Short Note -3
Status Report on DF/DHF During 1998 in the National Capital Territory of Delhi, India R.S. Sharma , N. Panigrahi , S.M. Kaul , Shivlal 1 and Barua K# and M. Bhardwaj# * #
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By
National Anti-Malaria Programme, 22 Sham Nath Marg, Delhi –110 054
National Institute of Communicable Diseases, 22 Shamnath Marg, Delhi-110 54
The National Capital Territory (NCT) of Delhi, the Capital of the Republic of India, is situated on the banks of the river Yamuna. It covers an area of 1485 sq km, of which 900 sq km is urban and the rest is classified under the rural category. The city has experienced a phenomenal growth in its population, and as a centre offering vast economic opportunities has been attracting migrants not only from its immediate neighbourhood but also from far off places. The population of Delhi is now estimated to be much above 10 million. Delhi has been endemic for dengue, and the first DHF outbreak was reported in 1988 with 33% mortality among children admitted into hospitals(1). The last outbreak of DHF occurred in the NCT of Delhi in 1996 when more than 10 000 cases and 450 deaths were recorded(2). Comprehensive studies on the prevalence of Aedes aegypti, the vector responsible for DF/DHF, carried out in Delhi Dengue Bulletin – Vol 23, 1999
revealed a high breeding potential of the species. While the species is present all the year round, but the seasonal peak coincides with the rainy season from July to October(3,4). After the 1996 outbreak, dengue was declared a dangerous disease under the Delhi Municipal Act, which enjoins upon all medical practitioners/hospitals and other persons to provide information to the Municipal Health Officer and the National Anti-Malaria Programme (NAMP) which is the nodal agency for the monitoring of dengue at the national level. The present communication contains the disease incidence as reported by all the hospitals of the city and the entomological indices collected by NAMP.
Dengue incidence The blood samples of clinical dengue cases were confirmed in different hospitals by 109
Status report on DF/DHF during 1998 in the National Capital Territory of Delhi, India
using the Pan-Bio, Australia, test kit for IgM antibodies. The dengue cases were also diagnosed at the National Institute of Communicable Diseases by using antigens from the National Institute of Virology, Pune. During 1998, a total of 518 cases were reported, out of which 332 cases (64%) were found to be positive for dengue. The monthwise incidence of dengue cases and deaths are shown in Fig.1. The age-wise and sexwise incidence of dengue cases is given in Fig.2. It is apparent that the occurrence of the cases started with the onset of the rainy
season (July) and peaked in November. Nearly 69.5% of the cases were in the agegroup of 14 and above. In all age-groups males outnumbered the females. Longitudinal vector surveillance studies undertaken by the NAMP in all divisions of the city, namely, Delhi Municipal Corporation area, New Delhi Municipal Committee area and the Defence area, showed heavy breeding of Aedes aegypti in all the areas. The monthly cumulative container indices fully synchronized with the disease incidence (Fig.3).
Figure 1. Monthwise DF/DHF cases during 1998 in NCT Delhi 350 300 250 200 150 100 50 0 Reported Confirmed Deaths Jan 3 0 0 Feb 0 0 0 Mar 0 0 0 Apr 2 0 0 May 0 0 0 Jun 0 0 0 Jul 4 2 0 Aug 13 6 0 Sep 29 19 0 Oct 167 79 3 Nov 287 203 2 Dec 33 23 0
Reported
Confirmed
Deaths
Fig 1
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Status report on DF/DHF during 1998 in the National Capital Territory of Delhi, India
Figure 2. Age and sexwise distribution of DF/DHF cases in NCT Delhi during 1998 180 160 140 120 100 80 60 40 20 0 MALE FEMALE
0-1 2 3
1-4 11 8
4-9 27 17
9-14 20 14
>14 162 69
MALE
FEMALE
Fig.2
Figure 3. Seasonal fluctuations of breeding infestation of Aedes Aegypti during 1998 in NCT Delhi
1400 No. of Aedes breeding sites 1200 1000 800 600 400 200 0 82 71 81 28 33 51 93 691 678 1121 1147
341
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT NOV DEC
Months
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Status report on DF/DHF during 1998 in the National Capital Territory of Delhi, India
Therefore, it may be concluded that for effective control of DF/DHF in NCT, Delhi, there is a need for building-up a comprehensive vector control programme based on source reduction, and by elimination of all types of breeding sites of the vector species under domestic and peridomestic situations, through community participation supported by comprehensive legislative measures. References 1. Kabra SM, Verma IC, Arora NK, Jain Y and Kalra V (1992). DHF in children in Delhi. Bull. WHO. 45:105-108.
2. Kaul SM, Sharma RS, Sharma SN, Panigrahi N, Phukan PK and Shiv Lal (1998). Preventing dengue and DHF. The role of entomological surveillance, Jour. Com. Dis. 30:187-192. 3. Krishna Murthy BS, Kalra NL, Joshi GC and Singh MM (1965). Reconaissance survey of Aedes mosquitoes in Delhi. Bull. Ind. Soc. Mal. Com. Dis. 2:56-67. 4. Katyal R, Singh K and Kaushal Kumar (1996). Seasonal variations in Aedes aegypti population in Delhi.
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