| Abstract|| |
Introduction: The impact of chemotherapy on human intestinal helminthiasis among school children in semi-urban tropical communities of Igbo-Eze South Local Government Area of Enugu State, South-Eastern Nigeria, was investigated. Materials and Methods: Stool samples were obtained from 1296 school children (ages 4-15 years) from six schools randomly selected from the study area. Helminth eggs were recovered from stool samples. Those infected were treated with single oral dose of 400 mg albendazole tablets and re-examined for helminth eggs 4 weeks post-treatment. Results: Out of 1296 school children examined, 106 (8.1%) of the children were significantly (P < 0.05) infected with human intestinal helminths thus: 64 (4.9%) with Ascaris lumbricoides, 33 (2.5%) with hookworm and 9 (0.7%) with Trichuris trichiura. Out of the 64 children infected with A. lumbricoides, there was a reduction in the prevalence of infection by 18.8%. Furthermore, out of the 33 children infected with hookworm, there was a reduction in the prevalence of infection by 15.1%. Out of the nine children infected with T. trichiura, there was a reduction in the prevalence of infection by 22.2%. Conclusion: These findings suggest intestinal helminth specificity to the efficacy of albendazole. Thus, further research into the development of more effective antihelminthic drugs is necessary.
Keywords: Albendazole, Ascaris lumbricoides, chemotherapy, hookworm, human intestinal helminthiasis, rural tropical communities, school children, Trichuris trichiura
|How to cite this article:|
Edelduok EG, Eke FN, Evelyn NE, Atama CI, Eyo JE. Efficacy of a single dose albendazole chemotherapy on human intestinal helminthiasis among school children in selected rural tropical communities. Ann Trop Med Public Health 2013;6:413-7
|How to cite this URL:|
Edelduok EG, Eke FN, Evelyn NE, Atama CI, Eyo JE. Efficacy of a single dose albendazole chemotherapy on human intestinal helminthiasis among school children in selected rural tropical communities. Ann Trop Med Public Health [serial online] 2013 [cited 2020 Jan 22];6:413-7. Available from: http://www.atmph.org/text.asp?2013/6/4/413/127776
| Introduction|| |
Human intestinal helminthiasis is among the most common infections afflicting humans in developing countries. They are one of the world's most important causes of retardation of physical and intellectual growth in children. , Between 500 million and 1 billion people are estimated to be infected annually world-wide.  According to Crompton  an estimated 1472 million persons harbor Ascaris lumbricoides, 1298 millions are infected with hookworm and about 1049 million with Trichuris trichiura. The global estimated prevalence of anemia in hookworm infection and of cognitive impairment in hookworm, Ascaris and Trichuris infections indicated that for each parasite, 10-50 million persons may be affected.  Thus, human intestinal helminthiasis constitutes an important public health problem. Human intestinal helminthiasis can be prevented and controlled through various measures. According to Crompton,  measures to control these infections should be aimed at reducing morbidity. Chemotherapy has been an important measure used in controlling human intestinal helminthiasis. , The approach used in chemotherapy is often the mass treatment of human populations with antihelminthic drugs, a process known as mass drug administration.  World Health Organization (WHO) is actively promoting the approach of using antihelminthic drugs in the community to lower the intensity of human intestinal helminthiasis.  School-age children can benefit at any time from appropriate antihelminthic treatment given to reduce the intensity of infections. , Human intestinal helminthiasis can be treated with different drugs depending on the parasite involved. The efficacy of mebendazole against soil-transmitted nematode infections has been reported to be high.  Other antihelminthic drugs recommended by WHO for the control of soil-transmitted nematodes include albendazole, levamisole and prattle.  However, there have been concerns about the sustainability of deworming with antihelminthic drugs and the emergence of resistance. Thus, many of studies have been carried out to assess the impact of chemotherapy on human intestinal helminthiasis. ,,,,,, This notwithstanding, much still remains to be known about the impact of a single dose chemotherapy on human intestinal helminthiasis especially among infected children of Igbo-Eze South Local Government Area (LGA). Therefore, this study was carried out to investigate the impact of alblendazole chemotherapy on school children infected with human intestinal helminths in Igbo-Eze South LGA, Nigeria.
| Materials and Methods|| |
The study was carried out in rural tropical communities in Igbo-Eze South LGA, Enugu State, Nigeria. The sampled communities were Ibagwa-Aka, Iheakpu-Awka, Iheaka, Ovoko, Itchi and Unadu. The headquarters of Igbo-Eze South LGA is at Ibagwa-Aka. Igbo-Eze South LGA is located between latitudes 7°19’ East and 7°28’ East and longitudes 7°00’ North and 6°53’ North.  The area is in the guinea savannah forest mosaic zone of Nigeria. The study area has two main seasons; the rainy and dry seasons. The rainy season usually starts in April and ends in September while the dry season usually starts in October and ends in March. The soil is moist and porous, which favors the survival of soil-transmitted helminths ova. The inhabitants of this area are mainly subsistent farmers and traders. There are 17 health centers in the area, with a General Hospital at Itchi. The total population of people in the study area is 75,368.  There are 44 primary schools with 14,994 pupils in the study area; 8860 males and 6134 females.  Each of the schools have six classes; primary 1-6.
