Aspects of the development of Ixodes anatis under different environmental conditions in the laboratory and in the field.

BACKGROUND: Numerous laboratory and fewer field-based studies have found that ixodid ticks develop more quickly and survive better at temperatures between 18 °C and 26 °C and relative humidity (RH) between 75 and 94%. Ixodes anatis Chilton, 1904, is an endophilic, nidicolous species endemic to North Island brown kiwi (Apteryx mantelli) (NIBK) and the tokoeka (Apteryx australis), and little is known about the environmental conditions required for its development. The aims of this study were to determine and compare the conditions of temperature and RH that ensure the best survival of the kiwi tick and the shortest interstadial periods, in laboratory conditions and outdoors inside artificial kiwi burrows. METHODS: Free-walking engorged ticks were collected off wild kiwi hosts and placed in the laboratory under various fixed temperature and humidity regimes. In addition, sets of the collected ticks at different developmental stages were placed in artificial kiwi burrows. In both settings, we recorded the times taken for the ticks to moult to the next stage. RESULTS: Larvae and nymphs both showed optimum development at between 10 °C and 20 °C, which is lower than the optimum temperature for development in many other species of ixodid ticks. However, larvae moulted quicker and survived better when saturation deficits were < 1-2 mmHg (RH > 94%); in comparison, the optimum saturation deficits for nymph development were 1-10 mmHg. CONCLUSIONS: Our results suggest that the kiwi tick has adapted to the stable, but relatively cool and humid conditions in kiwi burrows, reflecting the evolutionary consequences of its association with the kiwi.

Epidemiologic significance of Toxoplasma gondii infections in turkeys, ducks, ratites and other wild birds: 2009-2020.

Toxoplasma gondii infections are common in humans and animals worldwide. Wild and domestic avian species are important in the epidemiology of T. gondii infections because felids prey on them and excrete millions of oocysts in the environment, disseminating the infection. Herbivorous birds are also excellent sentinels of environmental contamination with T. gondii oocysts because they feed on the ground. Toxoplasma gondii infections in birds of prey reflect infections in intermediate hosts. Humans can become infected by consuming undercooked avian tissues. Here, the authors reviewed prevalence, persistence of infection, clinical disease, epidemiology and genetic diversity of T. gondii strains isolated from turkeys, geese, ducks, ratites and avian species (excluding chickens) worldwide 2009-2020. Genetic diversity of 102 T. gondii DNA samples isolated worldwide is discussed. The role of migratory birds in dissemination of T. gondii infection is discussed.

Comparing the Mini-FLOTAC and centrifugal faecal flotation for the detection of coccidia (Eimeria spp.) in kiwi (Apteryx mantelli).

Coccidia (Eimeria spp.) in brown kiwi (Apteryx mantelli) cause significant morbidity and mortality in captive rearing facilities. Monitoring the abundance of this parasite in individual birds is crucial for successful management of kiwi. This research compares the abilities of centrifugal faecal flotations (CFF) and a modified Mini-FLOTAC protocol to detect oocysts. We hypothesised that the Mini-FLOTAC would detect higher oocyst counts. Kiwi dropping samples (n = 10) were homogenized in MgSO4 (SG 1.28) and oocyst counts made with CFFs and Mini-FLOTAC counting chambers, with three replicates for each method. For CFF, 0.5 g of droppings were examined using standard methods. Mini-FLOTAC counts were made using a modified sample preparation compared with the manufacturer's protocol but still used a 1:20 dilution of droppings. Oocysts were quantified using light microscopy at ×100-300 magnification. A linear mixed-effects model by REML showed that oocyst per gram estimates via the Mini-FLOTAC method were 3.2 times higher (95% CI 2.4-4.5, p < 0.01) than the CFF results. This increased detection likely represents a more accurate estimation of parasite shedding and should be considered for use in research or applications requiring more accuracy, cost-effectiveness, or accessibility than the CFF provides.

Extensive in situ radiation of feather lice on tinamous.

Tinamous host the highest generic diversity of lice of any group of birds, as well as hosting representatives of all four avian feather louse ecomorphs. Although the generic diversity of tinamou feather lice is well documented, few attempts have been made to reconstruct the phylogenetic relationships among these lice. To test whether tinamou feather lice form a monophyletic group as a whole, we used whole-genome sequencing to estimate a higher-level phylogeny of tinamou feather lice, together with a broad diversity of other avian feather louse groups. In total, we analysed sequences from over 1000 genes for 48 genera of avian lice using both concatenated and coalescent approaches to estimate the phylogeny of this diverse group of avian feather lice. Although the body louse ecomorph of tinamou feather lice formed a monophyletic group, they did not strictly form a monophyletic group together with the other three ecomorphs of tinamou feather lice. In particular, a clade comprised of several feather louse genera, mainly from South America, is nested phylogenetically within tinamou lice, which also have their main centre of diversity in South America. These results suggest in situ radiation of these parasites in South America.

