Development of cross-protective Eimeria-vectored vaccines based on apical membrane antigens

Recently, the availability of protocols supporting genetic complementation of Eimeria has raised the prospect of generating transgenic parasite lines which can function as vaccine vectors, expressing and delivering heterologous proteins. Complementation with sequences encoding immunoprotective antigens from other Eimeria spp. offers an opportunity to reduce the complexity of species/strains in anticoccidial vaccines. Herein, we characterise and evaluate EtAMA1 and EtAMA2, two members of the apical membrane antigen (AMA) family of parasite surface proteins from Eimeria tenella. Both proteins are stage-regulated, and the sporozoite-specific EtAMA1 is effective at inducing partial protection against homologous challenge with E. tenella when used as a recombinant protein vaccine, whereas the merozoite-specific EtAMA2 is not. In order to test the ability of transgenic parasites to confer heterologous protection, E. tenella parasites were complemented with EmAMA1, the sporozoite-specific orthologue of EtAMA1 from E. maxima, coupled with different delivery signals to modify its trafficking and improve antigen exposure to the host immune system. Vaccination of chickens using these transgenic parasites conferred partial protection against E. maxima challenge, with levels of efficacy comparable to those obtained using recombinant protein or DNA vaccines. In the present work we provide evidence for the first known time of the ability of transgenic Eimeria to induce cross protection against different Eimeria spp. Genetically complemented Eimeria provide a powerful tool to streamline the complex multi-valent anticoccidial vaccine formulations that are currently available in the market by generating parasite lines expressing vaccine targets from multiple eimerian species.     

Molecular identification of Eimeria species in Spanish bats

This is the first study reporting the detection and molecular characterization of Eimeria in bats in Spain, specifically in 12 of 32 chiropteran species described in the Iberian Peninsula. A total of 76 faecal samples were collected from different bat roosting sites across Spanish territory. The DNA was extracted from the samples and sequenced by targeting the Eimeria SSU-rRNA gene. Two Eimeria species were detected in 29 of the 76 faecal samples (38%), and the bat-specific Eimeria rioarribaensis and rodent-specific Eimeria jerfinica were detected in 4 (5%) and 25 (33%) of the samples, respectively. This is the first report of E. rioarribaensis in the bats Rhinolophus euryale, Myotis myotis and Nyctalus lasiopterus, extending the host and geographical ranges for this bat coccidian parasite. The identification of the rodent-specific parasite species E. jerfinica in bats indicates the occurrence of this species in Spain, although its presence has not previously been reported in wild rodents in this country. Considering that most of the Eimeria spp. reported in bats were described only on the basis of morphometric data, molecular studies are required to determined which Eimeria species occur in bats, to complete the identification of these species and to clarify the phylogeny.     

Molecular epidemiology of bovine Babesia spp. and Theileria orientalis parasites in beef cattle from northern and northeastern Thailand

Beef cattle production represents the largest cattle population in Thailand. Their productivity is constrained by tick-borne diseases such as babesiosis and theileriosis. In this study, we determined the prevalence of Babesia bigemina, Babesia bovis and Theileria orientalis using polymerase chain reaction (PCR). The genetic markers that were used for detection of the above parasites were sequenced to determine identities and similarity for Babesia spp. and genetic diversity of T. orientalis. Furthermore the risk factors for the occurrence of the above protozoan parasites in beef cattle from northern and northeastern parts of Thailand were assessed. A total of 329 blood samples were collected from beef cattle in 6 provinces. The study revealed that T. orientalis was the most prevalent (30.1%) parasite in beef cattle followed by B. bigemina (13.1%) and B. bovis (5.5%). Overall, 78.7% of the cattle screened were infected with at least one of the above parasites. Co-infection with Babesia spp. and T. orientalis was 30.1%. B. bigemina and T. orientalis were the most prevalent (15.1%) co-infection although triple infection with the three parasites was observed in 3.0% of the samples. Sequencing analysis revealed that B. bigemina RAP1 gene and B. bovis SBP2 gene were conserved among the parasites from different cattle samples. Phylogenetic analysis showed that the T. orientalis MPSP gene from parasites isolated from cattle in north and northeast Thailand was classified into types 5 and 7 as reported previously. Lack of tick control program was the universal risk factor of the occurrence of Babesia spp. and T. orientalis infection in beef cattle in northern and northeastern Thailand. We therefore recommend training of farmers on appropriate tick control strategies and further research on potential vectors for T. orientalis and elucidate the effect of co-infection with Babesia spp. on the pathogenicity of T. orientalis infection on beef in northern and northeastern Thailand.     

