Journal of the American Mosquito Control Association, 12(3):494_496,1996 Copyright O 1996 by the American Mosquito Control Association,Inc.

RELATIONSHIP BETWEEN BRETEAU AND HOUSE INDICES AND CASES OF DENGUE/DENGUE HEMORRHAGIC FEVER IN ,

SALLEHUDIN SULAIMAN, I ZAINOL ARIFIN PAWANCHEE,' ZULKIFLI ARIFIN, nNo AHMAD WAHAB,

ABSTRACT, The relationship between the Breteau index, the House index, and the occurrence of dengue/dengue hemorrhagic fever in the 6 zones of Kuala Lumpur was studied tbroughout 1994. Cases of dengue/dengue hemorrhagic fever varied between zones and between months, ranging from 0 to 2l cases. In most of the zones in Kuala Lumpur, the occurrence of dengue/dengue hemorrhagic fever has no relationship with the Breteau and House indices. Cases of dengue/dengue hemorrhagic fever occurred in all zones despite the low Breteau and House indices.

In Southeast Asia, Aedes albopictus (Skuse) Lumpur whereby the municipality was divided has been incriminated as a secondary vector of into 6 zones with a population of about 1.2 mil- dengue and Aedes aegypti (Linn.) as the princi- lion. The rainfall in Kuala Lumpur for the year pal vector of dengue viruses (Gould et al. 1968, 1994 was between 127.9 and 426.5 mm and the Russell et al. 1969, Chan et al. l97lb, Jumali et mean monthly temperature was between 24.2 al. 1979, Harinasuta 1984). The dengue viruses and 25.1'C. The 6 zones were named City Cen- may produce occasional fatal cases, usually ter, Damansara, , , Ceras, and Ja- among children (Rudnick and Chan 1965, Har- lan Lama, respectively. A total of 43,277 inasuta 1984). Macdonald (1956) conducted ex- premises comprising houses, flats, shops, restau- tensive studies on the distribution and dispersal rants, factories, markets, construction sites, and of Ae. aegypti in Malaya. According to Chan et workshops were inspected in City Center, al. (1971a) the most common breeding habitats 17,345 premises at Damansara,34,673 premises of Ae. aegypli were ant traps, earthenware jars, at Kepong, 29,636 premises at Setapak, 42,835 bowls, tanks, tin cans, and drums, with ant traps premises at Ceras, and 22,364 premises at Jalan being the most common indoors and earthen- Klang Lama, respectively. A staff of 90 was in- ware jars the most common outdoors. Breeding volved in carrying out the survey throughout the habitats for Ae. albopictus were commonly year. The Ae. aegypti and Ae. albopictus iden- earthenware jars, tin cans, ant traps, rubber tires, tified were pooled as Aedes spp. and the Breteau bowls, and drlrms; ant traps were the most com- index (number of positive containers per l0O mon indoor habitat and tin cans were the most houses) and House index (percentage of houses conrmon outdoors. The majority of Ae. aegypti or premises infested with Aedes larvae/pupae) breeding habitats were found indoors, whereas were determined. only half of all the Ae. albopictus breeding hab- All cases of confirmed dengue/dengue hem- (1991), itats were indoors. Sulaiman et al. in orrhagic fever from all hospitals, viz., the Uni- their study on distribution and abundance of Ae. versity of Malaya teaching Hospital, Kuala aegypti and Ae. albopictus in an endemic area Lumpur Hospital, Sentosa Medical Center, Pan- of dengue/dengue hemorrhagic fever in Kuala tai Medical Center, and Institute of Medical Re- indicated Ae. Lumpur, that albopictus apparently search were reported to the Department of was to Ae. aegypti mos- dominant as a domestic Health, Kuala Lumpur municipality. The sero- quito species inside premises of houses, shops, logical test performed was the hemagglutination and factories. inhibition test of Clarke and Casals (1958). Pos- The objective of our study was to find the itive cases were to be followed by chemical in- relationship between the Breteau and House in- tervention by fogging using cyfluthrin. The cor- dices and cases of dengue/dengue hemorrhagic relation coefflcient of the relationship between fever in Kuala Lumpur, Malaysia. the Breteau index, the House index, and cases An extensive study was conducted in Kuala of dengue/dengue hemorrhagic fever was ana- lyzed according to Meddis (1975). ' Department of Parasitology and Medical Entomol- The cases of dengue/dengue hemorrhagic fe- ogy, Faculty of Medicine, Universiti Kebangsaan Ma- ver varied between zones and months, ranging laysia, Jalan Raja Muda Abdul Aziz, 50300 Kuala from O to 2l cases monthly (Table 1). The Se- Lumpur, Malaysia. 2 Vector Control Unit, Department of Health, Kuala tapak zone had the highest number of reported Lumpur Municipality, KM 4 Jalan Ceras, 56100 Kuala dengue/dengue hemorrhagic fever cases (ll7) Lumpur, Malaysia. durins 1994. The Damansara zone had the low-

