Search PubMed⌕ Search

Biomedical subjects

M H Merson

Publications and source records attributed to M H Merson.

At least 73 records · Page 4Linked to original sources
PubMed1977

An evaluation of penicillin prophylaxis during an outbreak of foodborne streptococcal pharyngitis.

Between August 16 and 21, 1974, an outbreak of beta-hemolytic group A M-9 T-9 streptococcal pharyngitis affected 49% of a randomly selected group of inmates at a jail in southern Florida. Food-specific attack rates incriminated improperly stored egg salad served at lunch on August 16 as the vehicle of transmission. By August 20, 290 symptomatic inmates had been placed on penicillin or erythromycin; on that day fewer than 5% of throat cultures from 400 allegedly non-penicillin-allergic largely asymptomatic inmates, cultured just before penicillin prophylaxis, were positive for the epidemic strain. At the time prophylaxis was given, secondary transmission had accounted for only 3% of cases. No non-suppurative sequelae were observed but 5% of inmates who received penicillin prophylaxis experienced an adverse reaction to the drug. Although widespread penicillin prophylaxis during outbreaks of group A beta-hemolytic streptococcal pharyngitis will likely prevent transmission of these organisms, prompt treatment of all symptomatic cases may be equally as effective in controlling adult institutional foodborne outbreaks of streptococcal pharyngitis and will likely minimize the number of adverse reactions to penicillin which may be seen.

Disease Outbreaks↗
PubMed1977

Type A botulism from commercially canned beef stew.

Two of three persons who ate lunch together became ill with symptoms characteristic of botulism. One died before botulism was suspected and before specimens could be collected for laboratory testing, but a serum specimen from the other patient, who survived, yielded botulinal toxin, type A. The third person remained asymptomatic, but Clostridium botulinum type A was cultured from his stool. The three persons had shared two canned foods: home-canned green beans and commercially canned beef stew. The green beans were initially assumed to be the cause of the outbreak. However, the empty stew can was recovered from the garbage, and washings from the can yielded C botulinum, type A, and its toxin.

Aged↗
PubMed1977

Enzyme-linked immunosorbent assay for detection of Escherichia coli heat-labile enterotoxin.

The development of an enzyme-linked immunosorbent assay (ELISA) for the detection of heat-labile Escherichia coli enterotoxin is described. The assay, which is based on the immunological similarity between Vibrio cholerae toxin and heat-labile E. coli enterotoxin, is similar in design to a radioimmunoassay but utilizes enzyme-labeled rather than radioactive isotope-labeled reagents. The ELISA system is as sensitive as both radioimmunoassay and the y-1 adrenal cell assay for the detection of heat-labile E. coli enterotoxin but requires neither radioactive reagents nor tissue culture techniques. The ELISA is easy to perform and is adaptable for use in small laboratories.

Drug Stability↗
PubMed1977

A large outbreak of foodborne salmonellosis on the Navajo Nation Indian Reservation, epidemiology and secondary transmission.

In September 1974, the largest outbreak of foodborne salmonellosis ever reported to the Center for Disease Control--affecting an estimated 3,400 persons--occurred on the Navajo Nation Indian Reservation. The responsible agent was Salmonella newport and the vehicle of transmission was potato salad served to an estimated 11,000 persons at a free barbecue. The cooked ingredients of the potato salad had been stored for up to 16 hours at improper holding temperatures. The magnitude of the outbreak allowed us to study secondary transmission by calculating the rates of diarrheal illness during the 2 weeks following the outbreak in persons who did not attend the barbecue and by examining the results of stool cultures obtained after the outbreak. We found no secondary transmission. We conclude that a health official should monitor food preparation and service at large social gatherings and that person-to-person transmission of salmonellosis probably does not normally occur even in settings considered highly conductive to cross-infection.

Adolescent↗
PubMed1977

The characteristics and mortality of outpatient-acquired pneumonia.

One-hundred fifty-four cases of pneumonia occurring over a 6-month period were analyzed. Population characteristics, admission diagnoses, causative pathogens, frequency of associated illnesses, antibiotic usage and mortality were evaluated. Despite population characteristics known to predispose to a poor clinical outcome, the mortality was low, probably because of rapid institution of a single, appropriate antibiotic.

Adult↗
PubMed1976

Travelers' diarrhea in Mexico. A prospective study of physicians and family members attending a congress.

We conducted a prospective study of travelers' diarrhea on 73 physicians and 48 family members attending a medical congress in Mexico City, in October, 1974. Fecal and blood specimens were collected before, during and after their visit and examined for enteric bacterial pathogens, viruses and parasites. In 59 (49 per cent) participants travelers' diarrhea developed. Median duration of illness was five days. Onset occurred a median of six days after arrival. An etiologic agent was found in 63 per cent of ill participants. Enterotoxigenic Escherichia coli of different, non-"enteropathogenic" serotypes was the most common cause; other responsible pathogens included salmonellae, invasive Esch. coli., shigellae, Vibrio parahaemolyticus, Giardia lamblia and the human reovirus-like agent. Consumption of salads containing raw vegetables was associated with enterotoxigenic Esch. coli infection (P = 0.014). Travelers' diarrhea in Mexico is a syndrome caused by a variety of pathogens, the most common of which is enterotoxigenic Esch. col.

