Soil contamination with ascarid eggs in playgrounds in Kirikkale, Turkey

Pathogenic parasites in sewage irrigated crops and soil: pattern of occurrence and health implications

The current study aimed to determine the contamination level by human parasite eggs and cysts of sewage-irrigated soil, food crops and fodder crops. Field trials were conducted on spray-irrigated lettuce and flood-irrigated crops using raw wastewater and fresh water. Findings showed that irrigation by raw wastewater led to crops contamination with parasite eggs and cysts in varying levels. Lettuce samples were positive (27.7%) for one or more helminth eggs including the pathogens Ascaris and Trichuris with an average of 4.7 eggs/kg. Wastewater application caused an increase in lettuce contamination, followed by a decreasing phase. Cessation of irrigation resulted in helminth eggs disappearance within a week. Flood-irrigated crops were contaminated with helminth eggs in levels ranging from 1.5 eggs/kg in alfalfa to 4.75 eggs/kg in coriander. The pathogenic Giardia,Entamoeba histolytica/dispar and commensal amoeba cysts were highly detected reaching 9.97x103 cysts/kg in alfalfa. Parasites highly concentrated in soil, with levels up to 159 eggs/100gdw and 1.3x103 cysts/gdw. Ascaris and Trichuris eggs developed in soil and crops attaining the infective stage. Crops and soil irrigated with fresh water were free from parasite eggs and cysts. The occurrence of pathogens in soil and crops implies health risks for farmers, produce handlers and consumers.

The survival and dispersal of Taenia eggs in the environment: what are the implications for transmission? A systematic review

Taenia spp. are responsible for a substantial health and economic burden in affected populations. Knowledge of the fate of the eggs of Taenia spp. in the environment and of other factors facilitating the transmission of eggs to intermediate hosts is important for the control/elimination of infections caused by Taenia spp. The aim of this systematic review was to summarize current knowledge of the factors influencing the survival and dispersal of Taenia spp. eggs in the environment. Publications retrieved from international databases were systematically reviewed. Of the 1465 papers initially identified, data were ultimately extracted from 93 papers. The results of this systematic review indicate that survival is favoured at moderate temperatures (0–20 °C). Humidity seems to affect the survival of Taenia spp. eggs more than temperature. Under field circumstances, Taenia spp. eggs have been found to survive for up to 1 year. Taenia spp. eggs are commonly found on vegetables (0.9–30%) and in soil and water samples (0–43%), with their presence posing a risk to the consumer. Invertebrates may act as transport hosts, transferring the infection to an intermediate host, but the importance of this route of transmission is still open to question. Wastewater treatment systems are not capable of entirely eliminating Taenia spp. eggs. Access to surface water and the use of sewage sludge as fertilizer on pastures are important risk factors for bovine cysticercosis. Although information on the survival and spread of Taenia spp. eggs is available, in general the data retrieved and reviewed in this article were old, focused on very specific geographical regions and may not be relevant for other areas or not specific for different Taenia spp. Furthermore, it is unknown whether egg survival differs according to Taenia sp. Future studies are necessary to identify sustainable methods to identify and inactivate parasite eggs in the environment and reduce their spread.

Soil and Sand Contamination with Canine Intestinal Parasite Eggs as a Risk Factor for Human Health in Public Parks in Niš (Serbia)

Regarding geographical distribution and clinical relevance, the most common canine geohelminths are Toxocara canis, ancylostomatids, and Trichuris vulpis. Canine intestinal parasites from the soil and sand present an important potential serious human health hazard, especially for the children preschool and school - age. This paper aimed to establish the degree of contamination of soil and sand with zoonotic parasites from the canine feces and the degree of risk they could pose for human health in public places and playgrounds in the city of Niš. Our parasitological study involved 200 soil samples and 50 sand samples from the public parks in the city of Niš in southeastern Serbia (43°19'15″N, 21°53'45″ E). From several locations, about 100 g of soil and sand was collected based on the bioclimatic indices. Parasitological diagnosis was performed using conventional qualitative and quantitative coprological methods, abiding by the recommendations about the diagnosis of parasitic diseases. In 38 - 46 % of soil samples and 40 % of sand samples seven species of endoparasites were diagnosed. In the samples of soil, a medium and high degree of contamination with the ascarid T. canis (14 - 22 %) was detected, as well as a low and medium degree of contamination with ancylostomatids (4 - 12 %), and in the samples of sand, a variable degree of contamination with the helminths T. canis (26 %) and A. alata (16 %) was found. A statistically significant difference was found in the contamination with A. alata eggs between the samples of sand and samples of soil. The studied public surfaces represent the reservoir of zoonotic parasites, which is a public health problem requiring a synergistic action of several factors to be successfully resolved, i.e. the implementation of prevention, surveillance, and control measures.

