Schistosomiasis caused by Schistosoma japonicum is one of the most serious parasitic diseases and remains endemic to seven provinces of China. The highest prevalence rates (3.8%) were mainly in the lake and marshland regions. It is estimated that there are 726,112 human cases and the number of people at risk in endemic areas was 13,937,235. China is a nonendemic area for S haematobium infection. However, with the increase of the workers and tourists to endemic countries, schistosomiasis haematobium has made its entry as an imported disease. Even a single exposure (eg, from swimming, bathing, paddling, or rafting) can cause infection. At present, thousands of persons only from Henan Province are employed in building, water supply, and irrigation projects in Africa. Additionally, the number of travelers going to Africa has increased along with the increase in income and development of tourism. It is estimated that some of the people returning from Africa might be infected with S haematobium and the infected patients probably remain undiagnosed, because schistosomiasis haematobium is rare in China, and the patients and their physicians are unfamiliar with its clinical manifestations and unaware of the possibility of schistosomiasis. Hence, this imported disease may be neglected, undiagnosed, or misdiagnosed. The delay in diagnosis will put these patients at risk of complications, even development of bladder cancer. The reported two patients received inappropriate treatment for 6 months. Additionally, an American patient with loiasis presented with migratory facial edema 21 years after visiting an endemic area in Africa for only 4 days, and was misdiagnosed as “suspicious for lymphoma” for 2 years. Furthermore, during this period of time, the patients were potentially at risk of contaminating the environment; thus, the parasitic disease imported from Africa might be introduced into China and could spread in the case of presence of appropriate intermediate snail hosts. In the event of this happening, control and elimination of schistosomiasis in China would become more complicated and difficult.
The emergence and misdiagnosis of S haematobium infection is the consequence of poor knowledge of African diseases in China. These two cases indicated the gaps in knowledge and awareness among the general public and authorities of the risk of schistosomiasis from freshwater exposure in Africa. Heath education is the prerequisite of all preventive measures for S haematobium infection. Comprehensive public health education to avoid exposure to contaminated freshwater should be provided to all travelers going to endemic areas. Before workers are sent to Africa, the international labor export companies and public health authorities should adopt a clear policy outlining the risk of schistosomiasis and forbidding exposure to freshwater through swimming, bathing, washing, paddling, and so on. They should also provide appropriate information materials to communicate the risks of exposure to any fresh, untreated water in all the endemic areas of schistosomiasis, specifically targeting the high-risk workers. Besides, the physicians and urologists should be aware of schistosomiasis, and urine microscopy of S haematobium eggs by centrifugation or sedimentation should be carried out as early as possible whenever patients with visible hematuria have a history of working or traveling in endemic countries.