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Tai-nin Chau - One of the best experts on this subject based on the ideXlab platform.
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Conjunctiva-Upper Respiratory Tract Irrigation for Early Diagnosis of Severe Acute Respiratory Syndrome
Journal of clinical microbiology, 2003Co-Authors: Tommy R. Tong, Bosco Hoi-shiu Lam, S. T. Lai, Matthew K. Tong, Tai-nin ChauAbstract:We devised a method for self-obtaining Nasopharyngeal specimens. Patients were given detailed written or verbal instructions. Materials included a 5-ml syringe filled with injectable normal saline, a specimen container, and facial tissues. The process involved the application of normal saline eye drops and expectoration of irrigate that ran into the throat. Anatomically, the conjunctival sac is connected to the nasal cavity by the nasolacrimal duct. Contraction of the palpebral fibers of the orbicularis oculi muscles during blinking opens the normally collapsed, elastic, lacrimal sacs, which return to their collapsed state after blinking; secretions are sucked in through the lacrimal cannaliculi and discharged into the nasolacrimal ducts (1, 2). The mucosal folds in the nasolacrimal ducts ensure one-way traffic to the nose. The lipid content of the meibomian gland secretions makes the lid margins water repellant. Unless too much is applied, the irrigate does not spill from the conjunctival sacs. These anatomical features are exploited in the technique of conjunctiva-upper respiratory tract irrigation (CURTI). With this technique, patients self-apply 1 drop of normal saline per eye at a time. They are asked to blink repeatedly, tilt their heads backward, and sniff to facilitate the drainage of fluid into the nasopharynx. Patients must not swallow the liquid; instead, it should be spat into a specimen container. Patients are told that there is a time lag of up to a minute or two before the fluid begins to run into the throat, and that after one stops applying the eye drops, fluid will continue to run into the throat for a minute or two. Fluid that drains into the throat even after stopping the eye drops should be collected. Specimens reported to be salty were deemed adequate. We tested CURTI with four patients with confirmed severe acute respiratory syndrome (SARS) soon after admission. By using an immunofluorescence assay for SARS coronavirus (4), all patients were found to have seroconverted 13 to 21 days after admission (titer rose from 25 to 200 to 1,600). When real-time PCR (3) and primers Cor-1 and Cor-2 (5) were used, two of the four patients tested positive for the CURTI specimens. By comparison, none of the nose/throat swab (NTS) and stool specimens were positive. Although we cannot compare the sensitivity of CURTI with that of Nasopharyngeal Aspiration (NPA) since the use of NPA was rejected in our hospital, we found CURTI to be more sensitive than NTS in the four patients we studied. Analysis of data (ongoing) revealed an unsatisfactory sensitivity of 60% with NTS in confirmed cases of SARS (based on seroconversion). CURTI, therefore, has a potential sensitivity in excess of 60%. CURTI is simple and well tolerated, as shown by the results with our volunteers. It compares favorably with NPA and NTS in terms of patient comfort and staff safety because it does not provoke sneezing. The CURTI process irrigates the nasopharynx, whereas saliva comes mostly from the three pairs of salivary glands which drain into the anterior oral cavity. Throat gargle does not wash the Nasopharyngeal region because the soft palate is competent in most individuals. If CURTI does have a sensitivity comparable to that of NPA, it should replace NPA because of its enhanced patient comfort and safety.
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Asymptomatic severe acute respiratory syndrome-associated coronavirus infection.