Coccidiosis in clinically asymptomatic alpaca (Vicugna pacos) crias from the Peruvian Andes

Parasites of the genus Eimeria are involved in the neonatal diarrhea complex of alpaca (Vicugna pacos) crias, and infection by Eimeria is commonly known as coccidiosis. There are limited reports of these protozoa in clinically asymptomatic crias. In this study, fecal samples from 78 clinically asymptomatic alpaca crias were analyzed to evaluate the prevalence, parasitological load, and diversity of Eimeria species. This study was conducted in the Quenamari community located in the Peruvian Andes (Marangani, Cuzco) at 4500 m above sea level. All fecal samples were examined for parasites using the quantitative McMaster and modified Stoll techniques. Microscopic examination showed the presence of Eimeria oocysts in 68 out of the 78 samples (87.18%). Among the 78 samples we found E. lamae in 67 (85.90%), E. punoensis in 49 (62.82%), E. alpacae in 42 (53.85%), E. macusaniensis in 32 (41.03%), and E. ivitaensis in four (5.13%). Regarding parasitized crias, overall there was a mean parasitological load of 43,920 oocysts per gram of feces (OPG). Eimeria lamae had the highest parasitological load (mean 206,600 OPG). These findings could be due to environmental contamination with oocysts of different Eimeria species. Additional research is needed to determine if this burden of coccidiosis could produce subclinical impacts to the health of alpaca crias.     

Some Problems of Host and Parasite Interactions in the Coccidia*

SYNOPSIS. The current status of some concepts of host and parasite interactions in the coccidia are discussed and evaluated. It is suggested that winter coccidiosis of cattle caused by Eimeria zuernii results from activation of arrested endogenous stages in the tissues of the host. A second aspect of clinical coccidiosis is that infections are seldom monospecific, but little work has been done on infections in animals with multiple species of coccidia. Information in the literature indicates that there are interactions between species of Eimeria in concurrent infections, and it is hoped that investigators will undertake studies to define more clearly what interactions there may be. Finally, the finding that there is a genetic basis for successful transmission of Eimeria separata from rats to mice provides a tool for studying the basis of host-specificity in the coccidia.     

A Virulent Babesia bovis Strain Failed to Infect White-Tailed Deer (Odocoileus virginianus)

Wildlife are an important component in the vector-host-pathogen triangle of livestock diseases, as they maintain biological vectors that transmit pathogens and can serve as reservoirs for such infectious pathogens. Babesia bovis is a tick-borne pathogen, vectored by cattle fever ticks, Rhipicephalus spp., that can cause up to 90% mortality in naive adult cattle. While cattle are the primary host for cattle fever ticks, wild and exotic ungulates, including white-tailed deer (WTD), are known to be viable alternative hosts. The presence of cattle fever tick populations resistant to acaricides raises concerns regarding the possibility of these alternative hosts introducing tick-borne babesial parasites into areas free of infection. Understanding the B. bovis reservoir competence of these alternative hosts is critical to mitigating the risk of introduction. In this study, we tested the hypothesis that WTD are susceptible to infection with a B. bovis strain lethal to cattle. Two groups of deer were inoculated intravenously with either B. bovis blood stabilate or a larval extract supernatant containing sporozoites from infected R. microplus larvae. The collective data demonstrated that WTD are neither a transient host nor reservoir of B. bovis. This conclusion is supported by the failure of B. bovis to establish an infection in deer regardless of inoculum. Although specific antibody was detected for a short period in the WTD, the PCR results were consistently negative at multiple time points throughout the experiment and blood from WTD that had been exposed to parasite, transferred into naïve recipient susceptible calves, failed to establish infection. In contrast, naïve steers inoculated intravenously with either B. bovis blood stabilate or the larval extract supernatant containing sporozoites rapidly succumbed to disease. These findings provide evidence that WTD are not an epidemiological component in the maintenance of B. bovis infectivity to livestock.     

