Table 1 Lassa fever case characteristics and time to presentation, Nigeria 2019, (n = 389)

Case definition number of cases

Laboratory Confirmed

389

208 (53.4)

6

4–10

1–21

Sex

Female

181 (46.5)

101 (55.8)

6

3–10

1–21

Male

207 (53.2)

107 (51.7)

6

4–10

1–21

Unknown

1 (0.3)

0

7

n/a

n/a

Age group (years)

0–4

21 (5.4)

11 (52.4)

6

4–13

1–16

5–12

35 (9.0)

20 (57.1)

6

4–9

1–21

13–17

31 (8.0)

22 (71.0)

5

2–8

1–21

18–25

56 (14.4)

33 (58.9)

6

3–10

1–21

26–59

214 (55.0)

107 (50.0)

6

4–10

1–21

60+

31 (8.0)

14 (45.2)

7

3–10

1–14

Unknown

1 (0.3)

1 (100)

4

n/a

n/a

 Males (n = 206)

0–4

10 (4.9)

3 (30.0)

10

5–15

3–16

5–12

17 (8.3)

11 (64.7)

5

4–8

1–20

13–17

13 (6.3)

11 (84.6)

3

3–6

2–21

18–25

27 (13.1)

16 (59.3)

6

3–10

1–16

26–59

123 (59.7)

59 (48.0)

7

5–10

1–21

60+

16 (7.8)

6 (37.5)

7

2–10

1–14

 Females (n = 181)

0–4

11 (6.1)

8 (72.7)

4

3–7

1–14

5–12

18 (9.9)

9 (50)

6

4–10

1–21

13–17

18 (9.9)

11 (61.1)

5

2–9

1–18

18–25

29 (16)

17 (58.6)

6

3–12

1–21

26–59

90 (49.7)

48 (53.3)

6

4–12

1–20

60+

15 (8.3)

8 (53.3)

6

3–10

1–14

 Mortality status outcome

Alive

324 (83.3)

175 (54.0)

6

4–10

1–21

Deceased

65 (16.7)

33 (50.8)

6

3–10

1–19

State of residence

Abia*

0

n/a

n/a

n/a

n/a

Adamawa

0

n/a

n/a

n/a

n/a

Akwa Ibom*

0

n/a

n/a

n/a

n/a

Anambra*

0

n/a

n/a

n/a

n/a

Bauchi

36 (9.3)

13 (36.1)

8

6–13

1–21

Bayelsa*

0

n/a

n/a

n/a

n/a

Benue

4 (1.0)

1 (25.0)

8

6–10

5–11

Borno*

0

n/a

n/a

n/a

n/a

Cross River

1 (0.3)

0

15

n/a

n/a

Delta

2 (0.5)

0

13.5

13–14

13–14

Ebonyi

33 (8.5)

14 (42.4)

7

4–10

1–14

Edo

171 (44.0)

94 (55.0)

6

4–10

1–21

Enugu

0

n/a

n/a

n/a

n/a

Ekiti*

0

n/a

n/a

n/a

n/a

Federal Capital Territory

1 (0.3)

0

11

n/a

n/a

Gombe

1 (0.3)

1 (100)

4

n/a

n/a

Imo

1 (0.3)

0

8

n/a

n/a

Jigawa*

0

n/a

n/a

n/a

n/a

Kaduna

3 (0.8)

2 (66.7)

5

3–20

3–20

Kano

0

n/a

n/a

n/a

n/a

Katsina*

0

n/a

n/a

n/a

n/a

Kebbi

1 (0.3)

1 (100)

3

n/a

n/a

Kogi

2 (0.5)

0

10

8–12

8–12

Kwara

1 (0.3)

1 (100)

2

n/a

n/a

Lagos*

0

n/a

n/a

n/a

n/a

Nasarawa

2 (0.5)

0

14.5

8–21

8–21

Niger*

0

n/a

n/a

n/a

n/a

Ogun*

0

n/a

n/a

n/a

n/a

Ondo

87 (22.4)

58 (66.7)

6

3–7

1–20

Osun*

0

n/a

n/a

n/a

n/a

Oyo

1 (0.3)

1 (100)

5

n/a

n/a

Plateau

27 (6.9)

13 (48.2)

7

2–13

1–20

Rivers

1 (0.3)

1 (100)