Selection of schools and pupils
Six schools were used for this study. Primary schools in the study area were listed out and six schools were randomly selected (Township School 1, Ibagwa, Community Primary School 3, Itchi, Central School, Ovoko, Central School, Iheaka, Community Primary School 1, Unadu and Community Primary School, Iheakpu-Awka) using table of random numbers. From each of the six schools selected, 36 pupils were randomly sampled for the presence of helminth egg in fecal matter. Six pupils were selected from each class (classes 1-6) to make up a total of 36. This was done using the register of each class. When any selected pupil was absent, a pupil after the indicated one was sampled for replacement. A total of 1296 pupils were sampled at the end of 6 months (July-December 2005).
Informed oral consent was obtained from the pupil and headmasters/headmistresses of the schools. In addition, a meeting was held with the parents/guardians of the pupils, informing them of the importance of the study and seeking for their consent. Any pupil not willing to take part in the study was excluded. Pupils who were positive for human intestinal helminths were treated with appropriate antihelminthic drugs using trained nurses. The study was approved by the University of Nigeria Teaching Hospital Research Ethics Committee.
Collection and examination of stool samples
Stool samples were collected monthly for a period of 6 months. Each of the selected pupils was given a small bottle in which they collected their stool samples. The bottles were labeled with the pupil's name, age and sex. On collection of the stool samples, they were taken to the Parasitology and Public Health Laboratory, Department of Zoology and Environmental Biology, University of Nigeria, Nsukka, Enugu State, Nigeria for examination. At the laboratory, for the diarrheic stool samples, a drop of fresh physiological saline was placed on a slide. Using a tooth peak, a small amount of a stool sample was mixed with saline and examined under the microscope using first, the ×10 objective followed by ×40 objectives to identify the eggs.  For the non-diarrheic stool samples, the formol-ether concentration technique was employed.  Using a stick, 1 g of the stool sample mixed with physiological saline was put in a screw-cap bottle containing 4 ml of 10% formol water. The bottle was capped and mixed by shaking for about 20 s. Thereafter, the stool sample was sieved and the suspension collected in a beaker. The suspension was transferred to a tube and 3 ml of ether was added. The tube was stoppered and mixed by shaking for 1 min. Thereafter, the stopper was removed and centrifuged immediately at 3000 rpm for 1 min. After centrifuging, four layers were evident; the top layer of ether, thin layer of debris, formalin and sediment in the bottom with parasites. An applicator stick was used to loosen the layer of stool debris from the side of the tube. The ether, debris and formalin were then carefully poured off. The sediment was mixed, transferred to a slide and covered with a cover glass. The slide was examined under the microscope using first, the ×10 objective followed by ×40 objective to identify the eggs. , Infection was defined by the presence of eggs of human intestinal helminths in the stool samples. The number of pupils infected with human intestinal helminthiasis and the type of human intestinal helminths' eggs observed were recorded. 
Pupils found to be infected with intestinal helminths were administered with single oral doses of 400 mg albendazole tablets. Their stool samples were collected again after 4 weeks post-treatment and examined for the presence or absence of intestinal helminths. Treatment was said to be effective when the parasites were not observed and ineffective when parasites were observed during the examination. ,
Differences in the prevalence of infection were determined using the χ2 test from the contingency tables. χ2 test was also performed to compare the effectiveness of treatment on the different human intestinal helminths recorded during the study. The analysis was performed using Statistical Package for Social Sciences (SPSS) version 22.0 (IBM SPSS, IBM Corporation, Armonk, New York 10504-1722, USA).
