Outbreak investigations and molecular characterization of foot-and-mouth disease viruses circulating in south-west Niger.

In Niger, the epidemiological situation regarding foot-and-mouth disease is unclear as many outbreaks are unreported. This study aimed (i) to identify Foot-and-mouth disease virus (FMDV) strains currently circulating in cattle herds, and (ii) to identify risk factors associated with Foot-and-mouth disease (FMD)-seropositive animals in clinical outbreaks. Epithelial tissues (n = 25) and sera (n = 227) were collected from cattle in eight districts of the south-western part of Niger. Testing of clinical material revealed the presence of FMDV serotype O that was characterized within the O/WEST AFRICA topotype. The antigenic relationship between one of the FMDV isolates from Niger (O/NGR/4/2015) and three reference vaccine strains was determined by the two-dimensional virus neutralization test (2dmVNT), revealing a close antigenic match between the field isolate from Niger and three FMDV serotype O vaccine strains. Serological analyses using a non-structural protein (NSP) test provided evidence for previous FMDV infection in 70% (158/227) of the sera tested. Multivariate logistic regression analysis revealed that only the herd composition (presence of both cattle and small ruminants) was significantly associated with FMDV seropositivity as defined by NSP-positive results (p-value = .006). Of these positive sera, subsequent testing by liquid-phase blocking ELISA (LPBE) showed that 86% (136/158) were positive for one (or more) of four FMDV serotypes (A, O, Southern African Territories (SAT) 1 and SAT 2). This study provides epidemiological information about FMD in the south-western part of Niger and highlights the complex transboundary nature of FMD in Africa. These findings may help to develop effective control and preventive strategies for FMD in Niger as well, as other countries in West Africa.

Re-emergence of foot-and-mouth disease in Botswana.

The re-emergence of foot-and-mouth disease (FMD) in Botswana is reported. The disease outbreak occurred in the Matsiloje Extension Area of Francistown veterinary district situated in the northeastern part of the country in an Office International des épízooties (OIE) recognized FMD free zone without vaccination. The disease affected cattle only and did not spillover into sheep and goats resident in the same extension area, as demonstrated by lack of seroconversion to FMD when tested. The virus isolate associated with the outbreak was identified as FMD virus; Southern African Territories (SAT) type SAT-2. The disease outbreak is discussed in relation to FMD outbreaks that have occurred previously within and outside Botswana.

Destruction of Salmonella enteritidis in poultry feed by combination of heat and propionic acid.

A factorial laboratory experiment was conducted to assess the effects of heating times of 0, 20, 40, and 80 sec at 160 F and propionic acid concentrations of 0, 0.1%, and 0.2% on reduction of Salmonella enteritidis in poultry feed with approximately 15% moisture. The results showed that after 80 sec heating time an approximately 10,000-fold reduction in living salmonella was obtained in the samples with 0.2% propionic acid. Survival in the 0.2% acid group was 2 log10 lower than in the 0.1% and control groups. This difference was statistically significant. Multivariate analysis with repeated measures showed there was no interaction between heating time and propionic acid concentration (P = 0.4113). There were overall significant effects for both acid concentration (P < 0.00001) and heating time (P < 0.0001).