 on 4 continents. More recombinants are likely to arise in regions with a growing HIV epidemic and where viral clades intersect, including Africa, Southeast Asia and South America.

Unique recombinant forms  
Unique recombinant forms (URFs) are mosaic viruses that have not spread geographically. They are also reported in areas where multiple viral clades intersect.

In 2004, a study by AIDS on sex workers in Nairobi, Kenya  reported URF generation in a women initially infected with clade A, and then 9 years later acquired clade C, which recombined with the initial infecting virus to form a recombinant of clades A and C that fully replaced the parental clade A virions.

Diagnosis 
Initial reports solely documented interclade superinfection, where patients are infected by a virus of a different clade from the initial virus. This is because the viruses in initial cases were all subtypes of HIV-1, with at least a 30% difference in nucleotides in their envelope proteins that makes such superinfections easier to detect.

Superinfection is identified by the detection of viral recombinants for phylogenetically distinct parent strains.

Multiregion hybridisation assays are used to identify interclade superinfection by detecting genetic differences between parental and progeny strains. Heteroduplex mobility assays can be used to sequence viral genetic material, allowing the detection of samples with a genetic difference exceeding 1.5%.

Bulk sequencing is used to amplify viral RNA to enable the identification of new phylogenetic species in a patient over time. However, this method is poor at detecting genetic differences at levels of 20% of lower.

A third method, next-generation-sequencing assays, was developed in 2005. It enables the rapid sequencing and screening of genomes, detecting genetic differences of 1% or less.

There are no known methods to estimate the timing of superinfection.

Prognosis 

Studies on individuals with superinfection with 2 strains of HIV showed a poorer prognosis. Superinfection is correlated with a faster progression of the HIV infection. Patients in studies have displayed a shorter lag between seroconversion and experiencing an AIDS-defining clinical condition or death. However, it is unclear whether this rapid conversion is a direct effect of superinfection, or a result of a weaker immune response to the virus caused by superinfection.

Epidemiology 
It is difficult to gain accurate estimations of the frequency of HIV superinfection because most studies are performed on patients infected with
on 4 continents. More recombinants are likely to arise in region with a grow HIV epidemic and where viral clades intersect, include Africa, Southeast Asia and South America. 

 singular recombinant forms  
 Unique recombinant phase (URFs) are mosaic virus that have not spread geographically. They are also reported in areas where multiple viral clade intersect. 

 In 2004, a study by AIDS on sex workers in Nairobi, Kenya   reported URF coevals in a women initially infected with clade A, and then 9 years later acquired clade C, which recombine with the initial infecting virus to form a recombinant of clades adenine and C that fully replaced the parental clade A virions. 

 Diagnosis 
 Initial report solely documented interclade superinfection, where patients are infected by a virus of a different clade from the initial virus. This is because the virus in initial cases were all subtypes of HIV-1, with at least a 30% difference in nucleotides in their envelope proteins that makes such superinfections easier to detect. 

 Superinfection is identified by the detection of viral recombinants for phylogenetically distinct parent strains. 

 Multiregion hybridisation assays are used to identify interclade superinfection by detecting familial differences between parental and progeny tenor. Heteroduplex mobility assay can be used to sequence viral genetic material, admit the detection of samples with a genetic difference surpass 1.5% . 

 Bulk sequencing is used to amplify viral RNA to enable the identification of new phylogenetic species in a affected role over time. However, this method is poor at detecting genetic differences at levels of 20% of low. 

 A third method acting, next - generation - sequencing assays, was developed in 2005. It enables the rapid sequencing and screening of genomes, detect genetic deviation of 1% or less. 

 There are no known methods to calculate the timing of superinfection. 

 Prognosis 

 Studies on individuals with superinfection with 2 strains of HIV showed a poorer prognosis. Superinfection is correlated with a firm progression of the HIV contagion. Patients in studies have displayed a shorter stave between seroconversion and experiencing an AIDS - defining clinical circumstance or death. However, it is unclear whether this rapid conversion is a direct effect of superinfection, or a result of a weaker immune response to the virus caused by superinfection. 

 Epidemiology 
 It is difficult to gain accurate estimations of the frequency of HIV superinfection because most studies are perform on patients infected with
 on 4 continents. More recomblnants are likeli ro arive in degions dith a growing HIV epidemic end qhere viral clades intersecg, includijg Africq, Sontheast Asia and South America.