Emerging infectious diseases, 2003Co-Authors: Harold K K Lee, Tai-nin Chau, Eugene Y. K. Tso, Owen T Y Tsang, Kin-wing Choi, Thomas S. T. LaiAbstract:To the Editor: An outbreak of severe acute respiratory syndrome (SARS) began in Hong Kong in March 2003. As of May 29, 2003, a total of 1,732 cases were confirmed; 381 case-patients were healthcare workers and medical students. Clinical features, treatment protocols, and outcomes have been previously reported by various local experts (1–3). The etiologic agent is a SARS-associated coronavirus (SARS-CoV) (1). However, no asymptomatic case of SARS-CoV infection has been previously reported (4). In addition, in Hong Kong, blood donors have not shown any detectable antibody to SARS-CoV (1). We report a case of possible asymptomatic SARS-CoV infection in Hong Kong. The case-patient is a registered nurse working in Princess Margaret Hospital, the major infectious diseases hospital that treated >600 SARS patients in Hong Kong. Within this hospital, >800 frontline staff members have participated in direct care of SARS patients, and SARS developed in 62 of these staff members. All healthcare workers working in SARS wards followed the same infection control measures, wearing a N-95 respirator, eye shield, disposable cap, water-resistant gown, and gloves. Gowns and equipment were removed before the staff left the SARS wards. We performed serologic testing of the first 101 healthcare workers (doctors, nurses, healthcare assistants) who worked in the SARS wards but in whom SARS did not develop. The serologic testing was performed 7–8 weeks after the healthcare workers were first exposed to SARS patients. We identified a nurse who was asymptomatic for SARS-CoV infection, worked in the SARS ward since the disease outbreak, and used full infection control procedures as recommended by the World Health Organization (WHO). The nurse performed procedures, including Nasopharyngeal Aspiration, handling of fecal matter, and oral feeding of SARS patients. SARS developed in six colleagues who worked in the same ward. She had unprotected exposure to a colleague who contracted SARS and required hospitalization. Serologic testing for SARS-CoV antibody was performed in the microbiology laboratory of Princess Margaret Hospital on week 8 of the nurse’s SARS ward duty. The result of the test was positive by enzyme-linked immunosorbent assay. The test was repeated by the Government Virus Unit of the Department of Health, one of the reference laboratories in Hong Kong. The second test also showed a positive result with an antibody titer of 400 by immunofluorescence assay (normal: 37°C and had a leukocyte count of 5.9 x 109/L and a lymphocyte count of 1.6 x 109/L. Results of liver and renal function tests were all normal. Reverse transcription-polymerase chain reaction results for SARS-CoV in stool, urine, throat, and nasal swabs collected during weeks 10 and 14 of her SARS ward duty were all negative. No abnormal radiologic change was identified in the lungs. She lived with four family members and had close contact with them. None of her family members contracted SARS, and all showed a negative result in the serologic testing for SARS-CoV. We think that asymptomatic and subclinical infection of SARS-CoV exists and can result in seroconversion; however, this kind of asymptomatic seroconversion is probably uncommon. Why a person infected with SARS-CoV did not have typical symptoms, and the infectivity of an asymptomatic person is unknown. A person’s genetic makeup may determine susceptibility to SARS-CoV and the final clinical outcome. We agree with Seto et al. (5) that recall bias is a concern. However, recall bias probably had little effect since the events took place recently. Moreover, the hospitalization of the nurse’s infected colleague would have made her more alert and aware of symptoms of the illness.
Thomas S. T. Lai - One of the best experts on this subject based on the ideXlab platform.
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Asymptomatic severe acute respiratory syndrome-associated coronavirus infection.
