Symptoms and laboratory manifestations of mild COVID-19 in a repatriated cruise ship cohort.

Much of our current understanding about novel coronavirus disease 2019 (COVID-19) comes from hospitalised patients. However, the spectrum of mild and subclinical disease has implications for population-level screening and control. Forty-nine participants were recruited from a group of 99 adults repatriated from a cruise ship with a high incidence of COVID-19. Respiratory and rectal swabs were tested by polymerase chain reaction (PCR) for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Sera were tested for anti-SARS-CoV-2 antibodies by enzyme-linked immunosorbent assay (ELISA) and microneutralisation assay. Symptoms, viral shedding and antibody response were examined. Forty-five participants (92%) were considered cases based on either positive PCR or positive ELISA for immunoglobulin G. Forty-two percent of cases were asymptomatic. Only 15% of symptomatic cases reported fever. Serial respiratory and rectal swabs were positive for 10% and 5% of participants respectively about 3 weeks after median symptom onset. Cycle threshold values were high (range 31-45). Attempts to isolate live virus were unsuccessful. The presence of symptoms was not associated with demographics, comorbidities or antibody response. In closed settings, incidence of COVID-19 could be almost double that suggested by symptom-based screening. Serology may be useful in diagnosis of mild disease and in aiding public health investigations.

The challenge of invasive mosquito vectors in the U.K. during 2016-2018: a summary of the surveillance and control of Aedes albopictus.

Mosquito-borne diseases resulting from the expansion of two key vectors, Aedes aegypti and Aedes albopictus (Diptera: Culicidae), continue to challenge whole regions and continents around the globe. In recent years there have been human cases of disease associated with Chikungunya, dengue and Zika viruses. In Europe, the expansion of Ae. albopictus has resulted in local transmission of Chikungunya and dengue viruses. This paper considers the risk that Ae. aegypti and Ae. albopictus represent for the U.K. and details the results of mosquito surveillance activities. Surveillance was conducted at 34 points of entry, 12 sites serving vehicular traffic and two sites of used tyre importers. The most common native mosquito recorded was Culex pipiens s.l. (Diptera: Culicidae). The invasive mosquito Ae. albopictus was detected on three occasions in southern England (September 2016, July 2017 and July 2018) and subsequent control strategies were conducted. These latest surveillance results demonstrate ongoing incursions of Ae. albopictus into the U.K. via ground vehicular traffic, which can be expected to continue and increase as populations in nearby countries expand, particularly in France, which is the main source of ex-continental traffic.

Laboratory identification of donor-derived coxsackievirus b3 transmission.

Unexpected donor-to-recipient infectious disease transmission is an important, albeit rare, complication of solid organ transplantation. Greater work and understanding about the epidemiology of these donor-derived transmissions is continually required to further mitigate this risk. Herein we present the first reported case of proven donor-derived transmission of coxsackievirus serogroup-3, an enterovirus, following solid organ transplant. Swift and effective communication between the organ donation agency, treating physicians, laboratory testing and notification ensured a coordinated approach. The resulting clinical syndromes in the organ recipients were mild. This case highlights the requirement for ongoing surveillance over a broad range of infecting pathogens that may present as a donor-derived infection.

Longitudinal evaluation of laboratory-based serological assays for SARS-CoV-2 antibody detection.

