Evidence of Zika virus horizontal and vertical transmission in Aedes albopictus from Spain but not infectious virus in saliva of the progeny

Figures & data

Table 1. Summary of vector competence assays.

				Number of mosquitoes tested per time point
Mosquito species tested	Population	ZIKV strains tested	Titer of ZIKV (TCID 50/ml)	7 dpe^a	14 dpe^a	21 dpe^a	Total
Ae. albopictus	El Prat de Llobregat	Martinique	7 log10 TCID50/ml	20	20	17	57
	El Prat de Llobregat	Dak84	7 log10 TCID50/ml	11	13	12	36
Ae. albopictus	Rubí	Martinique	7 log10 TCID50/ml	28	27	22	77
	Rubí	Dak84	7 log10 TCID50/ml	28	27	25	80

^a Dpe: days post-exposure.

Figure 1. Infection, dissemination and transmission rates and transmission efficiency of two field-collected Ae. albopictus populations exposed to Dakar and Martinique ZIKV strains, which are represented with red and green colours, respectively. The * in the figures shows the statically significant results between populations. IR: infection rate; DIR: dissemination rate; TR: transmission rate; TE: transmission efficiency.

Table 2. Comparison of disseminated infection rates between mosquito population, dpe and viral strains using a generalized linear model with a binomial family distribution (logistic regression).

	DIR
	d.f.	χ^2	p value
Dpe	2	28.551	6.31E-07***
Strain	1	23.6072	1.18E-06***
Population	1	0.0524	0.8189
Dpe*Strain	2	2.482	0.2891
Dpe*Population	2	1.7889	0.4088
Strain*Population	1	1.4643	0.2262
Dpe*Strain*Population	2	4.2258	0.1209

***p-value <0.0001; Dpe: days post-exposure; d.f.: degrees of freedom.

Figure 2. ZIKV loads in saliva (Plaque forming units [PFU/mL]) of infected female mosquitoes from two field-collected Ae. albopictus mosquito populations (El Prat del Llobregat and Rubí) exposed to Dakar and Martinique ZIKV strains. *Dpe: days post-exposure to the virus.

Figure 3. Infection and dissemination rates and transmission efficiency of the progeny of infected females from of one field-collected Ae. albopictus population (Rubí) for Dakar and Martinique ZIKV strains. IR: infection rate; DIR: dissemination rate; TE: transmission efficiency.

Table 3. Number of eggs obtained from ZIKV inoculated females during the first and second gonotrophic cycle and filial infection rates (including males and females).

Specie	Generation	Strains	Viral doses	FEF females	Egg E1	Filial infection rate	Egg E2	Filial infection rate
Ae. albopictus	F0-F1	Dak84	7.5 log10 TCID50/ml	34	559	1: 19.9	322	<1: 322 (0%)
Ae. albopictus	F0-F1	Martinique	7.5 log10 TCID50/ml	19	272	1: 38.8	94	1: 23.5
Ae. albopictus	F1	Martinique	8.2 log10 TCID50/ml	12	140	1: 28	133	N.D.

Note: FEF: full-engorged inoculated females; E1: first gonotrophic cycle; E2: second gonotrophic cycle; N.D.: No data.