Evidence of the Zoonotic Transmission of Cryptosporidium among Children and Pets.

We investigated the zoonotic transmission of Cryptosporidium among the children (n = 188), dogs (n = 133), and cats (n = 55) living in 188 households. Fecal samples were examined using ELISA and confirmed via nested PCR. Coproantigens oocysts were detected in 3.7% of children, 8.3% of dogs, and 5.5% of cats. We found strong evidence of two cases of the zoonotic transmission of Cryptosporidium canis between children and dogs. Furthermore, four children and their respective pets (one dog and three cats) were infected with Cryptosporidium parvum, but we cannot exclude the hypotheses that the oocysts were transmitted from children to animals or that both hosts were infected by a shared source, such as contaminated water or food. The presence of an infected animal elevated the risk of zoonotic transmission by 129.7-fold (95% CI: 13.92-1209.68). Furthermore, sharing a bed with pets was identified as a risk factor for infection in children (OR: 9.9, 95% CI: 1.37-71.2). In conclusion, the zoonotic transmission of Cryptosporidium among children and pets cohabiting in the same household may be quite common, especially when infected animals lie or sleep on children's beds. These findings unequivocally highlight the public health concern surrounding C. canis.

Cryptosporidium proventriculi in Captive Cockatiels (Nymphicus hollandicus).

Cockatiels (Nymphicus hollandicus) are among the most commonly sold psittacines pets. The aim of this study was to evaluate the occurrence of Cryptosporidium spp. in domestic N. hollandicus and identify risk factors for this infection. We collected fecal samples from 100 domestic cockatiels in the city of Araçatuba, São Paulo, Brazil. Feces from birds of both genders and older than two months were collected. Owners were asked to complete a questionnaire to identify how they handle and care for their birds. Based on nested PCR targeting the 18S rRNA gene, the prevalence of Cryptosporidium spp. in the cockatiels sampled was 9.00%, 6.00% based on Malachite green staining, 5.00% based on modified Kinyoun straining, and 7.00% when the Malachite green was combined with Kinyoun. Applying multivariate logistic regression to test the association between Cryptosporidium proventriculi positivity and potential predictors showed that gastrointestinal alterations was a significant predictor (p < 0.01). Amplicons from five samples were sequenced successfully and showed 100% similarity with C. proventriculi. In summary, this study demonstrates the occurrence of C. proventriculi in captive cockatiels.

Use of crude, FML and rK39 antigens in ELISA to detect anti-Leishmania spp. antibodies in Felis catus.

Visceral leishmaniasis is a disease caused by Leishmania (Leishmania) chagasi and represents a serious public health problem. The dog is the main urban reservoir of the disease; however, investigations regarding the occurrence and epidemiological importance of leishmaniasis in cats have recently been initiated. This study aimed to detect cats seropositive for Leishmania spp. using different antigens. Additional studies were performed using sera from cats with Toxoplasma gondii (n=15) to evaluate cross-reactivity. Serum samples (n=113) from cats living in the town of Araçatuba, State of São Paulo, Brazil, an endemic area for human and canine visceral leishmaniasis, were tested by indirect ELISA using different antigens: crude (CAG-ELISA), fucose-mannose ligand (FML-ELISA) and K39 (rK39-ELISA). Anti-Leishmania spp. antibodies were detected in 23.0% of samples evaluated by CAG-ELISA, 13.3% by FML-ELISA and 15.9% by RK39-ELISA. Only reactive sera in all three tests were considered truly positive. No disagreement occurred among the tests (p<0.05). Serum samples seropositive for toxoplasmosis tested by CAG-ELISA were negative, but one sample (6.7%) was positive for FML-ELISA and rK39-ELISA suggesting a cross-reaction between these antigens and anti-T. gondii antibodies. These findings indicate the occurrence of feline leishmaniasis in Araçatuba. Further studies are required to clarify the role of cats in the epidemiological cycle of leishmaniasis.

Comparison between ELISA using total antigen and immunochromatography with antigen rK39 in the diagnosis of canine visceral leishmaniasis.

In this study, an enzyme-linked immunosorbent assay using crude total antigen (CTA-ELISA) and immunochromatography with antigen rK39 were compared in the diagnosis of canine visceral leishmaniasis (CVL). Fifty-two total blood samples from symptomatic dogs obtained from a location endemic for leishmaniasis and 52 blood samples from healthy dogs from a nonendemic region were tested. Polymerase chain reaction (PCR) was used to detect DNA from Leishmania spp. in both groups. Symptomatic dogs with positive PCR were considered infected by Leishmania spp. and the PCR technique was chosen as a gold standard test. The sensitivity determined for CTA-ELISA was 100%, with specificity of 91.2%, while the immunochromatographic assay with the antigen rK39 showed sensitivity of 91.5%, with specificity of 94.7%. A strong correlation was verified between CTA-ELISA and immunochromatography with antigen rK39, with a kappa coefficient of agreement of 0.88. Analysis of the results suggested that both assays presented good sensitivity and specificity for diagnosing CVL; however, immunochromatography with the antigen rK39 may be more advantageous when a fast field test is required.