Assessment of milk handling practices and bacterial contaminations along the dairy value chain in Lushoto and Handeni districts, Tanzania

Contaminated milk is responsible for up to 90% of all dairy-related diseases of humans. A cross sectional study was carried out in Lushoto and Handeni districts of Tanga, Tanzania to determine the milk handling practices, bacterial contamination and selected milk-borne zoonotic pathogens along the dairy value chain. A total of 93 respondents were interviewed and 184 milk and milk product samples were collected. Laboratory analysis of total and coliform plate counts, detection of Escherichia coli O157:H7 and Brucella abortus using polymerase chain reaction (PCR) were done. Results showed that, most farmers (57 %) milked their cows under unhygienic conditions. More than 60% of farmers did not clean their hands, wash cow teats and clean animal houses before milking. The majority (92.1%) of farmers were not trained on livestock keeping and milk handling. Although the mean TPC was within the East African Community (EAC) standards, general counts ranged between 3.3 to 5.8 log10. Eighty seven and 93% of milk from farmers and vendors, respectively, did not meet the TPC EAC standards. All the collected milk did not meet the CPC EAC standards, indicating contamination of milk with coliforms. PCR analyses did not detect E. coli O157:H7 in all the tested samples while B. abortus was detected in 37 out of 87 samples tested. It was concluded that unhygienic practices of milking and post-harvest handling along the dairy value chain possibly contributed to microbial contamination of milk. Detection of B. abortus in milk is of public health significance due to its zoonotic potential. It is recommended that veterinary/extension services be provided to livestock farmers on proper animal husbandry and control of zoonotic animal diseases. Public education should be given to all stakeholders in dairy industry on milking and post harvest handling of milk to curtail the likely losses due to rejection of spoiled milk and milk-borne pathogens resulting from contamination of milk.German Federal Ministry for Economic Cooperation and Development, through the Safe Food, Fair Food projec

Assessment of milk handling practices and bacterial contaminations along the dairy value chain in Lushoto and Handeni districts, Tanzania

Contaminated milk is responsible for up to 90% of all dairy-related diseases of humans. A cross sectional study was carried out in Lushoto and Handeni districts of Tanga, Tanzania to determine the milk handling practices, bacterial contamination and selected milk-borne zoonotic pathogens along the dairy value chain. A total of 93 respondents were interviewed and 184 milk and milk product samples were collected. Laboratory analysis of total and coliform plate counts, detection of Escherichia coli O157:H7 and Brucella abortus using polymerase chain reaction (PCR) were done. Results showed that, most farmers (57 %) milked their cows under unhygienic conditions. More than 60% of farmers did not clean their hands, wash cow teats and clean animal houses before milking. The majority (92.1%) of farmers were not trained on livestock keeping and milk handling. Although the mean TPC was within the East African Community (EAC) standards, general counts ranged between 3.3 to 5.8 log10. Eighty seven and 93% of milk from farmers and vendors, respectively, did not meet the TPC EAC standards. All the collected milk did not meet the CPC EAC standards, indicating contamination of milk with coliforms. PCR analyses did not detect E. coli O157:H7 in all the tested samples while B. abortus was detected in 37 out of 87 samples tested. It was concluded that unhygienic practices of milking and post-harvest handling along the dairy value chain possibly contributed to microbial contamination of milk. Detection of B. abortus in milk is of public health significance due to its zoonotic potential. It is recommended that veterinary/extension services be provided to livestock farmers on proper animal husbandry and control of zoonotic animal diseases. Public education should be given to all stakeholders in dairy industry on milking and post harvest handling of milk to curtail the likely losses due to rejection of spoiled milk and milk-borne pathogens resulting from contamination of milk.German Federal Ministry for Economic Cooperation and Development, through the Safe Food, Fair Food projec

Mosquito-borne viruses circulating in Kinshasa, Democratic Republic of the Congo

Background: Diseases caused by mosquito-borne viruses are among the most important emerging diseases that threaten human and animal health, particularly in Africa. However, little attention has been paid to these diseases in the Democratic Republic of the Congo (DRC). The present cross-sectional study was undertaken between March and May 2014 to investigate the presence of mosquito-borne viruses in mosquitoes collected from five municipalities of Kinshasa, DRC. Methods: Mosquitoes were collected using BG-Sentinel traps and battery-powered aspirators. Female mosquitoes were pooled according to their genera and sampling locations, preserved in RNAlater, and later screened for viruses using reverse transcription PCR (RT-PCR) assays. Results: A total of 2922 mosquitoes were collected and 29 pools of female mosquitoes, containing approximately 30 mosquitoes each, were tested. Twelve of the 29 (41.4%) mosquito pools were found to be infected with at least one arbovirus, with eight (27.5%) pools positive for Alphavirus, nine (31%) for Flavivirus, and five (17.2%) for Bunyaviridae. Chikungunya, o’nyong’nyong, and Rift valley fever viruses were detected. Conclusions: The present study shows that mosquitoes in Kinshasa carry mosquito-borne viruses that may have serious public health implications. Further investigations on the presence of mosquito-borne viruses in the human and livestock populations of Kinshasa and DRC are recommended

