Showing papers by "Centers for Disease Control and Prevention published in 1987"

A ribosomal RNA gene probe differentiates member species of the Anopheles gambiae complex.

Abstract: A 0.59 kilobase DNA fragment cloned from an rDNA cistron of the mosquito Anopheles gambiae can be used as a probe to differentiate between A. gambiae, A. arabiensis, and A. melas, three morphologically identical sibling species in the A. gambiae complex which otherwise can be reliably distinguished only by polytene chromosome banding patterns. Although all are important (and often sympatric) African malaria vectors, their relative roles in malaria transmission have thus far been difficult to assess. The probe, an EcoRI-SalI fragment from the 3' end of the 28S beta coding region of the cistron, is present in all three species, but the species differ uniquely with respect to the location of an EcoRI site in the nontranscribed spacer (NTS) downstream of the fragment. We have routinely used the probe to identify A. gambiae complex mosquitoes to species on the basis of genomic DNA extracted from individual air dried specimens. A single mosquito abdomen provides more than sufficient DNA for the assay, and neither eggs nor a bloodmeal in the abdomen interfere with DNA yield. Moreover, the DNA extraction procedure does not degrade the bloodmeal IgG, so the residual protein pellet can be used to identify the mosquito bloodmeal source. Since the rDNA cistron organization as detected by the probe does not differ between male and female mosquitoes, the probe can be used for either sex. Preliminary experiments show that the probe is equally useful for mosquito larvae and pupae.

A Prospective Study of the Epidemiology and Ecology of Lassa Fever

Abstract: In studies of Lassa fever in Sierra Leone, the prevalence of human antibody to Lassa virus ranged from 8% to 52%. Mastomys natalensis, the reservoir of Lassa virus, constituted 50%-60% of the rodents captured in houses but only 10%-20% of those captured in surrounding agriculture and bush areas (chi 2 = 90.2, P less than 10(-6), df = 1), a finding suggesting that houses are the most-important location for transmission of Lassa virus. Viral infection of Mastomys from houses ranged from 0% to 80%. The incidence of seroconversions in susceptible persons ranged from 5% to 22% per year; the ratio of illness to infection ranged from 9% to 26%, and the proportion of febrile illness associated with seroconversion was 5%-14%. Eightfold rises in titer of antibody occurred in 1%-18% of the antibody-positive population, a result suggesting reinfection. We estimate the ratio of fatalities to infection to be 1%-2%, a rate lower than estimates based on hospitalized cases. The high incidence of Lassa fever makes it a major problem in West Africa.

Aedes albopictus in North America: probable introduction in used tires from northern Asia

Abstract: North American strains of Aedes albopictus, an Asian mosquito recently introduced into the Western Hemisphere, exhibit photoperiodic sensitivity and cold-hardiness characteristics similar to strains originating from temperate zone Asia. Trade statistics for used tire imports, the most likely mode of introduction, also indicate a north Asian origin. Aedes albopictus, an important vector of dengue and a potential vector of many other arboviral diseases, may therefore have the capability of infesting much of temperate North America.

Health and Economic Impacts of Antimicrobial Resistance

Abstract: For comparison of the impacts of infections due to antimicrobial-resistant bacteria with those of infections due to antimicrobial-susceptible strains of the same bacteria, data were evaluated from 175 published and unpublished reports of investigations of nosocomial and community-acquired infections with selected bacteria. The evaluation of outcomes of hospital-acquired infections with resistant organisms was often confounded by risk factors also associated with poor outcomes. Nevertheless, for both nosocomial and community-acquired infections, the mortality, the likelihood of hospitalization, and the length of hospital stay were usually at least twice as great for patients infected with drug-resistant strains as for those infected with drug-susceptible strains of the same bacteria. Poor outcomes could be attributed both to the expected effects of ineffective antimicrobial therapy and to the unexpected occurrence of drug-resistant infections complicated by prior antimicrobial therapy for other medical problems. Although the adverse economic and health effects of drug-resistant bacterial infections can only be roughly quantified, it is concluded that antimicrobial resistance is an important health problem and an economic burden to society.

