The project was carried out mainly at Chorkor, a suburb of Accra, from October, 2007 to July, 2008. The study area is located within the Dahomian ecological zone of West Africa and the vegetation is coastal savanna grassland. The climate is hot and humid and there is a bimodal rainfall pattern with a mean annual rainfall of about 1,300 mm. The mean daily temperature is 26 °C with a range of 18 °C–35 °C. The relative humidity can be as high as 97% in the mornings of wet seasons and as low as 20% in the afternoon of the dry seasons.

The study community, which is located at the outskirts of Accra, is densely populated, has a relatively high level of poverty, and is characterised by poor hygienic environments which could pose serious health risks to ready-to-eat or street food. The population of food vendors in the community is unknown, but sale of ready-to-eat food appears to be an important occupation, in addition to fishing, the main occupation.

The project involved two main phases. The first phase focused on data collection on the food handling practices of street food vendors. An attempt was made to determine the population of food vendors in the study community. This was done by collecting information from the Chief of the community and other community officials who interact with food vendors. The information collected showed that the population of food vendors in the community was about 250. Following this, a stratified method of sampling was used to statistically sample 100 food vendors of the various major food types sold, for interview using a structured questionnaire (with a Leikert scale). A total of 27 food vendors from other parts of Accra were also interviewed. The data collected focused primarily on: (i) food handling practices; (ii) environmental and personal hygiene; (iii) risk factors of oro-faecal transmission, and (iv) incidence of diarrhoea and its treatment. Additionally, data on other market factors not directly related to risk such as food types sold and market size of vendors were also collected. Personal hygiene of the vendors was assessed by their cleanliness of appearance and health, while environmental hygiene was assessed by cleanliness of the food environment, plates and other food equipment. Apart from personal and environmental hygiene, which involved data collection by observation, the other data collected were self reported by the vendors. Stool specimens were collected from all the vendors and screened for enteric pathogens of bacteria and parasites by standard microbiological methods [7–10]. For bacterial pathogens, specimens were cultured on MacConkey agar and Salmonella-Shigella agar, and the isolated organisms were identified by inoculation of various biochemical reagents. In the case of parasites, specimens were analysed microscopically.

The second phase of the project entailed a one-day risk communication workshop in which food vendors were invited to participate without incentive. At the workshop food vendors were trained in food handling using the WHO keys of safer food [6], and information synthesized from data collected in the first phase. In a highly simplified form, the vendors were also given lessons and training in various food safety related subjects, including food and personal hygiene, environment and food safety, transmission of food-borne infections, control of foodborne infections, and economic importance of food safety. The lessons presented at the workshop were developed and validated by the investigators of the study prior to the workshop. The language of communication used at the training workshop was a local dialect understood by the vendors. Following the training, data was collected from the vendors on their food handling practices after a period of six months, through a one time survey. The data was analysed and compared with data collected on food handling practices of the vendors prior to the training workshops, to help assess the impact of the training on food handling. The training impact was further evaluated by: (i) the extent to which the trained vendors shared knowledge from the workshop with others, and (ii), the assessment of the workshop by the food vendors.

The laboratory and interview data collected from the food vendors was entered in MS-EXCEL and MS-ACCESS and analysed using SPSS to help address the objectives of the study. The strategies taken to analyse the data collected in the study, involved descriptive statistics, including geometric means, frequencies, ranges and prevalence rates of the study variables. Significant differences, associations, and interrelationships of the variables were also assessed.

The protocol of the study was submitted to the Ethical Committee of The University of Ghana Medical School and consent was obtained from food vendors and the Local Authority before the interviews and training workshop.

The demographic characteristics of the food vendors sampled are reported as follows. Overall, the food vendors comprised 125 (98.4%) females and two (1.6%) males. The age range of the food vendors was 16–70 years with a mean age of 34 years (SD = 11.8). A total of 116 (91.3%) of the vendors were Christians, 9 (7.1%) were Moslems, while two (1.6%) did not have any religious affiliation. Overall, 33 (26%) of the food vendors did not have any form of education, 40 (22%) had Junior Secondary School Education, 28 (22%) had Primary School Education, 17 (13.4%) had Senior Secondary School Education, while nine (7.1%) had Middle School Leaving Certificate Education.

