Biomaterial Database

Successful interruption of transmission of Onchocerca volvulus in the Escuintla-Guatemala focus, Guatemala. 2009

Rodrigo J Gonzalez, and Nancy Cruz-Ortiz, and Nidia Rizzo, and Jane Richards, and Guillermo Zea-Flores, and Alfredo Domínguez, and Mauricio Sauerbrey, and Eduardo Catú, and Orlando Oliva, and Frank O Richards, and Kim A Lindblade

Centro de Estudios en Salud, Universidad del Valle de Guatemala, Guatemala City, Guatemala.

BACKGROUND Elimination of onchocerciasis (river blindness) through mass administration of ivermectin in the six countries in Latin America where it is endemic is considered feasible due to the relatively small size and geographic isolation of endemic foci. We evaluated whether transmission of onchocerciasis has been interrupted in the endemic focus of Escuintla-Guatemala in Guatemala, based on World Health Organization criteria for the certification of elimination of onchocerciasis. RESULTS We conducted evaluations of ocular morbidity and past exposure to Onchocerca volvulus in the human population, while potential vectors (Simulium ochraceum) were captured and tested for O. volvulus DNA; all of the evaluations were carried out in potentially endemic communities (PEC; those with a history of actual or suspected transmission or those currently under semiannual mass treatment with ivermectin) within the focus. The prevalence of microfilariae in the anterior segment of the eye in 329 individuals (> or =7 years old, resident in the PEC for at least 5 years) was 0% (one-sided 95% confidence interval [CI] 0-0.9%). The prevalence of antibodies to a recombinant O. volvulus antigen (Ov-16) in 6,432 school children (aged 6 to 12 years old) was 0% (one-sided 95% IC 0-0.05%). Out of a total of 14,099 S. ochraceum tested for O. volvulus DNA, none was positive (95% CI 0-0.01%). The seasonal transmission potential was, therefore, 0 infective stage larvae per person per season. CONCLUSIONS Based on these evaluations, transmission of onchocerciasis in the Escuintla-Guatemala focus has been successfully interrupted. Although this is the second onchocerciasis focus in Latin America to have demonstrated interruption of transmission, it is the first focus with a well-documented history of intense transmission to have eliminated O. volvulus.

UI	MeSH Term	Description	Entries
D007303	Insect Vectors	Insects that transmit infective organisms from one host to another or from an inanimate reservoir to an animate host.	Insect Vector,Vector, Insect,Vectors, Insect
D007559	Ivermectin	A mixture of mostly avermectin H2B1a (RN 71827-03-7) with some avermectin H2B1b (RN 70209-81-3), which are macrolides from STREPTOMYCES avermitilis. It binds glutamate-gated chloride channel to cause increased permeability and hyperpolarization of nerve and muscle cells. It also interacts with other CHLORIDE CHANNELS. It is a broad spectrum antiparasitic that is active against microfilariae of ONCHOCERCA VOLVULUS but not the adult form.	Eqvalan,Ivomec,MK-933,Mectizan,Stromectol,MK 933,MK933
D008297	Male		Males
D009855	Onchocerciasis	Infection with nematodes of the genus ONCHOCERCA. Characteristics include the presence of firm subcutaneous nodules filled with adult worms, PRURITUS, and ocular lesions.	Onchocerciases
D002648	Child	A person 6 to 12 years of age. An individual 2 to 5 years old is CHILD, PRESCHOOL.	Children
D003140	Communicable Disease Control	Programs of surveillance designed to prevent the transmission of disease by any means from person to person or from animal to man.	Flatten the Curve of Epidemic,Flattening the Curve, Communicable Disease Control,Parasite Control,Control, Communicable Disease,Control, Parasite
D003906	Developing Countries	Countries in the process of change with economic growth, that is, an increase in production, per capita consumption, and income. The process of economic growth involves better utilization of natural and human resources, which results in a change in the social, political, and economic structures.	LMICs,Less-Developed Countries,Low Income Countries,Low and Middle Income Countries,Lower-Middle-Income Country,Middle Income Countries,Third-World Countries,Under-Developed Countries,Developing Nations,Least Developed Countries,Less-Developed Nations,Third-World Nations,Under-Developed Nations,Countries, Middle Income,Countries, Third-World,Country, Least Developed,Country, Less-Developed,Country, Low Income,Country, Lower-Middle-Income,Country, Middle Income,Country, Third-World,Country, Under-Developed,Developed Country, Least,Developing Country,Developing Nation,Least Developed Country,Less Developed Countries,Less Developed Nations,Less-Developed Country,Less-Developed Nation,Low Income Country,Lower Middle Income Country,Lower-Middle-Income Countries,Middle Income Country,Nation, Less-Developed,Nation, Third-World,Nation, Under-Developed,Third World Countries,Third World Nations,Third-World Country,Third-World Nation,Under Developed Countries,Under Developed Nations,Under-Developed Country,Under-Developed Nation
D005260	Female		Females
D006166	Guatemala	A country in CENTRAL AMERICA bordering the North Pacific Ocean, between EL SALVADOR and MEXICO, and bordering the Gulf of Honduras (Caribbean Sea) between HONDURAS and BELIZE.
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man