The persistence of 3 low-pathogenicity avian influenza viruses (LPAIV) (H4N6, H5N1, and H6N8) and one human influenza virus (H1N1) as well as Newcastle disease virus (NDV) and enteric cytopathogenic bovine orphan (ECBO) virus was investigated in lake sediment, duck feces, and duck meat at 30, 20, 10, and 0°C using a germ carrier technique. Virus-loaded germ carriers were incubated in each substrate, and residual infectivity of the eluted virus was quantified on cell culture after regular intervals for a maximum of 24 weeks. Data were analyzed by a linear regression model to calculate T 90 values (time required for 90% loss of virus infectivity) and estimated persistence of the viruses. In general, the persistence of all of the viruses was highest in lake sediment, followed by feces, and was the lowest in duck meat at all temperatures. For the avian influenza virus subtypes, T 90 values in sediment ranged from 5 to 11, 13 to 18, 43 to 54, and 66 to 394 days at 30, 20, 10, and 0°C, respectively, which were 2 to 5 times higher than the T 90 values of the viruses in the feces and meat. Although the individual viruses vary in tenacity, the survival time of influenza viruses was shorter than that of NDV and ECBO virus in all substrates. The results of this study suggest that lake sediment may act as a long-term source of influenza viruses in the aquatic habitat, while the viruses may remain infectious for extended periods of time in duck feces and meat at low temperatures, allowing persistence of the viruses in the environment over winter.

The tenacity of three low pathogenicity avian influenza viruses (AIV; subtypes H4N6, H5N1, and H6N8) was tested at five different temperatures (-10, 0, 10, 20, and 30 C) in distilled water, normal saline, and surface water obtained from Lake Constance. Infectivity of AIV in the samples was quantified at regular intervals by end point titration on Madin-Darby canine kidney cells for a maximum period of 36 wk, and duplicate samples were tested each time. The results showed that the survival time of AIV in all of the water types was inversely proportional to storage temperature. All three viruses showed varying sensitivity to inactivation under each of the experimental conditions. Persistence of the viruses was the longest in distilled water, second longest in normal saline, and shortest in surface water. The virus-inoculated surface water remained infective for a few days at 30 and 20 C, a few weeks at 10 C, and for months at 0 and -10 C.

Noroviruses (NV), in the family Caliciviridae, are an important cause of gastroenteritis in humans worldwide. Measures for prevention and control of NV dissemination are therefore necessary to ensure public safety. The abilities of an organic acid (Venno Vet 1 Super), an aldehyde (Venno FF Super), a halogen compound (sodium hypochlorite solution), and a peroxide (Oxystrong FG) to inactivate feline calicivirus (FCV), a cultivable virus surrogate for NV, were studied. Molecular protocols were then used for the comparative evaluation of disinfectant efficacies against NV and FCV, which were tested by reproducing NV field conditions, using human fecal material as a protein load. Generally, disinfectant efficacy was strongly reduced by the organic impurities (feces) used during tests. All disinfectants, except the aldehyde, were effective on FCV, as measured by cell culture and reverse transcription-PCR (RT-PCR), with inactivation levels of >99.9%. The glutaraldehydebased compound failed to adequately inactivate FCV according to RT-PCR results, although the infectivity in cell culture was completely abolished. Similar inactivation levels were achieved with NV, but generally NV appeared more resistant than FCV, and consequently, the suitability of FCV as a model for NV should be considered with caution. In conclusion, according to RT-PCR results, 5% Venno Vet 1 Super, 1% Oxystrong FG, and not less than 2% Venno FF Super, with a contact time of 1 h, and 1% sodium hypochlorite, with 6,000 ppm of free chlorine and a contact time of 15 min, are required for safe disinfection when a calicivirus-related outbreak is suspected.

The identification and molecular epidemiology of norovirus in outbreaks of gastroenteritis were studied during a 3-year period in Germany. Specimens (

Herpes simplex virus (HSV) infections are among the most common viral infections and usually last for a lifetime. The virus can potentially be controlled with vaccines since humans are the only known host. However, despite the development and trial of many vaccines, this has not yet been possible. This is normally attributed to the high latency potential of the virus. Numerous immune cells, particularly the natural killer cells and interferon gamma and pathways that are used by the body to fight HSV infections have been identified. On the other hand, the virus has developed different mechanisms, including using different microRNAs to inhibit apoptosis and autophagy to avoid clearance and aid latency induction. Both traditional and new methods of vaccine development, including the use of live attenuated vaccines, replication incompetent vaccines, subunit vaccines and recombinant DNA vaccines are now being employed to develop an effective vaccine against the virus. We conclude that this review has contributed to a better understanding of the interplay between the immune system and the virus, which is necessary for the development of an effective vaccine against HSV.