{"id":142688,"date":"2013-04-08T13:27:09","date_gmt":"2013-04-08T12:27:09","guid":{"rendered":"http:\/\/www.madrimasd.org\/blogs\/universo\/?p=142688"},"modified":"2013-04-09T13:29:00","modified_gmt":"2013-04-09T12:29:00","slug":"suelos-y-compost-reservorios-de-la-gripe-aviar-h5n1","status":"publish","type":"post","link":"https:\/\/www.madrimasd.org\/blogs\/universo\/2013\/04\/08\/142688","title":{"rendered":"Suelos y Compost: reservorios de la Gripe Aviar H5N1"},"content":{"rendered":"

Ya os hemos descrito en numerosas ocasiones que el hombre ha desarrollado potentes tecnolog\u00edas contaminantes, entre las que las que se encuentran la elaboraci\u00f3n de ciertos\u00a0compost<\/a>\u00a0de origen industrial, los lodos de depuradora<\/a>, sustratos vegetales basados en residuos, etc<\/strong><\/span>. La noticia de hoy nos informa que la antiguamente\u00a0temida gripe aviar puede encontrarse agazapada en estos ambientes, obligando a analizar y desinfectar las zonas de riesgo, en aquellos lugares en donde abundan las granjas de aves<\/strong><\/span>. Ya veremos que ocurre en 2013 con la nueva cepa H7N9, o gripe de Shangh\u00e1i<\/a>.\u00a0 Pero sigamos (…) Estudios realizados en Camboya sobre, horizontes de suelos arenosos t\u00edpicos de los arrozales <\/strong>(<\/span><\/span>paddy soils<\/a>) de la zona de estudio, sustratos vegetales basado en compost<\/a>, arenas utilizadas para las construcciones de ciertas zonas, lodos, aguas recolectadas de estanques, plantas acu\u00e1ticas y muestras de suelo, as\u00ed lo constatan. Obviamente, deben darse ciertas condiciones, como que el pH no sea muy \u00e1cido o que los suelos no resulten ser muy arenosos, etc., si bien<\/strong> <\/span>aun es prematuro indicar los h\u00e1bitats adecuados para generar nichos-reservorios de este virus. Eso s\u00ed, los sustratos vegetales\u00a0en base a ciertos residuos y algunos tipos de\u00a0compost parecen, de momento, ser los ambientes con de m\u00e1s alto riesgo de albergar\u00a0estos temidos\u00a0pat\u00f3genos para\u00a0la humanidad<\/strong><\/span>. Se trata de un mundo muy complejo, mientras que yo soy un mero profano en la materia. Por lo tanto, abajo os reproduzco partes de un par de art\u00edculos que posiblemente tan solo sean la punta de un iceberg m\u00e1s\u00a0tenebroso. Cuando comenc\u00e9 mi andadura en este blog, mis conocimientos sobre la relaci\u00f3n entre suelos, agricultura y salud p\u00fablica eran paup\u00e9rrimos. Empero, conforme \u00edbamos editando post, me he topado con numeros\u00edsimas investigaciones que apuntan a que el medio ed\u00e1fico es un reservorio impresionante de pat\u00f3genos, por no hablar de algunos\u00a0compost y los lodos residuales<\/strong><\/span>. \u00a0\u00a0La portentosa y sofisticada tecnolog\u00eda contempor\u00e1nea, se encuentra convirtiendo un bien tan preciado e indispensable para la biosfera y la humanidad, como los recursos ed\u00e1ficos, en un arma que puede llegar a ser letal. \u00a0As\u00ed comienza una de las notas de prensa<\/strong> <\/span>(en suajili<\/em>, es decir la lengua del imperio): \u201cCon vistas a determinar el riesgo potencial de brotes epid\u00e9micos de la gripe aviar (virus H5N1) entre animales de corral y humanos, en la Camboya rural, se recolectaron a muestras de variables ambientales. Se detect\u00f3 la presencia de RNA viral en 27 (35) de 77 muestras de lodo, agua de estanque, plantas de agua y muestras de suelo<\/strong><\/span>. Los resultados subrayan la necesidad de una desinfecci\u00f3n peri\u00f3dica de las \u00e1reas en donde se cr\u00edan aves de corral<\/strong><\/span><\/em>\u201d. \u00a1Qu\u00e9 l\u00e1stima de sociedad! \u00a1Que derroteros tecnol\u00f3gicos tan descarriados! Y que asco de modelo econ\u00f3mico global!. Eso si, notar que el material que reproducimos se encuentra repleto de hiperv\u00ednculos que redirigen a otras p\u00e1ginas web y art\u00edculos de los que pod\u00e9is compilar m\u00e1s informaci\u00f3n al respecto. Veamos ahora que ocurre con la ya aludida H7N9, o gripe de Shangh\u00e1i<\/a>, que \u00abpodr\u00eda\u00bb resultar ser mucho peor que la anteriormente denominada\u00a0gripe aviar<\/a>,\u00a0que tanto nos atemoriz\u00f3 hace muy pocos a\u00f1os, si ciertos datos se confirman.<\/p>\n

