Schistosomiasis Japonica: Skin Hyperthermia Treatment

Introduction

Schistosomiasis or bilharzia, is a common parasitic disease which can cause bladder dysfunction and hematuria, and even correlate with bladder cancer and increase HIV susceptibility with urogenital lesions.

Main Item

Schistosomiasis is an infection caused mainly by three schistosome species; Schistosoma mansoni, Schistosoma japonicum and Schistosoma haematobium. S. japonicum being the most infectious of the three species. Once the parasite has entered the body and begun to produce eggs, it uses the hosts' immune system (granulomas) for transportation of eggs into the gut. Individuals at risk to infection from S. japonicum are farmers who often wade in their irrigation water, fisherman that wade in streams and lakes, children that play in water, and people who wash clothes in streams.

Globally, it is estimated that more than 240 million people infected. Within endemic areas, children carry the heaviest burden of infection. Its treatment intensively depends on PZQ, which has replaced other antischistosomal drugs and become a regular first-line therapy. However, given that PZQ has been widely used for almost 40 years, the emergence of schistosomal resistance under drug selection pressure has received much attention.

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With the increase in schistosomiasis, the serious threat of PZQ resistance requires adequate monitoring of current mass drug administration programs. Thus, novel alternative intervention are in high demand and in this study we use hyperthermia to prevent and treat schistosomiasis as a result of its heat sensitivity.

High temperature has been used to treat illnesses dating back to as early as 5000 years ago.

Magnetic hyperthermia is currently a clinical therapy that is approved for treatment of tumor cells. Magnetic Hyperthermia is the name given to an experimental cancer treatment, although it has also been investigated for the treatment of other ailments, such as bacterial infections. It is based on the fact that magnetic nanoparticles, when subjected to an alternating magnetic field, produce heat. As a consequence, if magnetic nanoparticles are put inside a tumor and the whole patient is placed in an alternating magnetic field of well-chosen amplitude and frequency, the tumor temperature would rise.

Tumors can be shrunk by the effects of hyperthermia treatment, through the selective killing of cancer cells by damaging proteins and cellular structures. Recently, similar successful therapies have also been reported in treating acne vulgaris, mild-to-moderate inflammatory acne and cutaneous leishmaniasis.

A skin-hyperthermia device designed by Tsinghua university was applied for targeting migrating skin schistosomula and to expand on the in vitro findings on pre-treatment on cercariae, which is a novel method for treating the skin phase of a parasite infection.

The data obtained from the revealed that with the thermal dosages increased, the survival rate of cercariae decreased from 70% to 0% which indicated the preventing effect of hyperthermia (P < 0.05). When treated with thermal dosages above 45 Degrees C, the survival rate of cercariae ranged from a 50%. reduction to almost 100% compared with control groups. Moreover, when the S. japonicum infected mice was treated by heating the cercarial-contact region of skin, the worm reduction rates (WRR) reached 83.1% (P < 0.05).

The sensitivity of adult schistosomes to heat was also investigated by a microwave hyperthermia device (Figure 2A). The WRR, hepatic shift rates and egg reduction rates were 23.7%, 40% and 30% respectively after treated with thermal dosages of 42-43 Degrees C for 20 min. Although it was failed to exceed the group of PZQ, encouraging results have been obtained that hyperthermia could be an effective preventing method.

"To the best of our knowledge," wrote the researchers, "This work by far the first report that applying hyperthermia therapy in Schistosoma japonicum cercariae and skin-phase schistosomula. It apply the novel low-cost, convenient and non-toxic method as soon as possible after the appearance of cercarial dermatitis, which can have early

References

This research was funded by the Bill & Melinda Gates Foundation (Grant no: 1024516)

YANG Huixia , TANG Tao, HE Pei, ZHANG Youren, XIE Le, LIU Guangqi, LI Li, KONG Weichao, LI Jingdingsha, LIU Ruiting, LI Yukun, HU Junjian, WANG Xiaowen, LI Liya, XIANG Guanghong , GOBERT Geoffrey , LI Yuesheng, TANG Jintian. A novel and effective hyperthermia method for Schistosomiasis japonica prevention and treatment, Science Bulletin, 2015, 60(16): 1461-1464.

• scibull.com:8080/EN/Y2015/V60/I16/1461
• link.springer.com/article/10.1007%2Fs11434-015-0867-z

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This quality-reviewed publication was selected for publishing by the editors of Disabled World (DW) due to its significant relevance to the disability community. Originally authored by Science China Press, and published on 2015/10/14 (Edit Update: 2021/06/27), the content may have been edited for style, clarity, or brevity. For further details or clarifications, Science China Press can be contacted at scichina.com. NOTE: Disabled World does not provide any warranties or endorsements related to this article.