494 Sep,rgraern1996 OprnettoNeL ,lNo Scrrvnnc Norps 495

Table 1. The monthly Breteau and House indices of Aedes spp. and reported dengue/dengue hemorrhagic fever casesin 6 zones of Kuala Lumpur city in 1994. Jalan Klang City Center Damansara Kepong Setapak Ceras Lama HI' DF/ HI DF/ HI DF/ HI DF/ HI DF/ HI DF/ Month (Vo) BPDIJF (Vo) BI DHF (7o) BI DHF (Vo) BI DHF (Vo) BI DHF (7o) BI DHF Jan. 4.7 7 9 5.7 6 61.82 8 3.2 5 81.32t3 1.5 2 4 Feb. 4.9 7 8 5.2 5 8 2.73 0 3.84 8 2.33 9 t.4 2 6 March 3.2 4 | 2.1 2 5 2.63 5 0.9 1 81.72l1 0.1 I 6 April 4.9 7 9 2.2 3 4 2.O3 7 2.63 9 3.04 6 1.5 2l5 May 3.9 5 7 2.7 3 l 2.8 5 3 3.64 t0 2.4 3 ) l.l 2 June 3.7 5 6 3.0 7 01.52 o 2.33 41.62 f 0.8 3 July 3.6 4 9 4.8 5 3 r.42 | 2.83 31.42 6 0.5 J Aug. 3.2 4 7 6.5 7 6 2.1 3 3 1.5 2 t2 0.9 I 1.2 9 Sept. 3.7 4 5 3.8 lo 21.72 2 2.O2 8 1.3 2 6 0.5 8 Oct. 4.6 7 I t-5 ll o 2.7 4 | 2.64 19 0.9 r 3 1.1 Nov. 4.5 7 ll 4.4 5 I 4.5 5 8 3.44 21 2.7 3 3 2.3 2 8 Dec. 4.5 6 7 7.2 7 6 r.72 7 1.4 I 71.52 6 3.3 3 I Totals 86 42 45 tt7 80 68 rHI = Houseindex. 'BI = Breteauindex. r DF/DI{F : Denguefever md denguehemonhagic fever- est number of cases (42). The difference could cases had no relationship with either the House be because the Setapak zone contained more index or the Breteau index. slum areas with poor and improper sanitation, In Singapore, the Aedes House index has been whereas the Damansara zone was highly devel- reduced to 2Vo since 1983, but in spite of this 3 oped with good sanitation facilities. According epidemics of dengue/dengue hemorrhagic fever to Gubler (1989), one factor that has contributed have occurred-in 1986. 1987. and 1989. In to the failure of most Latin American countries 1989, stepped up control measures were under- to control Aedes aegypti during recent years has taken and 390,345 premises were checked; been the increasing production of solid waste 5,043 or l.3%o were found to be positive for Ae- coupled with inadequate refuse collection ser- des aegypti (World Health Organization l99O). vices. Studies in Singapore in l99l indicated that den- The correlation coefficient (r) of the relation- gue fever/dengue hemorrhagic fever was signif- ship between the Breteau index and den- icantly correlated with the Aedes House index. gue/dengue hemorrhagic fever cases in each Major habitats were ornamental and domestic month was not significant in the zones of Jalan containers (Anonymous 1992). Thus, our finding Klang Lama (r : O.O2,P > O.O5),Ceras (r = contradicted the studies in Singapore. -0.04, P > 0.05), Setapak(r: O.32,P > 0.05), Ho and Vythilingam (1980), in their survey Kepong (r : 0.13, P > 0.05), and Damansara of Ae. aegypti in , peninsular Malaysia, -O.29, (r = P > 0.05). However, in the City indicated that the most common indoor larval Center zone the correlation coefficient was sig- habitat in urban areas is the bathroom tank. In nificant at the 5Vo level (r : 0.60, P < 0.05). both urban and rural areas, the outdoor prefer- Similarly, the correlation coefficient of the re- ence is for earthenware jars. Lee and Cheong lationship between the House index and den- (1987), in a preliminary Ae. aegypti larval sur- gue/dengue hemorrhagic fever cases in each vey in the suburbs of Kuala Lumpur city, found month was not significant in the zones of Jalan that the premise and Breteau indices of 3 local- -0.09, Klang Lama (r : P > 0.05), Ceras (r : ities in the study area exceeded the 5Vo and 20 -0.15, P > 0.05), Setapak(r: O.21,P > 0.05), level, respectively, indicating that these locali- = Kepong (r O.29, P > 0.05), and Damansara ties were at risk of dengue outbreak. Both Ae. : (r O.24, P > 0.05), However, in the City Cen- aegypti a;ld Ae. albopictus were found breeding ter zone the correlation coefficient was signifi- indoors and outdoors in a number of containers cant at the 2.5Vo level (r = 0.61, P < 0.025). used for water storage. Thus, in most of the zones in Kuala Lumpur, the According to Tonn et al. (1969) there was ev- occurrence of dengue/dengue hemorrhagic fever idence of slight changes in the number of oc- 496 JounNer-op rsp Aurmcel Mosqurro Corrnol AssocnrroN Vol. 12,No.3