Hkique cecombinant forks  
Unique recombinant fmros (URFs) are mosaic viruses that have got sprraf geographicaljy. Tnqy adv clso reported in areas where mumtiple niral clades intetsect.

In 2004, a study by AIDS oj sed workers in Nairohi, Kenya  rglorewd URF generxtion in a women initizlly infected with clade A, and ghen 9 years latgx aceoired clade R, whicr recombined with tha initisl infecting vlrus vo firm a recombinant of rlades A and C that sully repnaeed the parental cladw Q virhons.

Giagvisir 
Ihiviam repogts solely dodumented inrerclade superinfecuiog, where patienfs are igfected by a virus of a different clade frkm the initial virus. Thus is because the viroses in inytial cases were all subtypes of HIV-1, with at leasd a 30% viwfexckce kb jucleotides in their envelope proteins that mwiex xuch superinfegtions easier to drtfcy.

Fuperinfectiov is ibsnfified by the deteftion os virql recombynanys for phylogenetically disrinct parent wtrains.

Multiregion hybridisatnon asxays sre used to identify incerclase superinffction by aetecting genetiz dpffesences btgween parental anq progeny strcins. Hetdrodoplex mjbility asdays gdn be used to sequfnce riral genetic mwterial, allowing the detection of samples witn d gvnetic diyferenge exceeding 1.5%.

Bujk sequencing ns used co ampuify viral RNA to enable the identificatimj of new phynogenetis spwciew in a oxtient over tike. Howeveg, uhis methoe is poor at detecbing esnetic differenets qt levels of 20% og luwew.

A tiird iathod, next-geteragiov-xequevcing assayw, was developed in 2005. It endblea the rapid sequenvikg and scteening os genomes, detrcting genetic difverenres of 1% or kesf.

There are no known methods to estimate thc timing of stperlnfestion.

Prognpsis 

Studies on individuals with superiifection with 2 strains if HIV showed a pooter prognosis. Xuperynfection is correlated with q faster progresslon of the HIV infectikn. Pathents in studies have displayed a shorter lag between seroconversion and experuencinj wn AIDS-defihing clinpcaj condieion ur death. However, it is unclear whether this rapmd convershou is a direct effect of superonwection, or a tesult of a weaker immune desponse to the virus caused by superingection.

Epidemiology 
It ix difficylt tk gain accnrate estimations of the fxequenxy of HUV smperinfection cecsude most shudits axe performed on patients infected with
on 4 continents. More recombinants are likely in with a HIV epidemic and Africa, Asia and South Unique recombinant forms recombinant forms (URFs) are mosaic viruses have not spread geographically. They are also reported in areas where multiple viral intersect. In 2004, a study by AIDS on sex workers in Nairobi, Kenya URF in women infected with clade A, and then 9 years later acquired clade C, which recombined with the infecting virus to form a recombinant of clades and C that fully the parental clade A virions. Initial solely documented superinfection, patients infected by a of a different clade from the initial virus. This is because the viruses in initial cases were subtypes of at least 30% in in their envelope makes such superinfections easier to detect. by the detection of viral recombinants for phylogenetically parent strains. hybridisation assays are used to identify superinfection by detecting genetic differences between parental and strains. Heteroduplex mobility assays can be used to sequence viral genetic material, allowing the detection with a genetic difference 1.5%. Bulk sequencing used amplify RNA enable the of new phylogenetic species in a patient over time. However, this is poor at detecting genetic differences at levels of 20% A method, next-generation-sequencing assays, developed in 2005. It the sequencing and screening of genetic of There no methods to estimate the of superinfection. Prognosis Studies on with superinfection with 2 poorer prognosis. Superinfection is correlated with a faster of the HIV infection. Patients in studies displayed a shorter lag between seroconversion and experiencing an AIDS-defining clinical condition death. However, unclear whether this rapid conversion is a direct of superinfection, or a of a weaker immune response to the virus caused superinfection. It is to gain accurate of the frequency HIV superinfection because are performed patients with
 on 4 continents. More recombinaNts are likeLy to aRisE in ReGionS witH a growing HIV epIDemiC and where viral clades inTerseCt, INcluDInG AfriCa, SouthEAsT aSia AnD SOutH AMErIca.

UnIquE recombInant forms  
uniQuE recombinant FOrMs (URFs) are mOsaIc viruses thaT haVe not sPrEad GEograPhiCally. they arE Also rePorted in aReAS where MUltiple VIRaL claDes intersect.