Emerging infectious diseases, 2003Co-Authors: Harold K K Lee, Tai-nin Chau, Eugene Y. K. Tso, Owen T Y Tsang, Kin-wing Choi, Thomas S. T. LaiAbstract:To the Editor: An outbreak of severe acute respiratory syndrome (SARS) began in Hong Kong in March 2003. As of May 29, 2003, a total of 1,732 cases were confirmed; 381 case-patients were healthcare workers and medical students. Clinical features, treatment protocols, and outcomes have been previously reported by various local experts (1–3). The etiologic agent is a SARS-associated coronavirus (SARS-CoV) (1). However, no asymptomatic case of SARS-CoV infection has been previously reported (4). In addition, in Hong Kong, blood donors have not shown any detectable antibody to SARS-CoV (1). We report a case of possible asymptomatic SARS-CoV infection in Hong Kong. The case-patient is a registered nurse working in Princess Margaret Hospital, the major infectious diseases hospital that treated >600 SARS patients in Hong Kong. Within this hospital, >800 frontline staff members have participated in direct care of SARS patients, and SARS developed in 62 of these staff members. All healthcare workers working in SARS wards followed the same infection control measures, wearing a N-95 respirator, eye shield, disposable cap, water-resistant gown, and gloves. Gowns and equipment were removed before the staff left the SARS wards. We performed serologic testing of the first 101 healthcare workers (doctors, nurses, healthcare assistants) who worked in the SARS wards but in whom SARS did not develop. The serologic testing was performed 7–8 weeks after the healthcare workers were first exposed to SARS patients. We identified a nurse who was asymptomatic for SARS-CoV infection, worked in the SARS ward since the disease outbreak, and used full infection control procedures as recommended by the World Health Organization (WHO). The nurse performed procedures, including Nasopharyngeal Aspiration, handling of fecal matter, and oral feeding of SARS patients. SARS developed in six colleagues who worked in the same ward. She had unprotected exposure to a colleague who contracted SARS and required hospitalization. Serologic testing for SARS-CoV antibody was performed in the microbiology laboratory of Princess Margaret Hospital on week 8 of the nurse’s SARS ward duty. The result of the test was positive by enzyme-linked immunosorbent assay. The test was repeated by the Government Virus Unit of the Department of Health, one of the reference laboratories in Hong Kong. The second test also showed a positive result with an antibody titer of 400 by immunofluorescence assay (normal: 37°C and had a leukocyte count of 5.9 x 109/L and a lymphocyte count of 1.6 x 109/L. Results of liver and renal function tests were all normal. Reverse transcription-polymerase chain reaction results for SARS-CoV in stool, urine, throat, and nasal swabs collected during weeks 10 and 14 of her SARS ward duty were all negative. No abnormal radiologic change was identified in the lungs. She lived with four family members and had close contact with them. None of her family members contracted SARS, and all showed a negative result in the serologic testing for SARS-CoV. We think that asymptomatic and subclinical infection of SARS-CoV exists and can result in seroconversion; however, this kind of asymptomatic seroconversion is probably uncommon. Why a person infected with SARS-CoV did not have typical symptoms, and the infectivity of an asymptomatic person is unknown. A person’s genetic makeup may determine susceptibility to SARS-CoV and the final clinical outcome. We agree with Seto et al. (5) that recall bias is a concern. However, recall bias probably had little effect since the events took place recently. Moreover, the hospitalization of the nurse’s infected colleague would have made her more alert and aware of symptoms of the illness.
Peter J M Openshaw - One of the best experts on this subject based on the ideXlab platform.
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nasosorption as a minimally invasive sampling procedure mucosal viral load and inflammation in primary rsv bronchiolitis
The Journal of Infectious Diseases, 2017Co-Authors: Ryan S Thwaites, Jasmine M S Chingono, Matthew Coates, Hannah C Jarvis, Tanushree Tunstall, Lauren Andersondring, Lindsey Cass, Garth Rapeport, Peter J M Openshaw, Simon NadelAbstract:Background: Existing respiratory mucosal sampling methods are flawed, particularly in a pediatric bronchiolitis setting. Methods: Twenty-four infants with bronchiolitis were recruited: 12 were respiratory syncytial virus (RSV)-positive, 12 were RSV-negative. Infants were sampled by nasosorption and Nasopharyngeal Aspiration (NPA). Results: Nasosorption was well tolerated and identified all RSV+ samples. RSV load measured by nasosorption (but not NPA) correlated with length of hospital stay (P = .04) and requirement for mechanical ventilation (P = .03). Nasosorption (but not NPA) levels of interferon γ, interleukin 1β, CCL5/RANTES, and interleukin 10 (IL-10) were elevated in RSV+ bronchiolitis (all P < .05), furthermore CCL5 and IL-10 correlated with RSV load (P < .05). Conclusions: Nasosorption allowed measurement of RSV load and the mucosal inflammatory response in infants.
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Nasosorption as a Minimally Invasive Sampling Procedure: Mucosal Viral Load and Inflammation in Primary RSV Bronchiolitis.
