Ukulwa nezifo ezosulelayo kukhuphiswano lokulwa nokuguquka kwezinto. Iintsholongwane ziyamelana nokubulala iintsholongwane, kwaye iintsholongwane zihlala zitshintsha ukuze zisasazeke ngokukhawuleza. Izifo ezithwalwa zizinambuzane zimele elinye ibala lemfazwe lokuvela kwezinto: izinambuzane ngokwazo ziyamelana noxinzelelo olusetyenziswa ngabantu ukuzibulala.
Ngokukodwa, i-malaria ethwalwa ziingcongconi ibulala abantu abangaphezu kwama-600,000 ngonyaka. Ukususela kwiMfazwe Yehlabathi yesiBini,izibulali-zinambuzane—izixhobo zeekhemikhali ezenzelwe ukubulala iingcongconi zeAnopheles ezisuleleke yintsholongwane yemalariya—ziye zasetyenziswa ukulwa nemalariya.
Nangona kunjalo, iingcongconi zikhawuleza ziphuhlise amaqhinga okwenza ezi zinto zibeizibulali-zinambuzane azisebenzi, nto leyo ebeka izigidi zabantu emngciphekweni omkhulu wokosuleleka okubulalayo. Uphando lwam olusandul’ ukupapashwa, olwenziwe noogxa bam, luchaza isizathu.
Njengengcali yemfuza ephilayo, ndifunda ngokukhetha kwendalo—isiseko sokuguquka okuguquguqukayo. Ukwahluka kwemfuza okuluncedo kakhulu ekusindeni kuthatha indawo yezo zingalunganga, nto leyo ekhokelela kutshintsho kwintlobo ngeentlobo. Amandla okuvela kwengcongconi i-Anopheles ayamangalisa ngokwenene.
Phakathi kwiminyaka yoo-1990, uninzi lweengcongconi zeAnopheles eAfrika zazisengozini yokuhlaselwa ziintshabalalisi zepyrethroid, ezazivela kwichrysanthemums. Ulawulo lweengcongconi lwaluxhomekeke kakhulu kwiindlela ezimbini ezisekelwe kwipyrethroid: inethi zeengcongconi ezinyangwa yiintshabalalisi ukukhusela iingcongconi ezileleyo kunye nezitshizi zezinambuzane ezisele kwiindonga zezakhiwo. Ezi ndlela zimbini zodwa kusenokwenzeka ukuba zithintele iimeko ezingaphezu kwezigidi ezingama-500 zemalariya phakathi kowama-2000 nowama-2015.
Nangona kunjalo, iingcongconi ezivela eGhana ukuya eMalawi ngoku zihlala zikhula ukuxhathisa izibulali-zinambuzane ngobuninzi obuphindwe kalishumi kunedosi eyayinobungozi ngaphambili. Ukongeza kumanyathelo okulawula iingcongconi ze-Anopheles, imisebenzi yezolimo ingazichazi iingcongconi kwi-pyrethroid insecticides, nto leyo eyandisa ukuxhathisa kwazo.
Kwezinye iindawo zaseAfrika, iingcongconi zeAnopheles ziye zakwazi ukumelana neendidi ezine zezibulali-zinambuzane ezisetyenziselwa ukulawula imalariya.
Iingcongconi ze-Anopheles kunye neentsholongwane ze-malaria nazo zifumaneka ngaphandle kwe-Afrika, apho uphando lokuchasana nezibulali-zinambuzane lungaqhelekanga.
Kwiindawo ezininzi eMzantsi Melika, intsholongwane ephambili yemalariya yiAnopheles darlingi mosquito. Le ngcongconi yahlukile kakhulu kwintsholongwane yemalariya eAfrika kangangokuba isenokuba yeyolunye uhlobo—iNyssorhynchus. Ndikunye noogxa bam abavela kumazwe asibhozo, ndihlalutye iigenome zeengcongconi zeAnopheles darlingi ezingaphezu kwe-1,000 ukuze ndiqonde ukwahluka kwazo ngokwemfuza, kuquka naluphi na utshintsho olubangelwe yimisebenzi yabantu yakutshanje. Oogxa bam baqokelele ezi ngcongconi kwiindawo ezili-16 kulo lonke ilizwe elikhulu elisuka kunxweme lweAtlantiki eBrazil ukuya kunxweme lwePasifiki lweeAndes eColombia.
Sifumanise ukuba, njengezihlobo zayo zaseAfrika, *i-Anopheles darlini* ibonisa ukwahluka okukhulu kakhulu kwezakhi zofuzo—ngaphezulu kwezihlandlo ezingama-20 kunezabantu—okubonisa inani elikhulu kakhulu labantu. Iintlobo ezinezakhi zofuzo ezinkulu kangaka zilungelelaniswe kakuhle ukuze zivumelane nemingeni emitsha. Xa inani lilikhulu kangaka, amathuba okuvela kwezakhi zofuzo ezifanelekileyo ezibonelela ngenzuzo enqwenelekayo ayanda. Nje ukuba olu tshintsho luqale ukusasazeka, ngenxa yenzuzo yamanani, kwanokufa okungacwangciswanga kweengcongconi ezimbalwa akuyi kukhokelela ekutshabalaleni kwazo ngokupheleleyo.