Disseminated Vaccinia in a Military Recruit with Human Immunodeficiency Virus (HIV) Disease

Abstract: LIVE-VIRUS vaccines have been well recognized as a cause of severe complications when inadvertently administered to recipients with impaired immunologic function1 The acquired immunodeficiency syn

Treatment of Cryptococcal Meningitis with Combination Amphotericin B and Flucytosine for Four as Compared with Six Weeks

Abstract: One hundred ninety-four patients with cryptococcal meningitis were enrolled in a multicenter, prospective, randomized clinical trial to compare the efficacy and toxicity of four as compared with six weeks of combination amphotericin B and flucytosine therapy. Among 91 patients who met preestablished criteria for randomization, cure or improvement was noted in 75 percent of those treated for four weeks and in 85 percent of those treated for six weeks. The estimated relapse rate for the four-week regimen was higher--27 as compared with 16 percent--whereas the incidence of toxic effects for the two regimens was similar--44 as compared with 43 percent. Among 23 transplant recipients, 4 of 5 treated for four weeks relapsed, leading to the decision to treat the rest of the group for six weeks. Only 3 of the 18 treated for six weeks relapsed. In a third group of 80 patients, the protocol was not followed during the initial four weeks, and these patients were not randomized. Thirty-eight died or relapsed. Multifactorial analysis of pretreatment factors for all 194 patients identified three significant predictors (P less than 0.05) of a favorable response: headache as a symptom, normal mental status, and a cerebrospinal fluid white-cell count above 20 per cubic millimeter. These and other findings in this study are consistent with the view that the four-week regimen should be reserved for patients who have meningitis without neurologic complications, underlying disease, or immunosuppressive therapy; a pretreatment cerebrospinal fluid white-cell count above 20 per cubic millimeter and a serum cryptococcal antigen titer below 1:32; and at four weeks of therapy, a negative cerebrospinal fluid India ink preparation and serum and cerebrospinal fluid cryptococcal-antigen titers below 1:8. Patients who do not meet these criteria should receive at least six weeks of therapy.

A Case-Control Study of the Clinical Diagnosis and Course of Lassa Fever

Abstract: A prospective case-control study of Lassa fever was established in Sierra Leone to measure the frequency and case-fatality ratio of Lassa fever among febrile hospital admissions and to better delineate the clinical diagnosis and course of this disease. Lassa fever was responsible for 10%-16% of all adult medical admissions and for approximately 30% of adult deaths in the two hospitals studied. The case-fatality ratio for 441 hospitalized patients was 16.5%. We found the best predictor of Lassa fever to be the combination of fever, pharyngitis, retrosternal pain, and proteinuria (predictive value together, .81); of outcome, the best predictor was the combination of fever, sore throat, and vomiting (relative risk of death, 5.5). Complications included mucosal bleeding (17%), bilateral or unilateral eighth-nerve deafness (4%), and pleural (3%) or pericardial (2%) effusion. Lassa fever is endemic in this area and is a more-common cause of hospital admission and death than has previously been described; this disease must be considered when diagnosing febrile illness in West Africa.

The used tire trade: a mechanism for the worldwide dispersal of container breeding mosquitoes.

Abstract: Modern transportation methods have facilitated an extensive trade in used tires at the national and international level. The history and reasons for this trade are described. Comprehensive data on United States imports and United States, Japanese, and Korean exports of used tires for the period 1978-85 reveal an unprecedented potential for the worldwide dispersal of important vector mosquitoes such as Aedes albopictus and Ae. aegypti. Other articles of commerce with similar potential may await recognition.

Campylobacter enteritis at a university: transmission from eatingchicken and from cats

Abstract: Campylobacter jejuni is the most common enteric pathogen isolated from university and college students in the United States. During the fall and winter quarters of the 1983-1984 academic year, the authors conducted a case-control study at the University of Georgia, Athens, Georgia, to identify risk factors for C. jejuni enteritis. Students with diarrhea whose cultures yielded C. jejuni were compared with controls matched by age, sex, and residence. A total of 45 case-control pairs were interviewed about exposures during the week before the case's onset of illness. The infections occurred sporadically and were caused by a wide variety of C. jejuni serotypes. Three risk factors were identified: eating fully cooked chicken, eating chicken reported to be raw or undercooked, and contact with a cat or kitten. No case reported drinking raw milk. No significant association was found between illness and the places where chicken meals were prepared or the specific manner in which chicken was cooked. Chicken may be the principal vehicle of transmission for sporadic Campylobacter enteritis among college students.

Opportunistic diseases reported in AIDS patients: frequencies, associations, and trends.

