• Parasites, Hosts and Diseases
• /
• v.54 no.6
• /
• pp.797-801
• /
• 2016

Heishui county, located in northwest Sichuan province, southwestern China, is an endemic area of zoonotic visceral leishmaniasis (VL) and is the most intractable area. VL is never destroyed in it. Asymptomatic dogs (Leishmania parasites have been diagnosed but clinically healthy) are considered to be a potential reservoir host in zoonotic VL area, and most can lead to infection of individuals, that is a new challenge for controlling VL in humans. The present study aimed to assess the Leishmania infection rate of asymptomatic dogs in Heishui county. Total 105 asymptomatic domestic dogs were gathered from 4 districts in Heishui county to investigate the infection rate with serological and molecular methods based on ELISA and kinetoplast minicircle DNA(kDNA) PCR, respectively. Out of 105 dogs, 44 (41.9%) were positive by more than 1 method; 21 (20.0%) were positive by ELISA, and 30 (28.6%) were positive by kDNA-PCR. Our study showed that Leishmania infection of domestic dogs which is clinically healthy is prevalent in the studied district, and the asymptomatic dogs infected by Leishmania may be the primary reason for the prevalence of visceral leishmaniasis in the area.

• Journal of Fisheries and Marine Sciences Education
• /
• v.27 no.4
• /
• pp.1184-1193
• /
• 2015

Monitoring for megalocytivirus infection was conducted for ten months from March to December in 2013 in 15 aquatic farms culturing, red sea bream, rock bream, rock fish and black sea bream around Tongyoung coastal area in Korea, to assess spatial and temporal variability of detection prevalence, and to explore possible links with seawater temperature. In nested-PCR targeted major capsid protein (MCP) gene, asymptomatic megalocytivirus infection was detected in the externally healthy farmed fish with a significant prevalence in range from 0 to 58.3% for ten months. Higher prevalence of megalocytivirus (46.7% - 57.1%) was observed in high water temperature season from September to November than that in other months with lower prevalence of 0.0% to 20.0%. Even though an acute infection of megalocytivirus was occurred in rock bream (positive in the first PCR) with high mortality in one of fifteen farms, there was no expansion or transmission of the disease to the rock fish and red sea bream culturing in net cage just proximal to the rock bream cage in which disease outbreaked. Nucleotide sequence analysis of the cloned MCP gene isolated asymptomatically infected rock fish revealed that the megalocytivirus in this study was clustered together with the rock bream iridovirus (RBIV) under the subgroup II of the genus megalocytivirus (Iridoviridae), which is known to be the major megalocytivirus strain in Korea. The typical histopathological signs were not found in the spleen of rock fish asymptomatically infected by megalocytivirus. Experimental infection of rock bream with the spleen homogenate of the rock fish infected asymptomatically did not induce any mortality unlike the homogenate of infected rock bream with hih mortlity. However, these results may suggest that the asymptomatic infection of megalocytivirus in other fish species can be a potential risk threatening aquaculture industries as a transmission factor of megalocytivirus to susceptible fish species, especially rock bream.

• Journal of Food Hygiene and Safety
• /
• v.32 no.6
• /
• pp.455-459
• /
• 2017

Norovirus (NoV) is the most common cause of acute gastroenteritis in all age groups worldwide. In this study, prevalence of asymptomatic norovirus infection was investigated in food handler being employed at food catering facilities in South Korea. A total of 2,729 fecal specimens from asymptomatic food handlers were analyzed, and 1.06% of food handlers (29/2,729) had asymptomatic NoV infection. Of these, 17.2% (5/29) were positive for NoV GI and 82.7% (24/29) were positive for NoV GII. Especially, sequencing and phylogenetic analysis showed that GII-4 was the most prevalent genotype and a large number of asymptomatic food handlers were infested with norovirus GII-4 strains. The results of this study show that asymptomatic food handlers may be potential transmission sources for NoV infection. These results emphasize the need for training of food catering employees about norovirus prevention. Asymptomatic norovirus infection should receive more attention.