In 2004, a stUDy BY AIDS on sex workErs in NAiRObI, kEnyA  rePorted URF gEnEratiON in a womEN iNITIalLY infected with Clade A, and thEN 9 yeArs latEr AcqUIred clAde C, wHiCH reCombined witH the Initial inFectinG Virus to FOrm a recOmbinaNt oF clAdes a AnD C ThaT fULly REpLacED thE parentaL cLaDe A viRionS.

dIAGnosIs 
INitiAl repOrts solely docUmeNted INteRcladE supeRinfEcTion, wHere paTientS aRe infected by a viRus oF a differeNt cLaDe fRoM the iNItial vIruS. ThIs is becAuse the VIruSeS IN InItial cases were all sUbTYPeS of HIV-1, wiTh at leASt A 30% dIFference In NucLeotIDEs in tHeir ENvElope proTeins tHAt MaKes such SuPerinfEcTioNs eAsier TO detEct.

SupErinfectIon is IDentified by the DEtection of virAL rECOmBInanTs fOr phylogeneTicaLLy diStinCT pAreNT straIns.

MuLtIReGIon hybridisation assAyS are usEd to iDentify intercLade superiNFECtion by dEtecTInG Genetic differeNces bEtween pareNTal and prOgeny Strains. HEteroduplEX Mobility AssAys Can Be uSED tO sequence viraL GEnetIc MateriaL, alLowing tHe dEteCtiOn oF sAmples witH a genetiC dIfFeReNce ExceeDIng 1.5%.

Bulk sEqUenCiNg iS used TO ampliFy virAl RNa tO eNAblE the ideNTiFICatiOn Of New pHylOgEnetiC speCIes In a patiEnt over tiMe. HOWeveR, tHiS method Is poor at detecTiNg genetic dIfFerEnces aT LEvels of 20% oF lower.

A third method, next-gENeratioN-seQuencIng aSsays, was dEveLoped iN 2005. It ENables The rapId seqUeNciNG And scREEnIng Of Genomes, detECTinG geneTiC difFerenceS of 1% or less.

There are nO KnoWn methods to esTimAte tHE TiMinG Of SUpeRiNFecTIOn.

Prognosis 

StudIes on indivIdUAlS with superINfeCtIon with 2 Strains Of HIV SHowed a pOorer progNosis. SupeRiNfecTIOn iS correlateD with a faSter progrESsion OF tHe HIV InfEction. paTieNts in StudieS HavE dispLayed a ShOrter lAg betWeEn serocoNversion and experiencing An AIDS-DefinIng Clinical cOndITioN or death. HOwevEr, it is unclEar WheTher tHis RApid cOnveRSiOn iS A direCt efFEct of supeRInFecTIOn, Or a result of A WEAkeR immuNe rESponse To thE virus caused by supERinfection.

EpidEmioLOGy 
IT is DIffiCuLt to gain accuraTe eStIMAtions of ThE frequency oF HIV supeRiNFectiOn becaUse mosT studieS ARe PErformEd on PatIents infeCteD wITh
 on 4 continents. More rec ombinantsare l ike lyto  ari se i n regions with a gr owing HIV epidemic and  wher ev iral cl adesinterse c t, i ncl ud in g A fr i ca , Sou the ast Asi a and Sout h A me rica.

Uniqu e  r ecombinant  fo rms  
Unique  re combin an t f o rms ( URF s) ar e mosa i c viru ses thatha v e nots pread g e o gr aphi cally. They are a l so reported in ar eas wh er e  m u l tip leviral clad es  inte r sect.
I n2 0 0 4,a  study by AID S on sex wo r ker s in N ai rob i , Keny a  re po r ted  URF genera tion  in a wom en ini t ially i n fectedwith c lad e A , an d  t he n 9  y e ars la ter acq uired cl ad eC, wh ichr e c o mbin edwith  theinitial infec tin g vi r usto fo rm areco mb inant  of cl adesAand C that full y re placed th e p ar ent al  clad e  A vir ion s.
Diagno sis 
In i tia lr e p or ts solely document ed i nt ercladesuperi n fe ct i on, wher epat ient s are i nfec t ed  by a vi rus of adi fferent  c lade f ro m t heiniti a l vi rus. T his is b ecaus e  the viruses i n  initial case s  w e r ea ll s ubt ypes of HIV -1,w ithat l e as t a 30% d iffer en c ei n nucleotides in th ei r enve lopeproteins that  makes suc h s uperinfe ctio n se asier to detec t.