Serological assays for SARS-CoV-2 infection are now widely available for use in diagnostic laboratories. Limited data are available on the performance characteristics in different settings, and at time periods remote from the initial infection. Validation of the Abbott (Architect SARS-CoV-2 IgG), DiaSorin (Liaison SARS-CoV-2 S1/S2 IgG) and Roche (Cobas Elecsys Anti-SARS-CoV-2) assays was undertaken utilising 217 serum samples from 131 participants up to 7 months following COVID-19 infection. The Abbott and DiaSorin assays were implemented into routine laboratory workflow, with outcomes reported for 2764 clinical specimens. Sensitivity and specificity were concordant with the range reported by the manufacturers for all assays. Sensitivity across the convalescent period was highest for the Roche at 95.2-100% (95% CI 81.0-100%), then the DiaSorin at 88.1-100% (95% CI 76.0-100%), followed by the Abbott 68.2-100% (95% CI 53.4-100%). Sensitivity of the Abbott assay fell from approximately 5 months; on this assay paired serum samples for 45 participants showed a significant drop in the signal-to-cut-off ratio and 10 sero-reversion events. When used in clinical practice, all samples testing positive by both DiaSorin and Abbott assays were confirmed as true positive results. In this low prevalence setting, despite high laboratory specificity, the positive predictive value of a single positive assay was low. Comprehensive validation of serological assays is necessary to determine the optimal assay for each diagnostic setting. In this low prevalence setting we found implementation of two assays with different antibody targets maximised sensitivity and specificity, with confirmatory testing necessary for any sample which was positive in only one assay.

The impact of the pandemic influenza A(H1N1) 2009 virus on seasonal influenza A viruses in the southern hemisphere, 2009.

Data collected over winter 2009 by five World Health Organisation National Influenza Centres in the southern hemisphere were used to examine the circulation of pandemic and seasonal influenza A strains during the first pandemic wave in the southern hemisphere.There is compelling evidence that the pandemic influenza A(H1N1) 2009 virus significantly displaced seasonal influenza A(H1N1) and, to a lesser extent, A(H3N2) viruses circulating in the southern hemisphere. Complete replacement of seasonal influenza A strains, however, was not observed during the first pandemic wave.

A comparative evaluation of the sensitivity of two automated and two manual nucleic acid extraction methods for the detection of norovirus by RT-PCR.

The aim of the study was to compare the sensitivity of a norovirus RT-PCR method using two manual RNA extraction methods (Qiagen and Roche) and two automated RNA extraction methods (Qiagen and Corbett). All four RNA extraction methods gave similar sensitivities although the automated methods, especially the Corbett, required significantly less labour than the manual methods. The automated methods also enabled RNA extraction of approximately two to three times the number of specimens in a given time period compared to manual methods.

Colchicine for acute gout.

BACKGROUND: Gout is one of the most common rheumatic diseases worldwide. Colchicine is regarded as beneficial in the treatment of acute gout, but has a high frequency of gastrointestinal adverse events. OBJECTIVES: To evaluate the efficacy and safety of colchicine for relief of the signs and symptoms of acute gouty arthritis, compared to placebo and other treatment interventions. SEARCH STRATEGY: We searched the following electronic databases to March 2006: Cochrane Central Register of Controlled Trials (CENTRAL, Issue 1, 2006), MEDLINE (from 1966), EMBASE (from 1980), CINAHL (from 1982), AMED (from 1985), Web of Science (from 1945) and Current Controlled Trials. SELECTION CRITERIA: Published randomised controlled trials (RCTs) and controlled clinical trials evaluating symptom relief and adverse outcomes of colchicine therapy in acute gout were considered for this review. DATA COLLECTION AND ANALYSIS: Two reviewers independently screened search results for inclusion, collected the data in a standardized form and assessed the methodological quality of the trial using validated criteria. Results for continuous outcome measures were expressed as weighted mean differences. Dichotomous outcome measures were pooled using relative risk. The number needed to treat was calculated for significant outcomes. MAIN RESULTS: One RCT (N=43) comparing colchicine to placebo for the treatment of acute gout was included in this review. The results favour the use of colchicine over placebo with an absolute reduction of 34% for pain and a 30% reduction in clinical symptoms such as tenderness on palpation, swelling, redness, and pain. The number needed to treat (NNT) with colchicine versus placebo to reduce pain was 3 and the NNT to reduce clinical symptoms was 2. All participants treated with colchicine experienced gastrointestinal side effects (diarrhea and/or vomiting) and the number needed to harm (NNH) with colchicine versus placebo was 1. No studies comparing colchicine to NSAIDs or other treatments such as corticosteroids or ACTH were identified. AUTHORS' CONCLUSIONS: Colchicine is an effective treatment for the reduction of pain and clinical symptoms in patients experiencing acute attacks of gout, although in the regimen studied its low benefit to toxicity ratio limits its usefulness. It should be used as a second line therapy when NSAIDs or corticosteroids are contraindicated or ineffective. More evidence is needed to compare the efficacy of colchicine to that of NSAIDs or corticosteroids, the current first line therapy for acute gout.