Diarrhea↗
PubMed1976

Diagnostic value of indirect hemagglutination in the seroepidemiology of Shigella infections.

To evaluate the usefulness of the indirect hemagglutination (IHA) test in the epidemiological investigation of shigellosis, single serum specimens were tested from 50 patients with Shigella dysenteriae 1 (Shiga bacillus) infections, 103 asymptomatic contacts of these cases, 267 adult and 100 student control, and serum specimens collected during two outbreaks caused by S. sonnei and one outbreak due to S. flexneri 6. In patients with S. dysenteriae 1, 74% demonstrated titers of greater than or equal to 1:40, with 50% showing titers of greater than or equal to 1:160, whereas in the controls 10.4% had titers of greater than or equal to 1:40 and only 0.3% had titers of greater than or equal to 1:160. IHA titers in serum specimens collected from patients with S. sonnei and S. flexneri 6 were too low to be considered diagnostic for individual patients, but were useful in analysis of group results. Groups of ill individuals yielded titers significantly higher than non-ill groups; however, titers from ill groups were usually less than 1:40. The IHA test for S. dysenteriae 1 antibodies serves as a valuable adjunct to the diagnosis of Shiga bacillus dysentery. In our laboratory, an IHA titer of 1:40 or 1:80 is a "borderline positive." Shiga bacillus dysentery is strongly indicated when IHA titers are greater than or equal to 1:60.

Adult↗
PubMed1976

Laboratory investigation of diarrhea in travelers to Mexico: evaluation of methods for detecting enterotoxigenic Echerichia coli.

A laboratory investigation was conducted on cultures collected from travelers before, during, and after a trip to Mexico to characterize the etiology of traveler's diarrhea. Four laboratory methods for detecting enterotoxigenicity of Escherichia coli were evaluated: the infant mouse assay, the Chinese hamster ovary (CHO) cell assay, the Y1 adrenal cell assay, and the rabbit ileal loop. Although a number of common enteric pathogens were identified as a cause of traveler's diarrhea, including six serotypes of Salmonella, two serotypes of Shigella, Vibrio parahaemolyticus, Giardia lamblia, and Entamoeba histolytica, enterotoxigenic Escherichia coli was most commonly isolated. Strains were identified that produced only heat-labile enterotoxin (LT), only heat-stable enterotoxin (ST), or both LT and ST. The infant mouse assay yielded results falling into two distinct groups, providing a clear separation of positive and negative cultures. The CHO assay also formed two groups, with positive cultures producing 11% or more of the elongated cells. There was good agreement between the CHO and the Y1 adrenal cell assays for detection of LT. The adrenal cell system for detection of LT was more suitable than the CHO assay for processing large numbers of specimens because of the miniculture modification of this method utilized in this study. The infant mouse method was a simple and reliable method for detecting ST.

Animals↗
PubMed1975

A continuing common-source outbreak of botulism in a family.

In December, 1974, three cases of botulism occurred in a family; two were fatal. The first patient died after a 10-day illness without botulism being suspected. 4 days later, after a 2-day illness, the second patient was diagnosed as having botulism after a cardiorespiratory arrest; she died 3 days later. In the third patient, the only symptom was dysphagia. Clostridium botulinum type B was found in stool specimens from all three patients. Home-canned (bottled) mushrooms, which were found to contain C. botulinum type B and its toxin, were believed to be responsible for the outbreak; mushrooms were found at necropsy in the gastrointestinal tracts of both patients who died. Heat treatment of the mushrooms during canning had been inadequate.

Adult↗
PubMed1975

Diarrhoea associated with heat-stable enterotoxin-producing strains of Escherichia coli.

Five patients who developed acute watery diarrhoea while travelling in Mexico in October, 1974, were found to have enterotoxigenic Escherichia coli in their stool which produced heat-stable enterotoxin (S.T.) without producing heat-labile enterotoxin (L.T.). These S.T.-only E. coli, which have previously been described as causing diseases in animals, must now be regarded as pathogenic for humans as well.

Adult↗
PubMed1975

Gastrointestinal illness on passenger cruise ships.

Medical logs of 2,445 cruises taken by 38 vessels over a 20-month period beginning Jan 1, 1972, were reviewed. On 92% of the cruises, the recorded incidence of gastrointestinal illness was 1% or less; on 2% of cruises, it was 5% or greater. The actual incidence of gastrointestinal illness determined by a questionnaire survey of passengers sailing on nine cruises was found to be at least four times as high as that recorded in the medical logs. Although the cause of the illnesses was not known, there was evidence that transmission took place aboard ship. A survey of food-handling practices and water systems aboard selected ships demonstrated a significant potential for transmission of foodborne and waterborne disease.

Delivery of Health Care↗