We report the results of seroepidemiological survey of Human immunodeficiency virus (HIV), Hepatitis B virus (HBV) and Hepatitis C virus (HCV) infections among the Karen, La-Wah and Lahu-Na, designated as the hill tribes, in northern Thailand. Some of these hill tribes are living in the remote and isolated mountain areas, settling their own communities. Anti-HIV seropositive cases were found only in the Lahu-Na (2.6%). The highest incidence of Hepatitis B surface antigen (HBs-Ag) positive was found in the Karen (13.2%), followed by the Lahu-Na (2.6%) and the La-Wah (1.7%). The highest incidence of anti-Hepatitis C virus antibody (anti-HCV) positive was found in the La-Wah (3.3%), followed by the Karen and the Lahu-Na (2.6%, respectively). Two out of nine anti-HCV positive cases were from seven and 11 year-old Karenean girls, who had no previous history of surgery, blood transfusion, intravenous medication, vaccination and dental therapy. These results suggest that HIV infections have not yet reached to the hill tribes, except the Lahu-Na. One of the possible transmission routes of HCV infection is a vertical or intrahhousehold infection among the hill tribes in northern Thailand

Itakura Hideyo

Jiviriyawat Yupa

Jutavijittum Prapan

Kusuda Masako

Toriyama Kan

Vanittanakom Pramote

Yousukh Amnat

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Trop. Med., 38 (2), 79-86, June, 1996　　　　　　　　　　　　　　　　　　　　　　　　　　　79Seroepidemiological Survey of Human ImmunodeficiencyVirus (HIV), Hepatitis B Virus (HBV) and Hepatitis CVirus (HCV) Infections among The Hill Tribesin Northern ThailandKan TORIYAMA1. Amnat YOUSUKH2, Yupa JIVIRIYAWAT2,Prapan JUTAVIJITTUM2, Pramote VANITTANAKOM2,Masako KUSUDA1, and Hideyo ITAKURA11Dφartment of Pathology, Institute of Tropical Medicine, NagasakiUniversity, 1 - 12-4 Sakamoto, Nagasaki 852, Japan2Dφartmeni of Pathology, Faculty of Medicine, Chiang Mai University,110 Intavaroros Rd., Chiang Mai 50200, ThailandAbstract: We report the results of seroepidemiological survey of Human im-munodeficiency virus (HIV), Hepatitis B virus (HBV) and Hepatitis C virus (HCV) in-fections among the Karen, La-Wah and Lahu-Na, designated as the hill tribes, innorthern Thailand. Some of these hill tribes are living in the remote and isolatedmountain areas, settling their own communities. Anti-HIV seropositive cases were foundonly in the Lahu-Na (2.6%). The highest incidence of Hepatitis B surface antigen(HBs-Ag) positive was found in the Karen (13.2%), followed by the Lahu-Na (2.6%) andthe La-Wah (1.7%). The highest incidence of anti-Hepatitis C virus antibody (anti-HCV)positive was found in the La-Wah (3.3%), followed by the Karen and the Lahu-Na(2.6%, respectively). Two out of nine anti-HCV positive cases were from seven and11 year-old Karenean girls, who had no previous history of surgery, blood transfusion,intravenous medication, vaccination and dental therapy. These results suggest that HIVinfections have not yet reached to the hill tribes, except the Lahu-Na. One of the pos-sible transmission routes of HCV infection is a vertical or intrahhousehold infectionamong the hill tribes in northern Thailand.Key words: HIV, HBV, HCV, Hill Tribes, Northern ThailandINTRODUCTIONThe population of anti-HIV seropositive individuals is increasing in northern Thailand(Nopkeson et al., 1993; Nelson et al･, 1994)). It is also well known that there is a highprevalenve of other bio｡