Gastrointestinal parasitic infections in intensive dairy cattle breeding: Update on the epidemiology and associated risk factors in northern Italy

Parasitic infections such as Strongylida and Eimeria still represent a major health problem of dairy cattle impacting their health, welfare, and productivity. In view of the scarcity of data on risk factors contributing to the spread of parasitic infections in cattle breeding, an epidemiological study in intensive dairy farms in northern Italy was planned. 495 animals (lactating and dry cows, heifers, and calves) from 19 farms were enrolled in the study. Individual fecal samples were analyzed by a quantitative copromicroscopic analysis to detect the number of Strongylida eggs or Eimeria oocysts per gram of faeces (EPG/OPG). Data concerning management, sanitary and biosecurity measures were collected using a questionnaire; a management measures score (MMS) was also calculated. The possible influence of risk factors on Strongylida and Eimeria was thus assessed by statistical analysis using generalized linear mixed models (GLMMs).Eimeria spp. was the most frequently detected parasitic taxon (herd and individual prevalence: 89.5% and 46.2%, respectively), followed by Strongylida (herd and individual prevalence: 63.1% and 16.6%, respectively). The presence of Strongylida resulted associated to the productive category (p-value = 0.028), with heifers and dry cows at higher risk of infection than lactating cows and calves, and to the MMS (p-value = 0.007). Higher prevalence values were recorded in farms with intermediate or low MMS compared to those with optimal MMS. As regard Eimeria infection, a greater effect of MMS on OPG was recorded in calves when compared to those recorded in heifers (OR = 0.228, p-value = 0.003) and dry cows (OR = 0.241, p-value = 0.009).Gastrointestinal parasitic infections still remain an underestimated problem in intensive dairy cattle breeding. MMS may help in the choice of strategies aimed at minimizing the impact of parasites on animal health, thus improving the productivity of the entire herd.     

Identification of a novel species of Eimeria Schneider, 1875 from the woylie,Bettongia penicillata Gray (Diprotodontia: Potoroidae) and the genetic characterisation of three Eimeria spp. from other potoroid marsupials

Faecal samples (n = 1,093) collected from the woylie Bettongia penicillata Gray, in south-western Australia were examined for the presence of coccidian parasites. Eimeria sp. oöcysts were detected in 15.2% of samples. Faecal samples obtained from the eastern bettong Bettongia gaimardi (Desmarest) (n = 4) and long-nosed potoroo Potorous tridactylus (Kerr) (n = 12) in Tasmania, were also screened for the presence of Eimeria spp. (prevalence 50% and 41.7%, respectively). Morphological and genetic comparison with other known species of Eimeria indicates that the material identified in woylies is novel. This study aimed to (i) morphologically describe and genetically characterise Eimeria woyliei n. sp. found in woylies; and (ii) genetically characterise Eimeria gaimardi Barker, O’Callaghan & Beveridge, 1988, Eimeria potoroi Barker, O’Callaghan & Beveridge, 1988, and Eimeria mundayi Barker, O’Callaghan & Beveridge, 1988, from other potoroid marsupials. Molecular phylogenetic analyses conducted at the 18S rDNA and mitochondrial cytochrome c oxidase subunit 1 (cox1) loci revealed that E. woyliei n. sp. was most closely related to Eimeria setonicis Barker, O’Callaghan & Beveridge, 1988, at the 18S rDNA locus, and Eimeria trichosuri O’Callaghan & O’Donoghue, 2001, at the cox1 locus. Eimeria woyliei n. sp. is the sixth species of Eimeria to be formally described from potoroid marsupials.

