Seasonality and transmissibility of Plasmodium ovale in Bagamoyo District, Tanzania.
Seasonality and transmissibility of Plasmodium ovale in Bagamoyo District, Tanzania.
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DOI：
10.1186/s13071-022-05181-2
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发表时间：
2022-02-14
影响因子：
3.2
通讯作者：
Mathias DK
中科院分区：
文献类型：
--
作者：
Tarimo BB;Nyasembe VO;Ngasala B;Basham C;Rutagi IJ;Muller M;Chhetri SB;Rubinstein R;Juliano JJ;Loya M;Dinglasan RR;Lin JT;Mathias DK
卵形疟原虫是一种被忽视的疟疾寄生虫，可在人的肝脏中形成潜伏的催眠虫。在过去十年中，非洲非恶性疟疾的分子监测研究强调，卵圆疟原虫在雷达下传播，包括恶性疟原虫下降的地区。为了消除流行卵形疟原虫的疟疾，需要更好地了解其流行病学、无症状携带和传播生物学。我们进行了一项卵形疟原虫传播的试点研究，作为正在进行的恶性疟原虫从无症状携带者到蚊子的传播研究的一部分。为了确定疟疾无症状水库的特征，在坦桑尼亚巴加莫约三个传播季节进行了横断面qPCR调查。采用冈比亚按蚊（IFAKARA株）直接皮肤摄食法（dfa）对阳性个体进行恶性疟原虫传播研究。对于在DFA当天卵形疟原虫筛查呈阳性的一部分参与者，我们将血液喂养的蚊子孵育14天，以评估孢子体的发育情况。对无症状个体的分子监测显示卵形疟原虫的患病率为11%(300/2718)，而恶性疟原虫的患病率为29%（780/2718）。卵圆疟原虫在长雨季开始时患病率最高（15.5%,128/826），而恶性疟原虫在长雨季和短雨季均较晚达到峰值。考虑到这些早季卵形疟原虫感染是低密度的单一感染（127/128），我们推测许多是由于催眠子石诱导的复发。接受dfa治疗的8名无症状卵圆疟原虫感染者中有6名成功地将卵圆疟原虫传播给冈比亚疟蚊。在坦桑尼亚沿海地区，卵圆形疟原虫在无症状个体中以4-15%的流行率传播，现场诊断基本上看不到。与共同流行的恶性疟原虫不同的季节高峰、复发的能力以及向按蚊媒介的有效传播可能是其在集中防治恶性疟原虫的努力中持续存在的原因。
Plasmodium ovale is a neglected malarial parasite that can form latent hypnozoites in the human liver. Over the last decade, molecular surveillance studies of non-falciparum malaria in Africa have highlighted that P. ovale is circulating below the radar, including areas where Plasmodium falciparum is in decline. To eliminate malaria where P. ovale is endemic, a better understanding of its epidemiology, asymptomatic carriage, and transmission biology is needed. We performed a pilot study on P. ovale transmission as part of an ongoing study of human-to-mosquito transmission of P. falciparum from asymptomatic carriers. To characterize the malaria asymptomatic reservoir, cross-sectional qPCR surveys were conducted in Bagamoyo, Tanzania, over three transmission seasons. Positive individuals were enrolled in transmission studies of P. falciparum using direct skin feeding assays (DFAs) with Anopheles gambiae s.s. (IFAKARA strain) mosquitoes. For a subset of participants who screened positive for P. ovale on the day of DFA, we incubated blood-fed mosquitoes for 14 days to assess sporozoite development. Molecular surveillance of asymptomatic individuals revealed a P. ovale prevalence of 11% (300/2718), compared to 29% (780/2718) for P. falciparum. Prevalence for P. ovale was highest at the beginning of the long rainy season (15.5%, 128/826) in contrast to P. falciparum, which peaked later in both the long and short rainy seasons. Considering that these early-season P. ovale infections were low-density mono-infections (127/128), we speculate many were due to hypnozoite-induced relapse. Six of eight P. ovale-infected asymptomatic individuals who underwent DFAs successfully transmitted P. ovale parasites to A. gambiae. Plasmodium ovale is circulating at 4–15% prevalence among asymptomatic individuals in coastal Tanzania, largely invisible to field diagnostics. A different seasonal peak from co-endemic P. falciparum, the capacity to relapse, and efficient transmission to Anopheles vectors likely contribute to its persistence amid control efforts focused on P. falciparum.
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影响因子：
3.8
作者：
Yman, Victor;Wandell, Grace;Farnert, Anna
通讯作者：
Farnert, Anna
影响因子：
11.8
作者：
Groger, Miriam;Veletzky, Luzia;Ramhartert, Michael
通讯作者：
Ramhartert, Michael
影响因子：
3
作者：
Knols, Bart G.J.;Njiru, Basilio N.;Killeen, Gerry F.
通讯作者：
Killeen, Gerry F.
DOI：
10.1016/s2666-5247(21)00009-4
发表时间：
2021-04
期刊：
The Lancet. Microbe
影响因子：
--
作者：
Akala HM;Watson OJ;Mitei KK;Juma DW;Verity R;Ingasia LA;Opot BH;Okoth RO;Chemwor GC;Juma JA;Mwakio EW;Brazeau N;Cheruiyot AC;Yeda RA;Maraka MN;Okello CO;Kateete DP;Managbanag JR;Andagalu B;Ogutu BR;Kamau E
通讯作者：
Kamau E
影响因子：
3.8
作者：
Ross A;Koepfli C;Schoepflin S;Timinao L;Siba P;Smith T;Mueller I;Felger I;Tanner M
通讯作者：
Tanner M