ABSTRACT
INTRODUCTION: Plasma phosphorylated tau (p-tau)217 is a promising biomarker for Alzheimer's disease (AD) diagnosis, but its clinical implementation remains challenging. We propose a strategy based on Bayes' theorem and test it in real-life memory clinics. METHODS: Memory clinic patients were evaluated by neurocognitive specialists for prespecified diagnosis and subsequently underwent blood collection for p-tau217, cerebrospinal fluid, or amyloid positron emission tomography. Using cross-validation, the Bayesian approach (pretest probability × individualized likelihood ratio) was compared to other models for AD diagnosis. RESULTS: The Bayesian strategy demonstrated an area under the receiver operating characteristic curve (AUC) of 0.98 (95% confidence interval [CI]: 0.96-1.0), significantly outperforming multivariable logistic regression (p-tau217, age, apolipoprotein E; AUC 0.95, p = 0.024) and p-tau217 alone (AUC = 0.94, p = 0.007). When applying the two-threshold approach, the Bayesian strategy yielded an accuracy of 0.94 (95% CI: 0.88-1.0) without requiring confirmatory tests in 62.9% of the iterations. DISCUSSION: The Bayesian strategy offers an effective and flexible approach to address the limitations of plasma p-tau217 in clinical practice. HIGHLIGHTS: Incorporating pretest probability into the interpretation of plasma phosphorylated tau (p-tau)217 improves the diagnostic performance significantly. The strategy could obviate the need for confirmatory testing in most of the patients. Plasma p-tau217 proves useful as a biomarker for Alzheimer's disease in low- and middle-income country such as Thailand.
ABSTRACT
The lack of a dedicated surveillance program for prion disease, particularly in low- and middle-income countries (LMICs), has hindered the global effort to address this public health threat. Although cerebrospinal fluid (CSF) Real-time quaking-induced conversion (RT-QuIC) is considered the most reliable test for sporadic Creutzfeldt-Jakob disease (sCJD), its availability in LMICs is limited because of its cost and technical difficulty in generating the recombinant prion protein substrate (recPrP). This study aimed to evaluate the performance of RT-QuIC with recPrP produced in-house through a small-scale method-that is, the application of reusable prepacked chromatography columns and subsequent dialysis. Here, CSF specimens from patients suspected of having prion disease were consecutively collected and stored between October 2015 and January 2023. Electronic medical record data were reviewed to clinically classify participants as probable sCJD or non-sCJD. CSF RT-QuIC was performed using in-house recPrP. Its specificity and sensitivity for diagnosing probable sCJD were reported, along with details of other clinical data and investigations. We found that among 39 eligible participants, with a median (interquartile range) age of 64 (56-70) years and 16 (41%) female, 13 had probable sCJD and the remaining 26 unequivocally suffered from nonprion disorders. Magnetic resonance imaging and electroencephalogram were suggestive of sCJD in 100% (13/13) and 46.2% (6/13) of sCJD participants, respectively. RT-QuIC was positive in 12/13 sCJD participants (sensitivity 0.92, 95% confidence interval [CI] 0.67-0.99) and negative in all non-sCJD participants (specificity 1.00, 95% CI 0.87-1.00). CSF tau/p-tau ratio showed sensitivity and specificity of 0.62-1.0 and 0.85-1.0, respectively. In summary, RT-QuIC using recPrP generated through a small-scale workflow demonstrated great performance in detecting sCJD. Given its performance results along with its low cost, this technique could feasibly be implemented in LMICs and potentially be the first step toward establishing local prion disease surveillance programs.
Subject(s)
Creutzfeldt-Jakob Syndrome , Prion Diseases , Prions , Humans , Female , Middle Aged , Aged , Male , Creutzfeldt-Jakob Syndrome/diagnosis , Creutzfeldt-Jakob Syndrome/cerebrospinal fluid , Creutzfeldt-Jakob Syndrome/pathology , Workflow , Prion Proteins , Sensitivity and SpecificityABSTRACT
INTRODUCTION: Despite the substantial accuracy of plasma p-tau in diagnosing Alzheimer's disease (AD) in research cohorts, data on real-life memory clinic patients are lacking. METHODS: Memory clinic patients at their early symptomatic stages were prospectively enrolled to undergo routine clinical assessment, plasma p-tau181 quantification (Simoa), amyloid and tau-positron emission tomography (PET). The diagnostic performance of plasma p-tau181, neurocognitive specialists, and regional tau-PET were compared head-to-head using amyloid-PET as the reference standard. RESULTS: Plasma p-tau181 has the area under the curve (AUC), sensitivity, specificity, and accuracy of 0.84 (95% confidence interval [CI] 0.73-0.94), 0.80 (95% CI 0.64-0.90), 0.75 (95% CI 0.51-0.90), and 0.78 (95% CI 0.65-0.88) for detecting amyloid-PET positivity in early symptomatic patients, respectively. The AUC of clinical diagnosis and tau-PET were 0.70 (95% CI 0.56-0.85) and 0.88 (95% CI 0.79-0.97), respectively. DISCUSSION: Plasma p-tau181 also performed well in real-life memory clinic settings and its role in clinical practice is supported.
