Malaria: its causes, treatment and methods of prevention20 May, 2005VOL: 101, ISSUE: 20, PAGE NO: 43Joyce Skeet, MSC Trae! Me"#c#$e, %GN, #& 'ract#ce $(r&e, )o!*rook S(r+ery, )or&,a-, .e&tS(&&e/, a$" a -e-*er o0 1T)A, ISTM, a$" t,e %CN Trae! )ea!t, 2or(-T,e .or!" )ea!t, Or+a$#&at#o$ 3.)O4 e&t#-ate& t,at t,ere are *et5ee$ 360 a$" 600 -#!!#o$ ca&e& o0 ac(te -a!ar#a eac, year, ca($+ at !ea&t o$e -#!!#o$ "eat,&, -a#$!y o0 c,#!"re$ ($"er 0#e year& o0 a+e !##$+ #$ &(*7Sa,ara$ A0r#ca 3.or!" )ea!t, Or+a$#8at#o$ a$" t,e U$#te" Nat#o$& C,#!"re$9& 2($", 20064: C,#!"re$ 5,o &(r#e -ay ,ae !ear$#$+ "#00#c(!t#e&, 5,#!e 're+$a$t 5o-e$ are 'art#c(!ar!y (!$era*!e, a$" -ay "ee!o' -ater$a! a$ae-#a a$" -#&carry: Per#$ata! -orta!#ty #& a 0(rt,er r#&k: The World Health Organisation (WHO) estimates that there are between 350 and 500 million cases of acte malaria each year, casing at least one million deaths, mainly of children nder fi!e years of ageli!ing in sb"#aharan $frica (World Health Organi%ation and the &nited 'ations (hildren)s *nd, 2005)+(hildren who sr!i!e may ha!e learning difficlties, while ,regnant women are ,articlarly !lnerable,and may de!elo, maternal anaemia and miscarry+ -erinatal mortality is a frther ris.+ Tra!ellers and torists !isiting contries where malaria is endemic are also at ris.+ Malaria is ,re!entable bt many of those who contract the condition abroad ha!e not ta.en a ,ro,hylactic, ha!e not com,leted the corse or ha!e ta.en ,ro,hyla/is that is nsitable for the area they were !isiting+ .,at #& -a!ar#a;Malaria is a serios tro,ical disease affecting ,eo,le in $frica, #oth and (entral $merica, ,arts of the Middle 0ast and $sia (*ig 1)+ 2t is transmitted by the bite of a female ano,heles mos3ito that has been infected with a malaria ,arasite+ The mos3ito sally bites between snset and snrise, bt in $sia and 4atin $merica the ,ea. of transmission is arond midnight (5assianos, 2001)+ Hmans contract malaria when s,oro%oites ,resent in the sali!a of an infected mos3ito are in6ected into their bloodstream by a mos3ito biting to ta.e a blood meal+ The s,oro%oites infect the li!er cells (he,atocytes) and de!elo, in them o!er the ne/t si/ to 11 days, becoming schi%onts+ When they are matre, the schi%onts brst and release mero%oites into the circlation, which mlti,ly by ase/al fission, some of which then in!ade the red blood cells+ 0ach release coincides with fe!er+ $fter entering the red blood cells, the mero%oites feed on the contents of the cells and some de!elo, into male and female gametocytes+ The life cycle is com,leted when a mos3ito ta.es a blood meal from an infected ,erson who has both male and female gametocytes in the bloodstream, which initiates se/al re,rodction of the ,arasites in the mos3ito)s gt (#teffan and 7-ont, 2001) (*ig 2)+ T,e ca(&e o0 -a!ar#aMalaria is cased by ,arasitic ,lasmodim s,ecies that are carried by the female of an ano,heles mos3ito and introdced into the bloodstream of hmans by an infected mos3ito8 " -lasmodim falci,arm9 " -lasmodim malariae9 " -lasmodim o!ale9 " -lasmodim !i!a/+ The for s,ecies are sometimes referred to as being one of two main forms8 benign or malignant+ The malignant form is the more serios and is cased by -+ falci,arm+ 2t acconts for the ma6ority of infections and is ,otentially life"threatening (:ell, 1;;;)+ Malaria cased by the other three ,lasmodim organisms is generally not life"threatening e/ce,t in the !ery yong, the !ery old, ,eo,le with immnodeficiencies (-ayling, 1;;5)+ 1ree"#$+ 'atter$& o0 t,e -o& days for -+ !i!a/ and -+ o!ale, 12 days for -+ falci,arm and 30 days for -+ malariae (:ell, 1;;;)+ S#+$& a$" &y-'to-&Malaria is sometimes misdiagnosed as inflen%a becase of the sym,toms of fe!er, headache and generalised aches and ,ains+ $ ,yre/ia is common, and some ,atients com,lain of nasea and !omiting, diarrhoea and abdominal cram,s+ (hildren may ,resent with a high tem,eratre, cogh and tachy,noea (ra,id breathing) (5assianos, 2001)+ The li!er and s,leen may be ,al,able and the condition may de!elo, !ery ra,idly9 it often ,ro!es fatal in those infected by -+ falci,arm+ The other malarial infections " -+ malariae, -+ o!ale and -+ !i!a/ " ,resent with malaise, a slowly rising tem,eratre with sweating o!er se!eral days, a headache