Estimating the sensitivity and specificity of katokatz. The kato katz method is widely used for diagnosing helminth infections in epidemiological surveys, but is known to have a low sensitivity. Nov 23, 20 soiltransmitted helminth infections are a major public health problem. After filling the hole, the template is removed and the remaining sample is covered with a peice of cellophane soaked in glycerol. However, detailed analyses of quality control, including falsepositive and faecal egg count fec estimates.
The katokatz technique was the most sensitive, due to the higher quantity of stool examined sensitivity threshold 24 epg compared with the mcmaster technique sensitivity threshold 50 epg. Assessing stool quantities generated by three specific kato. Assessing stool quantities generated by three specific. However, the katokatz method has low sensitivity, particularly in areas characterised by lowintensity infections booth et al. The laboratorial platform presented good precision, performance diagnostic, and can be used in replacement to the commercial platform for diagnosis of schistosomiasis by pcrelisa. Stool samples from first year students, 912year olds and adults 2055years were analyzed by the katokatz technique for s. More detailed instructions can be found in laboratory manuals and in the who manual on preventive chemotherapy in human helminthiasis. In the kato katz technique faeces are pressed through a mesh screen to remove large particles. Intestinal schistosomiasis and soiltransmitted helminthiasis. However, with the continual decrease of the prevalence and intensity of s. The kato technique is now most commonly used for detecting schistosome eggs. The sensitivity of the thick smear technique was higher than that of the katokatz method for the diagnosis of all helminths except schistosoma mansoni. The mean fecs based on a single kato katz equaled 10,000 epg for a.
Diagnostic accuracy of katokatz and flotac for assessing. Comparison of the katokatz method and etherconcentration. The kato katz technique and auramine stain did not recover any other protozoan species, which were all partly recovered by trichrome stain, direct smear and fec methods. For a double kato katz, the increase in sensitivity was not significant a.
A manual of the kato katz technique was added in the appendix appendix 2. Helmtec kit katokatz method for diagnosis and control of helminthiasis, 500 tests per kit, each kit containing. Comparison of the thick smear and katokatz techniques for. We evaluated the sensitivity of three fecal examination methods, the kato katz kk method, formalinether technique fe and direct smear, for the diagnosis of clonorchiasis. Both a duplicate kato katz and qpcr showed an equal or higher clinical sensitivity compared to a single kato katz for all three sths. Direct parasitological tests, such as the katokatz thick smear technique katokatz or kk, are the earliest diagnosis used for identification of schistosomiasis and are still widely applied nowadays 11.
Diagnostic performance of a single and duplicate katokatz. Thick smear kato katz positive negative sensitivity specificity kappa index. Because eggs may be difficult to find in light infections, a concentration procedure is recommended. The katokatz kk technique is most commonly used for detecting s.
We compared the accuracy of the kato katz method and etherconcentration technique for the diagnosis of soiltransmitted helminth infections. Indeed, the katokatz technique is widely used in epidemiological. Get a printable copy pdf file of the complete article. To describe the correct laboratory procedures for the parasitological diagnosis of s.
The kato katz technique is the most widely used method detecting soiltransmitted helminth eggs in faecal samples. Th e two cases of cryptosporidium were recovered only by auramine stain. The katokatz technique is one acceptable technique. Tanner m, utzinger j 2003 the influence of sampling effort and the performance of the katokatz technique in diagnosing schistosoma mansoni and hookworm coinfections in rural cote divoire. Out of hookworm cases recovered by each of kato katz and fec, one case was recovered by direct smear. Pdf estimating sensitivity of the katokatz technique for the. The mean fecs based on a single katokatz equaled 10,000 epg for a. We assessed the comparability of the average amount of faeces generated by three kato katz templates included in test kits from two different providers. A portion of sieved sample is then transferred to the hole of a template on a slide. Kato katz technique is used for qualitative and semiquantitative diagnosis of intestinal helminthic infestations. Find support for a specific problem on the support section of our website.
Katokatz technique cellophane faecal thick smear pdf, 123kb. In the world, around 120 million people present schistosomiasis symptoms and an estimated 2. The kato katz technique is recommended by who for the diagnosis and quantification of schistosoma mansoni, other humanpathogenic schistosoma species e. The katokatz technique is the most widely used method detecting soiltransmitted helminth eggs in faecal samples. Quality control in the diagnosis of trichuris trichiura and. Usefulness of katokatz and trichrome staining as diagnostic. Comparison of sensitivity and faecal egg counts of mini. Both a duplicate katokatz and qpcr showed an equal or higher clinical sensitivity compared to a single katokatz for all three sths. Later multiply by the appropriate number see inletinformation of the kato set to give the number of the eggs per gram faeces.
