Table 4.
Notable information on human encounters with native tick species in the United States (US) not included in the quantitative data compilation.
| Reference | Geographical areaa | Time period | Notes on human tick encounters in the US (synonyms for species used in the publication)b |
|---|---|---|---|
| Kalm (1772) | Northeast US | 1749 | Report of human infestation by ticks (wood lice), most likely belonging to Amblyomma americanum as collected specimens later were classified as Acarus americanus by Linneus. |
| Packard (1869) | PA | Not stated | Report of a human bite by Amblyomma americanum (=Ixodes unipunctata), but the species identification is uncertain as it was made from a drawing of the tick. |
| Curtice (1892) | US | Up to 1892 | Mention in general terms of the following species infesting humans: Amblyomma americanum (=Amblyomma unipunctata), Dermacentor occidentalis, Dermacentor variabilis (=Dermacentor americanus), and Ixodes scapularis. |
| Neumann (1901) | US | Up to 1901 | Mention in general terms of the following species as present in the US and as associated with humans: Amblyomma americanum, Argas miniatus, Dermacentor parumapertus, Dermacentor variabilis (=Dermacentor electus), and Ornithodoros turicata. |
| Cary (1907) | US | Up to 1907 | Mention in general terms of the following species infesting humans: Amblyomma americanum, Dermacentor occidentalis (=Dermacentor reticulatus), Dermacentor variabilis (=Dermacentor electus), Ixodes cookei (=Ixodes hexagonus), and Ixodes scapularis (=Ixodes ricinus). |
| Hunter and Hooker (1907) | US | Up to 1907 | Mention in general terms of the following species infesting humans: Amblyomma americanum, Amblyomma maculatum, Dermacentor occidentalis, and Dermacentor parumapertus. Also includes quantitative data for Otobius megnini (=Ornithodoros megnini) and Rhipicephalus annulatus (=Margaropus annulatus); see Table 3. |
| Banks (1905, 1908) | US | Up to 1908 | Mention in general terms of the following species infesting humans: Amblyomma americanum, Amblyomma maculatum, Dermacentor andersoni (=Dermacentor venustus), Dermacentor parumapertus, Dermacentor variabilis, Ixodes cookei, Ixodes scapularis, Ornithodoros coriaceus, Ornithodoros turicata, and Otobius megnini (=Ornithodoros megnini). |
| Hunter and Bishopp (1911b) | US | Up to 1911 | Mention in general terms of the following species infesting humans: Amblyomma americanum, Amblyomma maculatum, Dermacentor andersoni (=Dermacentor venustus), Dermacentor occidentalis, Dermacentor variabilis, and Otobius megnini (=Ornithodoros megnini). |
| Nuttall et al. (1911) | US | Up to 1911 | Mention in general terms of the following species infesting humans: Ixodes scapularis (=Ixodes ricinus var. scapularis), Ornithodoros turicata, and Otobius megnini (=Ornithodoros megnini). |
| Mohler (1914) | US | Up to 1914 | Mention in general terms of the following species infesting humans: Amblyomma americanum, Dermacentor albipictus, Dermacentor variabilis, Ixodes cookei (=Ixodes hexagonus), and Ixodes scapularis (=Ixodes ricinus). |
| Cooley (1915) | MT | Up to 1915 | Mention in general terms of Dermacentor andersoni (=Dermacentor venustus) infesting humans. |
| Parker and Wells (1917) | MT | Up to 1917 | Mention in general terms of the following species infesting humans: Dermacentor andersoni (=Dermacentor venustus) and Dermacentor variabilis. |
| Bruce (1934) | TX | 1930 | Report of human infestation by Ornithodoros turicata after visiting a cave. |
| Bishopp and Hixson (1936) | US | Up to 1936 | Mention in general terms of Amblyomma maculatum infesting humans. |
| Chamberlin (1937) | OR | Up to 1937 | Mention in general terms of the following species infesting humans: Dermacentor andersoni, Dermacentor occidentalis, Ixodes angustus, and Ixodes pacificus (=Ixodes californicus). |
| Cooley (1938) | US | Up to 1938 | Mention in general terms of the following species infesting humans: Dermacentor andersoni, Dermacentor occidentalis, Dermacentor parumapertus, and Dermacentor variabilis. |
| Brunet (1939) | US | 1932–1934 | Report of two cases of human tick infestation, presumably with Dermacentor andersoni. |
| Bishopp (1941) | US | Up to 1941 | Mention in general terms of Argas miniatus biting humans. |
| Davis et al. (1941) | CA | 1940 | Report of human bites by numerous ticks at a sandstone cliff with small caves, where Ornithodoros parkeri ticks subsequently were collected. |