Juan Jos\u00e9 Ib\u00e1\u00f1ez<\/strong><\/span><\/p>\n

\u00a0\"gripe-aviar-avian_influenza_h5n1_virus_50271391\"<\/p>\n

Virus de la Gripe Aviar H5N1 Fuente:\u00a0 The 5Th State<\/a>\u00a0<\/p>\n

Contaminated Soil and Transmission of Influenza Virus (H5N1)<\/strong><\/span><\/h2>\n

US National Library of Medicine. National Institutes of Health; Volume 18, Number 9\u2014September 2012 . Letter<\/em><\/p>\n

To determine potential risk for bird-to-human transmission during influenza A virus (H5N1) outbreaks among backyard poultry in rural Cambodia, we collected environmental specimens. Viral RNA was detected in 27 (35%) of 77 specimens of mud, pond water, water plants, and soil swabs. Our results underscore the need for regular disinfection of poultry areas.<\/p>\n

Ver tambi\u00e9n<\/strong><\/span>: Environmental Contamination during Influenza A Virus (H5N1) Outbreaks, Cambodia, 2006<\/a><\/p>\n

\u00a0Et al. 2008. Vong,* Sowath Ly,* Sek Mardy,* Davun Holl,\u2020 and Philippe Buchy*<\/p>\n

Pdf<\/span><\/strong>:\u00a0 Contaminated Soil and Transmission of Influenza Virus (H5N1)<\/a><\/p>\n

Technical appendix<\/a><\/p>\n

Article Contents<\/span>: <\/strong>Letter<\/a>, Acknowledgment<\/a>, References<\/a>, Table<\/a>, Technical Appendix [62 KB – 1 page]<\/a>, Suggested Citation<\/a>, Suggested citation for this article<\/a><\/p>\n

To the Editor:<\/strong> Highly pathogenic avian influenza (HPAI) virus (H5N1)<\/strong> has been responsible for 603 confirmed human cases worldwide, including 356 that resulted in death, and for >7,000 epizootic outbreaks (1<\/a>,2<\/a>). Direct contact between hosts is the main mechanism of transmission for avian influenza viruses, but the possible role of the environment as a source of HPAI virus (H5N1) infection has been rarely studied, particularly in<\/strong> the context of countries where the virus is enzootic or epizootic (3<\/a>\u20137<\/a>). To determine if contaminated soil<\/strong> contributes to the transmission cycle of HPAI virus (H5N1), we used experimental and simulated field conditions to assess possible transmission in chickens. (\u2026)<\/p>\n

We used 3 types of soil: 1<\/strong>) sandy topsoil<\/strong> collected from around rice fields<\/strong> in Phnom Penh Province, Cambodia; 2) building sand purchased <\/strong>from a local building company; and 3) soil-based compost purchased from a local tree nursery<\/strong>. Physicochemical and microbiologic parameters were measured for water extracts obtained for each type of soil (Technical Appendix Table [PDF – 62 KB – 1 page]<\/a>), and low- and high-dose contamination protocols (Technical Appendix Figure [PDF – 62 KB – 1 page]<\/a>) were used to experimentally contaminate each soil type<\/strong>. In brief, we seeded the soil samples with 1\u201356 infectious units of contaminated feces; 1 infectious unit was defined as 1 g feces from an SPF duck mixed with 1 \u00d7 107.8<\/sup> 50% egg infective dose of HPAI virus (H5N1) particles. The contaminated soil was then sprinkled on the bottom of an isolator (surface area 0.2 m2<\/sup>) in which the chickens were housed. Oropharyngeal and cloacal swab samples and feathers were collected daily from the chickens and underwent quantitative reverse transcription PCR<\/strong> (qRT-PCR) testing targeting the H5 hemagglutinin gene (8<\/a>). Surviving birds were killed humanely at the end of the experiments, and postmortem examination and collection of serum and organ samples were conducted on all animals. Organ samples were tested by using qRT-PCR, and serum samples were tested by using hemagglutination inhibition assay (9<\/a>).<\/p>\n

