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Heliyon Oct 2021Norovirus infection is a major cause of acute gastroenteritis, although some infected individuals are asymptomatic. GII.4 is the predominant genotype worldwide and,...
Norovirus infection is a major cause of acute gastroenteritis, although some infected individuals are asymptomatic. GII.4 is the predominant genotype worldwide and, since 2000, has been the most prevalent in patients in Thailand with acute gastroenteritis. We screened stool samples for norovirus in 786 patients with acute gastroenteritis who were admitted to a hospital in Bangkok from 2017 to early 2019 and detected it in 136 specimens (17.3%). Eight and 124 specimens were positive for the GI and GII genogroups, respectively, and the remaining 4 specimens were double-positive. Nine genotypes (GI.3, GI.5, GII.2, GII.3, GII.4, GII.6, GII.8, GII.13, and GII.17) were identified from 140 strains, and 72 strains (51.4%) were GII.4. We had previously conducted a one-year survey of norovirus infection in residents of a community in Bangkok from May 2018 to April 2019 and found that a substantial portion of the residents were infected asymptomatically. The 9 genotypes identified in the patients were also commonly identified in the community residents. To investigate the relationship between noroviruses identified in the acute gastroenteritis patients and those identified in the community residents, phylogenetic tree analysis was conducted. Of the 9 genotypes, 8 showed similarities in both their genomic sequences and their deduced amino acid sequences. In addition, strain replacement of GI.3 was observed in both the patients and the community residents within the overlapping period. These results suggested that norovirus spreads efficiently to the community by simultaneously causing symptomatic and asymptomatic infections.
PubMed: 34761137
DOI: 10.1016/j.heliyon.2021.e08250 -
Medicinski Pregled 2016Tick-borne meningoencephalitis virus is a flavivirus that causes the most important vector-borne central nervous system infection in many countries of Europe and Asia.... (Review)
Review
INTRODUCTION
Tick-borne meningoencephalitis virus is a flavivirus that causes the most important vector-borne central nervous system infection in many countries of Europe and Asia. There are three subtypes of tick-borne encephalitis virus: European, Siberian and the Far-Eastern subtype.
TRANSMISSION
In endemic areas, the virus remains in transmissive cycles between Ixodes ticks and small rodents.
CLINICAL PICTURE
In most cases (70-98%) infection goes asymptomatically. In about one-third of meningitis cases, meningoencephalitis or meningomyelitis is developed. Postencephalytic syndrome may be the complication of the infection, presenting with neurological symptoms.
DIAGNOSIS
Etiologic diagnosis of tick-borne meningoencephalitis is only made on basis of laboratory analyses. Reverse transcription-polymerase chain reaction is used for determining the presence of virus in the blood and cerebrospinal fluid. Antibodies in blood and cerebrospinal fluid can be detected by serological tests.
PREVENTION
The most efficient way to control this potentially severe disease with possible serious long-term consequences is vaccination. It should be recommended to persons who live or travel to endemic areas.
CONCLUSION
In Serbia, tick-borne encephalitis virus infection belongs to the list of reportable diseases; however, there are no reported cases because the diagnostics is not performed routinely. We believe that the significance of this zoonosis must be examined in our country and some of its parts because of preliminary positive serological findings found out in Vojvodina as well as because of reported cases in neighboring countries such as Hungary and Croatia and its worldwide distribution.
