Prevalence, Risk Factors and Geospatial Distribution of Giardia Duodenalis Infection in Dogs in Nairobi County, Kenya

Abstract

Giardia duodenalis, the causative agent of mammalian giardiasis is a zoonotic parasitic infection that poses a serious public health risk. It is associated with diarrhea or loose stool in man and animals. The dog is as a host plays a crucial role in transmission of the infection since it enhances the maintenance of the cyst in the environment. It acts as a carrier, reservoir and transmitter of this parasitic zoonotic infection. In Kenya, G. duodenalis has been detected and diagnosed in children although no animal assemblages were isolated. It has also been detected in cattle. However, there are no studies of the parasite infections in dogs and this study provided the first data supporting its prevalence, potential risk factors and the geospatial distribution in dogs in Nairobi County, Kenya. This was a cross sectional study where faecal samples were collected from randomly selected dogs. A standardized questionnaire was administered to acquire data on risk factors. A multistage random sampling technique was used in the study. The veterinary clinics and KSPCA were the primary sampling units while systematic randomly selected dogs were secondary sampling units. Veterinary clinics sampled client-owned dogs while KSPCA was the catchment area for sheltered dog’s population and the free roaming dogs. A total of 400 faecal samples were collected from November 2018 to October 2019. The samples were then subjected to a G. duodenalis specific serological test called Giardia INDEX SNAP test to determine faecal antigen and hence its prevalence. An overall true point prevalence of 95% confidence interval for G. duodenalis infection was calculated using descriptive statistics. Important risk factors for G. duodenalis infection for each individual dog that included age, ownership (owned vs. sheltered), breed, sex, neuter status, body condition score, faecal consistency, clinical signs and duration, type of food and method of feeding, area of origin, season, nature of housing, purpose of keeping dog, vaccination status, co-infection and deworming status were captured using a standardized questionnaire. General Pocket Radio Service co-ordinates for each dogs’ origin were generated. The heat map using the Giardia status illustrated the geo-spatial distribution of the disease in Nairobi County. Univariate analysis for all the factors was done to determine their association to G. duodenalis infection. Factors with p value ≤ 0.2 were considered to have a significant association and were carried forward to the multivariable logistic regression model at a p value ≤ 0.05 while assessing for confounding and interaction. The overall apparent prevalence of G. duodenalis in Nairobi County, Kenya was 22.25%. The univariate logistic regression analysis showed that 15 factors had positive univariable association (P ≤ 0.2) to the occurrence and transmission of G. duodenalis infection. These were area of dog origin, ownership, breed, age, sex, vaccination ..........................