There is an important relationship between trace elements and parasite infection. Many parasites can reduce the levels of trace elements of host, such as Se [10]. The body needs more trace elements while combating a parasite infection. Echinococcus cysts also absorb trace elements from the host to support their growth and development. Therefore, the serum level of Se and VA of an echinococciasis patient will be lower than in echinococcus cyst fluid[11, 12].. This interdependency may support a possible cure for parasitic disease.
In this study, the data of 89 echinococciasis patients in Aba and Garze Tibetan Autonomous Prefecture of Sichuan province were analyzed. The male to female ratio of the cases was 1:1.97 and gender is a known risk factor for infection [3, 8]. This known risk factor is often explained by cultural economic production habits, as women are often engaged in animal raising and the upkeep of the home increasing their exposure of the echinococcus cyst via infected dogs and livestock[3, 8].
The echinococciasis patients were mainly adults (58%) where the controls skewed towards a lower age range. Age is a known risk factor for echinococcus infection[3, 8]..Adults have more opportunity to be infected with echinococcus cyst while in productive activities. Due to the lack of early diagnosis of echinococciasis, young cases infected with echinococcus cyst are rarer. Most studies lack data on infections in children[13] while ours was able to account for their inclusion.
In this study, the serum levels of Se and VA of the echinococciasis patients were significantly downregulated compared with the healthy people, which was consistent with the result of a previous study13]. Animal studies also show similar results in the decline of VA in hydatid infected specimens [14]. Sufficient damage to the liver, due to the number and type of parasites, can cause acute and chronic hepatic insufficiency influencing the digestion, absorption, or metabolism of trace elements. Furthermore, progressive liver disease results in noted depletion of hepatic retinoid and VA content in humans[15].
The results suggest that Se and/or VA may be important trace elements for the treatment and prevention of echinococciasis. The change of trace elements might be due to host resistance to the ehcinococcus cyst or the growth of echinococcus cyst by absorbing trace elements. Research about the relationship between the trace elements and echinococciasis are limited especially in humans. Further studies are needed to delineate the role of trace elements in the survival, growth, and development of the echinococcus cyst. Also, research should clarify how the increase of trace elements in the host may prevent and/or treat echinococciasis. The influence of trace elements on host immune function is unknown. Furthermore, studies on the standard levels of trace elements in varying populations would assist in future evaluations.