Distribution, redescription, and molecular identification of Isospora striata McQuistion et al. 1997 (Eimeriidae), from woodcreepers (Dendrocolaptidae) in South America.

Woodcreepers are passerines of the family Dendrocolaptidae, which have a high forest dependency. The current work aimed to redescribe Isospora striata McQuistion et al. 1997, from two new hosts in protected areas in Brazil, revealing new localities of parasitism, in addition to providing preliminary genotypic identifications via sequencing of the mitochondrial cytochrome c oxidase subunit 1 (COI) gene from both host species. Isospora striata has oocysts that are subspheroidal to ovoidal, 19.4 × 16.8 µm with smooth wall. Oocyst residuum is absent, but micropyle and polar granules are present. Sporocysts are ovoidal, 13.6 × 8.3 µm, with both Stieda and sub-Stieda bodies. Sporocyst residuum is present and sporozoites with refractile body, nucleus, and striations. The morphological study and the 100% similarity in sequencing of the COI gene between samples of different dendrocolaptid species confirmed the identification of a single species, supporting the identification of I. striata in the Brazilian Atlantic forest and consequently the wide distribution of this coccidian species in the Neotropical Region.

House finches with high coccidia burdens experience more severe experimental Mycoplasma gallisepticum infections.

Parasites co-infecting hosts can interact directly and indirectly to affect parasite growth and disease manifestation. We examined potential interactions between two common parasites of house finches: the bacterium Mycoplasma gallisepticum that causes conjunctivitis and the intestinal coccidian parasite Isospora sp. We quantified coccidia burdens prior to and following experimental infection with M. gallisepticum, exploiting the birds' range of natural coccidia burdens. Birds with greater baseline coccidia burdens developed higher M. gallisepticum loads and longer lasting conjunctivitis following inoculation. However, experimental inoculation with M. gallisepticum did not appear to alter coccidia shedding. Our study suggests that differences in immunocompetence or condition may predispose some finches to more severe infections with both pathogens.

The vulnerable Sporophila frontalis (Verreaux) and Haplospiza unicolor Cabanis as new hosts for Isospora sporophilae Carvalho-Filho, Meireles, Ribeiro & Lopes, 2005 (Eimeriidae) in Brazil.

Isospora sporophilae Carvalho-Filho, Meireles, Ribeiro & Lopes, 2005 was morphologically and molecularly identified from the double-collared seedeater Sporophila frontalis (Verreaux), which is categorised as 'vulnerable' by the International Union for Conservation of Nature and Natural Resources (IUCN), and from the uniform finch Haplospiza unicolor Cabanis in conserved and anthropomorphic/fragmented areas of Atlantic Forest in the southeastern Brazil. The oöcysts recovered from S. frontalis and H. unicolor had small morphological and genotypic differences that were not considered sufficient for the description of new species, but only different genotypes of I. sporophilae related to each host. This coccidian species was originally described from double-collared seedeaters Sporophila caerulescens (Vieillot) in a center screening of wild animals; therefore, this new report emphasises a potential occurrence of anthropomorphic dispersion of coccidia through illegal trade, seizures and reintroductions in the wild.

Isosporan Oocysts in the Faeces of Bank Voles (Myodes glareolus; Arvicolinae, Rodentia): Real Parasites, or Pseudoparasites?

Coccidia of the genus Isospora, their origin, taxonomy, and host specificity have been discussed for many years. The crucial point in question being the division of the genus, based on distinct evolutionary history and the presence/absence of the Stieda body, into the genera Isospora (Eimeriidae) parasitizing mainly birds and reptiles, and Cystoisospora (Sarcocystidae) parasitizing mammals. The description of the majority of Isospora species from rodents is based solely on the oocysts found in their faeces. Some of them have been described with the presence of the Stieda body, some without it, and, simultaneously, for all the described species the molecular data are entirely lacking. This study reveals the origin of isosporan oocysts found in faeces of bank voles based on morphological analyses, phylogenetic analyses, and experimental infections. Morphological analyses showed the presence of the Stieda body complex on sporocysts. Phylogenetic analyses demonstrated close phylogenetic relationships between Isospora from bank voles and avian isosporans. Experimental inoculations of bank voles with sporulated oocysts of Isospora did not result in the production of unsporulated oocysts. Hence, these organisms should be considered pseudoparasites of the bank voles/rodents (probably originating from avian Isospora species).