No clinical symptoms, deaths, or seroconversion<\/strong> for HPAI virus (H5N1) were observed in chickens exposed to contaminated sandy topsoil<\/strong>, regardless of the dose protocol used (Table<\/a>). However, for building sand and soil-based compost, the high-dose contamination protocol, starting with 8 infectious units, resulted in a 100% mortality rate by day 4<\/strong>. Low-dose protocols, starting at 1 infectious unit, resulted in survival of all birds at day 24, with no clinical symptoms and no virus detected in the samples collected postmortem. However, seroconversion for HPAI virus (H5N1) was observed in 33% and 50% of the chickens exposed to building sand and compost, respectively <\/strong>(Table<\/a>).<\/p>\n

Soil-based compost and building sand<\/strong>, although existing in natural settings, are not the most common substrates found in places where free-ranging poultry are raised in Cambodia. Therefore, despite the high mortality rate observed in our study after exposure to highly contaminated soils<\/strong>, the role of these soil types<\/strong> in transmission of HPAI virus (H5N1) infection to poultry or other species, including humans, appears limited when replaced in actual epizootic or enzootic field conditions. Our results also show that exposure of chickens to moderately contaminated soil may result in a protective immune response<\/strong>.<\/p>\n

Sandy topsoil<\/strong>, on the other hand, did not allow any transmission of HPAI virus (H5N1) from the environment to chickens. This type of soil, which covers \u224840% of the rice-growing areas of Cambodia<\/strong> (10<\/a>) and is abundant in neighboring countries of the Mekong region, is the most common ground on which local poultry are found wandering and the typical soil found at the sites of HPAI virus (H5N1) outbreaks. This sandy topsoil is acidic and poorly buffered, which explains<\/strong> the differences observed between our indirect pH measures and the direct measures reported in specialized literature (10<\/a>). The soil\u2019s low pH may inactivate enveloped viral particles, as well as bacteria<\/strong> (Technical Appendix Table [PDF – 62 KB – 1 page]<\/a>).<\/p>\n

In Cambodia, as in several other countries affected by HPAI virus (H5N1), decontamination of the environment after an outbreak is recommended<\/strong> by authorities; for example, disinfectants such as cresols are sprayed over environmental surfaces. However, because of resource limitations, only limited areas can be treated. Our results provide evidence that, even when abundantly contaminated, some soil types are unlikely to allow transmission of the virus to poultry and, consequently, probably not to other animals or to humans<\/strong>. These results suggest that limited resources could be better concentrated in high-risk areas<\/strong>, where the nature of the soils<\/strong> would be more likely to lead to poultry infection after natural contamination. These data may aid in the design of more cost-effective and solid-based decontamination measures for preventing transmission of HPAI virus (H5N1) to humans and animals.<\/p>\n

Ramona A. Guti\u00e9rrez and Philippe Buchy<\/p>\n

Author affiliations: Institut Pasteur in Cambodia, Phnom Penh, Cambodia<\/p>\n

Acknowledgment<\/p>\n

This work was supported by the Office of the Assistant Secretary for Preparedness and Response of the US Department of Health and Human Services.<\/p>\n

Table<\/strong>. Clinical, virologic, and serologic results obtained from chickens exposed to soils experimentally contaminated with influenza virus (H5N1) <\/a><\/p>\n

Technical Appendix<\/strong>. [62 KB – 1 page]<\/a><\/p>\n

Suggested citation for this article<\/strong>: Guti\u00e9rrez RA, Buchy P. Contaminated soil and transmission of influenza virus (H5N1) [letter].<\/strong> Emerg Infect Dis [serial on the internet]. 2012 Sep [date cited<\/em>]. http:\/\/dx.doi.org\/10.3201\/eid1809.120402<\/a> DOI: 10.3201\/eid1809.120402<\/p>\n

References<\/strong><\/span><\/p>\n

World Organisation for Animal Health. Outbreaks of highly pathogenic avian influenza (subtype H5N1) in poultry\u2014from the end of 2003 to 7 May 2012 [cited 2012 May 24].<\/p>\n

http:\/\/www.oie.int\/fileadmin\/Home\/eng\/Animal_Health_in_the_World\/docs\/pdf\/graph_avian_influenza\/graphs_HPAI_07_05_2012.pdf <\/a><\/p>\n

World Health Organization. Cumulative number of confirmed human cases for avian influenza A(H5N1) reported to WHO, 2003\u20132012\u2014as of 02 May 2012 [cited 2012 May 24.<\/p>\n

\u00a0http:\/\/www.who.int\/influenza\/human_animal_interface\/EN_GIP_20120502CumulativeNumberH5N1cases.pdf <\/a><\/p>\n