• Clinical and Experimental Pediatrics
• /
• v.53 no.1
• /
• pp.14-20
• /
• 2010

Cytomegalovirus (CMV) is currently the most common agent of congenital infection and the leading infectious cause of brain damage and hearing loss in children. Symptomatic congenital CMV infections usually result from maternal primary infection during early pregnancy. One half of symptomatic infants have cytomegalic inclusion disease (CID), which is characterized by involvement of multiple organs, in particular, the reticuloendothelial and central nervous system (CNS). Moreover, such involvement may or may not include ocular and auditory damage. Approximately 90% of infants with congenital infection are asymptomatic at birth. Preterm infants with perinatal CMV infection can have symptomatic diseases such as pneumonia, hepatitis, and thrombocytopenia. Microcephaly and abnormal neuroradiologic imaging are associated with a poor prognosis. Hearing loss may occur in both symptomatic and asymptomatic infants with congenital infection and may progress through childhood. Congenital infection is defined by the isolation of CMV from infants within the first 3 weeks of life. Ganciclovir therapy can be considered for infants with symptomatic congenital CMV infection involving the CNS. Pregnant women of seronegative state should be counseled on the importance of good hand washing and other control measures to prevent CMV infection. Heat treatment of infected breast milk at $72{^{\circ}C}$ for 5 seconds can eliminate CMV completely.

• Journal of Korean Neurosurgical Society
• /
• v.47 no.4
• /
• pp.265-270
• /
• 2010

Objective : The purpose of this study is to identify the relationship between asymptomatic urinary tract infection (aUTI) and postoperative spine infection. Methods : A retrospective review was done in 355 women more than 65 years old who had undergone laminectomy and/or discectomy, and spinal fusion, between January 2004 and December 2008. Previously postulated risk factors (i.e., instrumentation, diabetes, prior corticosteroid therapy, previous spinal surgery, and smoking) were investigated. Furthermore, we added aUTI that was not previously considered. Results : Among 355 patients, 42 met the criteria for aUTI (Bacteriuria ${\geq}\;10^5\;CFU/mL$ and no associated symptoms). A postoperative spine infection was evident in 15 of 355 patients. Of the previously described risk factors, multi-levels (p<0.05), instrumentation (p<0.05) and diabetes (p<0.05) were proven risk factors, whereas aUTI (p>0.05) was not statistically significant. However, aUTI with Foley catheterization was statistically significant when Foley catheterization was added as a variable to the all existing risk factors. Conclusion : aUTI is not rare in elderly women admitted to the hospital for lumbar spine surgery. The results of this study suggest that aUTI with Foley catheterization may be considered a risk factor for postoperative spine infection in elderly women. Therefore, we would consider treating aUTI before operating on elderly women who will need Foley catheterization.

• Journal of fish pathology
• /
• v.23 no.1
• /
• pp.17-25
• /
• 2010

We have identified an iridovirus CH-1 from sea perch Lateolabrax sp. healthy externally and imported from China to Korea. In a comparison of the nucleotide sequences of the five different genomic regions, the CH-1 appears to be closely related to the ISKNV, IVS-1 and Ehime-1 strains detected in China, Korea and Japan respectively. In quantitative comparison of the viral DNA, level of CH-1 in tissue of imported fish was 10,000 times lower than that of IVS-1 strain presented in the infected rock bream Oplegnathus fasciatus of moribund stage. It allowed us to speculate the possibility of the asymtomatic iridovirus infection in the culturing sea perch. Such possibility of asymptomatic infection was supported by result of no appearance of dead fish with typical symptoms of iridoviral disease in keeping experiment of the imported sea pearch in laboratory for more than three weeks. Such asymptomatic infections with iridovirus were also found in spleen of the culturing and externally healthy sea perch of Korea by the presence of the iridoviral DNA in nested PCR.

• The Journal of Korean Medicine
• /
• v.42 no.1
• /
• pp.99-109
• /
• 2021

Objectives: Objective: The purpose of this study is to investigate the treatment of herbal medicine for patients with COVID-19 asymptomatic infections. Method: In English, search engines such as 'PubMed', 'Science Direct', and 'Cumulative Index to Nursing and Allied Health Literature (CINAHL)' were used. In Chinese, search engines such as 'China National Knowledge Infrastructure (CNKI)' and Wanfang were used. The keywords for the search engines were 'COVID-19', 'asymptomatic infection', 'Korean Medicine', 'traditional Chinese medicine', 'herbal medicine', and etc. Only clinical studies using herbal medicine for patients without fever or respiratory symptoms were selected. We excluded the cases that do not fit the research topic. Results: A total of 5 studies were finally selected. Among them, four of them used integrated herbal medicine and Western medicine, and one of the studies treated exclusively for herbal medicine. There were a total of seven prescriptions for herbal medicine used in the study. Outcome variables were used as following: lab test, nucleic acid conversion time, hospitalization period, chest CT, and etc. In the RCT study, herbal medicine and Western medicine decreased nucleic acid conversion time, average hospitalization time compared to the control group, but it was not statistically significant. No other adverse reactions were reported in all studies. Conclusion: According to the results, integrated herbal medicine and Western medicine might be an effective treatment for patients with COVID-19 asymptomatic infection reducing hospitalization period, time of nucleic acid turning negative. No severe adverse effects were reported. However, it is thought that better-designed research will be needed in the future.

