The Health bulletin [serial] - University of North Carolina at Chapel Hill

i110 THE HEALTH BULLETIN,water in tbe tropics bj' the variousmethods nientioueti is tbe fact that nostagnant water, not even small collectionson a hillside a fourth or aneighth of an inch deep, nor even thewater in a sheep's track, is neglected.Tbe treatment is complete, and this isone of tbe important points that theauthorities in tbe Zone make in dealingwith tbe mosquito problem.VALUE OFSCREENS.If mo.squitoes are allowed to breed,the malarial death rate can be helddown remarkably low by thoroughlyscreening all bouses and by catchingmosquitoes by hand and by traps. Theoccurrence of malaria in the screenedsection and unscreened section of thesame settlement, both sections of whichare equally exposed to the mosquitoes,has demonstrated that there is onethirdless malaria in screened than inunscreened houses. The authorities ofthe Zone stress the point that screeningshould not be done unless it is donethoroughly. An imperfectly screenedhouse frequently serves to admit andretain the mosquitoes, acting as a trap.In screening, an IS-mesh copper wire isused ; a larger mesh will admit of tbeentrance of certain varieties of mosquitoes.The authorities of tbe Canal Zonethink a great deal of catching the mosquito.Mosquitoes are caught in twoways : Wire traps, very much likesome forms of fly traps, are fastenedover the transoms of the doors. Tocatch the mosquitoes entering tbehouse, tbe convex part of the trap isturned in: to catch the mosquitoesleaving the house the position of tbetrap is reversed. A still more importantway than trapping, in catching themosquitoes that reach a dwelling, isby the "band catch." "Hand catching"as carried out in the Canal Zone isdone by ordinary day laborers. Tbemosquitoes are looked for early in themorning, when they are usually foundon the wire screens trying to get out, orlate inthe day in the dark corners oftbe rooms, under shelving, or behindl>ictures. Tbe mosquito catcher carriesa little bicycle lamp and a cylindricalbottle, about 4 inches deep by aninch in diameter, with a little piece vfcotton in the bottom soaked with chloroform.With tbe rays of the lightthrown in tbe dark place he spies themosquito on the wall and graduallyslips the mouth of the bottle over theinsect, which soon becomes anesthetizedand falls into the bottle. In someof the temporary camps, where fillingin and draining are too expensive, ithas been possible to bold tbe malarialdeath rate down to tbe average prevalencein tbe Canal Zone by tbe "handcatch" method. This demonstrates tbeimportance of this measure in controllingthe malarial problem. About tentimes as many mosquitoes are caughtby hand as by traps.The effect of the mosquito work inthe Canal Zone has been to entirelyeradicate yellow fever, the last case ofwhich occurred in lOOG. and to reducemalaria 00 per cent.As will be apparent to our readers,many of tbe methods used in the CanalZone are applicable to North Carolina,and many of the methods used by tbeCanal Zone can be used by the individualfor bis own and his family'sprotection, independently of the iudifferenceof the municipality in whichbe lives to the importance of mosquitoeradication. There are over .oOO deathsand G.'.OOO to 7.5,000 cases of malariaevery year in North Carolina, ninetentbsof which occur in the easternhalf of the State. It is evident that itis time for our people to begin to takean interest in tbe mosquito and malaria.