A review of Cystoisospora felis and C. rivolta-induced coccidiosis in cats.

Until the discovery of Toxoplasma gondii oocysts in cat feces in 1970, little was known of coccidiosis in cats. Until 1970, three coccidian parasites based on different sized oocysts were recognized, the parasite with large oocysts (∼40 µm long and called Isospora felis), medium sized oocysts (∼25 µm long, called Isospora rivolta), and small sized oocysts (14 µm or less, called Isospora bigemina) were known and they were considered not host-specific. Later, it was demonstrated that these parasites were host-specific and had also extra-intestinal stages. The Isospora bigemina turned out to be more than 25 organisms belonging to T. gondii, Hammondia spp., Sarcocystis spp., Besnoitia spp., and Neospora spp.; these subjects have been reviewed previously in detail. The present paper summarizes biology of Isospora felis, and I. rivolta (now transferred to genus Cystoisospora), including taxonomy, life cycle, diagnosis, and treatment. Re-excretion of T. gondii oocysts from chronically infected cats after superinfection with Cystoisospora felis oocysts is discussed. There are only two species of Cystoisospora species in cats, C. felis and C. rivolta; Isospora novocati and Cystoisospora frenkeli named for I. rivolta-like parasites of cats are considered synonym of C. rivolta. Clinical coccidiosis occurs more commonly in recently weaned kittens and C. felis infections are more prevalent than C. rivolta.

Isospora sagittulae McQuistion & Capparella, 1992 (Apicomplexa: Eimeriidae) from antbirds (Passeriformes: Thamnophilidae) in the Amazon and Atlantic Forest of Brazil: with notes on its distribution and dispersion in the Neotropical region.

In the current study, Isospora sagittulae McQuistion and Capparella, 1992 (Protozoa: Apicomplexa: Eimeriidae) is reported from white-shouldered fire-eyes Pyriglena leucoptera (Vieillot, 1818) in the Atlantic Forest in southeastern Brazil. To date, this coccidian species was described from antbirds in Ecuador and Brazilian Amazon. In this sense, oocysts and measurements of the description of I. sagittulae from Amazonian antbirds were required from the deposit for comparison between samples from the Amazon and Atlantic Forest. The morphology was similar in all aspects, despite the polymorphism associated with the oocyst shape. DNA sequences for the mitochondrial cytochrome c oxidase subunit 1 (cox1) locus of the oocysts had similarity of 100%. Therefore, these strong morphological, molecular, and ecological equivalences ensure the unique identification of I. sagittulae. Finally, this finding reveals the wide distribution of I. sagittulae in the Neotropical region and indicates that other antbirds in the Brazilian Cerrado should disperse I. sagittulae to the Amazon and Atlantic Forest.

Good's Syndrome-Association of the Late Onset Combined Immunodeficiency with Thymoma: Review of Literature and Case Report.