Ngokwahlukileyo koko, ukhozi oluneenwele ezinde, oluvela eMelika, aluzange lukwazi ukumelana nesibulali-zinambuzane i-DDT kwaye ekugqibeleni lujongene nokuphela. Ukusebenza kakuhle kwezigidi zezinambuzane kudlula kakhulu oko kweentaka ezimbalwa nje. Enyanisweni, kwiminyaka embalwa edlulileyo, sibone iimpawu zokuguquka okuguquguqukayo kwizakhi zofuzo ezinxulumene nokungamelani namayeza kwiingcongconi ze-Anopheles darlingi.
Iipyrethroids kunye neDDT, phakathi kwezinye izibulali-zinambuzane, zisebenza kwithagethi enye yeemolekyuli: imijelo ye-ion enokuvula nokuvaleka kwiiseli zemithambo-luvo. Xa le mijelo ivuliwe, iiseli zemithambo-luvo zivuselela ezinye iiseli. Izibulali-zinambuzane zinyanzela ezi mijelo ukuba zihlale zivulekile kwaye ziqhubeke nokudlulisa iimpulselelo, nto leyo ekhokelela ekukhubazekeni nasekufeni kwezinambuzane. Nangona kunjalo, izinambuzane zinokulwa nokutshintsha imo yemijelo ngokwazo.
Izifundo zemfuza zangaphambili ezenziwe ngabanye oososayensi, kunye nophando lwethu, azizange zifumane olu hlobo lokuxhathisa kwi-Anopheles darlini. Endaweni yoko, sifumanise ukuba ukuxhathisa kukhula ngendlela eyahlukileyo: ngokusebenzisa iseti yeejini ezifaka ii-enzymes eziqhekeza iikhompawundi ezinetyhefu. Umsebenzi ophezulu wezi enzymes, ezaziwa ngokuba zii-P450s, uhlala unoxanduva lophuhliso lokuxhathisa izibulali-zinambuzane kwezinye iingcongconi. Ukusukela ekufikeni kokusetyenziswa kwezibulali-zinambuzane phakathi kwinkulungwane yama-20, iseti efanayo yeejini ze-P450 iguquke ngokuzimeleyo ubuncinane izihlandlo ezisixhenxe eMzantsi Melika.
EFrench Guiana, olunye useto lwee-genes ze-P450 nalo lubonise ipateni efanayo yokuzivelela, nto leyo eqinisekisa ngakumbi unxibelelwano olusondeleyo phakathi kwezi enzymes kunye nokuziqhelanisa. Ngaphezu koko, xa iingcongconi zazifakwa kwizikhongozeli ezivaliweyo kwaye zivezwe kwi-pyrethroid insecticides, umahluko kwii-genes ze-P450 phakathi kweengcongconi ngazinye wawunxulumene nexesha lazo lokusinda.
EMzantsi Melika, amaphulo amakhulu okulawula imalariya esebenzisa izibulali-zinambuzane ayengahambelani rhoqo kwaye kusenokwenzeka ukuba ayengengoyena mqhubi uphambili wokuvela kwengcongconi. Endaweni yoko, iingcongconi zisenokuba zazichatshazelwe ngokungangqalanga kwizibulali-zinambuzane zezolimo. Okubangela umdla kukuba, sibone iimpawu ezibonakala kakhulu zokuvela kwengcongconi kwimimandla enezolimo eziphuhlileyo.
Nangona kufike amayeza amatsha okugonya kunye nezinye izinto eziphucukileyo ekulawuleni imalariya kwiminyaka yakutshanje, ulawulo lweengcongconi luseyeyona nto iphambili ekunciphiseni ukusasazeka kwemalariya.
Amazwe aliqela avavanya ubunjineli bemfuza ukulwa nemalariya. Le teknoloji ibandakanya ukutshintsha izakhi zofuzo zamaqela eengcongconi ukuze kuncitshiswe inani lazo okanye kuncitshiswe ukumelana kwazo ne-parasite yemalariya. Nangona ukuguquguquka okumangalisayo kweengcongconi kunokubangela umngeni, amathuba ayathembisa.
Mna noogxa bam sisebenza ukuphucula iindlela zokufumanisa ukumelana nezibulali-zinambuzane ezisandula kuvela. Ukulandelelana kweejini kusabalulekile ekufumaneni iimpendulo ezintsha okanye ezingalindelekanga zokuzivelela. Umngcipheko wokuziqhelanisa uphezulu xa uxinzelelo oluhlala ixesha elide nolunzima lokukhetha; ngoko ke, ukunciphisa, ukuguqula, kunye nokunciphisa ukusetyenziswa kwezibulali-zinambuzane kunokunceda ukuthintela uphuhliso lokuxhathisa.
Ukubeka esweni okucwangcisiweyo kunye neempendulo ezifanelekileyo kubalulekile ekulweni notshintsho oluqhubekayo lokunganyangeki kweziyobisi. Ngokungafaniyo nophuhliso lwendalo, abantu bayakwazi ukuxela kwangaphambili ikamva.
UJacob A. Tennessen wafumana inkxaso-mali kwiZiko lezeMpilo leSizwe ngeHarvard TH Chan School of Public Health kunye neBroad Institute.
Ixesha leposi: Epreli-21-2026
