Abstract The Brazilian poultry industry is an outstanding national and international agribusiness sector. Among the Brazilian states, São Paulo is the largest producer of commercial eggs and the fourth largest producer and exporter of chicken meat. Alternatively, semi-intensive and/or organic poultry production have also obtained a significant share of the domestic market as a result of consumer demand. Helminths affect the performance of the birds, causing significant direct or indirect losses. The objective of the present study was to identify the main helminth species present in chickens reared in 17 municipalities of the state of São Paulo. In total, 359 adult birds were investigated. The birds were reared in different housing systems and were obtained from 69 farms in the selected regions. The birds were submitted to procedures for the detection and identification of helminth parasites, following international standards. The evaluation of the small intestine employed the Mello-Campos method (Mello & Campos, 1974), which allows better recovery of cestode scolices attached to the intestinal mucosa. Stereomicroscopy was used to evaluate the collected materials, and light microscopy was used to identify the species based on their morphological characteristics. The following helminth species were diagnosed in chickens reared in 17 municipalities of the state of São Paulo: nematodes (Ascaridia galli, Capillaria sp., Cheilospirura hamulosa, Heterakis gallinarum, Oxyspirura mansoni, and Strongyloides sp.), cestodes (Amoebotaenia cuneata, Choanotaenia infundibulum, Hymenolepis sp., Raillietina cesticillus, Raillietina echinobothrida, and Raillietina tetragona), and trematodes (Zygocotyle lunata and Postharmostomum commutatum).

The seasonality of Alphitobius diaperinus population was studied during different seasons during one year, in broiler facilities located in the center-north region of the State of São Paulo. Parasite counting was weekly carried out by the use of traps adapted from the modified model of Arends. During the experimental period, facilities were not submitted to chemical treatment, and the litter was changed between flocks. A lower number of adults and larvae was observed during autumn, with the peak registered in the summer. There was no significant difference between spring and winter averages (adults and larvae), and between spring and summer averages (adults). Average temperatures in the facilities varied from 23.4ºC (winter) to 27.1ºC (spring). The environmentally controlled systems used by the broiler industry provide an adequate habitat for A. diaperinus development. The continuous monitoring of the population of this parasite is essential for designing control strategies, and this can be accomplished by utilizing the traps used in the present experiment.

Avian cryptosporidiosis has been reported in more than 30 species of birds. To date, the species infecting birds are C. baileyi, C. galli and C. meleagridis. In this study, the morphological, clinical and molecular characteristics of a Brazilian ostrich isolate of Cryptosporidium are described. The oocysts of this Brazilian isolate are larger and more elongated than those of Cryptosporidium previously reported in ostriches, which were morphologically similar to C. meleagridis. Morphological, biological and molecular analyses demonstrated similarity of this ostrich isolate with C. baileyi, suggesting that there are at least two Cryptosporidium species infecting ostriches; one with molecular, biological and morphological characteristics related to C. baileyi, and another morphologically similar to C. meleagridis.

There are few reports concerning the epidemiology of Eimeria praecox and Eimeria mitis in Brazil. In the present experiment, the polymerase chain reaction (PCR) was used to identify these species in 156 samples of broiler chicken feces from several Brazilian states and the Federal District. Oocysts present in feces samples were purified by sodium chloride flotation followed by addition of DNAzol reagent (Invitrogen®) for extraction of genomic DNA. DNA was precipitated and stored following DNAzol reagent manufacture's instructions. The primers and PCR conditions were as described by Schnitzler et al. (1999). In the 156 field samples analyzed by PCR, 70 and 45 were positive for E. praecox and E. mitis, respectively. In this study we have shown that DNA extraction using DNAzol followed by PCR can be a useful tool in epidemiological studies, since it provides fast and reliable detection of Eimeria sp. in field samples.