CORD-19-Sentences  

CORD-19:09767b040fe1e66abe5c3d292674255534c98af3 JSONTXT 7 Projects

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Id Subject Object Predicate Lexical cue
TextSentencer_T1 0-78 Sentence denotes Health of Antarctic birds: a review of their parasites, pathogens and diseases
TextSentencer_T2 80-88 Sentence denotes Abstract
TextSentencer_T3 89-158 Sentence denotes Antarctic birds are not beyond the effects of parasites or pathogens.
TextSentencer_T4 159-294 Sentence denotes However, potential ecological consequences of wide-spread infections for bird populations in Antarctica have received little attention.
TextSentencer_T5 295-412 Sentence denotes In this paper, we review the information published about disease and parasites, and their effects on Antarctic birds.
TextSentencer_T6 413-637 Sentence denotes The information on host species, parasites and pathogens, and geographic regions is incomplete and data on ecological effects on the populations, including how birds respond to pathogens and parasites, are almost inexistent.
TextSentencer_T7 638-828 Sentence denotes We conclude that more research is needed to establish general patterns of spatial and temporal variation in pathogens and parasites, and to determine how such patterns could influence hosts.
TextSentencer_T8 829-951 Sentence denotes This information is crucial to limit the spread of outbreaks and may aid in the decision-making process should they occur.
TextSentencer_T9 953-1050 Sentence denotes Disease is one of the main agents of morbidity and mortality in living organisms (Haldane 1949) .
TextSentencer_T10 1051-1101 Sentence denotes A single outbreak can decimate animal populations.
TextSentencer_T11 1102-1216 Sentence denotes Some examples include the death of 18,000 seals in Northern Europe from the Phocine Distemper Virus (Jensen et al.
TextSentencer_T12 1217-1523 Sentence denotes 2002) , the loss of 40,000 Mallards due to the appearance of new diseases (Friend 2006) , a decrease in the population of North American House Finch due to Mycoplasma conjunctivitis (Hochachka and Dhondt 2000) and the decline of several species of frogs in Australia from a virus infection (Laurance et al.
TextSentencer_T13 1524-1545 Sentence denotes 1996) , among others.
TextSentencer_T14 1546-1750 Sentence denotes However, disease (including both effects of microbes and parasites) has only recently been recognized as an active player in ecosystems through its effects on host populations (Grenfell and Dobson 1995) .
TextSentencer_T15 1751-1827 Sentence denotes Infectious disease outbreaks can lead to catastrophic population reductions.
TextSentencer_T16 1828-1925 Sentence denotes However, pathogens and parasites can also cause variations in metabolic rate (e.g., Møller et al.
TextSentencer_T17 1926-2182 Sentence denotes 1994) , and influence life history traits, such as the phenology of reproduction, clutch size, and brood size (see revision in Møller 1997) , the expression of secondary sexual characters (Hillgarth and Wingfield 1997) as well as social status (Rau 1983) .
TextSentencer_T18 2183-2323 Sentence denotes Despite their geographical isolation, habitats such as the Antarctic ecosystems are not beyond the risk posed by pathogens and/or parasites.
TextSentencer_T19 2324-2400 Sentence denotes So far, only a few events of mass mortality have been reported (Kerry et al.
TextSentencer_T20 2401-2600 Sentence denotes 1999) and no major outbreaks of infectious diseases have been described in Antarctica (Weimerskirch 2004) , although some were reported from remote islands in the Southern Ocean (Weimerskirch 2004) .
TextSentencer_T21 2601-2666 Sentence denotes However, increased warming across the continent (see Steig et al.
TextSentencer_T22 2667-2747 Sentence denotes 2009 ) may make the survival of pathogens and large-scale outbreaks more likely.
TextSentencer_T23 2748-2964 Sentence denotes During the ''Workshop on diseases in Antarctic Wildlife'' held in Hobart in 1998 a number of recommendations were made for their monitoring and prevention of Antarctic Treaty Consultative Meeting (ACTM) (Kerry et al.
TextSentencer_T24 2965-2972 Sentence denotes 1999 ).
TextSentencer_T25 2973-3181 Sentence denotes One of the recommendations was to establish that ''a structured research program is required to provide information about what is normal and what is aberrant in the health of Antarctic species'' (Kerry et al.
TextSentencer_T26 3182-3189 Sentence denotes 1999) .
TextSentencer_T27 3190-3238 Sentence denotes However, to date this has not yet been achieved.
TextSentencer_T28 3239-3350 Sentence denotes What is required is an in-depth review on the epidemiology of diseases and their status in any Antarctic birds.