Abstract: To look for associations and trends in the reported frequencies of particular opportunistic diseases in AIDS patients, we analyzed diseases in the 30,632 AIDS patients in the United States reported to the Centers for Disease Control (CDC) by 9 February 1987. Compared with all other AIDS patients, children were three times more likely to have cytomegalovirus disease, homosexual men were seven times more likely to have Kaposi's sarcoma, and Haitian-born patients were six, 14 and 13 times more likely to have toxoplasmosis, tuberculosis, and chronic enteric isosporiasis, respectively. The proportions of patients initially presenting with particular diseases have changed; from before 1983 to 1986, the proportion with Pneumocystis pneumonia climbed from 41.9 to 63.6% and the proportion with extrapulmonary cryptococcosis rose from 4.5 to 6.2%, while Kaposi's sarcoma fell from 30.9 to 14.2%, chronic herpes simplex declined from 4.2 to 2.1%, and toxoplasmosis of the brain dropped from 3.5 to 1.5%.

Dengue and dengue hemorrhagic fever in the Americas.

Abstract: There has been a constant increase in the incidence of dengue in the Americas over the past 15 years. This has been caused by increased frequency of epidemic activity in most countries, as a result of increased numbers of virus serotypes circulating in the region. The change in disease ecology has resulted in the emergence of dengue hemorrhagic fever/dengue shock syndrome (DHF/DSS) in the region, first with a major epidemic in Cuba, followed by increased occurrence of sporadic cases of DHF/DSS in many countries. The sequence of events in the Americas in the 1980's has been nearly identical to the pattern observed in Southeast Asia in the 1950's. Prospects for prevention of epidemic DHF/DSS in the American region, therefore, are not good. In the absence of Aedes aegypti eradication, the only hope for effective prevention and control is to develop more effective active surveillance for DHF/DSS and combine that with both emergency and community-based vector control programs.

The differentiated form of nasopharyngeal carcinoma contains Epstein-Barr virus DNA.

Abstract: Immunologic studies of Epstein-Barr virus (EBV) have implicated EBV in undifferentiated and partially differentiated, non-keratinizing nasopharyngeal carcinoma (NPC). Patients with the well-differentiated, keratinizing form of NPC have EBV serologic patterns similar to those of control populations. In addition, viral DNA has not been detected in the differentiated tumors using viral cRNA probes to DNA immobilized on filters. In this study we have tested for EBV DNA using recombinant DNA probes to Southern blots of DNA from 33 NPC specimens. The 24 undifferentiated and 4 partially differentiated specimens generally contained a relatively high number of EBV genome equivalents, while the 5 well-differentiated NPC all contained detectable EBV, but at low copy number. The viral DNA from one of the well-differentiated specimens was cloned into a cosmid vector. Five recombinant clones representing the fused viral termini were obtained, indicating the presence of episomal, intracellular DNA in the tumor. These findings indicate that all histologic subsets of NPC contain EBV DNA.

Massive Outbreak of Antimicrobial-Resistant Salmonellosis Traced to Pasteurized Milk

Abstract: Two waves of antimicrobial-resistantSalmonella typhimuriuminfections in Illinois totaling over 16000 culture-confirmed cases were traced to two brands of pasteurized 2% milk produced by a single dairy plant. Salmonellosis was associated with taking antimicrobials before onset of illness. Two surveys to determine the number of persons who were actually affected yielded estimates of 168791 and 197581 persons, making this the largest outbreak of salmonellosis ever identified in the United States. The epidemic strain was easily identified because it had a rare antimicrobial resistance pattern and a highly unusual plasmid profile; study of stored isolates showed it had caused clusters of salmonellosis during the previous ten months that may have been related to the same plant, suggesting that the strain had persisted in the plant and repeatedly contaminated milk after pasteurization. (JAMA1987;258:3269-3274)

Clinical Virology of Lassa Fever in Hospitalized Patients

Abstract: We measured levels of virus in sequential specimens from 137 patients with Lassa fever. The probability of fatal disease increased significantly with the level of viremia measured either on admission or during the course of illness. The odds ratio of death in patients with viremia greater than 10 TCID50/ml was 3.7 (90% confidence interval, 1.9-7.2). The same ratio in patients with viremia greater than 10 TCID50/ml and with levels of aspartate aminotransferase greater than or equal to 150 IU/liter was 21.5 (95% confidence interval, 5.2-99.0). Virus was found in throat cultures from 39% of viremic patients, compared with 14% of nonviremic patients (P less than .002); however, the level of virus was usually less than or equal to TCID50/ml. Fewer than 3% of patients were viruric during acute illness, and virus was isolated from three of three samples of cerebrospinal fluid. On admission, 53% of patients had IgG antibodies, and 67% had IgM antibodies. Recovery was not associated with the presence of either IgG or IgM. Virus was isolated from greater than 100 serum specimens that also contained high titers of IgG. Clinical Lassa fever was shown to be a disseminated systemic, primary viral infection, with an outcome highly associated with viremia but not with development of antibody.