Subject(s)
Alzheimer Disease , tau Proteins , Humans , Amyloid beta-Peptides , Thailand , Biomarkers , Alzheimer Disease/diagnostic imagingABSTRACT
BACKGROUND: We report the first case of COVID-19 associated acute necrotizing encephalopathy (ANE) without pulmonary disease in a patient with an extremely high interleukin-6 (IL-6) level and Ran Binding Protein 2 (RANBP2) mutation. CASE PRESENTATION: A 29-year-old woman recently immunized with inactivated viral vaccine-BBIBP32-CorV (Sinopharm) presented with alteration of consciousness. Her body temperature was 37° Celsius, blood pressure 42/31 mmHg, heart rate 130 bpm, respiratory rate 20 per minute, and oxygen saturation 98%. Respiratory examination was unremarkable. Neurological examination revealed stupor but preserved brainstem reflexes. Non-contrast computerized tomography of the brain showed symmetrical hypodense lesions involving bilateral thalami and cerebellar hemispheres characteristic of ANE. No pulmonary infiltration was found on chest radiograph. SARS-CoV-2 was detected by PCR; whole genome sequencing later confirmed the Delta variant. RANBP2 gene analysis revealed heterozygous Thr585Met mutation. Serum IL-6 was 7390 pg/mL. Urine examination showed pyelonephritis. Her clinical course was complicated by seizure, septic shock, acute kidney injury, and acute hepatic failure. She later developed coma and passed away in 6 days. CONCLUSIONS: ANE is caused by cytokine storm leading to necrosis and hemorrhage of the brain. IL-6 was deemed as a prognostic factor and a potential treatment target of ANE in previous studies. RANBP2 missense mutation strongly predisposes this condition by affecting mitochondrial function, viral entry, cytokine signaling, immune response, and blood-brain barrier maintenance. Also, inactivated vaccine has been reported to precipitate massive production of cytokines by antibody dependent enhancement (ADE). The true incidence of COVID-19 associated ANE is not known as were the predictors of its development. We proposed these potential two factors (RANBP2 mutation and ADE) that could participate in the pathogenesis of ANE in COVID-19 apart from SARS-CoV2 infection by itself. Further study is needed to confirm this hypothesis, specifically in the post-vaccination period. Role of RANBP2 mutation and its application in COVID-19 and ANE should be further elaborated.