• Journal of Microbiology and Biotechnology
• /
• v.27 no.5
• /
• pp.1005-1009
• /
• 2017

Primary cytomegalovirus (CMV) infection during pregnancy can cause congenital defects. Available data for CMV infection during pregnancy in north China are inadequate. The aim of this study was to evaluate the epidemiology of maternal CMV infection and explore the incidence of congenital infection. In this prospective study, serum CMV IgG and IgM antibodies were measured in 2,887 pregnant women using ELISA, and the IgG avidity test was performed on all IgM-positive subjects. The seroprevalence of anti-CMV IgG was 94.70%, and of anti-CMV IgM was 1.28%. CMV IgG prevalence increased significantly with age (p < 0.01). Women living in downtown areas showed higher IgG prevalence than those residing in urban areas (p = 0.023). CMV-IgM seroprevalence was highest in autumn (p = 0.021). There was no difference in IgM seroprevalence by age, socioeconomic status, geographical area, or gravida. The rate of primary CMV infection was 0.45% (13/2,887) at the first trimester. The seroconversion rate during pregnancy was 0.76% (22/2,887). One woman underwent seroconversion during pregnancy and gave birth to an infant with asymptomatic CMV infection. Congenital CMV infection was diagnosed in five of the 14 infants from 14 mothers with active infection, for a vertical transmission rate of 35.71% (5/14). Three infants were asymptomatic, whereas two infants presented symptomatic infection with hearing deficits. Although CMV IgG prevalence is relatively high in north China, significant attention to primary CMV infection during pregnancy is still needed.

• The Microorganisms and Industry
• /
• v.13 no.3
• /
• pp.3-11
• /
• 1987

Hepatitis B virus (HBV) is a very serious threat to public health in most of the developing countries of the world. It is estimated that around 300 million people worldwide are chronic carriers of this virus and will transmit the disease both vertically and horizontally. Infection by this virus may cause a wide range of clinical manifestations ranging from an asymptomatic infection to liver cirrhosis.

• Journal of Yeungnam Medical Science
• /
• v.34 no.2
• /
• pp.231-237
• /
• 2017

Background: Deep vein thrombosis (DVT) and pulmonary embolism (PE) are conditions with significant morbidity and mortality. Proximal DVT has a significant association with PE and possible fatal outcomes. Traditionally, PE is subdivided into symptomatic PE and asymptomatic PE, which have different treatments, preventions and prognoses. The growing utilization of computed tomography pulmonary angiography has led to increased detection of PE in DVT patients. This study examined the clinical characteristics and compared symptomatic PE and asymptomatic PE following proximal DVT. Methods: The medical records of 258 DVT inpatients from July, 2012 to June, 2015 were reviewed retrospectively. After excluding the patients who did not performed PE evaluation and were not diagnosed with PE, 95 patients diagnosed with PE following proximal DVT were enrolled in this study. They were divided into the symptomatic PE group and asymptomatic PE group. Results: The body weight, body mass index, thrombus size, thrombus length and location were similar in the two groups. The symptomatic PE following proximal DVT group showed an older age, higher incidence of emergency department access (85.0% vs. 38.7%, p<0.001) and preceding infection (25.0% vs. 1.3%, p<0.001) as well as a higher incidence of immobilization (45.0% vs 13.3%, p=0.016). In the multivariate logistic regression study, preceding infection and emergency department access showed significant association with symptomatic PE. Conclusion: In proximal DVT inpatients, symptomatic PE was associated with emergency department access and preceding infection. The possibility of a symptomatic PE event should be considered in proximal DVT patients, especially those who were admitted through the emergency department and had preceding infection.