The Prevelance of HIV-1 and HIV-2 Among Patients: An 11 Year Experience at a Tertiary Care Centre

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Published on September 30, 2015

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1. The Prevelance of HIV-1 and HIV-2 Among Patients: An 11 Year Experience at a Tertiary Care Centre

2. Review Article INTRODUCTION Acquired Immuno Deficiency Syndrome is caused by Human ImmunodeficiencyVirus, which since its discovery in 1981 has evolved into a fatal pandemic spreading rapidly all over the world. It spells grave consequences because of its serious impact on social and economic structure of both developed and developing countries, posing a significant challenge to modern medicine and humanity. According to theUnitedNationsjointprogramonHIV/AIDS(UNAIDS), currently there are 33.2 million adults and children living with HIV/AIDS across the world. The highest number of patients is reported from Sub-SaharanAfrica [1,2]. India harbours the second largest number of HIV infections in the world [3]. Where HIV-1 has made its presence felt globally, HIV-2 is more restricted in its distribution.HIV-2infectionisfoundprimarilyinregionsof West Africa, Brazil, and Portugal [4,5]. Guinea-Bissau has thehighestHIV-2prevalenceworldwidewhichrangesfrom 8%-10% in the general adult population [6-9]. HIV-2 has also been reported from European countries neighbouring thewesternAfricancountries.IntroductionofHIV-2inIndia may be related to trading connections between India and Africa. Several states in India have now reported the presenceofHIV-2infectionafterthefirstcasewasreported from Mumbai in 1991 [10]. Methods for detection of HIV have come a long way. These vary from tests that detect the presence of anti-HIV antibody or the HIV antigen or both. The screening tests which detect the presence of antibody are ELISA, particle agglutination and specialized rapid tests whereas confirmatory tests include western blot, immuno- fluoresence(IF)andradioimmunoassay(RIA).Thenucleic acid based tests (PCR) are used to detect the viral nucleic acid. The specialized rapid assays and the western blot are two commonly used assays which differentiate between HIV-1 and HIV-2. Prevalence of HIV-2 has been reported by several studies from Southern and Western part of India; however, notmuchevidenceisforthcomingfromthenorthernpartof our country. The Indraprastha Apollo Hospitals, being a multispeciality tertiary care centre, caters to patients from acrossthecountry,thebulkofwhichisformedbytheNorth 185 Apollo Medicine, Vol. 7, No. 3, September 2010 THE PREVELANCE OF HIV-1 AND HIV-2 AMONG PATIENTS: AN 11 YEAR EXPERIENCE ATATERTIARY CARE CENTRE RN Makroo*, M Chowdhry**, A Bhatia***, B Arora@ and NL Rosamma# *Director,**Associate Consultant,***Registrar,@ DNB-Student, # Senior Technologist, Department of Transfusion Medicine, Indraprastha Apollo Hospitals, Sarita Vihar, New Delhi 110 076, India. Correspondence to: Dr RN Makroo, Director, Department of Transfusion Medicine, Immunology & Molecular Biology, Indraprastha Apollo Hospitals, Sarita Vihar, New Delhi 110 076, India. E-mail: makroo@apollohospitals.com India has the second highest HIV population in the world with about 2.5–3.0 million cases. There are also reports of HIV-2 cases among general and patient population mostly from West and South India. Objectives: To observe the HIV-1 and HIV-2 prevalence among patients at the Indraprastha Apollo Hospitals from 1999-2009. Materials and Methods: A total of 69,510 patients were tested for the presence of HIV infection at our institution over the eleven year period. From 1999 till 2004, a Ortho HIV1/2, Clinical Diagnostics, Johnson & Johnson was used for screening. From 2005 till January 2009 all tests were done using the fourth generation Genscreen HIV1/2, Bio-Rad on a fully automated platform EVOLIS which detected the presence of HIV-1 P24 antigen and anti-HIV antibodies. From February 2009 onwards, the kits used were Genscreen ULTRAHIVAg-AbAssay from Bio-Rad. Results: There were 441 (0.634%) patients were found to be repeat reactive for HIV. 423 (96%) of these 441 reactive patients tested using the Western Blot were found positive for HIV-1 infection. Whereas 18 (4%) patients showed an indeterminate Western Blot result as the test showed the presence of only one envelope band, none of the patients were found reactive for HIV-2 infection. Interpretation & Conclusions: The prevalence of HIV is 0.634% in our study is in accordance with the prevalence found in other reports in literature. No HIV-2 case was found for the last 11 years among our patient population. Key words: HIV-1, HIV-2, Prevalence.