d-borne virus infections such as HBV and HCV among HIV positiveindividuals (Esteban et al., 1989; Sherman et al., 1991; Quan et al., 1991; Eysler et al., 1993;Received for publication, July 10,1996.Contribution No. 3336 from the Institute of Tropical Medicine, Nagasaki University.80Botti et弧1993; Bryan et aL, 1993; Yousukh et all, 1996)･ However, no seroepidemiologicalsurvey on HIV, HBV and HCV infections have been done among the hill tribes of northenThailand. The urban life in Thailand has changed almost out of recognition in the last twodecades, and lt is one of the main reasons for the rapid spreading of HIV infection (Wenigeret all, 1991; Nelson et al., 1994)･ However, the life style of the hill tribes that live in theremote and isolated mountain areas, settling in their own communities, have changed a little･The purpose of this study is to describe the prevalence and incidence of HIV, HBV and HCVinfections among the hill tribes of northern Thailand who are living in the semi-rural or ruralareas and compare lt with those living in the urban areas and also, to evaluate other risk■factors associated with HIV, HBV and HCV infections.MATERIALS AND METHODSÅ total of 114 serum samples were collected from the Karen, Mae Sam Lab, Maehongsorn province, 120 from the La-Wah, Mae La Noi, Maehong Sorn province and 76 from theLahu-Na Chiang Dao? Chiang Mai province in northern Thailand between January andMarch, 1993 (Figure 1)I We have chosen the small villages of these hill tribes because of thefollowing reasons: the village of the Karen is located in a remote mountain area, close to theborder of Myanmar (Burma) and the inhabitants have few contacts with urban areas and theThai. Contrary to this situation, the village of the Lahu-Na is located in a semi-rural areaalong the road between Chaing Mai and Chiang Rai and the inhabitants have commercialcontacts with urban areas and the Thai, The village of the La-Wah shows an intermediateFigure l･ Location of villages of the hill tribes in Northern ThailandCHINAMYANMARMYAN M/収LAOST王MLAN DCAMBAD IA--///VIETNAM■⊂コchiang Dao *　　　ChianJ RalMae LaNoir^Mae Sam I』b�"Chiang Mai′m瓜LAN D81situation betweeen the Karen's and the Lahu-Na's, namely, it is located in a rural area andthe inhabitants have occasional contacts with the Thai. Relevant information concerning eachindividual, such as, age, sex, history of surgery, blood tran血sion, intravenous medication,vaccination, dental therapy and presence of tattoes were recorded as accurately as possible…Sera were stored at -20℃ until examination･ Sera were tested for the presence of anti-HIVantibody (anti-HIV) by using a Particle-Agglutination method (Serodia-HIV, Fujirebio lnc.,Tokyo, Japan), Hepatitis B surface antigen (HBs-Ag) was detected by Reversed PassiveHemagglutination method (Antihebscell, International Reagents Corp., Kobe, Japan) and anti-Hepatitis B surface antibody (anti-HBs) by Reverse Hemagglutination method (Seroclit-antiHBs, The Chemo-Sero-Therapeutic Research Institute, Kumamoto, Japan) and anti-Hepatitisc antibody (anti…HCV) by a second generation indirect ELISA method (HCV ELISA, Diag-nostic Biotechnology Ltd., Singapore)･ Statistical analysis was performed using chi-square test(pく0･05)RESULTSHIV infection;Anti-HIV positive individuals were found only in the Lahu-Na (2 cases; 2.6%) 26 and42 year-old males, respectively (Table 1). The latter case had a previous intravenous medi-ca…亡ion, but the former had no history of such medications･We found no individual with double infection of HIV and HBV or HIV and HCV.Table l･ Prevalence of HIV infection in the Lahu-Na by age and sexAge (years)0-1415-2425-3435-4445-5455-64≧65TotalTotal (n)　　Men [n (%)]　women [n {%)]15　　　　　　oI15(　0)14　　　　　oI3(　0)　　/ll(　0)23　　　　1Ill( 9･1)　　0/12(　0)7　　　　1Il(100.0)　　/6(　0)11　　　　o/3(　0)　　I (　o)5　　　　　o/2(　0)　　/3(　0)1　　　　　oll(　0)76　　　　　2/36( 5･6)　　o/40(　0)HBV infection:Table 2, 3 and 4 describe the age and sex prevalence of HBV infection among the hilltribes. The Karen showed the highest incidence