Journal of Gastrointestinal & Digestive System
Open Access

Helminthes are known as parasitic worms [1]. Helminthes of medically important are belong to two phyla: the Platy helminthes as flat worms and the Nematy helminthes or round worms. Platy helminthes are further subdivided into Cestodes and Trematodes [2]. According some literatures, parasitic worms are categorized into three groups: Cestodes, nematodes, and Trematodes [1]. Intestinal protozoa include amoebae, flagellates and some coccidia. There are two diagnostic stages: vegetative or trophozoites stage and dormant or cyst stage. Both the stages may be found in the same specimen [2]. They are distributed all over the world. In developing countries such as Africa their distribution is higher. In Ethiopia almost all areas of the country helminthes are highly distributed. Majority of them are diagnosed microscopically at egg and larva stage according to their species. Microscopic examination of helminthes is the easiest and the simplest technique in stool examination. There are different laboratory techniques to detect helminthes and intestinal protozoa; these include: Buffered Methylene Blue (BMB) wet mount, Eosin wet mount, Concentration methods, permanent staining techniques and Cellophane (Adhesive Tape) preparation. There are also different microscopic examinations (wet mounts) which includes saline mount and Iodine mount, or Wet mount or thick smear technique or sometimes direct smear and Kato-Katz technique called Kakuru technique (also called the Kakuru-Katz technique) are laboratory methods for preparing human stool samples prior to searching for parasite eggs [1-3].

In 1954, Kato and Miura were the first to introduce a new method, the “cellophane thick smear technique” which involved a principle of direct fecal sampling. It is different from the standard direct smear procedure in that a larger amount of fecal sample is employed and cellophane strips are used as cover slips instead of glass [3]. According to some authors, direct smear is a qualitative and Kato-Katz is a quantitative examination method [4].

Effective and efficient technique for the diagnosis of helminthes is essential. Therefore comparison and evaluation of the diagnosing techniques is a crucial procedure prior to the helminthes’ egg findings.

Statement of the problem

Helminthes and intestinal protozoa infection is one of the health burdens in the world. One of the causes of prevalence and distribution of helminthes and intestinal protozoa are inappropriate use and inefficient application of the testing techniques. In developing countries the problem is aggravated. In Ethiopia, the application of appropriate and evaluated testing technique is not understood. Therefore, the prevention and control of helminthes and intestinal protozoa in the country is less effective due to the shortage, the quality problem and lack of evaluated technique.

The accuracy of one technique in identifying individuals with soil transmitted helminthes (STH) and intestinal protozoa infections is limited by day to day variation, in helminthes egg excretion, confusion with other parasites and the laboratory technicians’ experience [5].

The accuracy of other techniques is limited by immeasurable sample volume, time consuming procedures, and unaffordable reagents unequal sensitivity of the techniques to different parasites and specificity of the technique to only a certain parasites. As a result the quality of diagnosing and treating of helminthes infection is low.

Intestinal protozoa and soil transmitted helminthiasis (STH) still to be major problems in health worldwide, especially in the tropical and subtropical regions. Although frequent, these infections are not always trivial. They can be the cause of a wide clinical spectrum ranging from apparently symptom-less infections to life threatening conditions such as intestinal obstruction in Ascaris infection. Therefore, this study is a help to promote and protect the highest attainable standard of health and to facilities for the diagnosis and treatment of helminthes and intestinal protozoa.

There is no any study conducted on the efficiency and sensitivity of soiltransmitted helminthes and intestinal protozoa diagnosing techniques in Ethiopia. Thus, there is a need to generate further sensitivity evaluation on the Wet mount and Kato-Katz techniques for the diagnosis of soil-transmitted helminthes and intestinal protozoa parasites in faecal samples. The objective of the present study was to fulfill the gap between soil-transmitted helminthes and intestinal protozoa diagnosis and application of sensitive technique.

