[Serotype determination of enteroviruses that cause hand-foot-mouth disease; identification of enterovirus 71 and coxsackievirus A16 from clinical specimens by using specific probe]

Ferroptosis, from the virus point of view: opportunities and challenges

Ferroptosis is a new type of cell death, which is mainly dependent on the formation and accumulation of reactive oxygen species and lipid peroxides mediated by iron. It is distinct from other forms of regulation of cell death in morphology, immunology, biochemistry, and molecular biology. Various cell death mechanisms have been observed in many viral infections, and virus-induced cell death has long been considered as a double-edged sword that can inhibit or aggravate viral infections. However, understanding of the role of ferroptosis in various viral infections is limited. Special attention will be paid to the mechanisms of ferroptosis in mediating viral infection and antiviral treatment associated with ferroptosis. In this paper, we outlined the mechanism of ferroptosis. Additionally, this paper also review research on ferroptosis from the perspective of the virus, discussed the research status of ferroptosis in virus infection and classified and summarized research on the interaction between viral infections and ferroptosis.

Molecular epidemiology of Echovirus 30 in Taiwan, 1988-2008

To investigate the molecular epidemiology of Taiwanese Echovirus 30 (E-30) strains, we analyzed the 876 bp sequence of the VP1 gene from 32 Taiwanese strains isolated in 1988-2008, 498 reference sequences, and one Echovirus 21 strain as the out-group. Phylogenetic analysis detected six E-30 genotypes (designated GI-GVI) that had circulated globally during the past five decades. The genotypes varied widely in geographic distribution and circulation half-life. The GI, GII, and GV were ancient genotypes in which the first strains emerged in the 1950s. The GIII was a reemerging genotype, in which strains had first appeared in Colombia in 1995 before reemerging in the New Independent States (NIS) in 2003. The GIV, an emerging genotype that recently appeared in Asia in 2003, was closely related to the ancient genotypes. The GVI was the circulating genotype, which included eight clusters (A-H) that had circulated since 1967. No GVI-A, C, D, or E strains have been identified during the past 10 years. The GVI-B first appeared in China in 1984 and later in Russia and Asia in the 2000s. The GVI-F, G, and H strains, which comprised the prevalent clusters, had been dominant in Asia Pacific area, globally, and Europe, respectively. Taiwanese strains were classified into GVI-D (1988-1989), GVI-F (1993-2004), and GVI-G (1993-2008). The quiescence period of E-30 is longer in Taiwan (5-8 years) than in other countries (3-5 years).

Epidemiologic features of hand-foot-mouth disease and herpangina caused by enterovirus 71 in Taiwan, 1998-2005

OBJECTIVE

In 1998, an epidemic of hand-foot-mouth disease/herpangina was caused by human enterovirus 71 infection in Taiwan. The underlying factors of widespread emergence of viral infection are unclear. The purpose of this study was to assess the epidemiology of hand-foot-mouth disease/herpangina in Taiwan between March 1998 and December 2005.

METHODS

We analyzed data reported to surveillance systems at the Taiwan Center for Disease Control. Viral isolation was performed by 11 reference virus laboratories at medical centers as well as the Taiwan Center for Disease Control.

RESULTS

During the 8-year study period, the reported incidence of mild cases of hand-foot-mouth disease/herpangina varied from 0.8 to 19.9 cases per sentinel physician per week, peaking in 1998. Seasonal variations in incidence were observed, with an incidence peak observed during the summer season. Annual incidence changed significantly from 1998 to 2005. Both age-specific incidence and fatality of severe hand-foot-mouth disease/herpangina decreased as age increased. Most (93%) cases occurred in children who were aged 4 years and younger. Inpatients had a higher rate of enterovirus 71 infection than outpatients. Among severe cases, the majority (80%) had pulmonary edema/hemorrhage and encephalitis.

CONCLUSIONS

Hand-foot-mouth disease/herpangina is a common disease in Taiwan. Enterovirus 71 infection has emerged as an important public problem causing serious clinical illness and, potentially, death in young children. Vaccine development is recommended for prevention of enterovirus 71 infection in the future.

Serotype-specific identification of enterovirus 71 by PCR

BACKGROUND

Enterovirus 71 and coxsackievirus A16 are closely related genetically and are causative agents of hand foot and mouth disease. Because enterovirus 71 is more often associated with severe neurological disease, there is a need to rapidly discriminate between enterovirus 71 and coxsackievirus A16 during hand, foot, and mouth disease outbreaks.

OBJECTIVES

Our goal was to develop and evaluate a serotype-specific reverse transcription-polymerase chain reaction (RT/PCR)-based typing method for enterovirus 71.

STUDY DESIGN

Two sets of PCR primers were designed to match conserved amino acid intervals of enterovirus 71. One diagnostic primer pair contains deoxyinosine at sites of 4-fold codon degeneracy. A second primer pair was designed for use in sequencing and molecular epidemiology studies. Primer pairs were tested on strains encountered in routine diagnostic samples.

RESULTS

Using both sets of primers on a panel of 61 prototype enteroviral strains, both primer pairs gave strong positive signals for only enterovirus 71. These primers amplified all enterovirus 71 isolates tested and discriminated between enterovirus 71 and the most closely related enterovirus, coxsackievirus A16.

CONCLUSIONS

Our RT-PCR assay can be used for specific identification of enterovirus 71 clinical isolates. Furthermore, the 484-bp product of one primer pair has proven useful in sequencing studies to identify distinct genotypes of enterovirus 71.