According to WHO report, Schistosomiasis is the second leading cause of death in parasitic infections after malaria [16]. Among the species of Schistosoma, the widest geographical distribution is related to the S. haematobium. The many of the Saharan and sub-saharan countries in Africa continent are infected.
Schistosomiasis control programs have been implemented or are being implemented in many African and Asian countries with varying success rates. Most of these control programs are based on the control of snail population, diagnosis and treatment of the infected persons, construction of hygienic latrines and public health education. In Senegal (west Africa), there is both Schistosoma mansoni and S.hematobium contamination in river areas, and the scope of contamination has increased with the creation of agricultural dams [17]. Until 2009, no major measures have been taken to control schistosomiasis in this country [18]. In 2009, the Schistosoma control program started by Programmed National de Lutte contre les Bilharzioses” (PNLB) in collaboration with WHO. At the beginning of the program, the rate of infection of Schistosoma mansoni and Schistosoma haematobium was estimated at 61% and 50% respectively. The control program was based on the evaluation of the level of contamination in school children, the construction of a hospital and diagnostic laboratory, the treatment of school children, the construction of sanitary latrines, public health education and annual monitoring of disease prevalence. The results of the Schistosoma control program in 2013 showed that the infection rate in school children decreased to 1.35% and in 2014, it reached 3.22% with a slight increase due to the some lack of acceptance of the drug [19].
The rate of Schistosoma infection in Kenya increased from 48–100% between 1977 until 1995 [20]. Kenya (East Africa) is considered as an endemic region for both intestinal and urinary schistosomiases. In 2011, the Kenyan government started a program to combat helminthic diseases in school children. Fifteen cities out of 45 cities in Kenya were covered by the treatment with praziquantel and until 2014 nearly 500,000 people were treated. The rate of contamination was estimated at 10.2 million people out of a population of 44.5 million [21]. Before this action, in the years between 1983–1988, in a five-year period, 2,219 rice farmers were given health measures, including health education, training water contact behaviors, improvement of water resources, construction of sanitary latrines, and mass chemotherapy with Praziquantel, which caused a significant reduction in percentage and intensity of the infection [22]. But considering that it was done at a very small level, it could not reduce schistosomiasis in the country. Without control of vector snail population through biological (using of crayfish) and chemical control, we cannot expect a sustainable reduction and control of the disease. Currently, Kenya with 100% populations at risk and 23% prevalence is considered one of the infected countries [21].
Egypt in North Africa was considered one of the most important infected areas in the world. Examining mummy bodies shows that this disease has existed since 5000 years ago [23]. The first control measures started in 1915. In 1918, it was considered the first country in the world to use antimony compounds for human treatment and copper sulfate to control the population of snails [24]. With the increase of dams and irrigation systems, the snail population and disease increased in 1930. Studies show that with the increase of dam construction, the rate of schistosomiasis infection reached from 2–11% to 44–75% [25]. With the implementation of a strict control program in the 20th century, the amount of pollution decreased from 40% in the first half of the 20th century to less than 0.3% in 2010. The control program included the use of crabs to biologically reduce the population of vector snails and reduce the rate of disease transmission, chemotherapy with Praziquantel (10 million school students), active identification of patients, and public health education. Despite the existence of small foci of the disease in Egypt, but the disease is 100% under control.
In Iraq a west neighbor of Iran, urinary schistosomiasis was first reported in 1899. In 1977, the level of infection in the areas between Tigris and Euphrates was announced as 20% [26]. This contamination was observed especially in rice farmers of the Euphrates River. The level of contamination in school children was different according to religion, it was reported 57% in Muslims, 30% in Christians and 27% in Jews [27]. The first action was carried out in 1952 based on the identification of patients, treatment of infected person and the control of intermediate snails population in irrigation systems and canals. As a result of control measures, the prevalence of the disease decreased significantly [28]. The snail control program was carried out by the composition of sodium pentachloride with the financial support of WHO until 1964 [29]. The rate of contamination decreased from 90% in 1960 to 5.3% in 1973, and at this time, the rate of contamination in preschool children went from 60–0%. The rate of contamination of fields with snails decreased from 42% in 1958 to 1.5% in 1980 [30]. The prevalence of the disease has reached 0.1% in 2010, and according to the WHO report in 2013, no one in Iraq needs schistosomiasis treatment and the disease is completely under control [15].
In this study, 4 samples out of 400 samples of Bulinus snails had furcocercous cercaria, but the PCR results did not belong to Schistosoma haematobium. Probably, the observed furcocercous could be related to S.bovis or S.nasalis in buffaloes because the infected snails with Schistosoma furcocercous were isolated from Gaumish Abad region, which is a place of buffalo breeding.