The Journal of infectious diseases, 2017Co-Authors: Ryan S Thwaites, Jasmine M S Chingono, Matthew Coates, Hannah C Jarvis, Tanushree Tunstall, Lindsey Cass, Garth Rapeport, Kazuhiro Ito, Lauren Anderson-dring, Peter J M OpenshawAbstract:Background Existing respiratory mucosal sampling methods are flawed, particularly in a pediatric bronchiolitis setting. Methods Twenty-four infants with bronchiolitis were recruited: 12 were respiratory syncytial virus (RSV)-positive, 12 were RSV-negative. Infants were sampled by nasosorption and Nasopharyngeal Aspiration (NPA). Results Nasosorption was well tolerated and identified all RSV+ samples. RSV load measured by nasosorption (but not NPA) correlated with length of hospital stay (P = .04) and requirement for mechanical ventilation (P = .03). Nasosorption (but not NPA) levels of interferon γ, interleukin 1β, CCL5/RANTES, and interleukin 10 (IL-10) were elevated in RSV+ bronchiolitis (all P < .05), furthermore CCL5 and IL-10 correlated with RSV load (P < .05). Conclusions Nasosorption allowed measurement of RSV load and the mucosal inflammatory response in infants.
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Nasosorption is a minimally invasive diagnostic procedure for measurement of viral load and markers of mucosal inflammation in RSV bronchiolitis
'Oxford University Press (OUP)', 2017Co-Authors: Rs Thwaites, Ito K, Chingono Jms, Coates M, Hc Jarvis, Tunstall T, Anderson-dring L, Cass L, Rapeport G, Peter J M OpenshawAbstract:Background. Existing respiratory mucosal sampling methods are flawed, particularly in a pediatric bronchiolitis setting. Methods. Twenty-four infants with bronchiolitis were recruited: 12 were respiratory syncytial virus (RSV)–positive, 12 were RSV-negative. Infants were sampled by nasosorption and Nasopharyngeal Aspiration (NPA). Results. Nasosorption was well tolerated and identified all RSV+ samples. RSV load measured by nasosorption (but not NPA) correlated with length of hospital stay (P = .04) and requirement for mechanical ventilation (P = .03). Nasosorption (but not NPA) levels of interferon γ, interleukin 1β, CCL5/RANTES, and interleukin 10 (IL-10) were elevated in RSV+ bronchiolitis (all P < .05), furthermore CCL5 and IL-10 correlated with RSV load (P < .05). Conclusions. Nasosorption allowed measurement of RSV load and the mucosal inflammatory response in infants
Harold K K Lee - One of the best experts on this subject based on the ideXlab platform.
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Asymptomatic severe acute respiratory syndrome-associated coronavirus infection.
Emerging infectious diseases, 2003Co-Authors: Harold K K Lee, Tai-nin Chau, Eugene Y. K. Tso, Owen T Y Tsang, Kin-wing Choi, Thomas S. T. LaiAbstract:To the Editor: An outbreak of severe acute respiratory syndrome (SARS) began in Hong Kong in March 2003. As of May 29, 2003, a total of 1,732 cases were confirmed; 381 case-patients were healthcare workers and medical students. Clinical features, treatment protocols, and outcomes have been previously reported by various local experts (1–3). The etiologic agent is a SARS-associated coronavirus (SARS-CoV) (1). However, no asymptomatic case of SARS-CoV infection has been previously reported (4). In addition, in Hong Kong, blood donors have not shown any detectable antibody to SARS-CoV (1). We report a case of possible asymptomatic SARS-CoV infection in Hong Kong. The case-patient is a registered nurse working in Princess Margaret Hospital, the major infectious diseases hospital that treated >600 SARS patients in Hong Kong. Within this hospital, >800 frontline staff members have participated in direct care of SARS patients, and SARS developed in 62 of these staff members. All healthcare workers working in SARS wards followed the same infection control measures, wearing a N-95 respirator, eye shield, disposable cap, water-resistant gown, and gloves. Gowns and equipment were removed before the staff left the SARS wards. We performed serologic testing of the first 101 healthcare workers (doctors, nurses, healthcare assistants) who worked in the SARS wards but in whom SARS did not develop. The serologic testing was performed 7–8 weeks after the healthcare workers were first exposed to SARS patients. We identified a nurse who was asymptomatic for SARS-CoV infection, worked in the SARS ward since the disease outbreak, and used full infection control procedures as recommended by the World Health Organization (WHO). The nurse performed procedures, including Nasopharyngeal Aspiration, handling of fecal matter, and oral feeding of SARS patients. SARS