Objective

To assess the Sensitivity and Specificity between stool wet mount and Kato- Katz Techniques

Study design

A Prospective, Cross-Sectional study was conducted to evaluate the sensitivity and Specificity between wet mount and Kato-Katz techniques.

Study area

The study was conducted in Badessa woreda areas of four schools. Badessa is a town and separate woreda in eastern Ethiopia. Located in the West Hararghe Zone of the Oromia Region, at the base of a spur of the Chercher Mountains 40 km south of the Addis Ababa-Djibouti Railway and 65 km east of Awash, this town has a latitude and longitude of 8°54′N 40°47′E Coordinates: 8°54′N 40°47′E with an elevation of 1761 m above sea level. The climate is mostly warm with a dry and a rainy season. Badessa, as the rest of the country, has experienced economic and social changes during the past one decade. As a result, there has been a marked improvement in the life style and in the health status of the inhabitants. Other crops in the area are vegetables, greens, cereals and fruits.

Health care is delivered by government primary health care clinics, health centers and private clinics of different levels started by physicians, public health officers, nurses, medical laboratory sciences personnel’s and druggists.

About 200 students had given stool specimen for both saline wet mount preparation and Kato-Katz preparation per each working day from Monday to Friday at selected schools.

Study period

The study was conducted from February 20, 2018 to July 10, 2018. This includes the entire period of the study including selection of the title and approval, preparation of the proposal, submission and approved training, pre-testing, data collection, data analysis, report preparation, and dissemination of the results etc.

Population

Source population: All primary schools in Badessa woreda, West Hararghe Zone, Eastern Ethiopia.

Study population: All primary school students submitted faecal samples for intestinal Helminths examination.

Sampling procedure and sample size: Random sampling techniques were applied to select the four schools from 11 primary schools found in Badessa Woreda of West Hararghe Zone. Using convenient sampling method, 50 students from four schools a total of 200 students were involved in the study.

Quality assurance

Data and specimen quality assurance: Wet mount and Kato-Katz techniques were carried out by trained one medical laboratory technologist and the principal investigator. Pilot study checking was done at Walinchity primary school before the actual laboratory testing to check the quality of materials, reagents and all entire procedures. Diarrheic samples and anthelminthic medicated participants in the last 15 days before the stool examination were excluded.

Statistical analysis: All data derived from microscopic examinations were compared for the two techniques. Statistical analysis was done using Statistical Package for Social Science (SPSS) statistical software version 15.

Study subjects

This study was based on two hundred stool samples collected from school children aged 6-16 years. The study was conducted on four primary public schools; fifty students were participated from each school. A mean age of 11 years, 67% (134 Females) and 33% (66) Males were tested for the study. The Female to Male ratio of the study was about 2:1.

The Socio-demographic Characteristics of the study subjects were shown according to Table 1 below. The study showed that 76 (38%) of the study subjects were from age group of 6-9 years, 74 (37%) from age group of 10-13 years, and 50 of the study subjects (25%) were from ≥14 years of age group. About 99.5% (199) of the study subjects were from family educational level of grade [1-4]. All study subjects had no the habits of toilet use (100%) and none of them treated with an anthelminthic drugs (100%) before the study was conducted (Table 1).

Table 1: Socio-demographic characteristics of the study subjects of Badessa Woreda, West Haraghe in February, 2018

Other variables such as; drinking water source, finger trimming status, bare footing habits were with directly related to the prevalence of intestinal Helminths in the study subjects.

Table 2 showed the result concordance with different variables and p value of the significant variations.

High parasitic prevalence was observed among the age group of 6-9 years (P=0.000). So, among all ages, this age group was the highest (accounted for about 38% followed by age group of 10-13 Years, 37% and ≥ 14 Years was 25%) (Table 2).

