International Journal of Medicine and Medical Sciences ISSN: 2167-0404 Vol. 2 (11), pp. 232-235, November, 2012. © International Scholars Journals
 

Full Length Research Paper

The association of ABO blood group and urinary schistosomiasis in the Middle Awash Valley, Ethiopia

Ketema Deribew¹ _, Zinaye Tekeste ²* and Beyene Petros³

¹Department of Biology, Bonga Teacher Education College, P. O. Box 91, Bonga, Ethiopia.

²School of Biomedical and Laboratory Sciences, College of Medicine and Health Sciences, Gondar University,

P. O. Box 196, Gondar, Ethiopia.

³Department of Microbial, Cellular and Molecular Biology, College of Natural Sciences, Addis Ababa University,

P. O. Box 1176, Addis Ababa, Ethiopia.

*Corresponding author. E-mail: [email protected]  

Received 08 July, 2012; Accepted 21 November, 2012

Abstract

The present study was carried out in the Middle Awash Valley, Ethiopia to determine if there was any relationship between the blood group of the human host and urinary schistosomiasis. Patients and Urine and blood samples were collected from 370 children (95 infected and 275 healthy controls) aged 5 to 15 to examine urinary schistosomiasis, hemoglobin concentration and to type blood groups. There were 23 (47.9%) blood group A, 11 (22.9%) blood group B and 2 (4.2%) blood group AB children in the severe schistosomiasis category. Blood group O made up only 25% of severe schistosomisis patients compared to 56.3 and 53.1% of the mild and healthy controls, respectively. A significant difference was observed in egg load between children with blood group O, 1.63 (0.39) (mean ± SD) eggs/10 ml urine) and A,1.93 (0.45) eggs/10 ml urine (P = 0.03). Although the mean egg load in children with blood group O was higher than in those with blood group AB, 1.45 (0.21) egg/10 ml urine), the difference was not significant (P = 0.54). As compared to the mild schistosomiasis cases, the case of severe schistosomiasis was more likely to be of type A (SS vs. MS: O vs. A, odds ratio (OR) 0.23, 95% confidence interval (CI) 1.62-11.42) and B (SS vs. MS: O vs. B, OR 0.24, 95% CI 1.24-13.76) than type O. The study showed that on the basis of egg load, used to determine severity of urinary schistosomiasis, children with blood group A and B were highly prone to severe urinary schistosomiasis as compared to children with blood group O.

Key words: ABO blood group, urinary schistosomiasis, egg load, mild schistosomiasis, severe schistosomiasis. 

INTRODUCTION 

Schistosomiasis or biharzia is a tropical disease caused by blood-dwelling fluke worms of the genus Schistosoma. Most infections in human caused by Schistosoma haematobium, S. japomicum and S. mansoni, together with a minor contribution from S. intercalcatum and S. mekongi.

Schistosomiasis is estimated to infect 200 million people around the world while about 600 million are   estimated   to   be   at   risk   of   infection  (World  Health Organization, 1998). In Ethiopia, S.haematobium is endemic in the awash valley (middle and lower awash valley) from Dahitele irrigation scheme on the Amibara/Angele plain to Gewane, Dubti and Assaita area. In the Wabishebele valley (lower Wabi valley), near the Somali border in the villages of Kelafo, Mustahil and Burukur the parasite is reported (Birrie et al., 1998). It is also reported from the western lowlands of Ethiopia such as Kurmuk (Birre et al., 1996).

The relationship between ABO blood groups and susceptibility, resistance, or severity of some diseases has been studied and close correlations demonstrated between blood groups and malaria  (Zinaye  and  Beyene 2010), S. mansoni (Ndamba et al., 1997) and oesophagogastric varices (Amer et al., 1971). However, the effect of the ABO blood group on urinary schistosomiasis has received little attention.

However, some studies reported absence of significant association between urinary schistosomiasis and ABO blood groups (Ndamba et al., 1997; Kassim and Ejezie, 1982; Khattab et al., 1968).

For instance, Kassim and Ejezie (1982) reported no significant association between the ABO blood group and S. haematobium from two hundred and sixty nine individuals in Epe, Nigeria. In contrast, Ndamba et al. (1997), reported that intensity and annual incidence of S. haematobium infection and related organ pathology was significantly higher among children of blood group A and lowest among blood group O children.

These contradictory reports on the association of ABO blood group and urinary schistosomiasis shows the complexity of the interaction between the parasite and the host.

Therefore, the present study was carried out in the Middle Awash Valley, Ethiopia to generate additional data on the association between the blood group of the human host and urinary schistosomiasis.

 MATERIALS AND METHODS

 Study area and population

 The study was conducted in the Middle Awash Valley, Ethiopia. The area is known for long to be infested by the snail intermediate host, Bulinus abysinicus of S. haematobium. The study participants were Afar ethnic group.  Middle Awash is located at 290 km to the east of Addis Ababa and it is endemic for urinary schistosomiasis (Kloos et al., 1978).

A total of 370 children (95 S. hematobium positive and 275 healthy controls) aged 5 to 15 participated in the study.

Of the total 95 S. hematobium patients, those harboring > 50 eggs /10 ml urine were considered as cases with severe urinary schistosomiasis infection (World Health Organization, 1983).

Children aged between 5 and 15 years; who had no history of S. haematobium drug administration in the two weeks prior to screening, who have no  other serious chronic infection, and had ability to give blood and urine samples were included in the study.

