Screening of protozoan and microsporidian parasites in feces of great cormorant (Phalacrocorax carbo)

The global epidemiology of Microsporidia infection in birds: A systematic review and meta-analysis

This study aimed to assess the global status and genetic diversity of Microsporidia infection in different birds. An online search was conducted in international databases from 1 January 1990 to 30 June 2022. A total of 34 articles (including 37 datasets) were included for the final meta-analysis. The pooled global prevalence of Microsporidia infection in birds was 14.6% (95% CI: 11.6-18.1). The highest prevalence of Microsporidia was found in wild waterfowl which was 54.5% (28.1-78.6). In terms of detection methods, the pooled prevalence was estimated to be 21.2% (95% CI: 12.1-34.4) and 13.4% (95% CI: 10.3-17.3) for using microscopic and molecular detection methods, respectively. Enterocytozoon bieneusi was the most common pathogen (24/31; 77.42% of the studies) according to PCR-based methods, and genotype D was the highest reported genotype (nine studies). In conclusion, designing strategies for the control and prevention of Microsporidia infection in birds should be recommended.

The risk of wild birds contaminating source water with zoonotic Cryptosporidium and Giardia is probably overestimated

Cryptosporidium and Giardia are important waterborne protozoan parasites that are resistant to disinfectants commonly used for drinking water. Wild birds, especially wild migratory birds, are often implicated in the contamination of source and wastewater with zoonotic diseases, due to their abundance near water and in urban areas and their ability to spread enteric pathogens over long distances. This review summarises the diversity of Cryptosporidium and Giardia in birds, with a focus on zoonotic species, particularly in wild and migratory birds, which is critical for understanding zoonotic risks. The analysis revealed that both avian-adapted and zoonotic Cryptosporidium species have been identified in birds but that avian-adapted Cryptosporidium species dominate in wild migratory birds. Few studies have examined Giardia species and assemblages in birds, but the non-zoonotic Giardia psittaci and Giardia ardeae are the most commonly reported species. The identification of zoonotic Cryptosporidium and Giardia in birds, particularly C. parvum and G. duodenalis assemblages A and B in wild migratory birds, is likely due to mechanical carriage or spillback from birds co-grazing pastures contaminated with C. parvum from livestock. Therefore, the role of wild migratory birds in the transmission of zoonotic Cryptosporidium and Giardia to source water is likely overestimated. To address knowledge gaps, it is important to conduct more extensive studies on the prevalence of Cryptosporidium and Giardia in a broader range of migratory wild birds. There is also a need to investigate the extent to which zoonotic infections with C. hominis/C. parvum and G. duodenalis assemblages A and B are mechanical and/or transient, and to assess the load and viability of zoonotic oo/cysts shed in avian faeces. Understanding the contribution of birds to zoonoses is essential for effective disease surveillance, prevention, and control.

Occurrence of Cryptosporidium and Giardia in wild birds from Qinghai Lake on the Qinghai-Tibetan Plateau, China

Cryptosporidium and Giardia are important intestinal zoonotic pathogens that can infect various hosts and cause diarrhoeal diseases. There are few reports of the epidemiological prevalence and molecular characterization of Cryptosporidium and Giardia in wild birds around Qinghai Lake and in the surrounding areas on the Qinghai-Tibetan Plateau, Northwest China. Therefore, the aim of this study was to determine the Cryptosporidium spp. and Giardia duodenalis genotypes and their epidemiological prevalence in wild birds by PCR amplification. To our knowledge, this is the first report of a variety of Cryptosporidium spp. and G. duodenalis infections in wild birds from that area, with overall prevalence rates of 8.98% (61/679) and 3.39% (23/679), respectively. Furthermore, PCR sequencing confirmed the presence of Cryptosporidium baileyi (n = 3), Cryptosporidium parvum (n = 58), and G. duodenalis assemblage B (n = 19) and E (n = 4) in wild birds from the areas around Qinghai Lake. The results of the present study demonstrated the wide distribution of Cryptosporidium and Giardia among wild birds, which has potential public health significance. Moreover, the study findings also provided useful molecular epidemiological data for monitoring and investigating the two parasitic protozoa in wild animals and surrounding environments.