| Travis (1941) | FL | 1936–1937 | Mention in general terms of the following species infesting humans: Amblyomma americanum, Amblyomma maculatum, and Ixodes scapularis (Ixodes ricinus scapularis). |
| Parker et al. (1943) | OK, SC, TX | 1941–1942 | Report of ticks infesting humans developing Rocky Mountain spotted fever, with Amblyomma americanum collected around case premises. |
| Woodland et al. (1943) | TX | 1942 | Mention in general terms of Amblyomma americanum infesting humans. |
| Archer (1944) | TN | Up to 1944 | Mention in general terms of the following species infesting humans: Amblyomma americanum and Dermacentor variabilis. |
| Cooley and Kohls (1944a) | US | Up to 1944 | Mention in general terms of the following species infesting humans or found in homes or cabins of tick bite victims: Ornithodoros coriaceus, Ornithodoros hermsi, and Ornithodoros turicata. Also includes quantitative data for Ornithodoros parkeri, Ornithodoros stageri, and Otobius megnini; see Table 3. |
| Brennan (1945) | TX | 1943–1944 | Mention in general terms of the following species infesting humans: Amblyomma americanum and Ixodes scapularis. |
| MacCreary (1945) | DE | 1939–1944 | Mention in general terms of Dermacentor variabilis infesting humans. Also includes quantitative data for Amblyomma americanum; see Table 3. |
| Cooley (1946a) | US | Up to 1946 | Mention in general terms of Rhipicephalus sanguineus sensu lato (s.l.) infesting humans. |
| Bequaert (1947) | NH | 1947 | Mention in general terms of Dermacentor variabilis infesting humans. |
| Collins et al. (1949) | NY | Up to 1949 | Mention in general terms of the following species infesting humans: Dermacentor variabilis, Ixodes dentatus, and Ixodes scapularis. |
| Holdenried et al. (1951) | CA | 1940–1945 | Mention in general terms of the following species infesting humans (field workers): Dermacentor occidentalis (adults and immatures) and Ornithodoros turicata (several larvae after probing a ground squirrel burrow by hand). Also includes quantitative data for Ixodes pacificus; see Table 3. |
| Tibbetts (1953) | NC | 1952 | Mention in general terms of the following species infesting humans: Amblyomma americanum and Ixodes scapularis. |
| Coffey (1954) | UT | Up to 1954 | Mention in general terms of Dermacentor andersoni infesting humans. |
| Beck (1955b) | UT | Up to 1955 | Mention in general terms of Dermacentor andersoni infesting humans. |
| White (1955) | MS | 1947–1949 | Mention in general terms of the following species infesting humans: Amblyomma americanum (adults, nymphs, and larvae), Amblyomma maculatum (adults), Dermacentor variabilis (adults), and Ixodes scapularis (adults). |
| Kohls et al. (1957) | US | Up to 1957 | Mention in general terms of the following species infesting humans or found in homes of tick bite victims: Ornithodoros capensis, Ornithodoros concanensis, Ornithodoros coriaceus, Ornithodoros kelleyi, Ornithodoros parkeri, Ornithodoros turicata, and Otobius megnini. |
| Kohls (1958) | TX | Up to 1958 | Mention in general terms of Amblyomma tenellum (=Amblyomma imitator) infesting humans. |
| Clifford et al. (1961) | Eastern US | Up to 1961 | Mention in general terms of the following species infesting humans: Amblyomma americanum (AL, LA, VA) and Ixodes muris (NY). |
| Johnson (1962) | CO | 1961 | Mention in general terms of Dermacentor andersoni infesting humans. |
| Clark (1964) | GA | 1961–1962 | Mention in general terms of the following species infesting humans: Amblyomma americanum and Dermacentor variabilis. |
| Allred (1968) | ID | 1966–1967 | Mention in general terms of Dermacentor andersoni (adults) infesting humans. |
| Snetsinger (1968) | PA | Up to 1968 | Mention in general terms of the following species infesting humans: Amblyomma americanum, Dermacentor albipictus, Dermacentor variabilis, Ixodes angustus, Ixodes cookei, Ixodes marxi, and Rhipicephalus sanguineus s. l. Also includes quantitative data for Amblyomma maculatum; see Table 3. |
| Duckworth et al. (1985) | VA | 1982–1983 | Mention in general terms of Amblyomma americanum (larvae) infesting humans. |
| Goddard (1990) | AR | 1988 | Report of numerous tick bites during military training, most likely predominantly by Amblyomma americanum. |
