Hookworm and Threadworm Infections and Their Association With Hemoglobin and Eosinophil Concentrations in Residents of Salvador-Bahia, Brazil

Abstract

SUMMARYParasitic infections are responsible for substantial mortality and morbidity worldwide. In most healthy individuals, little overt pathology is observed during infection with S. stercoralis. However, the symptoms in advanced cases may include gastrointestinal bleeding. Anemia is most commonly associated with hookworm infection, especially when several hundred worms are present. Our study evaluates the relationship between the hookworm or S. stercoralis infection status and the hemoglobin concentration of individuals examined by a private network of laboratories in Salvador, Bahia, Brazil. We examined 374,120 samples from middle-class individuals living in Salvador City from January 2004 to April 2008. The stool samples were analyzed by the Lutz and BaermannMoraes methods, and the blood samples were analyzed for hemoglobin concentration and eosinophil counting. The prevalence of hookworm and S. stercoralis were 0.27% (1,027) and 0.34% (1,286), respectively. The prevalence of hookworm and S. stercoralis infection was significantly higher in males than in females and increased with age. Eosinophilia was a common laboratorial finding in individuals infected with hookworm and S. stercoralis. The hemoglobin concentration was lower in the hookworm-infected individuals than in non-infected ones, but none of the examined patients were anemic. Lack of anemia could be a consequence of the socioeconomic status of these patients.

Intestinal parasitosis and anaemia among patients in a Health Center, North Ethiopia

“…This conforms to other studies conducted in Mozambique [33], Uganda [15], Bangladesh [37], Nigeria [33], Cameroon [35], Vietnam [19] and Kenya [38]. This might be because Hookworm species (( Ancylostoma duodenale and Necator americanus ) cause significant blood losses through feeding and cause a daily loss into the small intestine of 0.14–0.26 ml and 0.02–0.07 ml/worm, respectively) and oozing of the blood at attachment site [44].…”

Multivariate analysis of factors associated with Schistosoma mansoni and hookworm infection among primary school children in rural Bahir Dar, Northwest Ethiopia

“…Consequently, the odds of hookworm infection was 1.9 times higher in boys than girls. It was in agreement with studies conducted in certain parts of Ethiopia [ 30 , 39 , 40 ] and Brazil [ 41 ]. The higher prevalence of hookworm in boys in our study might be because boys usually help their parents in agricultural activities where shoe wearing is not convenient.…”

Alterations in the lipid profiles and circulating liver enzymes in individuals infected by Schistosoma mansoni

“…This is likely due to the implementation of the Bahia Azul Project in 1996, which deployed water supply networks and sanitary sewage systems and also implemented cleaning efforts in rivers and on beaches, resulting in significant improvements in sanitary conditions and quality of life for the population of the metropolitan region of Salvador 21 . These positive impacts have been detailed in studies confirming a reduced prevalence of parasitic infections in the region 21,22 . Moreover, the municipality's expansion of health care services, combined with the use of schistosomicidal drugs beginning in 2001, also contributed to declining rates of infection.…”