Anaplasma phagocytophilum Infection in Small Mammal Hosts of Ixodes Ticks, Western United States
2008

Anaplasma phagocytophilum Infection in Small Mammals

Sample size: 2121 publication Evidence: moderate

Author Information

Author(s): Janet E. Foley, Nathan C. Nieto, Jennifer Adjemian, Haydee Dabritz, Richard N. Brown

Primary Institution: University of California, Davis

Hypothesis

We sought to evaluate granulocytic anaplasmosis exposure and infection and describe the Ixodes spp. tick fauna in small mammals from central and northern coastal California.

Conclusion

The study found that certain rodent species, like tree squirrels and woodrats, are frequently infected with Anaplasma phagocytophilum, while others contribute to tick ecology without being infected.

Supporting Evidence

  • High seroprevalence was observed in northern sites.
  • Odds ratios were >1 for 4 sciurids species and dusky-footed woodrats.
  • PCR prevalence among rodents tested was 3.8%.
  • Location was an important determinant of exposure to infection.

Takeaway

The study looked at small animals in California to see if they had a germ that can make people sick, and found that some animals carry the germ while others just help the ticks that spread it.

Methodology

Small mammals were trapped and tested for Anaplasma phagocytophilum using serological assays and PCR.

Potential Biases

Potential bias due to the selection of sites and species that may not represent the entire population.

Limitations

The study may have confounding factors due to overrepresentation of certain species in high prevalence sites.

Participant Demographics

The study included 2,121 small mammals, primarily rodents, from various sites in northern and central California.

Statistical Information

P-Value

0.05

Confidence Interval

95% CI 13.6–16.9

Statistical Significance

p<0.05

Digital Object Identifier (DOI)

10.3201/eid1407.071599

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