Pdf the present study compared the katokatz thick smear and formol ether sedimentation techniques in the diagnosis of schistosoma. Indeed, the kato katz technique is widely used in epidemiological. The kato katz technique is one acceptable technique that has been widely reported in the literature. Research article open access evaluation of realtime pcr. The katokatz technique is widely used for the diagnosis of soiltransmitted helminthiasis in epidemiological surveys and is believed to be an inexpensive method.
However, the kato katz method has low sensitivity, particularly in areas characterised by lowintensity infections booth et al. It cannot be used to identify hookworm eggs because. Comparison between merthiolateiodineformalin and katokatz. In this paper, we compared the standard katokatz kk technique with a traditional fixation method, the merthiolateiodineformalin mif method. Parasitological techniques pdf parasitological techniques pdf parasitological techniques pdf. We assessed the costs related to the collection, processing. The katokatz method is reliable for diagnosis of clonorchis. Schistosomiasis is a debilitating illness, due to schistosoma parasites, ranking second amongst widespread parasitic diseases in subsaharan africa 1. The kato technique also called the katokatz technique is a laboratory method for preparing human stool samples prior to searching for parasite eggs. Comparison of the katokatz thick smear and mcmaster egg. A section of the stool sample was passed through a 250.
The kk method proved to be most sensitive in six groups with different egg counts. Later multiply by the appropriate number see inletinformation of the katoset to give the number of the eggs per gram faeces. A list of file names included in the cd or diskettes, with a simple description of the content of each file. The katokatz technique is recommended for the diagnosis of helminth infections in epidemiological surveys, drug efficacy studies and monitoring of control interventions. The katokatz method is widely used for diagnosing helminth infections in epidemiological surveys, but is known to have a low sensitivity. Comparison of the thick smear and katokatz techniques for diagnosis of intestinal helminth infections. Who has recommended kato katz technique in areas with moderate to high transmission rates of soil transmitted helminths i. High prevalence of ascariasis on two coral atolls in the.
The influence of sampling effort and the performance of. Nevertheless, we concluded that the kato katz method, when used with the thick smear, would be table 2 results of thick smear and kato katz analysis of 258 stool samples from public school children in salinas da margarida county, bahia. Nevertheless, we concluded that the katokatz method, when used with the thick smear, would be table 2 results of thick smear and katokatz analysis of 258 stool samples from public school children in salinas da margarida county, bahia. Template, stainless steel, plastic, or cardboard fig. Get a printable copy pdf file of the complete article 63k, or click on a page image below. This draft guidance, once finalized, will represent the food and drug administrations fdas. About 500 million people of the world are infected by it. Assessing stool quantities generated by three specific katokatz. In addition, for field surveys and investigational purposes, the egg output can be quantified by using the katokatz technique 20 to 50 mg of fecal material. In the case of schistosoma mansoni, statistical methods have been developed to compensate for the poor sensitivity, but the same is not true of any other helminth parasite, or infections with multiplehelminth species. Th e kato katz technique and auramine stain did not recover any other protozoan spe.
The kato katz technique is widely used in subsaharan africa for the diagnosis of schistosoma mansoni and soiltransmitted helminths. Nine hundred kato katz thick smear preparations were done. Diagnostic performance of a single and duplicate katokatz, miniflotac, fecpakg2 and qpcr for the detection and quantification of soiltransmitted helminths in three endemic countries. Coproparasitological diagnosis is still a challenge in management of helminth. Direct parasitological tests, such as the kato katz thick smear technique kato katz or kk, are the earliest diagnosis used for identification of schistosomiasis and are still widely applied nowadays 11. Quality control in the diagnosis of trichuris trichiura and ascaris lumbricoides using the katokatz technique. Aug 14, 2010 the kato katz technique is widely used for the diagnosis of soiltransmitted helminthiasis in epidemiological surveys and is believed to be an inexpensive method. Development of a laboratorial platform for diagnosis of. Quality control of the slides by katokatz method for the. All of them were detected by katokatz followed by the fec 70% and direct smear 32. We compared the accuracy of the katokatz method and etherconcentration technique for the diagnosis of soiltransmitted helminth. Quality control in the diagnosis of trichuris trichiura.
Diagnosis of intestinal parasites through examination of fresh faecal samples is hampered by its unpleasantness and the urgent need to detect all parasitic forms. Considering katokatz technique as the reference, there were 97. All of them were detected by kato katz followed by the fec 70% and direct smear 32. Diagnostic performance of a single and duplicate kato katz, miniflotac, fecpakg2 and qpcr for the detection and quantification of soiltransmitted helminths in three endemic countries. The katokatz technique and auramine stain did not recover any other protozoan species, which were all partly recovered by trichrome stain, direct smear and fec methods. Estimating the sensitivity and specificity of katokatz stool. Templates of different sizes have been produced in different countries. Considering kato katz technique as the reference, there were 97.
