Krebs1966). when sampling regularity was less than monthly. Effort necessary to Demethoxycurcumin detect temporal dynamics of SNV differed from effort to detect demographic patterns in deer mouse abundance. Findings here are applicable to sampling strategies for other hostpathogen dynamics and have direct implications for allocation of public health resources and intervention programs. Key Words:emerging infectious disease, hantavirus,Peromyscus maniculatus, population dynamics, sampling interval, Sin Nombre virus, wildlife diseases, zoonoses == Introduction == Reports of novel emergingand resurging wildlife and zoonotic infectious diseases have increased in recent decades (Berger et al.1998, Jones et al.2008, Blehert et al.2009). Consequently, interest in these types of diseases among ecologists, wildlife biologists, and, in the case of zoonoses, public health scientists and practitioners has grown (Gortazar et al.2007). IL1R1 antibody In relevant cases, sampling of pathogens has been integrated into existing and newly established wildlife-monitoring programs: for example, Sin Nombre virus (SNV) (Mills et al.1999a,1999b), Ross River virus (Carver et al.2008), and amphibian chytrid fungus (Berger et al.1998, Bell et al.2004). Despite direct implication to human exposure risk and health, however, the effect of sampling frequency on coupled interpretations of wildlife and zoonotic pathogen dynamics has received little empirical attention. Here we evaluate how a reduction in sampling frequency influences our ability to detect fluctuations in abundance of deer mice,Peromyscus maniculatus; the infection dynamics Demethoxycurcumin of a directly transmitted zoonotic virus, SNV (Bunyaviridae:Hantavirus; an agent of hantavirus pulmonary syndrome [HPS] that causes severe morbidity and mortality in humans); and implications this may have to interpretation of human exposure risk. Populations of hosts that are capable of high levels of fecundity, such as deer mice, can exhibit extreme changes in abundance over brief periods (Krebs1966,1996, Singleton1989). The use of infrequent sampling (i.e., seasonal or semiannual) to monitor population abundance of small mammals, such as deer mice, is common (e.g., Saitoh et al.1999, Strann et al.2002, Flowerdew et al.2004, Larsen et al.2007). In some Demethoxycurcumin instances studies using infrequent sampling of small mammals also extend to examination of wildlife (e.g., Cavanagh et al.2004) or zoonotic pathogens (e.g., Carver et al.2008) among individuals comprising reservoir Demethoxycurcumin populations, such as for hantaviruses in their rodent hosts (Biggs et al.2000a,2000b, Escutenaire et al.2000, Olsson et al.2003, Pearce-Duvet et al.2006). Potentially, the frequency of Demethoxycurcumin sampling necessary to describe dynamics of deer mouse populations may differ from the frequency needed to describe dynamics of SNV infection. For example, bi-monthly trapping of deer mice may adequately detect their population fluctuations [due to an approximate 12-month lag between the birth of pups and first detection by trapping (King et al.1963, Kirkland and Layne1989)], whereas a monthly trapping interval may be necessary to detect the dynamics of SNV transmission [due to a 24-week time interval between infection and detection of SNV IgG antibody in deer mice (Botten et al.2000,2002)]. Accordingly, it is possible that the sampling interval that is adequate to quantify deer mouse population demographics may be longer than what is necessary to capture dynamics of SNV infection. If the frequency of sampling does not adequately capture both deer mouse population demographics and SNV dynamics, it could lead to erroneous conclusions about hostpathogen relationships and, by extension, sub-optimal management and health interventions. We use a longitudinal study of deer mouse populations and prevalence of antibody to SNV, which we have conducted monthly (19942008) at three trapping grids near Cascade, Montana (Douglass et al.1996,2001). We simulate variable sampling frequencies by selective deletion of sampling occasions from this study, and recalculation of deer mouse abundance and prevalence of antibody to SNV. We ask three questions: (1) How does a reduction in sampling frequency influence our ability to detect fluctuations in deer mouse populations and SNV infection dynamics in the field? (2) Can a sampling schedule, which adequately represents the dynamics of a host (deer mice), be generalized to a pathogen (SNV)? (3) How frequently are annual peaks and troughs in population abundance and infection prevalence missed by sampling less frequently? The direct implication of these results to investment in public health campaigns or interventions and human HPS exposure risk is discussed. == Materials and Methods == This investigation was conducted on three live trapping grids (grid numbers 10, 11, and 12) located near Cascade (4659.3 N, 11135.3 W, 1408 m Average Mean Sea.