Good's syndrome, the adult onset hypogammaglobulinemia associated with thymoma has been explained about six decades ago. It generally presents with recurrent infections and several paraneoplastic syndromes including myasthenia gravis, pure red cell aplasia, connective tissue disorders, superior vena cava, Horner's syndrome, lichen planus and inflammatory bowel disease. Lack of B cell, dysfunction of T cell, CD4+ T cell lymphopenia, reversed CD4/CD8+ T cell ratio, autoantibodies against Th17 related cytokines have been respected as the pathogenesis of the immune dysregulation this syndrome. A 57-year-old man was admitted to our hospital with a history of thymectomy due to thymoma (Type A) 6 years ago. He developed weight loss and recurrent persistent diarrhea caused by isospora belli. His chest CT scan revealed bilateral bronchiectasis. His laboratory data showed hypogammaglobulinemia and he was treated by monthly IVIG with the diagnosis of good's syndrome. Nevertheless he referred again with left sided loss of vision because of CMV retinitis and he also developed nail candidiasis. Good's syndrome should be considered in every patient with a history of thymoma and recurrent infection. Immunologic evaluation of these patients including measurement of the serum level of immunoglobulin as well as B cell and T cell subgroups should be performed. Physicians must be aware and think about this entity in patients with adult onset immunodeficiency.

Characterization and Distribution of Isospora sabiai N. SP. (Apicomplexa: Eimeriidae) from Thrushes Turdus spp. (Passeriformes: Turdidae) from Brazil.

A new coccidian species (Protozoa: Apicomplexa: Isospora) is described parasitizing white-necked thrushes Turdus albicollis Vieillot, 1818; rufous-bellied thrushes Turdus rufiventris Vieillot, 1818; pale-breasted thrushes Turdus leucomelas Vieillot, 1818; and yellow-legged thrushes Turdus flavipes Vieillot, 1818 from 3 different localities in Brazil. Isospora sabiai n. sp. has oocysts that are subspherical to ellipsoidal, 20.9 × 18.6 µm, with smooth, delicate, bilayered wall, ∼1.1 µm thick. Micropyle inconspicuous or imperceptible. Oocyst residuum absent, but small polar granules rounded or comma-shaped are present. Sporocysts are elongate ellipsoidal to reniform, 16.5 × 9.2 µm. The Stieda body is knob-like. Sub-Stieda body rounded to conical, sometimes homogeneous with the Stieda body. Sporocyst residuum is present, usually as a cluster of numerous granules. Sporozoites are vermiform with 2 refractile bodies. The oocysts and sporocysts of I. sabiai n. sp. are uniform in the proportionality of width on length, but exhibited different patterns of size associated with each host species; therefore, an ecological discussion is introduced aimed at associating these morphometrical patterns of the oocysts with the habits of the different species of thrushes. This is the seventh isosporoid coccidian reported from New World turdids.

Some remarks on the distribution and dispersion of Coccidia from icterid birds in South America: Isospora guaxi n. sp. and Isospora bellicosa Upton, Stamper & Whitaker, 1995 (Apicomplexa: Eimeriidae) from the red-rumped cacique Cacicus haemorrhous (L.) (Passeriformes: Icteridae) in southeastern Brazil.

A new species of coccidian, Isospora guaxi n. sp., and Isospora bellicosa Upton, Stamper & Whitaker, 1995 (Protozoa: Apicomplexa: Eimeriidae) are recorded from red-rumped caciques Cacicus haemorrhous (L.) in the Parque Nacional do Itatiaia, Brazil. Isospora guaxi n. sp. has sub-spheroidal oöcysts, measuring on average 30.9 × 29.0 µm, with smooth, bi-layered wall c.1.9 µm thick. Micropyle and oöcyst residuum are absent, but a polar granule is present. Sporocysts are ellipsoidal, measuring on average 19.3 × 13.8 µm. Stieda body is knob-like and sub-Stieda body is prominent and compartmentalized. Sporocyst residuum is composed of scattered granules. Sporozoites are vermiform, with one refractile body and a nucleus. Isospora bellicosa has sub-spheroidal to ovoidal oöcysts, measuring on average 27.1 × 25.0 µm, with smooth, bi-layered wall c.1.5 µm thick. Micropyle and oöcyst residuum are absent, but one or two polar granules are present. Sporocysts are ellipsoidal, measuring on average 18.1 × 10.9 µm. Stieda body is knob-like and sub-Stieda body is rounded to rectangular. Sporocyst residuum is composed of a cluster of compact or diffuse granules. Sporozoites are vermiform, with one refractile body and a nucleus. Isospora bellicosa was originally described from the Peruvian meadowlark Sturnella bellicosa deFilippi, a trans-Andean icterid which is allopatric with the cis-Andean C. haemorrhous. Therefore, in conclusion, this current study reveals the dispersion of coccidia from Icteridae across the Andes Mountains, besides describing the sixth isosporoid coccidium infecting an icterid bird.

