Health briefs

World Heolth r 50lh Yeor. No. I . Jonuorrr-Februory '1997 Heolth briefs Keeping o close wolch on influenzo !u$ how mony of us will cotch influenzo the next lime it comes oround will Jdepend portly on o group of experls who will meet ot WHO in Februory. The group, which meels every yeor, will decide which virus stroins ore likely to be dominont in the next influenzo seoson. Phormoceuticol componies use the groupt odvice when formuloling influenzo voccines. [very yeor influenzo epidemics occur oll over fie world. lt is o potenfiolly fotol diseose, so WHO recommends voccinolion ogoin$ it, especiolly for certoin risk groups - the elderly, people with immunodeficiency, diobetes potients, ond lhose wittr chronic heort or lung diseose, for instonce. However, the voccine is useful only if it is mode from viruses similor to those thot couse the diseose. This seosont voccine formulo is effective ogoin$ B/Beiiing, ArlSingopore ffi I NI) ond A,lWuhon (H3N2) stroins. The expert group will bose its decision obout next seoson's viruses on informulion obout vorionls of influenzo fiom oround the world. lnfluenzo lrends ore monitored by four WHO colloboroting centres (in Austrolio, Jopon, United Kingdom ond USA) ond notionol influenzo loborotories in 83 countries. lf there's o good motch between the voccine ond the virus $roins thot ore in circulofion, eight out of I 0 people who ore voccinoted will be protected ogoin$ ttre diseose ond ih impocton fie re$willbe reduced. Diseoses on lhe woy out oliomyelitis h torgeted for globol erodicofion by the yeor 2000. There ore now I 45 countries completely free of the diseose. leprosy is $eodily being defeoted ond is not expected to be o significont puhlic heolttr problem in o few yeors' time. Guineo-worm diseose (drocunculiosis) is olso well on the woy to erodicolion. Since .l986 the number of coses worldwide hos follen from 3.5 million to obout .l20 000. River blindness (onchocerciosis), coused by o porosite thot is conied by blockflies, is being eliminoted from I I We$Afticon countries. Chogos diseose, o disobling diseose ilrot con couse heort domoge ond deottr in chronic sufferers, is being eliminoted from Argentino, Bolivio, Brozil, (hile, Poroguoy ond Uruguoy. fhe world's biggest killer diseoses f[ bout 52 million people died from oll couses in I 995, occording to theA Woild Heolth Report 1996.0f these, more thon I 7 million were killed by infedious diseoses. Whot ore the I 0 bigge$ killer infecfious diseoses? r Acute lower respirotory troct infecfions - such os pneumonio - killed 4.4 million people, of whom obout 4 million were children. r Dionhoeol diseoses (induding cholero, typhoid ond dysentery), which ore spreod chiefly by contominoted woter or food, killed 3..l million, mo$ of them children. r Tuberculosis killed olmosr 3..l million, induding I million children. r Molorio killed 2.1 million people, induding I million children. r Hepolilis B infecfions killed more thon 1.1 million people. r HIV/AIDS killed more tfion I million people. r Meodes killed more thon I million children. r Neonotol tetonus killed olmo$ 460 000 infonts. r Whooping cough (pertusis) killed 350 000 children. r lntesfinol worm diseoses killed ot leost I 35 000 people. Putting o price on infections fhe domoge coused by infectious diseose omounts to for more thon the I humon toll of ill-heolth ond deoth. lnfections reduce the quolity of life of millions of people, hinder educotion, cul productivity ot work ond use up household resources. Ioking molorio os on exomple, the co$ of 0n overoge cose in sub-Sohoron Africo hos been cokuloted os equivolent to I 2 doys of productive octivity. Studies of the effects of molorio show fiot r in Burkino Foso, eoch cose of molorio cosls more thon I 9 doys of productive outpul; r in Rwondo, the overoge co$ of eoch cose of molorio in I 987 wos eslimoted ot USS I 1.8; r in Sudon, those offected by molorio could not work 1or 220kof the fime during the coune of o yeor; r in Solomon lslonds, eoch child with molorio misses 0n overoge 5.3 doys of school. 0ther diseoses hove their own price. Drocunculiosis, or guineo-worm diseose, costs rice produdion in Nigerio obout I 2% of penondoys thot would oilrerwise be ovoiloble for lobour. ln Rwondo, the co$ of treoting known AIDS coses potenliolly omounts to 60% of the public heolth budget. Ihe overoge medicol expenses ot the fime of on illnes in C0te d'lvoire exceed the fulHime eornings (ot the rote of the minimum woge) lo$ os o result of the illnes. And os osseB such os live$ock ond property hove to be sold to poy for medicol core, 24% of lond tronsoclions in Kenyo ore the result of ill-heolttr. Better heolttr contributes to overoll development, occording t0 Wll0. As o result of WH0! onchocerciosis conlol progromme. which $orted in We$Africo in 1974, more thon 1.7 million odditionol yeon of productive lobour hove become ovoiloble. ln Jomoico, treotment of intestinol helminth infection improved schookhildrent performonce in cognitive function tests ond reduced the number of times they missed school. ln the United Republic of Tonzonio, lreotment of schistosomiosis omong sugor cone cutten increosed productivity. WorldHeolth r 50thYeor, No. l, lonuory-Februory1997 Escherkhio coli ond food poisoning vherkhio rolr is o bocterium thot lives in the inte$ines of onimols ond humon beings. Mo$ $roins of it ore hormless, but some couse more horm thon others. Stroins such os f. colr 0l 5l.Hl ,lu instonce, (0n couse very severe