New insights on the Taenia solium tapeworm using molecular tools: age-based human definitive host prevalence and deliberation on parasite life span

Figures & data

Figure 1. A: Map of Sichuan Province indicating the location of Shuiluo Township, Muli County, Liangshan Prefecture, and the provincial capital (Chengdu); B: Map of China with the location of Sichuan Province and the country’s capital (Beijing).

Figure 2. Diagram showing study process and the number of participants from the village of Guni, Liangshan Prefecture, Sichuan Province, China.

Table 1. Species-specific distribution of tapeworms in children (n = 113) and adults (n = 276) in the village of Guni, Sichuan Province, China (2017)

Infecting species	Number of cases (%) in children	Number of cases (%) in adults
T. solium	7 (6.19)	4 (1.45)
T. Saginata asiatica	11 (9.73)	132 (47.83)b
T. saginata	1 (0.88)	16 (5.80)c
T. solium + T. saginata asiatica	1 (0.88)	2 (0.72)
T. solium + T. saginata	2 (1.77)	0 (0.00)
T. saginata asiatica + T. saginata	1 (0.88)	14 (5.07)
T. solium + T. saginata asiatica + T. saginata	0 (0.00)	1 (0.36)
Species not identified	1 (0.88)a	1 (0.36)d

a: stool sample not provided and the post-treatment expelled tapeworms not collected

b: 16 cases identified by coproPCR and sequencing

c: 2 cases identified by coproPCR and sequencing

d: positive for Taenia eggs, but no stool sample for coproPCR (subject not treated)

Figure 3. Age-based prevalence of taeniasis in the village of Guni, Sichuan Province, China. The black line indicates all three Taenia species. The red line refers to T. solium, the purple line refers to T. saginata asiatica, and the blue line refers to T. saginata (n = number of positive cases).

Table 2. Demographic information and infecting species for Taenia egg-positive children attending Shuiluo Primary School, Sichuan Province in 2016 without tapeworm expulsion (n = 10) and with tapeworm expulsion (n = 13) following treatment 8 months after diagnosis

Sex	Age (years)	History of SE	Duration of SE	Frequency of SE	Infecting species	Number of worms expelled
male	6	positive	unclear	occasionally	T. saginata asiatica*	0
female	7	negative	ND	ND	ND	0
male	11	positive	3 years	occasionally	T. solium*	0
female	11	positive	3 years	occasionally	T. solium**	0
male	13	positive	1 year	occasionally	T. solium*	0
female	13	positive	1 year	occasionally	ND	0
female	14	positive	2 years	occasionally	T. solium*	0
male	14	positive	unclear	occasionally	T. solium*	0
male	15	positive	3 years	occasionally	T. solium*	0
male	15	negative	ND	ND	ND	0
male	8	positive	1 year	occasionally	T. solium	1
male	8	positive	1 year	occasionally	T. solium	1
female	8	positive	unclear	occasionally	T. solium	1
male	9	positive	1 year	occasionally	T. solium + T. saginata	2
male	9	positive	unclear	occasionally	T. solium	1
male	11	positive	> 2 years	frequently	T. solium	1
female	11	positive	1 year	occasionally	T. solium	1
male	11	positive	2 years	frequently	T. solium + T. saginata asiatica	2
male	11	positive	> 2 years	frequently	T. solium	11
female	12	positive	2 years	frequently	T. saginata	1
female	12	positive	unclear	occasionally	T. solium	1
female	13	positive	1 year	frequently	T. saginata	1
male	15	positive	3 years	frequently	T. solium	6

*: identified by coproPCR and sequencing

**: identified by coproPCR only

SE: segment expulsion

ND: not determined