TextSentencer_T29 3351-3443 Sentence denotes The only review currently available focuses solely on penguins (see Clarke and Kerry 2000) .
TextSentencer_T30 3444-3628 Sentence denotes This information is important in terms of ecosystem health, as any variation in the prevalence of a disease in species may be a sign of ''ecosystem distress syndrome'' (Rapport 2007) .
TextSentencer_T31 3629-3879 Sentence denotes Global change is one of the main factors affecting ecosystem health through the relationship between climate change and global human travel, and the increase of distribution ranges, abundance and/or virulence of parasites and pathogens (Daszak et al.
TextSentencer_T32 3880-3916 Sentence denotes 2000; Sutherst 2001 , Harvell et al.
TextSentencer_T33 3917-3936 Sentence denotes 2002 Epstein et al.
TextSentencer_T34 3937-3944 Sentence denotes 2003) .
TextSentencer_T35 3945-4054 Sentence denotes In Antarctica, especially the Antarctic Peninsula and West Antarctica, temperatures have risen (Turner et al.
TextSentencer_T36 4055-4084 Sentence denotes 2004; IPCC 2007; Steig et al.
TextSentencer_T37 4085-4092 Sentence denotes 2009 ).
TextSentencer_T38 4093-4242 Sentence denotes Furthermore, human activities, such as research stations, as well as increasing tourism activities can facilitate the spread of disease (Curry et al.
TextSentencer_T39 4243-4250 Sentence denotes 2002) .
TextSentencer_T40 4251-4411 Sentence denotes Research activities tend to concentrate on relatively small areas or specific locations while tourists visit a great number of colonies in a short span of time.
TextSentencer_T41 4412-4621 Sentence denotes It is worth mentioning that tour companies that are members of the International Antarctic Tour Operator (IAATO) have a boot-cleaning policy which may reduce such risk, as long as it is carried out thoroughly.
TextSentencer_T42 4622-4734 Sentence denotes Companies that are not IAATO members and private vessels are more likely to contribute to the spread of disease.
TextSentencer_T43 4735-4792 Sentence denotes Finally, disease can also be spread by migratory species.
TextSentencer_T44 4793-5082 Sentence denotes These species are thought to be responsible for transmission of several viruses, such as influenza or New Castle disease, bacteria, such as Campylobacter jejuni, Pasteurella multocida, Clostridium botulinum and Mycobacterium avium, and protozoa, such as Cryptosporidium sp (Hubalek 2004) .
TextSentencer_T45 5083-5145 Sentence denotes These agents are a recognized risk in Antarctica (Kerry et al.
TextSentencer_T46 5146-5153 Sentence denotes 1999) .
TextSentencer_T47 5154-5381 Sentence denotes The aim of this paper is to compile published information on the presence and the effects of disease, pathogens and parasites in Antarctic birds to provide a baseline for the evaluation of the health of the Antarctic ecosystem.
TextSentencer_T48 5382-5518 Sentence denotes The information was taken from papers referenced in the Zoological Record and PubMed database and from indepth bibliographical research.
TextSentencer_T49 5519-5739 Sentence denotes Antarctic birds were those non-passerines included in the book, ''A Complete Guide to Antarctic Wildlife'' (Shirihai 2002) breeding and distributed in Antarctica and sub-Antarctic islands south of 45°S (see Frenot et al.
TextSentencer_T50 5740-5797 Sentence denotes 2005 for a similar consideration of Antarctic territory).
TextSentencer_T51 5798-5853 Sentence denotes We examined information for 46 bird species (Table 1) .
TextSentencer_T52 5854-6019 Sentence denotes Data on whether microorganisms (virus and bacteria) were detected by means of serology or by isolation were given as well as information about geographical location.
TextSentencer_T53 6020-6195 Sentence denotes We reviewed 101 published papers dealing with issues related to parasites, pathogens or diseases (Table 1) , and found information on 38 out of 46 (82%) bird species searched.
TextSentencer_T54 6196-6266 Sentence denotes The number of publications per species was highly variable (Table 1) .
TextSentencer_T55 6267-6539 Sentence denotes For example, Adelie (Pygoscelis adeliae), the Gentoo (Pygoscelis papua), and the Chinstrap (Pygoscelis antarctica), as well as kelp gulls (Larus dominicanus), were mentioned in more than 15 publications compared to only three dealing with Antarctic terns (Sterna vittata).
