Suma Ghosh

• Ph.D
• Professor (Assistant) at Shiv Nadar University

Understanding the mechanisms that generate complex host-parasite interactions, and how they contribute to variation between and within hosts, is important for predicting risk of infection and transmission, and for developing more effective interventions based on parasite properties. We used the T. retortaeformis (TR)-rabbit system and developed a s...

Schematic of the experimental setup. We performed a laboratory experiment by infecting the European rabbits (Oryctolagus cuniculus) with their common intestinal helminth Trichostrongylus retortaeformis. Animals were orally trickle dosed every 7 days with 400 infective third stage larvae (L3) where control animals were orally treated with tap water....

Sensitivity analysis of the parameters. In the main text, we present a model that assumes 3% of eggs shed in the feces are counted, based on 30g dry weight of feces produced per day. Each panel gives the central 95% of the sampled posterior distribution for pre-treatment (lower line) and post-treatment (upper line) animals assuming that observed eg...

Summary table for the GLMM that represents the relation between eggs in the utero and parasite body length in S2 Fig. The number of eggs per female parasite is modeled as a function of parasite length (mm) and experimental phase (pre- and post-) with a random effect the rabbit from which parasites were sampled. We used a log-link function and Poiss...

Relationship between eggs in utero and adult parasite body length in females from the pre(solid curve)- and post(dashed curve)-treatment phase. A random number of T. retortaeformis specimens were collected from the small intestine of rabbits at every sampling point and their body length and number of eggs in utero -for the females- were measured us...

Prior distributions for model parameters. Prior distributions were uniform on a transformed scale. (PDF)

Likelihood ratio tests of alternate models for Egg per Gram (EPG) of feces. The base model includes only the sampling date (week), subsequent models include all variables in the rows above. In all models, the rabbit from which parasites were sampled, was treated as a random effect. (PDF)

Parameter estimates from EPG (the longitudinal data) only. Panels give the sampled posterior distribution, conditional on the observations from all rabbits, for (a) baseline establishment, γ1, (b) effect of cumulative exposure on establishment, γ2, (c) effect of parasite intensity on establishment, γ3, (d) maximum daily clearance, β1, (e) effect of...

Likelihood ratio tests of alternate models of female parasite length. The base model includes only the sampling date (DPI), subsequent models include all variables in the rows above. In all models, the rabbit from which parasites were sampled was treated as a random effect. (PDF)

Sub-model frameworks for the parasite population dynamics. Here, we present the two sub-models that are nested within the full population dynamic model presented in the main text. (PDF)

Comparison of full and sub-models. In the main text, we present a model with effects of both cumulative parasite burden and parasite intensity on both larval establishment and adult clearance. Each panel gives the central 95% of the sampled posterior distribution for pre-treatment (lower line) and post-treatment (upper line) animals for the intensi...

ANOVA table to test alternate models for total number of adult parasites per rabbit. The base model includes only the sampling date (DPI), subsequent models include all variables in the rows above. (PDF)

Background/Question/Methods The rapid clearance or long term persistence of parasites within hosts is determined by the interaction of both parasite life-history characteristics and the immune response of the host to infection. The duration of parasite infection and shedding in turn affects patterns of transmission at the host-population level. Usi...

Transmission of insect-borne diseases is shaped by the interactions among parasites, vectors, and hosts. Any factor that alters movement of infected vectors from infected to uninfeced hosts will in turn alter pathogen spread. In this paper, we study one such pathogen-vector-host system, avian malaria in pigeons transmitted by fly ectoparasites, whe...

The interrelationship between pathogen infection and host mobility is of great importance for successful spread of disease in spatial pest population. As spread of infection depends on horizontal transmission of pathogen, there are numerous factors like susceptibility, latent period, host movement that influence overall effectiveness of the control...

We introduce an algebraic structure called bisemiring and observe that bisemirings arise quite naturally in the literature of abstract algebra. We study some special classes of bisemirings, especially which are arising as generalizations of Boolean algebras and l-groups, and characterize the class of bisemirings which are subdirect products of them...