Table 2.

Experimental design and locations of reviewed studies that reported the prevalence of Listeria spp. and L. monocytogenes in Ethiopian dairy products.^a

Reference	Region	Town	Dates	Place of sampling	Study design	Sample size calculation	Detection method	Confirmation method
Molla et al. (2004)	Addis Ababa	Addis Ababa	Sep 2003 to Apr 2004	Purchased from retail supermarkets and other stores	Cross-sectional	Not stated	Primary enrichment in half Fraser broth, secondary enrichment in Fraser broth, isolation on PALCAM	Gram staining, motility, haemolysis, catalase, CAMP tests, rhamnose, xylose and mannitol fermentation
Mengesha et al. (2009)	Addis Ababa	Addis Ababa	Sep 2004 to Mar 2005	Purchased from 37 supermarkets and pastry stores	Not stated	Not stated	Primary enrichment in half Fraser broth, secondary enrichment in Fraser broth, isolation on PALCAM and Oxford	Haemolysis, CAMP test, rhamnose, xylose and mannitol fermentation, serotyping
Gebretsadik et al. (2011)	Addis Ababa	Addis Ababa	Nov 2008 to Mar 2009	Purchased form retail shops, cafeterias and markets	Cross-sectional	Random sampling; no sample size calculation reported	Pre-enrichment in BLEB, primary enrichment in UVM I and secondary enrichment in UVM II broth, isolation on PALCAM	Gram staining, motility, haemolysis, catalase, CAMP tests, rhamnose, xylose and mannitol fermentation
Derra et al. (2013)	Addis Ababa	Addis Ababa	Jul to Dec 2006	Purchased at retail markets, shops, supermarkets and food vendors	Cross-sectional	Not stated	IDF, 1990	PCR and PFGE
Muhammed et al. (2013)	Oromia	Jimma	Oct 2010 to Mar 2011	Purchased at cafes, milk open markets and pastries.	Cross-sectional	Random sampling. Sample size determined based on P = 13%, d = 5% and confidence = 95%	Sample dilution 1:10 in buffered peptone water. Enrichment in Listeria enrichment broth, isolation on Oxford	Gram staining, motility, haemolysis, catalase, CAMP tests, rhamnose, xylose and mannitol fermentation
Garedew et al. (2015)	Amhara	Gondar	Nov 2012 to Jun 2013	Purchased from randomly selected dinning houses (cafeterias, hotels, restaurants and retail shops)	Cross-sectional	For all products combined. Sample size determined based on P = 50%, d = 5%, confidence = 95%.	Primary enrichment in half Fraser broth, secondary enrichment in Fraser broth, isolation on PALCAM	Gram staining, motility, haemolysis, catalase, CAMP tests, rhamnose, xylose and mannitol fermentation
Seyoum et al. (2015)	Addis Ababa	Addis Ababa	Nov 2011 to Jul 2012	Purchased from supermarkets	Not stated	Not stated	Enrichment in LEB broth, isolation on Oxford agar	Catalase, xylose, mannitol and rhamnose fermentation, CAMP test
Fisseha (2017)	Oromia	Bishoftu and Dukem	Nov 2016 to Apr 2017	Restaurants, milk collection centres, supermarkets, cafeterias and small ice cream shops	Cross-sectional	Sample size determined based on P = 32.6%, d = 5%, confidence = 95%.	Enrichment in LEB broth, isolation on PALCAM and OXA agar	Gram staining, motility, haemolysis, catalase, CAMP tests, rhamnose, xylose and mannitol fermentation
Girma and Abebe (2018)	Amhara	Debre-birhan	Not mentioned	Dairy producers that deliver their milk to collection centres	Cross-sectional	Sample size determined based on P = 50%, d = 5%, confidence = 95%	Primary enrichment in half Fraser broth, secondary enrichment in Fraser broth, isolation on Oxford	Gram staining, motility, haemolysis, catalase, CAMP tests, rhamnose, xylose and mannitol fermentation

^aAbbreviations: d, precision; P, prevalence; CAMP test, Christie-Atkins-Munch-Peterson test; LEB, listeria enrichment broth; OXA, Oxford agar; PALCAM, polymyxin acriflavine lithium chloride ceftazidime aesculin mannitol agar; PCR, polymerase chain reaction; PFGE, pulsed-field gel electrophoresis; UVM, University of Vermont broth.