Table 3 Summary of findings of recent similar studies done in other South Asian countries
Place | Year published | Study period | Dengue notified/seropositive | Weather variables studied | Correlation identified |
|---|---|---|---|---|---|
1. Dhaka, Bangladesh [29] | 2014 | 2000–2010 | Notified dengue cases | Tmax, Tmin, rainfall, R.H. | Monthly temperature and humidity were significantly associated with monthly dengue incidence with highest lag effect of four months. |
2. Tamil Nadu, (South) India [30] | 2013 | 2000–2008 | Notified dengue cases | Monthly mean Tmax and Tmin, rainfall | Rainfall and temperature influence dengue incidence. Climatic variance in high incidence and low incidence years does not show any difference. Both rain and drought are conducive to surges of dengue. |
3. Dhaka, Bangladesh [31] | 2012 | 2000–2008 | Notified dengue cases | Rainfall, Tmax, R.H. | Rainfall, Tmax, and R.H. significantly correlated with monthly reported dengue cases. |
4. Lahore (North), Pakistan [32] | 2012 | 2007–2011 | Seropositive dengue | Tmin, Tmean, rainfall, R.H. | Tmin, Tmean, R.H., and rainfall all had significant positive correlation with dengue with four-, six-, and eight-week lags. Strongest correlation with rainfall was with an eight-week lag. Tmax had no significant correlation. |
5. Lucknow, (North) India [33] | 2012 | 2008–2010 | Seropositive dengue (hospital-based study) | Tmin, Tmax. R.H Rainfall | No statically significant correlation between dengue and weather variables. |
6. Manipur, (North East) India [34] | 2012 | 2007–2008 | Seropositive dengue | Tmin, Tmax, morning and afternoon R.H., rainfall | Dengue has not been reported in Manipur until the 2007 outbreak. Changes in the weather were studied between 2005 and 2008, compared to 2000–2004. A significant increase in Tmin, rise of morning R.H, a decrease of afternoon RH, and a decrease of rainfall was found in the 2005–2008 period. |
7. Karachi, (South) Pakistan [16] | 2011 | 2005–2009 | Notified dengue | Rainfall, R.H., temperature | Ambient temperature, humidity and post-monsoon rain results increased mosquito activity with consequential higher incidence of dengue. |