Acetaminophen for osteoarthritis.

BACKGROUND: Osteoarthritis (OA) is the most common form of arthritis. Published guidelines and expert opinion are divided over the relative role of acetaminophen (also called paracetamol or Tylenol) and non-steroidal anti-inflammatory drugs (NSAIDs) as first-line pharmacologic therapy. The comparative safety of acetaminophen and NSAIDs is also important to consider. This update to the original 2003 review includes nine additional RCTs. OBJECTIVES: To assess the efficacy and safety of acetaminophen versus placebo and versus NSAIDs (ibuprofen, diclofenac, arthrotec, celecoxib, naproxen, rofecoxib) for treating OA. SEARCH STRATEGY: We searched MEDLINE (up to July 2005), EMBASE (2002-July 2005), Cochrane Central Register of Controlled Trials (CENTRAL), ACP Journal Club, DARE, Cochrane Database of Systematic Reviews (all from 1994 to July 2005). Reference lists of identified RCTs and pertinent review articles were also hand searched. SELECTION CRITERIA: Published randomized controlled trials (RCTs) evaluating the efficacy and safety of acetaminophen alone in OA were considered for inclusion. DATA COLLECTION AND ANALYSIS: Pain, physical function and global assessment outcomes were reported. Results for continuous outcome measures were expressed as standardized mean differences (SMD). Dichotomous outcome measures were pooled using relative risk (RR) and the number needed to treat (NNT) was calculated. MAIN RESULTS: Fifteen RCTs involving 5986 participants were included in this review. Seven RCTs compared acetaminophen to placebo and ten RCTs compared acetaminophen to NSAIDs. In the placebo-controlled RCTs, acetaminophen was superior to placebo in five of the seven RCTs and had a similar safety profile. Compared to placebo, a pooled analysis of five trials of overall pain using multiple methods demonstrated a statistically significant reduction in pain (SMD -0.13, 95% CI -0.22 to -0.04), which is of questionable clinical significance. The relative percent improvement from baseline was 5% with an absolute change of 4 points on a 0 to 100 scale. The NNT to achieve an improvement in pain ranged from 4 to 16. In the comparator-controlled RCTs, acetaminophen was less effective overall than NSAIDs in terms of pain reduction, global assessments and in terms of improvements in functional status. No significant difference was found overall between the safety of acetaminophen and NSAIDs, although patients taking traditional NSAIDS were more likely to experience an adverse GI event (RR 1.47, (95% CI 1.08 to 2.00). 19% of patients in the traditional NSAID group versus 13% in the acetaminophen group experienced an adverse GI event. However, the median trial duration was only 6 weeks and it is difficult to assess adverse outcomes in a relatively short time period. AUTHORS' CONCLUSIONS: The evidence to date suggests that NSAIDs are superior to acetaminophen for improving knee and hip pain in people with OA. The size of the treatment effect was modest, and the median trial duration was only six weeks, therefore, additional considerations need to be factored in when making the decision between using acetaminophen or NSAIDs. In OA subjects with moderate-to-severe levels of pain, NSAIDs appear to be more effective than acetaminophen.

Virological diagnosis of Ebolavirus infection.