     

Genetic and biological characterisation of three cryptic Eimeria operational taxonomic units that infect chickens (Gallus gallus domesticus)

More than 68 billion chickens were produced globally in 2018, emphasising their major contribution to the production of protein for human consumption and the importance of their pathogens. Protozoan Eimeria spp. are the most economically significant parasites of chickens, incurring global costs of more than UK £10.4 billion per annum. Seven Eimeria spp. have long been recognised to infect chickens, with three additional cryptic operational taxonomic units (OTUs) first described more than 10 years ago. As the world’s farmers attempt to reduce reliance on routine use of antimicrobials in livestock production, replacing drugs that target a wide range of microbes with precise species- and sometimes strain-specific vaccines, the breakthrough of cryptic genetic types can pose serious problems. Consideration of biological characteristics including oocyst morphology, pathology caused during infection and pre-patent periods, combined with gene-coding sequences predicted from draft genome sequence assemblies, suggest that all three of these cryptic Eimeria OTUs possess sufficient genetic and biological diversity to be considered as new and distinct species. The ability of these OTUs to compromise chicken bodyweight gain and escape immunity induced by current commercially available anticoccidial vaccines indicates that they could pose a notable threat to chicken health, welfare, and productivity. We suggest the names Eimeria lata n. sp., Eimeria nagambie n. sp. and Eimeria zaria n. sp. for OTUs x, y and z, respectively, reflecting their appearance (x) or the origins of the first isolates of these novel species (y, z).     

Bovine babesiosis: Cattle protected in the field with a frozen vaccine containing Babesia bovis and Babesia bigemina cultured in vitro with a serum-free medium

An attenuated live vaccine containing Babesia bovis and B. bigemina cultured in vitro with a serum-free medium was assessed for its clinical protection conferred of naïve cattle, under natural tick-challenge in a high endemicity zone to Babesia spp. Three groups of six animals were treated as follows: group I (GI) received a vaccine derived from parasites cultured with a free-serum medium; group II (GII) were immunized with the standard vaccine, with parasites cultured in a medium supplemented with 40% (v/v) bovine serum; and a control group (GIII) inoculated with non-infected bovine erythrocytes. Inocula were administered by IM route. Experimental animals were kept during 23 days after vaccination in a cattle farm free of ticks and Babesia spp. Thereafter, cattle were moved to a high endemicity farm for natural exposure to Babesia spp. transmitted by Rhipicephalus microplus ticks. Protection against clinical babesiosis was observed in bovines belonging to GI (100%) and GII (83.33%), while the control animals (GIII) were not protected, and showed severe clinical signs, closely related to babesiosis, were observed for at least three consecutive days during the challenge. These were fever, anemia, which were measured simultaneously, and circulating parasites were detected by optic light microscopy. All cattle showed B. bovis and B. bigemina in stained blood films during the challenge; B. bovis antibody titers were higher than those to B. bigemina in GI and GII, and lower titers were determined in GIII. The protective capacity of the vaccine derived from B. bovis and B. bigemina cultured in vitro in a serum-free medium was demonstrated.     

Concurrence of Eimeria and helminth parasitic infections in West African Dwarf kids in Ghana

The sequence of appearance of Eimeria and helminths, in 20 West African Dwarf kids from birth and the pattern of oocyst and strongyle worm egg output for 1.5 years are described. Eimeria oocysts appeared early about 20 days after birth and oocyst output in some kids reached 2.7 million oocysts per gram (opg) of faeces about 39 days after birth and showed a group mean oocyst output of 443,540 opg in the second month but this declined further to 23,840 opg after 5.5 months. Eimeria arloingi (20.50%), Eimeria ninakohlyakimovae (17.02%), Eimeria alijevi (15.07%), Eimeria caprina (12.65%), Eimeria jolchijevi (11.42%), Eimeria apsheronica (8.70%), Eimeria pallida (5.31%), Eimeria caprovina (3.29%), Eimeria hirci (3.20%) and Eimeria christenseni (2.84%) were seen in a descending order of prevalence. Strongyle worm ova were seen 53 days after birth and peaked soon after the fall in Eimeria oocyst output but thereafter fluctuated. The eggs of cestode, Moniezia spp. appeared later but was transient. Both oocyst and worm egg output declined and were almost absent when the kids were about 1 year old. Faecal larval cultures were made and the L₃s identified with the dominant ones being Haemonchus spp. and Trichostrongylus spp. Sixty percent of the kids in this study died when they were 7 months old and a total of 70% of the kids had died before they were 1 year old.     