Subject(s)
Brain Diseases , COVID-19 , Leukoencephalitis, Acute Hemorrhagic , Adult , Brain Diseases/complications , Female , Humans , Interleukin-6/genetics , Leukoencephalitis, Acute Hemorrhagic/diagnosis , Leukoencephalitis, Acute Hemorrhagic/genetics , Molecular Chaperones , Mutation , Nuclear Pore Complex Proteins , RNA, Viral , SARS-CoV-2/genetics , Vaccines, Inactivated/therapeutic useABSTRACT
BACKGROUND: Interactions between humans and animals are the key elements of zoonotic spillover leading to zoonotic disease emergence. Research to understand the high-risk behaviors associated with disease transmission at the human-animal interface is limited, and few consider regional and local contexts. OBJECTIVE: This study employed an integrated behavioral-biological surveillance approach for the early detection of novel and known zoonotic viruses in potentially high-risk populations, in an effort to identify risk factors for spillover and to determine potential foci for risk-mitigation measures. METHOD: Participants were enrolled at two community-based sites (n = 472) in eastern and western Thailand and two hospital (clinical) sites (n = 206) in northeastern and central Thailand. A behavioral questionnaire was administered to understand participants' demographics, living conditions, health history, and animal-contact behaviors and attitudes. Biological specimens were tested for coronaviruses, filoviruses, flaviviruses, influenza viruses, and paramyxoviruses using pan (consensus) RNA Virus assays. RESULTS: Overall 61/678 (9%) of participants tested positive for the viral families screened which included influenza viruses (75%), paramyxoviruses (15%), human coronaviruses (3%), flaviviruses (3%), and enteroviruses (3%). The most salient predictors of reporting unusual symptoms (i.e., any illness or sickness that is not known or recognized in the community or diagnosed by medical providers) in the past year were having other household members who had unusual symptoms and being scratched or bitten by animals in the same year. Many participants reported raising and handling poultry (10.3% and 24.2%), swine (2%, 14.6%), and cattle (4.9%, 7.8%) and several participants also reported eating raw or undercooked meat of these animals (2.2%, 5.5%, 10.3% respectively). Twenty four participants (3.5%) reported handling bats or having bats in the house roof. Gender, age, and livelihood activities were shown to be significantly associated with participants' interactions with animals. Participants' knowledge of risks influenced their health-seeking behavior. CONCLUSION: The results suggest that there is a high level of interaction between humans, livestock, and wild animals in communities at sites we investigated in Thailand. This study highlights important differences among demographic and occupational risk factors as they relate to animal contact and zoonotic disease risk, which can be used by policymakers and local public health programs to build more effective surveillance strategies and behavior-focused interventions.
Subject(s)
Communicable Diseases, Emerging , Animals , Animals, Wild , Cattle , Communicable Diseases, Emerging/epidemiology , Humans , Poultry , Swine , Thailand/epidemiology , Zoonoses/epidemiologyABSTRACT
In early January 2020, Thailand became the first country where a coronavirus disease 2019 (COVID-19) patient was identified outside China. In this study, 23 whole genomes of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) from patients who were hospitalized from January to March 2020 were analyzed, along with their travel histories. Six lineages were identified including A, A.6, B, B.1, B.1.8, and B.58, among which lineage A.6 was dominant. Seven patients were from China who traveled to Thailand in January and early February. Five of them were infected with the B lineage virus, and the other two cases were infected with different lineages including A and A.6. These findings present clear evidence of the early introduction of diverse SARS-CoV-2 clades in Thailand.
Subject(s)
COVID-19 , SARS-CoV-2 , China , Genome, Viral , Humans , ThailandABSTRACT
In the age of a pandemic, such as the ongoing one caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the world faces a limited supply of tests, personal protective equipment, and factories and supply chains are struggling to meet the growing demands. This study aimed to evaluate the efficacy of specimen pooling for testing of SARS-CoV-2 virus, to determine whether costs and resource savings could be achieved without impacting the sensitivity of the testing. Ten previously tested nasopharyngeal and throat swab specimens by real-time polymerase chain reaction (PCR), were pooled for testing, containing either one or two known positive specimens of varying viral concentrations. Specimen pooling did not affect the sensitivity of detecting SARS-CoV-2 when the PCR cycle threshold (Ct) of original specimen was lower than 35. In specimens with low viral load (Ct > 35), 2 of 15 pools (13.3%) were false negative. Pooling specimens to test for Coronavirus Disease 2019 infection in low prevalence (≤1%) areas or in low risk populations can dramatically decrease the resource burden on laboratory operations by up to 80%. This paves the way for large-scale population screening, allowing for assured policy decisions by governmental bodies to ease lockdown restrictions in areas with a low incidence of infection, or with lower-risk populations.
