Seoul hantavirus in brown rats in the Netherlands: implications for physicians--Epidemiology, clinical aspects, treatment and diagnostics.

The recent discovery of Seoul hantavirus (SEOV) presence in wild rat populations in the Netherlands has direct implications for Dutch clinicians and hantavirus diagnostics. SEOV is amongst the Old World hantaviruses which cause haemorrhagic fever and renal syndrome (HFRS) in humans. HFRS is characterised by a classical triad of fever, acute kidney injury and haemorrhage, but can show different signs and symptoms in specific cases. SEOV is transmitted from infected rats to humans by inhalation of aerosolised excreta. When compared with the known circulating hantaviruses in the Netherlands, Puumala (PUUV) and Tula (TULV), SEOV causes a more severe form of HFRS. Data from cohort studies undertaken in China and Northern Europe show differences in signs and symptoms at onset of disease, (haemorrhagic) complications and mortality. Furthermore, routine diagnostics currently available for hantavirus diagnosis in the Netherlands are not optimised for SEOV detection. The clinical outcome of an SEOV and PUUV infection will greatly benefit from an early diagnosis which will reduce the costs of unnecessary tests and treatments as well. The discovery of SEOV circulation in the Netherlands follows recent findings of SEOV infections in both rodents and humans in England, Wales, France, Belgium and Sweden, indicating the emerging character of SEOV and a high importance of this hantavirus for Public Health in large areas of Europe. Here, we review the current knowledge on the clinical manifestation of SEOV versus PUUV infections in humans, the treatment of clinical cases and diagnostics.

Early-life rotavirus and norovirus infections in relation to development of atopic manifestation in infants.

BACKGROUND: The increase in incidence of atopic diseases (ADs) in the developed world over the past decades has been associated with reduced exposure of childhood infections. OBJECTIVE: To investigate the relation between early intestinal viral infections in relation to the development of atopic symptoms (eczema, wheeze and atopic sensitization) in the first and second year(s) of life. METHODS: In the KOALA Birth Cohort Study, we assessed IgG seropositivity for rota- and norovirus (GGI.1 and GGII.4) at 1 year of age. This was related to allergic sensitization [specific immunoglobulin E (IgE)] at 1 and 2 years, and parent reported eczema and wheeze in the first 2 years, using logistic regression analysis adjusted for confounders. RESULTS: Rotavirus seropositivity (39%) was associated with an unexpected higher risk of recurrent wheeze in the first and second year of life [adjusted odds ratio (OR) 3.1 and 95% confidence intervals (CI) 1.1-9.1] and persistent and new recurrent wheeze (adjusted OR 2.7 and 95% CI 1.1-6.2). No further associations were found between intestinal viral seropositivity and atopic manifestations. CONCLUSION: Our data did not show a clear protection by enteric viral infections in young children on development of IgE response to allergens, but rotavirus infection in the first year was a risk factor for wheeze. However, this needs to be followed up to older ages in order to establish the true importance of intestinal viral infections and especially cumulative effects in AD aetiology. Exposure to rotavirus may offer a new and interesting focus on infant wheeze and later asthma development.

Experimental norovirus infections in non-human primates.

Noroviruses, with Norwalk virus as the prototype strain, are the most common cause of viral gastroenteritis in people of all ages. Limited information on the immunology of Norovirus infections has been obtained by studies both in the natural setting and in experimentally infected volunteers. Interpretation of these studies is difficult due to the lack of information on the history of Norovirus exposure and the cross-reactivity of antibodies. An animal model for Norovirus infections would be important to study the immune response, e.g., for vaccine assessment. In the present study the susceptibility of common marmosets, cotton top tamarins, cynomolgus, and rhesus macaques to Norovirus infection was tested. Following oral inoculation, low level replication may have occurred in common marmosets and cotton top tamarins but not in cynomolgus macaques, based on short-term viral shedding; neither clinical symptoms nor antibody responses were observed in these species. In contrast, rhesus macaques were found susceptible to Norwalk virus infection as one animal shed virus for a longer period of time and developed Norwalk virus specific IgM and IgG responses. Further research on Norovirus susceptibility in rhesus macaques may yield an animal model to study the immune response and pathogenesis after Norovirus infection.