cupied habitats from time to time, the chief in- with arthropod-borne viruses. Am. J. Trop. Med. crease being between the cool and the warm sea- Hyg.7:561-573. sons and the chief decrease from the wet to the Gould, D. J., T, M. Yuill, M. A. Moussa, P Simasa- cool season. However, it seems unlikely that out- thien and L. C. Rutledge. 1968. An insular outbreak of dengue haemorrhagic fever breaks of dengue hemorrhagic fever can be ex- III. Identification of vectors and observations on vector ecology. Am. J. plained by increases inAe. aegypti densities dur- Tiop. Med. Hyg. 17:6O9-618. ing the wet season. Tonn (1970), et al. in their Gubler, D. G. 1989. Aedes aegypti and Aedes albo- study on magnitude of seasonal changes in lar- pictus borne disease control in the 1990s: top down val populations ofAe. aegypti in Bangkok, Thai- or bottom up. Am. J. Tlop. Med. Hyg. 4O:571-578. land, concluded that there was some reduction Harinasuta, C. 1984. Mosquito-borne diseases in in the larval population during the cool and hot Southeast Asia. Mosq.-Borne Dis. Bull. 1:1-l I . seasons and that the magnitude and timing of the Ho, T M and I. Vythilingam. 1980. A preliminary decrease varied from place to place. The reduc- strvey of Aedes aegypti in Selangor, peninsular Ma- laysia. Med. J. Malays. 34.4@-414. tion was of the order of ll-26Vo. Local envi- Jumali, Sunarto, D. J. Gubler, S. Nalim, S. Eram and ronmental changes, as well as climatic changes, J. S. Saroso. 1979. Epidemic dengue haemorrhagic greatly influenced the Ae. aegypti population. fever in rural Indonesia III. Entomological studies. Gould et al. (1968), in their entomologic studies Am. J. Tfop. Med. Hyg. 28:717-724. on Koh Samui Island in Thailand. found that Ae. l-ee, H. L. and W. H. Cheong. 1987. A preliminary aegypti and Ae. albopictus appeared to coexist. Aedes aegypti larval survey in the suburbs of Kuala Southwood et al. (1972), in their studies on the Lumpur city. Tiop. Biomed. 4: I I l-l 18. life budget of Ae. aegypri in Wat Samphaya, Macdonald, W. W. 1956. Aedes aegypti in Malaya I. Bangkok, Thailand, stated that there was no Distribution and dispersal. Ann. Trop. Med. Parasi- tol. 50:385-398. clear trend of association between mortality and Meddis, R. 1975. Statistical handbook for nonstatis- for season except a decrease in larval mortality ticians. McGraw Hill Book Company (UK) Ltd. in April-May preceding the increase in annual Maidenhead, Berkshire, England. incidence of hemorrhagic