and nasea+ This cycle may be re,eated daily or e!ery co,le of days+ $n ntreated attac. will !ary in length and rela,ses are common+ ?ela,ses can occr at irreglar inter!als for , to fi!e years+ =#a+$o&0arly diagnosis and treatment is lifesa!ing+ 'early all of the million malaria deaths that occr each year worldwide are from -+ falci,arm, and ;0 ,er cent of deaths from malaria occr in $frica soth of the #ahara, mostly among yong children8 malaria .ills an $frican child e!ery 30 seconds (:ell, 1;;;)+7iagnosis is based on clinical signs and sym,toms and confirmed by e/amining blood films in the laboratory+ At7r#&k +ro('&(hildren and babies are a !ery !lnerable gro, as they de,end on their ,arents to ado,t ,recations to ,re!ent insect bites+ Mos3ito nets shold be sed for children)s beds and cot nets for babies+ Thereare insect re,ellents a!ailable that can be sed for children+ Tra!el to areas where malaria is endemic is best a!oided with babies and yong children if at all ,ossible ((hiodini, 2000)+ -regnant women shold be ad!ised that malaria cold increase the ris. of ,rematre labor and birth,miscarriage and stillbirth+ :ecase malaria is sch a serios illness in ,regnancy and becase no chemo,ro,hylactic regimen is com,letely effecti!e, women who are ,regnant or li.ely to become ,regnant shold be ad!ised to a!oid tra!el to a malaria"ris. area+ 2f a woman mst tra!el she shold be ad!ised to se insect re,ellents s,aringly and slee, nder a mos3ito net+ 2t is safer to ta.e malaria ,ro,hyla/is than to contract malaria (5assianos, 2001)+ $s,lenic ,atients (withot a s,leen) are at ,articlar ris. from malaria+ They mst be aware of the need to se insect re,ellents to ,re!ent bites and concr with the ,ro,hyla/is recommended+ Pree$t#o$-re!ention is described sing the $:(7 rle (:o/ 2) ((hiodini, 1;;;)+ Mos3itoes bite between dawn and ds. so tra!ellers shold be ad!ised to8 " Wear long"slee!e clothing, long trosers or s.irts and limit the amont of e/,osed s.in9 " $!oid dar. colors " mos3itoes are not attracted to light colors9 " 2m,regnate clothing with ,ermethrin soltion+ This shold be carried ot sing a bc.et or ,lastic bag according to the manfactrer)s instrctions+ Mos3ito nets can also be treated in this way ($erbach et al, 1;;;)+ This treatment wor.s well with cotton clothing and it can be washed , to fi!e times after being im,regnated with the soltion+ 2t is recommended that the clothing is not worn in direct contact with the s.in ((ames, 2000)9 " &se a s,ray containing ,ermethrin on clothing+ (lothes shold be s,rayed inside and ot for 30"=0 seconds and allowed to dry for two to for hors before being worn ((ames, 2000)9 " $,,ly insect re,ellents reglarly in cream, s,ray or gel form that contain diethyltolamide (700T)9 " #lee, nder a net im,regnated with ,ermethrin9 " &se coils and mats im,regnated with insecticide in closed rooms to re,el the mos3itoes+ Ma!ar#a 'ro',y!a/#&2nformation abot antimalarial drgs is listed in the :ritish 'ational *ormlary and in manfactrers) ,rodct information+ *ll details of all drgs shold be chec.ed before ,rescribing+ @idelines are also a!ailable to health ,rofessionals wor.ing in tra!el health clinics (see footnote)+ Medical ad!ice shold be soght as soon as ,ossible if there are side"effects from the ,rescribed ,ro,hyla/is, es,ecially if it has been necessary to discontine the medication+ Tra!ellers shold be ad!ised and informed abot what sym,toms to e/,ect if they contract malaria+ On retrn to the &5 they shold be seen in a tra!el clinic or by their @-+ 2t mst be remembered that ,eo,le who ha!e li!ed in the &5 for some years, those who fre3ently goto areas where malaria is endemic or immigrants who retrn to those areas to !isit friends and relati!es, will ha!e no immnity and mst se chemo,ro,hyla/is+ Co$c!(o$Health ,rofessionals mst be able to assess, ad!ise and edcate tra!ellers abot the ,otential ris.s to which they may be e/,osed when they !isit contries where malaria is endemic+ The tra!el health consltation shold be sed as a health ,romotion e/ercise+ 2f tra!ellers nderstand the need to a!oid being bitten by mos3itoes and the im,ortance of chemo,ro,hyla/is they will be more li.ely to ta.e the a,,ro,riate ,recations and retrn well to ,lan their ne/t tri, abroad+