RZPORT OW WORK NITH LODSB POWDERS AT TH@ PRISOW AT MUSOW CARRER, ALGERIA. - The opportuBity to uork at the Maiscm Cameo prison mae through the good offioer of Dr. Bdmond Serge, the Diraetor 02 the Pasteur Institute. The first visit to the prisonwas made on July 23rd with Dr. Boguet, who had pre- viously oarried out tests of different types of vrccdaa at the prison. All work ar& observations on louse powder herewith reported Ilam been done by one or more of the group (Dr. Buck, of the Pasteur Institute; Drs.-Davis, Markham, Riehl and Sopsr , of the Rockefeller Foundation) assisted by inmates of the prison working under olose direot supervision. Experiment 1. The initial test at Ihison Carree was planned to seoure data under don- diiona of natural infestation of the co llvr aratire louaioidal aotfon of QWB and IM,, the two louse powders giving the mos favorable resulta in treating arti- fioial infestations. Plarm were made to eliminate as far as poeaihla the in- flwnoe of rainfoatation of the test groups. Outside roiafestation was not on- tir&y prwentible and of oourse any failure of either of the inseatioides pro- vided an epporfunity for internal reinfestation. A preliminary survey of lousiness in Wards I and II, the smle wards of the prison,was nrrde between July 26 and 29th. Propowdering louse counts. July 26 to 29. Ward Number examined With lice With over Peroent Peroent with 9 liee lousy p&b qlioe 1 108 104 77 96 71 2 50 49 99 98 78 ( Total j 158 155 116 g7 73 1 I Ward 1. was ohosen for the first test; Ward 2. to serve as a oontrol against the possibility of a seasonal reduotion of louse inoidece being at- tributed to the use of insaoticide. The 108 men e&nod in Ward 1. were divided into thrse groups of 36 men saeh. The olothing and blau#etr of the men in Group 1. were dusted with a 5 j$ mixtiare of ONE in baqtes (Barium aulphate) produced at Maison Carree and reduab ed with the same material 17 days later; the clothing rmd. blanket6 odthe.mn of Group 2. were dustedtrioe at a 7 day interval with MTL (from a shipmnt arriving in Horth Afrioa in April 1943) and those of group 3. were dusted twioe at an interval of 14 days with MYL from the same shipment. 2. All other inmates of Ward 1. were plaoed in group 4 and treated with 3lYL twios to prevent then from reinfesting the study groups. Plans were made to apply inaa&ioide Mto tha garmants of all nam prisoners oomingto Ward 1. the prison infirmary. and to those returning to the Ward after a stay in do far as is hlowm, tha only persona to aaoape the initial dusting of group 4 were three of the prisoners who assist the guards in the administration of the Ward and 16 sum who work in the bakery. The assistant guards were dusted 3 days, the bakers 13 days after the first dusting of group 4. This failure to dust all of &roup 4 is probably of little importance ainoe these 18 men all anjoy apeoial privileges , are muah olaaner than the ooaaaon run of prisoners aud hare separate quarters. Applioatioa of inaeotioidas. The inseotiaides were applied by dusting frola iylindrioal tins with a row of perforations about the base. Powder was shaken along the seams on the inner surfaces of the olothing and on both idea of the blankets used by the prisoners. The ramoval of olothing is a time oonauming bperation even in prison where the natural reluotanoe to distobe oan be easily oweroome. To avoid this delay and to faoilitate the applioation of powder to the clothing of womenr tests were aulde with one inaaotiaide (0) of'portable blower of the type commonly used in applying powder inrecltioidss to food plants. The initial applioations gave surprisingly good dis- tribution of powder on the inner surfaaes of the olothing dusted in situ. Groupl. Group 2,Group 3. I Group 4. Inseotioide M. Routine Assist Patients 1ns.G Ins. 16 Ins. ?d* from mw group guards Cooks Infirmary prisoners Aug.lT Aug.17 dug.24 Aug.23 Aug.23 dug.24 - --.---~ 14-1s 10 7 10 7-a The olothing and blankets of groups 1, 2 et 3 were exsmirmd at intervals afUr both first and aecrond treatment. Nheraas, in preduating examixaa- tiona, counts were diaoontinued on any given individual when 10 lice had been foundg post treatment exuainations covered the inner surfaces of all the olothing worn, 3. Frisoners with lice T . _ *._ -/ ;roup.3. Group 1. Group 2. Group 3. )rer 9 Lioe c -I--- ex. Pos. 26 I I ,34' 32 23 53 171 34 18 34 24 341 0 34: 0 I 32: 1 33 0 32 1 29 , 1 27' 2 32 19 1 3 0 0 0 0 0 1 1 8 '34 18 34 22 ,34 15 ,12 34/ I IidA ex 32 0 33 0 32, 2 30 2 311 14 - A. - 1 1 5 I i 2 - 3X* A. I. II.' A. I 231 53 211 136 44 115 841 2 0 / 3 76 18 ' 5 00 0 0 10,o 0 8011 0 32 98 23 2 5 21 51 28 - tot FFZF 9 Liee -. I,. - 15 60 1 0 1 - 0 0 '0 0 13 - If. 9 tioe exe Pos. 36 35 26 36 27 35 19 35 1 6 3S i 6 35 6 t 33 2 32 0 33 0 901 l 34 / 11 I 0 0 1 0 13 Relation of oaant to 181 teatment 2-4 days 6-7 days 10 days 13 days 17 days 24 days 30 days 42 days 56 days 63 days 7 8 13 6 1 1 0 0 1 53 0 0 0 0 2 -.- 1o;o 0 0 0'0~ 1 L 0 0 II; 4 0 0 18 110 11 41 36 96 I t instars E t nymphs A t adults Underlining : second treatment The controls in Yard 2. were counted 13 days alfter the first treatment and were found to have suffered no apparent reciuotion in lousiness. The fisst examination of 50 prisoners in Ward 2. revealed 49 infestations of whioh 39 had 10 or more lioe eaoh3 13 dayslater examination of 49 of these re- vealed 48 infestations of whioh 44 were of 10 or more lice each. Examination of 100 prisoners in Ward 2, 26 days after treatment of Ward 1. began, whowed 100 in- festations of whioh 95 were of 10 or more lice oaoh. The controls of other studies oarried out in Xard 2. during the entire period of the later observations in Ward 1. failed to show any rapid diminution in the louse population of untreated individuals. 4. The results of Wperiment I suggest : a. That 5 4 GI?B is slow but certain in its ration. The repetition of the treatment leave8 unsolved the question as to whether the residual GNB in the olothing would have taken oare of the offspring of the 8 adults found 17 days after treatment. b. That HYL kills almost all of the forms present at the time of appliaation but that its full aotivity is limited to a few days. On the other hand, there is some internal evidenoe of aontinued autivity in Group 3. 9 or 10 days. 0. The bulk of all post powdering hatohing ooours during the first d. Apparently a 14 day interval between MYL treatments is not long anough to permit the effeotive development of new eggs by the lice which hatoh out following the first treatment. e* Although earl results of 14 day interval MYL two treatment teohnique do not look ns goo T&i-- ose of the 7 day interval NYL teohnique, the final results at the enl of 83 days are oonslderably better. f. Two treatments of either GNB or MYL can hold a 1ous.e population in oheok for 2 months and GNB at 17 day interval and M?L at a 14 day interval did so for almost three months. (In this oonneotion, time the 83 day oounts were made, it is worth noting that at the the prisoners still considered themselves prao- tioally louse free in oomparisonwith their previous condition).