| Webb et al. (1990) | CA | Up to 1990 | Mention in general terms of Ixodes pacificus infesting humans. |
| Robbins and Keirans (1992) | North America | Up to 1992 | Mention in general terms of the following species infesting humans in North America: Ixodes angustus, Ixodes soricis, and Ixodes woodi. |
| Durden and Kollars (1992) | TN | Up to 1992 | Mention in general terms of the following species infesting humans: Amblyomma americanum and Dermacentor variabilis. |
| Durden and Keirans (1996) | US | Up to 1996 | Mention in general terms of the following species infesting humans in North America: Ixodes angustus, Ixodes cookei, Ixodes dentatus, Ixodes pacificus, Ixodes scapularis, Ixodes spinipalpis (=Ixodes neotomae), Ixodes texanus, and Ixodes woodi. |
| Lavender and Oliver (1996) | GA | 1984–1985 | Mention in general terms of Ixodes scapularis infesting humans. |
| Williams et al. (1999) | SC | Up to 1999 | Mention in general terms of the following species infesting humans: Amblyomma americanum, Amblyomma maculatum, Dermacentor variabilis, Ixodes brunneus, and Ixodes scapularis. |
| Johnson et al. (2004) | Ri | 1991–200 | Report of human infestation by Ixodes scapularis in Rhode Island. Data were collected from 1991 to 2000 via a passive tick collection initiative. The paper includes 1,033 submitted I. scapularis nymphs but it is not clearly stated if they all were collected from humans (rather than pets or other sources). |
| Fisher et al. (2006) | KY | Not stated | Report of multiple larval bites by Amblyomma ticks, presumably Amblyomma americanum. |
| Nelder et al. (2009) | SC | 2004–2007 | Mention in general terms of the following species infesting humans in zoos: Amblyomma americanum and Dermacentor variabilis. |
| Lubelczyk et al. (2010) | ME, VT | 2008 | Report of tick bites in cabins subsequently found to be infested with Ixodes cookei and Ixodes marxi. |
| Vaughn and Meshnick (2011) | NC | 2008 | Report of 74 tick bites in a tick bite prevention intervention study in North Carolina, but without specifying the tick species. Based on the study location, the majority of the biting ticks likely were Amblyomma americanum. |
| Vaughn et al. (2014) / Wallace et al. (2016) | NC | 2011–2012 | Report of 1,045 human tick bites in a tick bite prevention intervention study, with Amblyomma americanum accounting for >90% of a subset of 867 ticks identified to species, and with additional recorded species including Amblyomma maculatum, Dermacentor variabilis, and Ixodes scapularis. |
| Rossi et al. (2015) | Eastern US | 2006–2012 | Report of 11,282 ticks (including Amblyomma americanum, Dermacentor variabilis, and Ixodes scapularis) collected from patients at Military Treatment Facilities in the eastern US, but without a breakdown in the paper allowing for calculation of numbers by tick species. |
| Xu et al. (2016) | US | 2006–2012 | Report of 3,551 ticks (3,127 Ixodes scapularis, 231 Dermacentor variabilis, 159 Amblyomma americanum, 26 Ixodes pacificus, 5 Rhipicephalus sanguineus s.l., 1 Dermacentor occidentalis, and 1 Haemaphysalis leporispalustris) collected from humans and domestic animals via a passive tick collection initiative but without a breakdown of numbers by tick species collected specifically from humans, with the exception that quantitative data were presented for a subset of 1,962 Ixodes scapularis collected from humans in Massachusetts (see Table 3). |
| Hinckley et al. (2016) | CT, MD, NY | 2011–2013 | Report of ticks found crawling on or attached to humans in a tick control intervention study in Connecticut, Maryland, and New York, but without providing information either for number of ticks or tick species. Based on the study locations, it appears likely the majority of the biting ticks were Ixodes scapularis, Dermacentor variabilis, and Amblyomma americanum. |
| Egizi et al. (2017) | NJ | 2006–2015 | Report of human infestation by thousands of Amblyomma americanum and Ixodes scapularis via a passive tick collection initiative in Monmouth County, New Jersey from 2006 to 2015, presented only graphically without specifying exact numbers. |
| Mead et al. (2018) | CT | 2013 | Report of ticks found crawling on or attached to humans in a tick control intervention study in Connecticut, but without providing information either for number of ticks or tick species. Based on the study locations, it appears likely the majority of the biting ticks were Ixodes scapularis and Dermacentor variabilis. |
