TABLE 3. Characteristics of specimens from humans and animals received at CDC for laboratory confirmation of Dracunculus medinensis — January 2022–June 2023.
| Characteristic | Surveillance period |
|||
|---|---|---|---|---|
| 2023 |
2022 |
|||
| Jan–Jun | Jan–Jun | Jul–Dec | Jan–Dec | |
|
Human specimens
| ||||
|
Country of origin, no. of positive specimens (patients)*
| ||||
| Central African Republic |
—† |
— |
1 (1) |
1 (1) |
| Chad |
1 (1) |
3 (3) |
5 (5) |
8 (8) |
| Ethiopia |
— |
— |
1 (1) |
1 (1) |
| South Sudan |
— |
— |
9 (6) |
9 (6) |
|
Total no. (%) of positive specimens
|
1 (7)
|
3 (15)
|
16 (48)
|
19§
(36) |
|
Negative specimens, no. (%) of laboratory identifications
| ||||
| Free-living organism¶ |
1 (7) |
1 (6) |
3 (18) |
4 (12) |
|
Onchocerca sp. |
2 (14) |
6 (35) |
5 (29) |
11 (32) |
| Other parasitic helminth** |
— |
— |
1 (6) |
1(3) |
| Other parasitic nematode†† |
4 (29) |
1 (6) |
— |
1 (3) |
| Plant material |
— |
2 (12) |
1 (6) |
3 (9) |
| Sparganum |
3 (21) |
3 (18) |
1 (6) |
4 (12) |
| Tissue (animal origin) |
1 (7) |
4 (24) |
5 (29) |
9 (26) |
| Unknown origin |
3 (21) |
— |
1 (6) |
1 (3) |
|
Total no. (%) of negative specimens*
|
14 (93)
|
17 (85)
|
17 (52)
|
34 (64)
|
|
Total no. of human specimens
|
15
|
20
|
33
|
53
|
|
Animal specimens
| ||||
|
Positive specimens, country and species of origin, no. of specimens (no. of animals)*
| ||||
|
Angola
| ||||
| Dog |
32 (32) |
6 (6) |
1 (1) |
7 (7) |
|
Cameroon
| ||||
| Dog |
67 (65) |
— |
46 (28) |
46 (28) |
|
Chad
| ||||
| Cat |
— |
2 (2) |
2 (2) |
4 (4) |
| Dog |
8 (7) |
— |
1 (1) |
1 (1) |
| Other animals (mustelid) |
— |
— |
1 (1) |
1 (1) |
|
Ethiopia
| ||||
| Baboon |
— |
— |
2 (2) |
2 (2) |
| Dog |
— |
— |
1 (1) |
1 (1) |
| Other animal (wildcat) |
1 (1) |
— |
— |
— |
|
Mali
| ||||
| Cat |
— |
— |
2 (2) |
2 (2) |
| Dog |
6 (6) |
2 (2) |
43 (40) |
45 (42) |
|
South Sudan
| ||||
| Dog |
— |
— |
1 (1) |
1 (1) |
|
No. (%) of positive specimens*
|
114 (87)
|
10 (83)
|
100 (88)
|
110 (88)
|
|
Total no. (%) of negative specimens*
|
17 (13)
§§
|
2 (17)
|
13 (12)
|
15 (12)
¶¶
|
| Total no. of animal specimens | 131 | 12 | 113 | 125 |
* Positive specimens were confirmed as D. medinensis; negative specimens were ruled out as D. medinensis.
† Dashes indicate no specimens received.
§ CDC received 19 specimens in 2022: one was from 2021 (Chad), and 18 were from 2022. The specimens from 2022 were from 13 human cases among which 10 had one specimen each, two had two specimens each, and one had three specimens.
¶ Free-living organisms primarily included adult Mermithidae and other worms identified as belonging to nonparasitic taxa.
** Other parasitic helminths submitted in association with human cases belonging to the cestode class (flatworms).
†† Other parasitic nematodes submitted in association with human cases belonging to the filarioidea or ascarididae families.
§§ In 2023, the 17 D. medinensis–negative specimens were identified as follows: 10 were other parasitic nematodes from which five were filaroidea, three were Setaria sp., and one was Hastopiculum sp., and one strongyloidea; one other parasitic helminth was a cestode; two were free-living organisms (mermithids); one was animal tissue, likely from fish; and three samples were of unknown origin.
¶¶ The 15 negative specimens from animals from 2022 were identified as follows: eight were other parasitic nematodes from which five were filaroidea, one was Hastopiculum sp., one was Protospirura sp., and one was nematode; one was another parasitic helminth (a cestode); two were spargana; two were free-living organisms (mermithids); and two were animal tissues (one tendon-like tissue and one case of possibly congealed mucus).