Search PubMed⌕ Search

Biomedical subjects

M H Merson

Publications and source records attributed to M H Merson.

At least 55 records · Page 3Linked to original sources
PubMed1980

A two-year study of bacterial, viral, and parasitic agents associated with diarrhea in rural Bangladesh.

Enteric pathogens associated with diarrhea were studied for two years at a diarrhea treatment center in rural Bangladesh. Enterotoxigenic Escherichia coli (ETEC) was the most frequently identified pathogen for patients of all ages. Rotavirus and ETEC were isolated from approximately 50% and approximately 25%, respectively, of patients less than two years of age. A bacterial or viral pathogen was identified for 70% of these young children and for 56% of all patients with diarrhea. Most ETEC isolates were obtained in the hot dry months of March and April and the hot wet months of August and September. Rotavirus identification peaked in the cool dry months of December and January, but infected patients were found year-round. The low case-fatality rates for patients with watery diarrhea and substantial dehydration further document the usefulness of treating patients with diarrhea with either a glucose- or sucrose-base electrolyte solution such as those used in this treatment center.

Age Factors↗
PubMed1980

Detection of Escherichia coli enterotoxins in stools.

We determined whether enterotoxigenic Escherichia coli diarrhea could be diagnosed by direct examination of stools for heat-labile (LT) and heat-stable (ST) enterotoxins. The Y-1 adrenal cell and an enzyme-linked immunosorbent assay (ELISA) detected LT in 85 and 93%, respectively, of stool specimens obtained from adults with acute diarrhea from whom an LT- and ST-producing organism had been isolated. Furthermore, the ELISA assay detected LT in 8 of 35 stool specimens from which no LT-producing E. coli had been isolated. The infant mouse assay was utilized to detect ST in these stool specimens and was found to be an insensitive method, showing positive results in only 36% of the specimens from which an ST-producing organism was isolated. Further studies are warranted to determine the diagnostic value of direct detection of LT in stools, especially by the ELISA method.

Adolescent↗
PubMed1980

Oral rehydration therapy for treatment of rotavirus diarrhoea in a rural treatment centre in Bangladesh.

In November 1977, an enzyme-linked immunosorbent assay for detecting rotavirus antigen was introduced in the laboratory of a rural treatment centre in Bangladesh. During the next 40 days rotavirus without other pathogens was found in the stools of 216 (45%) of 480 children under age 5 years who visited the centre with a gastrointestinal illness. 188 (87%) of these children were treated with oral rehydration alone, using the solution currently recommended by the World Health Organisation, while 28 (13%) also required some intravenous rehydration; there were no deaths. Oral rehydration treatment was judged successful in 205 (95%) of the rotavirus patients and was not associated with any serious side effects. Oral rehydration treatment, with this solution, has been used extensively and successfully in the treatment of enterotoxin-mediated diarrhoea and can also safely be used for treating rotavirus diarrhoea in infants and young children.

Bangladesh↗
PubMed1980

Village-based distribution of oral rehydration therapy packets in Bangladesh.

The distribution of sucrose-electrolyte oral therapy packets (1 liter) by community-based workers in a rural Bangladesh population of 157,000 was evaluated. A similar population of 134,000 served as a comparison group. The locally-produced packets showed satisfactory chemical composition with a shelf-life of up to 3 months and a cost of U.S. $0.05. After 4 months the workers were distributing an average of 70 packets/1,000 population per month. Most patients used one packet for each episode of diarrhea; 13% of children used two packets, and 15% and 8% of adults used, respectively, two and three packets. The electrolyte composition of the oral fluids prepared by field workers and mothers showed substantial variation, but no hyperconcentrated solutions were noted. A comparison of the hospitalization rate from the two study areas suggested a 29% reduction in hospitalization for diarrhea during the 4 months of distribution.

Administration, Oral↗
PubMed1979

Disease caused by a marine Vibrio. Clinical characteristics and epidemiology.