of HBs-Ag positive (15 cases- 13･2%), fol-lowed by the Lahu-Na (2 cases; 2.6%) and the La-Wah (2 cases; 1.7%). Fourteen out of 19(73･7/iO HBs-Ag positive individuals belong to the under 14 year-old population. Although比eKaren sh-ed a higher HBs-Ag positivity among women compared to men (20…8% vs･ 7.6X), the two other tribes had no women positive cases. Anti-HBs positive cases甲ere evenly82distributed in every age groups of the three tribes and predominantly found among females inthe La-Wah (23･0% vs. 13.0%) and the Lahu-Na (10.0% vs. 5.6%), except the Karen (14･9% vs. 14.9%). Total HBV markers were found 27.2% in the Karen, 20.9% in the La-Wah and10.5% in the Lahu-Na｡ Fourteen out of 19 (73･7タ　HBs-Ag positive cases had previous in-travenous medication or vaccination.Table 2. Prevalence of HBV infection in the Karen by age and sexHBsAg-positive [n (%)]　　　HBsAb-positive [n (%)]Age (years) Total (n)　　Men Women Men .　Women0-1415二2425-3435-4445-5455-64Total68239752日m4I42 (9･ 5)　　7/26 (27･0)1/13 (7-7)　　IIO (30･0)o/4( 0)　　/5(　0)o14( 0)　　/3(　0)o/3( 0)　　O/2(　0)o/1( 0)　　Il(　0)7I42 ( 16.7)　/26 (15･4)oI13 (　0)　1/10 (10.0)1/ 4 ( 25･0)　1I 5 (20.0)1I4(25･0)　1/3(　0)o/ 3 (　0)　I 2 (50.0)1/1(100･0)　OIl(　0)5/67 (7…5)　10I47 (21.3)*　10I67 ( 14.9)　/47 (14･9)*p<o｡ o5 compared with men.Table 3･ Prevalence of HBV infection in the La-Wah by age and sexTotal (n)Age (years)0-1415-2425-3435-4445-5455-64≧65TotalHBsAg-positive [n (%)]　　　HBsAb-positive [n (%)]Men Women Men W omen39m2716Ill671201/19 ( 5.3)　　0/20 (oI4(　0)　　/10(1/ 5 (20.0)　　I22 0oI8(　0)　　I80oI5(　0)　　/6(oI3(　0)　　/3(oI2(　0)　　/5(2/46 ( 4.3)　　I74 (o)　　2I19 (10･5)　1I20 ( 5･0)o)　1/ 4 (25-0)　/10 (30･0)o)　1/ 5 (20…0)　　6/22 (27･3)o)　　2/ 8(25.0)　/ 8　37.5o)　oI5( 0)　I6(50.0)o)　oI3( 0)　I3( 0)o)　oI2( 0)　I5(20･0)o)　　6/46 (13･0)　17I74 (23.0)Table 4･ Prevalence of HBV infection in the Lahu-Na by age and sexHBsAg-positive [n (%)]　　　HBsAb-positive [n (%)]Age (years) Total (n)　Men Women Men Women0-14　　　　1515-24　　　　1425-34　　　　2335-4445…54　　　　1155-64　　　　　5176≧65Total2I15 (13…3)o/3(　0)　　/ll(　0o/ll(　0)　　/12(　0)o/1(　0)　/6( 0)oノ3(　0)　　ノ　( 0)oI2(　0)　I3(　0)O∫l(　02I36( 5･6)　　OI40( 0)0/15(　0)0/3(　0)2/ll (18-2)0/1(　0)OI3(　0)0/2(　0)0/1(　0)2/36 ( 5…6)1Ill ( 9.11/12 ( 8.3)1I 6 (16.7)0/ (　0)1/ 3 (33.3)4I40 (10.0)83HCV infection;Table 5, 6 and 7 show the age and sex prevalence of HCV infect!｡n among the hilltribes. The La-Wah had the highest incidence of anti-HCV positivity (4 cases; 3.3%), followedby the Karen and the Lahu-Na (3 and 2 cases each; 2.6%, respectively)･ The two anti-HCVpositive individuals were a seven and an ll year-old girl from the Karen, who had noprevious history of surgery, blood transfusion, intravenous medication, vaccination and dental､,therapy. The La-Wah showed a higher anti-HCV positivity among men compared to women(6.5% vs. 1･4%), however, the opposite was found in the Karen and the Lahu-Na (1.5% vs.Table 5,, Prevalence of HCV infection in the Karen by age and sexAge (years)0-1415-2425-3435-4445-5455-64TotalTotal (n)　　　Men 【n lK)】　　Women 【n (%)]68239752IE0/42 (　0)　　　　/26 (7.7)OI13(　0)　　　　IIO( 0)0/4(　0)　　　　I5( 0)0/4(　0　　　　　/3( 0)1I3(33.3)　　　　/2( 0)0/1(　0)　　　　Il( 0)1I67 ( 1.5)　　　　/47 (4…3)Table 6･ Prevalence of HCV infection in the La-Wah by age and sexAge (years)0-1415-2425-3435-4445-5455-64≧65TotalTotal (n) Men [n (%)]　　Women 【n (K)l391427Iffll671200/19(　0)　　　　/20( 0)1/4(25.0)　　　　IIO( 0)0/5(　0)　　　　/22(4.5)1I8(12.5)　　　　/8( 0)1/5(20･0)　　　　OI6( 0)0/3(　0)　　　/3( 0)0/2(　0)　　　　I5( 0)3ノ46 ( 6.5)　　　　I74 (1.4)Table 7. Prevalence of HCV infection in the Lahu-Na by age and sexAge (years)0-1415-2425-3435-4445-5455-64≧65TotalTotal (n) Men 【n (%)]　　Women 【n (K)l1514237ll51760/15(　0)OI3　　0)　　　/ll(　0)OIll( 0)　　　/12( 0)0/1( 0)　　　I6(　0)OI3( 0)　　　/8(15.0)0/2( 0)　　　/3(　0)0/1(　0)0/35( 0)　　　/41 (4.9)844.3X O% vs･ 4･9%, respectively)I Four out of nine anti-HCV positive cases (44.4%) hadprevious Intravenous medication, and one case had a history of blood transfusion.DISCUSSIONThe urban life of Thailand has completely changed in the past two dacades, and thiscould be one of the reasons why HIV infections is spreading so rapidly (Weniger et alリ1991; Nuchprayoon and Chumnijarakij, 1992). The prevalence of HIV infection in semi-ruralareas ｡