Use of ponazuril paste to treat coccidiosis in shelter-housed cats and dogs.

Cystoisospora (synonym Isospora) spp. infections are common in dogs and cats worldwide, especially in crowded or unsanitary environments. Ponazuril (toltrazuril sulfone) is a widely used oral treatment, but protocols that will produce oocyst excretion below the detection limit in shelter-housed animals have not been determined. The aim of this study was to determine the efficacy of ponazuril paste at each of three dosages (dosage 1, 50mg/kg q24 h for 3 days, dogs n=14, cats n=16; dosage 2, 50mg/kg as a single dose, dogs n=13, cats n=25; or dosage 3, 20mg/kg as a single dose, dogs n=16, cats n=23) in shelter-housed dogs (n=43) and cats (n=64) with confirmed coccidiosis. Fecal oocyst counts and identification and fecal consistency scoring was performed pre-treatment (Day 1) and again at Day 3-4 and Day 8. There were higher proportions of animals with oocyst excretion below the detection limit at both Day 3-4 and Day 8 in the dosage 1 group (dogs 92.9%, cats 87.5%) than in the other two groups (dosage 2, dogs 76.9%, cats 80.0%; dosage 3, dogs 68.8%, cats 47.8%). Animals with high fecal oocyst counts at Day 1 were significantly more likely to be infected at Day 3-4 (dogs, P<0.001; cats, P=0.013). Fecal consistency score at Day 3-4 was not significantly related to infection status (dogs, P=0.898; cats, P=0.136). Further studies are warranted to investigate a ponazuril protocol that can safely reduce fecal oocyst burdens in infected dogs and cats to levels below the detection limit. Environmental decontamination is also important to reduce the likelihood of re-infection.

A new species of Isospora (Apicomplexa: Eimeriidae) infecting the Baiuch rock gecko, Bunopus tuberculatus, in Saudi Arabia.

Isospora bors n. sp. (Apicomplexa: Eimeriidae) is described from 6 of 30 (20%) Baiuch rock gecko Bunopus tuberculatus Blanford in Saudi Arabia. Sporulated oocysts are subspheroidal to spheroidal, 18 × 16 (17-20 × 15-17) µm, with a bilayered, smooth, yellow-orange wall, without striae or micropyle. Polar body and oocyst residuum, both absent. Sporocysts are ovoidal, 10 × 7 (9-11 × 6-9) µm, with a Stieda body and sporocyst residuum. Endogenous stages developed in the cytoplasm of epithelial cells of the small intestine and above the host cell nucleus.

Opportunistic and other intestinal parasites among HIV/AIDS patients attending Gambi higher clinic in Bahir Dar city, North West Ethiopia.

OBJECTIVE: To determine the magnitude of opportunistic and non-opportunistic intestinal parasitic infections among HIV/AIDS patients in Bahir Dar. METHODS: Cross-sectional study was conducted among HIV/AIDS patients attending Gambi higher clinic from April1-May 30, 2009. Convenient sampling technique was employed to identify the study subjects and hence a total of 248 subjects were included. A pre-tested structured questionnaire was used to collect socio-demographic data of patients. Stool samples were examined by direct saline, iodine wet mount, formol-ether sedimentation concentration and modified Ziehl-Neelsen staining technique. RESULTS: Out of 248 enrolled in the study, 171(69.0%) (90 males and 81 females) were infected with one or more intestinal parasites. The highest rate of intestinal parasites were observed among HIV/AIDS patients (80.3%, 151/188), and the infection rate of HIV negative individuals was 33.3% (20/60). Cryptosporidum parvum (43.6%), Isospora belli (15.5%) and Blastocystis hominis (10.5%) were opportunistic parasites that were found only in HIV/AIDS patients. CONCLUSIONS: Opportunistic parasite infections are common health problem among HIV/AIDS patients in the study area. Therefore, early detection and treatment of these parasites are important to improve the quality of life of HIV/AIDS patients.