No intestinal bacterial pathogen was isolated from stool specimens of any of the food vendors screened. However, a parasite, namely Giardia lambia, was isolated at a prevalence rate of 1% (1/100). A proportion of 12% (16) of the food vendors experienced diarrhoea every month, 15% (19) experienced it at intervals of 3-months, 4.7% (6) experienced it at intervals of 6-months, 19.7% (25) experienced it yearly, while 45.7% (58) experienced it at intervals of more than one year. A proportion of 2.4% (3) of the vendors had no experience of diarrhoea.

Toilet attendance of the vendors and hand washing afterwards (prior to the training workshop) were as follows. In a day, during food sales, 69.3% (88) of the food vendors attended the toilet once for defaecation, 11% (14) attended the toilet twice, 1.6% (2) attended the toilet three times, while 18.1% (23) did not attend the toilet at all. After defaecation, 92.1% (117) mentioned that they always washed their hands, 3.1% (4) washed hands sometimes, while 4.7% (6) never washed hands at all. The food vendors had different modes of hand washing after defaecation, and the type of water used was portable water (pipe borne water) A total of 86.6% (110) food vendors washed their hands with water and soap, while 12.6% (16) washed hands with only water. A proportion of 71.2% (108) of the vendors discarded the water after washing, 18.2% (12) used the water for washing food equipments, while 10.6% (7) reused the water in subsequent hand washings. A high majority of 98.4% (125) of the food vendors had knowledge that some human pathogens could be transmitted by the oro-faecal route. Generally, there were no significant differences in the practices, attitudes and perceptions of the vendors based on their demographic characteristics at p < 0.05.

In the assessment of environmental hygiene of the vendors, 16.5% (21) was scored as poor, 47.2% (60) was fair, while 34.6% (44) was good. In terms of personal hygiene, 4.7% (6) of the vendors had poor hygiene, 57.5% (73) had hygiene rated as fair, while 36.2% (46) had good hygiene.

The food handling practices of the food vendors prior to the training workshop were as follows. Before food preparation, all the food handlers washed their hands; 57% of the vendors washed hands always, 12% washed most times, while 31% did not wash often. During food preparation, 2% of the vendors admitted not using clean surfaces, while 98% used clean surfaces to various extents as follows: 47% used clean surfaces always; 17% used them most times, while 34% did not use them often. The use of separate equipment for raw and cooked food or separating the two categories of food during storage was not practiced by 1% of the vendors. On the usage of equipment, 35% of the vendors always used separate sets of equipment for raw and cooked food, 21% used separate equipment most times, while 42% did not use them frequently. On the practice of storing raw and cooked food separately, 27% of the vendors always stored raw and cooked food separately, 23% stored them separately most times, while 49% did not do this often. Pipe borne water was the water source used by 99% of the vendors for cooking and food handling, while 1% of the vendors used well water. A proportion of 81.9% of the food vendors stored food overnight and sold to consumers, 55.9% used refrigeration facilities for storage, while 15.7% kept food uncovered. In a day, one food vendor sold food to an average of 117 people ranging from 1–500 people. A wide range of ready-to-eat food was sold by the vendors (Table 1). Generally, there were no significant differences in the food handling practices of vendors based on their demographic characteristics at p < 0.05.

Overall, a total of 100 food vendors (including the majority of those who took part in the pre-workshop survey) were trained in various aspects of food safety. There was also an interactive phase of the workshop, during which the food vendors asked pertinent questions related to food safety and suggested ways the safety of ready-to-eat food could be improved. This actually enriched the workshop, and made knowledge transfer to the vendors easier. Collecting and analysing stool specimens from the vendors before the training was useful because it helped to inform the vendors practically about oro-faecal transmission, and the possible role of food vendors in the transmission process. Table 2 shows the self-reported food handling practices of the vendors before and after the training workshop, as well as the overall impact of the training. Impact assessment of the training showed quite a favourable outcome: overall, 67.6% of the food vendors had acquired some knowledge and were putting it into practice; 27% had also acquired some knowledge but were not practicing it; while 5.4% indicated not acquiring any knowledge.

A proportion of 42% of the food vendors indicated that they had shared the knowledge they acquired from the training workshop with other people. Assessment based on specific indicators related to the WHO food safety keys showed the following: the rate of washing hands always before and during food preparation improved from 57% to 100%. Separation of raw and cooked food always during storage and using separate sets of equipment for them was practiced by 33.3% of the vendors after the workshop. However, before the workshop, 13.4% of the vendors used separate equipment for the two types of food while 91.3% separated the two types of food during storage. Keeping food at safe temperature was assessed only after the workshop, and showed that 27% of the vendors always kept food in the refrigerator if stored overnight, while 59.5% always reheated cooked food before selling.