Virology: Research and Treatment最新文献

Zika virus (ZIKV) is a mosquito-borne arbovirus from the family Flaviviridae, which had caused some epidemics since its discovery in 1947 without any significant impacts on public health. In 2015, however, a 20-fold increase in congenital microcephaly cases in northeastern Brazil was attributed to prenatally acquired ZIKV infection. Traditionally, TORCH agents have 4 common characteristics including causing a mild illness in infected mother, vertical transmission to fetus, developing several anomalies in the affected fetus, and in some instances, maternal therapy may not ameliorate fetal prognosis. Prenatal ZIKV infection has shown the aforementioned characteristics during the recent epidemics in South America and the Caribbean region; therefore, it should be considered as an emerging TORCH agent that may seriously threaten public health. Fetal ultrasound can be used as a safe, inexpensive, and easy-to-access imaging modality for detecting suspicious cases of congenital Zika syndrome in utero and suggesting confirmatory diagnostic examinations to these patients.

Dengue disease is an emerging mosquito-borne viral infection transmitted between humans by Aedes spp. that are distributed mainly in the tropical and subtropical region along with chikungunya and zika diseases. The distribution of dengue disease is influenced by local variation, such as geography, rainfall, temperature, and rapid urbanization or migration. The epidemy of mosquito-borne infection significantly led to increased number of cases and hyperendemicity which induce a more severe form of dengue accompanied by cocirculation of chikungunya and zika. The rapid global spreading of dengue disease created public health burdens that are presently unfulfilled by the absence of specific therapy, simple diagnosis tool for the early phase, and effective and efficient vector control system. This review highlights the current situation of dengue distribution, epidemiology, and new strategies for early dengue diagnosis and risk prediction of severity that can be used to improve oversight and alleviate the heavy burden of the disease.

Background: Threat to blood transfusion-transmitted dengue virus (DENV) and its antibodies has recently emerged worldwide. Dengue fever is an endemic disease in Saudi Arabia, particularly in its Western region. The aim of this study was to estimate the seroprevalence of asymptomatic DENV infection and its antibodies among eligible Saudi blood donors.

Methods: Serum samples from 910 healthy/eligible adult male Saudi blood donors, who reside in Holy Makkah City of Saudi Arabia, were collected between March 2015 and August 2016 and screened for the detection of DENV nonstructural protein 1 (NS1) antigen and anti-DENV IgM and IgG antibodies using commercial enzyme-linked immunosorbent assay kits (Panbio, Brisbane, QLD, Australia).

Results: Among the tested donors, 48 (5.3%) were seropositive for DENV-NS1 antigen, whereas 50 (5.5%) and 354 (38.9%) were seropositive for anti-DENV IgM and IgG antibodies, respectively. Seropositivity for DENV-NS1 antigen and/or anti-DENV IgM antibody among the tested donors reflects their ongoing asymptomatic viremic infectious stage with DENV during their donation time, whereas high prevalence of anti-DENV IgG seropositivity reflects the high endemicity of dengue disease in this region of Saudi Arabia.

Conclusions: These results show high prevalence of asymptomatic DENV infection and its antibodies among Saudi blood donors, raising the importance of establishing blood screening for dengue disease at different blood donation services and units in Saudi Arabia to improve the guarantee of blood transfusions and to control DENV dissemination.

Hepatitis C virus (HCV) infection is a major health problem recognized globally. HCV is a common cause of liver fibrosis that may lead to liver cirrhosis or hepatocellular carcinoma. The aim of this study was to estimate the prevalence of HCV infection and genotyping among Egyptian and Saudi Arabian chronic patients using different molecular techniques. HCV RNA viral load was assessed by real-time polymerase chain reaction (RT-PCR) technology. For HCV genotyping, RT-PCR hybridization fluorescence-based method and reverse hybridization line probe assay (INNO-LiPA) were used. A total of 40 anti-HCV-positive patients with chronic hepatitis C were examined for HCV RNA, genotyping, and different laboratory investigations. In the present study, HCV genotypes 4, mixed 4.1b, and 1 were detected in patients of both countries, while genotype 2 was only detected in Saudi Arabian patients. Genotyping methods for HCV showed no difference in the classification at the genotype level. With regard to HCV subtypes, INNO-LiPA assay was a reliable test in HCV genotyping for the detection of major genotypes and subtypes, while RT-PCR-based assay was a good test at the genotype level only. HCV genotype 4 was found to be the predominant genotype among Egyptian and Saudi Arabian chronic patients. In conclusion, data analysis for detecting and genotyping HCV was an important factor for understanding the epidemiology and treatment strategies of HCV among Egyptian and Saudi Arabian chronic patients.