Subject(s)
COVID-19 Testing/methods , COVID-19/diagnosis , COVID-19/epidemiology , Pandemics , Real-Time Polymerase Chain Reaction/methods , SARS-CoV-2/genetics , Specimen Handling/methods , COVID-19/economics , COVID-19/virology , COVID-19 Testing/economics , Disease Notification/economics , Disease Notification/methods , Epidemiological Monitoring , Humans , Limit of Detection , Nasopharynx/virology , Pharynx/virology , Prevalence , RNA, Viral/genetics , Real-Time Polymerase Chain Reaction/economics , Retrospective Studies , Specimen Handling/economics , Thailand/epidemiology , Viral LoadABSTRACT
BACKGROUND: The incidence of autoimmune encephalitis has risen globally. There are two general categories of disease-associated antibodies that can be tested for: neuronal surface and intracellular. However, testing both groups of autoantibodies are costly. This study aims to identify differences between groups by comparing clinical presentations, radiological findings and CSF profile of patients, and determine if any parameters are indicative of one group of autoantibodies over another. Additionally, we aim to report the local incidence of less common groups of disease-associated antibodies as well. METHODS: Seventy-seven records of autoimmune encephalitis/encephalomyelitis patients admitted to King Chulalongkorn Memorial Hospital, Bangkok, Thailand, between October 2010 and February 2017 were reviewed. Patients with infections or those with classic central nervous system demyelinating features were excluded. RESULTS: Of 77 patients, 40% presented with neuronal surface antibodies and 33% had intracellular antibodies. The most common autoantibody detected in each group was anti-NMDAr antibody (25/31, 81%) and anti-Ri antibody (7/25, 28%) respectively. In the neuronal surface antibody group, behavioral change was the most common complaint (45%), followed by seizures (39%) and abnormal movements (29%). In the latter group, seizure was the most common presenting symptom (32%), followed by motor weakness (20%), behavioural change (16%) and abnormal movements (16%). Patients with neuronal surface antibodies were younger (35 vs 48 years old, p = 0.04) and more likely to present with behavioral change (45% vs 16%, p = 0.02). Mortality rate was higher in the intracellular group (16% vs 3.2%, p = 0.09). No differences were detected in magnetic resonance imaging (MRI) and CSF profile. CONCLUSIONS: In the early stages of the disease, both groups have comparable clinical outcomes. Although there were significant differences in age and percentage of patients with behavioral change, both groups of autoimmune encephalitis still shared many clinical features and could not be distinguished based on MRI and CSF profiles. Therefore, we recommend that patients with features of autoimmune encephalitis should be screened for both the neuronal surface and intracellular antibodies regardless of clinical presentation.
Subject(s)
Encephalitis , Hashimoto Disease , Adult , Autoantibodies/cerebrospinal fluid , Encephalitis/cerebrospinal fluid , Encephalitis/classification , Encephalitis/diagnostic imaging , Encephalitis/immunology , Hashimoto Disease/cerebrospinal fluid , Hashimoto Disease/classification , Hashimoto Disease/diagnostic imaging , Hashimoto Disease/immunology , Humans , Magnetic Resonance Imaging , Middle Aged , Tertiary Care Centers , ThailandABSTRACT
PURPOSE OF REVIEW: Despite great progress in decoding disease mechanisms, rabies remains one of the leading causes of human death worldwide. Towards the elimination of human rabies deaths by 2030, feasible and affordable post (PEP) and pre-exposure prophylaxis (PrEP) must be available with expansion to rural areas in rabies endemic countries. Vaccination and population control of dogs, principal reservoirs and transmitters, must be done in concert. RECENT FINDING: Advances in the understanding of rabies neuropathogenesis and pathophysiology are reviewed, including recent experimental findings on host- and virus-specific mechanisms mediating neuronal survival and explaining clinical differences in furious and paralytic rabies. The forthcoming World Health Organization guide on rabies based on pathogenesis and immunization mechanisms data with support by clinical evidence provide new accelerated 1 week intradermal PrEP and PEP schedules. Rabies immunoglobulin injected into the wound only is endorsed at amounts not exceeding the dose interfering with active immunization. Potential therapeutics as designed in accord with rabies neuro-pathophysiology are plausible. SUMMARY: Clinical practice and rabies awareness can be leveraged by transboundary collaboration among different areas. Advancement in prophylaxis and perspectives on animal control offer a new path to conquer rabies by 2030.
