ABSTRACT

Corresponding Author:
Dr. Kirti Malpekar,
404, Audumber So.,
3rd Akkalkot Lane,
Khadilkar RD,
Girgaon, Mumbai-400004.
E-mail: kirtimalpekar@yahoo.com

ABSTRACT

Food borne diseases are a global public health burden. Food handlers play a major role in the transmission of foodborne diseases. This study was aimed at investigating the presence of intestinal parasites, S. typhi carrier rate and associated risk factors among food handlers in a metropolitan city.

MATERIALS AND METHODS

A cross-sectional survey was conducted among 200 food handlers working in different food service establishments. A pre-tested structured questionnaire was used to collect data on age, sex, years of service, previous deworming, status of typhoid immunization and hand washing practices. Stool samples were processed for intestinal parasites and S. typhi, as per the standard laboratory methods.

RESULTS

In the present study, majority of the food handlers were males 185/200 (92.5%), 90/200 (45%) were aged between 30-50 years, and 72/200 (36%) had less than one year experience. Intestinal parasites were detected in 31/200 (15.5%) and S. typhi in 2 (1%). Of the 31 parasites, 11 (35.5%) were seen by direct saline technique and additional 20 (64.5%) by formol-ether concentration technique. The parasites found in descending order of frequency among the food handlers were: fertilized eggs of Ascaris lumbricoides 8.5% (17/200), cyst of Giardia (3.5%), cyst of Entamoeba histolytica 2% (4/200), eggs of Taenia spp. 1% (2/200) and eggs of Trichuris trichiura 0.5% (1/200). The association of years of work experience was inversely proportional to parasitic infection and directly proportional to history of previous deworming, both of which were statistically significant.

CONCLUSION

Inexperience and lack of awareness about hygiene in food handlers play a major role in the transmission of food-borne infections. Training on food safety and periodic focused medical check-up can help to control the spread of infection in the community. Laboratory investigation should include formol ether concentration technique to enhance diagnosis.

KEYWORDS

Intestinal Parasites, Food Handlers, Risk Factors.

INTRODUCTION

The term “food handler” means “person who in the course of the normal routine work come into contact with uncovered food not intended for personal use.”^[1] Food handlers play a major role in the transmission of food-borne diseases, which are a major public health problem across the globe. This is particularly true in developing countries due to lack of optimal food handling practices and environmental sanitation. The World Health Organization (WHO) estimated that in developed countries up to 30% of the population suffer from food-borne diseases each year, whereas in developing countries up to 2 million deaths are estimated per year.^[2]Large cities which attract hordes of tourists witness proliferation of eateries ranging from expensive restaurants

Studies showing almost similar rate of intestinal parasite infection rate among food handlers compared to present study (15.5%) were V. Mohan et al^[22] 2001 (14%) (Amritsar), Al-Lahham AB et al^[23] 1990 (18%) (Irbid, Jordan) and Salem et al^[24] 1998 (13.5%) (Jeddah, Saudi Arabia). Studies showing lower prevalence of intestinal parasite infection in food handlers than our study; (15.5%) were Khurana et al^[25] 2008, (1.3-7%) North India, Saeed and Hamid et al^[26] 2010 (6.9%) Omduram, Sudan, Gunduz et al^[27] 2008 (8.8%), Manisha, Turkey. Previous study from Mumbai (2010) (Prateek et al)^[3] revealed overall parasitic infection rate 26.3%. Reduction of parasite infection among food handlers in our study may be due to improvement of personal hygiene and periodic check-up of food handlers and increase knowledge about hygiene. According to our knowledge, most of the studies from across the world showed higher intestinal parasite infection rate in food handlers compared to Mumbai (15.5%). High prevalence of intestinal parasite is largely due to poor personal hygiene, lack of environmental sanitation and ignorance of health promotion practices.

In present study, distribution of parasites found in descending order of frequency were fertilized eggs of Ascaris lumbricoides 8.5% (17/200), cyst of Giardia (3.5%), cyst of Entamoeba histolytica 2% (4/200), eggs of Taenia spp. 1% (2/200) and eggs of Trichuris trichiura 0.5% (1/200). There was no evidence of Trematodes, Hookworm and Strongyloides.

Studies showing higher number of Ascaris lumbricoides infection among food handlers compared to our study are V. Mohan et al^[22] 2001, Amritsar (28.6%) Bayeh Abera et al⁸ 2010, Bahir Dar Town, North West Ethiopia (11.7%) Gashaw Andargie et al^[9] 2008, Gondar Town, North West Ethiopia (18.11%). Studies showing lower number of Ascaris lumbricoides among food handlers compared to our study are Prateek et al^[3] 2010, Mumbai (5.1%) Anant et al^[4] 2011, Solapur (6.5%), Al-Lahham AB et al^[23] 1990, Jordan (4.9%) Ayeh et al^[21] 2009, Accra Ghana (5%), S. Haj Baswaid et al^[28] 2008, Yemen (1.7%) and Majed H. Wakid et al^[13] 2009, Makkha (0.8%).