Ebolaviruses, and the other viral causes of haemorrhagic fevers (VHF) have always posed special problems for diagnostic laboratories. These arise from the rarity of human infections, minimal documented experience with test delivery and interpretation, the paucity of established commercial or in-house assays, the lack of clinical material for test development and validation, the high level containment required for handling live virus, the ongoing evolution of the viruses, and the high personal and public health requirements for accurate diagnosis. This article addresses the current situation and the ongoing challenges associated with delivering timely, high quality and safe testing within Australia for people exposed as part of the current major outbreak of Ebolavirus disease (EVD) in Western Africa. The members of the Public Health Laboratory Network have developed deliverable and reliable nucleic acid detection tests, and also have the laboratory capacity to handle the live viruses if necessary. However delivering and maintaining these services necessitates high levels of experience in developing and applying tests for exotic and emerging infections, strong national and international links and collaborations, ongoing monitoring and reassessment of test design and performance, innovative approaches to generation of positive control material, and a regular quality assurance program.

Receptor binding sites for cholecystokinin, galanin, somatostatin, substance P and vasoactive intestinal polypeptide in sympathetic ganglia.

Sympathetic ganglia are innervated by neuropeptide-containing fibers originating from pre- and postganglionic sympathetic neurons, dorsal root ganglion neurons, and in some cases, myenteric neurons. In the present report receptor autoradiography was used to determine whether sympathetic ganglia express receptor binding sites for several of these neuropeptides including bombesin, calcitonin gene-related peptide-alpha, cholecystokinin, galanin, neurokinin A, somatostatin, substance P, and vasoactive intestinal polypeptide. The sympathetic ganglia examined included the rat and rabbit superior cervical ganglia and the rabbit superior mesenteric ganglion. High levels of receptor binding sites for cholecystokinin, galanin, somatostatin, substance P, and vasoactive intestinal polypeptide were observed in all sympathetic ganglia examined, although only discrete neuronal populations within each ganglion appeared to express receptor binding sites for any particular neuropeptide. These data suggest that discrete populations of postganglionic sympathetic neurons may be regulated by neuropeptides released from pre- and postganglionic sympathetic neurons, dorsal root ganglion neurons, and myenteric neurons.

Intra-arterial infusion of [125I]A beta 1-40 labels amyloid deposits in the aged primate brain in vivo.

Alzheimer's disease is characterized by extracellular amyloid deposits in the brain at both vascular sites (cerebrovascular amyloid, CVA) and within the neuropil (plaques). In the present study we demonstrated that brain amyloid of aged non-human primates is efficiently detected by [125I]A beta in vitro, and assessed the detection of that amyloid in vivo by intravascular infusion of [125I]A beta. Aged squirrel monkeys (Saimiri sciureus) were anesthetized and infused intra-arterially with [125I]A beta, and sacrificed 2 h later. Analysis of the anterior frontal and temporal cortices by autoradiography demonstrated that [125I]A beta was deposited on CVA and that essentially every amyloid deposit which could be detected with thioflavin S or anti-A beta antibodies was also labeled by [125I]A beta. These experiments suggest that intravascular infusion of radiolabeled A beta can be used to detect and image amyloid deposits in the human AD brain.

High levels of mRNA coding for substance P, somatostatin and alpha-tubulin are expressed by rat and rabbit dorsal root ganglia neurons.