Subject(s)
Disease Transmission, Infectious/prevention & control , Post-Exposure Prophylaxis/methods , Pre-Exposure Prophylaxis/methods , Rabies/prevention & control , Rabies/physiopathology , Zoonoses/prevention & control , Animals , Disease Eradication/trends , Dogs , Host-Pathogen Interactions , HumansABSTRACT
BACKGROUND: Bats are natural reservoirs for several highly pathogenic and novel viruses including coronaviruses (CoVs) (mainly Alphacoronavirus and Betacoronavirus). Lyle's flying fox (Pteropus lylei)'s roosts and foraging sites are usually in the proximity to humans and animals. Knowledge about age-specific pattern of CoV infection in P. lylei, prevalence, and viral shedding at roosts and foraging sites may have an impact on infection-age-structure model to control CoV outbreak. METHODS: P. lylei bats were captured monthly during January-December 2012 for detection of CoV at three areas in Chonburi province; two human dwellings, S1 and S2, where few fruit trees were located with an open pig farm, 0.6 km and 5.5 km away from the bat roost, S3. Nested RT-PCR of RNA-dependent RNA polymerase (RdRp) gene from rectal swabs was used for CoV detection. The strain of CoV was confirmed by sequencing and phylogenetic analysis. RESULTS: CoV infection was found in both juveniles and adult bats between May and October (January, in adults only and April, in juveniles only). Of total rectal swab positives (68/367, 18.5%), ratio was higher in bats captured at S1 (11/44, 25.0%) and S2 (35/99, 35.4%) foraging sites than at roost (S3) (22/224, 9.8%). Juveniles (forearm length ≤ 136 mm) were found with more CoV infection than adults at all three sites; S1 (9/24, 37.5% vs 2/20, 10%), S2 (22/49, 44.9% vs 13/50, 26.0%), and S3 (10/30, 33.3% vs 12/194, 6.2%). The average BCI of CoV infected bats was significantly lower than uninfected bats. No gender difference related to infection was found at the sites. Phylogenetic analysis of conserved RdRp gene revealed that the detected CoVs belonged to group D betacoronavirus (n = 64) and alphacoronavirus (n = 4). CONCLUSIONS: The fact that CoV infection and shedding was found in more juvenile than adult bats may suggest transmission from mother during peripartum period. Whether viral reactivation during parturition period or stress is responsible in maintaining transmission in the bat colony needs to be explored.
Subject(s)
Animal Diseases/epidemiology , Animal Diseases/virology , Chiroptera/virology , Coronavirus Infections/veterinary , Coronavirus , Age Factors , Animals , Coronavirus/genetics , Female , Genome, Viral , Longitudinal Studies , Male , Phylogeny , Prevalence , RNA, Viral , Thailand/epidemiology , Virus SheddingABSTRACT
Thailand reported the first Middle East respiratory syndrome (MERS) case on 18 June 2015 (day 4) in an Omani patient with heart condition who was diagnosed with pneumonia on hospital admission on 15 June 2015 (day 1). Two false negative RT-PCR on upper respiratory tract samples on days 2 and 3 led to a 48-hour diagnosis delay and a decision to transfer the patient out of the negative pressure unit (NPU). Subsequent examination of sputum later on day 3 confirmed MERS coronavirus (MERS-CoV) infection. The patient was immediately moved back into the NPU and then transferred to Bamrasnaradura Infectious Disease Institute. Over 170 contacts were traced; 48 were quarantined and 122 self-monitored for symptoms. High-risk close contacts exhibiting no symptoms, and whose laboratory testing on the 12th day after exposure was negative, were released on the 14th day. The Omani Ministry of Health (MOH) was immediately notified using the International Health Regulation (IHR) mechanism. Outbreak investigation was conducted in Oman, and was both published on the World Health Organization (WHO) intranet and shared with Thailand's IHR focal point. The key to successful infection control, with no secondary transmission, were the collaborative efforts among hospitals, laboratories and MOHs of both countries.
Subject(s)
Coronavirus Infections/diagnosis , Cross Infection/virology , Infection Control , Middle East Respiratory Syndrome Coronavirus/genetics , Adult , Aged , Coronavirus Infections/transmission , Coronavirus Infections/virology , Cross Infection/diagnosis , Cross Infection/epidemiology , Cross Infection/transmission , Delayed Diagnosis , Disease Notification , Disease Outbreaks , Humans , Middle Aged , Middle East Respiratory Syndrome Coronavirus/isolation & purification , Oman/ethnology , Real-Time Polymerase Chain Reaction , Thailand/epidemiologyABSTRACT
BACKGROUND: Nipah virus (NiV) first emerged in Malaysia in 1998, with two bat species (Pteropus hypomelanus and P. vampyrus) as the putative natural reservoirs. In 2002, NiV IgG antibodies were detected in these species from Thailand, but viral RNA could not be detected for strain characterization. Two strains of NiV (Malaysia and Bangladesh) have been found in P. lylei in central Thailand, although Bangladesh strain, the causative strain for the outbreak in Bangladesh since 2001, was dominant. To understand the diversity of NiV in Thailand, this study identified NiV strain, using molecular characterizations, from P. hypomelanus in southern Thailand. FINDINGS: Pooled bat urine specimens were collected from plastic sheet underneath bat roosts in April 2010, and then monthly from December 2010 to May 2011 at an island in southern Thailand. Five in 184 specimens were positive for NiV, using duplex nested RT-PCR assay on partial nucleocapsid fragment (357 bp). Whole sequences of nucleocapsid gene from four bats were characterized. All 5 partial fragments and 4 whole nucleocapsid genes formed a monophyletic with NiV-MY. CONCLUSIONS: Our study showed that P. hypomelanus in southern Thailand and from Malaysia, a bordering country, harbored similar NiV. This finding indicates that NiV is not limited to central Thailand or P. lylei species, and it may be a source of inter-species transmission. This indicates a higher potential for a widespread NiV outbreak in Thailand. NiV surveillance in Pteropus bats, the major natural reservoirs, should be conducted continuously in countries or regions with high susceptibility to outbreaks.
