Prevalence of Newcastle disease virus antibodies in sera and eggs of helmeted guinea fowls (<i>Numida meleagris galeata pallas</i>) in Borno and Yobe States, Nigeria

Abstract

The seroprevalence and maternal antibody profiles to Newcastle disease virus infection of guinea fowls  were studied using haemagglutination inhibition (HI) test, in Borno and Yobe States of Nigeria. Of 822 sera  and 354 egg yolk extracts tested, 327 (39.8%) and 242 (68.4%) were positive for NDV antibodies  respectively. The seroprevalence was significantly higher (P< 0.05) in the dry (47%) than in the rainy  (32.8%) seasons. Maternal antibodies in egg yolk extract (sampled during the rainy season), were  significantly (P< 0.05) higher (68.4%) than the seroprevalence. The frequency distribution of antibody  titers were skewed with 79.8% and 63.2 % of sera and egg yolk respectively having reciprocal antibody  titres ≤ 20. The geometric mean antibody titre was higher (P< 0.05) in the dry season (3.7±2.0) than in  the rainy season (2.5 ±1.7). The geometric mean titre was also higher (P<0.05) in egg (8.9±2.5) than in  sera (3.1±1.9). These results showed that Newcastle disease virus is enzootic among guinea fowls in Borno and Yobe states, especially in the dry season. The geometric mean titer of antibodies from egg yolk (8.9)  was below the protective reciprocal titres ≥35.4, suggesting the need for control measures immediately  after hatching. In addition, birds with titers ≤ 35.4 are partially immune and may shed the virus without a clinical disease when infected thereby becoming a risk to in-contact birds.

Keywords: Egg, Guinea fowls, Maternal antibodies Newcastle disease, Seroprevalence