TextSentencer_T56 6540-6794 Sentence denotes With respect to disease agents (or antibodies) reportedly in Antarctic birds, bacteria were detected in 15 species (33%), viruses in 9 (20%), protozoa in 14 (30%), gastrointestinal parasites in 20 (44%), and ectoparasites in 37 species (80%) ( Table 1 ).
TextSentencer_T57 6795-7057 Sentence denotes The species with the highest number of parasites or pathogens described are the three pygoscelid penguins, the giant petrels (Macronectes giganteus), sub-Antarctic skuas (Catharacta skua lonnbergi), sheathbills (Chionis alba), and kelp gulls (Larus dominicanus).
TextSentencer_T58 7058-7191 Sentence denotes However, this difference is probably more a reflection of the differences in research effort rather than based on biological reasons.
TextSentencer_T59 7192-7377 Sentence denotes The distribution of parasites and pathogens in Antarctic birds shows that seven viruses are likely to be present, of which only paramyxovirus and poxvirus have been isolated (Table 1) .
TextSentencer_T60 7378-7596 Sentence denotes The viruses responsible for infectious bursal disease, Newcastle disease and influenza have only been reported from serological studies and have never been isolated in Antarctica Austin and Webster 1993; Gardner et al.
TextSentencer_T61 7597-7624 Sentence denotes 1997; Gauthier-Clerc et al.
TextSentencer_T62 7625-7648 Sentence denotes 2002; Baumeister et al.
TextSentencer_T63 7649-7672 Sentence denotes 2004; Wallensten et al.
TextSentencer_T64 7673-7692 Sentence denotes 2006; Miller et al.
TextSentencer_T65 7693-7700 Sentence denotes 2008) .
TextSentencer_T66 7701-7869 Sentence denotes Moreover in the studies where isolation or direct detection (i.e., PCR methods) was carried out, results have been negative (Morgan and Westbury 1988; Wallensten et al.
TextSentencer_T67 7870-7877 Sentence denotes 2006) .
TextSentencer_T68 7878-8167 Sentence denotes Thus, if the presence of viruses is implied and solely determined by serological techniques, caution, needs to be applied when interpreting the results and further studies applying direct detection or isolation should be carried out to confirm or reject the presence of a certain organism.
TextSentencer_T69 8168-8289 Sentence denotes Of the 42 bacteria reported in Antarctic birds, 37 were isolated, and seven were detected only by serological techniques.
TextSentencer_T70 8290-8415 Sentence denotes The main bacteria detected were Campylobacter lari, the common bacteria causing enteritis in birds and Austrogoniodes mawsoni
TextSentencer_T71 8416-8437 Sentence denotes Tetrabothrius wrighti
TextSentencer_T72 8438-8460 Sentence denotes Austrogoniodes mawsoni
TextSentencer_T73 8461-8479 Sentence denotes Parorchites zederi
TextSentencer_T74 8480-8496 Sentence denotes Pygoscelis papua
TextSentencer_T75 8498-8518 Sentence denotes Docophoroides brevis
TextSentencer_T76 8519-8539 Sentence denotes Naubates fuliginosus
TextSentencer_T77 8540-8560 Sentence denotes Naubates fuliginosus
TextSentencer_T78 8561-8580 Sentence denotes Pseudonirmus gurlti
TextSentencer_T79 8581-8599 Sentence denotes Trabeculus hexacon
TextSentencer_T80 8600-8620 Sentence denotes Docophoroides brevis
TextSentencer_T81 8621-8643 Sentence denotes Harrisoniella hopkinsi
TextSentencer_T82 8644-8666 Sentence denotes Harrisoniella hopkinsi
TextSentencer_T83 8667-8685 Sentence denotes Paraclisis hyalina
TextSentencer_T84 8686-8704 Sentence denotes Paraclisis hyalina
TextSentencer_T85 8705-8724 Sentence denotes Naubates pterodromi
TextSentencer_T86 8725-8745 Sentence denotes Austromenopon affine
TextSentencer_T87 8746-8767 Sentence denotes Perineus concinnoides
TextSentencer_T88 8768-8790 Sentence denotes Episbates pederiformis
TextSentencer_T89 8791-8839 Sentence denotes Thalassarche melanophrys Halipeurus procellariae
TextSentencer_T90 8840-8863 Sentence denotes Halipeurus procellariae
TextSentencer_T91 8864-8883 Sentence denotes Naubates pterodromi
TextSentencer_T92 8884-8906 Sentence denotes Naubates heteroproctus
TextSentencer_T93 8907-8929 Sentence denotes Naubates heteroproctus
TextSentencer_T94 8930-8975 Sentence denotes Saemundssonia sp 1 (14) Trabeculus schillingi
TextSentencer_T95 8976-8997 Sentence denotes Trabeculus schillingi