Molecular differentiation of the African yellow fever vector Aedes bromeliae (Diptera: Culicidae) from its sympatric non-vector sister species Aedes lilii

INTRODUCTION:Yellow fever continues to be a problem in sub-Saharan Africa with repeated epidemics occurring. The mosquito Aedes bromeliae is a major vector of yellow fever, but it cannot be readily differentiated from its non-vector zoophilic sister species Ae. lilii using morphological characters. Genetic differences have been reported between anthropophilic Ae. bromeliae and zoophilic Ae. lilii and between forest and domestic populations. However, due to the application of different molecular markers and non-overlapping populations employed in previous studies, interpretation of species delimitation is unclear. METHODOLOGY/PRINCIPLE FINDINGS:DNA sequences were generated from specimens of Ae. simpsoni s.l. from the Republic of Benin, Tanzania and Uganda for two nuclear genes apolipophorin 2 (apoLp2) and cytochrome p450 (CYPJ92), the ribosomal internal transcribed spacer region (ITS) and the mitochondrial cytochrome c oxidase (COI) barcoding region. Nuclear genes apoLp2 and CYPJ92 were unable to differentiate between species Ae. bromeliae and Ae. lilii due to ancestral lineage sorting, while ITS sequence data provided clear topological separation on a phylogeny. The standard COI barcoding region was shown to be subject to species introgression and unable to clearly distinguish the two taxa. Here we present a reliable direct PCR-based method for differentiation of the vector species Ae. bromeliae from its isomorphic, sympatric and non-biomedically important sister taxon, Ae. lilii, based on the ITS region. Using molecular species verification, we describe novel immature habitats for Ae. lilii and report both sympatric and allopatric populations. Whereas only Ae. lilii is found in the Republic of Benin and only Ae. bromeliae in Tanzania, both species are sympatric in Uganda. CONCLUSIONS/SIGNIFICANCE:Our accurate identification method will allow informed distribution and detailed ecological studies that will facilitate assessment of arboviral disease risk and development of future targeted vector control

The number of individuals (n = 110) identified from sampled locations using our PCR mediated identification method.

<p>The number of individuals (n = 110) identified from sampled locations using our PCR mediated identification method.</p

Electrophoresis gel for primer sets (A) BRO-F and BRO-R and (B) LIL-F and LIL-R.

<p>PCR products were run with Hyperladder IV (HyIV) and a negative control (NgC).</p

Neighbour joining tree of <i>CYPJ92</i> sequence data with labels coloured according to <i>ITS</i>-based species designation.

<p>Red labels represent <i>Ae</i>. <i>bromeliae</i> while blue labels are <i>Ae</i>. <i>lilii</i>. Sequences from Walter <i>et al</i>. [<a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0004250#pntd.0004250.ref028" target="_blank">28</a>] (*) and <i>Ae</i>. <i>aegypti</i> outgroups (~) from Brown <i>et al</i>. [<a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0004250#pntd.0004250.ref047" target="_blank">47</a>] are annotated. Bootstrap support values for branches above 55% are shown.</p

Map of sampling points for <i>Ae</i>. <i>bromeliae</i> (red circles) and <i>Ae</i>. <i>lilii</i> (blue circles) used in the current study including samples from Mukwaya <i>et al</i>. [27] and Le Goff <i>et al</i>. [43].

<p>Also mapped are the previously described sampling points for <i>Ae</i>. <i>bromeliae</i> (red triangles), <i>Ae</i>. <i>lilii</i> (blue triangles) and <i>Ae</i>. <i>simpsoni</i> s.s (green triangles) based on morphological identification, taken from Huang [<a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0004250#pntd.0004250.ref023" target="_blank">23</a>]. The map was created in QGIS (QGIS Development Team) made with Natural Earth.</p

Neighbour joining tree of <i>ITS</i> sequence data with labels coloured according to species designation based on <i>ITS</i> as in Mukwaya <i>et al</i>. [27].

<p>Red labels represent <i>Ae</i>. <i>bromeliae</i> while blue labels are <i>Ae</i>. <i>lilii</i>. Sequences from Mukwaya <i>et al</i>. [<a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0004250#pntd.0004250.ref027" target="_blank">27</a>] (+) are annotated. Bootstrap support values above 55% are shown.</p