Table 2.
Results of laboratory screening for potential etiologies among Congolese refugees diagnosed with splenomegaly before or after U.S. resettlement compared with matched controls
| Clinical characteristic* | All case patients (n = 130) | Splenomegaly on arrival (n = 95) | Persistent or chronic splenomegaly† (n = 45) | Splenomegaly not detected on arrival (n = 35) | Controls (n = 102) | |||||
|---|---|---|---|---|---|---|---|---|---|---|
| n | % | n | % | n | % | n | % | n | % | |
| Elevated IgM† | 8/25 | 32.0 | 8/25 | 32.0 | 5/16 | 31.3 | – | – | – | – |
| Malaria smear (+), polymerase chain reaction (+), or RDT (+) | 65/112 | 58.0 | 42/79 | 53.2 | 22/35 | 62.9 | 23/32 | 71.9 | 3/10 | 30.0 |
| Elevated Schistosoma IgG | 17/30 | 56.7 | 16/28 | 57.1 | 11/17 | 64.7 | 1/2 | 50.0 | 4/12 | 33.3 |
| Eosinophilia | 9/16 | 56.3 | 9/15 | 60.0 | 6/10 | 60.0 | 0/1 | 0 | 0/3 | 0 |
| No eosinophilia | 7/16 | 43.8 | 6/15 | 40.0 | 4/10 | 40.0 | 1/1 | 100.0 | 3/3 | 100.0 |
| Received primaquine§ | 48/129 | 37.2 | 45/94 | 47.9 | 28/45 | 62.2 | 3/35 | 8.6 | – | – |
| Sickle cell anemia | 0/53 | 0 | 0/33 | 0 | 0/19 | 0 | 0/20 | 0 | – | – |
| Hepatitis A (IgG positive) | 17/30 | 56.7 | 16/27 | 59.3 | 8/15 | 53.3 | 1/3 | 33.3 | 15/29 | 51.7 |
| Hepatitis B (HBsAg positive) | 1/115 | 0.9 | 1/84 | 1.2 | 1/40 | 2.5 | 0/31 | 0 | 2/98 | 2.0 |
| Hepatitis C (IgG positive) | 14/102 | 13.7 | 11/75 | 14.7 | 5/35 | 14.3 | 3/27 | 11.1 | 4/31 | 12.9 |
RDT = rapid diagnostic test; HBsAg = hepatitis B surface antigen.
Two patients with splenomegaly were screened by serology for brucellosis, and neither was infected. No patients were screened for Epstein–Barr virus infection before departure or during the follow-up period. One patient tested positive for Schistosoma mansoni ova by stool ova and parasite examination before departure and had splenomegaly on arrival that resolved within 6 months.
Persistent (splenomegaly present ≥ 6 months after arrival) or long-term splenomegaly (present ≥ 18 months after arrival) case patients are among those who had splenomegaly on arrival; that is, these are not mutually exclusive categories.
Cutoff value for elevated total IgM: > 304 mg/dL. In the absence of cutoff values used for all domestic laboratories that screened these patients, the highest reported cutoff value was used.
Patient record of receipt of primaquine at any point after U.S. arrival, regardless of the duration of the course. AST = aspartate aminotransferase.