Subject(s)
Chiroptera/virology , Genetic Variation , Nipah Virus/classification , Nipah Virus/isolation & purification , Animals , Nipah Virus/genetics , Nucleocapsid/genetics , Phylogeny , Polymerase Chain Reaction , RNA, Viral/genetics , Sequence Analysis, DNA , Thailand , Urine/virologyABSTRACT
Sub-passaging of QS-05, a street rabies virus (RABV) isolate, in non-neuronal cells resulted in a virus with higher pathogenicity, QS-BHK-P7. Four full-length cDNA plasmids were constructed and the corresponding recombinant viruses were recovered: rQS-05, rQS-BHK-P7 and rQS05-2475G/rQS-BHK-P7-2475A (made by switching of intergenic P-M between these two backbones). rQS-BHK-P7-2475 A virus had eight instead of seven adenosines in its poly(A) sequence. Interestingly, mutant viruses with 6 or 8 adenosines infected more neuroblastoma cells than their parental ones. Mice that were infected intracerebrally and intramuscularly with rQS05-2475G and rQS-BHK-P7 exhibited highest mortality. However, mice infected with rQS-BHK-P7-2475AA had the shortest survival time. This study demonstrates that modifications in the non-coding region may play a role in determining the virulence of RABV.
Subject(s)
RNA, Messenger/genetics , RNA, Untranslated/genetics , RNA, Viral/genetics , Rabies virus/genetics , Rabies virus/pathogenicity , Animals , Cell Line , Female , Injections, Intramuscular , Mice, Inbred ICR , Neurons/virology , Rabies/pathology , Rabies virus/isolation & purification , Survival Analysis , Time Factors , Virulence , Virus CultivationABSTRACT
Combined active and passive immunization has been established to be an optimal strategy for rabies post-exposure prophylaxis (PEP). Prompt administration of vaccine and rabies immunoglobulin (RIG) can reliably prevent the disease. However, RIG is unavailable and unaffordable in the majority of cases. On the basis of a model experiment using hamsters, we demonstrated that vaccine injection at the wound site in the same manner as administration of RIG provided protective efficacy that was not inferior to the current optimal PEP, a combination of vaccination and RIG. Further study is needed to determine whether it can replace the use of RIG.
Subject(s)
Immunoglobulins/immunology , Post-Exposure Prophylaxis , Rabies Vaccines/immunology , Rabies/prevention & control , Animals , Cricetinae , Rabies/mortality , Rabies Vaccines/administration & dosage , Rabies virus/immunologyABSTRACT
Hepatitis C virus (HCV) is among the most relevant causes of liver cirrhosis and hepatocellular carcinoma. Research is complicated by a lack of accessible small animal models. The systematic investigation of viruses of small mammals could guide efforts to establish such models, while providing insight into viral evolutionary biology. We have assembled the so-far largest collection of small-mammal samples from around the world, qualified to be screened for bloodborne viruses, including sera and organs from 4,770 rodents (41 species); and sera from 2,939 bats (51 species). Three highly divergent rodent hepacivirus clades were detected in 27 (1.8%) of 1,465 European bank voles (Myodes glareolus) and 10 (1.9%) of 518 South African four-striped mice (Rhabdomys pumilio). Bats showed anti-HCV immunoblot reactivities but no virus detection, although the genetic relatedness suggested by the serologic results should have enabled RNA detection using the broadly reactive PCR assays developed for this study. 210 horses and 858 cats and dogs were tested, yielding further horse-associated hepaciviruses but none in dogs or cats. The rodent viruses were equidistant to HCV, exceeding by far the diversity of HCV and the canine/equine hepaciviruses taken together. Five full genomes were sequenced, representing all viral lineages. Salient genome features and distance criteria supported classification of all viruses as hepaciviruses. Quantitative RT-PCR, RNA in-situ hybridisation, and histopathology suggested hepatic tropism with liver inflammation resembling hepatitis C. Recombinant serology for two distinct hepacivirus lineages in 97 bank voles identified seroprevalence rates of 8.3 and 12.4%, respectively. Antibodies in bank vole sera neither cross-reacted with HCV, nor the heterologous bank vole hepacivirus. Co-occurrence of RNA and antibodies was found in 3 of 57 PCR-positive bank vole sera (5.3%). Our data enable new hypotheses regarding HCV evolution and encourage efforts to develop rodent surrogate models for HCV.