Molecular and phylogenetic characterizations of an Eimeria krijgsmanni Yakimoff & Gouseff, 1938 (Apicomplexa: Eimeriidae) mouse intestinal protozoan parasite by partial 18S ribosomal RNA gene sequence analysis

Previously, we characterized an undocumented strain of Eimeria krijgsmanni by morphological and biological features. Here, we present a detailed molecular phylogenetic analysis of this organism. Namely, 18S ribosomal RNA gene (rDNA) sequences of E. krijgsmanni were analyzed to incorporate this species into a comprehensive Eimeria phylogeny. As a result, partial 18S rDNA sequence from E. krijgsmanni was successfully determined, and two different types, Type A and Type B, that differed by 1 base pair were identified. E. krijgsmanni was originally isolated from a single oocyst, and thus the result show that the two types might have allelic sequence heterogeneity in the 18S rDNA. Based on phylogenetic analyses, the two types of E. krijgsmanni 18S rDNA formed one of two clades among murine Eimeria spp.; these Eimeria clades reflected morphological similarity among the Eimeria spp. This is the third molecular phylogenetic characterization of a murine Eimeria spp. in addition to E. falciformis and E. papillata.     

Transfection of Eimeria and Toxoplasma using heterologous regulatory sequences

Eimeriatenella and Toxoplasmagondii are Apicomplexan protozoa and share many similarities in biology and genomics. While the latter parasites are easily cultured in vitro and genetically manipulated, many Eimeria species are difficult to grow in vitro. We hypothesised that molecular tools for the genetic manipulation of T. gondii could be applied to the study of Eimeria parasites. Here we show that three different promoter sequences originating from E. tenella could function effectively not only in other species of the Eimeria genus (histone H4) but also in T. gondii (histone H4, actin and tubulin). Similarly, promoters of the “housekeeping” gene (tubulin) and differentially regulated gene (surface antigen gene, sag1) of T. gondii were effective in driving the expression of the yellow fluorescent protein (YFP) maker gene in E. tenella. The transfection efficiency with heterologous regulatory sequences was similar to that with homologous promoters; while the promoter strength of heterologous vectors is slightly weaker than the homologous vectors in both E. tenella and T. gondii. The results suggest that 5′ regulatory sequences are functionally conserved not only among the Eimeria species, but also between T. gondii and E. tenella, and that T. gondii could be used as a novel transfection check system for Eimeria-rooted vectors, accelerating the development of reverse genetics in Eimeria spp.     

Stable transfection of Eimeria tenella: constitutive expression of the YFP-YFP molecule throughout the life cycle

The obligate intracellular apicomplexan parasite Eimeria tenella, one of seven species of Eimeria that infect chickens, elicits protective cell-mediated immunity against challenge infection. For this reason, recombinant E. tenella parasites could be utilised as an effective vaccine vehicle for expressing foreign antigens and inducing immunity against heterologous intracellular microbes. A stable line of E. tenella expressing foreign genes is a prerequisite, and in this work an in vivo stable transfection system has been developed for this parasite using restriction enzyme-mediated integration (REMI). Two transgenic populations of E. tenella have been obtained that express YFP-YFP constitutively throughout the parasite life cycle. Southern blotting and plasmid rescue analyses show that the introduced exogenous DNA was integrated at random into the parasite genome. Although the life cycle of the transgenic populations was delayed by at least 12 h and the output of oocysts was reduced 4-fold relative to the parental BJ strain of E. tenella, the transgenic parasites were sufficiently immunogenic to protect chickens against challenge with either transgenic or parental parasites. These results are encouraging for the development of transgenic E. tenella as a vaccine vector and for more detailed investigation of the biology of the genus Eimeria.     