Effect of immunization with a vaccinia-HIV env recombinant on HIV infection of chimpanzees.

Abstract: Acquired immunodeficiency syndrome (AIDS) is caused by human immunodeficiency virus (HIV) and is now recognized as a worldwide epidemic for which there is no cure or vaccine. Chimpanzees are the only other animals that can be infected by HIV, and therefore the chimpanzee-HIV model system is useful for testing potential HIV vaccines. However, with one exception, there have been no reports of clinical manifestations of AIDS in chimpanzees. We report here results of an HIV vaccine trial in which nine chimpanzees were first immunized with either a recombinant vaccinia virus expressing the envelope glycoproteins of HIV strain LAV-1 (v-env5) or a control recombinant vaccinia virus and were then challenged with a high or low dose of LAV-1. Although HIV-specific antibody and T-cell responses were elicited by immunization, virus was isolated from lymphocytes of all challenged chimpanzees, indicating that immunization did not prevent infection by HIV. Among the animals that received a higher dose of LAV-1, one of two control chimpanzees, but none of the four v-env5-immunized chimpanzees developed substantial and persistent lymphadenopathy.

Childhood upper respiratory tract infections: to what degree is incidence affected by day-care attendance?

Abstract: Risk factors for acute upper respiratory tract disease in childhood were evaluated in a population-based sample of the Atlanta metropolitan area. Mothers from 449 households containing 575 children less than 5 years of age were selected by random-digit dialing and questioned about upper respiratory tract infection and ear infection occurring in their children during the preceding 2 weeks. Household demographic and socioeconomic characteristics, maternal smoking history and child day-care attendance and breast-feeding information were also obtained. For children less than 5 years of age, the reported incidence of upper respiratory tract infection was 24%, and of ear infection, 6%. Controlling for the other variables measured, day-care attendance was associated with a significantly increased risk of both illnesses. For upper respiratory tract infection, increased risk was present for all children attending day care (P = .02, odds ratio = 1.6), whereas for ear infection, risk could be demonstrated only for full-time attendees (P = .005, odds ratio = 3.8). Maternal smoking was a second independent risk factor for a child's having upper respiratory tract infection (odds ratio = 1.7, P = .01). Thirty-one percent of all upper respiratory tract infection among day-care attendees and 66% of all ear infections among full-time day-care attendees were attributable to day-care attendance. Given the proportion of children in day care, 9% to 14% of the total burden of upper respiratory tract disease in this population was day care related.(ABSTRACT TRUNCATED AT 250 WORDS)

Development of a plaque assay for a cytopathic, rapidly replicating isolate of hepatitis A virus.

Abstract: Most hepatitis A virus (HAV) replication in cell culture has been reported to be nonlytic and relatively slow. A rapidly replicating isolate of strain HM-175 from persistently infected, serially passed cell cultures (pHM-175) was found to induce a cytopathic effect. This observation allowed the development of a classic plaque assay for pHM-175 in FRhK-4 cells. The plaques were neutralized by polyclonal and monoclonal antisera to HAV.

Synthetic peptide immunoassay distinguishes HIV type 1 and HIV type 2 infections

Abstract: Efforts to solve the epidemiologic puzzle of AIDS in Africa are complicated by the presence of multiple human retroviruses. Simple serologic tests that unambiguously distinguish among infections by these retroviruses are essential. To that end, a partially conserved immunoreactive epitope was identified in the transmembrane glycoproteins of human immunodeficiency viruses (HIV) types 1 and 2. Synthetic peptides derived from these conserved domains were used in sensitive and specific immunoassays that detect antibodies in sera from patients infected with HIV-1 or HIV-2. By making single amino acid substitutions in the HIV-1 peptide, it was possible to demonstrate HIV-1 strain-specific antibody responses to this epitope. Such custom-designed peptides synthesized from this domain are likely to detect newly discovered HIV types, define infection with specific HIV strains, and allow detection of group-common antibodies.

Are physicians advising smokers to quit? The patient's perspective.