Prevalence of Anti-Toxoplasma Gondii Antibodies in Ratites from Brazil.

The prevalence of anti-Toxoplasma gondii antibodies was investigated among 104 ratites: 68 rheas (Rhea americana), 16 emus (Dromaius novaehollandiae), and 20 ostriches (Struthio camelus) in 4 Brazilian states. The prevalence in rheas was 26.5% (18 of 68), and titers were 1:100 (n = 8), 1:200 (n = 1), 1:400 (n = 4), 1:800 (n = 4), and 1:1,600 (n = 1). In emus, the prevalence was 50% (8 of 16), and titers were 1:50 (n = 1) and 1:100 (n = 7). The ostriches were slaughtered for human consumption, and 80% (16 of 20) were seropositive with titers of 1:200 (n = 1), 1:400 (n = 9), and 1:800 (n = 6). Sera were tested with a modified agglutination test, and the results confirmed the distribution of the parasite in ratite species from Brazil. The data obtained in this study show that T. gondii is prevalent among ratites from Brazil, and therefore ratite meat should also be considered a potential source of human infection. This is the first report of T. gondii seroprevalence in emus.

Factors affecting abundance of different stages of the endophilic tick Ixodes anatis in brown kiwi (Apteryx mantelli) shelters.

Ixodes anatis is a species of endophilic (nidicolous) tick species parasitizing brown kiwi (Apteryx mantelli). Even though they are endemic to New Zealand like their host, very little is known about these ticks or their population dynamics and relationships with their hosts. We conducted a study from May 2013 to June 2014 to evaluate the effect of shelter location (one of three gullies), habitat (forest, scrub and pasture) and type (tree, soil and surface) on the abundance of the different life stages of I. anatis. In total, 12,172 ticks were collected from 63 shelters, which were sampled monthly for 11 months over the 14 month period. Un-engorged larvae predominated over other stages accounting for 87.2% of the samples collected. We found that location, habitat in which the shelters were located, and the type of shelter were significant predictors of I. anatis abundance. Tree shelters in forests had significantly higher tick abundance than those in scrub and pasture. Tree and soil shelters in general had significantly more ticks than surface shelters. Shelters located in Kauri Bush a drier site, had higher abundances than those in wetter sites. While some of these changes can be explained with the movement of the host, we believe more research needs to be done on the effect of shelters' microclimate on I. anatis' life cycle.

The circadian variation of oocyst shedding of Eimeria spp. affecting brown kiwi (Apteryx mantelli).

Captive rearing of wild brown kiwi (Apteryx mantelli) is widely carried out to assist in the recovery of this declining species. As a consequence, high densities of immunologically naïve kiwi are commonly housed in semi-captive conditions, with the potential to result in substantial morbidity and mortality from coccidiosis caused by multiple species of Eimeria. Previous research has described circadian variation in oocyst shedding across multiple avian host species. The aim of this research was to describe any circadian variation in oocyst shedding in brown kiwi. Droppings were collected from brown kiwi (n = 4) at a single captive rearing facility using video surveillance to determine the time of excretion, and oocyst counts were undertaken. Results show that two of the Eimeria spp. affecting brown kiwi exhibit a peak in oocyst shedding between 03.00 and 07.00 with few or no oocysts shed between 08.00 and midnight. These results are not able to be explained by the current hypotheses theorising the evolutionary forces behind the development of this adaptive trait. Our findings increase the current understanding of the biology of the Eimeria spp. affecting brown kiwi and have important implications for the management of captive-reared kiwi, in particular for the accurate interpretation of faecal oocyst counts.

Redescription of the kiwi tick Ixodes anatis (Acari: Ixodidae) from New Zealand, with notes on its biology.

Ixodes anatis Chilton is of veterinary and conservation importance in New Zealand due to its association with the threatened kiwi (Aves: Apterygidae: Apteryx spp.). Since the tick's description in 1904, there has been debate regarding its correct taxonomic position and nomenclature. Herein all life stages of this species are redescribed and accompanied by electron micrographs and drawings. The systematics, host preferences, distribution, disease relationships and conservation biology of the species are also discussed.

Description of four new species of coccidia (Apicomplexa: Eimeriidae) from brown kiwi, Apteryx mantelli, in New Zealand.