Influence of toltrazuril treatment on parasitological parameters and health performance of piglets in the field--an Austrian experience.

Porcine coccidiosis caused by Isospora suis is one of the leading causes of neonatal diarrhea in suckling piglets. Currently the only registered drug for metaphylaxis is toltrazuril. To evaluate the effect of treatment on piglets from 7 Austrian farms without and 8 Austrian farms with toltrazuril application we examined oocyst excretion (including determination of oocysts per gram of feces; OPG), diarrhea (fecal score FS 1-4 with 3 and 4 being diarrhea), and general health (health score HS 1-4 with 3 and 4 describing poor health). Both groups included farms with different levels of hygiene. Samples from 265 litters without treatment, comprising 1588 individual samples, and 1548 samples from 258 treated litters were taken twice (around the 14th and the 21st day of life, respectively), examined by autofluorescence and, if positive, by McMaster counting. In both groups animals had less diarrhea and lower health scores during the second sampling but the treated piglets were always significantly healthier and had less diarrhea. The percentage of weaned piglets was higher in treated animals although this was not significant (p=0.052). In the first round of sampling 17.8% of the individual samples from untreated piglets were positive for oocysts (with a maximum prevalence on the 12-15th day of life) while in the treated piglets only 0.4% shed oocysts p<0.001). At the second sampling only 2.1% of the untreated animals and none of treated piglets excreted I. suis (p=0.083). Positive animals shed up to 8 × 10(3)OPG. There was an increased risk for infected piglets to develop diarrhea (odds ratio, OR 4.73) and poor health (OR 5.05) in untreated piglets, and poor hygiene without disinfection was identified as a risk factor for poor health (OR 1.90), diarrhea (OR 1.42) and oocyst excretion (OR 1.73). The risk of poor health (OR 2.89) and diarrhea (OR 1.44) was also increased for piglets under poor hygienic conditions receiving toltrazuril, so both metaphylaxis of coccidiosis and good hygiene are necessary to effectively control neonatal diarrhea. The costs of treatment are considerably lower than the estimated financial production losses. Therefore, treatment is recommended for farms where clinical coccidiosis is diagnosed.

Keeping the clock set under the midnight sun: diurnal periodicity and synchrony of avian Isospora parasites cycle in the High Arctic.

For Isospora (Protozoa: Eimeriidae) parasites of passerine birds, diurnal periodicity of oocyst output is a well-described phenomenon. From the temporal zone to the tropics, oocyst production is correlated with the light-dark cycle, peaking in the afternoon hours. However, nothing is known about the existence of diurnal periodicity of these parasites in the birds of High Arctic environments, under permanent light during summer. We sampled free-ranging Snow Bunting (Aves: Passeriformes), on Svalbard in summer and tested oocysts output of Isospora plectrophenaxia. Here we show that under the permanent light conditions of Arctic summer in the wild, Isospora plectrophenaxia, a parasite of the Snow Bunting, still keeps the 24-h rhythm of oocyst output with the peak in the post-meridiem hours, despite the absence of diurnal periodicity in host's activity. Our findings prove the ability of avian Isospora to invoke alternative cues for synchronizing the circadian rhythms. Possible cues and adaptive significance of diurnal periodicity of parasite output in High Arctic are discussed. The maintenance of synchronization and timing of the parasite life-cycle stages is under positive selection pressure even in permanent daylight in the Arctic.

