Betancourt Walter Q, Duarte Diana C, Vásquez Rosa C, Gurian Patrick L
Laboratory of Environmental Microbiology, Microbiology and Cell Biology Center, Venezuelan Institute for Scientific Research, Km 11 Carretera Panamericana, Caracas 1020A, Venezuela.
Laboratory of Environmental Microbiology, Microbiology and Cell Biology Center, Venezuelan Institute for Scientific Research, Km 11 Carretera Panamericana, Caracas 1020A, Venezuela.
Mar Pollut Bull. 2014 Aug 15;85(1):268-73. doi: 10.1016/j.marpolbul.2014.05.059. Epub 2014 Jun 26.
Sewage is a major contributor to pollution problems involving human pathogens in tropical coastal areas. This study investigated the occurrence of intestinal protozoan parasites (Giardia and Cryptosporidium) in tropical recreational marine waters contaminated with sewage. The potential risks of Cryptosporidium and Giardia infection from recreational water exposure were estimated from the levels of viable (oo) cysts (DIC+, DAPI+, PI-) found in near-shore swimming areas using an exponential dose response model. A Monte Carlo uncertainty analysis was performed in order to determine the probability distribution of risks. Microbial indicators of recreational water quality (enterococci, Clostridium perfringens) and genetic markers of sewage pollution (human-specific Bacteroidales marker [HF183] and Clostridium coccoides) were simultaneously evaluated in order to estimate the extent of water quality deterioration associated with human wastes. The study revealed the potential risk of parasite infections via primary contact with tropical marine waters contaminated with sewage; higher risk estimates for Giardia than for Cryptosporidium were found. Mean risks estimated by Monte Carlo were below the U.S. EPA upper bound on recreational risk of 0.036 for cryptosporidiosis and giardiasis for both children and adults. However, 95th percentile estimates for giardiasis for children exceeded the 0.036 level. Environmental surveillance of microbial pathogens is crucial in order to control and eradicate the effects that increasing anthropogenic impacts have on marine ecosystems and human health.
污水是热带沿海地区涉及人类病原体的污染问题的主要促成因素。本研究调查了受污水污染的热带休闲海水域中肠道原生动物寄生虫（贾第虫和隐孢子虫）的出现情况。利用指数剂量反应模型，根据在近岸游泳区域发现的活（卵）囊（DIC +、DAPI +、PI -）水平，估算了因接触休闲用水而感染隐孢子虫和贾第虫的潜在风险。进行了蒙特卡洛不确定性分析，以确定风险的概率分布。同时评估了休闲用水水质的微生物指标（肠球菌、产气荚膜梭菌）和污水污染的基因标记（人类特异性拟杆菌标记物[HF183]和球形梭菌），以估计与人类废物相关的水质恶化程度。该研究揭示了通过初次接触受污水污染的热带海水而感染寄生虫的潜在风险；发现贾第虫的风险估计高于隐孢子虫。蒙特卡洛估计的平均风险低于美国环境保护局（EPA）对儿童和成人隐孢子虫病和贾第虫病休闲风险设定的上限0.036。然而，儿童贾第虫病的第95百分位数估计超过了0.036这一水平。对微生物病原体进行环境监测对于控制和消除日益增加的人为影响对海洋生态系统和人类健康所产生的影响至关重要。