TextSentencer_T96 8998-9058 Sentence denotes Pterodroma mollis Ancistrona sp 1 (98) Longimenopon galeatum
TextSentencer_T97 9059-9080 Sentence denotes Longimenopon galeatum
TextSentencer_T98 9081-9096 Sentence denotes Naubates prioni
TextSentencer_T99 9097-9112 Sentence denotes Naubates prioni
TextSentencer_T100 9113-9131 Sentence denotes Naubates clypeatus
TextSentencer_T101 9132-9151 Sentence denotes Halipeurus diversus
TextSentencer_T102 9152-9169 Sentence denotes Halipeurus turtur
TextSentencer_T103 9170-9209 Sentence denotes Trabeculus sp 1 (14) Pachyptilla turtur
TextSentencer_T104 9210-9232 Sentence denotes Naubates prioni 1 (98)
TextSentencer_T105 9233-9252 Sentence denotes Ixodes kerguelensis
TextSentencer_T106 9253-9273 Sentence denotes Zachvatkinia robusta
TextSentencer_T107 9274-9294 Sentence denotes Docophoroides brevis
TextSentencer_T108 9295-9315 Sentence denotes Naubates fuliginosus
TextSentencer_T109 9316-9336 Sentence denotes Naubates fuliginosus
TextSentencer_T110 9337-9356 Sentence denotes Pseudonirmus gurlti
TextSentencer_T111 9357-9375 Sentence denotes Trabeculus hexacon
TextSentencer_T112 9376-9394 Sentence denotes Trabeculus hexacon
TextSentencer_T113 9395-9414 Sentence denotes Procellaria cinerea
TextSentencer_T114 9415-9435 Sentence denotes Naubates fuliginosus
TextSentencer_T115 9436-9454 Sentence denotes Trabeculus hexacon
TextSentencer_T116 9455-9478 Sentence denotes Halipeurus procellariae
TextSentencer_T117 9479-9498 Sentence denotes Halipeurus diversus
TextSentencer_T118 9499-9515 Sentence denotes Puffinus griseus
TextSentencer_T119 9516-9535 Sentence denotes Halipeurus diversus
TextSentencer_T120 9536-9554 Sentence denotes Trabeculus hexacon
TextSentencer_T121 9555-9573 Sentence denotes Trabeculus hexacon
TextSentencer_T122 9574-9589 Sentence denotes Naubates prioni
TextSentencer_T123 9590-9614 Sentence denotes Notiopsylla kerguelensis
TextSentencer_T124 9616-9641 Sentence denotes Paramonostomum signiensis
TextSentencer_T125 9642-9667 Sentence denotes Paramonostomum signiensis
TextSentencer_T126 9668-9689 Sentence denotes Lateriporus australis
TextSentencer_T127 9690-9711 Sentence denotes Lateriporus australis
TextSentencer_T128 9712-9733 Sentence denotes Lateriporus australis
TextSentencer_T129 9734-9751 Sentence denotes Nototaenia fileri
TextSentencer_T130 9752-9800 Sentence denotes Nototaenia fileri 1 (78) Gymnophallus deliciosus
TextSentencer_T131 9801-9819 Sentence denotes Quadraceps ornatus
TextSentencer_T132 9820-9839 Sentence denotes Diplostomum minutum
TextSentencer_T133 9840-9858 Sentence denotes Quadraceps ornatus
TextSentencer_T134 9859-9882 Sentence denotes Diplostomum antarcticum
TextSentencer_T135 9883-9901 Sentence denotes Saemundssonia lari
TextSentencer_T136 9902-9925 Sentence denotes Diplostomum dominicanum
TextSentencer_T137 9926-9944 Sentence denotes Saemundssonia lari
TextSentencer_T138 9945-9966 Sentence denotes Hymenolepis arctowski
TextSentencer_T139 9967-9982 Sentence denotes Naubates prioni
TextSentencer_T140 9983-10005 Sentence denotes Anomotaenia dominicana
TextSentencer_T141 10006-10024 Sentence denotes Reighardia sternae
TextSentencer_T142 10025-10115 Sentence denotes Paramonostomum antarcticum 2 (64) Paramonostomum antarcticum 2 (79) Corynosoma shackletoni
TextSentencer_T143 10116-10138 Sentence denotes Corynosoma shackletoni
TextSentencer_T144 10139-10157 Sentence denotes Corynosoma hamanni
TextSentencer_T145 10158-10181 Sentence denotes Gymnophallus deliciosus
TextSentencer_T146 10182-10202 Sentence denotes Eulimdana rauschorum
TextSentencer_T147 10203-10217 Sentence denotes Sterna vittata
TextSentencer_T148 10218-10234 Sentence denotes Quadraceps houri
TextSentencer_T149 10235-10257 Sentence denotes Saemundssonia lockleyi
TextSentencer_T150 10258-10695 Sentence denotes Saemundssonia lockleyi 1 (98) A Antibodies, I Zlotorzycka and Modrzejewska (1992) , (56) Bergstrom et al. (1999a) , (57) Weimerskirch (2004), (58) Wilson (1970) , (59) Leotta et al. (2003) , (60) , (61) Bell et al. (1988) , (62) Rounsevell and Horne (1986) , (63) Horne and Rounsevell (1982) , (64) Odening (1982b) , (65) Brown (1966) , (66) Pilgrim (1998) , (67) Chastel and Beaucournu (1992) , (68) Mironov ( humans (Waldenstrom et al.