Subject(s)
Evolution, Molecular , Genome, Viral , Hepacivirus , Hepatitis C Antibodies/blood , Hepatitis C , Hepatitis, Animal , RNA, Viral , Rodentia , Animals , Base Sequence , Cats , Dogs , Hepacivirus/genetics , Hepacivirus/metabolism , Hepatitis C/blood , Hepatitis C/genetics , Hepatitis C/virology , Hepatitis, Animal/blood , Hepatitis, Animal/genetics , Hepatitis, Animal/virology , Horses , Molecular Sequence Data , RNA, Viral/blood , RNA, Viral/genetics , Rodentia/blood , Rodentia/virologyABSTRACT
BACKGROUND: Bats are reservoirs for a diverse range of coronaviruses (CoVs), including those closely related to human pathogens such as Severe Acute Respiratory Syndrome (SARS) CoV and Middle East Respiratory Syndrome CoV. There are approximately 139 bat species reported to date in Thailand, of which two are endemic species. Due to the zoonotic potential of CoVs, standardized surveillance efforts to characterize viral diversity in wildlife are imperative. FINDINGS: A total of 626 bats from 19 different bat species were individually sampled from 5 provinces in Eastern Thailand between 2008 and 2013 (84 fecal and 542 rectal swabs). Samples collected (either fresh feces or rectal swabs) were placed directly into RNA stabilization reagent, transported on ice within 24 hours and preserved at -80°C until further analysis. CoV RNA was detected in 47 specimens (7.6%), from 13 different bat species, using broadly reactive consensus PCR primers targeting the RNA-Dependent RNA Polymerase gene designed to detect all CoVs. Thirty seven alphacoronaviruses, nine lineage D betacoronaviruses, and one lineage B betacoronavirus (SARS-CoV related) were identified. Six new bat CoV reservoirs were identified in our study, namely Cynopterus sphinx, Taphozous melanopogon, Hipposideros lekaguli, Rhinolophus shameli, Scotophilus heathii and Megaderma lyra. CONCLUSIONS: CoVs from the same genetic lineage were found in different bat species roosting in similar or different locations. These data suggest that bat CoV lineages are not strictly concordant with their hosts. Our phylogenetic data indicates high diversity and a complex ecology of CoVs in bats sampled from specific areas in eastern regions of Thailand. Further characterization of additional CoV genes may be useful to better describe the CoV divergence.
Subject(s)
Chiroptera/virology , Coronavirus Infections/veterinary , Coronavirus/genetics , Coronavirus/isolation & purification , Genetic Variation , Animals , Coronavirus/classification , Coronavirus Infections/virology , Genome, Viral , Humans , Molecular Sequence Data , Phylogeny , ThailandABSTRACT
Rabies remains a constant threat to humans throughout much of Asia. The dog is the main reservoir and vector with wildlife playing a very minor role. No Asian country or region has been declared rabies free by WHO in over two decades and there is evidence of canine rabies spread to new regions during the past 10 years. We now have the knowledge and technology to control canine rabies. The main barrier in managing this costly endemic is lack of motivation by authorities to address this issue along with regional inability of public health and livestock (agriculture) officials to tackle this issue in cooperation and coordination. Rabies is one of the first recognized zoonoses and a model for a true "One Health" management goal where human; veterinary, and government officials must work together in harmony to defeat this disease.