Afternoon shedding of a new species of Isospora (Apicomplexa) in the endangered Regent Honeyeater (Xanthomyza phrygia).

The Regent Honeyeater (Xanthomyza phyrigia) is an endangered Australian bird species. Breeding populations have been established at Australian zoos in support of re-introduction programmes. This species is the host of a new species of Isospora (Apicomplexa). Oocysts are spherical, 25·8 (22·5-28·75) by 23·8 (20-26·25) µm with a colourless to pale yellow smooth wall undergoing rapid exogenous sporulation, 90% sporulated oocysts in 8 h at 20°C. Each oocyst contains 1 polar granule. Sporocysts are ovoid, 18·67 (17-19) by 9·49 (9-10) µm with a flat Stieda body and spherical substieda body devoid of a hyaline body. The asexual stages and sexual phase is within the enterocytes of the duodenum and jejunum. Faeces collected in the morning (AM, n=84) and in the afternoon (PM, n=90) revealed significant diurnal periodicity in oocyst shedding; 21% (18 of 84) of the AM were positive with the mean of 499 oocysts.g-1 compared to the PM with 91% (82 of 90) bird faeces positive with the mean of 129 723 oocysts.g-1. Therefore, parasite checks for these birds should be carried out in the afternoon to obtain an accurate result. The ecological significance of the high parasite burden in captive birds requires further investigation and comparison to the wild counterparts.

Survival of Isospora suis oocysts under controlled environmental conditions.

Isospora suis is a coccidian parasite infecting piglets soon after birth. While the gross epidemiology of I. suis is well known, little knowledge exists on the ecology of the oocysts. To study the development and survival of oocysts of I. suis under controlled laboratory conditions, known numbers of oocysts ( approximately 200 in each of 4 replicates) were exposed to all combinations of 4 relative humidities (53-100% RH) and 3 temperatures (20 degrees , 25 degrees , 30 degrees C). Determination of viability was based on morphological and fluorescent properties of the oocyst as well as on the permeability of the oocyst wall characterized by inclusion/exclusion of the fluorescent dye propidium iodide. The viability of the oocysts was studied over time by fluorescence and light microscopy until <5% of the oocysts were considered to be viable. The sporulation rate increased with temperature, however, the infective sporocyst stage was reached within 24h at all temperatures, while RH did not seem to affect sporulation. Results show a rapid reduction in viable oocysts exposed to high temperatures (25 degrees C and 30 degrees C) in combination with low relative humidities (53% RH and 62% RH), at which conditions oocysts died within 24h. Viability was higher when oocysts were exposed to higher relative humidities (75% RH and 100% RH) as well as a lower temperature (20 degrees C). However, even at 75% RH the oocysts died within 24-60 h at 30 degrees C to 20 degrees C, respectively, while the most favourable condition appeared to be 100% RH and 25 degrees C at which condition the percentage of viable oocysts decreased from 100% to 17% in 96 h. The results indicate that it may be possible to reduce the infection pressure of I. suis in modern sow herds by changing the environmental conditions and/or the management within the farrowing pens, and thereby increase animal welfare without relying on the use of routine medication.

Carotenoid trade-off between parasitic resistance and sexual display: an experimental study in the blackbird (Turdus merula).

Many parasites depress the expression of the carotenoid-based colour displays of their hosts, and it has been hypothesized that animals face a trade-off in carotenoid allocation between immune functions and 'degree of ornamentation'. While numerous correlative studies suggest that parasite infection decreases the intensity of carotenoid-based colour displays, the existence of this trade-off has never been demonstrated experimentally in a host-parasite model. In this study, we used the blackbird (Turdus merula) and Isospora (an intestinal parasite) to assess whether this trade-off does indeed exist. Blackbirds were supplemented with carotenoids while simultaneously being exposed to parasites. Supplemented males circulated more carotenoids in the blood and developed more brightly coloured bills than unsupplemented males. In addition, supplementation slowed down the replication rate of parasites. Supplementation with carotenoids enabled infected birds to maintain their bill coloration, whereas birds that were infected but not supplemented showed reduced bill coloration. At the same time, infection slowed carotenoid assimilation in the blood. Overall, we demonstrated that bill colour reflects a bird's health, and that only males with a carotenoid-rich diet are capable of coping with costs associated with parasitic infection. Carotenoids are thus traded off between host physiological response to parasites and secondary sexual traits. Further investigations are required to determine the physiological mechanisms that govern this trade-off.