Table 2: Socio-Demographic Characteristics and Personal hygienic habits with Relation to the intestinal Helminths infection in the study population

There were significant Variations of the parasites between the above variables (Table 2): gender P=0.15 (0.021) OR=2.04 [1.12-3.73], Female (0.781[0.626-0.9]) and Male (1.19 [1.1.08-2.35]); Drinking Water source (P=0.000) OR=0.048 (.006-.8); Finger nail status (P=0.000) or 0.110 [.049- .249]; Shoe wearing Habits (P=0.000) OR=6.9 [2.588-18.791] (Table 2).

Toilet use, Treatment status with anthelminthic drugs before the study and Residence with domestic animals excluded from the relations due to the following data: All study subjects had no the habits of toilet using Openair defecations were practicing (100%); None of them treated with anthelminthic drugs before the study was conducted (100%); All study subjects were not live with domestic animals.

Prevalence of intestinal Helminths detected in faecal samples of all the study subjects was summarized with the four schools participated into the study on (Table 3).

Table 3: Prevalence of Intestinal Helminths detected from 200 faecal samples from four Public Primary Schools in Badessa Woreda, West Hararghe Zone.

Helminthic Parasites (Ova/Eggs)

Comparison of faecal samples detected by wet mount and katokatz techniques

A Total of 147 intestinal Helminths Parasitic cases were detected by wet mount and Kato-Katz techniques. From these cases, the Kato-Katz technique detected 147 cases of intestinal Helminths from 123 positive students [100%] whereas; the Wet mount technique detected only 45 [30.6%] which were positive cases by the Kato-Katz technique. There was significant difference between Wet mount and the Kato-Katz techniques [P=0.000]. There was a far apart between the two methods [Kappa value= 0.241] (Table 4).

Table 4: Comparison of the numbers and percentages of cases detected by Wet mount, Kato-Katz and Both Techniques Number of detected cases (Detection Rates, %).

The current study demonstrated that the prevalence of intestinal Helminths were very high in the area when we compared with the previous studies. There were significant variations of all species in all schools (Table 3).

This study demonstrated that the variations of intestinal helminths distribution in the Woreda areas/schools required further study. School 3 primary school is the largest in Schistosoma mansoni due to highly intensified irrigations are developing whereas; School 4 primary school is the largest in Hook Worm infection. All samples were examined by Wet mount and Kato-Katz techniques, according to the standardized procedure described elsewhere [2,6-9]. One slide was prepared per person for each techniques (Wet mount and Kato-Katz techniques), and egg findings from Kato-Katz preparation were conducted 30 minutes after its preparation.

This study has an agreement in Kato-Katz technique Sensitivity with some of the previous studies, however, the study conducted in other areas (10- 17) revealed that Kato-Katz technique was less sensitive for soil transmitted Helminths including Hook Worm infection. The present study found that Kato-Katz technique is more sensitive than Wet mount technique for all intestinal Helminths infections. In contrast to the previous study (4), the present study examined a single slide per person and concluded that the Kato-Katz technique when used with the Wet mount is Sensitive, Appropriate and efficient for the examination of intestinal helminthiasis.

As to the relationship between prevalence Sex, the study demonstrated that the infection rate was higher in Females in comparison to Males. The study also demonstrated that the prevalence of intestinal Helminths was related with drinking river water, bare footing, and not trimming finger nail. However, within the limited scope of this study, the relationships between using toilets, family education, antihelminthic treatment, and residence with domestic animal and prevalence of intestinal Helminths were given less attention due according to the following data. All study participants use no toilet (100%), 199 (99.5%) families had grade 1-4 educational level, all participants were not treated with any antihelminthic drug before the study was conducted (100%), and all participants were not live with any domestic animals.

The overall prevalence of Intestinal Helminths in the woreda was 73.5%. This may be due to poor personal and environmental hygiene like other areas of the country.

The most serious consequence of Hook Worm infection is chronic blood loss from the small intestine which leads to iron deficiency anemia, particularly in children and women of childbearing age, whose physiological needs for Iron are greater. In areas where Hook Worm anemia is present, 50% or more of the population may have hemoglobin values below the normal range and some of these may have severed degrees of anemia [10].