Topics: Animals; Antibodies, Viral; Asia; Asymptomatic Infections; Encephalitis Viruses, Tick-Borne; Encephalitis, Tick-Borne; Endemic Diseases; Europe; Humans; Insect Vectors; Ixodes; Reverse Transcriptase Polymerase Chain Reaction; Viral Vaccines
PubMed: 27506096
DOI: 10.2298/mpns1604093h -
Best Practice & Research. Clinical... Dec 2011Primary biliary cirrhosis is the archetypal autoimmune liver disease, with the disease label describing a chronic granulomatous lymphocytic small bile duct cholangitis,... (Review)
Review
Primary biliary cirrhosis is the archetypal autoimmune liver disease, with the disease label describing a chronic granulomatous lymphocytic small bile duct cholangitis, which now most commonly presents asymptomatically and at an early pre-cirrhotic stage. Disease is more common than thought, with 1 in 1000 women over the age of 40 affected. Characteristic immunologic features of the disease assist clinicians in ready non-invasive diagnosis of patients, even if asymptomatic with only anicteric/cholestatic liver biochemical profiles. Over 90% of patients are anti-mitochondrial antibody positive, and for those negative, a significant proportion have highly specific anti-nuclear antibody profiles. Liver biopsy remains useful in certain settings where clarity is needed to confirm diagnosis, exclude alternative disease, and assess the relative contribution of PBC to other co-existent liver injury, and seeks to demonstrate in particular the classic bile duct lesions, as well as the degree of interface activity.
Topics: Alkaline Phosphatase; Antibodies, Antinuclear; Autoimmune Diseases; Biopsy; Humans; Liver Cirrhosis, Biliary; Mitochondria; gamma-Glutamyltransferase
PubMed: 22117636
DOI: 10.1016/j.bpg.2011.10.005 -
Mathematical Methods in the Applied... Jan 2022Coronavirus pandemic (COVID-19) hit the world in December 2019, and only less than 5% of the 15 million cases were recorded in Africa. A major call for concern was the...
Coronavirus pandemic (COVID-19) hit the world in December 2019, and only less than 5% of the 15 million cases were recorded in Africa. A major call for concern was the significant rise from 2% in May 2020 to 4.67% by the end of July 15, 2020. This drastic increase calls for quick intervention in the transmission and control strategy of COVID-19 in Africa. A mathematical model to theoretically investigate the consequence of ignoring asymptomatic cases on COVID-19 spread in Africa is proposed in this study. A qualitative analysis of the model is carried out with and without re-infection, and the reproduction number is obtained under re-infection. The results indicate that increasing case detection to detect asymptomatically infected individuals will be very effective in containing and reducing the burden of COVID-19 in Africa. In addition, the fact that it has not been confirmed whether a recovered individual can be re-infected or not, then enforcing a living condition where recovered individuals are not allowed to mix with the susceptible or exposed individuals will help in containing the spread of COVID-19.
PubMed: 34908633
DOI: 10.1002/mma.7769 -
Frontiers in Cellular and Infection... 2020As morbidity and mortality due to malaria continue to decline, the identification of individuals with a high likelihood of transmitting malaria is needed to further...
As morbidity and mortality due to malaria continue to decline, the identification of individuals with a high likelihood of transmitting malaria is needed to further reduce the prevalence of malaria. In areas of holoendemic malaria transmission, asymptomatically infected adults may be infected with transmissible gametocytes. The impact of HIV-1 on gametocyte carriage is unknown, but co-infection may lead to an increase in gametocytemia. In this study, a panel of qPCR assays was used to quantify gametocyte stage-specific transcripts present in dried blood spots obtained from asymptomatic adults seeking voluntary HIV testing in Kombewa, Kenya. A total of 1,116 -specific -positive samples were tested and 20.5% of these individuals had detectable gametocyte-specific transcripts. Individuals also infected with HIV-1 were 1.82 times more likely to be gametocyte positive (P<0.0001) and had significantly higher gametocyte copy numbers when compared to HIV-negative individuals. Additionally, HIV-1 positivity was associated with higher gametocyte prevalence in men and increased gametocyte carriage with age. Overall, these data suggest that HIV-positive individuals may have an increased risk of transmitting malaria parasites in regions with endemic malaria transmission and therefore should be at a higher priority for treatment with gametocidal antimalarial drugs.