developed in six colleagues who worked in the same ward. She had unprotected exposure to a colleague who contracted SARS and required hospitalization. Serologic testing for SARS-CoV antibody was performed in the microbiology laboratory of Princess Margaret Hospital on week 8 of the nurse’s SARS ward duty. The result of the test was positive by enzyme-linked immunosorbent assay. The test was repeated by the Government Virus Unit of the Department of Health, one of the reference laboratories in Hong Kong. The second test also showed a positive result with an antibody titer of 400 by immunofluorescence assay (normal: 37°C and had a leukocyte count of 5.9 x 109/L and a lymphocyte count of 1.6 x 109/L. Results of liver and renal function tests were all normal. Reverse transcription-polymerase chain reaction results for SARS-CoV in stool, urine, throat, and nasal swabs collected during weeks 10 and 14 of her SARS ward duty were all negative. No abnormal radiologic change was identified in the lungs. She lived with four family members and had close contact with them. None of her family members contracted SARS, and all showed a negative result in the serologic testing for SARS-CoV. We think that asymptomatic and subclinical infection of SARS-CoV exists and can result in seroconversion; however, this kind of asymptomatic seroconversion is probably uncommon. Why a person infected with SARS-CoV did not have typical symptoms, and the infectivity of an asymptomatic person is unknown. A person’s genetic makeup may determine susceptibility to SARS-CoV and the final clinical outcome. We agree with Seto et al. (5) that recall bias is a concern. However, recall bias probably had little effect since the events took place recently. Moreover, the hospitalization of the nurse’s infected colleague would have made her more alert and aware of symptoms of the illness.
Marcus H Jones - One of the best experts on this subject based on the ideXlab platform.
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Severe lower respiratory tract infection in infants and toddlers from a non-affluent population: viral etiology and co-detection as risk factors
BMC Infectious Diseases, 2013Co-Authors: Emerson Rodrigues Da Silva, Márcio Condessa Paulo Pitrez, Eurico Arruda, Rita Mattiello, Edgar E Sarria, Flávia Escremim De Paula, José Luis Proença-modena, Luana Sella Delcaro, Otávio Cintra, Marcus H JonesAbstract:Background Lower respiratory tract infection (LRTI) is a major cause of pediatric morbidity and mortality, especially among non-affluent communities. In this study we determine the impact of respiratory viruses and how viral co-detections/infections can affect clinical LRTI severity in children in a hospital setting. Methods Patients younger than 3 years of age admitted to a tertiary hospital in Brazil during the months of high prevalence of respiratory viruses had samples collected from Nasopharyngeal Aspiration. These samples were tested for 13 different respiratory viruses through real-time PCR (rt-PCR). Patients were followed during hospitalization, and clinical data and population characteristics were collected during that period and at discharge to evaluate severity markers, especially length of hospital stay and oxygen use. Univariate regression analyses identified potential risk factors and multivariate logistic regressions were used to determine the impact of specific viral detections as well as viral co-detections in relation to clinical outcomes. Results We analyzed 260 episodes of LRTI with a viral detection rate of 85% (n = 222). Co-detection was observed in 65% of all virus-positive episodes. The most prevalent virus was Respiratory Syncytial Virus (RSV) (54%), followed by Human Metapneumovirus (hMPV) (32%) and Human Rhinovirus (HRV) (21%). In the multivariate models, infants with co-detection of HRV + RSV stayed 4.5 extra days (p = 0.004), when compared to infants without the co-detection. The same trends were observed for the outcome of days of supplemental oxygen use. Conclusions Although RSV remains as the main cause of LRTI in infants our study indicates an increase in the length of hospital stay and oxygen use in infants with HRV detected by RT-PCR compared to those without HRV. Moreover, one can speculate that when HRV is detected simultaneously with RSV there is an additive effect that may be reflected in more severe clinical outcome. Also, our study identified a significant number of children infected by recently identified viruses, such as hMPV and Human Bocavirus (HBov), and this is a novel finding for poor communities from developing countries.