The overall prevalence of intestinal Helminths among the study subjects were led by Hook Worm infections with 48.8% followed by Schistosoma mansoni with 38.2%, Ascaris lumbricoides with 19.5% and 13% with Enterobius vermicularis. There were significant variations of the parasites among Schools. School 3 public primary school was the highest prevalence with 214% including multiple infections of Hook Worm and Schistosoma mansoni. School 4 was 48.8% in Hook Worm infections and Hook Worm and Enterobius vermicularis double infections was observed.

This is the first report on the sensitivity of Kato-Katz technique the examination of Hook Worm infection on 30 minutes after preparation.

The current study concluded that the Kato-Katz technique for Schistosoma mansoni and Soil transmitted intestinal Helminths examination in faecal samples. It also a selective technique for field survey to investigate prevalence and drug resistance of the parasites. It seems necessary to indicate that Kato-Katz technique is not appropriate for intestinal examination in areas where the species may exist.

High magnitude of Hook Worm in School 3 and Schistosoma mansoni in School 4 areas calls for immediate intervention. School 1 and School 2 areas also need nonspecific control measures.

The study wants to indicate that a comprehensive control strategy for Helminths infection should include:

• Ensuring wide availability of anithelmintics for Schistosomiasis and soil transmitted Helminth infections in all health services in endemic areas.

• Ensuring good case management of symptomatic cases (example, IMCI).

• Regular treatment of all children at risk, including adolescent girls.

• Through school and community based initiatives.

• Treating pregnant women at risk, through antenatal care and other women’s health program.

• Ensuring a save water supply and adequate sanitation facilities in all schools.

• Ensuring provision of potable water and sanitation facilities at house or community level.

• Promoting good hygiene and sanitation practices among School children and care-givers (Hand washing, finger nail trimming, using of latrines, use of footwear) through community development activities and in school curricula.

Written and Verbal informed consent for participation was obtained from students, teachers and the schools principals as the study poses no risk to them. All those who harbored pathogenic intestinal Helminthic infections were given an anthelminthic drug (Praziquantel) in order to be treated appropriately.

Not applicable (N/A)

The full data for this study is available with the corresponding author when there is a reasonable need.

The author declares that he has no competing interests.

This research work is funded by self. There are no funders who had a role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

The author was conceived the study and involved in the study design, data collection, data analysis, report writing, writing the manuscript and edition of the revised manuscript.

I am grateful to advisors for their unreserved scientific comments, technical support and advice. I also express my gratitude to all study participants and the schools community.

Unlike other studies conducted in many areas of the world, the current study did not consider the parasitic count per person. The smallness of the sample size (200 school Children) was also another draw-back of the current study. Within the limited scope of the current study, there was incapability to determine the specific reason of variations of distribution of the intestinal Helminths in the Woreda except that in School 3 area in which irrigations are highly extended.

1. Dickson Despommier (2016) Wikipedia, the free encyclopedia. Accessed from Columbia University Press.
2. Ochei J, Kolhatkzr A (2003) Medical laboratory science theory and practice. New Delhi: Tata McGraw-Hill, 1st Edition,616-921.
3. Tungtron A, Chiworaporn C, Praewanich R, Radomyes P, Boitano JJ (2007) The potential usefulness of the modified kato-thick smears thechnique in the detection of intestinal sarcocystosis during field survey. Mah Univer J 38(2):232-238.

   [Crossref] [Google Scholar] [PubMed]

4. Santos FLN, Cerqueira EJL, Soares NM (2005) Comparison of the thick smear and Kato-Katz techniques for intestinal helminth infections. Trop Med J 38(2):196-198.

