Frequency Of Viral Shedding Research Articles

Clinical symptoms and faecal shedding of SARS-CoV-2 RNA among hospitalized COVID-19 patients: Implication for transmission.

SARS-CoV-2 shedding in human stool has been suggested as a probable route for faeco-oral transmission of the virus due to the availing evidence on the infectivity and pathogenicity of similar highly infectious respiratory viruses. Determining association of SARS-CoV-2 shedding in stools and presenting clinical status might be useful for prediction of the viral transmission spectrum and disease outcome. This study involved a descriptive cross-sectional survey of 91 consenting hospitalized, confirmed COVID-19 patients in Infectious Disease Isolation Centre, Oyo State, Nigeria. Socio-demographic characteristics and other ancillary data were collected from patient's hospital records with the aid of a structured investigator administered questionnaire. The laboratory detection of SARS-CoV-2 RNA in the stool of patients was performed using RT-PCR method. 27 (29.7%) of the 91 COVID-19 patients shed SARS-CoV-2 in their stools. The frequency of male (38.3%) patients shedding the virus in stools was higher than female (12.9%) patients (P = 0.012). Higher proportion of patients who had symptoms (41.2%) at admission shed the virus in their stool (P <0.007); particularly, fever (0.001), fatigue (0.003), headache (0.003), catarrh (0.001), and loss of smell (0.009). The frequency of viral shedding in stool was higher among patients with loss of taste (p = 0.028). Viral shedding in stool was significantly associated with low CT values (47.2%) and moderate CT value (21.4%) (P<0.05). Multivariate analysis showed that patients with moderate CT-value (OR = 0.28, 95% CI: 0.08-0.94, P = 0.039) and high CT-value (OR = 0.08, 95% CI: 0.01-0.80, P = 0.033) were less likely to shed the virus in stool. The gastrointestinal tract could be a route of SARS-CoV-2 transmission irrespective of the patients' clinical status. The low and moderate CT values of the nasopharyngeal swab is associated with shedding of the virus in patients' stools, although infectivity will depend on viral activity obtainable from further laboratory test analyses, such as viral culture.

Shedding of bovine alphaherpesvirus-1 in bovine extended frozen semen in Indian semen stations: A longitudinal analysis

Infectious bovine rhinotracheitis (IBR) caused by bovine alphaherpesvirus 1 (BoHV-1) is an economically important disease of cattle and buffaloes. Following acute infection, the virus usually attains latency in the sensory neurons. Stress-induced reactivation of latency can cause the infected animals to intermittently shed the virus in body secretions including semen. A longitudinal analysis was carried out to study BoHV-1 shedding in the semen of IBR seropositive cattle and buffaloes. The study involved data generated from the screening of 119,850 extended frozen semen (EFS) batches, collected from 1,229 IBR seropositive bulls, over a period of four years (April 2015 to March 2019). A TaqMan based real-time PCR assay was employed to detect the gB gene BoHV-1 DNA in the EFS batch samples. Each sample was tested in duplicate and amplification in any of the replicates at or below the threshold cycle (Ct ≤ 40) was considered positive. The overall positivity of BoHV-1 in EFS batches was 1.18%. About 41% of the bulls (509 of 1,229) were found to have excreted the virus in semen at least once during the study period. The frequency of viral shedding in buffaloes (0.96%) was significantly lower than that of cattle (1.3%) (p < 0.001). No significant difference was noted in the rate of shedding between the first and the second ejaculates collected on the same day (p = 0.607). The rate of shedding also did not vary among various breeds of cattle (p = 0.454) or with the age of the bulls (p = 0.054). No significant variation in the shedding rate was observed in cattle across different seasons (p = 0.101); while in buffaloes, the rate was higher in autumn (1.2%) than in winter (0.7%) (p = 0.037). The difference in positivity among semen stations was statistically significant (p < 0.001). Analysis of data revealed that ≥100 EFS batch samples/bull were screened from 361 of the 1,229 bulls included in the study. None of the EFS batches screened from 39 of these 361 bulls were found positive during the four years, suggesting they were non-shedders. Further research is warranted to delineate the underlying features of the seropositive non-shedders; following which an adequate risk assessment may be made for the maintenance of infected but non-shedding bulls in semen production.