Parasites of the Neotropic cormorant Nannopterum (Phalacrocorax) brasilianus (Aves, Phalacrocoracidae) in Chile

The Neotropic cormorant Nannopterum (Phalacrocorax) brasilianus (Suliformes: Phalacrocoracidae) is widely distributed in Central and South America. In Chile, information about parasites for this species is limited to helminths and nematodes, and little is known about other parasite groups. This study documents the parasitic fauna present in 80 Neotropic cormorants' carcasses collected from 2001 to 2008 in Antofagasta, Biobío, and Ñuble regions. Birds were externally inspected for ectoparasites and necropsies were performed to examine digestive and respiratory organs in search of endoparasites. Ectoparasites collected were cleared and mounted for identification under a microscope. Fecal samples were also evaluated to determine the presence of protozoan parasites employing a flotation technique. A total of 44 (42.5%) of birds were infested with at least one ectoparasite species, while 77 (96.25%) were carrying endoparasites. No protozoan forms were found after examination. Most prevalent endoparasite species found were Contracaecum rudolphii s. l. (72/80, 90%), followed by Pectinopygus gyroceras (33/80, 41.25%), and Profilicollis altmani (26/80, 32.5%). This is the first report of P. altmani, Baruscapillaria carbonis, Avioserpens sp., Cyathostoma (Cyathostoma) phenisci, and Eidmaniella pelucida in the Neotropic cormorant. These findings also expand the distributional range of Andracantha phalacrocoracis, Paradilepis caballeroi, Hysteromorpha triloba, and P. gyroceras to Chile.

Conserving the Amazon River Basin: The case study of the Yahuarcaca Lakes System in Colombia

Colombia is the fourth contributor to the Amazon River Basin (ARB) by surface, and the third by mean annual runoff. The Yahuarcaca Lakes System (YLS), consisting of four large interconnected water bodies situated on the floodplain of Amazon River, was identified as one of the key areas for the conservation of freshwater biodiversity in the Colombian ARB. This review aimed to provide a general overview of YLS, present its environmental and biological features, identify main ecological and health threats, and propose mitigation strategies and future research prospects. A systematic search was performed using various databases. In summary, YLS harbors significant biodiversity and provides a number of ecological services for local communities, encompassing fish and drinking water supply and utilization of the floodplain for agriculture. Ensuring its sustainability requires attention from local and international authorities, collaboration with indigenous communities and future interdisciplinary research.

On the Coronaviruses and Their Associations with the Aquatic Environment and Wastewater

The outbreak of Coronavirus Disease 2019 (COVID-19), a severe respiratory disease caused by betacoronavirus SARS-CoV-2, in 2019 that further developed into a pandemic has received an unprecedented response from the scientific community and sparked a general research interest into the biology and ecology of Coronaviridae, a family of positive-sense single-stranded RNA viruses. Aquatic environments, lakes, rivers and ponds, are important habitats for bats and birds, which are hosts for various coronavirus species and strains and which shed viral particles in their feces. It is therefore of high interest to fully explore the role that aquatic environments may play in coronavirus spread, including cross-species transmissions. Besides the respiratory tract, coronaviruses pathogenic to humans can also infect the digestive system and be subsequently defecated. Considering this, it is pivotal to understand whether wastewater can play a role in their dissemination, particularly in areas with poor sanitation. This review provides an overview of the taxonomy, molecular biology, natural reservoirs and pathogenicity of coronaviruses; outlines their potential to survive in aquatic environments and wastewater; and demonstrates their association with aquatic biota, mainly waterfowl. It also calls for further, interdisciplinary research in the field of aquatic virology to explore the potential hotspots of coronaviruses in the aquatic environment and the routes through which they may enter it.