| Results and Discussion|| |
Human intestinal helminthiasis is important health problems in the school-age population. This study has shown that human intestinal helminthiasis is prevalent among school children in the study area. Of the 1296 school children examined for human intestinal helminthiasis, 106 (8.1%) were infected thus; 64 (4.9%) were infected with A. lumbricoides, 33 (2.5%) were infected with hookworm, while 9 (0.7%) were infected with T. trichiura. However, within the infected group, the prevalence was 60.4%, 31.1% and 8.5% for A. lumbricoides, hookworm and T. trichiura infections, respectively [Table 1]. There was a significant difference in the prevalence of infections among the school children (P < 0.05). The higher prevalence of A. lumbricoides infection than hookworm and T. trichiura infections was consistent with some previous reports. , This finding has important health implications for morbidity and transmission rates. The treatment of school children who had intestinal helminths infections with single oral dose of 400 mg albendazole tablets led to reduction in the prevalence of intestinal helminth (18.8% for A. lumbricoides, 15.1% for hookworm and 22.2% for T. trichiura), but were largely not effective as exemplified by the high prevalence of post-treatment helminths (81.2% for A. lumbricoides, 84.9% for hookworm and 77.8% for T. trichiura) [Table 2]. In contrast with our study, reports of high efficacies of albendazole against human intestinal helminthiasis may be attributed to differences in geographical locations, climatic conditions and hygiene; which scored low among the sampled pupils. ,,,, Nevertheless, Hall and Nahar  had shown that single oral dose of 400 mg albendazole gave cure rate of less than 40.0% for A. lumbricoides and T. trichiura in children in Bangladesh. Moreover, the low cure rate of albendazole against trichuriasis (22.2%) observed in this study was consistent with that of Adams and others who reported of low efficacy of a single dose of albendazole against trichuriasis.  Treatment failures recorded after 4 weeks of treatment may be attributed to re-infection, resistance of the parasites to drugs and decline in the efficacy of the drug. This signals the need for close monitoring of the performance of the drug against human intestinal helminth parasites in the area. Re-infection is usually an important factor in treatment. Elkins and others reported A. lumbricoides re-infection reaching 55% of pretreatment rates.  Quinnell and others reported of rates of hookworm re-infection reaching 80% of pretreatment rates,  while T. trichiura re-infection had been reported to reach 44% of pretreatment rates.  Similarly, Albonico et al. reported high rates of post-treatment re-infection for human intestinal helminths in areas of high endemicity.  It is possible that re-infection may have occurred due to poor sanitary conditions and lack of proper health education. , Despite re-infection however, regular treatment to reduce the worm burden consistently could prevent some of the morbidity associated with chronic infection.
|Table 1: Prevalence of human intestinal helminths among school children in the study area|
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|Table 2: Effectiveness of treatment of infected children with drugs (single oral dose of 400 mg albendazole tablets) in the study area|
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Furthermore, it is possible that the parasites may have developed resistance to the drug. This possibility needs to be explored; using methods such as the egg hatch assay  to assess the susceptibility of intestinal helminths to albendazole. Also, the possibility of combining this drug with another effective antihelminthic drug to prolong its useful therapeutic life should be explored. Albonico et al. noted that combination therapy with drugs with differing modes of action is an alternative strategy to improve efficacy and lower the risk of resistance.  Indeed, Mani et al. had reported high efficacy of co-administration of albendazole and diethylcarbamazine against geohelminthiasis,  while Belizario and others also reported high efficacy of a combination of albendazole and ivermectin and a combination of albendazole and diethylcarbamazine, against trichuriasis compared with a single dose of albendazole. 
The use of new drugs in treating human intestinal helminthiasis should also be explored. Already, nitazoxanide, a nitroimidazole compound that is increasingly used in children with giardiasis and cryptosporidiosis, is being explored as a broad-spectrum antiparasitic agent with antihelminthic properties.  In randomized studies in China, tribendimidine, a drug with low toxicity and broad-spectrum activity against many human intestinal helminthiasis, was found to be equivalent to mebendazole and albendazole for the treatment of A. lumbricoides, T. trichiura and hookworm infections and was better than these drugs for N. americanus infection.  However, the implementation of these measures must take into account, cost considerations and affordability in view of the weak economic background of rural communities where the drug is mostly needed.
This study has shown that human intestinal helminth was prevalent among school children in Igbo-Eze South LGA, Enugu State. Even though the treatment failures recorded in the study may have been due to re-infection, the possibility of a decline in the efficacy of albendazole in treating human intestinal helminthiasis and possibly, resistance of the parasites to the drug, should not be overlooked. Efforts at developing and testing new control tools should be intensified. Vaccination, which offers the possibility of a simple, single step for the interruption of infection, disease and transmission, should be explored. Further investigations on the efficacy of the different antihelminthic drugs against human intestinal helminthiasis are necessary since these drugs are widely used for preventive chemotherapy. Moreover, health education and improvement of sanitary conditions should be encouraged since chemotherapy alone cannot efficiently control the transmission of infections in the community. These efforts could lead to substantial reductions in the disease burdens due to human intestinal helminthiasis.
| Acknowledgement|| |
We are thankful to Chief and Mrs. Asuquo Ekpeyong, parents of the first author for partially funding the study. We are grateful to the head teacher, teaching staff and pupils of the various primary schools in Igbo-Eze South LGA, Enugu State, Nigeria for their various contributions during the study. We are also thankful to the Department of Zoology and Environmental Biology, University of Nigeria for the provision of laboratory space, equipments and analytical packages for the study and Miss Nkechinyere Onah, Department of Zoology and Environmental Biology, for typing the manuscripts. There is no conflict of interest among the authors and with any organizations.
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Joseph Effiong Eyo
Department of Zoology and Environmental Biology, University of Nigeria, Nsukka, Enugu State
Source of Support: None, Conflict of Interest: None
[Table 1], [Table 2]