Molecular Surveillance of Cryptosporidium spp., Giardia duodenalis, and Enterocytozoon bieneusi by Genotyping and Subtyping Parasites in Wastewater

Background

Despite their wide occurrence, cryptosporidiosis and giardiasis are considered neglected diseases by the World Health Organization. The epidemiology of these diseases and microsporidiosis in humans in developing countries is poorly understood. The high concentration of pathogens in raw sewage makes the characterization of the transmission of these pathogens simple through the genotype and subtype analysis of a small number of samples.

Methodology/Principal Findings

The distribution of genotypes and subtypes of Cryptosporidium spp., Giardia duodenalis, and Enterocytozoon bieneusi in 386 samples of combined sewer systems from Shanghai, Nanjing and Wuhan and the sewer system in Qingdao in China was determined using PCR-sequencing tools. Eimeria spp. were also genotyped to assess the contribution of domestic animals to Cryptosporidium spp., G. duodenalis, and E. bieneusi in wastewater. The high occurrence of Cryptosporidium spp. (56.2%), G. duodenalis (82.6%), E. bieneusi (87.6%), and Eimeria/Cyclospora (80.3%) made the source attribution possible. As expected, several human-pathogenic species/genotypes, including Cryptosporidium hominis, Cryptosporidium meleagridis, G. duodenalis sub-assemblage A-II, and E. bieneusi genotype D, were the dominant parasites in wastewater. In addition to humans, the common presence of Cryptosporidium spp. and Eimeria spp. from rodents indicated that rodents might have contributed to the occurrence of E. bieneusi genotype D in samples. Likewise, the finding of Eimeria spp. and Cryptosporidium baileyi from birds indicated that C. meleagridis might be of both human and bird origins.

Conclusions/Significance

The distribution of Cryptosporidium species, G. duodenalis genotypes and subtypes, and E. bieneusi genotypes in urban wastewater indicates that anthroponotic transmission appeared to be important in epidemiology of cryptosporidiosis, giardiasis, and microsporidiosis in the study areas. The finding of different distributions of subtypes between Shanghai and Wuhan was indicative of possible differences in the source of C. hominis among different areas in China.     

Using genetic analysis to determine the distribution,prevalence and diversity of Eimeria species in pest rabbits (Oryctolagus cuniculus) in Australia

To genetically assess the Australian distribution and frequency of Eimeria species in wild rabbits, with a primary focus on Eimeria intestinalis and Eimeria flavescens as possible additional agents of rabbit biocontrol, the distal colon and faecal samples from wild rabbits sourced from 26 Australian locations with mean annual rainfalls of between 252 mm and 925 mm were analysed using amplicon sequencing of the ITS1 region. Contrary to previous microscopy studies which had only detected E. flavescens on mainland Australia at Wellstead in south-west Western Australia, we detected this species at all 23 effectively sampled sites. The more pathogenic E. intestinalis was only found at 52.2% of sites. Three unique Eimeria genotypes were detected that did not align to the 11 published sequences using a pairwise-match threshold of 90%, and may represent unsequenced known species or novel species. One genotype we termed E. Au19SH and was detected at 20 sites, E. Au19CO was detected at eight sites, and E. Au19CN was detected in one rabbit at Crows Nest (Qld). Site diversity ranged from only five Eimeria species at Boboyan (ACT) to 13 unique sequences at Cargo (NSW). Eimeria diversity in individual rabbits ranged from 11 unique sequences in a rabbit at Wellstead (WA) and a rabbit at Cargo (NSW), to one in 17 rabbits and zero in six rabbits. The three rabbit age classes averaged 4.3 Eimeria species per rabbit. No relationship was found between the number of Eimeria species detected and mean annual rainfall. As Eimeria species were found to be fairly ubiquitous at most sites they appear to be an unlikely additional candidate to assist the control of pest rabbits in Australia.     

