Background
Methods
Study design
Retrospective-longitudinal study
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antimalarial antibody titre (IFAT-Biomérieux) ≥1/160, PLUS:
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massive splenomegaly (ultrasound longitudinal diameter, corresponding to spleen length, ≥16 cm) (normal value in healthy adults 8–11 cm) [9];
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IgM level ≥2 SD above the local mean (or ≥2.5 g/L according to the local laboratory);
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no other identifiable cause of splenomegaly or of raised IgM, such as schistosomiasis, cirrhosis, haematological conditions, and others as described previously [8].
Data entry and data elaboration
Definition of follow-up criteria
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Cured: absence of splenomegaly and normal IgM value;
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Improved: ≥1 cm decrease of the spleen diameter, or unchanged spleen diameter and ≥1 g/dL decrease of IgM level;
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Unchanged: <1 cm or no variation of the spleen diameter and <1 g/dL or no variation of IgM level;
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Progressed: ≥1 cm increase of the spleen diameter, or unchanged spleen diameter and ≥1 g/dL increase of IgM level.
Laboratory methods for malaria detection
Treatment and prophylaxis
Statistical analysis
Ethical issues
Results
The study population
Characteristic | All (n = 44) | Expatriates (n = 36) | Immigrants (n = 8) | p value |
---|---|---|---|---|
Age years; median (IQ range) | 56.1 (15.8) | 58.6 (10.0) | 27.4 (14.2) | 0.0001 |
Gender (F/M) | 15/29 | 10/26 | 5/3 | 0.099 |
Exposure, years; median (IQ range) | 20.0 (13.0) | 20.0 (12.0) | 27.5 (12.0) | 0.2278 |
Presence of symptoms; ratio Y/Na
| 42/1 | 34/1 | 8/0 | 1.000 |
Fever; ratio Y/N* | 24/19 | 19/16 | 5/3 | 1.000 |
Asthenia; ratio Y/N* | 19/24 | 18/17 | 1/7 | 0.059 |
Left upper q. pain; ratio Y/Na
| 9/34 | 6/29 | 3/5 | 0.332 |
Intestinal discomfort ratio Y/Na
| 12/31 | 11/24 | 1/7 | 0.407 |
Spleen diameter in cm; median (IQ range) | 18.0 (3.3) | 18.0 (3.3) | 17.6 (3.5) | 0.5643 |
Hepatomegaly; ratio Y/Na
| 23/20 | 21/14 | 2/6 | 0.118 |
Hb, mg/dL normal 12–16; median (IQ range) | 10.0 (3.0) | 9.6 (2.2) | 11.6 (4.0) | 0.1695 |
RBC × 106/µL, n 4.2–5.4; median (IQ range) | 3.4 (1.0) | 3.3 (0.9) | 4.0 (1.1) | 0.0239 |
Plt × 103/µL, n 130–400; median (IQ range) | 138.0 (81.0) | 128.0 (76.0) | 178.5 (100.0) | 0.0702 |
ESR mm/h, n < 25; median (IQ range) | 57.5 (43.5) | 59.0 (38.0) | 51.0 (86.0) | 0.7352 |
IgM, g/L, n < 2.5; median (IQ range) | 6.4 (3.9) | 6.8 (3.8) | 5.0 (12.6) | 0.9738 |
Plasmodium in blood; ratio Y/Nb
| 22/16 | 17/15 | 5/1 | 0.370 |
Improved at T1; ratio Y/N | 20/2 | 16/2 | 4/0 | 1.000 |
Parasite detection
Parasitaemia (N/µL) | All | Expatriates | Immigrants |
---|---|---|---|
Negative | 16 (42 %) | 15 (47 %) | 1 (17 %) |
QBCa
| 9 (24 %) | 7 (22 %) | 2 (33 %) |
1–500/µL | 9 (24 %) | 6 (19 %) | 3 (50 %) |
501–2000/µL | 3 (8 %) | 3 (9 %) | 0 (0 %) |
>2000/µL | 1 (2 %) | 1 (3 %) | 0 (0 %) |
Total | 38 | 32 | 6 |
Short-term outcome
Outcome | Expatriates | Immigrants | Total |
---|---|---|---|
Cured or improved | 16 | 4 | 20 |
Unchanged | 2 | 0 | 2 |
Total | 18 | 4 | 22 |
Long-term outcome
Outcome | Prophylaxis | Intermittent treatment |
Total
|
---|---|---|---|
Cured or improved | 8 | 10 | 18 |
Unchanged or progressed | 1 | 3 | 4 |
Total | 9 | 13 | 22 |