|Year : 2015 | Volume
| Issue : 2 | Page : 123-126
Soil contamination with Cryptosporidium spp. in the west of Iran
Mohsen Ghomashlooyan1, Mohammad R Vafaei1, Hamed Kalani1, Farzaneh Mirzaei1, Mehdi Azami2, Rasool Jafari1, Mohammad Falahati1, Ahmad Hosseini Safa3, Mohammad A Mohaghegh1
1 Department of Parasitology and Mycology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
2 Skin Diseases and Leishmaniasis Research Center, Isfahan University of Medical Sciences, Isfahan, Iran
3 Department of Medical Parasitology and Mycology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
|Date of Submission||20-Sep-2015|
|Date of Acceptance||24-Nov-2015|
|Date of Web Publication||27-Jan-2016|
Mohammad A Mohaghegh
PhD., Department of Parasitology and Mycology, Faculty of Medicine, Isfahan University of Medical Sciences, Isfahan
Source of Support: None, Conflict of Interest: None
Cryptosporidium spp. is a coccidian protozoan parasite that causes gastrointestinal disorders in human and animals. Several studies have demonstrated that the soil of public parks and schools presents an important source of infection which has a significant impact on public health. Children are the main group affected by accidentally ingesting contaminated soil.
Aim of the work
The aim of this study was to detect the presence of Cryptosporidium spp. oocysts in soil collected from primary schools and parks in Kermanshah city, west of Iran.
Materials and methods
The survey was conducted from August to December 2014 in Kermanshah city. Altogether 192 randomly selected soil samples were collected from 24 parks and 24 primary schools in six regions. The samples were screened for Cryptosporidium spp. oocysts using Sheather's flotation method and modified Ziehl-Neelsen staining.
Out of 192 samples, 49 (25.5%) were found to contain Cryptosporidium spp. oocysts. Data analysis using χ2 -test revealed that there was no significance among parks and primary schools in terms of the contamination rate (P = 0.24). Furthermore, there was no significant difference between the contamination rate and different regions of Kermanshah (P = 0.36). Regions 3 and 4 had the highest contamination rate (34.4%) and the lowest was for region 6 (15.6%).
Considering human infection with different Cryptosporidium spp. and the increase in numbers of immunocompromised patients, high contamination of soil with this parasite in Kermanshah stands as a serious problem. Consequently, health promotions, public education, improving sanitation conditions, especially for the underprivileged, are the keys to success in preventing the spread of Cryptosporidium spp. infection. In this regard, findings of this study can be used as a basis for preventive programs and development strategies targeting groups for the prevention of greater risk of cryptosporidiosis.
Keywords: contamination, Cryptosporidium spp., Iran, parks, primary schools
|How to cite this article:|
Ghomashlooyan M, Vafaei MR, Kalani H, Mirzaei F, Azami M, Jafari R, Falahati M, Safa AH, Mohaghegh MA. Soil contamination with Cryptosporidium spp. in the west of Iran. Parasitol United J 2015;8:123-6
|How to cite this URL:|
Ghomashlooyan M, Vafaei MR, Kalani H, Mirzaei F, Azami M, Jafari R, Falahati M, Safa AH, Mohaghegh MA. Soil contamination with Cryptosporidium spp. in the west of Iran. Parasitol United J [serial online] 2015 [cited 2021 May 12];8:123-6. Available from: http://www.new.puj.eg.net/text.asp?2015/8/2/123/175010
| Introduction|| |
Cryptosporidium spp. is a coccidian protozoan parasite that causes gastrointestinal disorders in human and animals. The infection is more common in children as a self-limiting disorder, but in immunocompromised patients, it can be considered as a serious health risk , . This parasite is considered as one of the main factors in the outbreak of diarrhea and vomiting in developing countries  . Cryptosporidiosis is one of the most important water-borne diseases, and one of its clinical manifestations is self-limiting watery diarrhea that persists from a few days to a lot longer  . There are several species that are morphologically indistinguishable from each other  . Cryptosporidiosis is very common among mammals, some of which are closely related to humans. Cryptosporidium hominis, Cryptosporidium parvum, Cryptosporidium canis, Cryptosporidium meleagridis, Cryptosporidium wrairi, Cryptosporidium felis, Cryptosporidium suis, Cryptosporidium andersoni, and Cryptosporidium muris are species capable of infecting humans ,,,, , and the first two species are commonly reported to infect humans  . Several studies showed that there is an indirect relationship between the duration of cryptosporidiosis and CD4 + cell count. Furthermore, ectopic forms of this disease have been reported in HIV/AIDS , and non-AIDS immunocompromised patients, including hemodialysis, diabetic, organ transplant, and cancer patients ,, .