Babesia rodhaini, Babesia bovis, and Babesia bigemina: analysis and sorting of red cells from infected mouse or calf blood by flow fluorimetry using 33258 Hoechst.

The DNA of Babesia spp. parasites within host intact red blood cells was labeled using the fluorescent bisbenzimidazole dye 33258 Hoechst. The labeled cells were sorted on a fluorescence activated cell sorter on the basis of cell fluorescence (proportional to DNA content) and the intensity of light scattered from the cells at low angles (related to cell size). The optimal conditions for dye uptake were established for the murine parasite Babesia rodhaini and the bovine parasites B. bovis and B. bigemina. Uninfected cells were nonfluorescent after incubation with the dye and could be completely separated from infected fluorescent cells. The fluorescence of cells infected with B. rodhaini was proportional to the number of parasite nuclei per cell. With saturation levels of dye, samples infected with B. bovis or B. bigemina in which erythrocytes contained one or two parasites, both exhibited only one fluorescent cell peak. Cell sorting did not eliminate the infectivity of B. rodhaini. The method may be used to separate populations of uninfected blood cells and cells infected with Babesia spp. for biochemical and immunochemical experiments.     

Correlation between intestinal health and coccidiosis prevalence in broilers in Brazilian agroindustries

Coccidiosis is caused by protozoa of the genus Eimeria. These are intracellular parasites of enterocytes that rupture the host cell, causing lesions in the intestinal mucosa. The lesions caused by Eimeria reduce nutrient absorption capacity, negatively affecting productive gains in broilers, and representing a gateway for other enteropathogens. The objective of this study was to analyze the correlation between lesions caused by Eimeria and the prevalence of coccidiosis and other alterations found in the gastrointestinal tracts of broilers produced in Brazil from 2017 to 2018. Intestinal health evaluations were performed in 32 integrations (farm) of broilers in Brazil, totaling 726 birds analyzed between the ages of 22 and 40 days. Necropsied chickens were collected at three different points, with at least three birds per shed. We analyzed the following changes in the gastrointestinal tract: presence of cellular desquamation, fluid and mucus excess, ingestion of bedding, small and large intestine lesion, food passage, altered tone, “Turkish towel” lesions, worm infection, enteritis and gizzard erosion. The definition of macroscopic lesion scores caused by Eimeria acervulina, Eimeria maxima, Eimeria tenella followed a specific methodology. Mucosal oocyst counts for E. maxima (E. maxima micro) was performed using an optical microscope with a magnification of 100×. We found that the species E. acervulina had the highest prevalence (5.5%). With respect to E. acervulina, a positive correlation was observed with cellular desquamation, bedding ingestion and passage of food. The second highest prevalence was E. maxima (average of 4%), showing positive correlations with cellular desquamation, fluid excess, bed ingestion, feed passage and E. acervulina. E. tenella represented the lowest prevalence (0.8%) among the species of Eimeria analyzed, showing a positive correlation with altered intestinal tone. On microscopic evaluation, E. maxima was present in 45% of mucosa scrapings, representing subclinical coccidiosis of 1125% (11.25-fold) greater than the rate of clinical coccidiosis. Regarding other alterations that were visualized in the gastrointestinal tract, we have recorded the incidence of altered intestinal tone (0.1%), worm infection (0.4%), small intestine (0.8%), enteritis (1%), duodenitis (1.5%), “Turkish towel” lesions (3.3%), excess fluid (4.5%), bed ingestion (6.9%), excess mucus (8.4%), food passage (10.3%), cellular desquamation (11%) and gizzard erosion (13.4%). We conclude that monitoring is of paramount importance to understand the intestinal health status of poultry lots. Microscopic E. maxima is present in 45%. We identified factors that correlate with reduction in intestinal health, impairing zoo-economic performance.