| Nieto et al. (2018) | US | 2016–2017 | Report of 11,486 ticks collected from humans and submitted via a nationwide passive tick collection initiative, but without a breakdown of numbers by tick species collected specifically from humans. Quantitative data for subsets of ticks, by species, recorded from humans were later presented by Porter et al. (2019) for the northeastern US and Salkeld et al. (2019) for California; see Table 3. |
| Nigrovic et al. (2019) | DE, MA, PA, RI, WI | 2015–2018 | Report of 167 tick bites in children diagnosed with Lyme disease in Delaware, Massachusetts, Pennsylvania, Rhode Island, and Wisconsin, but without specifying the tick species. Based on the study locations, it appears likely the majority of the biting ticks were Ixodes scapularis and Dermacentor variabilis. |
| Elias et al. (2020) | ME | 1990–2013 | Report of Ixodes scapularis collected from humans via a passive surveillance initiative in Maine from 1990 to 2013. Data from 1990 to 2006 were previously included in Rand et al. (2007) and the paper does not include information specifically for the subsequent period from 2007 to 2013. |
| Mitchell et al. (2020b) | MA, RI | 2016–2018 | Report of 226 tick bites in a tick bite prevention intervention study in Massachusetts and Rhode Island, but without specifying the tick species. Based on the study locations, it appears likely the majority of the biting ticks were Ixodes scapularis and Dermacentor variabilis. |
| Bechtel et al. (2021) | NV | 2017–2018 | Report of tick-borne relapsing fever in scientists following exposure to argasid ticks, most likely Ornithodoros turicata, associated with tortoise burrows. |
| Hinckley et al. (2021) | CT | 2012–2016 | Report of ticks found crawling on or attached to humans in a tick control intervention study in Connecticut, but without providing information for either number of ticks or tick species. Based on the study location, it appears likely the majority of the ticks were Ixodes scapularis and Dermacentor variabilis. |
| Lyons et al. (2021) | IL | 2018 | Report of 261 Dermacentor variabilis (all adults), 150 Amblyomma americanum (78 adults and 72 nymphs), 21 Ixodes scapularis (16 adults and 5 nymphs), and 4 Amblyomma maculatum (all adults) collected from humans and pets, but without a breakdown for the number of ticks recorded specifically from humans. |
| Rounsville et al. (2021) | ME | 2019 | Report of 2,016 Ixodes scapularis (1413 females, 30 males, 553 nymphs, and 20 larvae) submitted via a passive tick collection initiative in Maine, but without a clear statement of the proportion of ticks recorded from humans versus pets or other animals. |
| Dowling et al. (2022) | AR | 2017–2018 | Report of 9,002 ticks collected from humans, pets and livestock and submitted via a passive tick collection initiative in Arkansas. This included 6,854 Amblyomma americanum, 1,357 Dermacentor variabilis, 282 Ixodes scapularis, 257 Amblyomma maculatum, 242 Rhipicephalus sanguineus s.l., 8 Dermacentor albipictus, 1 Haemaphysalis leporispalustris, and 1 Ixodes cookei, but it is not clear from the paper which proportion of these ticks were recorded from humans versus pets or livestock. |
| Keesing et al. (2022) | NY | 2017–2020 | Report of 1,664 human encounters with ticks in a tick control intervention study in New York, but without specifying the tick species. Based on the study location, it appears likely the majority of the ticks were Ixodes scapularis and Dermacentor variabilis. |
| Pasternak and Palli (2022) | KY | 2019–2020 | Report of 336 Ixodes scapularis (330 adults, 5 nymphs, and 1 larva) collected from humans and pets, but without a breakdown for the number of ticks recorded specifically from humans. |
a
Geographical area listed by state(s), or a larger geographical area if state level data were not provided. State level records may include tick exposures resulting from travel within the US.
b
Based on taxonomic nomenclature presented by Guglielmone et al. (2010, 2014, 2020), Nava et al. (2014a, 2014b, 2015, 2017), and Guglielmone and Robbins (2018). Some other authors (see Mans et al., 2019) place four of the Ornithodoros species (Or. capensis, Or. concanensis, Or. kelleyi, and Or. stageri) included in this table in the genus Carios.