Soil is an important source for diseases transmission, identified as soil-transmitted diseases. A large number of pathogens are able to bind to soil particles and spread in the environment  . Therefore, soil contamination with pathogens in an area is of public health importance. Accordingly, in recent years many studies have been conducted to determine the prevalence of some parasitic agents in the soil, especially in areas where people live ,, . Epidemiological studies in Korea  , Mexico  , Spain  , and Brazil  showed that the prevalence of Cryptosporidium spp. oocysts in the soil was 32.4,% 52%, 9%, and 7.4%, respectively. In a recent study done in Isfahan, Iran, oocysts were observed in 31 out of 140 soil samples (22.14%)  . One of the major reasons for the spread of soil-transmitted parasitic diseases is the use of manure on farmlands, parks and green space. Consequently, these areas can act as an important source of Cryptosporidium spp. oocysts infection of people. Therefore, the aim of this study was to determine the occurrence of Cryptosporidium spp. oocysts in the soil collected from primary schools and parks in Kermanshah city, west of Iran.
| Materials and methods|| |
Type of study:
This study was designed as a cross-sectional study.
Kermanshah city is located in the center of Kermanshah province, west of Iran. According to the 2011 census, its population is 851,405. The city has a mountainous climate and is surrounded by the Zagros Mountains, being cold and snowy in winter and rainy in spring and autumn. This city is a major center for agriculture in the west of Iran, producing grain, rice, vegetables, fruits, and oilseeds. Kermanshah is divided into six regions, including center (regions 1, 2), east (region 3), south (region 4), north (region 5) and west (region 6).
This survey was conducted from August to December 2014. A total of 192 soil samples were collected from 24 public parks and 24 primary schools, four samples from each region of Kermanshah city. The samples were collected from four parks and four primary schools. Accordingly, about 200 g of soil was gathered from an approximate depth of 2-5 cm. The samples were placed in plastic containers, labeled with a number and dried in air.
Flotation technique was used for Cryptosporidium spp. oocyst isolation. The dried soils were passed through a sieve and then 2 g of each soil sample was poured into a centrifuge tube. Afterwards, 10 ml Tween 80 solution with a concentration of 0.05% was added to each tube and mixed well with the soil. The mixture was centrifuged at 1500 rpm for 5 min. The supernatant was discarded and then the sucrose solution (1.2 g/ml) was added to 1 cm from the top of the tubes. The tubes were centrifuged again and then gently filled to the top with sucrose solution. Finally, a separate glass slide was placed on the tubes for 30 min  .
Cold modified Ziehl-Neelsen staining method
A separate smear was prepared from each sample and allowed to air dry. The smears were fixed by absolute methanol and then stained using cold modified Ziehl-Neelsen staining method. Initially, the smears were stained in carbol Fuchsin solution for 15 min, rinsed, and then decolorized with hydrochloric acid (1%) for 30 s. The smears were rinsed in tap water again and restained with 0.25% methylene blue for 30 s as a background color and then rinsed. Finally the air dried slides were examined for the presence of Cryptosporidium spp. oocysts using ×1000 of magnification  .
| Results|| |
Out of 192 soil samples, 49 (25.5%) were found to contain Cryptosporidium spp. oocysts ([Table 1]). The contamination rate in public parks and primary schools was 21.9 and 29.2%, respectively. Data analysis using χ2 -test revealed that there was no significant occurrence of oocysts contamination between parks and primary schools (χ2 = 1.34, P = 0.24). Furthermore, there was no significant difference between the contamination rate and different regions of Kermanshah (χ2 = 5.39, P = 0.36). Regions 3 and 4 were found to be highly contaminated (34.4%) compared with the other examined sites and the lowest rate of contamination (15.6%) was observed in region 6.
