Competence of Aedes aegypti, Ae. albopictus, and Culex quinquefasciatus Mosquitoes as Zika Virus Vectors, China

Abstract

In China, the prevention and control of Zika virus disease has been a public health threat since the first imported case was reported in February 2016. To determine the vector competence of potential vector mosquito species, we experimentally infected Aedes aegypti, Ae. albopictus, and Culex quinquefasciatus mosquitoes and determined infection rates, dissemination rates, and transmission rates. We found the highest vector competence for the imported Zika virus in Ae. aegypti mosquitoes, some susceptibility of Ae. albopictus mosquitoes, but no transmission ability for Cx. quinquefasciatus mosquitoes. Considering that, in China, Ae. albopictus mosquitoes are widely distributed but Ae. aegypti mosquito distribution is limited, Ae. albopictus mosquitoes are a potential primary vector for Zika virus and should be targeted in vector control strategies.

Keywords: Aedes aegypti; Aedes albopictus; China; Culex quinquefasciatus; Zika virus; mosquitoes; vector competence; vector-borne infections; viruses.

Figure 1

Infection rates and virus reproduction for Zika virus in Aedes aegypti, Ae. albopictus, and Culex quinquefasciatus mosquitoes in China. A) Infection rate. Error bars represent 95% CIs. **, p<0.01. B) Zika virus RNA titers in the whole mosquito bodies was detected by quantitative reverse transcription PCR. The results are expressed as mean ± SD.

Figure 2

Vector competence of Zika virus in Aedes aegypti, Ae. albopictus, and Culex quinquefasciatus mosquitoes in China. The midguts, heads, and salivary glands from mosquitoes of the 3 species were dissected at 0, 4, 7, 10, and 14 days after infection, and Zika virus was detected by reverse transcription PCR. A) Infection rate (no. positive midguts/total no. midguts). B) Dissemination rate (no. positive heads/no. positive midguts). C) Transmission rate (no. positive salivary glands/no. positive midguts). Error bars indicate 95% CIs. *p<0.05; **p<0.01.

Figure 3

Zika virus RNA copies in infected midguts (A), heads (B), and salivary glands (C) of Aedes aegypti, Ae. albopictus, and Culex quinquefasciatus mosquitoes in China. Results are expressed as means ± SD. Dotted lines indicate the level below which minimum value could not fall. Error bars indicate SDs.