title: Case-control study of pathogens involved in piglet diarrhea.
abstract: BACKGROUND
  Diarrhea in piglets directly affects commercial swine production. The disease results from the interaction of pathogens with the host immune system and is also affected by management procedures. Several pathogenic agents such as Campylobacter spp., Clostridium perfringens, Escherichia coli, Salmonella spp., group A rotavirus (RV-A), coronaviruses (transmissible gastroenteritis virus; porcine epidemic diarrhea virus), as well as nematode and protozoan parasites, can be associated with disease cases.
  
  
  RESULTS
  All bacterial, viral, protozoan, and parasitic agents here investigated, with the exception of Salmonella spp. as well as both coronaviruses, were detected in varying proportions in piglet fecal samples, and positive animals were equally distributed between case and control groups. A statistically significant difference between case and control groups was found only for Cystoisospora suis (p = 0.034) and Eimeria spp. (p = 0.047). When co-infections were evaluated, a statistically significant difference was found only for C. perfringens β2 and C. suis (p = 0.014).
  
  
  CONCLUSIONS
  The presence of pathogens in piglets alone does not determine the occurrence of diarrhea episodes. Thus, the indiscriminate use of antibiotic and anthelminthic medication should be re-evaluated. This study also reinforces the importance of laboratory diagnosis and correct interpretation of results as well as the relevance of control and prophylactic measures.
authors.affiliation: Faculty of Animal Science and Food Engineering, University of São Paulo, São Paulo, Brazil. letticie@usp.br.
authors.forename: Vera L A
authors.initials: VL
authors.lastname: Ruiz
authors.affiliation: Biological Institute, São Paulo Agency for Agribusiness Technology, Secretary of Agriculture and Food Supply, São Paulo, Brazil. bersano@biologico.sp.gov.br.
authors.forename: Josete G
authors.initials: JG
authors.lastname: Bersano
authors.affiliation: Bacteriology Laboratory, Adolfo Lutz Institute, São Paulo, Brazil. linebio@gmail.com.
authors.forename: Aline F
authors.initials: AF
authors.lastname: Carvalho
authors.affiliation: Biological Institute, São Paulo Agency for Agribusiness Technology, Secretary of Agriculture and Food Supply, São Paulo, Brazil. catroxo@biologico.sp.gov.br.
authors.forename: Márcia H B
authors.initials: MH
authors.lastname: Catroxo
authors.affiliation: São Paulo Agency for Agribusiness Technology, Secretary of Agriculture and Food Supply, São Paulo, Brazil. danichiebao@apta.sp.gov.br.
authors.forename: Daniela P
authors.initials: DP
authors.lastname: Chiebao
authors.affiliation: School of Veterinary Medicine and Animal Science, University of São Paulo, São Paulo, Brazil. acme@usp.br.
authors.forename: Fábio
authors.initials: F
authors.lastname: Gregori
authors.affiliation: Biological Institute, São Paulo Agency for Agribusiness Technology, Secretary of Agriculture and Food Supply, São Paulo, Brazil. miyashiro@biologico.sp.gov.br.
authors.forename: Simone
authors.initials: S
authors.lastname: Miyashiro
authors.affiliation: Biological Institute, São Paulo Agency for Agribusiness Technology, Secretary of Agriculture and Food Supply, São Paulo, Brazil. nassar@biologico.sp.gov.br.
authors.forename: Alessandra F C
authors.initials: AF
authors.lastname: Nassar
authors.affiliation: Faculty of Animal Science and Food Engineering, University of São Paulo, São Paulo, Brazil. tricia@usp.br.
authors.forename: Trícia M F S
authors.initials: TM
authors.lastname: Oliveira
authors.affiliation: Biological Institute, São Paulo Agency for Agribusiness Technology, Secretary of Agriculture and Food Supply, São Paulo, Brazil. renato@biologico.sp.gov.br.
authors.forename: Renato A
authors.initials: RA
authors.lastname: Ogata
authors.affiliation: Biological Institute, São Paulo Agency for Agribusiness Technology, Secretary of Agriculture and Food Supply, São Paulo, Brazil. pinheiro@biologico.sp.gov.br.
authors.forename: Eliana P
authors.initials: EP
authors.lastname: Scarcelli
authors.affiliation: School of Veterinary Medicine and Animal Science, University of São Paulo, São Paulo, Brazil. palomatonietti@gmail.com.
authors.forename: Paloma O
authors.initials: PO
authors.lastname: Tonietti
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D002167:Campylobacter / Q000302:isolation & purification; D002169:Campylobacter Infections / Q000175:diagnosis / Q000382:microbiology / Q000662:veterinary*; D016022:Case-Control Studies; D003048:Coccidiosis / Q000175:diagnosis / Q000469:parasitology / Q000662:veterinary*; D060085:Coinfection; D017934:Coronavirus / Q000302:isolation & purification; D018352:Coronavirus Infections / Q000175:diagnosis / Q000662:veterinary* / Q000821:virology; D003967:Diarrhea / Q000382:microbiology / Q000469:parasitology / Q000662:veterinary* / Q000821:virology; D004539:Eimeria / Q000302:isolation & purification; D005243:Feces / Q000382:microbiology / Q000469:parasitology / Q000821:virology; D007549:Isospora / Q000302:isolation & purification; D021865:Isosporiasis / Q000175:diagnosis / Q000469:parasitology / Q000662:veterinary*; D012401:Rotavirus / Q000302:isolation & purification; D012400:Rotavirus Infections / Q000175:diagnosis / Q000662:veterinary* / Q000821:virology; D017183:Strongylida / Q000302:isolation & purification; D017206:Strongylida Infections / Q000175:diagnosis / Q000469:parasitology / Q000662:veterinary*; D013552:Swine; D013553:Swine Diseases / Q000175:diagnosis* / Q000382:microbiology / Q000469:parasitology / Q000821:virology