Cattle diseases in dairy herds in Tanzania: Farmers’ view and laboratory confirmation

Cattle diseases remain a major constraint to increasing dairy productivity in Tanzania, by killing or keeping them sick and under-producing. Recent studies report overall mortality between 12 and 14 % in smallholder dairy cattle across different regions of Tanzania. Many of these diseases can also be transmitted to people, causing illness and/or even death. Existing information on the diseases affecting dairy cattle in Tanzania and their relative importance is limited and relies either on passive reporting by poorly resourced veterinary services or on localised surveys focused on a specific well known diseases. The causes of cattle diseases remain often unknown and differential diagnosis is not conducted leading to mistreatment or ineffective treatment. Addressing this concerns a survey was conducted among cattle farmers in two regions in Tanzania using participatory techniques to collect information on disease importance supported by laboratory investigations on commonly expected cattle pathogens but also those seldom looked for but known to be important in other regions. For this purpose blood samples were collected from cattle (n=402) reported by farmers to be sick and subjected to a range of tests (ELISA) including tick borne diseases, selected zoonoses (brucellosis, Q Fever), infectious bovine rhinotracheitis, bovine viral diarrhea (BVR) and bovine respiratory syncytial virus (BRSV) among other pathogens. Biological sampling was aligned with data collection on farm and diseases management. Results indicate that diseases are common for the region. Among those most prominent were East Cost fever and Anaplasmosis (32 % each). Also important zoonoses were found (e.g. Brucellosis, 11 %). High numbers of positive tested sera were also reported for pathogens commonly not tested for (e.g. IBRV). Preliminary results suggest discrepancies between laboratory results (tested positive sera) and farmer’s perceptions on specific diseases. While for East Cost Fever farmer’s perception on disease importance confirmed laboratory results (37 % versus 32 %) we found a discrepancy for brucellosis (1 % versus 11 %), a neglected zoonoses with the potential of causing chronic, long lasting diseases in humans. Implications of farming management practices on the presence/absence of certain pathogens are currently developed and part of ongoing dissemination efforts

Genetic discontinuity between local hunter-gatherers and Europes first farmers

Following the domestication of animals and crops in the Near East some 11,000 years ago, farming reached much of Central Europe by 7,500 before present. The extent to which these early European farmers ere immigrants, or descendants of resident hunter-gatherers who had learnt farming, has been widely debated. We compare new mitochondrial DNA (mtDNA) sequences from late European hunter-gatherer skeletons with those from early farmers, and from modern Europeans. We find large genetic differences betwee all three groups that cannot be explained by population continuity alone. Most (82 %) of the ancient hunter-gatherers share mtDNA types that are relatively rare in Central Europeans today. Together, thse analyses provide persuasive evidence that the first farmers were not the descendants of local hunergatherers but immigrated into Central Europe at the onset of the Neolithic

A hepatitis B virus causes chronic infections in equids worldwide

Preclinical testing of novel therapeutics for chronic hepatitis B (CHB) requires suitable animal models. Equids host homologs of hepatitis C virus (HCV). Because coinfections of hepatitis B virus (HBV) and HCV occur in humans, we screened 2,917 specimens from equids from five continents for HBV. We discovered a distinct HBV species (Equid HBV, EqHBV) in 3.2% of donkeys and zebras by PCR and antibodies against EqHBV in 5.4% of donkeys and zebras. Molecular, histopathological, and biochemical analyses revealed that infection patterns of EqHBV resembled those of HBV in humans, including hepatotropism, moderate liver damage, evolutionary stasis, and potential horizontal virus transmission. Naturally infected donkeys showed chronic infections resembling CHB with high viral loads of up to 2.6 × 109 mean copies per milliliter serum for >6 mo and weak antibody responses. Antibodies against Equid HCV were codetected in 26.5% of donkeys seropositive for EqHBV, corroborating susceptibility to both hepatitis viruses. Deltavirus pseudotypes carrying EqHBV surface proteins were unable to infect human cells via the HBV receptor NTCP (Na+/taurocholate cotransporting polypeptide), suggesting alternative viral entry mechanisms. Both HBV and EqHBV deltavirus pseudotypes infected primary horse hepatocytes in vitro, supporting a broad host range for EqHBV among equids and suggesting that horses might be suitable for EqHBV and HBV infections in vivo. Evolutionary analyses suggested that EqHBV originated in Africa several thousand years ago, commensurate with the domestication of donkeys. In sum, EqHBV naturally infects diverse equids and mimics HBV infection patterns. Equids provide a unique opportunity for preclinical testing of novel therapeutics for CHB and to investigate HBV/ HCV interplay upon coinfection