Incidence of dengue fever in relation to climatic factors in Ludhiana, Punjab.

An outbreak of dengue fever occurred in Ludhiana in 1996 and 1997. A total of 505 patients who attended the hospital attached to Dayanand Medical College, Ludhiana were clinically diagnosed to have dengue fever. Of these, 460 cases were noticed between October and December 1996 while during 1997 only 45 dengue fever cases were observed. Serological examination using dengue IgG and IgM blot was performed with single serum samples of 189 patients. Of these, 129 serum samples were detected positive for anti dengue antibodies. Twenty eight patients died in the dengue epidemic, 12 of whom suffered from dengue haemorrhagic fever (DHF) and six with dengue shock syndrome (DSS). Male patients outnumbered the female patients. Seasonal and cyclic pattern of the disease incidence was observed.