Entomological and Epidemiological Interpretations for Dengue Situation in Data Ganj Buksh Town, Lahore, Pakistan

Arooj Aftab Nadeem<sup>1,2</sup>; Farkhanda Manzoor<sup>1,2</sup>

Research Report

Entomological and Epidemiological Interpretations for Dengue Situation in Data Ganj Buksh Town, Lahore, Pakistan

Arooj Aftab Nadeem^1,2

, Farkhanda Manzoor^1,2

1. Provincial Medical Entomologist, Directorate General Health Services Punjab, Lahore, Pakistan
2. Department of Zoology, Lahore College For Women University, Lahore, Pakistan

Author

Correspondence author
Journal of Mosquito Research, 2016, Vol. 6, No. 4 doi: 10.5376/jmr.2016.06.0004
Received: 28 Sep., 2015 Accepted: 10 Dec., 2015 Published: 19 Jan., 2016

This is an open access article published under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Preferred citation for this article:

Nadeem A.A., and Manzoor F., 2016, Entomological and Epidemiological Interpretations for Dengue Situation in Data Ganj Buksh Town, Lahore, Pakistan, Journal of Mosquito Research, 6(4): 1-6 (doi: 10.5376/jmr.2016.06.0004)

Abstract

Lahore is one of the dengue endemic cities of Pakistan. Very few studies have been published on entomological and epidemiological aspects of dengue in Lahore: Pakistan. Area specific knowledge on breeding of mosquitoes, types of containers and seasonal rhythms of vector population is essential for preparing an effective prevention plan against dengue. During present study from January 2013-December 2013, Aedes larvae situation in 18 Union Councils of Data Ganj Buksh Town, Lahore, confirmed dengue patients UC wise breakup, type of containers from which larvae were found during surveillance in 2013 were discussed in detail. Results of study indicate that out of 18 UC’s six were most vulnerable for dengue larvae, 1,023 larvae from 613 sites were detected, 628 larvae were from indoor spots and 395 were from outdoor spots. 203 patients were reported in the town till December 2013. It was concluded that due to poor quality of spray and extensive fogging in the months of October and November incidence of larvae, adults and no of dengue patients increased in 2013.

Keywords

Lahore; Aedes; Larvae; Surveillance; Insecticide

1 Introduction

Dengue Fever, Dengue Shock Syndrome and Dengue Hemorrhagic Fever are major vector borne diseases after Malaria in Pakistan. Dengue fever is increasingly becoming an epidemic in Pakistan. In Pakistan dengue is emerging as one of the major public-health problem particularly since 2005 threatening the millions of people due to prevailing peculiar socio-economic conditions and epidemiological situation. Historically dengue has been endemic in the southern parts of country. In Pakistan first time dengue was recognized in 1994 in Karachi and 1 patient out of 145 was died. In October 1995, 57 out of 76 persons were found positive for antibodies against dengue virus in Hub, Southern Balochistan. In October 2003 dengue outbreaks were detected for the first time in sub-mountainous areas of district Haripur, Khyber Pakhtoonkhawa province and district Khushab, Punjab Province claiming 6 lives among 717 cases. In October 2005, Dengue again hit Karachi after 10 years and 21 deaths out of total 103 confirmed cases were recorded. In November 2011, it has killed over 300 people in the last several months and over 14,000 are infected by this mosquito-borne disease. Majority of the people infected are from the Lahore area in Punjab, Pakistan.This vector borne disease became a major threat to health of people especially of urban and semi urban areas of District Lahore, Sheikhupura, Gujranwala, Faisalabad, Rawalpindi and Multan. Aedes agypti and aedes albopictus are considered are major vectors for spreading of virus through infected mosquitoes and infected human blood.

Data Ganj Buksh Town is one of town of Lahore having estimated population of 2.1 million with total 18 Union Councils boundaries are attached with Samanabad town, Ravi Town and Gulberg Town. One of the most thickly populated town with high influx of people as trade hub. Thousands of junkyards, tyres market at Nilla Gumbad and Nolkha Market, Bilal Ganj. Old inaccessible multistoried buildings, abandoned and locked buildings, narrow streets, basements, small industrial units and cottage industries are such geographical and socio-economic factors which have made this town as the most vulnerable town for breeding sites of larvae of dengue vectors and dengue patients. Due to lack of human resources for indoor and outdoor surveillance and quality of surveys are other contributing factors for high larval incidence in the town. Various studies are available to understand the burden of dengue, which will also determine the representativeness of the surveillance data (Beatty, 2010; Arunachalam, 2010).

