Food handlers : an important reservoir of protozoans and helminth parasites of public health importance

This is an Open Access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Abstract Food handlers plays a primary role in the transmission of pathogenically important protozoans and helminth parasites. This study was aimed to evaluate the prevalence of intestinal pathogenic protozoans and helminth parasites among food handlers in and around University of Malakand, Lower Dir, Pakistan. Stool samples were collected from 642 food handlers (all of male) in a cross-sectional study from January to November, 2017. Wet Mount Techniques and concentration methods by using salt and formol–ether solutions. Three hundred and eighty four cases (59.8%) were found infected with one more parasites. Most of the individuals were found infected with helminth (47.6%) as compared to intestinal protozoans (0.93%). Seventy two cases (11.2%) of the cases presented mixed infection with both intestinal protozoan and helminth parasites. The order of prevalence for intestinal helminth was Ancylostoma duodenale (n = 258, 40.1%), followed by Taeniasa ginata (n=96, 14.9%) Ascaris lumbricoides (n = 54, 8.40%) and Trichuris trichura (n=30, 4.60%). For intestinal protozoa, Entamoeba histolytica/dispar (n = 36, 5.64%) was the only protozoan detected. Mono-parasitism was higher than poly-parasitism. Family size income and education level were the factors significantly (P<0.05) associated in the parasites prevalence. Current research showed that IPIs are primarily the foodborne pathogens still an important public health problem in Pakistan. Effective control programs on parasitic diseases transfer and their associated factors are recommended.


Introduction
Food protection is a global concern and a substantial number of food borne illnesses is due to unsafe foodhandling practices. These diseases were originated to affect more than 30% of the people in industrialized nations. The problem is estimated to be even more complicated in unindustrialized countries. Thus, improving the consumer understanding of safety rules would reduce pathogenic microorganisms in food. Most of the academic awareness has been given to consider the knowledge on practices of food safety throughout world (Ahmed et al., 2017). Information about food handlers is a required factor in controlling the food borne diseases. Government of Pakistan has issued 22070 certificates to international and 8857 to local food handlers (Ahmed et al., 2017).
The infection caused by intestinal parasites is an important health issue in unindustrialized countries, ranges from 30 to 60% as compared to 2% in the developed nations of the world (Shahnazi et al., 2009). Intestinal parasite prevalence is mainly depend on nutrition, culture, socio environmental factors and hand washing. Intestinal parasitic infection is common disease worldwide. According to WHO two billion people are affected by helminth parasites in the world and closely two third is infected with one species of intestinal parasites (Tulu et al., 2016).
The infection caused by protozoan parasite, the Giardia spp., and nematode worms such Ascaris lumbricoides and Trichuris trichiura, infect one fourth of the population in the globe (Harhay et al., 2010) as the most comman intestinal parasites in the world. The infection cause by A. lumbricoides in some parts of Pakistan has reached to 55.8 percent (Khan et al., 2017a).
Several studies conducted previously in Pakistan were focused on particular areas and targeted populations, however information on prevalence of intestinal protozoan and helminths in food handlers in the study area is lacking. Current study was therefore designed to determine the prevalence of intestinal parasite in food handlers in and around the University of Malakand, Lower Dir, Khyber Pakhtunkhwa, Pakistan.

Study area and participants studied
Current research was conducted around the University of Malakand, Pakistan between January to November 2017. Dir Lower is located 263km in northwest of Islamabad (capital of Pakistan). It has a Lat= 35º 11'51.57" North and Long=71º52'29.72 East, characterized by raining in summer than in winters. The average temperature in Dir is 22.8 °C. Lower Dir lies at 8500ft above sea level and shows 1588mm annual precipitation rate. The food handlers participated in current research were showing the symptoms related to intestinal parasitic infections however some of them were asymptomatic. These participants had belong to different sites and location of the region serving in these food stations.

Ethical approval and inform consent
The study was approved by the ethical review board, University of Malakand. A written consent was obtained from all the participants on the purpose and importance of the study. Each of the participants was interviewed on their life style i.e family size, number of individuals living in each family, income per month and education status of the parent's parents/guardians. The interview was conducted in local language (Pashto) and then translated into the English.

Stool sample collection
The consented food handlers were provided with a clean plastic bottle containing 10% preservatives (Formaldehyde and Merthiolate iodine) a wooden spatula, with an identification number. During collection of stool sample a questionnaire for each food handler was also filled. The collected faecal specimens were brought to the laboratory of Parasitology, Department of Zoology, University of Malakand and processed as below:

Physical examination
Each of the faecal samples collected were observed through naked eyes or by using the hand lens for the presence of proglottids of the tapeworm or any adult parasitic worm.

Microscopic examination
Using normal saline and iodine preparation the sample was examined under microscope. The slide was studied for at least 10 minutes. Initially under low power lenses then under high power bright field. The procedure of Formalin Ethyl Acetate is used (Mali et al., 2008).

Direct smear method
One up to two grams of feces was mixed in one to three drops of normal saline or Lugol's iodine solution. A cover-slip was placed on the slide and examined under 10X and 40Xpower objective lenses of a microscope. Saline direct smear method is found useful for the detection of movement of trophozoites stages and helminths ova. Iodine direct smear method was useful for the identification of the typical features of protozoa cyst (E. histolytic/dispar: the intestinal pathogenic protozoan). Parasitological assessment was performed by the first author of this manuscript.

Formol-ether concentration
In formol-ether concentration method, about one gram of feces was mixed in 10% formalin solution and formolether concentration technique was applied (Williams, 1992).

Discussion
Food safety can prevent food from contacting food borne pathogens during preparation and storage of food in different ways. Food handlers links the food from industry to the market and then to consumer. In this way food can transmit food borne pathogens. All the food handlers should be referred to a healthy centre (Medical Diagnostic Laboratory) to diagnose for intestinal parasitic infection prior to receive health certificate.
Infection caused by intestinal parasites is endemic in the world and have designated as one of the main sources of disease and illness (Keiser and Utzinger, 2010). Intestinal parasitic infections are usually found in the people of poor population, in the people of lacking access to safe water supply and lacking of hygiene. All these factors are variably associated in the distribution of intestinal

Statistical analysis
Collected data was analysed using the Graph Pad version 5. The P value less than 0.05 at 95% CI was considered significant (P <0.05).
The highest 83.1% rate of prevalence was observed in present study (Khan et al., 2017a) and lowest in general survey 30.4% (Bilqees et al., 1982). Nevertheless, by comparing the findings of the current research to the studies conducted previously, we noticed that our finding is somewhat higher as compared to other studies conducted in Pakistan.
The highest prevalence of intestinal parasitic infection was reported in India 97.4% (Kang et al., 1998), Ecuadoria 90% (Sackey et al., 2003) and Swat district, Pakistan 83.1% (Khan et al., 2017a). The higher rates of prevalence in these parts of the world may be due to inadequate hygiene and rural backgrounds.
Comparatively high prevalence of helminth parasites was seen in the present study findings. This variation may likely be explained by the climate of the study area which is known to be moist in the entire year. This condition might be suitable for development of infective stages of helminth eggs that become infective if ingested. A. duodenale was the most prevalent helminth in present study. Safe water supply provision, latrines development, hygiene improvement and awareness about transmission of parasitic infection should be ensured to minimise these infections.