ABSTRACT
@#Introduction: Dengue fever is caused by the dengue virus that is transmitted via Aedes mosquitoes. The lifecycle of Aedes mosquitoes is affected by the local climate (rainfall) which influences dengue transmission. Sabah is one of the states that is laden with a high incidence rate of dengue in Malaysia and the condition seems to have worsened with sudden, multiple outbreaks occurring in the year 2016. Methods: An ecological analysis was conducted in Keningau, Sabah to analyse dengue case patterns and distribution over a 5-year period and to exhibit the correlation between rainfall, larval indices, dengue incidences, and outbreaks. Results: Significant cross-correlation analysis (CCF) was discovered between rainfall and Aedes index at lag number 5 with a correlation coefficient of 0.151 (±0.063) as well as between rainfall and Breteau Index at lag number 5 with a correlation coefficient of 0.143 (±0.063). However, no significant cross-correlation analysis was found between Aedes index and dengue incidences. Associations were also seen between larval indices and outbreak cases. Conclusion: This study showed an increase of Aedes and Breteau Indices to susceptibility level five weeks after rainfall which increases the risk of dengue transmission.
ABSTRACT
Background: Major determinant of dengue incidence is interaction between ecology, vector bionomics, and social factors. Objectives: The objective of the study is to find out bio-eco-social determinants of Aedes breeding. Methods: Background, household, entomological, and knowledge, attitude, and practice (KAP) surveys were undertaken post- and premonsoon showers from May to June 2016 in urban and rural practice area of medical college. Results: A total of 181 and 204 households, 131 and 137 individuals, and 1250 and 1268 water-holding containers were included in household survey, KAP survey, and larval survey in urban slum and rural area, respectively. In both locations, maximum water-holding containers were indoors (41.4% and 61.8%, respectively); however, maximum positivity was peridomestic (63.6% and 83.1%, respectively). Pupae per container were 0.9 and 1.9 in respective locations and pupae per person were 1.2 and 2.3, respectively. Container positivity was seen in containers with rain as water source (8.8%) as well as among those who were never used (10.7%). Irregular water supply was significantly more in rural area (P < 0.05). KAP survey revealed that majority (90.1% and 71.5%, respectively) had heard about dengue, with significantly higher knowledge in urban slum, and television was the main source of information. Majority (89% and 83%, respectively) were unaware that peak biting time of Aedes is daytime. Use of mosquito repellent coils was the predominant preventive practice (46.6% and 61.2%, respectively). Pupae were reared; all were found to be Aedes aegypti. Conclusions: Despite enhanced awareness campaigns, an integrated vector management approach is required for prevention of dengue.
ABSTRACT
<p><b>OBJECTIVE</b>To investigate the prevalence of container breeding mosquitoes with emphasis on the seasonality and larval habitats of Aedes aegypti (Ae. aegypti) in Makkah City, adjoining an environmental monitoring and dengue incidence.</p><p><b>METHODS</b>Monthly visits were performed between April 2008 and March 2009 to randomly selected houses. During each visit, mosquito larvae were collected from indoors and outdoors containers by either dipping or pipetting. Mosquitoes were morphologically identified. Data on temperature, relative humidity, rain/precipitations during the survey period was retrieved from governmental sources and analyzed.</p><p><b>RESULTS</b>The city was warmer in dry season (DS) than wet season (WS). No rain occurred at all during DS and even precipitations did fall, wetting events were much greater during WS. Larval survey revealed the co-breeding of Aedes, Culex and Anopheles in a variety of artificial containers in and around homes. 32 109 larvae representing 1st , 2nd, 3rd, and 4th stages were collected from 22 618 container habitats. Culicines was far the commonest and Aedes genus was as numerous as the Culex population. Ae. aegypti larval abundance exhibited marked temporal variations, overall, being usually more abundant during WS. Ten types of artificial containers were found with developing larvae. 70% of these habitats were located indoors. 71.42% of indoor containers were permanent and 28.58% was semi-permanent during WS. Cement tanks was the only container type permanent during DS. Ae. aegypti larval indices (CI, HI, BI) recorded were greater during WS.</p><p><b>CONCLUSIONS</b>Taken together, these results indicate a high risk of dengue transmission in the holy city.</p>