Seasonal distribution of gastrointestinal nematode infections in sheep in a semiarid region, northeastern Brazil

Souza, Maria de Fátima de; Pimentel-Neto, Manoel; Pinho, André Luís Santos de; Silva, Rízia Maria da; Farias, Albeísa Cleyse Batista; Guimarães, Marcos Pezzi

doi:10.1590/s1984-29612013000300006

Cited by 9 publications

(4 citation statements)

References 18 publications

(20 reference statements)

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“…This season occurs especially during warm moist summer months, with a reduction in the prevalence of H. contortus during cold winter months (SANTIAGO et al, 1976;RAMOS et al, 2004). In contrast, in regions with year round high temperatures, the limiting factor for H. contortus transmission is the lack of moisture during prolonged periods of drought, such as those observed in Brazil's semiarid northeast (CHARLES, 1995;SOUZA et al, 2013). This seasonal trend in the prevalence and/ or intensity of infection was not observed in our experimental conditions, in which H. contortus transmission, with high worm burdens, occurred year round.…”

Section: Discussionmentioning

confidence: 99%

Gastrointestinal nematode infections in sheep raised in Botucatu, state of São Paulo, Brazil

Wilmsen

Silva

Bassetto

et al. 2014

Rev. Bras. Parasitol. Vet.

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Gastrointestinal nematode infections were evaluated in sheep raised in Botucatu, state of São Paulo, Brazil between April 2008 and March 2011. Every month, two tracer lambs grazing with a flock of sheep were exposed to natural infection with gastrointestinal nematodes for 28 consecutive days. At the end of this period, the lambs were sacrificed for worm counts. Haemonchus contortus presented 100% of prevalence. The seasons exerted no significant influence on the mean intensity of H. contortus, which ranged from 315 worms in November 2010 to 2,5205 worms in January 2011. The prevalence of Trichostrongylus colubriformis was also 100%, with the lowest mean intensity (15 worms) recorded in February 2011 and the highest (9,760 worms) in October 2009. In the case of T. colubriformis, a significant correlation coefficient was found between worm counts vs. rainfall (r = -0.32; P < 0.05). Three other nematodes species were found in tracer lambs, albeit in small numbers. Their prevalence and mean intensity (in parenthesis) were as follows: Oesophagostomum columbianum 28% (25.2), Cooperia curticei 7% (4.5) and Trichuris spp. 2% (1). In conclusion, the environmental conditions of the area proved to be highly favorable for the year-round transmission of H. contortus and T. colubriformis.Keywords: Haemonchus contortus, Trichostrongylus colubriformis, tracer lamb, nematode burden, seasonal variation. ResumoA ocorrência de infecções por nematódeos gastrintestinais foi avaliada de abril de 2008 até março de 2011em ovinos criados em Botucatu, estado de São Paulo. Todos os meses, dois cordeiros traçadores foram expostos à infecção natural por nematódeos gastrintestinais, durante 28 dias consecutivos, ao pastejar junto com um rebanho de ovelhas. Ao final desse período, os animais foram sacrificados para a identificação e quantificação dos helmintos. Haemonchus contortus apresentou prevalência de 100%. Não houve influência significativa das estações do ano na intensidade média de H. contortus, que variou de 315 vermes em novembro/2010 a 25.205 vermes em janeiro/2011. Trichostrongylus colubriformis também apresentou prevalência de 100% com a menor intensidade média (15 vermes) em fevereiro/2011 e a maior (9.760 vermes) em outubro/2009. No caso de T. colubriformis, houve correlação significativa entre as contagens de vermes x precipitação (r = -0,32; P < 0,05). Outras três espécies de nematódeos foram encontradas nos cordeiros traçadores, no entanto em pequenas quantidades, com as seguintes prevalências e intensidades médias (entre parênteses): Oesophagostomum columbianum 28% (25,2), Cooperia curticei 7% (4,5) e Trichuris spp. 2 % (1). Em conclusão, as condições ambientais da área foram muito favoráveis durante todo o ano para a transmissão de H. contortus e T. colubriformis.

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Section: Discussionmentioning

confidence: 99%

Gastrointestinal nematode infections in sheep raised in Botucatu, state of São Paulo, Brazil

Wilmsen

Silva

Bassetto

et al. 2014

Rev. Bras. Parasitol. Vet.

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“…Haemonchus contortus is one of the most abundant and prevalent gastrointestinal parasite in sheep and goats in Brazil (SOUZA et al, 2013), besides causing acute disease and high mortality in all classes of livestock. Control programs have relied heavily on the use of synthetic anthelmintics.…”

Section: Introductionmentioning

confidence: 99%

Anthelmintic activity of Cymbopogon citratus against Haemonchus contortus

Macedo

Oliveira

Ribeiro

et al. 2015

Rev. Bras. Parasitol. Vet.

