Asymptomatic Infections: Infections that do not exhibit symptoms.Leishmania infantum: A parasitic hemoflagellate of the subgenus Leishmania leishmania that infects man and animals and causes visceral leishmaniasis (LEISHMANIASIS, VISCERAL). Human infections are confined almost entirely to children. This parasite is commonly seen in dogs, other Canidae, and porcupines with humans considered only an accidental host. Transmission is by Phlebotomus sandflies.Leishmaniasis, Visceral: A chronic disease caused by LEISHMANIA DONOVANI and transmitted by the bite of several sandflies of the genera Phlebotomus and Lutzomyia. It is commonly characterized by fever, chills, vomiting, anemia, hepatosplenomegaly, leukopenia, hypergammaglobulinemia, emaciation, and an earth-gray color of the skin. The disease is classified into three main types according to geographic distribution: Indian, Mediterranean (or infantile), and African.Antibodies, Protozoan: Immunoglobulins produced in a response to PROTOZOAN ANTIGENS.Carrier State: The condition of harboring an infective organism without manifesting symptoms of infection. The organism must be readily transmissible to another susceptible host.Antigens, Protozoan: Any part or derivative of any protozoan that elicits immunity; malaria (Plasmodium) and trypanosome antigens are presently the most frequently encountered.Asymptomatic Diseases: Diseases that do not exhibit symptoms.Malaria, Falciparum: Malaria caused by PLASMODIUM FALCIPARUM. This is the severest form of malaria and is associated with the highest levels of parasites in the blood. This disease is characterized by irregularly recurring febrile paroxysms that in extreme cases occur with acute cerebral, renal, or gastrointestinal manifestations.Parasitemia: The presence of parasites (especially malarial parasites) in the blood. (Dorland, 27th ed)Plasmodium falciparum: A species of protozoa that is the causal agent of falciparum malaria (MALARIA, FALCIPARUM). It is most prevalent in the tropics and subtropics.Endemic Diseases: The constant presence of diseases or infectious agents within a given geographic area or population group. It may also refer to the usual prevalence of a given disease with such area or group. It includes holoendemic and hyperendemic diseases. A holoendemic disease is one for which a high prevalent level of infection begins early in life and affects most of the child population, leading to a state of equilibrium such that the adult population shows evidence of the disease much less commonly than do children (malaria in many communities is a holoendemic disease). A hyperendemic disease is one that is constantly present at a high incidence and/or prevalence rate and affects all groups equally. (Last, A Dictionary of Epidemiology, 3d ed, p53, 78, 80)Rotavirus Infections: Infection with any of the rotaviruses. Specific infections include human infantile diarrhea, neonatal calf diarrhea, and epidemic diarrhea of infant mice.BrazilDisease Outbreaks: Sudden increase in the incidence of a disease. The concept includes EPIDEMICS and PANDEMICS.Protozoan Proteins: Proteins found in any species of protozoan.Seroepidemiologic Studies: EPIDEMIOLOGIC STUDIES based on the detection through serological testing of characteristic change in the serum level of specific ANTIBODIES. Latent subclinical infections and carrier states can thus be detected in addition to clinically overt cases.Leishmania: A genus of flagellate protozoa comprising several species that are pathogenic for humans. Organisms of this genus have an amastigote and a promastigote stage in their life cycles. As a result of enzymatic studies this single genus has been divided into two subgenera: Leishmania leishmania and Leishmania viannia. Species within the Leishmania leishmania subgenus include: L. aethiopica, L. arabica, L. donovani, L. enrietti, L. gerbilli, L. hertigi, L. infantum, L. major, L. mexicana, and L. tropica. The following species are those that compose the Leishmania viannia subgenus: L. braziliensis, L. guyanensis, L. lainsoni, L. naiffi, and L. shawi.Feces: Excrement from the INTESTINES, containing unabsorbed solids, waste products, secretions, and BACTERIA of the DIGESTIVE