Seroepidemiological trend of strongyloidiasis in the Bolivian Chaco (1987-2013) in the absence of disease-specific control measures.

OBJECTIVES: The prevalence of Strongyloides stercoralis infections is grossly underestimated because infections go mostly undetected, although they can persist for a lifetime due to the auto-infective cycle. In the Bolivian Chaco, the prevalence of soil-transmitted nematodes dropped dramatically in the past 25 years, but the mebendazole used for preventive chemotherapy has no effect on S. stercoralis. Meanwhile, the prevalence of intestinal protozoan infections remains unchanged. We compared S. stercoralis seroprevalence in rural communities of the Bolivian Chaco from 1987 to 2013. METHODS: Sera collected during two previous serosurveys, conducted in the Chaco region in 1987 and 2013, were tested for S. stercoralis using a commercial assay (Bordier-ELISA, Bordier Affinity Products, Switzerland). RESULTS: Overall, 355 sera were analysed, 122 from the 1987 survey and 233 from the 2013 survey. Seropositivity for S. stercoralis was significantly more prevalent in 1987 (19/122, 16% in 1987 vs. 15/233, 6% in 2013, P = 0.006), accounted for by a drop from 17% to 3% in people under 26 years of age. Multivariate analysis showed a significant association between seropositivity for S. stercoralis and age in the 2013 population (OR 1.03 for each one-year increase, 95%CI 1.00-1.05, P = 0.04), but none in 1987. CONCLUSIONS: The significant reduction in S. stercoralis seroprevalence in Bolivian Chaco cannot be explained by preventive chemotherapy or improved social-sanitary conditions. As the drop is seen in younger generations, it is consistent with little transmission occurring. However, the risk of transmission still exists, as prevalence is persistently high in older individuals, who present a potential reservoir due to the lifelong nature of S. stercoralis infections.

Resistência anti-helmíntica em pequenos ruminantes do semiárido da Paraíba, Brasil / Anthelmintic resistance in small ruminants from the semiarid of Paraíba state, Brazil

Este estudo objetivou avaliar o efeito da Ivermectina 0,08% e do Cloridrato de Levamisole 5% no controle das helmintoses gastrintestinais de ovinos e caprinos da mesorregião do Agreste do Estado da Paraíba, Nordeste do Brasil. O experimento foi desenvolvido no período de julho de 2011 a fevereiro de 2012. Foram utilizadas 28 propriedades, com animais de ambos os sexos e idades entre três e 48 meses. Em cada propriedade foram escolhidos 18 animais sem tratamento anti-helmíntico a pelo menos três meses. Os animais foram divididos em três grupos: grupo 1, tratado com Ivermectina 0,08%, via oral, em dose única de 2,5 mL/ 10 kg p. v.; grupo 2, tratado com Cloridrato de Levamisole 5%, via oral, em dose única de 1,0 mL / 10 kg p. v. e grupo 3, que não recebeu tratamento anti-helmíntico, servindo como grupo controle. Amostras fecais foram coletadas nos dias zero e dez dias após os tratamentos para realização das análises fecais. O tratamento com Cloridrato de Levamisole reduziu 86,7% e 93% a carga parasitária de caprinos e ovinos, respectivamente. Entretanto, o tratamento com Ivermectina reduziu apenas 30,9% em caprinos e 24,6% em ovinos, O helminto mais prevalente nas coproculturas foi o Haemonchus spp. Os nematódeos gastrintestinais de caprinos e ovinos do Agreste da Paraíba encontram-se altamente resistentes à Ivermectina. O Cloridrato de Levamisole ainda é efetivo em ovinos, mas já apresenta traços de resistência em caprinos(AU)