Abstract: Physicians can play an important role in smoking cessation because they have frequent contact with smokers and because most smokers believe that a physician's advice is important in the decision to quit. Therefore, to determine smokers' perceptions of physician involvement in smoking cessation, we analyzed aggregate data from two random statewide surveys of 5875 Michigan adults. Of smokers who had seen a physician in the previous year, only 44% reported that they had ever been told to quit smoking by a physician. Young male smokers were the least likely (30%) to have been told to quit. Smokers who were hypertensive, obese, diabetic, sedentary, or users of oral contraceptives were no more likely to have been told to quit than smokers without these additional cardiovascular risks. Conversely, smokers who had survived a myocardial infarction or stroke were more likely to have been told to quit than smokers who had not suffered these events (73% vs 43%). Most smokers do not perceive physicians to be even minimally involved in their efforts to quit. Physicians need to increase their efforts in counseling smokers to quit before smoking-related diseases result, especially for smokers with additional risk factors for cardiovascular disease. ( JAMA 1987;257:1916-1919)

Q Fever: Current Concepts

Abstract: Persons with Q fever usually present with severe retrobulbar headache, a fever to 104 degrees F or higher with shaking chills, general malaise, myalgia, chest pain, and sometimes pneumonia and hepatitis. Cattle, sheep, goats, and ticks are the primary reservoirs of the etiologic agent, Coxiella burnetii. Humans are usually infected by inhaling infectious aerosols. Because C. burnetii can survive for long periods in the environment, it poses a continuing health hazard once it is disseminated. Q fever usually occurs sporadically, but large outbreaks are frequently observed throughout the world, particularly among abattoir workers and personnel working in research centers. Q fever endocarditis follows a chronic course and is frequently fatal. Tests for antibodies to C. burnetii are required for confirmation of the diagnosis. Tetracyclines remain the mainstay of treatment for acute Q fever, and tetracyclines in combination with other antibiotics have been advocated for patients with Q fever endocarditis. Vaccines for Q fever have been proven effective in clinical trials.

Toxic shock syndrome: A newly recognized complication of influenza and influenzalike illness

Abstract: Nine cases of severe hypotension or death compatible with toxic shock syndrome (TSS) as a complication of influenza and influenzalike illness were identified in Minnesota with onsets between Jan 2,1986, and Feb 23,1986, in which five of the patients died. During this time, an influenza outbreak was occurring in the state. Cultures of respiratory secretions were performed in eight patients;Staphylococcus aureuswas isolated from all of them. SevenS aureusisolates were available for determination of exotoxin production; five isolates produced toxic shock syndrome toxin-1, one produced enterotoxin B, and one produced both. Acute influenza B infection was confirmed in three of four patients for whom throat cultures or acute and convalescent serum samples were available. Two patients fulfilled the Centers for Disease Control—confirmed case definition for TSS. Four additional patients fulfilled the CDC criteria for a probable case of TSS, and TSS was a likely diagnosis in the remaining three patients. The initial presentation was suggestive of nonsuppurative tracheitis or viral pneumonia in eight patients. In the remaining patient, the initial clinical presentation was compatible with staphylococcal pneumonia. This report demonstrates that TSS can occur as a complication of influenza and influenzalike illness. (JAMA1987;257:1053-1058)

Acquired immunodeficiency syndrome in children: report of the Centers for Disease Control National Surveillance, 1982 to 1985.

Abstract: Since national surveillance for acquired immunodeficiency syndrome (AIDS) began in 1981, the Centers for Disease Control (CDC) has received reports of more than 20,000 cases of AIDS in the United States. As of December 31, 1985, 307 of these cases had been diagnosed in children younger than 13 years of age. The number of cases is increasing rapidly. The number of cases reported in 1985 more than doubled those reported in 1984. The major risk factors in children for acquiring infection with the causative agent, human immunodeficiency virus (HIV), were having a mother known to be infected and/or at increased risk for infection and receiving a transfusion of blood or blood products. Of the 307 children with AIDS, 73% were reported from one of four states: New York, New Jersey, Florida, and California. Most AIDS cases in children occur in black or Hispanic infants and toddlers. The estimated incubation period for AIDS in children has increased each surveillance year, with the longest incubation exceeding 7 years. The prognosis for children with AIDS is poor and infants less than 1 year of age have the shortest survival time following diagnosis. Continued national surveillance for AIDS is mandatory for establishing effective prevention programs to control the spread of the disease. The CDC encourages all health care personnel to report cases of AIDS to their public health departments.