Emergence of tick-borne granulocytic anaplasmosis associated with habitat type and forest change in northern California

Janet E Foley, Nathan C. Nieto, Patrick Foley

Research output: Contribution to journalArticle

14 Citations (Scopus)

Abstract

An important ecosystem service of intact forests is protection from some emerging infectious diseases.Tick-transmitted disease granulocytic anaplasmosis increasingly occupies second-growth forest. We hypothesized that areas of second growth would have increases in tick and rodent abundance, facilitating emergence of anaplasmosis. We predicted Anaplasma phagocytophilum presence as a function of biocomplexity and forest structure, including vegetation, ticks, and rodents in four sites in California. Significant risk factors for exposure included host species (woodrats with 13% seroprevalence, odds ratio [OR] = 8.3 and chipmunks with 27% seroprevalence, OR = 20.7), and park location (northern parks, OR 25.5-27.7). Exposure to A. phagocytophilum was more likely among chipmunks in redwood sites at one park, but with woodrats and oaks at another. Overall, transects on which small mammals showed greatest A. phagocytophilum exposure had high biodiversity in ticks, rodents, and vegetation, as well as intermediate-sized trees with a high mean and variance in diameter at breast height, findings which suggest that a dilution effect, where increased biodiversity reduces disease risk, does not necessarily apply in this system. Thus, enzootic and potentially emerging anaplasmosis were linked to high biodiversity and mature second-growth forest.

Original languageEnglish (US)
Pages (from-to)1132-1140
Number of pages9
JournalAmerican Journal of Tropical Medicine and Hygiene
Volume81
Issue number6
DOIs
StatePublished - Dec 2009

Fingerprint

Anaplasmosis
Anaplasma phagocytophilum
Ticks
Ecosystem
Biodiversity
Rodentia
Sciuridae
Odds Ratio
Seroepidemiologic Studies
Sequoia
Growth
Emerging Communicable Diseases
Mammals
Breast
Forests

ASJC Scopus subject areas

  • Parasitology
  • Infectious Diseases
  • Virology
  • Medicine(all)

Cite this

Emergence of tick-borne granulocytic anaplasmosis associated with habitat type and forest change in northern California. / Foley, Janet E; Nieto, Nathan C.; Foley, Patrick.

In: American Journal of Tropical Medicine and Hygiene, Vol. 81, No. 6, 12.2009, p. 1132-1140.

Research output: Contribution to journalArticle

@article{2d5dc166c58a49428223870a51f80d91,
title = "Emergence of tick-borne granulocytic anaplasmosis associated with habitat type and forest change in northern California",
abstract = "An important ecosystem service of intact forests is protection from some emerging infectious diseases.Tick-transmitted disease granulocytic anaplasmosis increasingly occupies second-growth forest. We hypothesized that areas of second growth would have increases in tick and rodent abundance, facilitating emergence of anaplasmosis. We predicted Anaplasma phagocytophilum presence as a function of biocomplexity and forest structure, including vegetation, ticks, and rodents in four sites in California. Significant risk factors for exposure included host species (woodrats with 13{\%} seroprevalence, odds ratio [OR] = 8.3 and chipmunks with 27{\%} seroprevalence, OR = 20.7), and park location (northern parks, OR 25.5-27.7). Exposure to A. phagocytophilum was more likely among chipmunks in redwood sites at one park, but with woodrats and oaks at another. Overall, transects on which small mammals showed greatest A. phagocytophilum exposure had high biodiversity in ticks, rodents, and vegetation, as well as intermediate-sized trees with a high mean and variance in diameter at breast height, findings which suggest that a dilution effect, where increased biodiversity reduces disease risk, does not necessarily apply in this system. Thus, enzootic and potentially emerging anaplasmosis were linked to high biodiversity and mature second-growth forest.",
author = "Foley, {Janet E} and Nieto, {Nathan C.} and Patrick Foley",
year = "2009",
month = "12",
doi = "10.4269/ajtmh.2009.09-0372",
language = "English (US)",
volume = "81",
pages = "1132--1140",
journal = "American Journal of Tropical Medicine and Hygiene",
issn = "0002-9637",
publisher = "American Society of Tropical Medicine and Hygiene",
number = "6",

}

TY - JOUR

T1 - Emergence of tick-borne granulocytic anaplasmosis associated with habitat type and forest change in northern California

AU - Foley, Janet E

AU - Nieto, Nathan C.

AU - Foley, Patrick

PY - 2009/12

Y1 - 2009/12

N2 - An important ecosystem service of intact forests is protection from some emerging infectious diseases.Tick-transmitted disease granulocytic anaplasmosis increasingly occupies second-growth forest. We hypothesized that areas of second growth would have increases in tick and rodent abundance, facilitating emergence of anaplasmosis. We predicted Anaplasma phagocytophilum presence as a function of biocomplexity and forest structure, including vegetation, ticks, and rodents in four sites in California. Significant risk factors for exposure included host species (woodrats with 13% seroprevalence, odds ratio [OR] = 8.3 and chipmunks with 27% seroprevalence, OR = 20.7), and park location (northern parks, OR 25.5-27.7). Exposure to A. phagocytophilum was more likely among chipmunks in redwood sites at one park, but with woodrats and oaks at another. Overall, transects on which small mammals showed greatest A. phagocytophilum exposure had high biodiversity in ticks, rodents, and vegetation, as well as intermediate-sized trees with a high mean and variance in diameter at breast height, findings which suggest that a dilution effect, where increased biodiversity reduces disease risk, does not necessarily apply in this system. Thus, enzootic and potentially emerging anaplasmosis were linked to high biodiversity and mature second-growth forest.

AB - An important ecosystem service of intact forests is protection from some emerging infectious diseases.Tick-transmitted disease granulocytic anaplasmosis increasingly occupies second-growth forest. We hypothesized that areas of second growth would have increases in tick and rodent abundance, facilitating emergence of anaplasmosis. We predicted Anaplasma phagocytophilum presence as a function of biocomplexity and forest structure, including vegetation, ticks, and rodents in four sites in California. Significant risk factors for exposure included host species (woodrats with 13% seroprevalence, odds ratio [OR] = 8.3 and chipmunks with 27% seroprevalence, OR = 20.7), and park location (northern parks, OR 25.5-27.7). Exposure to A. phagocytophilum was more likely among chipmunks in redwood sites at one park, but with woodrats and oaks at another. Overall, transects on which small mammals showed greatest A. phagocytophilum exposure had high biodiversity in ticks, rodents, and vegetation, as well as intermediate-sized trees with a high mean and variance in diameter at breast height, findings which suggest that a dilution effect, where increased biodiversity reduces disease risk, does not necessarily apply in this system. Thus, enzootic and potentially emerging anaplasmosis were linked to high biodiversity and mature second-growth forest.

UR - http://www.scopus.com/inward/record.url?scp=73949143178&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=73949143178&partnerID=8YFLogxK

U2 - 10.4269/ajtmh.2009.09-0372

DO - 10.4269/ajtmh.2009.09-0372

M3 - Article

C2 - 19996448

AN - SCOPUS:73949143178

VL - 81

SP - 1132

EP - 1140

JO - American Journal of Tropical Medicine and Hygiene

JF - American Journal of Tropical Medicine and Hygiene

SN - 0002-9637

IS - 6

ER -