|Table 1 Frequency of the soil samples according to regions and number of positive samples in parks and primary schools|
Click here to view
| Discussion|| |
Cryptosporidiosis in developing countries is a major cause of acute and persistent diarrhea, especially in immunocompromised individuals such as HIV/AIDS patients, malnourished children and elderly people  . It deserves mentioning that geophagia may occur in malnourished children, increasing the risk of acquiring the infection from soil. Many studies have also shown an association between socioeconomic status and prevalence of parasitic infections as an important factor in Iran ,,, . Oocysts of Cryptosporidium spp. are resistant to environmental conditions, and can even survive at −10°C  . This situation brings about an ideal condition for the transmission of this parasite. Therefore, the above-mentioned disorders may increase the chance of infection with Cryptosporidium spp. that may occur in pregnant women as well  .
In this study, we used the flotation procedure for isolation of Cryptosporidium spp. oocysts from soil. This method does not require sophisticated equipment and is easy to perform and also can be utilized in each laboratory. In addition, with this method, only infective oocysts are able to float above sucrose solution  . Accordingly, it is a useful method for estimating the abundance of active oocysts, infective to humans.
The results of the present study showed that the soils obtained from Kermanshah parks and primary schools could be a potential source for cryptosporidiosis for residents in this area. Because the ingestion of 30 Cryptosporidium spp. oocysts can cause clinical disease  , so it can be hypothesized that the possibility of infection in Kermanshah could be high. The prevalence of Cryptosporidium spp. infection in patients with AIDS has been reported as 26.7% in Kermanshah  , but the source of infection was not known and soil transmission is possible.
In the present study, high contamination of soil (29.2%) was observed in primary schools. In a previous study Cryptosporidium spp. were detected in the feces of 21.4% of children younger than 15 years of age with diarrhea in Iran  . The findings of the mentioned study show that the infection is highly prevalent in Iran. Also our results show a high contamination of soil with the parasite that may present a source of some proportion for infections in Iran. Researches for the prevalence of Cryptosporidium spp. oocysts in soil have rarely been performed and there were only two reports of soil contamination rate from Tehran (10%) and Isfahan (22.1%) , .
In another study on soil in southeast of New York state, where cattle are the main agents of soil contamination, oocysts of Cryptosporidium spp. were detected in 17% of samples  . Runoffs from contaminated soil and sewages are of the most important sources responsible for water contamination  . Mac Kenzie et al.  reported the massive outbreak of cryptosporidiosis in Milwaukee, Wisconsin, USA. The examination of contamination of rivers in Paris and its surrounding area showed 45.7% pollution with Cryptosporidium spp. oocysts. For this reason the role of soil in this contamination cannot be ignored  .
In conclusion results of this study suggested that the prevalence of Cryptosporidium spp. parasite in the soil has implications for the spread of human disease in these areas. As Cryptosporidium spp. infection can be mediated through soil, it is necessary to reduce contamination of this organism in view of public health. This study can be used as a basis for preventive programs, especially for at risk groups.
We would like to thank all the people who cooperated in this study.
Author contribution: Concept and design of study: MA Mohaghegh, M Azami and H Kalani; acquisition of data: MR Vafaei, AH Safa and M Falahati; analysis and interpretation of data: M Ghomashlooyan, F Mirzaei and R Jafari; drafting the article: MA Mohaghegh, M Ghomashlooyan and MR Vafaei; revising the first draft of the paper: M Azami, H Kalani, AH Safa, M Falahati, F Mirzaei and R Jafari; final approval of the version to be published: all authors.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
| References|| |
Shirley DAT, Moonah SN, Kotloff KL. Burden of disease from cryptosporidiosis. Curr Opin Infect Dis 2012; 25:555-563.
Azami M, Moghaddam DD, Salehi R, Salehi M. The identification of Cryptosporidium
species in Isfahan, Iran by PCR-RFLP analysis of the 18S rRNA gene. Mol Biol 2007; 41:851-856.