TextSentencer_T151 10696-11075 Sentence denotes 2002) , and are transmitted by contaminated food or water; Pasteurella multocida, responsible for avian cholera, can be transmitted by aerosols (Simensen and Olson 1980) or by contaminated food or water (Botzler 1991) ; Escherichia coli, although generally part of the natural bacterial flora in birds, can become pathogenic in conjunction with other infections (Morishita et al.
TextSentencer_T152 11076-11249 Sentence denotes 1999 ); Chlamidya sp. which is responsible for psittacosis and is transmitted mainly by aerosols, contaminated water, and by blood-suckling ectoparasites (Harkinezhad et al.
TextSentencer_T153 11250-11257 Sentence denotes 2009 ).
TextSentencer_T154 11258-11328 Sentence denotes Finally, at least five species of Salmonella were detected (Table 1) .
TextSentencer_T155 11329-11467 Sentence denotes Interestingly, Salmonella was not only found in scavenging species, such as skuas and giant petrels, but also in albatrosses and penguins.
TextSentencer_T156 11468-11609 Sentence denotes These bacteria are common inhabitants of the intestinal tract of birds, and are usually the cause of disease only under conditions of stress.
TextSentencer_T157 11610-11754 Sentence denotes Birds contract the bacteria either through direct contact with infected birds or through ingestion of contaminated food or water (Tizard 2004) .
TextSentencer_T158 11755-12032 Sentence denotes It is also interesting to note that in some species (i.e., pygoscelis penguins) reported results have been negative not only for Campylobacter sp., Campylobacter jejuni, but also for C. lari and for Salmonella in some locations, while in others the bacteria have been detected.
TextSentencer_T159 12033-12189 Sentence denotes This suggests that the distribution of these bacteria could be restricted to specific locations such as the proximity of research stations (Bonnedahl et al.
TextSentencer_T160 12190-12286 Sentence denotes 2005) or that resistance of the host may differ among different populations of the same species.
TextSentencer_T161 12287-12351 Sentence denotes Protozoa detected in Antarctica belong to six genera (Table 1) .
TextSentencer_T162 12352-12435 Sentence denotes Two are blood parasites present in sub-Antarctic islands, but absent in Antarctica.
TextSentencer_T163 12436-12549 Sentence denotes This mirrors the presence of suitable vectors for their transmission that are absent in Antarctica (Merino et al.
TextSentencer_T164 12550-12557 Sentence denotes 1997) .
TextSentencer_T165 12558-12711 Sentence denotes However, other such as the role of immunocompetence in preventing infection by blood-parasites in marine birds cannot be excluded (Martinez-Abrain et al.
TextSentencer_T166 12712-12719 Sentence denotes 2004 ).
TextSentencer_T167 12720-12799 Sentence denotes The remaining four genera are coccidian found in the intestinal tract of birds.
TextSentencer_T168 12800-12969 Sentence denotes Note that only one species has been identified, while most could only be identified to genus level because of the failure of the oocysts to sporulate (Golemansky 2003) .
TextSentencer_T169 12970-13083 Sentence denotes Antarctic birds host 39 species and four genera not identified as specific gastrointestinal parasites (Table 1) .
TextSentencer_T170 13084-13305 Sentence denotes The most frequently recorded species are the cestodes Parorchites zederi and Tetrabothrius pauliani, the nematode Stegophorus macronectes, the acanthocephalan Corynosoma hamanni, and the trematoda Gymnophallus deliciosus.
TextSentencer_T171 13306-13443 Sentence denotes The cestodes and nematode mainly infect penguin species, as well as sheathbills (Chionis alba) and giant petrels (Macronectes giganteus).
