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Table 2 Prevalence and intensity of Onchocerca volvulus microfilariae (mf) in the baseline and pre-ivermectin MDA period (1981– 2000), in sentinel and extra-sentinel communities of the Amazonian focus of southern Venezuela

From: Evidence of suppression of onchocerciasis transmission in the Venezuelan Amazonian focus

Geographical sub-area

Community (altitude, masl)

Positive/examined

Prevalence (%) of skin mf (95 % CI)

AM (mf/mg)

WM§ (mf/mg)

CMFL (mf/ss)

MFC (%)

MFAC¦ (%)

Sentinel communities

Guaharibos

1 Hasupiwei (200)

39/47b

83.0 (69.2, 92.4)

50.4

12.7

21.3

36/44c

81.8 (67.3, 91.8)

48.7

20.3

43.7

39+,d

46.2

43.6

Jénita –Putaco

2 Awei (162)

15/24b

62.5 (40.6, 81.2)

61.3

11.4

52.4

15/18d

83.3 (58.6, 96.4)

60.6

10.8

14.4

17.6

5.9

3 Pashopëka (240)

29/38b

76.3 (59.8, 88.6)

33.8

9.6

19.7

43/51d

84.3 (71.4, 93.0)

49.9

14.1

17.4

39.2

0

Orinoquito

4 Koyowë (250)

54/64a

84.4 (73.1, 92.2)

146.3

25.7

72.6

59/72c

81.9 (71.1, 90.0)

80.2

18.8

11.0

54+,d

35.2

13.0

5 Waharafitha (260)

36/36e

100 (90.3, 100)

62.1

23.0

57.7

50.0

75.0

6 Matoa (360)

51/53e

96.2 (87.0, 99.5)

84.4

36.2

50.8

17.0

24.4

Parima B

7 Kanoshewë* (819)

34/48d

70.8 (55.9, 83.0)

12.5

3.6

4.6

54+,d

5.6

0

8 Niayopë* (950)

120/179a

67.0 (59.6, 73.9)

44.5

7.6

43.2

10.0

22+,d

4.6

0

Extra-sentinel communities

Peñascal

9 Yaurawë (198)

19/20d

95.0 (75.1, 99.1)

133.3

38.7

68.6

29.3

37.9

Parima A

10 Masiriki (990)

19/21d

90.5 (69.6, 98.8)

122.8

26.6

31.1

11 Toumawei (1037)

19/19d

100 (82.4, 100)

231.2

102.6

104.7

Parima B

12 Arokofita* (871)

22/31d

71.0 (52.0, 85.8)

9.3

2.9

7.6

13 Okiamo* (927)

13/36d

36.1

8.8

0.98

1.1

8+,d

25.0

0

Parima C

14 Warapawë (1007)

23/24d

95.8 (78.9, 99.9)

79.7

20.1

15.6

Shamatari

15 Kakarama** (669)

39/47b

83.0 (69.2, 92.4)

50.4

12.7

33.8

16 Pokoshiprare** (721)

19/33b

57.6 (39.2, 74.5)

39.6

4.7

30.0

  1. AM arithmetic mean no. of mf/mg; § WM geometric mean (of Williams) no. of mf/mg; CMFL community microfilarial load, the geometric mean no. of mf per skin snip (ss) in those individuals aged ≥20 years; MFC prevalence of mf in cornea; ¦ MFAC prevalence of mf in the anterior chamber of the eye; a1981, b1995, c1997, d1998, e2000; +examined for ocular lesions only, *the community of Niayopë, formerly called Niyayowë and studied in 1981, included Kanoshewë, Arokofita and Okiamo; therefore, although these communities did not exist as separate entities at the time of the baseline study in 1981, their infection levels are assumed to be the same as those of Niyayowë/Niayopë; ** Kakarama and Pokoshiprare originated from Yoreshiana A and B, studied by [26]