Abubakar I, Aliyu S, Arumugam C, Usman N, Hunter P. Treatment of cryptosporidiosis in immunocompromised individuals: systematic review and meta-analysis. Br J Clin Pharmacol 2007; 63:387-393.
Hunter PR, Nichols G. Epidemiology and clinical features of Cryptosporidium
infection in immunocompromised patients. Clin Microbiol Rev 2002; 15:145-154.
Xiao L, Sulaiman IM, Ryan UM, Zhou L, Atwill ER, Tischler ML, et al.
Host adaptation and host-parasite co-evolution in Cryptosporidium
: implications for taxonomy and public health. Int J Parasitol 2002; 32:1773-1785.
Fayer R, Santin M, Dargatz D. Species of Cryptosporidium
detected in weaned cattle on cow-calf operations in the United States. Vet Parasitol 2010; 170:187-192.
Chappell CL, Okhuysen PC, Langer-Curry RC, Akiyoshi DE, Widmer G, Tzipori S. Cryptosporidium
meleagridis: infectivity in healthy adult volunteers. Am J Trop Med Hyg 2011; 85:238-242.
Meamar AR, Guyot K, Certad G, Dei-Cas E, Mohraz M, Mohebali M, et al.
Molecular characterization of Cryptosporidium
isolates from humans and animals in Iran. Appl Environ Microbiol 2007; 73:1033-1035.
Cama VA, Bern C, Roberts J, Cabrera L, Sterling CR, Ortega Y, et al. Cryptosporidium
species and subtypes and clinical manifestations in children, Peru. Emerg Infect Dis 2008; 14:1567-1574.
Nazemalhosseini-Mojarad E, Haghighi A, Taghipour N, Keshavarz A, Mohebi SR, Zali MR, et al.
Subtype analysis of Cryptosporidium parvum
and Cryptosporidium hominis
isolates from humans and cattle in Iran. Vet Parasitol 2011; 179:250-252.
Wumba R, Longo-Mbenza B, Menotti J, Mandina M, Kintoki F, Situakibanza NH, et al
. Epidemiology, clinical, immune, and molecular profiles of microsporidiosis and cryptosporidiosis among HIV/AIDS patients. Int J Gen Med 2012; 5:603-611.
Feasey N, Healey P, Gordon M. Review article: the aetiology, investigation and management of diarrhoea in the HIV-positive patient. Aliment Pharmacol Ther 2011; 34:587-603.
Manesh RM, Safa AH, Sharafi SM, Jafari R, Bahadoran M, Yousefi M, et al.
Parasites and chronic renal failure. J Renal Inj Prev 2014; 3:87-90.
Baqai R, Anwar S, Kazmi S. Detection of Cryptosporidium
in immunosuppressed patients. J Ayub Med Coll Abbottabad 2005; 17: 38-40.
Jafari R, Gharibi Z, Fallah M. The prevalence of Cryptosporidium
infection among renal transplanted patients in Hamadan city, West of Iran. Avicenna J Clin Microb Infec 2014; 1:e19570.
McGechan M, Lewis D. SW-Soil and water: transport of particulate and colloid-sorbed contaminants through soil, part 1: general principles. Biosyst Eng 2002; 83:255-273.
Akao N, Ohta N. Toxocariasis in Japan. Parasitol Int 2007; 56:87-93.
Avcioglu H, Balkaya I. The relationship of public park accessibility to dogs to the presence of Toxocara species
ova in the soil. Vector-Borne Zoonot Dis 2011; 11:177-180.
Hong S, Kim K, Yoon S, Park WY, Sim S, Yu JR. Detection of Cryptosporidium parvum
in environmental soil and vegetables. J Korean Med Sci 2014; 29:1367-1371.
Balderrama-Carmona AP, Gortáres-Moroyoqui P, Álvarez-Valencia LH, Castro-Espinoza L, Mondaca-Fernández I, Balderas-Cortés Jde J, et al.