3. Apollo Medicine, Vol. 7, No. 3, September 2010 186 Review Article Indianpopulationandwasthusselectedasthesiteforstudy. MATERIALAND METHODS All the patients (in patients as well a out patients) whose samples were received at the Department of Transfusion Medicine, Indraprastha Apollo Hospitals, New Delhi for testing of anti-HIV antibodies by ELISA from a period ranging from January 1999 to December 2009 were enrolledinthestudy.Atthetimeofreceipt,allrequestswere checked for the presence of patient’s consent for HIV testing. Theabovebloodsamplesweretestedforthepresenceof HIV infection using Enzyme Linked Imunosorbent Assay (ELISA). Period ranging from the year 1999 up till 2004, a third generation ELISA kit (Ortho HIV1/2, Clinical Diagnostics, Johnson & Johnson) was used on a fully automated ARIO walk away system. It detected the presence of anti-HIV antibodies in the serum of patients. From January 2005 till January 2009 all tests were done using the fourth generation ELISA kit (Genscreen HIV1/2, Bio-Rad)whichdetectedthepresenceofHIV-1P24antigen and anti-HIV antibodies on a fully automated platform EVOLIS. From February 2009 onwards, a more sensitive kit (Genscreen ULTRA HIV Ag-Ab Assay from Bio-Rad) was used. Those samples which tested positive by ELISA, were tested again using a fresh sample and the original sample of the patient. If the samples were found repeatedly reactive, they were subjected to Western Blot test using HIV 2.2 Genelab Kit. The Western Blot results were interpreted using the WHO criterion. RESULTS Atotalof69,510patientsweretestedforthepresenceof HIV infection using the ELISA technique at our institution over the eleven year period. Of these 59,084 (85%) patients were males and 10,426 (15%) patients were females. Of these 446 (0.641%) patients were found to be initially reactive for HIV infection. Upon repeat testing in duplicate 441 (0.634%) patients were found to be reactive. These included 245 (249 initial reactive) patients from 1999-2004 when third generation HIV ELISA kits (Ortho HIV1/2, Clinical Diagnostics, Johnson & Johnson) were used and 196 (197 initial reactive) patients when fourth generation kits (Genscreen, Bio-Rad) were used. Males formed the major chunk of the reactive population comprising around 84.8% (374/441), whereas, only a small proportion of positive cases turned out to be females 15.2% (67/441) (Fig. 1). A high rate of HIV positivity 47.1% (208/441) was seen with people in the age group of 21-30 years and a small fraction 4.9% (22/441) were in the age category of over 50 years. The 31-40 year oldsshowedthesecondhighestclusteringofHIVpositives, i.e.27.2%(120/441)followedby13.8%(61/441)intheage range of 41-50 years. Only 6.8% (30/441) cases were less than 20 years of age (Fig. 2). All the 441 patients who were found to be positive on repeat testing were further tested by Western Blot. The WHO criterion was used for the interpretation of the WesternBlotresult.Thecriterionrequiresthepresenceofat least 2 envelope bands (gp 160, gp120, gp41) with or without the presence of gag and pol gene products. 423 (96%)ofthe441patientstestedusingtheWesternBlotwere found positive for HIV-1 infection. Whereas 18 (4%) patients showed an indeterminateWestern Blot result as the test showed the presence of only one envelope band ( either gp 160 or gp 120 or gp 41). None of the patients were found reactive for HIV-2 infection. The trend of the HIV infection among the patient population at our hospital over the past eleven years from 1999-2009 has been depicted in Fig. 3. Fig. 1. Showing the percentage of infected males and females. Fig. 2. Showing the age distribution of the infected patients.

