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K E Mott

Publications and source records attributed to K E Mott.

At least 37 records · Page 2Linked to original sources
PubMed1987

Collaborative study on antigens for immunodiagnosis of Schistosoma japonicum infection.

Six research laboratories in Australia, Japan, the Philippines and the USA participated in a collaborative evaluation of immunodiagnostic tests for Schistosoma japonicum infections. The serum bank consisted of 385 well-documented sera from Brazil, Kenya, Philippines, Republic of Korea and Europe. Twelve S. japonicum antigen/test system combinations were evaluated.Crude S. japonicum egg antigens showed the highest sensitivity and specificity. The defined or characterized antigens showed no advantage over the crude antigens. Quantitative seroreactivity of all S. japonicum antigens showed a positive correlation with faecal egg counts (log x + 1) in all age groups. The performance of the circumoval precipitin test was satisfactory within the same laboratory but with differences in the results between laboratories. A monoclonal antibody used in a competitive radioimmunoassay test system performed as well as the crude egg antigens.The high sensitivity of crude S. japonicum antigens now permits further evaluation for wide-scale use in public health laboratories of endemic areas to support control efforts.

Antigens, Helminth↗
PubMed1986

Manson's schistosomiasis in Brazil: 11-year evaluation of successful disease control with oxamniquine.

This prospective study has shown that oxamniquine treatment controlled endemic schistosomiasis mansoni in a defined rural population in Castro Alves, north-east Brazil. Data before and after treatment spanning 11 years were collected for a cohort of 191 residents. Before treatment (1974-77), the cohort was heavily infected and the prevalence of associated hepatomegaly (greater than 86%) and splenomegaly (greater than 17%) was stable. The cohort was treated when oxamniquine became available in 1977; during the next 8 years, over 80% received further treatments from the Brazilian programme for the control of schistosomiasis. With treatment, the incidence of splenomegaly fell (10% to 2%) and the splenomegaly regression rate increased (43% to 91%). Declining disease rates were coincident with substantial falls in the prevalence and intensity of Schistosoma mansoni infections. The final prevalence rates for hepatomegaly (31%) and splenomegaly (3%) in Castro Alves approached the corresponding rates of 10% and 1% in a comparable uninfected control population.

Adolescent↗
PubMed1986

An outbreak of Chagas' disease in southwestern Bahia, Brazil.

An outbreak of 20 cases of acute Chagas' disease followed the movement of Triatoma infestans into the county of Riacho de Santana, Bahia, Brazil. The outbreak was unusual in that the majority of cases occurred in adults. Vector control measures were implemented. Three years after the outbreak, a rural community was examined to determine the extent of human infection and disease due to Trypanosoma cruzi. Ninety of 440 residents (20.5%) had serologic evidence of infection, but rates of electrocardiographic (EKG) abnormalities were low. Comparison of age-specific rates of seropositivity and EKG abnormalities with rates from areas with endemic Chagas' disease supported the hypothesis of a recent epidemic. Control measures appear to have interrupted transmission in the region.

Adult↗
PubMed1985

Three-year prospective study of the evolution of Manson's schistosomiasis in north-east Brazil.

A cross-sectional study of morbidity associated with Schistosoma mansoni infection in an area in North-East Brazil where the disease is endemic was carried out in 1974. The survey was repeated in 1977, before mass treatment with oxamniquine, providing a cohort of 210 individuals who had both examinations. The high prevalence of hepatomegaly (over 80%) and of splenomegaly (over 15%) contrasted with rates of 10% and 1%, respectively, in a non-endemic area. Over the 3-year period hepatomegaly spontaneously regressed in 13% of patients, and splenomegaly regressed in 56%, a phenomenon most common in older individuals with light infections. Those with heavy infections--ie, 500 or more eggs per g faeces, had an excess risk of splenomegaly of 19.6% and, of its persistence, of 61.5%. Thus, intensity of infection was a critical factor in liver and spleen involvement, and programmes of chemotherapy that reduce infection should mitigate the risk of schistosomal morbidity.

Adolescent↗
PubMed1985

Effect of praziquantel on hematuria and proteinuria in urinary schistosomiasis.

In five settlements on Lake Volta, Ghana, 230 persons infected with S. haematobium were treated with either 30 or 40 mg/kg of praziquantel. Both treatment regimes gave similar overall cure rates (60%) and reduction in geometric mean egg counts (92%) at a six-month follow-up. In this highly endemic area, 32% of the initial urine specimens were visibly bloody and only 4% remained bloody after treatment. Geometric mean egg counts of visibly bloody urine specimens were two to six times higher than normal appearing urine specimens. In children under 15 years of age, gross hematuria was reduced by 91% and hematuria as detected by reagent strips was reduced by 77% after treatment with praziquantel. Among adults, gross hematuria was reduced by 76% and hematuria as detected by reagent strips was reduced by 68%. Reduction was observed in 74% of all persons with 100 mg of protein/100 ml of urine or more prior to treatment. The cure rate with praziquantel was only 36.1% in children who had visibly bloody urine specimens associated with high geometric mean egg counts prior to treatment. The lowest cure rate (15.4%) was observed in persons with persistent hematuria and proteinuria after treatment although the geometric mean urinary egg count was reduced 84%. In infected individuals without hematuria or proteinuria prior to treatment, the cure rate was 96%. This study demonstrated that praziquantel reduced clinical signs due to S. haematobium infection as well as achieved a high cure rate and/or reduction of egg excretion. Conversely, individuals with clinical signs of hematuria and proteinuria had a lower cure rate with praziquantel than individuals without clinical signs.