   [Crossref] [Google Scholar] [PubMed]

5. Tarafder MR, Carabin H, Joseph L, Balolong E, Olveda JR et al. (2010) Estimating the sensitivity and specificity of Kato-Katz stool examination technique for detection of hookworms, Ascaris lumbricodes and Trichuris trichiura infections in humans in the absence of a ‘gold standard’. Intern J Parasitol 40:399-404.

   [Crossref] [Google Scholar] [PubMed]

6. Booth M, Vounatsou P, N’Goran EK, Tanner M, Utzinger J (2003) The Influence of sampling effort and the performance of the Kato-Katz technique in diagnosing Schistosoma mansoni and hookworm co-infections in rural coted’ Ivoire. Trop Med Parasitol J 127(6):525-531.

   [Crossref] [Google Scholar] [PubMed]

7. Kongs A, Marks G, verle’P vander stuyft p (2001) The unreliability of the Kato-Katz technique limits its usefulness for evaluation Schistosoma mansoni infections. Trop Med Intern H J 6(3):163-169.

   [Crossref] [Google Scholar] [PubMed]

8. Komiya Y, Kobayashi A (1980) Evaluation of Kato’s thick smear technique with cellophane covers for helminth eqqs in faeces. Jap J Med Sci Boilog 17:57-62.

   [Crossref] [Google Scholar]

9. Cho SY, Lee SH, Rim HJ, Seo BS (1969) An Evaluation of cellophane thick smears Technique for mass stool Examination. K J Parasitol 7(1):48-52.

   [Crossref] [Google Scholar] [PubMed]

10. Xu LQ, Yu SH, Jiang ZX (1995) Soil transmitted helminthiasis: Nationwide survey in china. Bullet WHO 73:507-513.

    [Crossref] [Google Scholar] [PubMed]

11. Men-Bao Q, Ying-Dan C, Song L, Guo-Jing Y, Xiao-Nong Z (2003) Epidemiological investigation clonorchis syinensis in human population in an area of south china. Jap J Infect Dis 56:168-171.

    [Crossref] [Google Scholar] [PubMed]

12. Katz N, Chavez A, Pellegrino J (1972) A simple device for quantitative stool thick smears technique in sxhistosomiasis mansoni. Rev Med Trop Saopaulo 14(6):397-400.

    [Crossref] [Google Scholar] [PubMed]

13. World Health Organization (2002) Prevention and control of schistosomiasis and soil transmited helminthiasis. WHO Techn Rep Ser 912:1-4.

    [Crossref] [Google Scholar] [PubMed]

14. Odongo-Aginya EI, Taylor MG, Sturrok RF, Axkers JP, Doehring E (1995) Field evaluation of an improved kato-katz thick smear Technique for quantitative determination of helmith eggs in faeces. Trop Med parasitol 46(4):275-277.

    [Crossref] [Google Scholar] [PubMed]

15. Ebrahim A, EL-Marshedy H, Omer E, EL-Doly S, Barakot R (1997) Evaluation of the kato-katz thick smear and formol ether sedimentation techniques for quantitative diagnosis of schistosoma mansoni infection. Am J Trop Med Hyg 57(6):706-708.

    [Crossref] [Google Scholar] [PubMed]

16. Borel E, Etard JF, Asso A, Diakite M (1999) Comparison of a digestion-sedimentation technique with the kato-katz technique in the detection and quantification of s. monsoni eggs in light to moderate infections. Parasite 6(2):175-178.

    [Crossref] [Google Scholar] [PubMed]

17. Berhe N, Medhin G, Erko B (2004) Variations in Helminth Faecal egg counts in kato-Katz thick smear and their implications in Assessing infection status with schistosoma mansoni. Acta Trop 92(3):205-212.

    [Crossref] [Google Scholar] [PubMed]

18. AA Escobedo, R Cañete, FA Núñez. Prevalence, risk factors and clinical features associated with Intestinal parasitic infections in children from san Juany Martinez, pinar Del Rio, Cuba. West Indian med J 2008 Sep; 57(4):377-82.

    [Crossref] [Google Scholar] [PubMed]