Propped up by localised outbreak of dengue in Patharibagh area, the number of cases of disease in Dehradun district crossed the 200 figure mark on Thursday. On Thursday, the number of dengue cases jumped to 223 in the State Capital. The first dengue patient of the season in Dehradun was reported on July 13 but the outburst of the disease thereafter ensured that the number of cases hit double century in only 21 days.
The health experts are also intrigued by rapid increase in number of dengue cases in such a short span of time. The health department officials confirmed that they have never witnessed such a rapid increase in number of cases with the onset of monsoon in Dehradun in past.
The departmental data reveals that dengue cases are usually reported from the month of August onward and the season lasts till end of October. Dehradun reported 839 cases of dengue in the last season.
An expert in communicable diseases and in charge of Integrated Disease Surveillance Programme (IDSP), Dr SS Kandari told The Pioneer that the travel history of the affected people indicate that they got infection from within the city only.
The health department also records travel histories of the patients and it came out that almost all the patients of the disease in Patharibagh area had not travelled to other dengue infected areas recently which indicate that the infection was endemic (localized). Dr Kandari said that concentration of the disease in a particular area is due to a phenomenon called Tran Ovarian Transmission.
In it the eggs of the dengue infected female of previous season get hatched in large numbers on attainment of favorable conditions.
These eggs though laid in last season had developed a cyst around themselves and they undergo a phase of dormancy to ward off non favorable phase. On attainment of favorable conditions with the onset of monsoon these eggs got hatched and released mosquitoes infected with virus in large numbers. Since concentration of these mosquitoes is more in a particular area local outbreak of the disease is reported.
The district vector borne diseases officer, JP Bahuguna also confirmed theory of Trans Ovarian Transmission for local outbreak of disease in Patharibagh area. He said that 139 dengue patients alone have been reported from Patharibagh area of the city till date. The department has collected 1048 blood samples of from the dengue infested Patharibagh locality ever since the outbreak was reported on July 15.
Thankfully apart from Dehradun (223), Nainital is the only district in the state where the cases of the disease of reported. Here 13 patients have been reported positive for the diseases. It is worth mentioning here that the state health department only considers those cases which are found positive in the Enzyme linked Immunosorbent Assay (ElISA) test.
The district vector borne diseases officer, J P Bahuguna also confirmed theory of Trans Ovarian Transmission for local outbreak of disease in Patharibagh area. He said that 139 dengue patients alone have been reported from Patharibagh area of the city till date. The department has collected 1048 blood samples of from the dengue infested Patharibagh locality ever since the outbreak was reported on July 15.
Thankfully apart from Dehradun (223), Nainital is the only district in the state where the cases of the disease of reported. Here 13 patients have been reported positive for the diseases. It is worth mentioning here that the state health department only considers those cases which are found positive in the Enzyme linked Immunosorbent Assay (ElISA) test.