Adolescent↗
PubMed1985

Evaluation of reagent strips in urine tests for detection of Schistosoma haematobium infection: a comparative study in Ghana and Zambia.

The presence of haematuria and proteinuria, detected by reagent strips, was compared with Schistosoma haematobium egg counts in the urines of human subjects from two epidemiologically distinct areas in Ghana and Zambia. In children and adults in both areas, the individual or combined semiquantitative levels of proteinuria and haematuria were related directly to increasing urinary egg counts. In both areas the presence of blood in the urine was highly specific (greater than 85%) and sensitive, being positive in 97% of urine specimens with more than 64 eggs per 5-ml sample of urine. The sensitivity of the protein indicator was also high, but its specificity was less than the blood indicator. The specificity of combined proteinuria and haematuria was higher than either alone; on the other hand, the sensitivity was lower than either alone. At each level of proteinuria and haematuria, the geometric mean urinary egg count was higher in Ghana than in Zambia. This study confirms the necessity to evaluate indirect diagnostic techniques in each endemic country, in order to establish criteria for their interpretation, before wide-scale use.

Adolescent↗
PubMed1985

Indirect screening for Schistosoma haematobium infection: a comparative study in Ghana and Zambia.

Four indirect approaches, based on inquiry into a past history of haematuria, visual inspection for blood in the urine specimens, and the use of reagent strips to detect haematuria and proteinuria, were evaluated to identify persons with Schistosoma haematobium infection. These approaches were applied individually and in three different screening sequences on two populations in Ghana and Zambia in order to identify infected children and adults for subsequent treatment in both areas. Detection of haematuria using reagent strips was the single approach with the highest sensitivity and specificity. The observation of gross haematuria (bloody urine), followed by detection of blood by reagent strips, identified 87% of infected children in both areas. This screening sequence showed the highest combined sensitivity and specificity in the identification of infected children as well as adults for treatment in both areas. Differences in the results between the two countries are discussed. This study emphasizes the need for evaluation of indirect screening procedures for the diagnosis of S. haematobium infection in each endemic area so as to establish criteria for their interpretation, prior to large-scale field application.

Adolescent↗
PubMed1984

Diagnostic tools for Schistosoma japonicum in control programmes.

Parasitological diagnostic techniques for control programmes should be inexpensive, quantitative and highly reliable. For parasitological diagnosis of Schistosoma japonicum infection in the field, the merthiolate-iodine-formaldehyde concentration (MIFC) technique has been widely used. This technique requires expensive laboratory equipment, including a centrifuge, its sensitivity is limited and the results are not reproducible quantitatively. The cellophane smear technique (Kato) is simple, reproducible and has been adapted as a quantitative measure of S. japonicum infection. The miracidial hatching technique is simple and highly sensitive but has not been well standardized for quantitative measurements. Ideally, immunodiagnostic tests for use in control programmes should be at least as sensitive and slightly less specific than the current parasitological techniques to assure detection of most infected persons. Recent evaluations of S. japonicum egg and adult antigens in various immunoassay systems indicate that immunodiagnosis may play an important role in the monitoring and surveillance phase of schistosomiasis control.

Antigens, Helminth↗
PubMed1983

Morbidity in schistosomiasis japonica in relation to intensity of infection. A study of two rural brigades in Anhui Province, China.

Schistosomiasis japonica remains endemic in several provinces south of the Yangtze River in China because of relatively sparse populations of human beings and dense populations of snails. We studied two brigades in a rural commune in Gui-chi County, Anhui Province, to determine the prevalence, intensity, and morbidity associated with this infection before concerted control efforts were instituted. Quantitative fecal examinations, histories, and physical examinations relevant to schistosomiasis japonica were performed in 96 per cent of the available population 2 to 65 years of age. The prevalence was 26.3 per cent in Brigade A (778 persons) and 14.4 per cent in Brigade B (1532 persons). Clinical symptoms and signs were compared among uninfected persons and persons at three levels of infection as determined by fecal egg output. Some increased weakness was seen only at the heaviest levels of infection; abdominal pain was not an important symptom. Hepatomegaly was somewhat more frequent in moderate and heavy infections, but splenomegaly was rare and unrelated to intensity of infection. Neither stool consistency nor occult blood was related to the presence or intensity of infection. Approximately 50 per cent of the population had been treated for schistosomiasis japonica, 25 per cent repeatedly.

Adolescent↗
PubMed1983

Relation between intensity of Schistosoma haematobium infection and clinical haematuria and proteinuria.