We studied the clinical characteristics and epidemiology of disease associated with a rare, unnamed halophilic lactose-fermenting Vibrio species in 39 persons from whom the organism had been isolated. Two distinct clinical presentations were seen. In the first, the illness began with septicemia, often within 24 hours after raw oysters had been eaten; 18 of 24 such patients had pre-existing hepatic disease, and 11 of the 24 died. In the second, there was a wound infection after exposure to seawater or an injury incurred during the handling of crabs; none of these persons had pre-existing hepatic disease, and one of 15 died. Most cases (85 per cent) occurred during relatively warm months (May to October) in men (90 per cent) 40 or more years of age (95 per cent). This Vibrio species is a pathogen and should be considered in the differential diagnosis of septicemia with secondary skin lesions and of wound infections after exposure to seawater.

Adult↗
PubMed1979

Relationship between enterotoxin production and serotype in enterotoxigenic Escherichia coli.

We examined the relationship between serotype and enterotoxin production in 109 enterotoxigenic Escherichia coli strains isolated from 109 patients with severe cholera-like diarrhea in Dacca, Bangladesh. Of 69 strains producing both heat-labile and heat-stable toxins, 59 (86%) belonged to the one of four O serogroups, and 56 (81%) of these strains belonged to one of six O:K:H serotypes. In contrast, 34 strains producing only heat-stable toxin were distributed among 15 O serogroups, and six strains producing only heat-labile toxin were distributed among six O serogroups. Twelve strains producing heat-labile and heat-stable toxins and five strains producing heat-stable toxin were found which had the same serotype (O78:K-:H12) and biotype. It appears that at least in one geographic setting E. coli strains producing both heat-labile and heat-stable toxins are more restricted in their O groups and O:K:H serotypes than E. coli that produce only heat-stable toxin and that certain serobiotypes may commonly include strains which produce both toxin types.

Bacterial Toxins↗
PubMed1979

Comparison of four plating media for isolating Vibrio cholerae.

Two brands of thiosulfate citrate bile salts sucrose agar and Monsur taurocholate tellurite gelatin (TTG) agar were compared with two newly developed media, sucrose tellurite teepol agar and Vibrio parahaemolyticus agar for isolation and identification of Vibrio cholerae. The thiosulfate citrate bile salts sucrose and TTG agars were the best selective media, whereas sucrose tellurite teepol agar was the poorest. Both TTG and sucrose tellurite teepol agars were good for use in follow-up serological tests, whereas only TTG agar could be used for follow-up oxidase tests. In our opinion TTG agar has more advantages for cholera research laboratories routinely culturing large numbers of patients for cholera on a daily basis and where media needs can be accurately predicted. In contrast, in smaller clinical laboratories or in laboratories investigating epidemics, thiosulfate citrate bile salts sucrose agar is best because it is commercially available and easy to prepare and can be used to distinguish colonies of suspect V. cholerae from V. parahaemolyticus.

Bangladesh↗
PubMed1979

Use of colony pools for diagnosis of enterotoxigenic Escherichia coli diarrhea.

Diagnosis of enterotoxigenic Escherichia coli diarrhea was made in 109 adult males with an acute dehydrating cholera-like syndrome in Dacca, Bangladesh, by testing 10 colonies isolated from admission stool specimens for production of heat-labile and heat-stable toxins. Toxin testing of one colony yielded a diagnosis in 92% of the cases, testing of two colonies yielded a diagnosis in 95% of the cases, testing of a pool of 5 colonies yielded a diagnosis in 95% of the cases, and testing of a pool of 10 colonies yielded a diagnosis in 96% of the cases. From stool cultures obtained on subsequent days, toxin testing of individual colonies and pools revealed diminished efficacy of pooling with decreasing numbers of enterotoxin-positive isolates in the pool. To detect the presence of enterotoxigenic E. coli in stools, toxin testing of 5 individual isolates and a pool of 10 colonies was found to be almost as effective as the testing of 10 individual isolates.