4

n/a

n/a

Sokoto*

0

n/a

n/a

n/a

n/a

Taraba

14 (3.6)

8 (57.1)

6

5–14

2–20

Yobe*

0

n/a

n/a

n/a

n/a

Zamfara*

0

n/a

n/a

n/a

n/a

Rurality category (based on state of residence and information from state guidance)

Rural

238 (61.2)

124 (52.1)

6

4–11

1–21

Semi-urban

14 (3.6)

7 (50.0)

6.5

4–9

3–12

Urban

134 (34.4)

75 (56.0)

6

4–9

1–20

Unknown

3 (0.8)

2 (66.7)

4

1–15

1–15

 Malaria Prevalence category

0–11%

4 (1.0)

1 (25.0)

8

6–10

4–12

12–21%

298 (76.6)

166 (55.7)

6

4–10

1–21

22–29%

3 (0.8)

2 (66.7)

4

2–15

2–15

30–36%

62 (15.9)

27 (43.55)

7

4–10

1–21

37–64%

22 (5.7)

12 (54.6)

7

5–11

2–20

 Education status

Primary

20 (5.1)

10 (50.0)

6.5

5–9.5

3–20

Secondary

32 (8.2)

19 (59.4)

5

3–9

1–15

Tertiary

35 (9.0)

17 (48.6)

7

3–10

1–20

Unknown

302 (77.6)

162 (53.6)

6

4–10

1–21

 Occupation group

Artisan

11 (2.8)

6 (54.6)

6

4–11

2–15

Business or Professional^a

101 (26.0)

45 (44.6)

7

4–11

1–20

Casual Labourer

1 (0.3)

0

7

n/a

n/a

Farmer

35 (9.0)

21 (60.0)

6

4–10

1–19

Health Worker

12 (3.1)

7 (58.3)

4.5

3.5–9.5

2–13

Housewife

32 (8.2)

14 (43.8)

7

5–13

1–21

Religious or Traditional^a

6 (1.5)

2 (33.3)

7

5–7

3–10

Student or Child or Apprentice

126 (32.4)

72 (57.1)

6

3–10

1–21

Transporter

5 (1.3)

1 (20.0)

9

7–10

4–15

Not working or Retired

10 (2.6)

4 (40.0)

8.5

3–12

1–14

Unknown

50 (12.9)

36 (72.0)

6

3–7

1–21

 Symptoms

Mild

123 (31.6)

78 (63.4)

6

4–8

1–21

Severe

22 (5.7)

12 (54.6)

6

3–8

1–14

Unknown

244 (62.7)

118 (48.4)

7

4–11

1–21

 First symptom

Mild

167 (42.9)

83 (49.7)

7

4–11

1–21

Severe

2 (0.5)

1 (50.0)

8

2–14

2–14

Unknown

220 (56.6)

124 (56.4)

6

4–9.5

1–21

 Exposure to confirmed case

No

87 (22.4)

43 (49.4)

7

4–9

1–20

Yes

39 (10.0)

20 (51.3)

6

4–10

1–20

Unknown

263 (67.6)

145 (55.1)

6

4–10

1–21

 Exposure to rodents

No

8 (2.0)

2 (25.0)

9

6.5–16

3–20

Yes

12 (3.1)

4 (33.3)

8

6–12

2–20

Unknown

369 (94.9)

202 (54.7)

6

4–10

1–21

 Part of a contact tracing list

No

124 (31.4)

57 (46.0)

7

4.5–11

1–21

Yes

36 (9.8)

19 (52.8)

6

3.5–10

1–20

Unknown

229 (58.8)

132 (57.6)

6

3–10

1–21

 History of travel

No

279 (71.7)

148 (53.1)

6

4–10

1–21

Yes

86 (22.1)

48 (55.8)

6

4–11

1–20

Unknown

24 (6.2)

12 (50.0)

6.5

3–13.5

2–21

 Attended a funeral

No

230 (59.1)

124 (53.9)

6

3–10

1–21

Yes

1 (0.3)

0

11

n/a

n/a

Unknown

158 (40.6)

84 (53.2)

6

5–10

1–21

 Participated in a funeral (touched body)

No

156 (40.1)

75 (48.1)

7

4–10

1–21

Yes

4 (1.0)

2 (50.0)

6

2–10

2–13

Unknown

229 (58.9)

131 (53.5)

6

4–10

1–21