Frequency of human toxocariasis in Jos, Plateau State, Nigeria

Abstract

The enzyme-linked immunosorbent assay (ELISA) was used to examine sera of 104 Key words: seroprevalence -Toxocara -enzyme-linked immunosorbent assay -Nigeria Toxocara canis is a saprozoonotic parasite capable of infecting man. Infection in man follows the ingestion of embryonated eggs of the parasite with subsequent hatching and migration of the larvae in his tissues. The persistence or migration of T. canis in the tissues of man causes visceral larva migrans, VLM (Beaver 1969).The diagnosis and confirmation of human toxocariasis rely heavily upon serological tests. In this respect the enzyme-linked immunosorbent assay (ELISA) developed by Cypess et al. (1977) and modified by Glickman et al. (1978) has been found to be very useful in different parts of the world (De Savigny et al. 1979, Glickman et al. 1979, Matsumura & Endo 1983, Garcia et al. 1989, Abo-Shehada et al. 1992, Hakim et al. 1992, Chomel et al. 1993, Holland et al. 1995 because of its high sensitivity and specificity in the routine diagnosis of human toxocariasis.The purpose of this paper is to report on the first serological diagnosis of human toxocariasis in Nigeria and the importance of the disease as a public health problem in the tropical environment. MATERIALS AND METHODSSerum samples -The sera of 104 subjects comprising of 54 males and 50 females, aged between 2 and 24 years were collected between June 28 and July 4 1996. Twenty two of the subjects (15 This work was supported in part by the Faculty of Natural Sciences, University of Jos, research grant no. UJ/ FNS/RG/94-95/13. + Corresponding author. E-mail: ajayi j @ unijos.edu.ng Received 6 April 1999 Accepted 11 November 1999 males and 7 females) were inpatients of the Jos University Teaching Hospital, 58 (29 males and 29 females) were pupils of the Jos University Primary School, 15 (5 males and 10 females) were students of the Jos University Demonstration Secondary School, and 9 (5 males and 4 females) were volunteers. Before the collection of sera, signed consent were obtained from the subjects or their parents or guardians. Information about geophagia (soil pica) and dog ownership were obtained by direct interrogation of the subjects and or their parents or guardians. Six of the subjects had parasitological proven helminthiasis which included ascariasis, taeniasis, trichuriasis and hookworm infections.After collection, serum samples were stored at -20 o C until required.Positive and negative control sera and Toxocara ES antigen were gifts from Dr Guus Van der Lugt, Institute of Infectious Diseases and Perinatal Screening, Bilthoven, The Netherlands.The ELISA -The ELISA was carried out in two 96 well polystyrene microtitre plates (Maxisorb, Nunc, Weisbaden, Germany). An amount of 100 µl of the antigen diluted 1:30 in carbonate buffer, pH 9.6 was added to each well. Then the plates were left opened and incubated overnight at 37 o C. The plates were washed five times with phosphate buffered saline (PBS) containing 0.05% Tween 20 (PBST). After discarding the washing fluid, 100 µl of the ...

Frequency and risk factors for toxocariasis in children from a pediatric outpatient center in southeastern Brazil

“…MUNDIM et al 34 report that in addition to T. cati, cats may also be infected with T. canis, and although T. canis accounts for the greater part of larva migrans in human beings, T. cati is apparently responsible for ocular and visceral changes 20 . In this study, geophagy and contact with soil did not to contribute to the risk of infection by toxocariasis, contradicting findings by AJAYI et al 2 showing highly significant association between seropositivity and geophagy. Contact with soil tended to be associated with risk of infection by the parasite; however, the association was not statistically significant (Odds ratio = 2.23/CI = 0.89 -5.61).…”

“…Some areas with a high prevalence of human Toxocara infection do not show significant differences according to age 2 . In the present study, the mean age of the seropositive children was 5.8 years old (standard deviation of 3.8 years).…”

Related factors to human toxocariasis in a rural community of Argentina

“…Similar findings have been reported by other authors in studies carried out in Taiwan (Fan et al 2004 a), Argentina (Alonso et al 2000), Nigeria (Ajayi et al 2000), and Venezuela (García-Pedrique et al 2004). …”

“…However, Woodruff et al (1978) and Ajayi et al (2000) did not find association between dog owners and seropositivity for toxocariasis.…”

Human Toxocariasis in Rural Brazilian Amazonia: Seroprevalence, Risk Factors, and Spatial Distribution

“…[32][33][34] Young age, 35 low socioeconomic status, 36 low parental education, 34,37 and poor sanitation 6 are additional factors contributing to Toxocara exposure in some communities. Dog ownership has been identified as a risk factor in several 11,27,35,[37][38][39] although not all 40 studies of urban and rural populations. None of these known risk factors, except for young age, was significantly associated with Toxocara exposure in our population (P values between 0.338 and 0.921 in multivariate models).…”