Low prevalence of Cryptosporidium sp. and Giardia ...

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Low prevalence of Cryptosporidium sp. and Giardia sp. in marine mammals present in German waters. Grilo, M.1,2,3*, Valente, S.1, Rebelo, S.1, Gomes, L.1, ...
Low prevalence of Cryptosporidium sp. and Giardia sp. in marine mammals present in German waters 1,2,3* M. ,

1 S. ,

1 S. ,

1 L. ,

Grilo, Valente, Rebelo, Gomes, Madeira de Carvalho, 1 3 1 2 2 L. , Robalo, J. , Oliveira, M. , Siebert, U. , Lehnert, K. 1 CIISA – Centre for Interdisciplinary Research in Animal Health, Faculty of Veterinary Medicine, University of Lisbon, Lisbon, Portugal 2 Institute for Terrestrial and Aquatic Wildlife Research (ITAW), University of Veterinary Medicine Hannover, Foundation, Büsum, Germany 3 MARE-ISPA, Instituto Universitário, Lisbon, Portugal *Corresponding author: [email protected]

Introduction CRYPTOSPORIDIUM AND GIARDIA IN MARINE MAMMALS

Methods GOALS 1) PREVALENCE OF CRYPTOSPORIDIUM SP. AND GIARDIA SP. IN MARINE MAMMALS PRESENT IN GERMAN WATERS 2) CHARACTERIZATION OF ASSOCIATED LESIONS

SURVEILLANCE PREVALENCE DATA FOR NORTH & BALTIC SEAS MISSING

OUR APPROACH

MICROSCOPIC EXAMINATION (ME) 1. FAECES COLLECTION (MEAN=50 MG) + ANIMAL DATA 1.1. NECROPSY (SMALL & LARGE INTESTINES) – N=83 1.2. SEALS FIELD CATCHES (RECTAL AMPULLA) – N=8 1.3. ENVIRONMENTAL SAMPLES (SEAL SCAT) – N=6 2. FAECAL SMEAR PREPARATION 3. MODIFIED ZIEHL-NEELSEN TECHNIQUE STAINING 4. CRYPTOSPORIDIUM SP. OOCYSTS AND GIARDIA SP. CYSTS IDENTIFICATION (TYPICAL STAINING, MORPHOLOGY)

HISTOPATHOLOGICAL EXAMINATION (HPE) 1. INTESTINAL TISSUES HISTOPATHOLOGICAL RECORDS COLLECTION

STATISTICAL ANALYSIS 1. ASSOCIATION BETWEEN PREVALENCE AND SEX, AGE CATEGORY & SPECIES 1.1. MICROSCOPIC EXAMINATION (FISHER’S EXACT TEST) 1.2. HISTOPATHOLOGICAL EXAMINATION (CHI-SQUARE TEST)

Results MICROSCOPIC EXAMINATION

HISTOPATHOLOGICAL EXAMINATION

JULY 2016 – MAY 2017

JUNE 1988 – JUNE 2016

CRYPT ABSCESSES WITH DEGENERATION OF THE EPITHELIUM

PHOCA VITULINA (N=564)

(75%, 3/4)

PHOCOENA PHOCOENA (N=410) HALICHOERUS GRYPUS (N=62)

PHOCOENA PHOCOENA (N=15)

CRYPTOSPORIDIUM SP. 2.1% (2/97)

HALICHOERUS GRYPUS (N=8)

ESTIMATED TRUE PREVALENCE: 2.8%, 95% IC [0.5,9.1]

GIARDIA SP. NOT

CRYPTOSPORIDIUM SP.

DETECTED ESTIMATED TRUE PREVALENCE ME: 0%, 95% IC [0,4.9] HE: 0%, 95% IC [0,0.5]

0.4% (4/1049) ESTIMATED TRUE PREVALENCE: 0.6 % (0.2,1.3) 95% IC [0.2,1.3]

PUSA HISPIDA (N=4) BALAENOPTERA ACUROROSTRATA (N=2) BALAENOPTERA PHYSALUS (N=1) GLOBICEPHALA MELAS HYPEROODON AMPULLATUS ORCINUS ORCA

POSITIVE ANIMALS

POSITIVE ANIMALS

1. JUVENILE P. VITULINA (SYLT, NORTH SEA) + NEONATE H. GRYPUS (HELGOLAND, NS), MALES 2. CAUSE OF DEATH - PV (GREY SEAL PREDATION), HG (TRAUMA) 4. NO LESIONS IN THE INTESTINES, MILD INFECTION

1. ONLY P. VITULINA, MAINLY JUVENILES AND NEONATES, EQUAL SEX DISTRIBUTION, ORIGINATING FROM THE NORTH SEA 2. LESIONS IN THE INTESTINE, MODERATE TO SEVERE INFECTION

LYMPHOID DEPLETION & SINGLE CELL NECROSIS OF

PEYER’S PATCH (75%, 3/4)

NO SIGNIFICANT ASSOCIATIONS BETWEEN PARASITE PREVALENCE AND SEX (ME – P=0.49; HPE – P=0.42); AGE CATEGORY (ME – P=0.99; HPE – P=0.13); AND SPECIES (ME – P=0.19)

Discussion 1) APPARENT LOW PREVALENCE OF CRYPTOSPORIDIUM SP. & GIARDIA SP. IN MARINE MAMMAL POPULATIONS PRESENT IN GERMAN WATERS – DIAGNOSTIC METHOD BIAS (LOWER SENSITIVITY THAN MOLECULAR METHODS) OR ANTHROPOGENIC DRIVEN SCENARIO (LOW PREVALENCE IN SCHLESWIG-HOLSTEIN HUMAN & DOMESTIC ANIMALS)? 2) SIGNIFICANT LESIONS ASSOCIATED WITH CRYPTOSPORIDIUM SP. INFECTION – POSSIBLE HEALTH THREAT FOR MARINE MAMMAL POPULATIONS; 3) FUTURE PROSPECTS – ARE GERMAN WATERS SPATIAL CLUSTERS OF LOW PREVALENCE OF ENTERIC PROTOZOANS? WHICH FACTORS PLAY A ROLE? CAN WE DEFINE RISK AREAS FOR THE INFECTION OF ENTERIC PROTOZOANS IN MARINE MAMMALS POPULATIONS?

Acknowledgments Work was supported by CIISA - Centre for Interdisciplinary Research in Animal Health, Faculty of Veterinary Medicine, University of Lisbon [funded by Project UID/CVT/276/2013 (CIISA)] and by the Ministry of Energy, Agriculture, Environment and Rural Affairs of Schleswig-Holstein and the Nationalpark Office Wadden Sea Schleswig-Holstein (health monitoring of seals). Miguel Grilo holds a PhD fellowship (C10571K) from University of Lisbon, Portugal. Authors would like to thank volunteers involved in reporting and collecting stranded marine mammals, in particular the national park rangers and seal hunters in Schleswig-Holstein; as well as the ITAW staff responsible for conducting the marine mammal necropsies.