Frequent Detection of Pandemic (H1N1) 2009 Virus in Stools of Hospitalized Patients

A novel subtype of influenza A virus called pandemic (H1N1) 2009 virus showed global outbreaks in 2009. Previous studies reported that gastrointestinal symptoms such as diarrhea, vomiting, and abdominal pain were frequent in patients with pandemic (H1N1) 2009 virus infection (3, 4, 5). However, the frequency of viral shedding in this pandemic (H1N1) 2009 virus infection was not well known. We recovered pandemic (H1N1) 2009 virus from stools of hospitalized H1N1-positive patients. From 10 November to 31 December 2009, 1,774 patients were diagnosed as having pandemic (H1N1) 2009 virus infections by real-time reverse transcription-PCR (RT-PCR) from nasopharyngeal swab samples in a tertiary-care hospital located in Seoul, South Korea. Among them, 96 patients required hospitalization due to progression to pneumonia or febrile convulsion, acute gastroenteritis, or underlying illnesses. Their stool samples were requested to be collected at admission, irrespective of gastrointestinal symptoms. A total of 65 patients submitted their stool samples at 0 to 8 days after the onset of flu symptoms and were included in this study (Table ​(Table1).1). Twelve patients (18.5%) complained of diarrhea during the hospitalization period. All of them were self-limited, and only one patient showed a pathogen, Salmonella group B, in routine stool cultures. This study was approved by the Sanggye Paik Hospital institutional review board. TABLE 1. Demographic characteristics categorized by the presence of viral RNA in stools among the study population hospitalized with pandemic (H1N1) 2009 virus Viral RNA in stool was isolated using the QIAamp virus RNA minikit (Qiagen, Crawley, United Kingdom). Pandemic (H1N1) 2009 virus was detected by two kinds of RT-PCR kits, the Anyplex FluA new H1N1 kit (SeeGene, Seoul, South Korea) and TaqMan Influenza A MGB assays (Applied Biosystems). Pandemic (H1N1) 2009 virus was recovered from stools of 16 patients (24.6%). Nine of them (56.3%) did not complain of any gastrointestinal symptoms during hospitalization. Only 4 patients simultaneously presented diarrhea and fecal excretion of pandemic (H1N1) 2009 virus. Comparing stool pandemic (H1N1) 2009-positive and -negative groups, no difference of frequency was noticed for diarrhea (P = 0.683), nausea (P = 0.746), vomiting (P = 0.898), and abdominal pain (P = 0.977) (Table ​(Table11). The clinical significance and pathophysiology of fecal influenza A virus excretion are not yet clear (1, 9). However, avian influenza A (H5N1) virus has been known to cause severe gastrointestinal manifestations and to replicate in human intestinal tissues (2, 7, 8). To et al. detected pandemic (H1N1) 2009 virus in stool from 4 of 9 patients with positive viral culture from the specimen with the highest viral load (6). This finding suggested the fecal shedding of viable pandemic (H1N1) 2009 virions. In this study, fecal excretion of pandemic (H1N1) 2009 virus was not correlated with the presence of gastrointestinal symptoms as described for avian influenza A (H5N1) virus (7). This study has some limitations: outpatients were not included and virus cultures and quantifications were not performed. However, our data show that considerable numbers of patients shed pandemic (H1N1) 2009 virus in their stool, even in the absence of diarrhea. The frequent detection of fecal pandemic (H1N1) 2009 virus excretion deserves attention in the study of infection control to prevent viral dissemination.

