TABLE 3. Characteristics of specimens from humans and animals received at CDC for laboratory diagnosis of Dracunculus medinensis — January 2021–June 2022.
| Characteristic | 2021 |
2022 |
||
|---|---|---|---|---|
| Jan–Dec 2021 | Jan–Jun 2021 | Jul–Dec 2021 | Jan–Jun 2022 | |
|
Human specimens
| ||||
|
Total no. received
|
45
|
13
|
32
|
20
|
| No. (%) positive* |
14† (31) |
5 (38) |
9† (28) |
3† (15) |
|
Country of origin, no. of positive specimens (no. of patients)
| ||||
| Chad |
7† (7) |
4 (4) |
3 (3) |
3 (3) |
| Ethiopia |
1 (1) |
1 (1) |
—§ |
— |
| Mali |
2 (2) |
— |
2 (2) |
— |
| South Sudan |
4 (4) |
— |
4 (4) |
— |
| No (%) negative* |
31 (68) |
8 (62) |
23 (72) |
17 (85) |
|
Negative specimens, no. (%) of other laboratory identifications
| ||||
|
Onchocerca sp. |
— |
— |
— |
6 (35) |
| Free-living nematode¶ |
8 (26) |
2 (25) |
6 (26) |
1 (6) |
| Other parasitic nematode** |
2 (6) |
— |
2 (9) |
1 (6) |
| Sparganum |
5 (16) |
3 (38) |
2 (9) |
3 (18) |
| Cestode (non-sparganum) |
1 (3) |
— |
1 (4) |
— |
| Annelid |
2 (6) |
— |
2 (9) |
— |
| Animal-origin tissue |
9 (29) |
2 (25) |
7 (30) |
4 (24) |
| Plant material |
2 (6) |
— |
2 (4) |
2 (12) |
| Unknown origin |
2 (6) |
1 (13) |
1 (4) |
— |
|
Animal specimens
| ||||
|
Total no. received
|
73
|
36
|
37
|
12
|
| No. (%) positive* |
38 (52) |
6 (17) |
32 (86) |
10 (83) |
|
Positive specimens, country/species of origin, no. of specimens (no. of animals)
| ||||
|
Angola
| ||||
| Dog |
— |
— |
— |
6 (6) |
|
Cameroon
| ||||
| Dog |
10 (10) |
— |
10 |
— |
|
Central African Republic
| ||||
| Dog |
1 (1) |
1 |
— |
— |
|
Chad
| ||||
| Cat |
2 (2) |
— |
2 |
2 (2) |
| Dog |
4 (4) |
2 |
2 |
— |
| Other animals (wildcats) |
2 (2) |
1 |
1 |
— |
|
Ethiopia
| ||||
| Cat |
1 (1) |
— |
1 |
— |
| Dog |
2 (2) |
— |
2 |
— |
|
Mali
| ||||
| Cat |
1 (1) |
— |
1 |
— |
| Dog |
15 (15) |
2 |
13 |
2 (2) |
| No. (%) negative specimens*,†† | 35 (48) ** | 30 (83) | 5 (14) | 2 (17)§§ |
* Positive specimens were confirmed as D. medinensis; negative specimens were ruled out as D. medinensis.
† CDC received 15 specimens from human cases in 2022 and 14 in 2021. The remaining specimen received in February 2022 was from a human case in Chad.
§ Dashes indicate no specimens received.
¶ Free-living nematodes primarily included adult Mermithidae and other nematodes identified as belonging to nonparasitic taxa. Other parasitic nematodes included non-Onchocerca nematodes identified as belonging to parasitic taxa.
** Other parasitic nematodes submitted in association with human cases during January–December 2021 included one ascarid, a Eustrongylides-like nematode; in 2022, the one other parasitic nematode was ascarid.
†† The 35 negative specimens from animals were identified as follows: 24 Filaroidea from which three were Setaria sp., 12 were in the subfamily Dirofilariinae (e.g., Dirofilaria, Skjrabinodera), and nine were only identified at the superfamily level (Filarioidea); among the 11 remaining negative specimens five were free-living nematodes, two Mastophorus or Protospirura-like nematodes, one Eustrongylides sp., two were not identified past superfamily Spiruroidea, and one was a horsehair worm (Nematomorpha).
§§ One specimen was identified only at the superfamily level (Filarioidea), and the other was a nematode in the family Diplotriaenidae.