Abstract：
BACKGROUND: Several hypotheses have been proposed for explaining the outbreak of coronavirus disease 2019 (COVID-19)-associated mucormycosis in India, including the burning of cattle dung cakes, though no study has yet been conducted to support this claim.
METHODS: We conducted an aero-mycological study to evaluate whether Mucorales in the air increased during or after burning cattle dung cakes. We further compared the growth of Mucorales in the indoor air samples from houses with and without cattle. We also cultured fresh and dried cattle dung and soil samples for Mucorales.
RESULTS: We noted no significant difference in the proportion of air samples growing Mucorales during (4/22 [18.2%]) and after (3/2 [13.6%]) cattle dung burning than that collected immediately before (4/22 [18.2%]). Mucorales were isolated in 15.4% of the indoor air samples obtained from different houses (both rural and urban); the proportion of samples growing Mucorales was not significantly different in households with and without cattle. We also observed growth of Mucorales in 6 of the 8 [75%] fresh and 3 of the 6 [50%] dried dung samples. The most common Mucorales isolated from soil and dung samples was Lichtheimia corymbifera, while Rhizopus arrhizus was the most common species isolated from indoor air samples.
CONCLUSIONS: We found no significant increase in the proportion of air samples growing Mucorales during or after burning cattle dung cake than that before. It seems unlikely that cattle dung burning contributes to the occurrence of mucormycosis.
METHODS: We conducted an aero-mycological study to evaluate whether Mucorales in the air increased during or after burning cattle dung cakes. We further compared the growth of Mucorales in the indoor air samples from houses with and without cattle. We also cultured fresh and dried cattle dung and soil samples for Mucorales.
RESULTS: We noted no significant difference in the proportion of air samples growing Mucorales during (4/22 [18.2%]) and after (3/2 [13.6%]) cattle dung burning than that collected immediately before (4/22 [18.2%]). Mucorales were isolated in 15.4% of the indoor air samples obtained from different houses (both rural and urban); the proportion of samples growing Mucorales was not significantly different in households with and without cattle. We also observed growth of Mucorales in 6 of the 8 [75%] fresh and 3 of the 6 [50%] dried dung samples. The most common Mucorales isolated from soil and dung samples was Lichtheimia corymbifera, while Rhizopus arrhizus was the most common species isolated from indoor air samples.
CONCLUSIONS: We found no significant increase in the proportion of air samples growing Mucorales during or after burning cattle dung cake than that before. It seems unlikely that cattle dung burning contributes to the occurrence of mucormycosis.
摘要：
背景：已经提出了几个假设来解释印度2019年冠状病毒病（COVID-19）相关毛霉菌病的爆发，包括焚烧牛粪饼，尽管尚未进行任何研究来支持这一说法。
方法：我们进行了一项空气真菌学研究，以评估燃烧牛粪饼期间或之后空气中的Mucorales是否增加。我们进一步比较了有牛和没有牛的房屋的室内空气样本中Mucorales的生长。我们还为Mucorales培养了新鲜和干燥的牛粪和土壤样本。
结果：我们注意到在（4/22[18.2％]）和（3/2[13.6％]）牛粪燃烧期间（4/22[18.2％]）和之前收集的空气样本中生长Mucorales的比例没有显着差异。从不同房屋（农村和城市）获得的室内空气样本中，有15.4％分离出了Mucorales；在有牛和没有牛的家庭中，种植Mucorales的样品比例没有显着差异。我们还在8个[75%]新鲜粪便样品中的6个和6个[50%]干燥粪便样品中的3个中观察到了Mucorales的生长。从土壤和粪便样本中分离出的最常见的毛霉菌是紫草，而阿氏根霉是从室内空气样本中分离出的最常见的物种。
结论：我们发现在燃烧牛粪饼期间或之后，空气样品中生长Mucorales的比例没有显着增加。牛粪燃烧似乎不太可能导致毛霉菌病的发生。
方法：我们进行了一项空气真菌学研究，以评估燃烧牛粪饼期间或之后空气中的Mucorales是否增加。我们进一步比较了有牛和没有牛的房屋的室内空气样本中Mucorales的生长。我们还为Mucorales培养了新鲜和干燥的牛粪和土壤样本。
结果：我们注意到在（4/22[18.2％]）和（3/2[13.6％]）牛粪燃烧期间（4/22[18.2％]）和之前收集的空气样本中生长Mucorales的比例没有显着差异。从不同房屋（农村和城市）获得的室内空气样本中，有15.4％分离出了Mucorales；在有牛和没有牛的家庭中，种植Mucorales的样品比例没有显着差异。我们还在8个[75%]新鲜粪便样品中的6个和6个[50%]干燥粪便样品中的3个中观察到了Mucorales的生长。从土壤和粪便样本中分离出的最常见的毛霉菌是紫草，而阿氏根霉是从室内空气样本中分离出的最常见的物种。
结论：我们发现在燃烧牛粪饼期间或之后，空气样品中生长Mucorales的比例没有显着增加。牛粪燃烧似乎不太可能导致毛霉菌病的发生。