Topics: Adult; HIV Infections; HIV-1; Humans; Kenya; Malaria, Falciparum; Male; Plasmodium falciparum; Prevalence
PubMed: 33614525
DOI: 10.3389/fcimb.2020.600106 -
Clinical Infectious Diseases : An... Apr 2024Neglected tropical diseases are responsible for considerable morbidity and mortality in low-income populations. International efforts have reduced their global burden,...
BACKGROUND
Neglected tropical diseases are responsible for considerable morbidity and mortality in low-income populations. International efforts have reduced their global burden, but transmission is persistent and case-finding-based interventions rarely target asymptomatic individuals.
METHODS
We develop a generic mathematical modeling framework for analyzing the dynamics of visceral leishmaniasis in the Indian sub-continent (VL), gambiense sleeping sickness (gHAT), and Chagas disease and use it to assess the possible contribution of asymptomatics who later develop disease (pre-symptomatics) and those who do not (non-symptomatics) to the maintenance of infection. Plausible interventions, including active screening, vector control, and reduced time to detection, are simulated for the three diseases.
RESULTS
We found that the high asymptomatic contribution to transmission for Chagas and gHAT and the apparently high basic reproductive number of VL may undermine long-term control. However, the ability to treat some asymptomatics for Chagas and gHAT should make them more controllable, albeit over relatively long time periods due to the slow dynamics of these diseases. For VL, the toxicity of available therapeutics means the asymptomatic population cannot currently be treated, but combining treatment of symptomatics and vector control could yield a quick reduction in transmission.
CONCLUSIONS
Despite the uncertainty in natural history, it appears there is already a relatively good toolbox of interventions to eliminate gHAT, and it is likely that Chagas will need improvements to diagnostics and their use to better target pre-symptomatics. The situation for VL is less clear, and model predictions could be improved by additional empirical data. However, interventions may have to improve to successfully eliminate this disease.
Topics: Humans; Neglected Diseases; Chagas Disease; Asymptomatic Infections; Leishmaniasis, Visceral; Models, Theoretical; Trypanosomiasis, African; India; Animals
PubMed: 38662705
DOI: 10.1093/cid/ciae096 -
Child's Nervous System : ChNS :... Jan 2018Zika Virus (ZIKV), member of Flaviviridae family and Flavivirus genus, has recently emerged as international public health emergency after its association with neonatal... (Review)
Review
BACKGROUND
Zika Virus (ZIKV), member of Flaviviridae family and Flavivirus genus, has recently emerged as international public health emergency after its association with neonatal microcephaly cases. Clinical diagnosis hindrance involves symptom similarities produced by other arbovirus infections, therefore laboratory confirmation is of paramount importance.
DISCUSSION
The most reliable test available is based on ZIKV RNA detection from body fluid samples. However, short viremia window periods and asymptomatic infections diminish the success rate for RT-PCR positivity. Beyond molecular detection, all serology tests in areas where other Flavivirus circulates proved to be a difficult task due to the broad range of cross-reactivity, especially with dengue pre-exposed individuals.
CONCLUSION
Altogether, lack of serological diagnostic tools brings limitations to any retrospective evaluation. Those studies are central in the context of congenital infection that could occur asymptomatically and mask prevalence and risk rates.
Topics: Adult; Antibodies, Viral; Body Fluids; Humans; Infant; Infant, Newborn; Microcephaly; Pathology, Molecular; Zika Virus Infection
PubMed: 29110196
DOI: 10.1007/s00381-017-3641-5 -
Journal of the Chinese Medical... Jul 2008Eosinophilic esophagitis is a growing problem in adults in Western countries. It is characterized by nausea, vomiting, dysphagia, food impaction, epigastralgia, heart...
Eosinophilic esophagitis is a growing problem in adults in Western countries. It is characterized by nausea, vomiting, dysphagia, food impaction, epigastralgia, heart burn and chest pain. Histologic survey is the most potent diagnostic tool. The diagnostic hallmark is the presence of more than 20 eosinophils per high-powered field on esophageal specimen and the absence of mucosal eosinophilia in the stomach. We herein report an asymptomatic Chinese male with eosinophilic esophagitis, which to the best of our knowledge is the first reported case in Asia. The unusual feature of the current case was the lack of symptoms. This case confirms that a dense infiltration of esophageal eosinophils can occur asymptomatically.