The cellophane thick smear kato or katokatz method and formalinether concentration fe techniques are two such modalities commonly used for its diagnosis. For a single katokatz, the clinical sensitivity equaled 71. Microscopic identification of whipworm eggs in feces is evidence of infection. Comparative study of the accuracy of different techniques for. Patients should be excluded from enrollment if they have severe complications due to worm infestations, including chronic dysentery, significant abdominal pain, abdominal.
The kato katz technique was the most sensitive, due to the higher quantity of stool examined sensitivity threshold 24 epg compared with the mcmaster technique sensitivity threshold 50 epg. The katokatz technique is still the method of choice for detection of sth infection in studies conducted in rural environments with poor infrastructure. Helmtec kit kato katz method for diagnosis and control of helminthiasis, 500 tests per kit, each kit containing. An accurate diagnosis of soiltransmitted helminthiasis is important for individual patient management, for drug efficacy evaluation and for monitoring control programmes. Diagnostic accuracy of katokatz and flotac for assessing anthelmintic drug efficacy, plos neglected tropical. The katokatz technique is widely used in subsaharan africa for the diagnosis of schistosoma mansoni and soiltransmitted helminths. The data indicates that sensitivity of the methods decreased after administration of drugs, but this is expected as fecs drop after treatment. Comparative cost assessment of the katokatz and flotac. In this paper, we compared the standard katokatz kk technique with a traditional fixation. For a double katokatz, the increase in sensitivity was not significant a. The case report form was included in the appendix appendix 3 summary of changes of statistical analysis.
Ninety percent of the infected population live in subsaharan africa. We assessed the comparability of the average amount of faeces generated by three katokatz templates included in test kits from two different providers. Comparison of the thick smear and kato katz techniques for diagnosis of intestinal helminth infections. Table 1 shows that the total number of helminthic infections was 40. An accurate diagnosis is important in order to identify individuals and communities in need of intervention, and for monitoring drug efficacy and potential emergence of resistance. Comparative study of the accuracy of different techniques. Fecal examination is the standard diagnostic method to diagnose most parasitic infections of the gastrointestinal tract, which include clonorchis sinensis infection. A manual of the katokatz technique was added in the appendix appendix 2. The kato katz technique is recommended for the diagnosis of helminth infections in epidemiological surveys, drug efficacy studies and monitoring of control interventions. Nine hundred katokatz thick smear preparations were done. Comparison between merthiolateiodineformalin and kato. Introduction to diagnostic medical parasitology home.
The katokatz technique is recommended by who for the diagnosis and quantification of schistosoma mansoni, other humanpathogenic schistosoma species e. The katokatz technique is the most widely used diagnostic method in. The influence of sampling effort and the performance of the. Kato katz kits contain a roll of cellophane that is cut into small pieces and soaked in.
Thick smear katokatz positive negative sensitivity specificity kappa index. Trichuris trichiura, also known as whipworm, is an intestinal nematode, that inhabit in the cecum. Katokatz technique, cellophane faecal thick smear a small amount of faecal material was placed on newspaper or scrap paper and a piece of nylon screen was pressed on top so that some of the faeces sieved through the screen and accumulated on top. However, detailed analyses of quality control, including falsepositive and faecal egg count fec. In cases of extremely light infection fe was found to be more sensitive than kk. Pdf diagnostic performance of a single and duplicate. The katokatz technique is recommended for the diagnosis of helminth.
The hoffman technique hh is based on spontaneous sedimentation, and it is effective because embryonated s. Since the katokatz technique lacks sensitivity for the diagnosis of lowintensity infections, we recommend the examination of multiple stool samples and combining the katokatz method with more sensitive diagnostic methods such as the miniflotac for sths or the pointofcare circulating cathodic antigen poccca urine cassette test for s. A single flotac is more sensitive than triplicate kato. Katokatz was performed following who recommendation. This study compared the effectiveness of the communitywide treatment and schoolbased treatment approaches in the control of schistosoma mansoni infections in villages with.
Because the severity of symptoms depend on the worm burden, quantification of the latter e. Pdf the katokatz technique is the most widely used diagnostic method in epidemiologic surveys and drug efficacy trials pertaining to. The ratio of the seroprevalence to the eggpositive. However, this technique has shown a lower sensitivity in individuals with a low parasite load, in areas of low endemicity, and receiving a particular therapy 44,45, which compromises the. The kato katz kk technique is most commonly used for detecting s. Pdf diagnostic performance of a single and duplicate kato. Soiltransmitted helminth infections are a major public health problem. Kato katz was performed following who recommendation. It has in the past been used for other helminth eggs as well. Comparison of the thick smear and katokatz techniques. Pdf comparison of the thick smear and katokatz techniques. For a single kato katz, the clinical sensitivity equaled 71.
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