Occurrence and quantitative microbial risk assessment of Cryptosporidium
in soil and air samples. Int J Infect Dis 2014; 26:123-127.
Dado D, Izquierdo F, Vera O, Montoya A, Mateo M, Fenoy S, et al.
Detection of zoonotic intestinal parasites in public parks of Spain. Potential epidemiological role of Microsporidia
. Zoonoses Public Health 2012; 59:23-28.
Mandarino-Pereira A, de Souza FS, Lopes CW, Pereira MJ. Prevalence of parasites in soil and dog feces according to diagnostic tests. Vet Parasitol 2010; 170:176-181.
Mohaghegh MA, Jafari R, Ghomashlooyan M, Mirzaei F, Azami M, Falahati M, et al.
Soil contamination with oocysts of Cryptosporidium
spp. in Isfahan, central Iran. Int J Enteric Pathog 2015; 3:e29105.
Azami M, Sharifi M, Hejazi SH, Tazhibi M. Intestinal parasitic infections in renal transplant recipients. Braz J Infect Dis 2010; 14:15-18.
Kang G, Sarkar R, Desai NT. Cryptosporidiosis: an under-recognized public health problem. Trop Parasitol 2012; 2:91-98.
Okyay P, Ertug S, Gultekin B, Onen O, Beser E. Intestinal parasites prevalence and related factors in school children, a western city sample-Turkey. BMC Public Health 2004; 4:64.
Sayyari A, Imanzadeh F, Bagheri Yazdi S, Karami H, Yaghoobi M.
Prevalence of intestinal parasitic infections in the Islamic Republic of Iran. East Mediterr Health J 2005; 11:377-383.
Vojdani M, Barzeghar A, Shamsian A. A study of intestinal parasites among patients treated at the Kermansha Medical University clinic. J Kermansha Univ Med Sci 2002; 81:31-38.
Jafari R, Fallah M, Yousofi Darani H, Yousefi HA, Mohaghegh MA, Latifi M, et al.
Prevalence of intestinal parasitic infections among rural inhabitants of Hamadan city, Iran, 2012 Avicenna J Clin Microbiol Infect 2014; 1:e21445.
Fayer R, Leek R. The effects of reducing conditions, medium, pH, temperature, and time on in vitro
excystation of Cryptosporidium
. J Protozool 1984; 31:567-569.
Javier EF, Avila CR, Ignacio SJ, Tanaka-Kido J, Vallejo O, Sterling CR. Cryptosporidium
infections in Mexican children: clinical, nutritional, enteropathogenic, and diagnostic evaluations. Am J Trop Med Hyg 1997; 56:254-257.
McNabb S, Hensel D, Welch D, Heijbel H, McKee G, Istre G. Comparison of sedimentation and flotation techniques for identification of Cryptosporidium
sp. oocysts in a large outbreak of human diarrhea. J Clin Microbiol 1985; 22:587-589.
DuPont HL, Chappell CL, Sterling CR, Okhuysen PC, Rose JB, Jakubowski W. The infectivity of Cryptosporidium parvum
in healthy volunteers. N Eng J Med 1995; 332:855-859.
Taherkhani H, Fallah M, Jadidian K, Vaziri S. A study on the prevalence of Cryptosporidium
in HIV positive patients. J Res Health Sci 2007; 7:20-24.
Mirzaei M. Prevalence of Cryptosporidium
sp. infection in diarrheic and non-diarrheic humans in Iran. Korean J Parasitol 2007; 45:133-137.
Mons C, Dumetre A, Gosselin S, Galliot C, Moulin L. Monitoring of Cryptosporidium
river contamination in Paris area. Water Res 2009; 43:211-217.
Barwick R, Mohammed H, White M, Bryant R. Prevalence of Giardia
spp. and Cryptosporidium
spp. on dairy farms in southeastern New York state. Prev Vet Med 2003; 59:1-11.
Mac Kenzie WR, Hoxie NJ, Proctor ME, Gradus MS, Blair KA, Peterson DE, et al.
A massive outbreak in Milwaukee of Cryptosporidium
infection transmitted through the public water supply. N Eng J Med 1994; 331:161-167.