TextSentencer_T172 13444-13614 Sentence denotes In contrast, acanthocephalan and trematoda mainly infect not only kelp gulls (Larus dominicanus) and skuas (Catharacta lonnbergi and C. maccormicki) but also sheathbills.
TextSentencer_T173 13615-13758 Sentence denotes Infestations by cestodes, nematodes, acanthocephalan, and trematoda are strongly influenced by the foraging habits of the hosts (Hoberg 1996) .
TextSentencer_T174 13759-13852 Sentence denotes General foragers would be expected to be infested by more parasites than specialized species.
TextSentencer_T175 13853-14005 Sentence denotes For instance, the bird species infected by the most species of parasites are sheathbills (14 species) and Kelp gulls (12 species), both are generalists.
TextSentencer_T176 14006-14162 Sentence denotes In comparison, species highly specialized in krill (Euphausia spp.) like Chinstrap penguins are only infested by four species of gastrointestinal parasites.
TextSentencer_T177 14163-14303 Sentence denotes Corynosoma matures in the intestinal tract of mammals and birds; fish and aquatic invertebrates often serve this worm as intermediate hosts.
TextSentencer_T178 14304-14476 Sentence denotes However, since euphausiids are not part of the intermediate hosts of Corynosoma, infestation rates are low krill-dependent species like penguins (Muzaffar and Jones 2004) .
TextSentencer_T179 14477-14590 Sentence denotes The most numerous of parasites in Antarctic and sub-Antarctic birds are ectoparasites with 75 species (Table 1) .
TextSentencer_T180 14591-14784 Sentence denotes Lice (Phthiraptera) are the most abundant with 66 species, and some very well-represented genera such as Austrogoniodes sp., Docophoroides sp., Naubates sp., Trabeculus sp. or Saemundssonia sp.
TextSentencer_T181 14785-14968 Sentence denotes Other ectoparasites include the feather mites Zachvatknia sp, Alloptes sp., and Scutomegninia sp., ticks, of the Ixodes genus and the endemic Antarctic flea Glacyopsillus antarcticus.
TextSentencer_T182 14969-15123 Sentence denotes Finally, only one fungus infection by Thelebolus microsporus was reported in skuas, and two by the pentastomid Reighardia sternae in skuas and Kelp gulls.
TextSentencer_T183 15124-15212 Sentence denotes Antarctic and Sub-Antarctic birds host a total of 173 parasites or pathogenic organisms.
TextSentencer_T184 15213-15304 Sentence denotes The most diversified group in terms of number of species is ectoparasites, especially lice.
TextSentencer_T185 15305-15524 Sentence denotes Although most of them seem to be located in the sub-Antarctic region, birds living in continental Antarctica, such as Emperor (Aptenodytes forsteri) and Adelie penguins (Pygoscelis adeliae) are parasitized by some lice.
TextSentencer_T186 15525-15619 Sentence denotes This suggests that lice are not limited by the environmental conditions of polar environments.
TextSentencer_T187 15620-15865 Sentence denotes However, these harsh conditions seem to limit the diversity and abundance of parasitic protozoa, which are represented by only six genera, specifically blood parasites, as these organisms need an arthropod vector to infect the birds (see above).
TextSentencer_T188 15866-15987 Sentence denotes The second most abundant group is the bacteria, which is clearly correspond to this group's enormous diversity elsewhere.
TextSentencer_T189 15988-16106 Sentence denotes However, little is known about the community of potential pathogenic bacteria present in Antarctic birds (Kerry et al.
TextSentencer_T190 16107-16114 Sentence denotes 1999) .
TextSentencer_T191 16115-16296 Sentence denotes The presence of viruses is difficult to evaluate because no disease-causing virus has yet been isolated in Antarctica, although certain virus antibodies have been found (see above).
TextSentencer_T192 16297-16390 Sentence denotes Therefore, more attention must be given to the isolation of pathogenic viruses in Antarctica.
TextSentencer_T193 16391-16646 Sentence denotes Geographical variation in the distribution of reported parasites, pathogens and diseases shows that 63 of these organisms (eight bacteria, six viruses, two protozoa, 18 gastrointestinal parasites and 29 ectoparasites) are present in sub-Antarctic islands.
TextSentencer_T194 16647-16912 Sentence denotes Sixty organisms (32 bacteria, two viruses, two protoza, 23 gastro-intestinal parasites and one ectoparasite) are present in the South Shetlands and 23 in the continental Antarctic Peninsula (10 bacteria, two virus, two protozoa and nine gastrointestinal parasites).