Ethical clearance

The study protocol was reviewed and approved by the Ethical Review Committee of the Department of Biology, Addis  Ababa  University. Written  informed  consent  was consent was obtained from parents/caretakers of children and assent from the 15 years olds, after explaining the purpose and objective of the study.

Laboratory diagnosis

Urine analysis

Mid stream urine samples were collected between 10 a.m. and 2 p.m., the pick time of egg passage (World Health Organization, 1998). Children are provided plastic urine cups and asked to bring mid-stream urine. Each cup was given a serial number and the volume was recorded. Urine samples were analysed using the centrifugation method as described by Okanla (1991). Briefly, the samples were left to stand on the bench for about 30 min. Following this, the urine in each sample was drawn off leaving the last 10 ml in the bottle. The content of each bottle was shaken to suspend the sediment and was transferred into a 20 ml centrifuge tube. The tubes were centrifuged at 1000 rpm for 5 min. The supernatant was discarded and the residue was put on a clean glass slide and examined under 10x objective lens of the microscope. Intensity of infection was estimated according to the number of eggs per 10 ml urine.

Determination of haemoglobin concentration

Peripheral blood was collected from a finger prick using a sterile blood lancet and analysed by portable, battery-operated HemoCue Hb 201 analyzer (HemoCue AB, Angel Holm, Sweden).

Blood group determination

Blood grouping test was done by standard hemagglutination techniques (Zoysa, 1985).

Briefly, 10 µl (approximately two drops) of whole blood were placed in two different places of a grease-free clean glass slide on which 10 µl of antisera for blood group A and B (ALBAclone® Anti-A, B, USA) was applied. The blood cells and the antigen were mixed with applicator stick. The slide was then tilted to detect for agglutination and the result recorded accordingly (Zoysa, 1985).

Treatment

Children who were positive for urinary schistosomiasis were treated based on the recommended drug regimen. A single dose of praziquantel (40 mg/kg body weight) was given to treat urinary schistosomiasis. Children with severe anemia were referred to the nearby health post and clinic for treatment and further follow up.

* Significant difference; † ANOVA; NA^≠, not applicable.

Table 2.  Percentage distribution of the ABO blood group types in the study categories.

Data analysis

All raw data was entered in to Microsoft excel data base system. The data then imported to SPSS version 15.0 software for analysis. Chi-square was used to determine association. Difference between means was analysed by ANOVA and odds ratios (OR) were calculated with 95% confidence interval (CI). Values were considered to be statistically significant when P-values were less than 0.05. 

RESULTS

Characteristics of the study participants

A total of 370 school children were included in this study, 95 were found to be infected with S. haematobium and the remaining 275 study participants were not infected by urinary schistosomiasis and are referred as healthy controls. A significant difference was observed in haemoglobin concentration between the mild schistosomiasis, 12.16 (1.39) gm/dl (mean (± SD), severe schistosomiasis, 11.06 (1.63) gm/dl (mean (± SD) and healthy control cases, 12.20 (2.15) gm/dl (mean (± SD) (P =.001) (Table1).

Percentage distribution of the ABO blood group types in the study categories

Out of the 48 severe schistosomiasis cases, 23 (47.9%)

were of blood group A, 11 (22.9 %) were of blood group B and 12 (25%) belonged to blood group O (Table 2).

In   the   mild   schistosomiasis   cases,  there  were  12

(25.5%), 6(12.5%), 2(4.3%) and 27(56.3%) blood group A, B, AB and O patients, respectively (Table 2). Blood group O was the dominant blood type in both mild schistosomiasis (56.3%) and healthy controls (53.1%) (Table 2).

The odds ratios and P values for the frequency of O and non-O blood group types between the three study categories

Compared to the mild schistosomiasis cases, a case of heavy urinary schistosomiasis was more than four times as likely to be of type A as to be of type O (SS vs. MS: O vs. A odds ratio 0.23, 95% confidence interval 1.62 to 11.42) and almost twice more likely to be of type AB as to be of type O (SS vs. MS: O vs. AB odds ratio 0.44, 95% confidence interval 0.28-17.91) (Table 3). As compared to the healthy control cases, the case of severe urinary schistosomiasis was more likely to be of type A (SS vs. HC: O vs. A, odds ratio (OR) 0.30, 95% confidence interval (CI) 1.58 to 7.04) and B (SS vs. HC: O vs. B, OR 0.28, 95% CI 1.48 to 8.84) than type O (Table 3).

Mean egg counts, haemoglobin concentration and ABO blood groups in children with urinary schistosomiasis

Intensity of S. haematobium infection was significantly

higher in children with blood group A (mean (± SD) 1.93(0.45) egg per 10 ml urine) than blood group O (mean (± SD) 1.63(0.39) egg per 10 ml urine) children (P=0.003). Although the mean egg count in children

^X values shown are the odds ratios, [95% CI], (P-value).

Table 4. Mean egg counts, haemoglobin concentration and ABO blood groups in children with urinary schistosomiasis.

* Significant difference; † ANOVA.

with blood group O (mean (± SD) 1.63 (0.39) egg per 10 ml urine) was higher than in those with blood group AB (mean (± SD) 1.45 (0.21) egg per 10 ml urine), the difference was not significant (P = 0.54) (Table 4). Furthermore, blood group O children (mean (± SD) 11.58 (1.62) gm/dl) were found to have lower mean haemoglobin concentration than children with blood group A (mean (± SD) 11.97 (1.72) gm/dl) but the difference was not statistically significant (P= 0.31) (Table 4).