f the Thai ln Chiang Mai province was 4.6% (Nelson et al., 1994)･ Yousukh et al.(1996) reported that other blood-borne virus infections, especially, HCV infection is increasingin number accompanied with the spreading of HIV infection in Chiang Mai area. Themountainous border between Thailand and Myanmar (Burma) is home to several ethnicgroups designated as the hill tribes. While their villages are scattered and located in remoteand isolated areas, nearly all of them are dominated by a single ethnic group. We have done=a seroepldemiological survey of HIV, HBV and HCV infections among the three hill tribeswho are living in the rural or semi-rural areas to know the prevalence and incidence of theseblood-borne virus infections among them.Ⅰn our study, two out of 310 (0.6%) individuals were found to be anti-HIV positive.Although HIV infection is still uncommon to the hill tribes than in urban areas, both identi-fled cases were from the Lahu-Na. whose village is located in a semi-rural area along the roadbetween Chiang Mai and Chiang Rai, provincial capitals of Chiang Mai and Chiang Rai pro-vines, respectively, and they have a close and commercial contact with the urban areas andthe Thai. This suggests that HIV infection can spread into the hill tribes together with theprogress of cultural and commercial exchange with the urban areas (Nopkeson, et al., 1992;Nelson et ai 1993; Nelson et al., 1994).ÅIthough the incidence of HBs…Ag positivity (13.2%) In the Karen was relatively higherthan in Chiang Mai area (Yousukh et al｡, 1996), the Lahu-Na and the La-Wah showed lowerincidence (2｡6 and 1.7%, respectively). These findings are not easy to explain. Further studieswill be needed to determine the usefulness of these findings. The incidence of HBs-Agpositive cases in these three hill tribes was highest among age groups between 0 and 24 yearsand suggests that vertical infections from HBs-Ag positive mothers and household contactsare the main transmission routes of HBV infection (Punyagupta et al, 1972; Pramoolsmsap eta且. 1986; Nuchprayoon and Chumnijarakij, 1992)…Nine out of 310 (2.9%) individuals showed anti-HCV positive and this incidence ishigher than Chiang Mai area (Yousukh et al., 1996). Four out of nine (44.4%) anti-HCVpositive individuals had previous intravenous medications and one case had previouslyreceived a blood transfusion. Two out of nine (22.2%) anti-HCV positive individuals werefrom昏even and ll year-old Karenean girls, who had no previous history of surgery, bloodtransfusion, intravenous medication, vaccination, dental therapy and tattoes. This result sug-gests that one possible transmission route of HCV infection is a vertical or intra-householdllnfect呈on｡