In an endemic area on Lake Volta, Ghana, urinary blood and protein levels as determined by chemical reagent strips in persons infected with Schistosoma haematobium, particularly in children aged between 5 and 14, correlated positively with urinary egg counts. Geometric mean S haematobium egg counts were 10 or more times higher in urine specimens with at least 10 mg/dl of protein and detectable haematuria than in those without detectable blood or protein. Chemical reagent strips were both specific and sensitive for detection of urinary blood associated with S haematobium infection. This simple technique could be useful for screening entire populations in which urinary schistosomiasis is endemic so that heavily infected persons needing specific treatment can be identified.

Adolescent↗
PubMed1983

Relationship of electrocardiographic abnormalities and seropositivity to Trypanosoma cruzi within a rural community in northeast Brazil.

The relationship of infection with Trypanosoma cruzi to ECG abnormalities was studied in a defined population in rural Bahia, Brazil. Of 644 individuals 10 years of age or older who had complement fixation tests for antibodies to T. cruzi and ECGs, 53.7% were seropositive. ECG abnormalities were more common in seropositive individuals than in seronegative individuals, and more common in men than in women. The peak prevalence rate of abnormal ECGs occurred among seropositive individuals between 25 and 44 years of age; in this age group ECG abnormalities occurred 9.6 times more frequently among seropositive individuals than among seronegative individuals. The most common abnormalities were ventricular conduction defects, and right bundle branch block with or without fascicular block occurred in 10.7% of the infected population. PR intervals were longer in seropositive individuals than in seronegative individuals. Ventricular extrasystoles were slightly more common in seropositive individuals. A declining prevalence rate of abnormal ECGs among older seropositive individuals suggested selective mortality due to Chagas' heart disease.

Adolescent↗
PubMed1982

A three-year follow-up study of infection with Trypanosoma cruzi and electrocardiographic abnormalities in a rural community in northeast Brazil.

The relationship between parasitemia, seroreactivity to Trypanosoma cruzi, and electrocardiographic abnormalities was studied in 115 individuals from a rural community in northeast Brazil where Chagas' disease is endemic. Vector control measures were introduced, and after 3 years 106 of the original participants were located and re-examined. Serum antibodies to T. cruzi were measured by complement fixation and indirect fluorescent antibody tests and parasitemia by xenodiagnosis and blood cultures. On both examinations more seropositive children than seropositive adults showed parasitemia, and parasitemia was more likely to persist over the 3-year period in younger individuals. Electrocardiographic (ECG) abnormalities were seen more frequently in seropositive individuals without parasitemia. However, ECG abnormalities, as expected, were more prevalent in older individuals and therefore no specific inverse relationship between ECG findings and parasitemia could be shown. The decreased prevalence of infection noted in younger individuals following the introduction of vector control measures indicates that this approach limited transmission.

Adolescent↗
PubMed1982

Collaborative study on antigens for immunodiagnosis of schistosomiasis.

Eight research laboratories in Europe and the United States of America were selected on the basis of having published data on Schistosoma mansoni and S. japonicum antigens to participate in a study of various antigen/test combinations for immunodiagnosis of schistosomiasis. The serum bank consisted of 395 well documented sera from four endemic areas in Brazil (2 areas), Kenya, and the Philippines. Altogether, 21 S. mansoni and four S. japonicum antigen and immunoassay combinations were evaluated.S. mansoni egg antigens yielded a higher combined sensitivity than adult worm antigens, irrespective of their purity, in active S. mansoni infections before and after specific treatment. Quantitative seroreactivity of characterized S. mansoni egg antigens showed good correlation with faecal egg counts in the 5-14 year age group. No correlation between morbidity related to S. mansoni and seroreactivity was observed in any test system.Three S. japonicum egg antigens showed high sensitivity and specificity in relation to the presence or absence of eggs in the stool. The quantitative seroreactivity of the characterized S. japonicum egg antigens correlated directly with the intensity of S. japonicum infection in all age groups.The enzyme-linked immunosorbent assay (ELISA), using several different procedures, performed well with the antigens used in the study. The indium slide immunoassay (ISI), a simple qualitative visual test system using an S. mansoni egg antigen, demonstrated a high degree of sensitivity and specificity.The results did not indicate the superiority of any particular immunodiagnostic method for detecting antischistosome antibodies. This collaborative study is considered a first step towards developing and standardizing antigens for immunodiagnosis of schistosomiasis.

Adolescent↗
PubMed1982

Field studies of a reusable polyamide filter for detection of Schistosoma haematobium eggs by urine filtration.

A reusable monofilament polyamide (Nytrel) filter and ninhydrin stained paper filter were compared in syringe filtration of urine to detect Schistosoma haematobium eggs in the urine under field conditions. The sensitivity of the technique using the Nytrel filter was similar to that of ninhydrin stained paper filters. The quantitative geometric mean S. haematobium egg counts obtained with the Nytrel filter were similar to those obtained with the paper filter.

Filtration↗