2 Materials and Method

Lahore (31˚ 32’59N; 74˚ 20’37 E), Punjab covers a total land area of 404 km², but the city is still growing at a considerable rate. The weather of Lahore is extreme during the months of May, June, and July when the temperatures soar to 45 – 50 ᵒC which is the hottest time of the year. Following the end of July the monsoon seasons starts with heavy rainfall throughout the city. December, January and February are the coldest months when temperatures can drop to −1 ᵒC. Data Ganj Buksh site is chosen for study as it is considered as the most vulnerable town with regard to potential sites and number of dengue cases. This is comparative study of larval density, adult mosquitoes, Dengue and Dengue Hemorrhagic with months as well as Union Councils climatic and environment changes comprising of one year (Jan. 2013-Dec. 2013). Town’s demography, topography and geography are most suitable for dengue causing vectors. Data Ganj Buksh Town is one of most thickly and populated town comprising of 21 lac population with 18 union councils which was convenient random sample. Data from dashboard of PITB taken which were uploaded by various health and other allied department field staff such as TMAs, Environment, local government, Education, fisheries, WASA and PHA. Dengue patients’ data and other diagnostic lab results of these patients were taken from teaching hospitals and private hospitals like Mayo Hospital, Services Hospital, Ganga Ram Hospital and General Hospital.

In study 139 Lady Health Workers/Lady Sanitary Patrols were given Indoor Surveillance performs and each LHWs/Lady Sanitary Patrol surveyed clusters of 500 houses monthly basis. Each team comprise of two members and in this way about 70 teams 35,000 houses were sweep up in one month and in one year 2,450,000. Each house surveyed 12 times in this cluster round the year. Similar exercise was conducted by Outdoor teams and conducted Outdoor Surveillance activities by 18 CDC Supervisors, 36 Sanitary Patrols and builders. The similar perform were given to these male field staff and total 27 teams in eighteen union councils conducted these surveys on specially designed performs containing information about dengue vectors and larvae. These teams checked daily 20 spots and 140 weekly and 560 spots weekly and total 6,720 spots round the year. Addresses with contact numbers were noted where larvae were found and mechanical and chemical measures were adopted after finding larvae or adults. Results were tabulated in graphs against dengue patients of these union councils and try to make a relationship with dengue patients, virus and vectors.

3 Statistical Analysis

All the data collected through performs, questionnaire, interviews, stock registers, hospitals, and focal persons of dengue of all allied departments engaged in anti dengue campaign, indoor and outdoor surveillance activities were entered in Microsoft Excel 2010. The tables were analyzed through Chi-Square Analysis (test for heterogeneity or independent using the statistic version 8.1 Analytical Software 2005.

4 Results and Discussion

Out of 18 Union Councils (UC’S) 5 to 6 UC’s (69, 70, 71, 72, 77, 78 &79) were the most vulnerable and high larval incidence was observed round the year by Indoor and Out Door Surveillance teams. At 613 spots/sites larvae were found at Indoor and at 379 spots/sites, larvae were identified outdoor. Table 1 indicates that from UC 69, 72, 78, maximum larval density was reported both indoor and outdoor and patients’ ratio was also high in these union councils. From UC 85, 53 indoor positive sites but only one dengue patient was reported. It may be due to reason that virus in the vectors is not circulating. The incidence of larvae may be ten times more which our naked eyes could not see due to its complex bionomic (Habitat), inaccessible areas, containers and top roofs of multistoried buildings. Early rain in the month of May and equal intervals of splash round the year is also contributing factor towards high density of larvae in the month of July, august, September and October and aedes adult vectors in the month of September, October and November. If we compare larval incidence of these UC’s to that of dengue patients they are directly proportional to larval situation whether detected indoor or outdoor. Khormi and Kumar’s study provides evidence that mosquito density is significantly associated with DF disease in Jeddah (Khormi et al., 2011).