food poisoning, producing toxins similor to those of shigello dysentery. Such stroins ore known os enterohoemorrhogic f. rolr. Ihe 0.l5/:H/ $roin grows in o number of different foods (homburgen, opple cider, cheese, solomi ond cooked moize hove oll been implicoted in 015/:H/ outbreoks) butcon be destroyed by cooking food fill oll porl's reoch o temperoture of 70'I or higher. Cottle seem to be the moin noturol reservoir lor [. coli 015/:H/. Humon beings pick up the bocterium moinly by consuming contominoted foods such 0s rorrv 0r undercooked meot products or row milk. Drinking-woter ond other foods moy be contominoted by foeces. Enterohoemorrhogic f. roficon survive ond grow on solod vegetobles. E. coh0157:H/ couses oomps in the obdomen ond wotery dionhoeo thot con develop into bloody diorrhoeo (hoemorrhogic colitis), os well os fever ond vomiting. Mo$ potients recover in l0 doys but some, especiolly young children ond the elderly, con get dongerous complicotions such os hoemolytic uroemic syndrome. from food is by heoting or irrodiotion. Leishmoniosis ond HIV energe os co-infeclions o-infeclion of viscerol leishmoniosis ond HIV is becoming more (0mm0n 0s AIDS spreods to suburbon ond rurol oreos oround the world. Viscerol leishmoniosis, which is the mo$ serious form of leishmoniosis infection, is endemic in 62 countries ond is spreoding in severol nerrir 0re0s. Around 200 million people live in the endemic oreos ond holf o million new viscerol leishmoniosis coses occur eoch yeor. Leishmoniosis is coused by porosites spreod by sondflies. Ihe commone$form produces skin ulcers on fhe foce, orms ond legs, leoving permonent scors. Another form ottocks the mucous membrones of the nose, mouth ond throot. The viscerol form, which kills mony of those infected if left untreoted, couses feve[ sub$ontiolweight los,0n0emi0, ond swelling of the spleen ond liver. Leishmonio/HlV is considered to be on "emerging diseose", especiolly in southern Europe where 25-70% of odult coses of viscerol leishmoniosis ore reloted to HIV infecfion ond 1.5-9% of AIDS potients hove new or reoctivoted viscerolleishmoniosis. ln this ueo,700/oof coinfected potients ore introvenous drug users. While in on endemic oreo up to one-quorter of the populotion moy be infected but not show symptoms for yeon, the diseose oppeors qukkly when immunity is offected. ln 1995 there were more ihon 1000 leishmonio/HlV co-infections in the Mediterroneon oreo. ln the Americos, mo$ of the co{nfections ore in Brozil. Leishmonio/HlV coinfecfions hove olso been reported in Africo ond Asio. WHO hos set up o network of institutions in I 0 countries to collect informotion on leishmonio/HlV. fosk force will odvise on drug resislonce H0 hos set up o tosk force to keep trock of resistonce to drugs thot ore used to control infections. The losk Force on Resistonce to Anli-infecfive Drugs oims to odvise WHO on motters reloting to diognosis, surveillonce ond the rolionol use of onfi-infecfive drugs; to promote coordinotion of vorious WH0 divisions ond progrommes in this oreo; ond to provide o forum for discussion ond exchonge of informofion. Resistonce to onti-infective drugs (induding onlimicrobiol, ontivirol ond onlimo- loriol drugs) is becoming more frequent oround tfre world. lt is o moior ob$ode to efforls to control o number of infeclious ond porosific diseoses. Severol WHO pr0gr0mmes ore involved in ontimicrobiol resistonre monitoring, contoinment ond the rotionol use of onfi-infeclive drugs. honges in the eortht dimote con do worse thon bring us bod weother. ttrey con be domoging to heolth. Concern obout dimote chonge ond destobilizolion of the worldt ecosystems hos usuolly focused on floods, $orms ond heotwoves. 0n o lorge scole, these would be bod enough, but indirect chonges could toke on even biggertoll ofhumon heolth. Mosquitos ond other insects spreod mony infectious diseoses, including molorio, Africon tryponosomiosis (sleeping sicknes), Americon tryponosomio- sis ((hogos diseose), dengue fever ond plogue. Ihe dimote influences where insects, ond other corriers of diseose, con live ond how eosily they con breed. Foctors such os temperoture, wind, roinfoll, humidiry ovoilobity of surfoce woter, vegetotion ond the presence of predotors oll offect the spreod of the diseose corrie[ ond ofthe diseose itself. A rise in temperoture, for instonce, would meon thot molorio mosquitos ond other corrien of diseose would be oble to spreod t0 new 0reos, infecting new populotions. Ihe proportion of the world's populotion exposed to the risk of molorio could rise in 100 yeors from ttre present 45% to oround 60%. Diseoses such os cholero, ond other infections tronsmitted through woter ond food, would olso be likelyto increose with ttre proliferolion of mkroorgonisms. WH0 Director-Generol Dr Hiroshi Nokoiimo hos colled f0r "new ond better methods for clorifying the relotionship between public heolth ond noturol ond humon-induced dimote chonge". A report on Climote chonge ond humon heolth hos been lointly issued by the United Notions fnvi,on ment Ptogromme, the World Meteorologicol Orgonizolton ond WHO. The 300-page book (order no. 1993aOQl / cosrs Sw.fr 3A. /US $ZZ OO (Sw fr 21 - in developtng counfries) ond is ovoiloble from Distribufion ond So/es, WHO, l2l I Genevo 27, Switzerlond. Climate chonge con domoge your Good hygienic proctices on forms ond in sloughter-houses help reduce f. roli he1lth infedion in milkond meot, butthe onlyeffectivewoyof eliminoling the bocterium