No abstract

Until recently, human coronaviruses (HCoVs), such as HCoV strain OC43 (HCoV-OC43), were mainly known to cause 15 to 30% of mild upper respiratory tract infections. In recent years, the identification of new HCoVs, including severe acute respiratory syndrome coronavirus, revealed that HCoVs can be highly pathogenic and can cause more severe upper and lower respiratory tract infections, including bronchiolitis and pneumonia. To date, no specific antiviral drugs to prevent or treat HCoV infections are available. We demonstrate that chloroquine, a widely used drug with well-known antimalarial effects, inhibits HCoV-OC43 replication in HRT-18 cells, with a 50% effective concentration (؎ standard deviation) of 0.306 ؎ 0.0091 M and a 50% cytotoxic concentration (؎ standard deviation) of 419 ؎ 192.5 M, resulting in a selectivity index of 1,369. Further, we investigated whether chloroquine could prevent HCoV-OC43-induced death in newborn mice. Our results show that a lethal HCoV-OC43 infection in newborn C57BL/6 mice can be treated with chloroquine acquired transplacentally or via maternal milk. The highest survival rate (98.6%) of the pups was found when mother mice were treated daily with a concentration of 15 mg of chloroquine per kg of body weight. Survival rates declined in a dose-dependent manner, with 88% survival when treated with 5 mg/kg chloroquine and 13% survival when treated with 1 mg/kg chloroquine. Our results show that chloroquine can be highly effective against HCoV-OC43 infection in newborn mice and may be considered as a future drug against HCoVs.

Hepatitis C virus (HCV) genotyping is a tool used to optimize antiviral treatment regimens. The newly developed Versant HCV genotype assay (LiPA) 2.0 uses sequence information from both the 5 untranslated region and the core region, allowing distinction between HCV genotype 1 and subtypes c to l of genotype 6 and between subtypes a and b of genotype 1. HCV-positive samples were genotyped manually using the Versant HCV genotype assay (LiPA) 2.0 system according to the manufacturer's instructions. For the comparison study, Versant HCV genotype assay (LiPA) 1.0 was used. In this study, 99.7% of the samples could be amplified, the genotype of 96.0% of samples could be determined, and the agreement with the reference method was 99.4% when a genotype was determined. The reproducibility study showed no significant differences in performance across sites (P ‫؍‬ 0.43) or across lots (P ‫؍‬ 0.88). In the comparison study, 13 samples that were uninterpretable or incorrectly genotyped with Versant HCV genotype assay (LiPA) 1.0 were correctly genotyped by Versant HCV genotype assay (LiPA) 2.0. Versant HCV genotype assay (LiPA) 2.0 is a sensitive, accurate, and reliable assay for HCV genotyping. The inclusion of the core region probes in Versant HCV genotype assay (LiPA) 2.0 results in a genotyping success rate higher than that of the current Versant HCV genotype assay (LiPA) 1.0.

Epidemiological and phylogenetic studies of hepatitis C virus (HCV) have identified six major HCV genotypes and have attempted to characterize their origin and spread worldwide. Putative regions of endemic infection have been identified for all HCV genotypes except HCV genotype 5a. Although HCV genotype 5a was previously thought to be largely restricted to the northern part of South Africa, this study reports an unexpected cluster of the genotype in West Flanders Province in Belgium. To investigate the molecular epidemiology of this cluster and of HCV genotype 5a in general, a rigorous phylogenetic analysis of Belgian and South African HCV genotype 5a samples was performed. Remarkably, the Belgian and South African strains form two distinct clusters of similar diversity. We used a Bayesian coalescent method to estimate the rate of virus spread through time for HCV genotype 5a in both regions. Our results indicate that HCV genotype 5a strains have been spreading independently in Belgium and South Africa for more than 100 years, with a rate of spread characteristic of an epidemic genotype. These findings have major implications for tracing the origin of HCV genotype 5a. Here, we speculate about the possible origins of these clusters.With an estimated 170 million people infected worldwide, hepatitis C virus (HCV) is responsible for most cases of parenteral non-A, non-B hepatitis and is therefore the leading cause of chronic liver disease and hepatocellular carcinoma (38). The virus is responsible for 10,000 deaths per year in the United States alone, and this number is expected to increase substantially in the forthcoming decades (1). HCV is a bloodborne pathogen; risk factors for infection include injecting drug use, receipt of a blood transfusion before 1990, use of inadequately sterilized medical equipment, and use of scarification and tattooing tools (14). Sexual and perinatal transmissions rarely occur, except in human immunodeficiency virus-HCV-coinfected individuals (4). A nonnegligible proportion (about 20%) of HCV infections have an "undefined" route of transmission.HCV is a small, enveloped human virus containing a singlestranded RNA genome of about 9,600 nucleotides (nt) (36). HCV displays a high degree of genetic variability (22) and is classified into six major genotypes that show sequence similarities of only 66% to 69%. Each genotype contains multiple subtypes with Ͼ75% nucleotide sequence similarity (29). In comparison, the degree of similarity among different virions in a single infected patient is Ͼ95% (11).Importantly, numerous studies have revealed a relationship between the HCV genotype and the response to interferon or pegylated interferon therapy, alone or in combination with ribavirin. Patients infected with HCV genotype 1 respond less to therapy, while patients infected with HCV type 2 or 3 show the best response (23). Since HCV genotype 5a infections are scarce, treatment responses for HCV genotype 5a are largely unknown (15). For HCV genotype 6a infections, treatment response data are als...