TextSentencer_T195 16913-17088 Sentence denotes In continental Antarctica, there are 19 parasites or pathogens (two bacteria, four viruses, one protozoon, four gastrointestinal parasites and eight ectoparasites) (Table 1 ).
TextSentencer_T196 17089-17334 Sentence denotes It is difficult to interpret these apparent differences in distribution from a biological point of view, because they probably reflect differences in research effort in the various Antarctic regions rather than any actual geographical variation.
TextSentencer_T197 17335-17483 Sentence denotes For instance, the largest number of organisms was found at the South Shetlands where also most of the relevant research has been done in Antarctica.
TextSentencer_T198 17484-17628 Sentence denotes However, ectoparasites seem to be more common in the sub-Antarctic islands, which is to be expected from their dependency on thermal conditions.
TextSentencer_T199 17629-17838 Sentence denotes On the other hand, more ectoparasite species have been found in continental Antarctica than in the South Shetlands or the Antarctic Peninsula, which is contrary to expectations from a biological point of view.
TextSentencer_T200 17839-17933 Sentence denotes These results probably reflect the differential attention paid to this group in these regions.
TextSentencer_T201 17934-17987 Sentence denotes The distribution of bacteria also supports this idea.
TextSentencer_T202 17988-18123 Sentence denotes To determine the actual distribution of these organisms the absence of parasites or pathogens in Antarctica must be considered as well.
TextSentencer_T203 18124-18208 Sentence denotes However, only nine out of 98 studies reported negative findings (i.e., Merino et al.
TextSentencer_T204 18209-18232 Sentence denotes 1997 , Bonnedahl et al.
TextSentencer_T205 18233-18240 Sentence denotes 2005 ).
TextSentencer_T206 18241-18457 Sentence denotes This kind of information is as important as positive findings as it may aid to establish the time they may have been present, to determine the causes of their presence and to evaluate their impact on Antarctic fauna.
TextSentencer_T207 18458-18580 Sentence denotes To obtain the required information sample sizes have to be sufficiently large for results to be reliable (Bonnedahl et al.
TextSentencer_T208 18581-18588 Sentence denotes 2005) .
TextSentencer_T209 18589-18764 Sentence denotes The techniques used to detect the pathogens are also important, as in some cases the presence of these organisms is extrapolated from serological methods (i.e., Gardner et al.
TextSentencer_T210 18765-18772 Sentence denotes 1997) .
TextSentencer_T211 18773-19030 Sentence denotes The presence of antibodies suggests the exposure to a pathogen, but does not necessarily indicate its presence in that particular place, because the contact may have occurred elsewhere or in a particular time because the organisms may not always be present.
TextSentencer_T212 19031-19111 Sentence denotes This is especially important in migratory species such as skuas, gulls or terns.
TextSentencer_T213 19112-19219 Sentence denotes Moreover, it may indicate only the presence of a serologically related nonpathogenic organism (Kerry et al.
TextSentencer_T214 19220-19227 Sentence denotes 1999 ).
TextSentencer_T215 19228-19369 Sentence denotes Even given how little is known about endemic pathogen it is possible that our available test react with similar but as yet unknown organisms.
TextSentencer_T216 19370-19563 Sentence denotes Therefore, the presence of pathogenic organisms inferred from antibodies in either species or location should be taken with caution, and studies addressing their isolation should be encouraged.
TextSentencer_T217 19564-19633 Sentence denotes The effects of parasites in Antarctic birds have been studied little.
TextSentencer_T218 19634-19722 Sentence denotes Ixodes uriae has attracted more attention than any other parasite (Gauthier-Clerc et al.
TextSentencer_T219 19723-19745 Sentence denotes 1998; Bergstrom et al.
TextSentencer_T220 19746-19769 Sentence denotes 1999a, b; Mangin et al.
TextSentencer_T221 19770-19790 Sentence denotes 2003 among others) .
TextSentencer_T222 19791-19894 Sentence denotes In general, ticks may be causing delayed growth (Moreby 1996) and mortality in chicks (Bergstrom et al.
TextSentencer_T223 19895-19973 Sentence denotes 1999a) , affecting the host population dynamics (Boulinier and Danchin 1996) .
TextSentencer_T224 19974-20131 Sentence denotes Other parasites have been given less attention, and studies dealing with the effects of parasites may be considered almost anecdotic (e.g., Quillfeldt et al.
TextSentencer_T225 20132-20180 Sentence denotes 2004 for effects of chewing lice on physiology).