SYSTEM.Serologic Tests: Diagnostic procedures involving immunoglobulin reactions.Gonorrhea: Acute infectious disease characterized by primary invasion of the urogenital tract. The etiologic agent, NEISSERIA GONORRHOEAE, was isolated by Neisser in 1879.Malaria, Vivax: Malaria caused by PLASMODIUM VIVAX. This form of malaria is less severe than MALARIA, FALCIPARUM, but there is a higher probability for relapses to occur. Febrile paroxysms often occur every other day.Antibodies, Viral: Immunoglobulins produced in response to VIRAL ANTIGENS.Enzyme-Linked Immunosorbent Assay: An immunoassay utilizing an antibody labeled with an enzyme marker such as horseradish peroxidase. While either the enzyme or the antibody is bound to an immunosorbent substrate, they both retain their biologic activity; the change in enzyme activity as a result of the enzyme-antibody-antigen reaction is proportional to the concentration of the antigen and can be measured spectrophotometrically or with the naked eye. Many variations of the method have been developed.Rotavirus: A genus of REOVIRIDAE, causing acute gastroenteritis in BIRDS and MAMMALS, including humans. Transmission is horizontal and by environmental contamination. Seven species (Rotaviruses A thru G) are recognized.Microscopy: The use of instrumentation and techniques for visualizing material and details that cannot be seen by the unaided eye. It is usually done by enlarging images, transmitted by light or electron beams, with optical or magnetic lenses that magnify the entire image field. With scanning microscopy, images are generated by collecting output from the specimen in a point-by-point fashion, on a magnified scale, as it is scanned by a narrow beam of light or electrons, a laser, a conductive probe, or a topographical probe.DNA, Protozoan: Deoxyribonucleic acid that makes up the genetic material of protozoa.Plasmodium: A genus of protozoa that comprise the malaria parasites of mammals. Four species infect humans (although occasional infections with primate malarias may occur). These are PLASMODIUM FALCIPARUM; PLASMODIUM MALARIAE; PLASMODIUM OVALE, and PLASMODIUM VIVAX. Species causing infection in vertebrates other than man include: PLASMODIUM BERGHEI; PLASMODIUM CHABAUDI; P. vinckei, and PLASMODIUM YOELII in rodents; P. brasilianum, PLASMODIUM CYNOMOLGI; and PLASMODIUM KNOWLESI in monkeys; and PLASMODIUM GALLINACEUM in chickens.Chlamydia Infections: Infections with bacteria of the genus CHLAMYDIA.Malaria: A protozoan disease caused in humans by four species of the PLASMODIUM genus: PLASMODIUM FALCIPARUM; PLASMODIUM VIVAX; PLASMODIUM OVALE; and PLASMODIUM MALARIAE; and transmitted by the bite of an infected female mosquito of the genus ANOPHELES. Malaria is endemic in parts of Asia, Africa, Central and South America, Oceania, and certain Caribbean islands. It is characterized by extreme exhaustion associated with paroxysms of high FEVER; SWEATING; shaking CHILLS; and ANEMIA. Malaria in ANIMALS is caused by other species of plasmodia.Diarrhea: An increased liquidity or decreased consistency of FECES, such as running stool. Fecal consistency is related to the ratio of water-holding capacity of insoluble solids to total water, rather than the amount of water present. Diarrhea is not hyperdefecation or increased fecal weight.Plasmodium vivax: A protozoan parasite that causes vivax malaria (MALARIA, VIVAX). This species is found almost everywhere malaria is endemic and is the only one that has a range extending into the temperate regions.Polymerase Chain Reaction: In vitro method for producing large amounts of specific DNA or RNA fragments of defined length and sequence from small amounts of short oligonucleotide flanking sequences (primers). The essential steps include thermal denaturation of the double-stranded target molecules, annealing of the primers to their complementary sequences, and extension of the annealed primers by enzymatic synthesis with DNA polymerase. The reaction is efficient, specific, and extremely sensitive. Uses for the reaction include disease diagnosis, detection of difficult-to-isolate pathogens, mutation analysis, genetic testing, DNA sequencing, and analyzing evolutionary