Search PubMed⌕ Search

Biomedical subjects

D M Morens

Publications and source records attributed to D M Morens.

At least 55 records · Page 3Linked to original sources
PubMed1987

Dengue shock syndrome in an American traveler with primary dengue 3 infection.

A previously reported case of childhood dengue shock syndrome in an American traveler to India was investigated serologically. The original studies neither indicated the infecting serotype nor proved primary or secondary infection. However, BHK suspension PRNT of 6-year convalescent serum now indicates that the child had primary dengue type 3 infection. Dengue, dengue hemorrhagic fever, and dengue shock syndrome are potential hazards for American travelers and American residents of dengue-receptive areas.

Child↗
PubMed1986

Dengue in Puerto Rico, 1977: public health response to characterize and control an epidemic of multiple serotypes.

The largest and most extensive documented dengue epidemic in Puerto Rico struck an estimated 355,000 Puerto Rican residents from July-December 1977. The mixed epidemic of dengue types 2 and 3 coincided with a Caribbean pandemic of dengue type 1, first introduced into the western hemisphere in early 1977 and into Puerto Rico in the fall of that year. Health officials assembled a team to assess the epidemic and mounted a campaign to end it. Attempts to monitor the incidence and spread of dengue were confounded by simultaneous co-circulation of influenza virus, underscoring problems in formulating public health strategies dependent on nonspecific clinical and epidemiologic case criteria, and the need for rapid and reliable diagnostic capabilities. Despite co-circulation of multiple dengue serotypes, a risk factor associated with severe and fatal dengue hemorrhagic fever (DHF) in Southeast Asia, hospital and death certificate surveillance disclosed no cases of DHF in Puerto Rico. The epidemic serves as a reminder that when preventive measures are impossible or infeasible, developed countries with high living standards may be susceptible to large scale epidemics of infectious diseases.

Aedes↗
PubMed1985

Comparison of dengue virus plaque reduction neutralization by macro and "semi-micro' methods in LLC-MK2 cells.

A simplified "semi-micro' plaque reduction neutralization test (PRNT) for dengue antibody in LLC-MK2 cells in disposable tissue culture plates is described. The assay compares favorably with the standard PRNT in glass prescription bottles, with relative sensitivity and specificity both 100% at a 1:40 screening dilution by 70% plaque reduction criteria. The assay is easy to perform, economical of time, expense, and storage space, and is suitable for study of sera available in small volumes, such as those obtained on filter paper or by the capillary method. The LLC-MK2 semi-micro PRNT is an acceptable alternative to the standard PRNT, particularly in laboratories that use these cells routinely for other tissue culture work and for flavivirus vaccine development.

Antibodies, Viral↗
PubMed1985

Simplified plaque reduction neutralization assay for dengue viruses by semimicro methods in BHK-21 cells: comparison of the BHK suspension test with standard plaque reduction neutralization.

A newly modified semimicro plaque reduction neutralization test (PRNT) in BHK cells was compared with a standard PRNT in bottles with LLC-MK2 monolayers and with an LLC-MK2 PRNT adapted to semimicro methods. The BHK semimicro PRNT compared favorably in terms of sensitivity in detecting dengue antibody (96%), specificity at a screening dilution (95%), and ability to detect seroconversion to dengue viruses of three serotypes (93%). Disagreements between the BHK test and the LLC-MK2 tests were attributed to greater sensitivity of the BHK test in detecting dengue type 2 (DEN-2) antibody in acute-phase sera and to apparent low-level DEN-1/DEN-3 cross-reactions in some sera in all three tests. The BHK PRNT was easier, faster, and more economical than either of the LLC-MK2 tests. Many of the benefits of the BHK PRNT derive from the fact that cells are infected while still in suspension, at the time of cell splitting, hence the term "BHK suspension test."

Animals↗
PubMed1985

Acute hemorrhagic conjunctivitis caused by enterovirus type 70: an epidemic in American Samoa.

From December 1981 to February 1982, an estimated 22,000 cases of acute hemorrhagic conjunctivitis (AHC) caused by enterovirus type 70 (EV 70) occurred among Samoan and non-Samoan residents of American Samoa. The overall attack rate was estimated to be 68%. Samoans of all ages resident in traditional housing and of large family size were at greatest risk of acquiring AHC, while non-Samoan adults resident in western style housing were at lowest risk. Epidemiologic aspects of AHC acquisition were also different for the Samoan and non-Samoan communities; index cases in Samoan households were frequently young adults, whereas index cases in non-Samoan households were commonly school age children, suggesting a role for school transmission in non-Samoans only. In this outbreak, subclinical AHC was rare; of 50 asymptomatic members of affected households, only 3 had neutralizing antibody to EV 70 (all with titers of 1:10). Investigation documented the highly contagious nature of AHC caused by EV 70, and the ease with which epidemic transmission may develop under conditions of crowding and frequent interpersonal contact.

