Name: Beatriz Aira Jacob
Student ID: 6536449
1. How the mosquito can transmit the pathogen?
In general, vector-borne diseases are transmitted through the following mechanisms: mechanical transmission, in which pathogenic microorganisms are carried from the vector’s body to the food consumed by the human host; and biological transmission, in which the pathogen develops inside the vector’s body. In malaria, for example, mosquitoes transmit the pathogen through biological transmission. Accordingly, there are three specific ways in which mosquitoes can transmit the pathogen. Vertical transmission occurs when the mosquito passes the pathogen onto the surface or embryo of its eggs. Horizontal transmission happens when a mosquito takes a blood meal from a pathogenic host then transmits the pathogen to another host, and a new mosquito feeds from the new host. Venereal transmission takes place when the pathogen-carrying female mosquito mates with a male mosquito.
2. What tool and how to determine the malaria transmission?
It is essential to determine malaria transmission to predict epidemiological situations and to reduce outbreaks as much as possible. For this to be possible, vector surveillance and a number of tools are being utilized to obtain and quantify all components of malaria transmission.
The main component is vectorial capacity, which expresses the potential of the Anopheles mosquito to transmit sporozoites to the human host. This is measured through the following determinants: abundance, host preference, host-feeding patterns, reproductive capacity, longevity, dispersal, and distribution of the Anopheles mosquito in the surveillance area. In addition, it also takes into account the susceptibility and competence of the Anopheles mosquito to be the vector of Plasmodium spp. Vector susceptibility relies on the detection of the infective stage in natural samples, susceptibility in a laboratory setup, human biting preference, and abundance in the endemic area. Meanwhile, vector competence weighs in the virulent factors beneficial to pathogens versus the factors beneficial to the host. Furthermore, the following are some of the factors in defining the level of transmission in the area: anthropophilic/zoophilic ratio (to show the feeding preference on humans over other animals), hourly bite rate (to deduce which time of the day the mosquito is most active), incident rate ratio (to determine the place with the highest likelihood the mosquito will bite), and entomological inoculation rate (to determine the infective bites per person per month).