ISSN: 2161-069X

Journal of Gastrointestinal & Digestive System
Open Access

Our Group organises 3000+ Global Conferenceseries Events every year across USA, Europe & Asia with support from 1000 more scientific Societies and Publishes 700+ Open Access Journals which contains over 50000 eminent personalities, reputed scientists as editorial board members.

Open Access Journals gaining more Readers and Citations
700 Journals and 15,000,000 Readers Each Journal is getting 25,000+ Readers

This Readership is 10 times more when compared to other Subscription Journals (Source: Google Analytics)
  • Research Article   
  • J Gastro intest DigSyst, Vol 12(6)
  • DOI: 10.4172/2161-069X.1000692

The Sensitivity and Specificity Comparison between Stool Wet Mount and Kato-Katz Techniques for the Detection of Intestinal Helminths

Amsalu Mekonnen Wolde*
Department of Medical Laboratory Science, Ambo University, Ethiopia
*Corresponding Author: Amsalu Mekonnen Wolde, Department of Medical Laboratory Science, Ambo University, Ethiopia, Email: amwopportunity@gmail.com

Received: 10-Jun-2022 / Manuscript No. JGDS-22-66391 / Editor assigned: 13-Jun-2022 / PreQC No. JGDS-22-66391 (PQ) / Reviewed: 27-Jun-2022 / QC No. JGDS-22-66391 / Revised: 04-Jul-2022 / Manuscript No. JGDS-22-66391 (R) / Published Date: 11-Jul-2022 DOI: 10.4172/2161-069X.1000692

Abstract

Background: In this study the efficiency and sensitivity of stool wet mount and Kato-Katz smear techniques for the diagnosis of intestinal helminthes were compared in order to detect the human intestinal helminths.

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

Methodology: A total of 200 stool specimens were collected from school children aged 6 to 16 from four primary schools randomly selected in Badessa woreda, West Hararghe Zone, Eastern Ethiopia. Each specimen was smeared on one slide for every technique with a normal saline for wet mount and a cellophane cover for Kato-Katz technique. The overall prevalence of the parasites in each school of the Woreda was determined.

Result: The overall sensitivity of both techniques was calculated. Finally the evaluation of Sensitivity and Specificity of both techniques was interpreted as Kato-Katz technique is more effective and sensitive than stool wet mount technique.

Conclusion: To detect the intestinal helminths especially from carriers and non-symptomatic patients Kato-Katz technique is the selective and sensitive method.

Keywords: Sensitivity; Specificity; Wet mount method; Kato-Katz method

Introduction

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

Materials and Methods

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.

Results

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

Variable Group Investigated Students Percentage (%)
Gender Female 134 67
Male 66 33
Total 200 100
Age Group 6-9 Years 76 38
10-13 Years 74 37
≥14 Years 50 25
School Name School 1 50 25
School 2 50 25
School 3 50 25
School 4 50 25
Total 200 100
Family Education level Grade 1-4 199 99.5
Grade 5-8 1 0.5
Total 200 100
Finger nail Status Trimmed 129 64.5
Not trimmed 71 35.5
Total 200 100
Drinking water Source River 139 69.5
Well 61 30.5
Total 200 100
Shoes Wearing Habits Occasional 90 45
Not at all 110 55
Total 200 100

