Investigation of Influenza A, West Nile and Newcastle Disease Viruses in Birds from the Pantanal Wetlands of Mato Grosso, Brazil

Abstract

The Pantanal is the world's largest wetland biome with a seasonal flood pulse that attracts a great diversity of birds, many of which are migratory. Birds can be natural reservoirs Influenza A, West Nile and Newcastle Disease viruses. However, the occurrence of carriers for these viruses in the Pantanal was not verified yet. The present study evaluated the occurrence of natural infection by Influenza A, WN and ND virus of birds in the municipality of Poconé, a subregion of the Pantanal in the state of Mato Grosso, Brazil. A total of 76 birds belonging to 11 orders and 20 families were captured using mist nets. The most representative order was Passeriformes, followed by the other nine orders, which included Columbiformes, Psittaciformes, Charadriiformes and Anseriformes. The most representative family was Thamnophilidae, with 16 individuals (21.0%), followed by the family Tyrannidae with 10 individuals (7.6%) and the family Furnariidae, with eight individuals (10.5%). The bird species were identified, and cloacal and tracheal swab samples were collected. The samples were subjected to RNA extraction and tested for the presence of the three agents by real-time polymerase chain reaction (qRT-PCR). All the sampled birds were considered healthy, had no clinical sign of infection, and were tested negative for the three viruses. Based on our findings, we can conclude that Influenza, West Nile and Newcastle Disease viruses were absent from the samples in this region of the Pantanal wetlands during the period of this study.

Avian Influenza in Wild Birds from South America: Review, Implications and Perspectives

“…13,14 In comparison, studies in South America have found an overall prevalence of 0.21% in Anseriformes (range: 0.25-0.86%) and 0.32% in Charadriiformes (range: 0.21-3.80%) (Table 3). 33,[35][36][37][38][39][40][41][42][43][44] It is worth noting that Mathieu et al stands out among South American studies for having found a slightly higher AIV prevalence (3.8%), which is probably related to the fact that this study investigated gulls that had been found dead, as opposed to actively capturing healthy birds in their natural habitat. 36 The reasons as to why South American wild birds appear to have a lower prevalence of AIV are unclear, and future studies will be necessary to confirm whether this is a widespread pattern and identify possible causes, or to dismiss the possibility that this reflects differences in sample collection season or storage.…”

Surveillance of avian influenza and Newcastle disease viruses in backyard poultry raised near migratory bird sites in Mato Grosso state, Brazil

“…Viral shedding of low pathogenicity AIVs from chickens showed a peak at one to two days post-inoculation followed by rapid decline to low viral titres between three and seven days post-inoculation (16). A previous survey carried out on wild birds in the Pantanal region of Mato Grosso reported no detection of AI or ND (22).…”