In our study, Salmonella typhi was isolated in 1% (2/200) of food handlers; there was no Shigella infection. The two food handlers infected with Salmonella typhi were most likely asymptomatic carriers, as they did not reveal overt clinical manifestation. Studies showing higher carrier rate of Salmonella infection among food handlers compared to our study were - Khurana et al 2008.^[25] North India (1.3%), Al-Lahham AB et al^[23] 1990 Jordan (6%), Feglo PK et al^[29] 2004 Ghana (2.3%), Lanata CF et al^[30] (5%), Senthilkumar et al^[31] 2005 Namakkal District, Tamilnadu (17.14%). Studies showing no Salmonella carrier compared to our study were Gashaw et al^[9] 2008 Gondar Town, North West Ethiopia; Malhotra et al2006 North India.^[7]; Simsek Z et al 2010 Sanliurfa.^[19] Studies showing almost similar carrier rate of Salmonella compared to our study (1%) were Bayeh et al^[8] 2010 Bahir Dar Town, North West Ethiopia (1.85) Mulat Dagnew et al^[32] 2013, Gondar University, North West Ethiopia (1.3%), Misganaw et al^[33] 2013, Southern Ethiopia (0.93%) Gashaw et al^[9] 2008 Gondar Town, North West Ethiopia and Lanata CF et al had reported zero percent Shigella infection.^[30] among food handlers which was similar to our study. Studies done elsewhere showed prevalence of Salmonellosis among food handlers ranges from 0.032-11% [Murakami et al^[34] 2007, Abera et al⁸ 2010, Saeed and Hamid.^[26] 2010, Vaeteewootacharn et al 2008.^[35]

In our study parasites were detected in 11/200 (5.5%) by both direct mount and formol ether concentration technique and 31/200 (15.5%) parasites were detected by formol ether concentration technique. Therefore, we can see that additional 20/200 (10%) food handlers were detected only by formol ether concentration technique, i.e. they were missed by direct examination. If we take formol ether concentration technique as gold standard of parasite infection diagnosis in stool, sensitivity of direct mount is 35.48% and specificity is 100%. A study from Khartoum, Sudan in 2009 by M.A. Babiker et al has reported that direct mount and formol ether concentration method had detected parasites in 18.6% and 29.4% food handlers respectively.^[10] Here additional 10.8% food handlers were detected by formol ether concentration method only, which is similar to our study (10%). However sensitivity of direct mount compared to formol ether concentration was higher (63.26%) than our study (35.48%). Our study shows that although direct fecal smear is simpler to perform, formol ether concentration technique is far more accurate in providing correct laboratory diagnosis. This requires additional laboratory requirements, such as additional reagents necessitating additional time and effort. These additional requirements will certainly affect the cost of diagnosis by at least 5 times, but individuals or food establishments may be willing to pay the additional cost of more accurate diagnosis. (Esparar et al 2004, Manila).^[20]

The association between intestinal parasite infection and years of experience was statistically significant (p value 0.003; Pearson chi square test). Those, who were more experienced (>3 yrs.) were less infected by parasites. The association between years of experience and previous deworming was also statistically significant (p value <0.0001); years of experience being directly proportional to positive deworming history. It indicates that previous deworming and awareness, which comes with increased years of work experience may be the cause of low parasite infection rate.

In our study, 20/200 (10%) food handlers had received typhoid vaccine. One study by Maizun et al, 2002 in                 Malaysia.^[36] has reported higher i.e. 59.6% typhoid immunisation rate among food handlers, while Prateek et al^[3] 2011 from Mumbai has reported lower i.e. 5.1% typhoid immunisation rate.

Although, no statistically significant association had been found in present study between hand washing (after touching body parts or any dirty material) and parasite infection rate, those who practiced hand washing were less infected (13.8%) than those who did not (30%). This indicates that poor hygiene practice was associated with high rate of intestinal parasitic infection. An Iranian study.^[37] showed that reduced hand washing with soap prior to eating after using the toilet or in both situations and contact with soil significantly increased the risk of infection (p=0.0004, 0.01, 0.0001), which was also noted by workers in Solapur.^[4] and Mecca, Saudi Arabia.^[38] Improper hand washing before handling food is one obvious route for dissemination of infections. Parasite eggs in the soil can be transmitted to vegetables, then on to hands and hence directly into the mouth.^[39]

The limitation of our study was the small sample size, due to limited resources and manpower. The educational status and living conditions of food-handlers, which influences personal hygiene was not assessed. Considering the large size of the food sector, more studies need to be performed on a large scale with increased sample size, covering a wide range of food establishments across the city.

CONCLUSION

Intestinal parasitic infection among food handlers poses a significant health hazard. Good hygiene and safe food-handling should be exercised by food handlers. Strict implementation of periodic medical check-up in addition to proper health education will help to reduce the infection and thereby its spread in the community. To enhance diagnosis, the screening of food handlers should include formol ether concentration technique for stool examination, as it imparts higher yield of parasites compared to direct wet mount. Preventive measures such as typhoid immunisation and regular deworming with appropriate anthelmintics are recommended.

ACKNOWLEDGEMENT

The authors thank the Public Health Department of MCGM, Ward Officer and Sanitary Inspector for their cooperation and support. We acknowledge all the food handlers for their participation and the Department Technical Staff for assistance.