Skip to main content

Table 2 Acute-phase clinical and laboratory features of patients followed > 720 days post-symptom onset by IgM status

From: Long-term persistence of serum IgM antibodies against chikungunya virus in patients with chronic arthralgia

Characteristics

Anti-CHIKV IgM persistence > 720 days

(n = 7)

Anti-CHIKV IgM persistence ≤ 720 days

(n = 14)

Without sample collection

 > 720 days

(n = 24)

Total

(N = 45)

P Valuea

n (%) or median (interquartile range)

 

Demographic

Sex (female)

5 (71)

9 (64)

19 (79)

33 (73)

0.59

Age

52 (37–56)

43 (32–47)

44 (31–67)

44 (35–56)

0.41

Acute chikungunya clinical manifestations

Fever

7 (100)

13 (93)

24 (100)

44 (97)

0.46

Arthralgia

7 (100)

14 (100)

24 (100)

45 (100)

-

Myalgia

7 (100)

14 (100)

24 (100)

45 (100)

-

Joint edema b

6 (85)

9 (64)

16 (66)

31 (68)

0.74

Rash

2 (28)

6 (42)

10 (43) c

18 (41) d

0.83

Pruritus

2 (28)

5 (33)

10 (41)

17 (37)

0.91

Abdominal pain

5 (71)

9 (64)

7 (29)

21 (46)

0.03

Vomit

1 (14)

2 (14)

8 (33)

11 (24)

0.45

Prior medical conditions

Pre-existing joint pain

3 (42)

6 (42)

7 (35)

16 (35)

0.62

Hypertension

2 (28)

4 (28)

8 (33)

14 (31)

1.00

Diabetes

1 (14)

2 (14)

1 (4)

4 (8)

0.46

Laboratory results, 0–7 DPSO

Anti-CHIKV IgM positive e,,f

1 (14)

1 (7)

4 (16)

6 (13)

0.84

Sample OD/calibrator ratio

0.27 (0.16–0.44)

0.20 (0.15–0.43)

0.21 (0.15–0.55)

0.23 (0.16–0.48)

0.90

Anti-CHIKV IgG positive e,g

0 (0)

0 (0)

1 (4)

1 (2)

1.00

Sample OD/calibrator ratio

0.18 (0.18–0.30)

0.20 (0.16–0.31)

0.19 (0.14–0.28)

0.19 (0.15–0.30)

0.85

RT-qPCR CHIKV positive

5 (71)

14 (100)

24 (100)

43 (95)

0.02

      Cycle threshold

20.68 (20.4–22.82)

22.49 (20.05–27.66)

24.97 (20.43–33.23)

22.96 (20.06–30.51)

0.08

Laboratory results, 10–30 DPSO

n = 7

n = 11

n = 22

n = 40

 

Anti-CHIKV IgM positive c,d

7 (100)

11 (100)

22 (100)

40 (100)

-

Sample OD/calibrator ratio

11.63 (10.12–16.43)

13.40 (9.71–13.88)

10.19 (9.44–15.18)

10.71 (9.61–14.52)

0.68

Anti-CHIKV IgG positive e,g

7 (100)

11 (100)

22 (100)

40 (100)

-

Sample OD/calibrator ratio

2.24 (2.11–3.09)

2.34 (1.95–2.49)

2.35 (1.98–2.64)

2.33 (1.98–2.64)

0.93

RT-qPCR CHIKV positive

0 (0)

2 (18)

0 (0)

2 (5)

0.69

       Cycle threshold

–

36.75 (35.6–37.9)

–

36.75 (35.6–37.9)

–

  1. a P-values were calculated using the Kruskall-Wallis test for quantitative variables and Fisher’s exact test for categorical variables
  2. b This variable refers to edema in at least one of the following joints: fingers, toes, elbows, wrists, knees and ankles
  3. c Data available for 23 patients
  4. d Data available for 44 patients
  5. e Sample/calibrator ratio is calculated from the ratio of the optical density obtained with the test sample divided by the calculated calibrator value
  6. f Results based on sample/calibrator ratio for IgM ELISA are interpreted as follows: < 0.9 = Negative; > 1.1 = Positive; ≥ 0.9 and ≤ 1.1 = Indeterminate
  7. g Results based on sample/calibrator ratio for IgG ELISA are interpreted as follows: < 0.8 = Negative; ≥ 1.1 = Positive; ≥ 0.8 and < 1.1 = Indeterminate
Back to article page

Virology Journal

ISSN: 1743-422X