Insect Pest Control Laboratory, Joint FAO/IAEA Programme of Nuclear Techniques in Food and Agriculture, International Atomic Energy Agency, P.O. Box 100, A-1400, Vienna, Austria.
Ecole National de l'Elevage et de la Santé Animale, 03 BP 7026, Ouagadougou 03, Burkina Faso.
BMC Microbiol. 2018 Nov 23;18(Suppl 1):153. doi: 10.1186/s12866-018-1287-4.
Tsetse flies are vectors of African trypanosomes, protozoan parasites that cause sleeping sickness (or human African trypanosomosis) in humans and nagana (or animal African trypanosomosis) in livestock. In addition to trypanosomes, four symbiotic bacteria Wigglesworthia glossinidia, Sodalis glossinidius, Wolbachia, Spiroplasma and one pathogen, the salivary gland hypertrophy virus (SGHV), have been reported in different tsetse species. We evaluated the prevalence and coinfection dynamics between Wolbachia, trypanosomes, and SGHV in four tsetse species (Glossina palpalis gambiensis, G. tachinoides, G. morsitans submorsitans, and G. medicorum) that were collected between 2008 and 2015 from 46 geographical locations in West Africa, i.e. Burkina Faso, Mali, Ghana, Guinea, and Senegal.
The results indicated an overall low prevalence of SGHV and Wolbachia and a high prevalence of trypanosomes in the sampled wild tsetse populations. The prevalence of all three infections varied among tsetse species and sample origin. The highest trypanosome prevalence was found in Glossina tachinoides (61.1%) from Ghana and in Glossina palpalis gambiensis (43.7%) from Senegal. The trypanosome prevalence in the four species from Burkina Faso was lower, i.e. 39.6% in Glossina medicorum, 18.08%; in Glossina morsitans submorsitans, 16.8%; in Glossina tachinoides and 10.5% in Glossina palpalis gambiensis. The trypanosome prevalence in Glossina palpalis gambiensis was lowest in Mali (6.9%) and Guinea (2.2%). The prevalence of SGHV and Wolbachia was very low irrespective of location or tsetse species with an average of 1.7% for SGHV and 1.0% for Wolbachia. In some cases, mixed infections with different trypanosome species were detected. The highest prevalence of coinfection was Trypanosoma vivax and other Trypanosoma species (9.5%) followed by coinfection of T. congolense with other trypanosomes (7.5%). The prevalence of coinfection of T. vivax and T. congolense was (1.0%) and no mixed infection of trypanosomes, SGHV and Wolbachia was detected.
The results indicated a high rate of trypanosome infection in tsetse wild populations in West African countries but lower infection rate of both Wolbachia and SGHV. Double or triple mixed trypanosome infections were found. In addition, mixed trypanosome and SGHV infections existed however no mixed infections of trypanosome and/or SGHV with Wolbachia were found.
采采蝇是非洲锥虫的传播媒介，这种原生动物寄生虫会导致人类昏睡病（或非洲人类锥虫病）和牲畜中的那加那病（或动物非洲锥虫病）。除了锥虫之外，在不同的采采蝇物种中还报告了四种共生细菌（Wigglesworthia glossinidia、Sodalis glossinidius、沃尔巴克氏体、Spiroplasma 和一种病原体唾液腺肥大病毒（SGHV））。我们评估了在 2008 年至 2015 年间从布基纳法索、马里、加纳、几内亚和塞内加尔的 46 个地理地点收集的 4 种采采蝇（冈比亚舌蝇、G. tachinoides、G. morsitans submorsitans 和 G. medicorum）中沃尔巴克氏体、锥虫和 SGHV 之间的流行率和合并感染动态。
结果表明，在采样的野生采采蝇种群中，SGHV 和沃尔巴克氏体的总体流行率较低，而锥虫的流行率较高。三种感染的流行率因采采蝇种类和样本来源而异。在加纳的 G. tachinoides（61.1%）和塞内加尔的 G. palpalis gambiensis（43.7%）中发现了最高的锥虫流行率。在布基纳法索的四种采采蝇中，锥虫的流行率较低，即 G. medicorum 为 39.6%，G. morsitans submorsitans 为 18.08%；G. tachinoides 为 16.8%；G. palpalis gambiensis 为 10.5%。在马里（6.9%）和几内亚（2.2%），G. palpalis gambiensis 中的锥虫流行率最低。SGHV 和沃尔巴克氏体的流行率非常低，无论位置或采采蝇种类如何，SGHV 的平均流行率为 1.7%，沃尔巴克氏体为 1.0%。在某些情况下，检测到不同锥虫物种的混合感染。最高的合并感染率是间日疟原虫和其他锥虫物种（9.5%），其次是刚果锥虫与其他锥虫的合并感染（7.5%）。间日疟原虫和刚果锥虫的合并感染率为（1.0%），未检测到锥虫、SGHV 和沃尔巴克氏体的混合感染。
结果表明，西非国家野生采采蝇种群中的锥虫感染率很高，但沃尔巴克氏体和 SGHV 的感染率较低。发现了双重或三重混合锥虫感染。此外，存在混合锥虫和 SGHV 感染，但未发现锥虫和/或 SGHV 与沃尔巴克氏体的混合感染。