4. Review Article 187 Apollo Medicine, Vol. 7, No. 3, September 2010 DISCUSSION ThefirstdocumentedHIVinfectioninIndiawasamong a sex worker in Chennai, Tamil Nadu, in 1986 [11,12]. The virus since then has been spreading rapidly across the country. States with a high prevalence of HIV where prevalence of HIV infection is 1% or higher in antenatal women include Maharashtra, Tamil Nadu, Karnataka, Andhra Pradesh, Manipur, and Nagaland [1,11]. Within these high-prevalence areas, the HIV epidemic reflects diverse social, cultural, religious, and sexual practices [13,14].There are “hot spots,” where commercial sex work is common, such as in coastal Andhra Pradesh, Northern Karnataka, and Southern Maharashtra [13]. EpidemiologyofHumanImmunodeficiencyVirusType 2 (HIV-2) on the other hand is much varied. Ever since its first occurrence from Senegal, West Africa in 1986 [15], many incidences of HIV-2 infection have been reported from various parts of the world. Over the past decade significant cases of HIV-2 infection have been reported from most West African countries [16,17]. Prevalence of HIV-2 in these regions is morethan1%[15].AsecondepidemiologicpatternofHIV- 2 infection has been proposed from reports of HIV-2 in Portugal, Mozambique, Angola, South-Western India and Brazil, all areas with former ties to Portugal [16,18,19]. Exceedingly low HIV-2 prevalence rates have been reported from other parts of Africa, Europe, the Americas, the Middle East andAsia [16]. Though HIV-1 and HIV-2 are genetically and antigenically related viruses, they posses distinct epidemiological and biological characteristics.The viruses share 40-50% genetic homology, major antigenic cross- reactivity in viral structural gene products, similar genetic organization and cell tropism [16,20]. Extensive epidemiological and natural history studies doneonHIV-2havecontributedtoourwealthofknowledge pertaining to the novel properties of this virus. Some of theseuniquepropertiesincludeadistinctglobaldistribution of the virus with limited spread, significantly reduced perinatal and sexual transmission, slower rates of progression to AIDS and the potential protective effect of HIV-2 from subsequent HIV-1 infection [16] . Epidemiological and natural history studies conducted on HIV-2 are largely dependent on accurate diagnosis of HIV-2 viral infection. The same testing procedures that were developed for HIV-1 for serologic testing, virus culture and genetic diagnostics such as polymerase chain reaction(PCR)havebeenmodifiedandimprovedforHIV-2 diagnosis over the years. The close relationship that HIV-1 and HIV-2 share on a genetic and antigenic level has necessitated the development and implementation of type- specific diagnostic assays. HIV ELISA assays available commercially most commonly include both HIV-1 and HIV-2antigensforscreeningpurposes.ThereactiveELISA results are typically confirmed using Western Blots or Immunoblots, which contain an array of major structural gene product blotted on a solid support and interpreted using a standard criterion [16]. In our study all patients from 1999-2004 were screened using the third generation ELISA kits (Ortho HIV 1/2 Clinical Diagnostics, Johnson & Johnson) which detected anti-HIV antibodies. Fourth generation Elisa kit (Genscreen, Bio-Rad) was introduced from year 2005 which was an antigen-antibody combo kit detecting the presence of P24 antigen along with anti-HIV antibodies. Theswitchfromthirdtofourthgenerationassaysresultedin decrease rate of false positivity and hence, increased specificity. The specificity increased from 98.3% (245 out of 249 were repeat reactive) to 99.4% (196 out of 197 showing repeat reactivity). According to the National AIDS Control Organization (NACO), the overall viral prevalence among general adult population of India remains at 0.36% as of 2006 which translatestoapproximately2.5-3.0millioncases[3,21,22]. In our study the prevalence of HIV among our patient population was found to be 0.641% (446/69,510) using serologicaltests(thirdandfourthgenerationELISA)which is comparable with other data. As compared to African countries, the significantly low levels of viral incidence in India are not completely understood. Socio-economic conditions, cultural factors, host genetics and family traditionsmaybepostulatedtohaveplayedorareplayingan importantrole[3].Theroleofsocio-economicconditionsin the viral transmission is evident within the Indian population as well, with disease prevalence being significantlyhigherinruralthanurbanpopulation.Asurvey of households in Tamil Nadu found that 2.1% of the adult Fig.3. Sero prevalence of HIV among the patient population of North India from 1999- 2009.