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Parasitic nematodes are of major economic importance in livestock. An alternative for the control of parasites is phytotherapy. This study evaluated the efficacy of Cymbopogon citratus decoction (CcD), C. citratus essential oil (CcEo) and citral against Haemonchus contortus using in vitro egg hatch test (EHT) and larval development test (LDT) and an in vivo test using a Meriones unguiculatus (gerbil) model. The effect of 800 mg/kg CcEo was evaluated in gerbils that had been artificially infected with 5,000 third-stage H. contortus larvae. The effective concentrations required to inhibit 50% (EC50) of egg hatching were 0.46, 0.14 and 0.13 mg/mL for CcD, CcEo and citral, respectively. The EC50 values in the LDT were 5.04, 1.92 and 1.37 mg/mL for CcD, CcEo and citral, respectively. H. contortus population in the group treated with C. citratus essential oil was reduced by 38.5% (P< 0.05) in comparison to the control group. These results suggest that it may be possible to use C. citratus essential oil to control of H. contortus parasite of small ruminant.Keywords: Phytotherapy, anthelmintic, Meriones unguiculatus, in vitro, citral. ResumoO parasitismo por nematoides tem grande importância econômica no rebanho. Uma alternativa para o controle de parasitas é a fitoterapia. Este estudo avaliou a eficácia do decocto de Cymbopogon citratus (DCc), do óleo essencial de C. citratus (OECc) e do citral contra Haemonchus contortus utilizando o teste in vitro de eclosão dos ovos (TEO) e o teste de desenvolvimento larval (TDL) e um teste in vivo com modelo Meriones unguiculatus (gerbil). O efeito de 800 mg/kg de OECc foi avaliado em gerbils infectados artificialmente com 5000 larvas de terceira fase de H. contortus. As concentrações efetivas necessárias para inibir 50% (CE50) da eclosão dos ovos foram 0,46; 0,14 e 0,13 mg/mL para DCc, OECc e citral, respectivamente. Os valores da CE50 no TDL foram de 5,04; 1,92 e 1,37 mg/mL para DCc, OECc e citral, respectivamente. No grupo tratado com óleo de C. citratus a população H. contortus foi reduzida em 38,5% (P < 0,05) em comparação com o grupo controle. Estes resultados sugerem que pode ser possível a utilização de óleo essencial de C. citratus para controle de H. contortus, parasita de pequenos ruminantes.Palavras-chave: Fitoterapia, anti-helmínticos, Meriones unguiculatus, in vitro, citral.

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“…In these months, gastrointestinal nematode parasitism is higher in sheep and H. contortus represents more than 80% of the nematode population in the flock (Souza et al 2013). This condition was decisive for the choice of the experiment execution period.…”

Section: Discussionmentioning

confidence: 99%

The use of Eucalyptus staigeriana nanoemulsion for control of sheep haemonchosis

et al. 2017

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Sustainable control of gastrointestinal nematodes (GIN) in small ruminants has been based on the use of alternative methods, including targeted selective treatment, such as FAMACHA. Another GIN control alternative is the use of herbal medicines, although in many cases their use is based on empirical knowledge. Biopolymer nanoformulations has been investigated to maximize the essential oil effects against sheep gastrointestinal nematodes. The aim of the present study was to combine a Eucalyptus staigeriana essential oil nanoemulsion (EsNano) with FAMACHA as an alternative control for sheep haemonchosis. The study was performed over six months at a commercial sheep farm located in a semiarid region of Northeast Brazil. Initially, a fecal egg count reduction test (FECRT) in sheep with levamisole, ivermectin and oxfendazole in sheep was performed used to determine the most effective anthelmintic to use as the positive control. Levamisole has been selected because it showed efficacy superior to 95%. EsNano was obtained and then its physicochemical properties were characterized. The average (±SE) size of the particles in the nanoemulsion was 276.8 (±12.3) nm with bimodal distribution and polydispersity. Nine visits were performed, from April to September 2013, with an interval of 17 days. One hundred sixty-two male and female sheep were divided into three groups (n=54 each) and were treated when FAMACHA score was 3, 4, or 5: G-EsNano 250mg kg -1 EsNano; G-Lev 7.5mg kg -1 levamisole (positive control), and G-Neg was not treated (negative control). Feces from sheep were collected to quantify the number of eggs per gram of feces (epg) and to identify nematode genera. Sheep weight gain was monitored. The epg data for each group and the average sheep weight gains were analyzed by variance analysis and compared with the Tukey's test (P<0.05). Significant difference between the number of animals treated with EsNano and levamisole was not observed in any visit (P>0.05). The epg variation was similar in the G-EsNano and G-Lev groups on visits (P>0.05), except the second and fifth evaluation in the epg groups were significantly different (P<0.05). Haemonchus spp. was the most prevalent nematode. There was no significant weight gain in any of the treated groups (P<0.05). The combination of phytotherapy and FAMACHA can be an alternative to minimize the use of synthetic anthelmintics to control resistant GIN populations of small ruminants.

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Seasonal distribution of gastrointestinal nematode infections in sheep in a semiarid region, northeastern Brazil

Cited by 9 publications

References 18 publications

Gastrointestinal nematode infections in sheep raised in Botucatu, state of São Paulo, Brazil

Gastrointestinal nematode infections in sheep raised in Botucatu, state of São Paulo, Brazil

Anthelmintic activity of Cymbopogon citratus against Haemonchus contortus

The use of Eucalyptus staigeriana nanoemulsion for control of sheep haemonchosis

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