Sentence examples for circulation of viruses from inspiring English sources
So far, circulation of viruses from both the Eastern and Southern clusters of influenza H7N9 is restricted to avian hosts.
This study provides unique data on the circulation of viruses associated with upper respiratory tract infections in Gabon.
However, following the introduction of vaccination, the circulation of viruses may become more episodic, and those missed by vaccination may continue to remain susceptible and begin to accumulate.
However, because neither conventional case nor virologic surveillance was conducted in Brazil before the start of the measles control program in 1991, it is not possible to determine if the D6 viruses were recently introduced into Brazil by importation or if they represent continued circulation of viruses indigenous to Brazil.
Inferring dynamics from time series of confirmed influenza cases gives a clearer picture of influenza dynamics, but even this type of surveillance may miss one of the larger features of tropical influenza epidemiology, namely, that some regions in the tropics or sub-tropics may support year-round circulation of viruses (Le et al., 2013; Nelson et al., 2014).
In another approximately 25% of iterations, no cases occur despite circulation of virus for approximately 1 year.
Prepandemic circulation of virus (H1N1) in early 1918 could have caused at least some circumscribed outbreaks that elicited protection.
This late circulation of virus might be surprising because biting midges of the genus Culicoides, which reportedly transmit SBV (4 ), are not usually active during cold months.
The vole population consequently peaks the following year and stimulates an increased circulation of virus, which leads to outbreaks of human disease.
Birds sold at LPMs can originate from many regions of a country; thus, conducting surveillance for subtype H5N1 virus at these markets would probably be an effective way to monitor the circulation of virus within a country (7, 9, 10 ).
Retrospectively, serologic results suggest that the epidemic ended during the autumn of 1998, probably because further major circulation of virus was greatly reduced by the effect of the low temperature on the population density of mosquitoes.