5. Apollo Medicine, Vol. 7, No. 3, September 2010 188 Review Article rural population living in that part of the country had HIV infection compared with 0.7% of the urban population. [11,23]. However, among the high risk population, including intravenous drug users (IDU), men who have sex with men (MSM) and commercial sex workers (CSW), the infection rates are higher than 5% (NACO, India), suggesting that host resistance may have a limited significance [3]. The epicentre of HIV-2 infection has been postulated to beinWestAfrica[24-26],however,theprevalenceofHIV-2 is growing in many parts of the world especially those countries with past socio-economical links with Portugal including southwest India [27-30]. Portugal has the highest prevalence of HIV-2 infection in Europe, accounting for around 10-13% of total HIV infections and 4·5% of AIDS cases [27,31]. In Guinea-Bissau, a former Portuguese colony, there is an HIV-2 prevalence of up to 8-10% [27,32,33]. Surrounding countries including The Gambia, Senegal and Guinea have been projected to have a lower prevalence rate of 1-2%, although the prevalence among commercial sex workers in The Gambia is as high as 28% [27]. Other countries with a significant numbers of HIV-2 infections areAngola, Mozambique and Brazil [27]. ThereareseveralcitationsstatingthepresenceofHIV-2 in south-western part of India, whereas not much data is available from the northern part of the country. A study conducted on five urban and five rural population of Tamil Nadu has reported the sero-prevalence of HIV-2 mono infection to be 0.1% whereas, the prevalence of dual infection (both HIV-1 and HIV-2) is 0.44% .[10,34]. Prevalenceratesof1.3%forHIV-2monotypicinfectionand 1.5% for HIV-1 and HIV-2 dual infection were reported from another study conducted over a period of 10 years at a bloodbankofatertiarycarecentreofsouthernIndia[10].In our study we did not find a single case of HIV-2. The 441 patients found to be repeat reactive were confirmed using a WesternBlottest.ThetestswereinterpretedusingtheWHO criterion. We found 96% (423/441) seropositive patients to be infected with HIV-1 virus. None was found to be harbouring HIV-2. The indeterminate results using this criterion were to the tune of 4% (18/441). Another study conducted between April 1994 and March 1995, on representative urban and rural population ofTamil Nadu the prevalence of HIVinfection in urban and ruralareas was 7.2%. HIV-1 antibodies werefound in 7.4% of urban and 7.0% of rural population; HIV-2 antibodies were found in 0.8% of urban and 0.3% of rural population [34]. This situation differs from the situation in North India asreflectedfromourstudy,wherenotonlytheprevalenceof HIVis less in general population (0.641%), no case of HIV- 2hasbeendetected.AhighprevalenceofHIV-2wasseenin a group of high risk individuals (patients of a sexually transmitted disease clinic and the GT hospital in Mumbai) inastudyconductedatMumbai.Therateofmonoinfection withHIV-2was4%andthatofdualinfectionwas20%[35]. According to NACO, more men are HIV positive than women. Nationally, the prevalence rate for adult females is 0.29 percent, while for males it is 0.43 percent. In our study, 15.2% (67/441) females tested positive for HIV as compared to males who were in majority, showing a high positivity of 84.8% (374/441) (Fig. 3). “Actions from the youth, advice from the middle aged, prayers from the aged.” The old proverb highlights the age distribution of our HIV positive population with a high rate of HIV positivity, 47.1% (208/441) in the age group of 21- 30 years and a small fraction 4.9% (22/441) in the age category of over 50 years. The 31-40 year olds showed the secondhighestclusteringofHIVpositives,i.e.27.2%(120/ 441) followed by 13.8% (61/441) in the age range of 41-50 years. Only 6.8% (30/441) cases were less than 20 years of age (Fig. 2). The trend as we observed of HIV over the past eleven years was in accordance with that of the other studies. 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