Isospora vanriperorum Levine, 1982 (apicomplexa: eimeriidae) in the green-winged saltator, Saltator similis Lafresnaye and D'orbigny, 1837 (passeriformes: cardinalinae) in southeastern Brazil / Isospora vanriperorum Levine, 1982 (apicomplexa: eimeriidae) no trinca-ferro Saltator similis Lafresnaye and D'orbigny, 1837 (passeriformes: cardinalinae) no sudeste do Brasil

Isospora vanriperorum from the green-winged saltator (Saltator similis) is described in Southeastern Brazil. Oocysts are spherical to subspherical, 19.4-26 by 18.3-26μm (23.1 by 22.4μm), shape index 1.04 with a single layered wall, fine, smooth and yellowish. Micropyle and residuum are absents, but one elliptical polar granule is present. Sporocysts are ovoid, 14.5-20.2 by 8.1-12.5μm (16.3 by 10.8μm), shape index 1.53 with prominent Stieda body, barely discernible substieda body and residuum centered and granulated.

Isospora vanriperorum de trinca-ferro verdadeiro (Saltator similis) é descrita no sudeste do Brasil. Os oocistos são esféricos a subesféricos medindo 19,4-26 por 18,3-26μm (23,1 por 22,4μm), índice morfométrico de 1,04 com parede única, fina, lisa e amarelada. A micrópila e o resíduo estão ausentes, mas um grânulo polar elíptico está presente. Os esporocistos são ovóides medindo 14,5-20,2 por 8,1-12,5μm (16,3 por 10,8μm), índice morfométrico de 1,53 com corpo de Stieda proeminente, corpo de substieda mal discernível e resíduo central e granular.

Isospora vanriperorum Levine, 1982 (Apicomplexa: Eimeriidae) in the green-winged saltator, Saltator similis (Passeriformes: Cardinalinae) in southeastern Brazil.

Isospora vanriperorum from the green-winged saltator (Saltator similis) is described in Southeastern Brazil. Oocysts are spherical to subspherical, 19.4-26 by 18.3-26 micro (23.1 by 22.4 micro), shape index 1.04 with a single layered wall, fine, smooth and yellowish. Micropyle and residuum are absents, but one elliptical polar granule is present. Sporocysts are ovoid, 14.5-20.2 by 8.1-12.5 micro (16.3 by 10.8 micro), shape index 1.53 with prominent Stieda body, barely discernible substieda body and residuum centered and granulated.

The relative stability of chronic Isospora sylvianthina (Protozoa: Apicomplexa) infection in blackcaps (Sylvia atricapilla): evaluation of a simplified method of estimating isosporan infection intensity in passerine birds.

Estimation of intensity of coccidia infection in wild birds is essential for the studies of the parasite impact on birds' natural populations. In this paper I propose a method for quantification of coccidia oocyst output from passerine birds applicable in field investigations because it is based on one faeces droplet per bird only. This method was checked under controlled laboratory conditions on blackcaps, chronically infected with Isospora sylvianthina, and was proved to be sensitive enough for the detection of between-individual differences in parasite load. I also show that individual variation in the intensity of isosporan infection in captive blackcaps is relatively stable in time, both in the scale of a few consecutive hours and in that of consecutive days. Hence, the study shows that, in passerine birds, single measurements of oocyst production, when collected in the proper time of day, can be used to characterise some more permanent aspects of an individual's coccidia infection status.