TextSentencer_T226 20181-20391 Sentence denotes Therefore, because of the lack of studies, the probable effects of parasites on Antarctic avifauna must be extrapolated from information taken in other organisms or in other latitudes, reducing its reliability.
TextSentencer_T227 20392-20463 Sentence denotes Therefore, further studies are required to shed light on the situation.
TextSentencer_T228 20464-20708 Sentence denotes Another gap in the information reviewed is that most of the publications only provide descriptive data about the presence of the parasites, pathogens or diseases, and only a few give information on the prevalence and/or intensity of parasitism.
TextSentencer_T229 20709-20836 Sentence denotes Only 16 out of 101 papers reviewed focused on physiology related to parasitism or diseases, and most of these were in penguins.
TextSentencer_T230 20837-20967 Sentence denotes Thus, it may be concluded that the information published about diseases and parasites in Antarctic birds is scarce and fragmental.
TextSentencer_T231 20968-21153 Sentence denotes Moreover, some studies were undertaken at least 20 years ago and in others pathogens were detected through traditional techniques, which are less reliable than modern molecular methods.
TextSentencer_T232 21154-21221 Sentence denotes Overall little is known about which diseases are endemic or exotic.
TextSentencer_T233 21222-21360 Sentence denotes Knowledge about the presence of disease and parasites is crucial to understand how Antarctica is functioning in terms of ecosystem health.
TextSentencer_T234 21361-21449 Sentence denotes This information is important to the decision-making process in conservation management.
TextSentencer_T235 21450-21599 Sentence denotes The possibility that emergent infectious diseases could cause a catastrophic extinction of bird populations is a plausible scenario (Van Riper et al.
TextSentencer_T236 21600-21706 Sentence denotes 1986) although there is only one documented case of extinction by infection (Daszak and Cunningham 1999) .
TextSentencer_T237 21707-21879 Sentence denotes Antarctica is not beyond this risk, animals affected by new pathogens or parasites can be severely affected due to their less effective immunological systems (Merino et al.
TextSentencer_T238 21880-21887 Sentence denotes 2001) .
TextSentencer_T239 21888-22030 Sentence denotes Moreover, the presence of pollutants in the environment can depress the immune system, increasing the magnitude of such effects (Briggs et al.
TextSentencer_T240 22031-22038 Sentence denotes 1997) .
TextSentencer_T241 22039-22238 Sentence denotes As infestation by a great number of parasites, like gastrointestinal parasites, is dependent on feeding habits (Hoberg 1996) , changes in prey can play an important role in exposure to new parasites.
TextSentencer_T242 22239-22308 Sentence denotes Changes in diet may be a consequence of climate change (Emslie et al.
TextSentencer_T243 22309-22344 Sentence denotes 1998) or overexploitation of krill.
TextSentencer_T244 22345-22521 Sentence denotes We, therefore, need to improve our knowledge of physiological functions, such as the immune system, to understand the biological basis for disease and the effects of parasites.
TextSentencer_T245 22522-22620 Sentence denotes Another point of critical importance concerning disease in Antarctica is related to public health.
TextSentencer_T246 22621-22903 Sentence denotes Most human emergent infectious diseases are acquired from exposure to pathogens transmitted naturally between animals and humans, that is, by zoonotic transmission and wildlife play a key role by providing reservoirs to unknown pathogens responsible for such diseases (Daszak et al.
TextSentencer_T247 22904-22911 Sentence denotes 2000) .
TextSentencer_T248 22912-23166 Sentence denotes Although Antarctica can still be considered an isolated continent, the presence of thousands of people each austral summer could increase the risk of zoonosis, although only a small part of those people have close contact with Antarctic birds or mammals.
TextSentencer_T249 23167-23320 Sentence denotes Influenza, caused by a virus, and Lyme disease, caused by the bacteria Borrelia burgdorferi, are two examples of this kind of potential zoonotic disease.
TextSentencer_T250 23321-23445 Sentence denotes Finally, Kerry et al. (1999) made several recommendations for reducing the risk of humans introducing disease in Antarctica.
TextSentencer_T251 23446-23625 Sentence denotes These included setting up a ''central clearinghouse for information on suspected disease occurrences'' (Recommendation 4) and ''establishment of serum banks'' (Recommendation 19).
TextSentencer_T252 23626-23763 Sentence denotes However, 10 years after their presentation to the Antarctic Treaty, to our knowledge, such recommendations have not yet been implemented.
TextSentencer_T253 23764-23974 Sentence denotes Specifically, these two recommendations must be complied with to improve our knowledge about the health of bird and mammals populations in Antarctica to help prevent outbreaks or make decisions when they occur.