relationships.Prevalence: The total number of cases of a given disease in a specified population at a designated time. It is differentiated from INCIDENCE, which refers to the number of new cases in the population at a given time.Influenza, Human: An acute viral infection in humans involving the respiratory tract. It is marked by inflammation of the NASAL MUCOSA; the PHARYNX; and conjunctiva, and by headache and severe, often generalized, myalgia.Infant, Newborn: An infant during the first month after birth.Antibodies, Bacterial: Immunoglobulins produced in a response to BACTERIAL ANTIGENS.Chlamydia trachomatis: Type species of CHLAMYDIA causing a variety of ocular and urogenital diseases.IndiaAntimalarials: Agents used in the treatment of malaria. They are usually classified on the basis of their action against plasmodia at different stages in their life cycle in the human. (From AMA, Drug Evaluations Annual, 1992, p1585)RNA, Viral: Ribonucleic acid that makes up the genetic material of viruses.Immunoglobulin G: The major immunoglobulin isotype class in normal human serum. There are several isotype subclasses of IgG, for example, IgG1, IgG2A, and IgG2B.Seasons: Divisions of the year according to some regularly recurrent phenomena usually astronomical or climatic. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)Viral Load: The quantity of measurable virus in a body fluid. Change in viral load, measured in plasma, is sometimes used as a SURROGATE MARKER in disease progression.Genotype: The genetic constitution of the individual, comprising the ALLELES present at each GENETIC LOCUS.DNA, Viral: Deoxyribonucleic acid that makes up the genetic material of viruses.Sequence Analysis, DNA: A multistage process that includes cloning, physical mapping, subcloning, determination of the DNA SEQUENCE, and information analysis.Molecular Sequence Data: Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.Cohort Studies: Studies in which subsets of a defined population are identified. These groups may or may not be exposed to factors hypothesized to influence the probability of the occurrence of a particular disease or other outcome. Cohorts are defined populations which, as a whole, are followed in an attempt to determine distinguishing subgroup characteristics.Cross-Sectional Studies: Studies in which the presence or absence of disease or other health-related variables are determined in each member of the study population or in a representative sample at one particular time. This contrasts with LONGITUDINAL STUDIES which are followed over a period of time.Phylogeny: The relationships of groups of organisms as reflected by their genetic makeup.Incidence: The number of new cases of a given disease during a given period in a specified population. It also is used for the rate at which new events occur in a defined population. It is differentiated from PREVALENCE, which refers to all cases, new or old, in the population at a given time.Age Factors: Age as a constituent element or influence contributing to the production of a result. It may be applicable to the cause or the effect of a circumstance. It is used with human or animal concepts but should be differentiated from AGING, a physiological process, and TIME FACTORS which refers only to the passage of time.Prospective Studies: Observation of a population for a sufficient number of persons over a sufficient number of years to generate incidence or mortality rates subsequent to the selection of the study group.Sensitivity and Specificity: Binary classification measures to assess test results. Sensitivity or recall rate is the proportion of true positives. Specificity is the probability of correctly determining the absence of a condition. (From Last, Dictionary of Epidemiology, 2d ed)Base Sequence: The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.Risk Factors: An aspect of personal behavior or lifestyle, environmental exposure, or inborn or inherited characteristic, which, on the basis of epidemiologic evidence, is known to be associated with a health-related condition considered important to prevent.Time Factors: Elements of limited time intervals, contributing to particular results or situations.

