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Tras una década de tratamiento anual monodosis con ivermectina en Camerún y Uganda, continúa la transmisión de oncocercosis
Author(s) -
Katabarwa Moses,
Eyamba Albert,
Habomugisha Peace,
Lakwo Tom,
Ekobo Same,
Kamgno Joseph,
Kuete Thomas,
Ndyomugyenyi Richard,
Onapa Ambrose,
Salifou Mkpouwoueiko,
Ntep Marcelline,
Richards Frank O.
Publication year - 2008
Publication title -
tropical medicine and international health
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.056
H-Index - 114
eISSN - 1365-3156
pISSN - 1360-2276
DOI - 10.1111/j.1365-3156.2008.02126.x
Subject(s) - microfilaria , onchocerciasis , ivermectin , medicine , transmission (telecommunications) , tropical medicine , population , demography , veterinary medicine , environmental health , filariasis , helminths , immunology , pathology , sociology , electrical engineering , engineering
Summary Objective To evaluate the effectiveness of 10 years’ annual single dose ivermectin treatment on onchocerciasis transmission in hyperendemic areas of Cameroon and Uganda. Methods Baseline nodule and microfilaria (‘skin snip’) prevalence data were available from 10 hyperendemic sentinel communities in Cameroon (from 1996) and hyperendemic 20 sentinel communities in Uganda (from 1993). We returned to these villages in 2005, 10 months after the last annual ivermectin distribution, to repeat the cross‐sectional surveys. Each sentinel community reported a mean interval treatment coverage of eligible persons of >88% (range 37–100%). Data were analyzed for more than 6200 person examinations. In Cameroon, 719 people ≥10 years were examined at the baseline survey in 1996 and 838 at the follow‐up survey in 2005. In Uganda, 1590 people ≥10 years were examined at the baseline survey in 1993 and 2122 people at the follow‐up survey in 2005. We also examined children under 10 in Cameroon (1996, n = 185; 2005, n = 448) and Uganda (1993, n = 177; 2005, n = 130). In Uganda, the vitality of worms was judged using standard histological criteria in 80 nodules excised in 2005. Results The prevalence of microfilaria carriers among older children and adults (≥10 years) in Cameroon sentinel communities dropped from 70.1% to 7.04% ( P < 0.0001) over the 10‐year treatment period; that of nodule carriers from 58% to 9.55% ( P < 0.0001). Similarly, in Uganda, the prevalence of microfilaria carriers fell from 71.9% to 7.49% ( P < 0.0001) over the 13‐year treatment period, and that of nodule carriers from 53.21% to 9.66% ( P < 0.0001). The number of microfilaria carriers among children <10 years in Cameroon decreased from 29.73% to 3.8% ( P < 0.0001), and in Uganda from 33.89% to 3.1% ( P < 0.0001). In 2005, worms excised from nodules in Uganda, 81.4% of males remained alive, and 64% of females, with 24% of them inseminated. Conclusion A decade or more of annual single dose ivermectin treatment in hyperendemic areas has reduced onchocerciasis to ‘hypoendemicity’, but onchocerciasis transmission persists. For now, annual treatment with ivermectin should be continued in formerly mesoendemic and hyperendemic zones.