Giardia duodenalis genotypes among schoolchildren and their families and pets in urban and rural areas of Sinaloa, Mexico

Abstract

Introduction: Giardiasis is a human health concern worldwide, especially among schoolchildren. Giardia duodenalis genotypes A and B are infective to humans, but their zoonotic potential remains controversial. In Mexico, the most prevalent genotype is A, but B was also detected in southeastern Mexico. In Sinaloa state, northwestern Mexico, giardiasis is highly prevalent, but Giardia genotypes have been poorly studied. Methodology: This study aimed to investigate the distribution and clinical-epidemiological correlation of G. duodenalis genotypes in schoolchildren and their families and pets in urban and rural areas of Sinaloa state, Mexico. Results: Among 395 schoolchildren (274 urban, 121 rural), 76 (49 urban, 27 rural) were infected with G. duodenalis. In total, 22 families (15 urban, 7 rural) of infected schoolchildren, consisting of 60 family members (41 urban, 19 rural) and 21 pet dogs (15 urban, 6 rural) were examined; 10 family members (5 urban, 5 rural) and 5 pet dogs (3 urban, 2 rural) of 10 families (6 urban, 4 rural) were infected. After PCR-RFLP analyses of vsp417 and gdh genes, genotype prevalence among infected urban schoolchildren was 79.5% AI, 12.8% AII, and 7.7% mixed AI+B. However, only AI genotype was found in family members and pets. In the rural area, only the AI genotype was detected. Genotypes were not correlated with clinical manifestations. Conclusions: This paper shows the presence of B genotype in northwestern Mexico for the first time. Detection of AI genotype in dogs suggested the possible role of dogs as the reservoir for human giardiasis in Sinaloa, Mexico.

First identification and multilocus genotyping of Giardia duodenalis in pet chipmunks (Eutamias asiaticus) in Sichuan Province, southwestern China

“…In the present study, assemblage A sequences were more prevalent than assemblage G sequences, and no mixed assemblage A and G infections were detected. This result is consistent with data from previous studies in pets in China and Mexico [ 24 , 28 ]. Thus far, assemblages A-C, E and G have been identified in rodents worldwide, and nearly all tested samples contained at least either assemblage A or B [ 12 , 13 ].…”

“…Sub-assemblage AII has also been identified in humans in China. Cross-species transmission of G. duodenalis assemblage AI in Mexico and in Brazil has been recently reported [ 28 , 29 ]. This finding suggests that chipmunks infected with assemblage AI were probably the source of human giardiasis due to frequent contact of the two species in that specific area.…”

Giardiasis Epidemiology

“…Furthermore, due to the high prevalence of Giardia among children, and its higher exposure to dogs in poor seting, it is believed that Giardia has developed zoonotic transmission. This possibility has been reported concordantly by genotyping and molecular studies from Mexico [40], Jamaica [41], and Cambodia [42].…”

Prevalence and molecular characterization of Giardia intestinalis in racehorses from the Sichuan province of southwestern China

“…Other studies have also shown that the prevalence of G . intestinalis was associated with infection of children and foals [ 24 , 28 ]. The difference between the prevalence of G .…”