Immunizing Vulnerable Populations Like Rag Pickers, Garbage Collectors, Municipality Workers and Newspaper Hawkers against Rabies in Shimla Municipality, HP, India

Background: Rabies is a zoonotic disease and many vulnerable sections like rag pickers and municipality workers neglect animal bites due to ignorance of their potential deadly outcomes. Stray dogs abound in garbage pits and this population is exposed to their attacks. It should be a mandate for municipalities to help protect their sanitary workforce, especially rag pickers, from deadly infectious diseases such as Rabies, Hepatitis-B, HIV, Tetanus etc. Objectives: Objective of this study was to study methods to provide pre-exposure Rabies vaccination for such highly exposed populations by engaging them and understanding their perception of this disease through a constant dialogue with them. Methods: We started by engaging with the rag pickers to know how best to entice them to get themselves immunized. We then attempted to search literature for the most practical methods likely to succeed in reducing risk of rabies deaths in this population. Results: WHO approved 3 injections of 0.1 ml tissue culture vaccine on days 0, 7 and 21 were tried but were shown to result in many dropouts among rag pickers for repeat injections. We then followed a method where 0.1 ml of rabies vaccine was injected at 4 different anatomical sited in one setting. This proved acceptable and relatively inexpensive. A small number of subjects were studied by determination of neutralizing antibody by RFFIT, which proved immunogenic having anamnestic response on boosters given single IM or at 4 sites ID subsequently, implying that short schedule rabies pre-exposure vaccination can be done in high risk groups and may save lives if applied to the poorest that are highly exposed.

Effect of experimental single Ancylostoma caninum and mixed infections of Trypanosoma brucei and Trypanosoma congolense on the humoural immune response to anti-rabies vaccination in dogs

Objective:To determine the effect of Ancylostoma caninum(A.caninum)and trypanosome parasites on the immune response to vaccination in dogs in endemic environments.Methods:Sixteen dogs for the experiment were grouped into 4 of 4 members each.Group I was the uninfected control one,and GPII was infected with A.caninum;GPIII was infected with A.caninum/Trypanosoma congolense(T.congolense),and GPIV was infected with Trypanosoma brucei(T.brucei)/A.caninum.The dogs were first vaccinated with antirabies vaccine before infecting GPII,GPIII and GPIV with A.caninum which were done 4 weeks after vaccination.By 2-week post-vaccination,trypanosome parasites were superimposed on both GPIII and GPIV.A secondary vaccination was given to GPI,GPII,GPIII,and GPIV by Week 12 of the experiment(4 weeks post treatment).Results:The prepatent period was(3.00±1.40)days,in the conjunct infection of T.brucei/A.caninum.It was(9.00±1.10)days,in conjunct T.congolense/A.caninum.The prepatent period of A.caninum was(14.0±2.0)days in the single A.caninum group and(13.0±1.0)days in the conjunct trypanosome/A.caninum.At the 1st week after vaccination,the antibody titer in all the vaccinated groups(GPI,GPII,GPIII,and GPIV)significantly increased(P<0.05)and peaked at the 3rd week after vaccination.Following infections,there were marked significant decreases(P<0.05)in the antibody production against rabies in GPII,GPIII and GPIV.The significant decrease(P<0.05)in antibody titer was highest in the conjunct groups(GPIII and GPIV)compared to the single infection(GPII).Treatment with diminazene aceturate and mebendazole did not significantly improve antibody response in the dogs.A secondary vaccination administered at the 12th week after the primary vaccination significantly increased(P<0.05)the antibody titer with a peak at the 3rd week after the secondary vaccination.Conclusions:It was therefore concluded that A.caninum,T.brucei and T.congolense induced immunosuppression in antirabies vaccination in dogs.