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
| 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 | – | – | |
† 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]