Graphene film promis­ing for block­ing mos­qui­toes

The Washington Times Weekly - - National - BY SHEN WU TAN

Health of­fi­cials are tout­ing a new pro­tec­tion against blood­suck­ing in­sects amid re­ports of a rare mos­quito-borne dis­ease that has in­fected four peo­ple in Mas­sachusetts, killing one woman.

Re­searchers con­duct­ing a study funded by the Na­tional Institute of En­vi­ron­men­tal Health Sciences dis­cov­ered that a film made of graphene, an el­e­ment found in char­coal and graphite, showed prom­ise in block­ing mos­quito bites.

Dry graphene film ap­peared to in­ter­fere with mos­qui­toes’ abil­ity to de­tect skin and sweat, ac­cord­ing to the study by the Brown Univer­sity Su­per­fund Re­search Cen­ter.

Mos­qui­toes landed much less fre­quently on graphene than on bare skin, re­searchers no­ticed. Graphene also pro­vided a strong bar­rier the in­sects could not bite through.

When wet, how­ever, graphene did not stop mos­qui­toes from land­ing on skin.

“These find­ings could lead to new pro­tec­tive meth­ods against mos­qui­toes, with­out the en­vi­ron­men­tal or hu­man health effects of other chem­i­cal-based re­pel­lents,” said Heather Henry, a health sci­en­tist ad­min­is­tra­tor with the NIEHS Su­per­fund Re­search Pro­gram.

The find­ings fol­low the death of a Mas­sachusetts woman, the fourth per­son in the state that be­came in­fected with Eastern equine en­cephali­tis (EEE), a rare cause of brain in­fec­tions spread by mos­qui­toes.

Con­firmed cases of EEE also have been re­ported in North Carolina and New Jersey. Michi­gan’s health depart­ment has re­ported three sus­pected cases of EEE.

Two dis­cov­er­ies of EEE in mos­qui­toes in Rhode Is­land mo­ti­vated the state health depart­ment to rec­om­mend that schools and mu­nic­i­pal lead­ers sched­ule sports prac­tices and other outdoor ac­tiv­i­ties ei­ther dur­ing early morn­ing or dusk hours or ear­lier in the af­ter­noon to min­i­mize risk of mos­quito bites. The health depart­ment also sug­gested re­lo­cat­ing ac­tiv­i­ties to indoor venues.

Only a few EEE cases are re­ported in the United States each year, with most oc­cur­ring in Eastern or Gulf Coast states, ac­cord­ing to the Cen­ters for Dis­ease Con­trol and Pre­ven­tion.

An aver­age of seven hu­man cases of EEE are re­ported each year to the CDC. About 30% of peo­ple with EEE die and many sur­vivors have on­go­ing neu­ro­logic prob­lems.

“Mos­qui­toes trans­mit a wide va­ri­ety of dis­ease-caus­ing pathogens to hu­mans. Many of these dis­eases have no treat­ment avail­able, and the only way to avoid con­tract­ing them is to avoid be­ing bit by the mos­qui­toes that carry the pathogens,” said Ja­son Ras­gon, pro­fes­sor of dis­ease epi­demi­ol­ogy for Penn­syl­va­nia State Univer­sity.

He said that mos­quito-re­lated in­fec­tions, in­clud­ing Zika and West Nile virus, are gen­er­ally lower this year than in pre­vi­ous years and that the num­ber of EEE cases is in line with num­bers over the last decade, which range from four to a high of 15 cases in 2012.

For this year, the CDC has re­ported 206 cases of West Nile virus, com­pared to 2,647 cases last year. There have been five Zika cases re­ported in U.S. states this year. Last year, states re­ported 74 cases.

“Ob­vi­ously, it is only Au­gust, and 2019 isn’t over yet, but it seems that mosquito­borne in­fec­tions are not as high this year com­pared to pre­vi­ous years,” Dr. Ras­gon said.

Janet C. McAl­lis­ter, re­search en­to­mol­o­gist for the CDC, said mos­quito-re­lated dis­eases come in cy­cles, com­ment­ing on how health re­searchers are not sure why or what sets up a par­tic­u­lar year to have more cases of a dis­ease or not.

“These dis­eases are very, very com­plex be­cause they are not ac­tu­ally a hu­man dis­ease, but a bird dis­ease,” she said, not­ing that re­searchers don’t un­der­stand what drives the cy­cle be­tween birds and mos­qui­toes.

AS­SO­CI­ATED PRESS

Mos­qui­toes land much less fre­quently on graphene than on bare skin, re­searchers found. Graphene pro­vides a strong bar­rier that in­sects could not bite through, thus block­ing mos­quito bites.

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