Sources and seroprevalence of toxocariasis in Turkey

Toxocariasis in humans is considered a rare disease in Turkey, and the absence of specific symptoms of this disease is probably the main reason for clinicians to underestimate and underdiagnose the disease. Although there are several seroepidemiological studies on visceral larva migrans in the country, a comparison between them is difficult as the serological tests are not standardised. After the introduction of the easily accessible ELISA kit in the market, the number of seroepidemiological studies has increased in which the reported rates ranged between 1% and 56%. Similar to other countries, Toxocara seropositivity in Turkey is more common in men, childhood, in those living in rural area, having a low income level, owning dogs, and biting their nails or practicing geophagia. In addition, toxocariasis is a risk factor for veterinarians, farmers, and pet-shop workers. Toxocara seroprevalence is significantly higher in respiratory, neuropsychiatric, musculoskeletal, skin and abdominal disorders. There are also many studies showing the importance of eosinophilia in toxocariasis. In conclusion, although there are many studies on toxocariasis in Turkey, it is still not well understood to what extent the infection is responsible for a plethora ascribed symptoms. Standardisation of the diagnostic methods and the use of molecular techniques could further throw light in the real epidemiology and the role played by the infection to induce signs and symptoms.

Detection of Toxocara eggs in contaminated soil from various public places of Chennai city and detailed correlation with literature

Toxocarosis is one of the most prevalent human helminthosis caused by larvae of Toxocara canis and Toxocara cati, the most widely distributed nematode parasites of dogs and cats respectively. Soil is considered as the principal source of transmission of Toxocara infection to human beings. With increasing population of dogs and cats, soil contamination with ova or eggs of Toxocara can be detected in public and private locations of city backyards, playgrounds, streets, sand pits and so on, regardless of the season of the year. In this context the present study was carried out to estimate the extent of soil contamination with Toxocara eggs in public parks, playgrounds and few kennels situated in different parts of Chennai city. A total of 105 soil samples from 40 public places and 5 kennels were screened for the presence of parasitic eggs. Toxocara eggs were recovered from 5 soil samples indicating an overall prevalence rate of 4.75 %. Out of 80 samples collected from public places, three samples, one each from Mogappair, My lady park (Periamet) and Madras Veterinary College showed the presence of Toxocara spp. eggs indicating an overall prevalence of 3.75 per cent. Out of the 25 samples from 5 kennels, two samples one each from Tambaram and Thorappakkam kennels were positive for Toxocara eggs with prevalence of 8 per cent. Low prevalence of Toxocara eggs in soil samples of these areas can be attributed to the less population of pups, the carriers of adult worms and the active source of soil contamination. The progress made in ABC (animal birth control) programme carried out by both governmental and non-governmental organizations has contributed to reduction of birth rate in dogs and thereby reduced the chances of soil contamination with Toxocara eggs to a certain extent in Chennai city.

Contamination of public parks and squares from Guarulhos (São Paulo State, Brazil ) by Toxocara spp. and Ancylostoma spp

The contaminated soil with mammal feces is an important factor of risk to infection with zoonotic diseases. Amongst these zoonoses are visceral larva migrans and cutaneous larva migrans caused by Toxocara spp. and Ancylostoma spp., respectively. The aim of this study was to assess the environmental contamination by Toxocara spp. eggs and hookworms (Ancylostoma spp.) in public parks and squares in the city of Guarulhos, a metropolitan area of São Paulo, São Paulo State, Brazil. Soil samples were collected, between September and December 2010, and examined using the centrifugal flotation technique with sodium dichromate and zinc sulphate as well as the modified Baermann method. Notably, 35 (74.5%) of the 47 districts surveyed in Guarulhos possessed samples contaminated with Toxocara spp. and/or eggs or larvae of Ancylostoma spp. The frequency of Toxocara spp. and Ancylostoma spp. in the samples from public areas was 68.1% and 46.8%, respectively. Overall, the eastern side of Guarulhos is the region with the highest occurrence of causative agents of larva migrans. In all collection sites, the presence of feces from dogs and cats accompanied by their owners and stray animals were observed. Notably, it is important to adopt measures to control dog and cat breeding, to treat infected animals, and provide health education to the population.

Prevalence of canine toxocariasis in Bareilly, Uttar Pradesh, India

Toxocara canis is one of the most common parasitic helminth worm of dogs and also a causative agent of zoonotic disease in humans. This pilot study was conducted to determine the presence of T. canis infection in dog population in and around Bareilly, Uttar Pradesh, India. A total of 558 faecal samples both from stray and owned dogs were screened and overall 24.3 % dogs were found positive for T. canis. A comparison between owned and stray dogs suggests that the higher prevalence was observed in the latter group. The age of the dogs had a considerable influence on prevalence, with a much higher proportion of younger dogs being infected. Among the stray dogs, the infection rate is much higher (62.79 %) in pups, as compared to 7.8 % in adult. Similarly, of the owned dogs screened 41.74 % pups were infected while the infection rate in adults was only 3.38 %. The higher rate of prevalence of this parasite in dogs could be the source of soil contamination for transmission of Toxocariasis which is of public health importance in this region.