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

Variables Group Positive (%) Negative (%) Total (%) P value
Gender Female 90 (67.2) 44 (32.8) 134 (67.0) P=0.015(0.021) OR 2.04[1.12-3.73] F=0.781 (0.626-0.9) M=1.19[1.08-2.35] P=0.000
Male 33 (50.0) 33 (50.0) 66 (33.0)
Total 123 (61.8) 77 (38.5) 200 (100)
6-9 Years 72 (94.7) 4 (5.3) 76 (38.0)
Age Group 10-13 Years 40 (54.1) 34 (45.9) 74 (37.0)
≥ 14 Years 11 (22.0) 39 (78.0 50 (25.0)
Total 123 (61.5) 77 (38.5) 200(100)
Drinking Water Source River Water 36 (25.9) 103 (74.1) 139 (69.5) P=0.000 OR=0.048Neg.= .753[.679-.851]Pos.=15.79[2.21-2.616] P=0.000 OR=0.110(.019-.249)
Well Water 1 (1.6) 60 (98.4) 61 (30.5)
Total 37 (18.5) 163 (81.5) 200 (100)
Finger nail Status Trimmed 60 (46.5) 69 (53.5) 129 (64.5)
Not Trimmed 63 (88.7) 8 (11.5) 71 (35.5)
Total 123 (61.5) 77 (38.5) 200 (100) P=0.000 OR=6.9[2.588-18.79] Neg.=1.33[1.17-1.516] Pos.=.191[0.078-0.47] P=0.385 OR=1.4=0.987[.962-1]
Shoes Wearing habits Occasional 5 (5.6) 85 (94.0) 90 (45.0)
Not at all 32 (29.1) 78 (70.9) 110 (55.0)
Total 37 (18.5) 163 (81.5) 200 (100)
Family Education Grade 1-4 123 (61.8) 76 (38.2) 199 (99.5)
Grade 5-8 0 (0.0) 1 (0.5) 1 (0.5)
School Names School 1 31(62.0) 19 (38.0) 50 (25.0)
School 2 9 (18.0) 41(82.0) 50 (25.0)
School 3** 62 (124) 5 (10.0) 67 (33.5)
School 4* 45 (90.0) 5 (10.0) 50 (25.0)
Total 147 (73.5) 70 (35.0) 217(108.5)
*Multiple Infections of: Hook Worm + Enterobius vermicularis 7 (3.5%) **Hook Worm + Schistosoma mansoni 17 (8.5%) Total 24 (16.3%)

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.

Schools No of Students Examined Ascaris lumbricoides Enterobius vermicularis Hook Worm Schistosoma mansoni Total
School 1 50 10 (20%) 7 (14%) 12 (24%) 2 (4%) 31(62%)
School 2 50 4 (8%) 2 (4%) 3 (6%) 0 (0.0) 9 (18%)
School 3 50 0 (0.0) 0 (0.0) 17 (34%) 45 (90%) 62 (124%)*
School 4 50 10 (20%) 7 (14%)** 28 (56%) 0 (0.0) 45 (90%)
Total 200 24 (19.5%) 16 (13%) 60 (48.8%) 47 (38.2%) 147 (73.5%)
* Multiple Infections of: Hook Worm and Schistosoma mansoni ** Multiple Infections of Hook Worm and Enterobius vermicularis

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, %).

Helminths [Ova /Egg] Number of Positive Cases [n=147] Positive by Wet mount Only Positive by Kato-Katz Only Positive detection by Both Methods Total
Ascaris lumbricoides 24 0 [0.0] 19 [79.2%] 5 [20.8%] 24
Enterobius vermicularis 16 0 [0.0] 16 [100%] 0 [0] 16
Hook Worm 60 0 [0.0] 34 [56.7%] 26 [43.3%] 60
Schistosoma mansoni 47 0 [0.0] 33 [70.2%] 14 [29.78%] 45
Total 147 0 [0.0] 102 [69.4%] 45 [30.6%] 147 [100%]

Discussion

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.

Conclusion

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.

Recommendations

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.

Ethics Approval and Consent to Participate

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.

Consent for Publication

Not applicable (N/A)

Availability of Data and Material

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

Competing Interests

The author declares that he has no competing interests.

Funding

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 Authors Contributions

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.

Acknowledgements

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.

Limitations of the Study

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.

References

Citation: Wolde AM (2022) The Sensitivity and Specificity Comparison between Stool Wet Mount and Kato-Katz Techniques for the Detection of Intestinal Helminths. J Gastrointest Dig Syst 12:692. DOI: 10.4172/2161-069X.1000692

Copyright: © 2022 Wolde AM, This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Top