Dracunculus medinensis, or human Guinea worm (GW), causes a painful and debilitating infection. The global Guinea Worm Eradication Program (GWEP) has successfully reduced human GW cases from 3.5 million in 21 countries in 1986 to only 30 cases in three remaining countries in 2017. Since 2012, an increase in GW infections in domestic dogs, cats and baboons has been reported. Because these infections have not followed classical GW epidemiological patterns resulting from water-borne transmission, it has been hypothesized that transmission occurs via a paratenic host. Thus, we investigated the potential of aquatic animals to serve as paratenic hosts for D. medinensis in Chad, Africa. During three rainy and two dry season trips we detected no GW larvae in 234 fish, two reptiles and two turtles; however, seven GW larvae were recovered from 4 (1.4%) of 276 adult frogs. These data suggest GW infections may occur from ingestion of frogs but the importance of this route is unknown. Additional studies are needed, especially for other possible routes (e.g., ingestion of fish intestines that were recently shown to be a risk). Significantly, 150 years after the life cycle of D. medinensis was described, our data highlights important gaps in the knowledge of GW ecology.

BackgroundAnaplasma spp. are Gram-negative obligate intracellular bacteria transmitted by ticks. Even though numerous studies have detected DNA from Anaplasma spp. in the blood of birds, thus far mammals were the only vertebrates demonstrated to serve as competent hosts to these organisms. We report a novel candidate species of Anasplasma that was associated with cytoplasmic inclusions in the erythrocytes of an African penguin (Spheniscus demersus) in South Africa.MethodsCytoplasmic inclusions were morphologically characterized from freshly-produced blood smears, and phylogenetic analysis of 16S rRNA and groEL genes were used to evaluate the evolutionary relationships of the organism to other Anaplasmataceae.ResultsDark-purple round or oval inclusions consistent with Anaplasmataceae morulae were observed in the cytoplasm of erythrocytes. Phylogenetic trees produced using different methods agreed that the organism detected in this study belongs to the genus Anaplasma, and suggested that it is most closely related to the cluster comprising A. centrale, A. capra, A. marginale and A. ovis. We propose provisionally naming the strain detected in this study as “Candidatus Anaplasma sphenisci”.ConclusionsThis is the first species of Anaplasma shown to produce cytoplasmic inclusions in avian cells, opening the possibility that cytoplasmic inclusions in avian erythrocytes that had previously been attributed to Aegyptianella sp. might in fact correspond to Anaplasma. Further studies on the molecular biology of avian-infecting Anaplasmataceae will be valuable to provide insight into the evolution and epidemiology of these organisms.Electronic supplementary materialThe online version of this article (10.1186/s13071-018-3089-9) contains supplementary material, which is available to authorized users.

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The Magellanic Penguin ( Spheniscus magellanicus) is native to Argentina, Chile, and the Falkland/Malvinas Islands, and is a regular winter migrant in Uruguayan and Brazilian coastal waters. The species is known to be susceptible to a variety of gastrointestinal nematodes, cestodes, trematodes, and acanthocephalans, as well as renal trematodes and pulmonary nematodes. Schistosomes (Platyhelminthes, Trematoda, Schistosomatidae) and microfilariae (Nematoda, Secernentea, Onchocercidae) were histologically identified in Magellanic Penguins ( Spheniscus magellanicus) that died while under care at rehabilitation centers in southern Brazil. Phylogenetic analysis of the COI gene, ITS-1 region, 5.8S rRNA gene, ITS-2 region, and 28S rRNA gene sequences of the schistosome revealed that it is closely related to, but distinct from, a schistosome reported from the African Penguin ( Spheniscus demersus). The schistosomes from Magellanic and African Penguins were grouped with Gigantobilharzia huronensis, Gigantobilharzia melanoidis, and Dendritobilharzia pulvurenta; however, the lack of a clearly monophyletic origin precludes determining their genus. The incidental discovery of novel parasites during a study that did not specifically aim to investigate the occurrence of helminths underscores the value of histopathological examination as an exploratory diagnostic approach.

The Borrelia genus contains two major clades, the Lyme borreliosis group, which includes the causative agents of Lyme disease/borreliosis (B. burgdorferi sensu stricto and other related B. burgdorferi sensu lato genospecies), and the relapsing fever borreliosis group (B. hermsii, B. turicatae, and B. parkeri). Other unclassified reptile- and echidna-associated Borrelia spp. (i.e., B. turcica and ‘Candidatus Borrelia tachyglossi’, respectively) do not belong in either of these two groups. In North America, Borrelia spp. from both of the major clades are important pathogens of veterinary and public health concern. Lyme disease is of particular interest because the incidence in the northeastern United States continues to increase in both dogs and humans. Birds have a potentially important role in the ecology of Borrelia species because they are hosts for numerous tick vectors and competent hosts for various Borrelia spp. Our goal was to investigate the prevalence of Borrelia spp. in four free-living species of upland game birds in Pennsylvania, USA including wild turkey (Meleagris gallopavo), ruffed grouse (Bonasa umbellus), ring-necked pheasants (Phasianus colchicus), and American woodcock (Scolopax minor). We tested 205 tissue samples (bone marrow and/or spleen samples) from 169 individuals for Borrelia using a flagellin gene (flab) nested PCR, which amplifies all Borrelia species. We detected Borrelia DNA in 12% (24/205) of samples, the highest prevalence was in wild turkeys (16%; 5/31), followed by ruffed grouse (13%; 16/126) and American woodcock (3%; 1/35). All pheasants (n = 13) were negative. We sequenced amplicons from all positive game birds and all were B. burgdorferi sensu stricto. Our results support previous work indicating that certain species of upland game birds are commonly infected with Borrelia species, but unlike previous studies, we did not find any relapsing fever borreliae.

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The Prince Edward Islands are Subantarctic islands in the southwest Indian Ocean that are of global importance as seabird nesting sites, and are breeding grounds for five species of albatrosses (Procellariiformes: Diomedeidae). In March–April 2016 numerous chicks of one of these species, the grey-headed albatross (Thalassarche chrysostoma), were found dead at colonies on Marion Island (46°57′S 37°42′E), the larger of the two Prince Edward Islands. Affected chicks were weak, prostrated, apathetic, had drooping wings, and many eventually died while sitting on the nest. Five carcasses were necropsied, and samples were obtained for pathological and parasitological analysis. Four chicks appeared to have died from starvation, and one died due to air-sac helminthiasis, with extensive hemorrhage in the air sacs and multifocal pyogranulomatous air-sacculitis. The air sac parasites were identified as Diomedenema diomedeae (Aproctoidea: Desmidocercidae). Phylogenetic analysis of the nuclear 18S rRNA gene and mitochondrial COI gene confirmed that D. diomedeae belongs to the suborder Spirurina and showed that it is most closely related to the Diplotriaenidae (superfamily Diplotriaenoidea), a family of parasites that infect the air sacs and subcutaneous tissues of a variety of bird species. To our knowledge this is the first record of the occurrence of a nematode in the respiratory tract of an albatross and the first study to provide DNA sequences for a species of the superfamily Aproctoidea.