Table 1 Showing larvae incidence in DGBT town, 2013

Table 2 shows that 201 confirmed dengue patients were reported in the town till 2^nd December 2013. From UC’s 68, 67, 69, 70, 71 72, 67, 79 more dengue cases were confirmed, suspected and patients were reported (Table 2). The reason may also be these union councils have very complex habitat. Area is either commercial, multistoried buildings, narrow old streets, inaccessible, basements, junkyards, high density of population, poor sewerage system and interrupted water supply or leaking water supplies the inhabitants of these areas are compelled to store water either on top of roof or on each storey. Water and electricity are connected problems. Load shedding compelled the people to store water in plastic containers usually having capacity of 100 gallons to 250 gallons and highest ratio of larval incidence were plastic containers of fixed type which are difficult to empty completely and wash or rub it completely. That is why after mechanical removal of larvae, again larvae found due to reason that they are fixed type with iron pipes, cannot rub completely to destroy eggs of vectors, they are in shabby or broken, presence of holes, or don’t have cover or lids. Lack of interest of residents or unawareness is also the major factor for presence of larvae again and again in the same containers. Drinking water tanks huge in size is difficult to eliminate larvae. Even temephos (Larvicide) cannot be sprinkled in water which can make drinking water unsafe for drinking. Plastic containers/ tanks on the roofs are good insulator of heat and cold that is why larvae are found even temperature drops below 10 degree centigrade. Aedes albopictut have adaptability factor and can survive even at lowest temperature of 0C. Larvae were found even in the months of November and December due to adaptation phenomenon and larvae prolong its life cycle for more than ten days and it was observed during trial in the fields. Most of times it happens that team took samples but not completely removed or emptied because of pressure from the inhabitants not to throw water or remove completely.

Table 2 Showing dengue patients UC wise break up

Regarding type of containers from which larvae were found, Table 3 indicates that from 225 sites larvae found during indoor surveillance and 117 sites were positive during outdoor surveillance activities. Air coolers, bird pots, tyre shops, stagnant water, flower pots, fridge trays and other junk materials were such potential sites where larvae were detected inside the houses and outside of the houses. Air coolers were second most potential sites of larvae due to reason that people don’t remove water or change water frequently. Even water remains stand when they are not in use especially in the month of July, September and October. That is why most of larvae found in these months were from air coolers. Their side walls which are made of KHAS act as good hiding sites for adults’ mosquitoes and to stick their eggs being moist, cold and humid. Previous research supports findings of our results that these containers act as breeding sites of mosquitoes especially when rain water is stored (Pham, 2011; Tran, 2010). Furthermore, it was also observed that despite cold weather of November and December Aedes albopictus were seen inside houses and most of larvae develop from air cooler’s stagnant water. It is also noteworthy that water pots for birds are the third most source or potential site of larvae inside houses as well as outside houses. On roof tops of residential and commercial buildings, in graveyards and darbars, dargahas etc. there are numerous bird pots. Although they were broken by surveillance teams but people put new one and do not change water regularly.

Table 3 Types of containers from which larvae were detected

Regarding impact of environmental factors, various studies have proved that the distribution of the vector varied remarkably with temperature, relative humidity and rainfall (Rowley and Graham, 1968; Khormi, 2011). It is also evident from Table 4 that during the month of January to April no larvae were detected indoor sites whereas at outdoor spots larval incidence was low up to month of April. But early rain in the month of May and at regular intervals till September, the larval incidence increase to manifolds. The larval incidence or detection rate was highest in the month of September, August and even in the month of November. There are many reasons for high density of larvae. Larviciding in the months of February, March, April and Mid were weak or poor.

Table 4 Month wise status of larvae in town

Table 5 shows month wise status of dengue patients. Out of 203 dengue confirmed dengue patients more than half of confirmed patients reported in the month of November due to reasons that Aedes mosquitoes entered inside houses as temperature of outside falls down to considerable extent. Due to poor quality of Indoor Residual Spray either due to under dose or overdose and poor quality of spray and lack of basic techniques by the spray man of sprays operation were major factors for rising number of dengue patients. It is also important to note that as per protocols of WHO, only 3-4 rooms can be residually sprayed, but 2.5% deltamethrine SC was used by Health Department in the months of March, April, May, July, August, September and October 2013 which was not recommended by WHO. No previous data of resistance is available with department for this insecticide. It has been observed that Deltamethrine 2.5 percent SC has only knock down effect and no residual effect as compared to Deltamethrine 5 percent which has residual effect for more than 45 days. No attention was given for use of ITNs (Insecticides Treated Nets) as major intervention. Health Department spends huge money on purchase of insecticides but did not purchase repellents. Similarly, extensive fogging was conducted in the month of October and November without noticing adults’ mosquitos’ density available or that was not needed to be done. No entomological advice was sought. In these vulnerable Union Councils extensive fogging conducted in these two months which may create resistance.

