA COLLECTION AND ANALYSIS For prophylaxis (prevention) trials the numbers of participants with clinical influenza (influenza-like-illness or ILI) or with confirmed influenza A and adverse effects were analysed. Analysis for treatment trials was of the mean duration of fever, length of hospital stay and adverse effects. MAIN RESULTS Amantadine prevented 25% of ILI cases (95% confidence interval (CI) 13% to 36%), and 61% of influenza A cases (95% CI 35% to 76%). Amantadine reduced duration of fever by one day (95% CI 0.7 to 1.2). Rimantadine demonstrated comparable effectiveness, but there were fewer trials and the results for prophylaxis were not statistically significant. Both amantadine and rimantadine induced significant gastrointestinal adverse effects. Adverse effects of the central nervous system and study withdrawals were significantly more common with amantadine than rimantadine. Neither drug affected the rate of viral shedding from the nose and the course of asymptomatic influenza. AUTHORS' CONCLUSIONS Amantadine and rimantadine have comparable efficacy and effectiveness in relieving or treating symptoms of influenza A in healthy adults, although rimantadine induces fewer adverse effects than amantadine. The effectiveness of both drugs in interrupting transmission is probably low. Routine use of both drugs should be discouraged and both drugs should only be used when all other measures fail.
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Robertson CA, Lowther SA, Birch T, Tan C, Sorhage F, Stockman L, McDonald C, Lingappa JR, Bresnitz E. SARS and pregnancy: a case report. Emerg Infect Dis 2004; 10:345-8. [PMID: 15030710 PMCID: PMC3322896 DOI: 10.3201/eid1002.030736] [Citation(s) in RCA: 114] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
We report a laboratory-confirmed case of severe acute respiratory syndrome (SARS) in a pregnant woman. Although the patient had respiratory failure, a healthy infant was subsequently delivered, and the mother is now well. There was no evidence of viral shedding at delivery. Antibodies to SARS virus were detected in cord blood and breast milk.
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