Oligonucleotide probes complementary to alpha-tubulin, preprotachykinin A (PPT A), preprosomatostatin (PPSOM), and preproarginine-vasopressin (PPAVP) mRNA were hybridized to sections of rat and rabbit brain and dorsal root ganglia (DRG) at all spinal levels. Approximately 100% of the DRG neurons in the rat and rabbit express alpha-tubulin mRNA, 20-30% express PPT A mRNA and 5-17% express PPSOM mRNA. Whereas neurons which express PPSOM mRNA are of relative uniform size, the neurons which express PPT A mRNA segregate into two broad groups. One group is composed of smaller neurons (200-2,000 microns 2) which contain an extremely dense concentration of PPT A mRNA. The second group is composed of larger neurons (2,000-3,500 microns 2) which contain a moderate concentration of PPT A mRNA. PPAVP mRNA is present in very high concentrations in the paraventricular and supraoptic nucleus of the rat hypothalamus but is not detected in any DRG neurons. In both the rat and the rabbit the density of PPT A and PPSOM mRNA is high in individual DRG neurons in comparison to PPT A and PPSOM mRNA levels contained in most forebrain neurons. These results suggest that although the level of neuropeptide present in DRG neurons is relatively low in comparison to other brain areas, the rate of sensory neuropeptide synthesis and turnover, as reflected by mRNA content, is extremely high.

Receptors for sensory neuropeptides in human inflammatory diseases: implications for the effector role of sensory neurons.

Glutamate and several neuropeptides are synthesized and released by subpopulations of primary afferent neurons. These sensory neurons play a role in regulating the inflammatory and immune responses in peripheral tissues. Using quantitative receptor autoradiography we have explored what changes occur in the location and concentration of receptor binding sites for sensory neurotransmitters in the colon in two human inflammatory diseases, ulcerative colitis and Crohn's disease. The sensory neurotransmitter receptors examined included bombesin, calcitonin gene related peptide-alpha, cholecystokinin, galanin, glutamate, somatostatin, neurokinin A (substance K), substance P, and vasoactive intestinal polypeptide. Of the nine receptor binding sites examined only substance P binding sites associated with arterioles, venules and lymph nodules were dramatically up-regulated in the inflamed tissue. These data suggest that substance P is involved in regulating the inflammatory and immune responses in human inflammatory diseases and indicate a specificity of efferent action for each sensory neurotransmitter in peripheral tissues.

Multiple outbreaks of Norwalk-like virus gastro-enteritis associated with a Mediterranean-style restaurant.

The role of diverse infectious agents, particularly Norwalk-like viruses (NLV), in three successive gastro-enteritis outbreaks in one setting (a restaurant) was evaluated. Methods included standard bacteriological tests, specific tests for Escherichia coli, tests for verocytotoxins, electron microscopy (EM) for viruses and reverse transcription-PCR (RT-PCR) methodology for NLV. No pathogenic bacteria were detected. Verocytotoxin genes, although detected by PCR in the first outbreak, could not be confirmed in the E. coli isolated, so they did not appear to be of significance. NLV was the main agent detected in each of the three outbreaks. DNA sequencing and phylogenetic analysis of the amplified products obtained from the RT-PCR positive specimens indicated that only one NLV strain was involved in each outbreak, but the NLV strains responsible for the three outbreaks were different from each other. PCR technology for detection of NLV proved highly sensitive, but failed to detect one specimen which was positive by EM. The restaurant associated with the outbreaks is a Mediterranean-style restaurant where food from a common platter is typically eaten with fingers. The findings indicate that NLV was introduced by guests or staff and was not due to a long-term reservoir within the setting.

High level excretion of Norwalk-like virus following resolution of clinical illness.

We report the case of an elderly woman excreting high levels (about 5 x 10(5) virions per gram of faeces) of Norwalk-like virus (NLV) in the absence of any clinical symptoms of gastroenteritis. Analysis by reverse transcription, polymerase chain reaction and DNA sequencing was carried out on a 342-nucleotide region of open reading frame 1. This indicated that the NLV belonged to genogroup 2 and was more closely related to the Camberwell subgroup, the most common circulating in southeast Australia at present, than to the Norwalk and Mexico viruses.

Diagnosis of enteric pathogens in children with gastroenteritis.