Horm SV, Guti\u00e9rrez RA, Sorn S, Buchy P. Environment: a potential source of animal and human infection with influenza A (H5N1) virus. Influenza Other Respi Viruses. 2012. Epub ahead of print. DOI<\/a><\/p>\n

Indriani R, Samaan G, Gultom A, Loth L, Indryani S, Adjid R, Environmental sampling for avian influenza virus A (H5N1) in live-bird markets, Indonesia. Emerg Infect Dis. 2010;16:1889\u201395.PubMed<\/a><\/p>\n

Leung YHC, Zhang L-J, Chow C-K, Tsang C-L, Ng C-F, Wong C-K, Poultry drinking water for avian influenza surveillance. Emerg Infect Dis. 2007;13:1380\u20132. DOI<\/a> PubMed<\/a><\/p>\n

Stallknecht DE, Goekjian VH, Wilcox BR, Poulson RL, Brown JD. Avian influenza virus in aquatic habitats: what do we need to learn? Avian Dis. 2010;54(Suppl):461\u20135. DOI<\/a>PubMed<\/a><\/p>\n

Vong S, Ly S, Mardy S, Holl D, Buchy P. Environmental contamination during influenza A virus (H5N1) outbreaks, Cambodia, 2006. Emerg Infect Dis. 2008;14:1303\u20135. DOI<\/a> PubMed<\/a><\/p>\n

World Health Organization. Recommendations and laboratory procedures for detection of avian influenza A(H5N1) virus in specimens from suspected human cases. Revised August 2007 [cited 2012 Jan 16].<\/p>\n

http:\/\/www.who.int\/influenza\/resources\/documents\/RecAIlabtestsAug07.pdf\u00a0<\/a>\u00a0 <\/a><\/p>\n

World Organisation for Animal Health. Manual of diagnostics tests and vaccines for terrestrial animals 2010. Chapter 2.3.4: avian influenza [cited 2012 Jan 16]. http:\/\/www.oie.int\/fileadmin\/Home\/eng\/Health_standards\/tahm\/2.03.04_AI.pdf <\/a><\/p>\n

Nesbitt HJ. Rice production in Cambodia. Manila: International Rice Research Institute; 1997.<\/p>\n","protected":false},"excerpt":{"rendered":"

Ya os hemos descrito en numerosas ocasiones que el hombre ha desarrollado potentes tecnolog\u00edas contaminantes, entre las que las que se encuentran la elaboraci\u00f3n de ciertos\u00a0compost\u00a0de origen industrial, los lodos de depuradora, sustratos vegetales basados en residuos, etc. La noticia de hoy nos informa que la antiguamente\u00a0temida gripe aviar puede encontrarse agazapada en estos ambientes, obligando a analizar y desinfectar las zonas de riesgo, en aquellos lugares en donde abundan las granjas de aves. Ya veremos que ocurre en 2013 con la nueva cepa H7N9, o gripe de Shangh\u00e1i.\u00a0 Pero sigamos (…) Estudios realizados en Camboya sobre, horizontes de suelos\u2026<\/p>\n","protected":false},"author":26,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"ngg_post_thumbnail":0},"categories":[596,594,613,592],"tags":[47318,47320,47321,47319,46862],"blocksy_meta":{"styles_descriptor":{"styles":{"desktop":"","tablet":"","mobile":""},"google_fonts":[],"version":4}},"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/www.madrimasd.org\/blogs\/universo\/wp-json\/wp\/v2\/posts\/142688"}],"collection":[{"href":"https:\/\/www.madrimasd.org\/blogs\/universo\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.madrimasd.org\/blogs\/universo\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.madrimasd.org\/blogs\/universo\/wp-json\/wp\/v2\/users\/26"}],"replies":[{"embeddable":true,"href":"https:\/\/www.madrimasd.org\/blogs\/universo\/wp-json\/wp\/v2\/comments?post=142688"}],"version-history":[{"count":10,"href":"https:\/\/www.madrimasd.org\/blogs\/universo\/wp-json\/wp\/v2\/posts\/142688\/revisions"}],"predecessor-version":[{"id":144113,"href":"https:\/\/www.madrimasd.org\/blogs\/universo\/wp-json\/wp\/v2\/posts\/142688\/revisions\/144113"}],"wp:attachment":[{"href":"https:\/\/www.madrimasd.org\/blogs\/universo\/wp-json\/wp\/v2\/media?parent=142688"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.madrimasd.org\/blogs\/universo\/wp-json\/wp\/v2\/categories?post=142688"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.madrimasd.org\/blogs\/universo\/wp-json\/wp\/v2\/tags?post=142688"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}