Bacteriological Techniques↗
PubMed1978

Oral hydration rotavirus diarrhoea: a double blind comparison of sucrose with glucose electrolyte solution.

Of 57 male children, aged 5 months to 2 1/2 years with rotavirus diarrhoea, 28 were given oral therapy with sucrose electrolyte solution and 29 were given glucose electrolyte solution in a randomised double-blind trial. All were rehydrated and remained so on oral therapy alone. These patients were compared with 44 children, also with rotavirus, who were treated only with intravenous hydration. The oral therapy and intravenous therapy groups did not differ clinically in the rate of rehydration or the rate of purging. Vomiting did not prevent the giving of oral therapy during hospital admission. Bangladeshi children with rotavirus diarrhoea have a defect of carbohydrate digestion but this defect does not prevent the use of a sugar electrolyte solution for oral hydration.

Administration, Oral↗
PubMed1977

Coproexamination for botulinal toxin and clostridium botulinum. A new procedure for laboratory diagnosis of botulism.

Stool or serum specimens or both from 318 persons pertaining to 165 botulism investigations over a three-year period were examined. Botulinal toxin was detected in stools of 19 of 56 patients and in sera of 20 of 60 patients with clinical botulism; it was not detected in specimens from 246 persons with an illness other than botulism or well contacts of patients. Clostridium botulinum was identified in stools of 36 of 60 clinical botulism patients and in four of 27 asymptomatic contacts of patients with botulism victims, but not in stools of 65 persons not associated with confirmed botulism. When stool and serum samples were examined, confirmatory evidence was obtained for 72.9% of the botulism cases. Detection of botulinal toxin or C botulinum in the stool of a persons should be considered evidence supporting the clinical diagnosis of botulism.

Bacteriological Techniques↗
PubMed1977

Foodborne disease outbreaks of chemical etiology in the United States, 1970-1974.

In the United States between 1970 and 1974 there was an increase each year both in the absolute number of foodborne diseases outbreaks of chemical etiology reported to the Center for Disease Control and in the proportion of these outbreaks in the total reported foodborne disease outbreaks. Nearly half (48.9%) of these foodborne disease outbreaks of chemical origin were caused by toxic fish or shellfish. Of the rest, 16.5% were caused by poisonous mushrooms, 10.9% by heavy metal poisoning, 7.2% by excessive use in food of monosodium glutamate (the etiologic agent of Chinese Restaurant Syndrome) and 16.5% by miscellaneous chemicals. Practices that contributed to the occurrence of these outbreaks included the inadvertent selection for consumption of toxic fish, shellfish, or mushrooms, storage of fish at improper temperatures, storage of acidic liquids in metal containers, and addition of excessive amounts of monosodium glutamate to foods. Commercially-processed foods were responsible for outbreaks of scombroid fish poisoning, shellfish poisoning, and heavy metal poisoning. Because outbreaks of chemical etiology due to contaminated commercial products do occur, prompt recognition and reporting of outbreaks to public health personnel are essential so that epidemiologic investigations can be conducted and effective control measures promptly initiated.

Animals↗
PubMed1977

Cholera on Guam, 1974: epidemiologic findings and isolation of non-toxinogenic strains.

In August 1974, six cases of cholera occurred on Guam. The index case had severe diarrhea and metabolic acidosis and died from pneumonia on the ninth day of illness; the other five cases had only mild to moderate diarrhea. Fish caught in Agana Bay and home-preserved was found to be the vehicle most likely responsible for the cases. Vibrio cholerae, El Tor Ogawa, was isolated from two patients, the Guam sewerage system, and a river emptying into Agana Bay. V. cholerae, El Tor Inaba, was isolated from the sewerage system, three storm drains imptying into Agana Bay, and Agana Bay. The Ogawa and Inaba isolates differed in their sucrose fermentation and hemolysis reactions, phage type and ability to produce toxin. Although this was the first reported cholera outbreak on Guam, the isolation of differentV. cholerae strains suggested that multiple introductions of V. cholerae had occurred on the island.

Cholera↗