Khowawisetsut Ladawan, Sarasombath Patsharaporn T, Thammapalo Suwich, Loymek Sumart, Korbarsa Therayot, Nochote Hathai, Phuakrod Achinya, Choochote Wej, Wongkamchai Sirichit
Department of Parasitology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand.
Office of Disease Prevention and Control Region 12 Songkhla, Department of Disease Control, Ministry of Public Health, Songkhla 90000, Thailand.
Vet Parasitol. 2017 Oct 15;245:42-47. doi: 10.1016/j.vetpar.2017.08.009. Epub 2017 Aug 18.
Lymphatic filariasis (LF) is one of the neglected tropical diseases which causes permanent and long term disability worldwide. LF is caused by filarial nematode parasites, i.e. Wuchereria bancrofti, Brugia malayi, and B. timori. All available antifilarial drugs currently being used have shown a limited adulticidal activity. Discoveries of endosymbiont rickettsia-like bacterium, Wolbachia in filarial nematodes provided a novel approach for antibiotic use in eradication of filarial diseases. The earlier studies revealed the macrofilaricidal efficacy of doxycycline against filarial nematodes. Chemotherapeutic efficiency of doxycycline has been studied against many filarial parasites, but there are still no therapeutic trials of the drug regimens for B. malayi treatment in naturally infected cats. Thus, this study would be the first attempt to study the efficiency of doxycycline (DOXY) alone or in combination with ivermectin (IVM) for treatment of B. malayi in naturally infected cats. A total of 26 B. malayi-infected cats in the endemic areas were recruited and divided into 3 groups, receiving different treatment regimens; a single dose of ivermectin only (IVM), doxycycline only (DOXY) and a combination of ivermectin and doxycycline (DOXY-IVM). The efficacy of each therapatic regimen was evaluated by detecting the presence of microfilaria using parasitological and molecular techniques monthly up to 2 years after starting the treatment. The IVM treated group had a significant rapid reduction of microfilariae in the first month; however, recurrence of microfilaraemia was observed in some cats. By contrast, the DOXY and DOXY-IVM groups showed a better result with a gradual decrease in microfilariae with no recurrence. These 2 groups were not only virtually deprived of infection but also sustained the sterility of infection through the course of study. These results revealed the advantages of using in B. malayi treatment in cats. Doxycycline showed to have both microfilaricidal and adulticidal effects on lymphatic filariae which maintained the long-term response to control of B. malayi infection in cats.
淋巴丝虫病（LF）是一种被忽视的热带疾病，在全球范围内导致永久性和长期残疾。LF由丝虫线虫寄生虫引起，即班氏吴策线虫、马来布鲁线虫和帝汶布鲁线虫。目前正在使用的所有抗丝虫药物的成虫杀灭活性都有限。在丝虫线虫中发现内共生立克次氏体样细菌沃尔巴克氏体，为使用抗生素根除丝虫病提供了一种新方法。早期研究揭示了强力霉素对丝虫线虫的杀成虫效果。已经研究了强力霉素对许多丝虫寄生虫的化疗效果，但对于自然感染猫的马来布鲁线虫治疗药物方案仍没有治疗试验。因此，本研究将是首次尝试研究单独使用强力霉素（DOXY）或与伊维菌素（IVM）联合使用治疗自然感染猫体内马来布鲁线虫的效果。总共招募了26只流行地区感染马来布鲁线虫的猫，并将它们分为3组，接受不同的治疗方案；仅单剂量伊维菌素（IVM）、仅强力霉素（DOXY）以及伊维菌素和强力霉素联合使用（DOXY-IVM）。在开始治疗后的2年内，每月使用寄生虫学和分子技术检测微丝蚴的存在，以评估每种治疗方案的疗效。IVM治疗组在第一个月微丝蚴显著快速减少；然而，在一些猫中观察到微丝蚴血症复发。相比之下，DOXY组和DOXY-IVM组显示出更好的结果，微丝蚴逐渐减少且无复发。这两组不仅几乎没有感染，而且在整个研究过程中保持了感染的无菌状态。这些结果揭示了在猫体内治疗马来布鲁线虫时使用这些药物的优势。强力霉素对淋巴丝虫显示出杀微丝蚴和杀成虫作用，可长期控制猫体内马来布鲁线虫感染。