Acute Disease↗
PubMed1983

Acute hemorrhagic conjunctivitis Investigation of a large-scale community outbreak in Dade County, Florida.

An outbreak of acute hemorrhagic conjunctivitis (AHC) due to enterovirus type 70 occurred in Dade County, Florida, from September to December 1981. Younger age groups, members of larger households, and the poor were at significantly greater risk of acquiring AHC than others in the community. Schoolchildren were most likely to introduce AHC into the household. After exclusion of all affected children from school, there was a dramatic reduction in reported cases, with attack ratesups, members of larger households, and the poor were at significantly greater risk of acquiring AHC than others in the community. Schoolchildren were most likely to introduce AHC into the household. After exclusion of all affected children from school, there was a dramatic reduction in reported cases, with attack ratesups, members of larger households, and the poor were at significantly greater risk of acquiring AHC than others in the community. Schoolchildren were most likely to introduce AHC into the household. After exclusion of all affected children from school, there was a dramatic reduction in reported cases, with attack rates declining more rapidly for school-aged children than for other age groups. Although AHC spread readily among family members, a retrospective study of 124 affected households showed an association between lower attack rates and simple hygienic measures. Should outbreaks of AHC recur, measures to reduce transmission should include exclusion of affected schoolchildren and educating the public about hygienic precautions.

Acute Disease↗
PubMed1983

Kawasaki syndrome in the United States 1976 to 1980.

Review of 523 confirmed cases of Kawasaki syndrome reported to the Centers for Disease Control (CDC), during the period from July 1976 through December 1980, disclosed a previously unrecognized seasonal variation, with a peak incidence between February and May. A significantly higher incidence in black children, compared with white children, was also noted. Earlier reports of a higher incidence in children younger than 5 years of age, males, and children of Asian ancestry were confirmed. Frequently reported complications included joint involvement (27%) and cardiac abnormalities (22%); 1.2% of patients died. Four outbreaks (mean duration, 3.8 months) were investigated by the CDC, but no evidence of person-to-person transmission or a point source of exposure was found. These data suggest that some cases may be caused by an exogenous agent or toxin that is most prevalent in the late winter and spring. In addition, host, environmental, or other cofactors are likely to be important determinants of susceptibility.

Age Factors↗
PubMed1983

National case-control study of Kaposi's sarcoma and Pneumocystis carinii pneumonia in homosexual men: Part 2. Laboratory results.

The Centers for Disease Control conducted a case-control study to investigate an outbreak of Kaposi's sarcoma and Pneumocystis carinii pneumonia in homosexual men. The occurrence of these diseases was found to be associated with certain aspects of lifestyle, including a greater number of male sex partners per year, exposure to feces during sex, history of syphilis and non-B hepatitis, treatment for enteric parasites, and use of various illicit substances. Laboratory studies reflected both this lifestyle and the probable underlying cause of the Kaposi's sarcoma and P. carinii pneumonia--cellular immune deficiency. Patients were found to have lymphopenia, specifically a deficiency of the T-helper subpopulation, resulting in a reversal of the T-helper to T-suppressor ratio. Levels of IgG and IgA were increased. When compared with controls, patients were also found to have significantly higher titers of antibody to Epstein-Barr virus and cytomegalovirus, a higher prevalence of antibody to hepatitis A virus and Treponema pallidum, a lower prevalence of antibody to varicella zoster virus, and a higher frequency of isolation of cytomegalovirus.

Acquired Immunodeficiency Syndrome↗
PubMed1982

Kawasaki syndrome: association with the application of rug shampoo.

An outbreak of Kawasaki syndrome occurred in eastern Colorado during April and May, 1982. 48% of 23 cases had been exposed to the application of rug shampoo in the home in the 30 days before onset of disease, compared with 10% of 30 matched neighbourhood controls and 11% of 56 randomly chosen, matched community controls (p less than 0.01). The interval between rug shampooing and onset of disease was 16-25 days in 9 of 11 cases; 4 of the 9 had intervals of exactly 20 days. Although many brands of shampoo and three different methods of application were used, all but 1 of the cases had walked or crawled on the shampooed rugs within 2 h, the interval being significantly longer for those controls who had been exposed to the shampoo. 3 of 5 sporadic cases in Colorado who fell ill after November, 1981, had similar histories of exposure, as did 9 of 15 sporadic cases in eight other states who were contacted after the Colorado investigation. These findings suggest that exposure to the application of rug shampoo may be a risk factor for some cases of Kawasaki syndrome, although the mechanism remains to be determined.

Child, Preschool↗