| [new description of onchocerca volvulus (leuckart 1894) railliet and henry 1910, from chiapas, mexico]. | | 1976 | 1005960 |
| [entomology of onchocercosis in soconusco, chiapas. 6. quantitative studies of the transmission of onchocerca volvulus by 3 species of simuliidae in a community with high endemicity]. | in guatemala, there is no doubt about the participation of simulium ochraceum as vector of onchocerciasis. however, in mexico practically there are not studies focussed to determine the role of this species in the transmission. the objective of the present investigation was to determine which of the 3 species of simulium founded in the soconusco region of chiapas, is the main, and which were secondary in the transmission of onchocerciasis in that area. the locality of morelos, in the huixtla "mu ... | 1992 | 1345118 |
| [entomology of onchocerciasis in soconusco, chiapas, méxico. vii. quantitative variations in the transmission of onchocerca volvulus (nematoda: filaroiidea) according to human activity space]. | in this research we tried to demonstrate differences in transmission intensities of onchocerciasis by simulium ochraceum in the community of golondrinas, municipality of acacoyagua in the soconusco area of the state of chiapas. adult females of this species were captured in the center of the villages, the coffee plantation, and the corn bean planted plots, during 7 to 10 consecutive days of the months of june, august, november and december of 1983, and january, march, and may of 1984. captures w ... | 1991 | 1844134 |
| [the correlation between onchocercomas and positivity for microfilaria in onchocerciasis]. | the objective of this work is to evaluate the palpation sensitivity of onchocercomata for the diagnosis of onchocerciasis in individuals residents of the locality of nueva costa rica, mapastepec, in the south endemic area of the state of chiapas, mexico. every one of the 243 individuals who voluntarily participate in this study was interrogated and physical examined for the detection of nodules. the positivity and the worm burden to the onchocerca volvulus infections was estimated by the presenc ... | 1990 | 2089642 |
| [immunoenzymatic evaluation of serum ige in onchocerciasis in chiapas, mexico]. | concentrations of total serum ige were measured by an immunoenzymatic assay (phadezym-prist) in 60 mexican onchocerciasis patients. in order to detect ige antibodies against adult onchocerca volvulus antigens, separately six onchocerciasis sera were depleted of ige antibodies by using a mixture of onchocerca gutturosa, ascaris suum and fasciola hepatica antigenic extracts coupled with sepharose 4b. additionally, the sera were incubated with an adult o. volvulus antigenic extract coupled with sep ... | 1989 | 2697095 |
| [the effect of ivermectin on the transmission of onchocerca volvulus in southern mexico]. | we assessed the transmission potential and the mean infected and infective biting density of s. ochraceum in an onchocerciasis endemic community in the southern mexican state of chiapas. in addition, the impact of first treatment of ivermectin during the peak of natural infection of host-seeking s. ochraceum populations was also evaluated. monthly entomological sampling was carried out during the year before treatment to assess the seasonal biting behavior of parous host-seeking s. ochraceum fem ... | 1994 | 7940009 |
| polymerase chain reaction monitoring of transmission of onchocerca volvulus in two endemic states in mexico. | to investigate the impact of mass ivermectin treatments in mexico on onchocerca volvulus transmission, entomologic surveys were carried out in the two endemic states of oaxaca and chiapas. the data suggest that substantial progress towards the goal of elimination has been made. a comparison pre- and post-ivermectin data from a community in southern chiapas showed a 97% decrease in seasonal transmission potential, but some level of polymerase chain reaction positivity was still detectable. in oth ... | 2004 | 14971696 |
| molecular studies of onchocerca volvulus isolates from mexico. | dna from onchocerca volvulus from oaxaca and chiapas, mexico were used as templates to amplify members of the o-150 onchocerca specific repeat sequence family. the resulting pcr amplicons all hybridized with ovs2, an oligonucleotide that has been previously shown to recognize amplicons derived from o. volvulus with 100% sensitivity. however, when pcr products amplified from the o. volvulus specific plasmid povs134 were used as a probe, most samples did not hybridize. similarly, when pcr products ... | 2006 | 15919244 |
| large-scale entomologic assessment of onchocerca volvulus transmission by poolscreen pcr in mexico. | to study the impact of mass mectizan treatment on onchocerca volvulus transmission in mexico, entomological surveys were carried out in the endemic foci of oaxaca, southern chiapas, and northern chiapas. collected flies were screened by polymerase chain reaction (pcr) for o. volvulus parasites. the prevalence of infected and infective flies was estimated using the poolscreen algorithm and with a novel probability-based method. o. volvulus infective larvae were not detected in flies from 6/13 com ... | 2006 | 16760515 |
| analysis of genetic variation in ribosomal dna internal transcribed spacer and the nadh dehydrogenase subunit 4 mitochondrial genes of the onchocerciasis vector simulium ochraceum. | onchocerciasis is a serious disease vectored by black flies in the genus simulium that are infected with the filarial parasite onchocerca volvulus. in the americas, black flies of the simulium ochraceum s.l. species complex are important vectors of this parasite. cytological studies have suggested that this species complex consists of at least three cytotypes that inhabit distinct habitats. in this study, the nadh dehydrogenase subunit four (nd4) and internal transcribed spacer (its) of the ribo ... | 2006 | 16892627 |
| rapid suppression of onchocerca volvulus transmission in two communities of the southern chiapas focus, mexico, achieved by quarterly treatments with mectizan. | the impact of quarterly mectizan (ivermectin) treatments on transmission, microfiladermia, and ocular lesions was evaluated in two formerly hyperendemic communities (las golondrinas and las nubes ii) located in the main endemic focus for onchocerciasis in southern chiapas, mexico. the data suggest that onchocerca volvulus transmission has been suppressed after elimination of microfiladermia in these two communities. increasing the frequency of mectizan treatment to four times per year appears to ... | 2008 | 18689630 |
| lack of active onchocerca volvulus transmission in the northern chiapas focus of mexico. | the northern chiapas onchocerciasis focus has undergone 11 years of ivermectin mass treatment. no evidence of microfilariae in the cornea and/or anterior chamber of the eye or in skin snips was seen in residents examined in 2006 in two sentinel communities (upper limit of the 95% confidence interval [ul 95% ci] = 0.5% and 0.3%, respectively). in children 10 and under, 0 of 305 were found to harbor antibodies to ov16, a marker of parasite exposure; 0 of 4,400 simulium ochraceum s.l. collected in ... | 2010 | 20595471 |
| interruption of transmission of onchocerca volvulus in the southern chiapas focus, méxico. | the southern chiapas focus of onchocerciasis in southern mexico represents one of the major onchocerciasis foci in latin america. all 559 endemic communities of this focus have undergone semi-annual mass treatment with ivermectin since 1998. in 50 communities of this focus, ivermectin frequency shifted from twice to four times a year in 2003; an additional 113 communities were added to the quarterly treatment regimen in 2009 to achieve a rapid suppression of transmission. | 2013 | 23556018 |
| morphometric analysis of nodules in human onchocerciasis collected in communities of the southern chiapas focus, méxico. | human onchocerciasis is a disease that remains as an important public health problem. the morphometric and physical characteristics of 363 onchocerca volvulus nodules collected in the major endemic focus of onchocerciasis in southern chiapas (soconusco), was assessed. in the present work we found that treatment the morphometry of 363 onchocercal nodules preserved in a 67% glycerol solution was determined by measuring the length, width and thick of each nodule with a vernier caliper. the mass was ... | 2012 | 22662599 |