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Volume 32, Number 9—September 2026
Dispatch
Case Report and Retrospective Review of Acanthamoeba Encephalitis and Chronic Lymphocytic Leukemia, United States
Michele Persico
, Julia C. Haston, Erin Imada, Jennifer Kasten, Cederic Pimentel, and Jeffrey M. Collins
, Julia C. Haston, Erin Imada, Jennifer Kasten, Cederic Pimentel, and Jeffrey M. Collins
Table
Clinical and demographic characteristics of Acanthamoeba cases in the United States during 1956–2023*
| Characteristic | Total no. patients | No. (%) patients |
||||
|---|---|---|---|---|---|---|
| Any cancer, n = 56 | No cancer, n = 137 | CLL, n = 17 | Other hematologic malignancy, n = 31 | Nonhematologic malignancy, n = 12 | ||
| Age group, y | ||||||
| 0–17 | 11 | 2 (3.6) | 9 (6.6) | 0 | 2 (6.5) | 0 |
| 18–34 | 36 | 5 (8.9) | 31 (22.6) | 0 | 5 (16.1) | 1 (8.3) |
| 35–64 | 105 | 25 (44.6) | 80 (58.4) | 6 (35.3) | 16 (51.6) | 4 (33.3) |
| >65 | 36 | 23 (41.1) | 13 (9.5) | 11 (64.7) | 7 (22.6) | 7 (58.3) |
| Unknown |
5 |
1 (1.8) |
4 (2.9) |
0 |
1 (3.2) |
0 |
| Sex | ||||||
| M | 132 | 37 (66.1) | 95 (69.3) | 14 (82.4) | 17 (54.8) | 9 (75) |
| F | 57 | 17 (30.4) | 40 (29.2) | 2 (11.8) | 13 (41.9) | 3 (25) |
| Unknown |
4 |
2 (3.6) |
2 (1.5) |
1 (5.9) |
1 (3.2) |
0 |
| Ethnicity/race | ||||||
| Hispanic | 21 | 5 (8.9) | 16 (11.7) | 0 | 4 (12.9) | 1 (8.3) |
| NH White | 24 | 13 (23.2) | 11 (8) | 9 (53) | 3 (9.7) | 2 (16.7) |
| NH Asian | 3 | 0 | 3 (2.2) | 0 | 0 | 0 |
| NH Black | 6 | 0 | 6 (4.4) | 0 | 0 | 0 |
| NH American Indian or Alaskan Native | 1 | 0 | 1 (0.7) | 0 | 0 | 0 |
| Other | 51 | 8 (14.3) | 43 (31.4) | 2 (11.8) | 5 (16.1) | 2 (16.7) |
| Unknown |
87 |
30 (53.6) |
57 (41.6) |
6 (35.3) |
19 (61.3) |
7 (58.3) |
| Survived | ||||||
| Y | 32 | 11 (19.6) | 21 (15.3) | 8 (47.1) | 2 (6.5) | 1 (8.3) |
| N | 133 | 34 (60.7) | 99 (72.3) | 3 (17.6) | 25 (80.6) | 10 (83.3) |
| Unknown |
28 |
11 (19.6) |
17 (12.4) |
6 (35.3) |
4 (12.9) |
1 (8.3) |
| Disease manifestation | ||||||
| GAE only | 78 | 20 (35.7) | 58 (42.3) | 3 (17.6) | 12 (38.7) | 7 (58.3) |
| Cutaneous only | 19 | 8 (14.3) | 11 (8) | 5 (29.4) | 3 (9.7) | 0 |
| Rhinosinusitis only | 8 | 1 (1.8) | 7 (5.1) | 1 (5.9) | 0 | 0 |
| Disseminated with GAE | 58 | 19 (33.9) | 39 (28.5) | 5 (29.4) | 12 (38.7) | 4 (33.3) |
| Disseminated without GAE | 30 | 8 (14.3) | 22 (16.1) | 3 (17.6) | 4 (12.9) | 1 (8.3) |
*The total number of patients with cancer was 56. The sum of patients represented in the CLL, other hematologic malignancy, and nonhematologic malignancy categories is 60; several patients had >1 malignancy and are represented in multiple categories. CLL, chronic lymphocytic leukemia, GAE, granulomatous amebic encephalitis; NH, non-Hispanic.
Page created: July 30, 2026
Page updated: August 18, 2026
Page reviewed: August 18, 2026
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