Topics: Adult; Eosinophilia; Esophagitis; Humans; Male
PubMed: 18653400
DOI: 10.1016/S1726-4901(08)70140-0 -
The American Journal of Gastroenterology Dec 1994Osteopenia is a well-known complication of overt celiac disease, but whether such defective bone mineralization is present among asymptomatic or silent patients is not... (Comparative Study)
Comparative Study
OBJECTIVES
Osteopenia is a well-known complication of overt celiac disease, but whether such defective bone mineralization is present among asymptomatic or silent patients is not known. Our objectives were: 1) to examine bone mineralization of a group of asymptomatic celiac patients; 2) to compare these results with those of symptomatic patients.
METHODS
Bone mineral density of the spine and total skeleton by dual energy x-ray absorptiometry and serum parameters of mineral metabolism of eight recently diagnosed asymptomatic patients with celiac disease were studied. Results were compared with those obtained in 20 untreated symptomatic celiacs, 14 patients treated with gluten-free diet for a mean time of 15 yr, and 153 healthy adult subjects, matched by sex and age.
RESULTS
Four and five out of eight asymptomatic patients presented with reduced mineralization of the spine and the total skeleton, respectively (> 1 SD below normal values for sex and age). Two patients presented with severe osteopenia of the spine, and the other three presented with severe osteopenia of the whole skeleton (> 2 SD below mean normal values). Osteopenia at plane bone level (total skeleton) was significantly lower when compared to healthy controls (p < 0.02). Symptomatic untreated patients had significantly more severe deterioration of bone mineralization than did asymptomatics (p < 0.05) and treated patients (p < 0.05). No difference in bone mineral density was observed between treated patients and asymptomatic celiacs. Serum levels of calcium, alkaline phosphatase, 25-OH vitamin D, and parathormone did not show conclusive abnormalities.
CONCLUSIONS
Our findings provide direct evidence that reduced bone mineralization occurs in asymptomatic celiac patients before any other symptom becomes evident. Only early diagnosis and treatment of celiac disease can avoid the deterioration of the bone structure observed in all clinical status of celiac disease.
Topics: Absorptiometry, Photon; Adult; Aged; Alkaline Phosphatase; Bone Density; Bone Diseases, Metabolic; Calcifediol; Calcium; Celiac Disease; Female; Humans; Male; Middle Aged; Parathyroid Hormone
PubMed: 7977227
DOI: No ID Found -
Journal of Medical Virology Nov 2017In 2014, an outbreak of dengue virus (DENV) infection led to 45 171 clinical cases diagnosed in Guangdong province, Southern China. However, the potential risk of...
In 2014, an outbreak of dengue virus (DENV) infection led to 45 171 clinical cases diagnosed in Guangdong province, Southern China. However, the potential risk of blood donors asymptomatically infected with DENV has not been evaluated . In the current study we detected anti-DENV IgG antibody and RNA in volunteer Chinese blood donors. We found that anti-DENV IgG antibody was positively detected in 3.4% (51/1500) and two donors were detected as being DENV RNA positive out of 3000 blood samples. We concluded that the presence of potential DENV in blood donors might be potential risk for blood safety. Therefore, screening for DENV infection should be considered in blood donations during a period of dengue outbreak in high epidemic area of China.
Topics: Adult; Antibodies, Viral; Asymptomatic Infections; Blood Donors; China; Dengue; Dengue Virus; Disease Outbreaks; Female; Genotype; Humans; Immunoglobulin G; Male; Phylogeny; RNA, Viral; Risk Factors; Sequence Analysis, DNA; Young Adult
PubMed: 28639699
DOI: 10.1002/jmv.24883