The Reliability of Anterior Segment Lesions as Indicators of Onchocercal Eye Disease in Guatemala

Winthrop, Kevin; Proaño, Roberto; Oliva, Orlando; Arana, Byron; Mendoza, Carlos Abud; Domínguez, Alfredo; Amann, Josef; Punkosdy, George A.; Blanco, Carlos; Klein, Robert E.; Sauerbrey, Mauricio; Richards, Frank O.

doi:10.4269/ajtmh.2006.75.1058

Cited by 18 publications

(20 citation statements)

References 8 publications

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“…Only corneal stromal opacities where mf or mf fragments could be observed were counted as punctate keratitis. 24 These strict criteria requiring presence of visible mf in the corneal inflammation may have reduced the rates for punctate keratitis compared with other studies. Iritis and sclerosing keratitis were considered chronic lesions that would not necessarily respond to ivermectin treatment, whereas mf in the anterior chamber or cornea were considered acute lesions incident within the last 2 years.…”

Section: Study Sitesmentioning

confidence: 74%

Seventeen Years of Annual Distribution of Ivermectin Has Not Interrupted Onchocerciasis Transmission in North Region, Cameroon

Katabarwa¹,

Eyamba²,

Nwane³

et al. 2011

The American Society of Tropical Medicine and Hygiene

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We studied onchocerciasis transmission and impact on ocular morbidity in three health districts in North Region, Cameroon, where annual mass ivermectin treatment has been provided for 12–17 years. The studies, which took place from 2008 to 2010, consisted of skin snips for microfilariae (mf), palpation examinations for nodules, slit lamp examinations for mf in the eye, and Simulium vector dissections for larval infection rates. Adults had mf and nodule rates of 4.8% and 13.5%, respectively, and 5.5% had mf in the anterior chamber of the eye. Strong evidence of ongoing transmission was found in one health district, where despite 17 years of annual treatments, the annual transmission potential was 543 L3/person per year; additionally, children under 10 years of age had a 2.6% mf prevalence. Halting ivermectin treatments in North Cameroon now might risk recrudescence of transmission and ocular disease.

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Section: Study Sitesmentioning

confidence: 74%

Seventeen Years of Annual Distribution of Ivermectin Has Not Interrupted Onchocerciasis Transmission in North Region, Cameroon

Katabarwa¹,

Eyamba²,

Nwane³

et al. 2011

The American Society of Tropical Medicine and Hygiene

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“…The first three, in 1996 (baseline), 1998 and 2001, were carried out following the criteria and procedures recommended at that time by OEPA [18]. The last one in 2006 used the definition for onchocercal punctate keratitis described in the study by Winthrop et al [19]. In the 1996 baseline study only persons with a microfilariae-positive skin snip were examined [15, 20], while in the other 3 studies all persons aged 10 years or older who were present at the time of the assessment were studied.…”

Section: Methodsmentioning

confidence: 99%

Elimination of onchocerciasis from Colombia: first proof of concept of river blindness elimination in the world

et al. 2018

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BackgroundOnchocerciasis is a chronic parasitic infection originally endemic in 13 discrete regional foci distributed among six countries of Latin America (Brazil, Colombia, Ecuador, Guatemala, Mexico and Venezuela). In Colombia, this disease was discovered in 1965 in the Pacific Coast of the country. The National Onchocerciasis Elimination Program was established in 1993 with the aim of eliminating disease morbidity and infection transmission. In 2013, the World Health Organization (WHO) verified Colombia as free of onchocerciasis, becoming the first country in the world to reach such a goal. This report provides the empirical evidence of the elimination of Onchocerca volvulus transmission by Simulium exiguum (s.l.) after 12 years of 6-monthly mass drug administration of Mectizan® (ivermectin) to all the eligible residents living in this endemic area.MethodsFrom 1996 onwards, a biannual community-based mass ivermectin administration programme was implemented, complemented by health education and community participation. In-depth parasitological, serological and entomological surveys were conducted periodically between 1998 and 2007 to evaluate the impact of ivermectin treatment according to the 2001 WHO guidelines. When the interruption of parasite transmission was demonstrated, the drug distribution ceased and a three-year post-treatment surveillance (PTS) period (2008–2010) was initiated.ResultsAfter 23 rounds of treatment, parasitological and ophthalmological assessments showed absence of microfilariae in skin and anterior chamber of the eyes. Serological tests proved lack of antibodies against O. volvulus in children under 10 years-old. A total of 10,500 S. exiguum flies tested by PCR had no L3 infection (infectivity rate = 0.0095%; 95% CI: 0.0029–0.049) during 2004, indicating interruption of parasite transmission. However, biannual ivermectin treatments continued until 2007 followed by a 3-year PTS period at the end of which 13,481 flies were analyzed and no infective flies were found (infectivity rate = 0%; 95% CI: 0.0–0.014).ConclusionsThese results fulfilled the WHO criteria for onchocerciasis elimination. Consequently, in 2013 Colombia was verified as free of onchocerciasis, demonstrating that elimination of this neglected tropical disease is an achievable goal and paving the way for an elimination agenda to be followed by other endemic countries in Latin America and Africa.

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“…8 Because the population involved in this study had only been submitted to two rounds of ivermectin, it is possible that the relative lack of influence of onchocercal eye disease on eye pressure elevation could be related to the early eye disease and the small amount of internal and external eye damage from the disease in these eyes. However, it is worth noting that the prevalence of skin microfilaria in this population, before the mass ivermectin-based treatment beginning 18 months previously, was 87%.…”

Section: Discussionmentioning

confidence: 99%

Ocular Onchocerciasis in the Yanomami Communities from Brazilian Amazon: Effects on Intraocular Pressure

Herzog-Neto

Jaegger²,

Nascimento³

et al. 2014

The American Society of Tropical Medicine and Hygiene

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Abstract. To determine the influence of onchocercal eye disease on the intraocular pressure of the Yanomami Tribe Aratha-ú of Roraima State, Brazil, considered endemic for onchocerciasis, a total of 86 patients were submitted to an ophthalmologic exam that included external examination, slit lamp examination, intraocular pressure measurement, and a fundus ophthalmoscope examination. A high prevalence of onchocerciasis-related eye lesions was encountered in 68.6% of the patients. Punctate keratitis and microfilariae in the anterior chamber were found in~28%. The mean of intraocular eye pressure found was 10.47 mm of Hg.

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The Reliability of Anterior Segment Lesions as Indicators of Onchocercal Eye Disease in Guatemala

Cited by 18 publications

References 8 publications

Seventeen Years of Annual Distribution of Ivermectin Has Not Interrupted Onchocerciasis Transmission in North Region, Cameroon

Seventeen Years of Annual Distribution of Ivermectin Has Not Interrupted Onchocerciasis Transmission in North Region, Cameroon

Elimination of onchocerciasis from Colombia: first proof of concept of river blindness elimination in the world

Ocular Onchocerciasis in the Yanomami Communities from Brazilian Amazon: Effects on Intraocular Pressure

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