fever, which usually Rudnick, A. and Y. C. Chan. 1965. Dengue type 2 occrrs in June. virus in naturally infected Aedes albopictus mos- To conclude, the present study indicated that quitoes in Singapore. Science 149:638-639. cases of dengue/dengue hemorrhagic fever oc- Russell, P K., D. J. Gould, T, M. Yuill, A. Nisalak and curred in all zones of Kuala Lumpur despite the P E. Winter. 1969. Recovery of dengue--4 viruses patients low Breteau and House indices. from mosquito vectors and during an epi- demic of dengue haemorrhagic fever. Am. J. Thop. We thank the Universiti Kebangsaan Malaysia Med. Hyg. 18:58O-583. and Vector Control Unit, Municipality of Kuala Southwood, T R. E., G. Murdie, M. Yasuno, R. J. Tonn Lumpur, for providing research facilities. We ap- and P M. Reader. 1972. Studies on the life budget preciate the financial support of the Ministry of of Aedes aegypti in Wat Samphaya, Bangkok, Thai- Science Technology and Environment Malaysia land. Bull. W.H.O. 46:2ll-226. for providing research grant IRPA 3-07-03-095. Sulaiman, S., Z. A. Pawanchee, J. Jeffery, I. Ghauth We are grateful to Wirda Hassan for typing the and V. Busparani. 1991. Studies on the distribution manuscript. and abundance of Aedes aegypti (L.) and Aedes al- bopictus (Skuse) (Diptera: Culicidae) in an endemic area of dengue/dengue haemorrhagic fever in Kuala REFERENCES CITED Lumpur. Mosq.-Borne. Dis. Bull. 8:35-39. Anonymous. 1992. DFTDHF surveillance-Singa- Tonn, R. J., W. W. Macdonald, P M. Sheppard and S. pore, 1991. Virus Info. ExchangeNewslet. 9: l0-l 1. Jatanasen. 1970. The magnitude of seasonal Chan, K. L., B- C. Ho and Y. C. Chan. l97la. Aedes changes in larval populations of Aedes aegypti in aegypti (L.) and Aedes albopiazs (Skuse) in Sin- Bangkok, Thailand. Bull. W.H.O. 42:943-95O. gapore City 2. Larval habitats. Bull. W.H.O. 44: Tonn, R. J., P M. Sheppard, W. W. Macdonald and Y. 629-633. H. Bang. 1969. Replicate surveys of larval habitats Chan, Y. C., B. C. Ho and K. L. Chan. l97lb. Aedes of Aedes oegypti in relation to dengue haemorrhagic aegypti (L.) and Aedes albopictzs (Skuse) in Sin- fever in Bangkok, Thailand. Bull. W.H.O. 4O:819- gapore City 5. Observations in relation to dengue 829. haemorrhagicfever. Bull. WH.O. 44:651-658. World Health Organization. 1990. Epidemiology of Clarke, D. H. andJ. Casals. 1958. Techniquesforhae- dengue fever/dengue haemorrhagic fever-Singa- magglutination and haemagglutination-inhibition pore. WkIy. Epidemiol- Rec. 14:1O4-1O6.