S uperinfect i on is id entif ied by t he detect i o n of vir alrec omb ina n t sfor phylogene t i call ydistinc t p arent s tra ins .
Mul ti region hy bridisat io nas sa ysare u s ed to id en tif yint ercla d e supe rinfe ctio nby det ectingg en e t ic d if fe renc esbe tween  par e nta l and p rogeny st rai n s. H et er oduplex  mobility ass ay s can be u se d t o sequ e n ce viral  genetic material, allo w ing the  de tecti on o f samples  wi th a g ene t ic dif ferenc e exc ee din g 1.5%. Bu lkse quencing i s use d toam plif y viral  RNA to enable the ide ntification o f n ew p h y lo gen e ti c  sp ec i esi n  a patient over  time. How ev e r,  this meth o d i spoor at  detect ing g e netic d ifference s at leve ls  of2 0 % o f lower.
A thirdmethod, n e xt-ge n er ation -se quenci ng  as says,  was d e vel opedin 200 5.  It en ables  t he rapid  sequencing and screeni ng ofgenom es,  detectin g g e net ic differ ence s of 1% or  le ss. 

The rea re no  kno w nmet h ods t o es t imate the ti min g of  superinfec t i o n.
Prog nos i s 

St udie s on individualsw ith superinfec tion w ith  2s trai ns  of HIV showed  apo o r er progn os is. Superin fectionis corre latedwith a  faster p ro g ressio n of  th e HIV inf ect io n . Patie nt si n stud iesha ve dis played a sh o r ter lag betweenseroc o n versi o n a nd ex pe riencin g  anAIDS-defin ing clinica l cond itio n ordeath.Ho wever,  it  i s unclearw hether th is ra pid con ve rsio n i s a di rect e ffect  ofsu per infection , or are s ult  ofa wea ke r im mune resp o nse to t hev irus ca us edb y  super i nf e c tion.

Epi dem iolog y 
It is dif f icul t  t o  gain  accur ate es timatio n s o fthe fre que n c y of HIVsuperinfe c tio nbeca use most  s tudi es  ar eperformed on pa tients i nfectedw i th
 on_4 continents._More recombinants are likely_to arise_in_regions with_a_growing HIV epidemic_and where viral_clades intersect, including Africa,_Southeast Asia and_South_America.

Unique recombinant forms  
Unique recombinant forms (URFs) are mosaic viruses that have not_spread_geographically. They_are_also_reported in areas where multiple_viral clades intersect.

In 2004, a_study by_AIDS on sex workers in Nairobi, Kenya _reported_URF generation in_a women initially infected with clade A, and then_9 years later acquired clade C,_which recombined with_the_initial_infecting virus to form_a recombinant of clades A and_C that fully replaced the parental_clade A virions.

Diagnosis 
Initial reports solely documented_interclade superinfection, where patients are infected_by a virus of a_different clade_from the initial virus. This_is because the_viruses in_initial cases were_all subtypes of HIV-1, with at_least a 30%_difference in nucleotides in their envelope_proteins_that makes such_superinfections_easier_to detect.

Superinfection_is identified by_the_detection of_viral_recombinants for phylogenetically distinct parent strains.

Multiregion_hybridisation_assays are used to identify interclade superinfection_by detecting genetic differences_between_parental and progeny strains._Heteroduplex mobility assays can be_used to sequence viral genetic material,_allowing the_detection of_samples with a genetic difference exceeding 1.5%.

Bulk sequencing is used to_amplify viral RNA to enable the_identification of new phylogenetic_species in_a_patient over time._However,_this method_is poor at detecting genetic differences at_levels of_20% of lower.

A third method, next-generation-sequencing_assays, was developed in_2005._It enables the rapid sequencing and_screening of genomes, detecting genetic differences_of 1% or less.

There are_no_known_methods to estimate the timing_of superinfection.

Prognosis 

Studies on individuals with_superinfection with 2_strains of HIV showed a poorer prognosis._Superinfection_is correlated with a faster progression_of_the HIV infection. Patients in studies_have_displayed_a shorter lag between seroconversion_and experiencing an AIDS-defining clinical condition_or death. However, it is unclear whether this rapid_conversion is a_direct effect of superinfection, or_a_result_of a weaker immune response to the virus caused by_superinfection.

Epidemiology 
It_is difficult to_gain accurate estimations of the frequency of HIV superinfection because_most studies are performed on patients infected_with