Herpes Simplex Virus Type 2 Infection in Young Adult Women: Risk Factors for Infection and Frequency of Viral Shedding

Population-based studies suggest that acquisition of herpes simplex virus 2 (HSV 2) is most common between ages 20 and 29, especially in minority women. We examined HSV 2 infection and viral shedding in a cohort of young women. Women, age 18 to 24 (median 21), who were part of an observational cohort enrolled between ages 14 to 17, had blood obtained for HSV 2 antibody. Intensive diary collections on sexual behavior and genital symptoms and weekly vaginal swabs were obtained at regular intervals. HSV 2 antibodies were detected in 43 of 127 participants (33.9%), only 4 of whom were previously known to be positive. Factors associated with a positive test included older age, years of sexual activity, and number of lifetime partners. Testing for HSV 2 DNA by polymerase chain reaction on weekly vaginal swabs from a 13-week sampling period for each HSV 2 antibody positive participant showed 32 of 43 (74.4%) were positive at least once. The positive predictive value of pain for viral shedding was poor. HSV 2 infection is very common among young adult women, but symptomatic genital herpes is not. Shedding of HSV 2 DNA can be detected in most antibody positive persons. Early intervention strategies will be needed to control HSV 2 infection.

Effect of a beta-adrenergic antagonist, propranolol, on induced HSV-1 ocular recurrence in latently infected rabbits

PURPOSE. Propranolol, a beta-adrenergic antagonist, has been shown to block hyperthermically-induced ocular recurrence of HSV-1 in mice and reduce spontaneous ocular viral shedding and herpetic corneal lesions in latently infected rabbits. The present study was performed to determine the effect of propranolol on epinephrine iontophoresis-induced ocular recurrence and immunosuppression-induced ocular recurrence in the rabbit eye model. METHODS. New Zealand white rabbits were infected with HSV-1 strain 17Syn + or McKrae. After latency was established, the animals were injected intramuscularly with saline (placebo), or propranolol (5–200 mg/kg) twice daily, and then induced with epinephrine iontophoresis or cyclophosphamide and dexamethasone administration. Tear film swabs were cultured to determine the frequency of viral shedding. RESULTS. Propranolol administered at a range of doses did not affect the frequency or duration of viral shedding following epinephrine or cyclophosphamide/dexamethasone induction as compared to saline treatment. CONCLUSION. These results demonstrate that propranolol does not significantly reduce ocular HSV-1 shedding following induction by epinephrine iontophoresis or immunosuppression. By inference, these results suggest two possibilities: (1) that viral pathways leading to spontaneous and induced shedding of virus are under separate control mechanisms or (2) in rabbits, these inducers are of such potency that propranolol is ineffectual.

A Double-Blind Study of Oral Acyclovir for Suppression of Recurrences of Genital Herpes Simplex Virus Infection

Patients with frequently recurring genital herpes were enrolled in a double-blind placebo-controlled trial comparing 200-mg acyclovir capsules, given five or two times daily, with placebo. Of 47 placebo recipients, 44 (94 per cent) had recurrences during the 120-day treatment period, compared with 13 (29 per cent) of 45 patients treated with acyclovir five times daily and 18 of 51 (35 per cent) treated with acyclovir twice daily (P less than 0.001 for each regimen compared with placebo). The median time to the first clinical recurrence was 18 days in placebo recipients, compared with over 120 days in both acyclovir-treated groups (P less than 0.001 for both groups compared with placebo). The mean monthly recurrence rate during the medication period was 0.86 in placebo recipients, compared with 0.13 in patients treated with acyclovir five times daily and 0.14 in patients treated with acyclovir twice daily (P less than 0.001 for both groups compared with placebo). While receiving therapy, 86 of 96 acyclovir-treated patients had over a 50 per cent reduction in their pretreatment recurrence rate. Breakthrough recurrences in acyclovir recipients were of shorter duration and associated with a lower frequency of viral shedding than recurrences in placebo recipients. After medication was discontinued, the subsequent recurrence rate returned to pretreatment frequencies. Daily oral acyclovir was well tolerated. We conclude that oral acyclovir given for four months markedly reduces but does not completely prevent recurrences of genital herpes and does not influence the long-term natural history of the disease.