Inactivation of Ascaris eggs in soil by microwave treatment compared to UV and ozone treatment

This study reports on the effect of microwave radiation for inactivation of Ascaris lumbricoides eggs in 25 g of soil compared to ultraviolet irradiation and ozone expose. Microwave radiation at 700 W with 14% water content (w/w) achieved approximately 2.5 log inactivation of eggs in soil within 60s. On the other hand, UV irradiation at 3 mW cm(-2) with and without shaking soil for 3600 s achieved approximately 0.32 and 0.01 log inactivation of eggs, respectively. In ozone treatment, 0.13 log inactivation of eggs was achieved with 5.8+/-0.7 mg L(-1) of dissolved ozone dose for 30 min in a continuous diffusion reactor. In addition, the inactivation of eggs by three disinfection techniques was conducted in water in order to compare the inactivation efficiency of eggs in soil. The inactivation efficiency of microwave radiation was found to be no significant difference between in soil and water. However, the inactivation efficiency of UV irradiation was significantly increased in water while in ozone expose there was no significant difference between in soil and water. Microwave treatment thus proved to be the most efficient method in controlling A. lumbricoides eggs in soil.

Seasonal contamination of public squares and lawns by parasites with zoonotic potential in southern Brazil

The presence of helminths and protozoans in public squares and lawns of the city of Maringá, southern Brazil, during winter and summer was assessed in order to evaluate their seasonal fluctuations in relation to edaphic and climatic factors. Samples were collected from January 2003 through June 2004 in 90% (13) of all public squares covered by sand, and in 30% (4) of all lawns used as leisure areas. The samples were analysed quantitatively by modified centrifugal-flotation and sedimentation in water techniques, and qualitatively by a method based on positive larval thermo-hydrotropism. Meteorological data were recorded, and physical, chemical and structural characteristics of the soil were analysed. One hundred and thirty samples of sand from squares, 65 in summer and 65 in winter, and 40 samples of grass from lawns, 20 in each season, were collected. All samples from lawns, 62 (95.38%) from squares in winter and 45 (69.23%) in summer, contained protozoans and/or helminths. Eggs of Toxocara spp. were the most frequently observed parasites in both winter and summer in squares (P < 0.0001) and in lawns (P = 0.6142), being equally distributed among the different locations (P = 0.2038). Species diversity was lower in winter; fewer parasites were found in summer. This region, with a tropical climate and a mild winter dry season, has favourable edaphic and climatic conditions for soil contaminants to persist year-round. In addition, the high frequency of animals such as dogs and cats and the poor sanitary measures in force made it possible for zoonoses to be transmitted in the public spaces.

Prevalence of Toxocara spp., Toxascaris leonina and ancylostomidae in public parks and beaches in different climate zones of Costa Rica

This epidemiological study was conducted in different regions of Costa Rica to determine the prevalence of the developmental stages of potential zoonotic intestinal helminths of dogs and cats in public places. Samples were collected within three main climate zones including rural and urban areas during both the rainy and the dry season. Faecal and environmental samples were taken from 69 parks and beaches. Of the faecal samples 3% contained Toxascaris spp. eggs, 7% Toxocara spp. eggs and 55% contained ancylostomidae eggs. Of the soil samples, 2% contained ancylostomidae eggs and 0.8% contained ascarid eggs. Significant differences in the presence of parasites were found in faecal samples of dry, moist and wet climate zones and between the dry and rainy seasons. Significant differences in the presence of eggs and larvae were also found in the grass samples in the dry, the moist and the wet climate zones and between the different seasons. No significant differences were found between rural and urban areas.

Contamination of soil with Toxocara eggs in urban (Prague) and rural areas in the Czech Republic

Contamination of soil with feline and canine ascarid eggs in public parks, backyards and sand pits in Prague, Czech Republic was investigated in this work. Soil samples from shelters and rural areas were also collected. The comparison of soil from different areas (urban, rural, backyards and shelters) exhibited significant difference (chi(2)=32.16, d.f.=3 and p<0.0001). The highest rate of contamination (45%) was found in backyards inhabited by feral cats. The eggs of Toxocara spp. were found in 20.4% of parks, 10% of shelters and 5% of rural samples. Mean egg density per sample from Prague parks was 6.2 eggs/100g of soil. In 126 composite samples from children's and pits, the prevalence of Toxocara eggs was 11.90%. The number of eggs in positive samples varied from 2 to 22 (per 100g). A high proportion (46.9%) of eggs was fully embryonated. There was no difference between the sand pits with or without formal exclusion of dogs (chi(2)=0.6, d.f.=1 and p<0.0001).