This study used morphological techniques to describe and name four new species of coccidia from the brown kiwi (Apteryx mantelli). Four distinct eimerian oocyst species were recovered that we describe as new species. The largest of these, Eimeria paraurii n. sp. measured 32.2 × 19.8 µm and is morphologically similar to gametocytes previously described histologically in colorectal polyps (Morgan et al. in Parasitol Res 111(4):1689-1699, 2012). Eimeria apteryxii n. sp. measured 23.9 × 14.9 µm and is similar to renal oocysts described histologically in brown, rowi (A. rowii) and Haast tokoeka kiwi (A. australis "Haast") (Morgan et al. in Avian Pathol 42(2):137-146, 2013). Eimeria kiwii n. sp. measured 14.8 × 13.9 µm and resembled gametocytes described previously in kiwi intestinal epithelial cells in brown kiwi (Morgan et al. in Parasitol Res 111(4):1689-1699, 2012). Eimeria mantellii n. sp. measured 17.8 × 10.7 µm and did not appear similar to any coccidia previously described in histological studies in kiwi. These are the first species of Eimeria to be described and named from brown kiwi. Because the morphological descriptions in the present study were determined from a limited number of kiwi droppings from two geographical locations, it is likely that these represent only a portion of Eimeria species present in other populations of both brown kiwi and other Apteryx species from around New Zealand.

A new feather mite species of the genus Neumannella Trouessart, 1916 (Analgoidea, Dermoglyphidae) from the Red-winged Tinamou Rhynchotus rufescens (Temminck, 1815) (Aves, Tinamiformes) with remarks to the evolution of host-parasite associations of the genus.

Neumannella skorackii, a new species of the feather mite family Dermoglyphidae (Acari, Astigmata) is described from the Red-winged Tinamou Rhynchotus rufescens (Temminck, 1815) (Aves, Tinamiformes) from Paraguay and a key to all known species of the genus is provided. The phylogenetic relationships (MP analysis of 25 morphological characters) between Neumannella species along with the evolutionary history of host-parasite associations revealed by Jungle reconciliation method are reconstructed. Relatively low cospeciation contribution to the recent host-parasite associations is discovered.

Enteric coccidiosis in the brown kiwi (Apteryx mantelli).

Enteric coccidiosis may cause significant morbidity and mortality in juvenile brown kiwi (Apteryx mantelli). Morphology of sporulated oocysts indicates that at least two Eimeria species are able to infect the brown kiwi. A histological study of the endogenous stages of coccidia was undertaken in the intestinal tracts of ten naturally infected young kiwi. Sequential sectioning of the entire intestinal tract allowed identification and recording of the distribution of the various coccidial life stages. Macromeronts measuring 268 × 162 µm when mature were found mainly within the lamina propria of the proximal one third of the small intestine. A smaller form of lamina propria meront was also identified (8.7 × 6.4 µm) with a similar distribution to the macromeronts. Small meronts (4.4 × 3.8 µm) were also identified in mucosal epithelial cells, with the overall peak in distribution within the intestinal tract being distal to the lamina propria meronts. Three morphologically distinctive gametocytes were identified. Type A gametocytes contained within epithelial cells shared the same distribution as the epithelial meronts. Polyps containing large numbers of type B gametocytes within the distal intestinal tract were found in two cases, and type C gametocytes were identified throughout the entire intestinal tract in one case only. The observational nature of this study precludes complete knowledge of the parasite life cycles using histology alone. However, it is likely that each of the three morphologically distinct gametocytes represents a separate species of enteric coccidia.

A new quill mite species (Acari: Syringophilidae) parasitising tinamous (Aves: Tinamiformes).

Tinamiphilopsis ariconte n. sp., a syringophilid mite, is described from three tinamou species (Tinamidae), Rhynchotus rufescens (Temminck) and Nothura boraquira (Spix) in Paraguay and N. minor (Spix) in Brazil. These data indirectly support the hypothesis that the cheyletoid-like predatory ancestor of the Syringophilidae switched to parasitism before the divergence of the avian hosts into the two major clades Palaeognathae and Neognathae.

Molecular characterization of Babesia kiwiensis from the brown kiwi (Apteryx mantelli).

To further investigate the recently described avian piroplasm, Babesia kiwiensis, blood samples were collected from 13 wild-caught and 8 zoo-captive brown kiwi (Apteryx mantelli) and screened for the presence of piroplasm DNA using a nested-polymerase chain reaction (PCR) targeting the 18S rRNA gene of most members of Piroplasmida. All captive birds gave a negative PCR result, while 12 wild-caught birds were PCR positive. The nearly full-length 18S rRNA gene for B. kiwiensis was sequenced. Upon phylogenetic analysis, it was found to belong to the babesid group of piroplasms and was ancestral, yet genetically similar, to the Babesia canis-related species. An insight into the current taxonomy of the avian piroplasms is also given. An Ixodes anatis tick collected from 1 of the North Island brown kiwi was also screened using PCR and was found to be positive for B. kiwiensis DNA.

Infectious diseases and parasites of ratites.

This article discusses infectious and parasitic disease conditions in the three ratite species. Diseases and parasitic conditions are reviewed in relation to etiology, transmission, pathology, diagnosis, treatment, and prevention. To ensure optimum reproduction and growth of birds on large production units, a veterinarian must understand management in relation to biosecurity and disease problems.