85In conclusion, the incidence of HIV infection is low among the hill tribes compared tothe residents in urban and semi-rural areas. However, this can spread to remote mountainareas due to cultural and commercial interaction with urban areas･ A vertical or mtra-house-hold mode of infection can play one of the transmission of HCV infection among the hilltribes in northern Thailand.AcKNOWLED GEMENTSThis work was partly supported by a grant from the Ministry of Education, Science,Sports and Culture, Japan.REFERENCES1 ) Botti, P., Pistelli, A., Ganbassi, F…, Zorn, A. MリCaremelli. L., Peruzzi, SリSmorlesi, C., Masini, E…& Mannaioni, P. F･ (1992): HBV and HCV infection in i… v. drug addicts; coinfection with HIV. Arch.Virol. Supple･, 4, 329一-332･2) Bryan, J. PリSjogren, M. HリMalone, J. L., Macarthy, P･, Kao, T･ CリWagner, K., Sheffield, J.,Smith, E. & Ferine, P. L. (1993): Recombinant lmmunoblot assays for hepatitis C in human im-munodeflciency virus 1:ype-1 injected US Navy personnel･ J. Infect. Disease, March, 167 (3), 715-716.3 ) Esteban, J. I･, Esteban, R., Viladomiu, LリLopez-Talavera, J. CリHernandez･, J. M., Raget, M.,Vargas. V･, Gienesea, JリButti, M., Guardia, JリHoughton, M., Choo, Q. L･ & Kao, G. (1989):Hepatitis C antibodies among risk groups in Spain. Lancet, 2, 294-297.4) Eysler, M. E., Diamondson, L. S., Lien, J. M., Ehmann, W. C･, Quan, S. & Goedert, J. J. (1993):Natural history of hepatitis C virus infection in multitransfused hemophiliacs; effect of coinfectionwith human immunod-sficiency virus･ The multicenter Hemophilia Cohort Study. J･ AIDS. 6 (6),602-610.5) Nelson, K. E･, Celentano, D. D., Suprasert, S…, Wright, N･ Eiumtrakul, EリTulvatana, S.,Matanadarawoot. A･, Akarasewi, P., Kuntolbutra, S., Romyen, S., Sirisopana, N･ & Theetranont, C.(1993): Risk factors for HIV infection Among Young Adult Men in Northern Thailand. JAMA, 270 (8),955-960.6 ) Nelson, K. E., Suriyanon, V., Taylor, E., Wongchak, T., Kingkeow, C., Srirak, N., Lertsrimongkol,T= Cheewawat, W･ & Celentano, D･ (1994): The incidence of HIV-1 infections in village populationof northern Thailand. AIDS. 8 (7), 951-955.7 ) Nopkeson, T., Mastro, T. D., Sangkharomya, S., Sweat, M., Singharaj, P., Limpakarnjanarat, K.,Gayler, H. D. & Weniger, B. G. (1993): HIV-1 infection in young men in northern Thailand. AIDS,7, 1233-1239.8 ) Nuchprayoon, T. & Chumnijarakij, T. (1992): Risk factors for hepatitis B carrier status among blooddonors of the National Blood Center, Thai Red Cross Society. Southeast Asian J. Trop. Med. Pub.Hlth. 23 (2), 246-253.9 ) Pramoolsinsap, C-, Pukrittayakamee, S. & Desakorn, V. (1986): Hepatitis problem in Thailand.Southeast Asian T. Tr叩. Med. Pub. Hlth. 17 (2), 218-228.10) Punyagupta, SリOlson, L･ CリHarinasuta, U., Akarawong, K. & Varawidhya, W. (1973): Theepidemiology of hepatilヒis B antigen in a high prevalence area･ Am. J, Epidemiol. 97, 349-354.86II) Quan, C. MリKrajden, M., Grigoriew, G. A. & Salit, J. E. (1993): Hepatitis C virus infection inpatients infected with the human immunodeficiency virus. Clin. Infect. Dis. 17 (1), 117-119.12) Sherman,旺. E･. Freeman. S…　Harrison, S. & Andron, L. (1991): Prevalence of antibody to hepatitisC virus in patients infected with human immunodeficiency virus (letter)… J･ Infect･ Dis. 163, 414-415.13) Yousukh, A., Toriyama, K., Jutavijittum, P., Jiviriyawat, Y., Mundee, Y., Phornphutkul, K., Kusuda,M. & Itakura, H･ (1996): A high prevalence of hepatitis C virus infection among the human im…munodeficiency virus seropositive blood donors in Chiang Mai, Thailand. Trop. Med. 38 (1), 21-25.14) ｢Weniger, B･G･, Limpakarnjanarat, K., Ungchusak, K., Thanprasertsuk, K., Choopanya, K.,Vamchsem, S., Uneklabh, T., Thongcharoen, P. & Wasi, C. (1991): The epidemiology of HIV in-fecti｡n and AIDS In Thailand. AIDS, 5 (suppl. 2), S71-S85.

Seroepidemiological Survey of Human Immunodeficiency Virus (HIV), Hepatitis B Virus (HBV) and Hepatitis C Virus (HCV) Infections among The Hill Tribes in Northern Thailand

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Seroepidemiological Survey of Human Immunodeficiency Virus (HIV), Hepatitis B Virus (HBV) and Hepatitis C Virus (HCV) Infections among The Hill Tribes in Northern Thailand

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