Subject(s)
Communicable Diseases, Emerging/prevention & control , Rabies/prevention & control , Zoonoses/prevention & control , Animals , Asia , Communicable Diseases, Emerging/transmission , Dogs , Humans , Rabies/diagnosis , Rabies/therapy , Rabies/transmission , Zoonoses/diagnosis , Zoonoses/therapy , Zoonoses/transmissionABSTRACT
Co-infection with Brucella melitensis and Coxiella burnetii has been rarely reported. To date, there are only two co-infection case reports from Croatia and China which diagnosed the infections mainly through the use of serological tests. In this report, we present the first case of molecularly confirmed B. melitensis bacteremia and C. burnetii spondylodiscitis co-infection in a goat dairy farmer who presented with lumbosacral spondylodiscitis and bilateral psoas abscesses. From the blood culture, B. melitensis was identified by using 16S rRNA gene sequencing and specific PCR. Lumbar bone tissue was found to be positive for C. burnetii using multiplex real-time PCR and was confirmed with a positive result from conventional PCR which detected the infection through the identification of the IS1111 gene. The patient's condition improved after decompressive laminectomy was performed and administration of antibiotics regimen: intravenous gentamicin, oral rifampicin, and oral doxycycline. From our case, it is important to raise awareness of this underreported co-infection with multiple zoonotic diseases, especially Q fever and brucellosis, which share the same exposure risk. Moreover, we also emphasize the use of advanced molecular techniques to improve the diagnostic efficiency and reduce the use of time-consuming procedures among patients who are continuously exposed to such risk factors in areas with high seroprevalence of these zoonotic diseases.
ABSTRACT
Novel SARS-CoV-2 variants have multiple mutations that may impact molecular diagnostics. The markedly conserved S2 subunit may be utilized to detect new variants. A comparison of 694 specimens (2019-2022) in Thailand using a commercial RT-PCR kit and the kit in combination with S2 primers and a probe was performed. Delayed amplification in ORF1ab was detected in one BA.4 omicron, whereas no amplification problem was encountered in the S2 target. There were no statistically significant differences in mean Ct value between the target genes (E, N, ORF1ab, and S2) and no significant differences in mean Ct value between the reagents. Furthermore, 230,821 nucleotide sequences submitted by 20 representative counties in each region (Jan-Oct 2022) have been checked for mutations in S2 primers and probe using PrimerChecker; there is a very low chance of encountering performance problems. The S2 primers and probe are still bound to the top five currently circulating variants in all countries and Thailand without mismatch recognition (Jun-Nov 2023). This study shows the possible benefits of detecting S2 in combination with simultaneously detecting three genes in a kit without affecting the Ct value of each target. The S2 subunit may be a promising target for the detection of SARS-CoV-2 variants with multiple mutations.
ABSTRACT
BACKGROUND: Data on encephalitis in Thailand have not been completely described. Etiologies remain largely unknown. We prospectively analyzed 103 Thai patients from 27 provinces for the causes of encephalitis using clinical, microbiological and neuroimaging indices; caseswithout a diagnosis were evaluated for autoimmune causes of encephalitis. METHODS: Patients with encephalitis and/or myelitis were prospectively studied between October 2010 and August 2012. Cases associated with bacterial, rickettsial and mycobacterial diseases were excluded. Herpes viruses 1-6 and enteroviruses infection was diagnosed using PCR evaluation of CSF; dengue and JE viruses infection, by serology. The serum of test-negative patients was evaluated for the presence of autoantibodies. RESULTS: 103 patients were recruited. Fifty-three patients (52%) had no etiologies identified. Twenty-five patients (24%) were associated with infections. Immune encephalitis was found in 25 (24%); neuropsychiatric lupus erythematosus (4), demyelinating diseases (3), Behcet's disease (1) and the remaining had antibodies to NMDAR (5), ANNA-2 (6), Yo (2), AMPA (1), GABA (1), VGKC (1) and NMDA coexisting with ANNA-2 (1). Presenting symptoms in the autoimmune group included behavioral changes in 6/25 (versus 12/25 in infectious and 13/53 in unknown group) and as psychosis in 6/25 (versus 0/25 infectious and 2/53 unknown). Seizures were found in 6/25 autoimmune, 4/25 infectious and 19/53 unknown group. Two patients with anti-ANNA-2 and one anti-Yo had temporal lobe involvement by magnetic resonance imaging. Two immune encephalitis patients with antibodies to NMDAR and ANNA-2 had ovarian tumors. CONCLUSIONS: Autoantibody-associated encephalitis should be considered in the differential diagnosis and management algorithm regardless of clinical and neuroimaging features.