A cross-sectional study in Nigeria was undertaken to determine the epidemiology, seroprevalence, and associated risk factors, of hepatitis E virus (HEV). A total of 462 subjects were used for the study, categorized into four groups: apparently healthy persons, pregnant women, HIV positive subjects, and animal handlers. Information was obtained from subjects using interviewer-administered questionnaire. Blood samples were collected and analyzed for HEV antibodies (IgG and IgM) using enzyme-linked immunosorbent assay (ELISA) technique. Results obtained were analyzed using Statistical Package for Social Sciences (SPSS) version 17.0 statistical software. The overall seroprevalence of IgG and IgM was 42.7 and 0.9%, respectively. Animal handlers had the highest seroprevalence (66.7%). The associated risk factors for IgM seroprevalence were rural dwelling (P = 0.039, odds ratio (OR) 3.3, 95% confidence interval (CI) 0.7-15.4), blood transfusion (P < 0.001, OR 9.6, 95% CI 2.6-35.6), attending to animals (P = 0.032, OR 4.9, 95% CI 0.9-26.6), and waste disposal (P < 0.001). Factors associated with IgG were age (P = 0.044), location (P < 0.001), marital status (P < 0.001), formal education (P < 0.001), farming as occupation (P < 0.001), rural dwelling (P = 0.001), waste disposal (P < 0.001), alcohol consumption (P = 0.001, OR 2.4, 95% CI 1.4-4.0), open defecation (P < 0.001, OR 2.9, 95% CI 1.4-5.7), attending to animals (P < 0.001, OR 2.3, 95% CI 1.6-3.4), consuming unwashed fruits/vegetables (P < 0.001, OR 4.2, 95% CI 0.3-54.1), and stream/river as a source of drinking water (P < 0.001, OR 3.6, 95% CI 1.6-7.8). Preventive public health measures should be reinforced among all communities, particularly domestic animal handlers and pregnant women. Potable water should be provided for all communities. Data suggest that HEV remains an under-recognized and significant public health problem, warranting further attention and research.

Background: Viral diarrhea continues to be a health problem in Indonesia that often causes outbreaks; in particular, acute viral diarrhea in young children. Rotavirus is the leading cause of severe diarrhea in children under two years of age. This study aimed to determine the genotypes of rotavirus in Bintuni Bay, Papua.

Methods: Stool specimens from 15 patients were collected and analyzed for rotavirus using an enzyme immunosorbent assay (EIA) and reverse transcriptase-polymerase chain reaction (RT-PCR). Subsequently, we sequenced the genetic material of rotavirus positive samples by RT-PCR and analyzed the results using Mega-4 software.

Results: Two rotavirus serotypes were identified from the diarrhea outbreak in Bintuni, Papua in October 2008: serotype G1 with G1P[6] (50%) and G1P[8] (16.7%) strains, and serotype G2 with G2P[4] (23.3%) strain. Phylogenetic tree analyses of VP7 protein showed that rotavirus-infected diarrhea in Bintuni Bay, Papua at that time was dominated by the G1 serotype (83%).

Conclusion: The laboratory results showed that G1 serotype rotavirus was a cause of the outbreak of diarrhea in October 2008 in Bintuni, Papua.

Almost 7 million children under the age 5 die each year, and most of these deaths are attributable to vaccine-preventable infections. Young infants respond poorly to infections and vaccines. In particular, dendritic cells secrete less IL-12 and IL-18, CD8^pos T cells and NK cells have defective cytolysis and cytokine production, and CD4^pos T cell responses tend to bias towards a Th2 phenotype and promotion of regulatory T cells (T_regs). The basis for these differences is not well understood and may be in part explained by epigenetic differences, as well as immaturity of the infant's immune system. Here we present a third possibility, which involves active suppression by immune regulatory cells and place in context the immune suppressive pathways of mesenchymal stromal cells (MSC), myeloid-derived suppressor cells (MDSC), CD5^pos B cells, and T_regs. The immune pathways that these immune regulatory cells inhibit are similar to those that are defective in the infant. Therefore, the immune deficiencies seen in infants could be explained, in part, by active suppressive cells, indicating potential new avenues for intervention.