'Inoculation rate', an important vector index for malaria survey, is correctly defined as
man-biting rate multiplied by infective sporozoite rate
The inoculation rate (Entomological Inoculation Rate, EIR) is the number of infective mosquito bites one person receives per unit time. Since only a fraction of biting mosquitoes carry sporozoites, it combines two indices: EIR = man-biting rate x sporozoite rate. If a person gets 10 anopheline bites a night and 2 percent are sporozoite-positive, EIR = 10 x 0.02 = 0.2 infective bites per person per night. It is the best entomological measure of malaria transmission intensity and of the impact of IRS and LLINs.
Average anopheline bites per day per person is the man-biting rate, only one component. Percentage of females with salivary-gland sporozoites is the sporozoite rate, the other component. Proportion of freshly fed females containing human blood is the human blood index, which measures anthropophily, not transmission.
Key point: Inoculation rate = man-biting rate x sporozoite rate; distinguish it from human blood index and man-hour density.
Important Questions from Infectious Disease Control & Prevention
As per the Open Vial Policy, partially used multidose vials of which of the following vaccines can be used over more than one immunization session?
1. BCG vaccine
2. DPT vaccine
3. Hepatitis B vaccine
4. Measles vaccine
Select the correct answer using the code given below.
Consider the following statements regarding dengue virus :
1. It has four distinct serotypes.
2. Infection with any one serotype confers lifelong immunity for that virus serotype.
3. Secondary infection with dengue serotype 2 leads to severe form of dengue.
Which of the statements given above are correct?
Consider the following statements regarding dengue :
1. The mosquito becomes infective after an extrinsic incubation period of 8-10 days.
2. Once it becomes infective, the mosquito remains infective for life.
3. The genital tract of the mosquito does not get infected.
Which of the statements given above are correct?
Consider the following statements about Kyasanur Forest Disease (KFD) :
1. It is transmitted by ticks.
2. It was originally called 'pig disease' because of the association with dead pigs.
3. It was first recognized in Karnataka State.
How many of the statements given above are correct?
- In countries with low levels of measles transmission, what should be the appropriate age for starting immuni-zation with measles-containing vaccine (MCV)?