This study aimed to evaluate the effect of Ivermectine 0.08% and Levamisole Hydrochloride 5% in controlling sheep and goat gastrointestinal helminthiasis from Agreste region of Paraíba State, Northeastern Brazil. The experiment was conducted from July 2011 to February 2012 with animals of both sexes from 28 farms, aged from three to 48 months. Eighteen animals without any anthelmintic treatment for at least three months were chosen from each farm. The animals were divided into three groups: group 1, treated with Ivermectine 0.08%, orally, in a single dose of 2.5 mL/ 10 kg l. w.; group 2, treated with Levamisole Hydrochloride 5%, orally, in a single dose 1.0 mL/ 10 kg l. w. and group 3, which received no anthelmintic treatment, serving as a control group. Fecal samples were collected on zero and ten days after treatments for fecal analysis. The treatment with Levamisole Hydrochloride reduced the parasite load of goats and sheep by 86.7% and 93%, respectively, while the treatment with Ivermectine, reduced the load only by 30.9% in goats and 24.6% in sheep. The most prevalent helminth species was Haemonchus spp. The gastrointestinal nematodes of goats and sheep from Agreste of Paraíba State are highly resistant to Ivermectine. Levamisole Hydrochloride is still effective in sheep, but already shows resistance traces in goats(AU)

Resistência anti-helmíntica em pequenos ruminantes do semiárido da Paraíba, Brasil / Anthelmintic resistance in small ruminants from the semiarid of Paraíba state, Brazil

Este estudo objetivou avaliar o efeito da Ivermectina 0,08% e do Cloridrato de Levamisole 5% no controle das helmintoses gastrintestinais de ovinos e caprinos da mesorregião do Agreste do Estado da Paraíba, Nordeste do Brasil. O experimento foi desenvolvido no período de julho de 2011 a fevereiro de 2012. Foram utilizadas 28 propriedades, com animais de ambos os sexos e idades entre três e 48 meses. Em cada propriedade foram escolhidos 18 animais sem tratamento anti-helmíntico a pelo menos três meses. Os animais foram divididos em três grupos: grupo 1, tratado com Ivermectina 0,08%, via oral, em dose única de 2,5 mL/ 10 kg p. v.; grupo 2, tratado com Cloridrato de Levamisole 5%, via oral, em dose única de 1,0 mL / 10 kg p. v. e grupo 3, que não recebeu tratamento anti-helmíntico, servindo como grupo controle. Amostras fecais foram coletadas nos dias zero e dez dias após os tratamentos para realização das análises fecais. O tratamento com Cloridrato de Levamisole reduziu 86,7% e 93% a carga parasitária de caprinos e ovinos, respectivamente. Entretanto, o tratamento com Ivermectina reduziu apenas 30,9% em caprinos e 24,6% em ovinos, O helminto mais prevalente nas coproculturas foi o Haemonchus spp. Os nematódeos gastrintestinais de caprinos e ovinos do Agreste da Paraíba encontram-se altamente resistentes à Ivermectina. O Cloridrato de Levamisole ainda é efetivo em ovinos, mas já apresenta traços de resistência em caprinos

This study aimed to evaluate the effect of Ivermectine 0.08% and Levamisole Hydrochloride 5% in controlling sheep and goat gastrointestinal helminthiasis from Agreste region of Paraíba State, Northeastern Brazil. The experiment was conducted from July 2011 to February 2012 with animals of both sexes from 28 farms, aged from three to 48 months. Eighteen animals without any anthelmintic treatment for at least three months were chosen from each farm. The animals were divided into three groups: group 1, treated with Ivermectine 0.08%, orally, in a single dose of 2.5 mL/ 10 kg l. w.; group 2, treated with Levamisole Hydrochloride 5%, orally, in a single dose 1.0 mL/ 10 kg l. w. and group 3, which received no anthelmintic treatment, serving as a control group. Fecal samples were collected on zero and ten days after treatments for fecal analysis. The treatment with Levamisole Hydrochloride reduced the parasite load of goats and sheep by 86.7% and 93%, respectively, while the treatment with Ivermectine, reduced the load only by 30.9% in goats and 24.6% in sheep. The most prevalent helminth species was Haemonchus spp. The gastrointestinal nematodes of goats and sheep from Agreste of Paraíba State are highly resistant to Ivermectine. Levamisole Hydrochloride is still effective in sheep, but already shows resistance traces in goats