Table 5 Confirmed dengue patients UC& month wise break up

Out of total 208 confirmed dengue patients, 136 are male and 72 female, which reveals that most of patients are infected at outdoor sites. If we see percentage, 65% are males and 35% are females. 12 were Dengue Hemorrhagic Fever, 3 were Dengue Shock syndrome and 192 were Dengue Fever cases. There were 04 deaths in Data Ganj Buksh Town. On Clinical investigation, IgM 184 were positive and 05 were negative, on screening of IgG 112, were positive and 33 were negative. 37 were positive for NS1 and 56 were negative. 09 were positive on PCR test and 06 were negative. If we see percentage of dengue patients, 69% were suspected patients of dengue 21% were confirmed and 10% were probable dengue patients (Table 6).

Table 6 Confirmed dengue patients further break up

Three kinds of chemicals interventions were conducted in the town, Larviciding, Indoor Residual Spray and Fogging Spray Activities. In Data Ganj Buksh Town, Temephos 1% granules and Temephos 50 EC (Organophosphates) were used for Larvicial activities, Deltamethrine 5% Wet able powder and Deltamethrine 2.5 SC(Pyrethroids) for Indoor Residual Spray activities and Deltamethrine 1.5% EC used in fogging Figure 1 shows graphic distribution of different insecticides used in the UC’S. Since 2006, it has been observed that disease prevention is less important than disease management (Khormi et al., 2011).

Figure 1 Graphical presentation of UC wise distribution of insecticide

5 Conclusion

At the end we can conclude that there is triangle i.e. man, vector and virus, when triangle complete virus circulate. We have to live with them and also to avoid them. We cannot eliminate or eradicate mosquitoes, whenever in nature you disturb the nature will also disturb you. Similarly virus and vector contact then result are the dengue patients. This is fact of dengue epidemiology that this disease pattern is cyclic. It takes ten years or more to enter in area and takes twice or thrice time period to go away, if you adopt all IVMs. We have to change people living behavior and use of plastic and disposal items must be discouraged.

References

Arunachalam N., Tana S., Espino F., Kittayapong P., Abeyewickreme W., Wai K.T., Tyagi B.K., Kroeger A., Sommerfeld J., and Petzold M., 2010, Eco-bio-social determinants of dengue vector breeding: a multicountry study in urban and periurban Asia, Bull World Health Organ, 88: 173-84

http://dx.doi.org/10.2471/BLT.09.067892

Beatty M.E., Stone A., Fitzsimons D.W., Hanna J.N., Lam S.K., Sirenda V., Maria G., Guzman J.F., Mendez-Galvan S.B., Halstead G.W.L., Joel K., Richard M., and Harold S. M., 2010, Best practices in dengue surveillance: A report from the Asia-Pacific and Americas dengue prevention boards, PLoS Neglected Tropical Disease, 4: 890

http://dx.doi.org/10.1371/journal.pntd.0000890

Khormi H.M., and Kumar L., 2011, Modeling dengue fever risk based on socioeconomic parameters, nationality and age groups: GIS and remote sensing based case study, Science of the Total Environment, 409: 4713-4719

http://dx.doi.org/10.1016/j.scitotenv.2011.08.028

Khormi H.M., Kumar L., and Elzahrany R., 2011, Describing and analysing the association between meteorological variables and adult Aedes aegypti mosquitoes, Journal of Food, Agriculture and Environment, 9: 954-959

Khormi H.M., Kumar L., and Elzahrany R., 2011, Modeling spatio-temporal risk changes in the incidence of dengue fever in Saudi Arabia: a geographical information system case study, Geospatial Health, 6: 77-84

http://dx.doi.org/10.4081/gh.2011.159

Pham H.V., Doan H.T., Phan T.T., and Minh N.N., 2011, Ecological factors associated with dengue fever in a Central Highlands province, Vietnam, BMC Infectious Diseases Journal, 11: 1-6

Rowley W.A., and Graham C.L., 1968, The effect of temperature and relative humidity on the flight performance of female Aedes aegypti, Journal of Insect Physiology, 4: 1251-1257

http://dx.doi.org/10.1016/0022-1910(68)90018-8

Tran H.P., Adams J., Jeffery J.A.L., Nguyen Y.T., Vu N.S., Kutcher S.C., Kay B.H., and Ryan P.A., 2010, Householder perspectives and preferences on water storage and use, with reference to dengue, in the Mekong Delta, southern Vietnam, International Health, 2: 136-42

http://dx.doi.org/10.1016/j.inhe.2009.12.007

Journal of Mosquito Research

• Volume 6

View Options
. PDF(321KB)
. FPDF
. HTML
. Online fPDF
Associated material
. Readers' comments
Other articles by authors
. Arooj Aftab Nadeem

. Farkhanda Manzoor