training module for medical officers primary health centre - NVBDCP

Entomological parameters should be correlated with epidemiological parameters to get a completepicture of malaria in the area.The entomological data generated in one PHC of the region can be applied to the other close-byPHCs of the region, especially in respect to vector susceptibility, seasonal variation, longevity etc.Adult vector DensityHand Collection MethodMan Hour Hand Captures(Per man hour density)=No. of mosquitoes collectedNo. of man hours spent in searchHigh vector density indicates high potential for malaria transmission.Data on longitudinal studies on vector densities indicate seasonal (weekly / monthly / annual) trendof vector prevalence; its disease transmission potential; vector behaviour (resting indoors /outdoors) and impact of anti-vector measures.Some vectors like An. minimus and An.fluviatilis can transmit even in low densities.Total pyrethrum spray catch density expressed as total catch per hutAn auxiliary method for determining vector prevalence in an area.Useful even in situations of low indoor resting habit of vector(s) as well as where indoor habitatsprovide hiding places not detected through hand capture methods.Man-Mosquito contactHuman Bait: Per bait, per night, per unit time.Indicates differential man feeding propensity, man biting rate of mosquitoes, site of vector mancontact and changes, if any, consequent to indoor residual insecticidal spray.Sporozoite Rate (Per cent)Sporozoite Rate for each species = No. of females positive for sporozoites x 100No. dissectedIt incriminates the mosquito species as malaria vector.It is an indicator of the efficiency of species in malaria transmission in time and space.20