The aim of this study was to determine the isolation trends of common and emerging pathogens in children over a 12-month period. The study group included 412 children under 6 years with diarrhoea who were either hospitalised, or seen in the outpatients department of The Sydney Children's Hospital. Pathogens were detected in 137 (33%) samples, with rotavirus most common (40%), followed by adenovirus (26%), astrovirus (12%), Campylobacter jejuni (12%), Salmonella spp. (10%) and Giardia lamblia (< 1 %). Giardia-specific antigen (GSA) was detected in 11 of 382 (3%) using an enzyme immunoassay (EIA), and this included four samples in which cysts of G. lamblia were detected by microscopy. Using electron microscopy (EM), viruses were detected in 29 of 120 (24%) samples from hospitalised children and 53 of 171 (31%) outpatients (P = 0.23). Amongst this subset, Norwalk-like viruses (NLVs) were detected by RT-PCR in 10 samples including six of 14 with small round viruses, one of seven with small viral-like particles (SVLPs), and three of 126 EM-negative samples. Lactoferrin, detected by EIA, was 59% more likely to be positive in samples infected with salmonella/campylobacter than in samples in which bacterial pathogens were not isolated. As an indicator for infection with these bacterial agents, the assay showed a sensitivity and specificity of 95 and 40.3%, respectively. A routine microbiological analysis of stools from children of this age group should include a screen for foodborne bacterial agents and rotavirus. Tests for adenovirus, astrovirus and NLVs should be secondary. The cost-effectiveness of including the EIAs for lactoferrin and G. lamblia in the routine testing protocol needs to be evaluated.

Alterations in receptors for sensory neuropeptides in human inflammatory bowel disease.

Glutamate and several neuropeptides are synthesized and released by subpopulations of primary afferent neurons. These sensory neurons play a role in regulating the inflammatory and immune responses in peripheral tissues. We have explored what changes occur in the location and concentration of receptor binding sites for sensory neurotransmitters in two human inflammatory diseases, ulcerative colitis and Crohn's disease, using quantitative receptor autoradiography. The sensory neurotransmitter receptors included bombesin, calcitonin gene-related peptide-alpha, cholecystokinin, galanin, glutamate, somatostatin, neurokinin A (substance K), substance P, and vasoactive intestinal polypeptide. Of the nine receptor binding sites examined only binding sites for substance P and vasoactive intestinal peptide were significantly altered in the inflamed tissue. These data suggest that substance P is involved in regulating the inflammatory and immune responses in human inflammatory diseases and indicate a specificity of efferent action for each sensory neurotransmitter in peripheral tissues.

Virological aspects of human immunodeficiency virus infection.

The virology of human immunodeficiency virus (HIV) infection is reviewed. The transmission of HIV is restricted to direct contact with the blood or other body fluids of infected human beings. Ordinary social contact with infected individuals holds no risk but in the health care setting all patients must be considered to be potentially infectious and universal precautions taken. The replication of HIV in cells of the immune system carrying the CD4 receptor creates a complex relationship between the virus infection and the host immune response. The pathogenesis and the principles of the laboratory diagnosis of HIV infection are reviewed. Since its discovery HIV has quickly become one of the most studied and best characterized of human pathogens. The diagnosis of HIV infection, because of its implications, has been made more accurate than for any other infection. This understanding has significantly improved treatment but has yet to provide curative therapy, and prevention of infection is still the basis of the fight against AIDS.

PIP: HIV can be acquired only through direct contact with the blood or other body fluids of infected individuals. There is therefore no risk of contracting or transmitting HIV through normal social contact with HIV-infected individuals. However, in health care settings, universal precautions must be applied with all patients under the assumption that they could be infected with HIV and are therefore infectious. The virology of HIV infection is reviewed in sections on virology, transmission, life cycle, pathogenesis, and laboratory diagnosis. The diagnosis of HIV infection is more accurate than for any other infection, reflecting the importance of HIV as an infectious agent and the implications of infection. While treatment against HIV and AIDS has improved, curative therapy remains to be developed. Preventing HIV infection therefore remains the central strategy against AIDS.