Household transmission of the 2009 pandemic A/H1N1 influenza virus: elevated laboratory-confirmed secondary attack rates and evidence of asymptomatic infections. (1/107)

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Rotavirus antigenemia in Indian children with rotavirus gastroenteritis and asymptomatic infections. (2/107)

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Increased frequency of anti-retina antibodies in asymptomatic patients with chronic t. gondii infection. (3/107)

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Unapparent microsporidial infection among immunocompetent humans in the Czech Republic. (4/107)

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IL-17 and Regulatory Cytokines (IL-10 and IL-27) in L. braziliensis Infection. (5/107)

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Antileishmania immunological tests for asymptomatic subjects living in a visceral leishmaniasis-endemic area in Brazil. (6/107)

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Pharmacokinetics and pharmacodynamics of artesunate and dihydroartemisinin following oral treatment in pregnant women with asymptomatic Plasmodium falciparum infections in Kinshasa DRC. (7/107)

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Clearance of asymptomatic P. falciparum Infections Interacts with the number of clones to predict the risk of subsequent malaria in Kenyan children. (8/107)

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  • This study was detecting the prevalence of asymptomatic bacteriuria (ABU) caused by Proteus mirabilis in RA patients to shed light on its rule in RA pathogenesis.Methods: This work has been conducted in medical Microbiology and Immunology Department and Rheumatology and Rehabitilation Department, Faculty of Medicine, Zagazig University, during the period from May 2017 to May 2018 over a period of 12 months. (who.int)
  • Malaria remains among the world's deadliest diseases, and control efforts depend critically on the availability of effective diagnostic tools, particularly for the identification of asymptomatic infections, which play a key role in disease persistence and may account for most instances of transmission but often evade detection by current screening methods. (pnas.org)
  • During a period of one year, we screened 497 afebrile males to investigate the prevalence of asymptomatic P. falciparum parasitemia in villages near Lambaréné, Gabon by use of three different methods. (ajtmh.org)
  • Data like this highlights the importance of testing asymptomatic people, said Medical Director of the Vancouver Infectious Diseases Centre Dr. Brian Conway, on CTV's News Channel Saturday. (ctvnews.ca)
  • BEIJING (Reuters) - China, where the coronavirus outbreak first emerged in December, reported dwindling new infections on Wednesday and for the first time disclosed the number of asymptomatic cases, which could complicate how trends in the outbreak are read. (reuters.com)
  • Asymptomatic infections would not cause a major outbreak if the transmission chain was cut, the Chinese government's senior medical adviser, Zhong Nanshan, told state-run Shenzhen TV. (reuters.com)
  • Review of hospital B's microbiology records revealed no episodes of postoperative GAS infection during the 6 months before the outbreak. (cdc.gov)
  • Evidence suggests that many Ebola infections are asymptomatic, a factor overlooked by recent outbreak summaries and projections. (abovetopsecret.com)
  • In a residential care facility this can be particularly problematic as it increases the risk of an outbreak of antibiotic-resistant infections. (bpac.org.nz)
  • One of the major challenges in controlling the coronavirus disease 2019 (COVID-19) outbreak is its asymptomatic transmission. (cdc.gov)
  • From all participants who coronavirus 2 (SARS-CoV-2) leads to an antibody provided informed consent, we collected serum sam- response, even in those who are completely asymp- ples at 8 months after infection. (cdc.gov)
  • The analysis included specimens that were received for testing at the CDC Arboviral Diseases Branch and confirmed Zika virus infection was defined as detection of Zika virus RNA by reverse transcription-polymerase chain reaction, or anti-Zika immunoglobulin M antibodies by enzyme-linked immunosorbent assay with neutralizing antibody titers against Zika virus, at levels greater than or equal to fourfold higher than those against dengue virus. (mdedge.com)
  • We therefore studied young Gambian children at an age at which many acquire EBV, monitoring them over six months for evidence of EBV infection by virus load in the blood, virus-specific IgM and IgG antibody status, and virus-specific CD8+ T-cell responses. (prolekare.cz)
  • One of the next steps of this study could be to determine the antibody threshold needed to protect against symptomatic ZIKV infection. (immunopaedia.org.za)
  • The mean ELISA optical density decreased sig- clined from 219.4 at 2 months to 143.7 at 5 months after nificantly from 2 to 5 months after infection (4.93 at 2 infection, indicating a waning antibody response. (cdc.gov)
  • It is reassuring that the proportion of asymptomatic pregnant women with confirmed Zika virus infection in this report was low" and not unexpected in the current U.S. setting, where most exposure to the Zika virus is travel-associated, the investigators wrote. (mdedge.com)
  • Our results also showed that a large number of asymptomatic food handlers were infected with norovirus GII/4 strains. (asm.org)
  • To get as close as possibly in an animal model, the researchers developed two Salmonella enterica Typhimurium (S. Typhimurium) strains, which cause systemic typhoid fever-like infection in immunocompetent mice. (ki.se)
  • The researchers infected mice orally with the two bacterial strains and found that mice infected with the strain carrying the intact typhoid toxin had higher survival rates within the first 10 days post infection. (ki.se)
  • Most strains resolve within 6 months of infection, but some persist and can cause cervical dysplasia. (medindia.net)
  • We tested in total 192 samples collected from 48 asymptomatic schoolchildren (C1 to C48) who were followed during two consecutive years (2010 and 2011), and sampled twice each year (May and November) corresponding to the dry and rainy seasons, respectively. (springer.com)
  • When reporting the results of cervical Pap smears tests usually a remark is made on the possible presence of infection based on cytological criteria [ 5 ]. (hindawi.com)
  • Our results establish a temporal pattern of host molecular responses that differentiates symptomatic from asymptomatic infections and reveals an asymptomatic host-unique non-passive response signature, suggesting novel putative molecular targets for both prognostic assessment and ameliorative therapeutic intervention in seasonal and pandemic influenza. (plos.org)
  • These results suggest that the increasing knowledge about the importance of HPV infection is probably leading to new prevention strategies for this disease. (springer.com)
  • This led researchers to study whether primary, preconceptual ZIKV infection results in protection from subsequent infection. (immunopaedia.org.za)