Changes in tuberculosis epidemiology, United States, 1993-2017.

BACKGROUND: After 20 years of steady decline, the pace of decline of tuberculosis (TB) incidence in the United States has slowed.METHODS: Trends in TB incidence rates and case counts since 1993 were assessed using national US surveillance data. Patient characteristics reported during 2014-2017 were compared with those for 2010-2013.RESULTS: TB rates and case counts slowed to an annual decline of respectively 2.2% (95%CI -3.4 to -1.0) and 1.5% (95%CI -2.7 to -0.3) since 2012, with decreases among US-born persons and no change among non-US-born persons. Overall, persons with TB diagnosed during 2014-2017 were older, more likely to have combined pulmonary and extra-pulmonary disease than extra-pulmonary disease alone, more likely to be of non-White race, and less likely to have human immunodeficiency virus infection, or cavitary pulmonary disease. During 2014-2017, non-US-born persons with TB were more likely to have diabetes mellitus, while the US-born were more likely to have smear-positive TB and use non-injecting drugs.CONCLUSION: Changes in epidemiologic trends are likely to affect TB incidence in the coming decades. The Centers for Disease Control and Prevention has called for increased attention to TB prevention through the detection and treatment of latent tuberculous infection.

Estimating tuberculosis cases and their economic costs averted in the United States over the past two decades.

BACKGROUND: Following a concerted public health response to the resurgence of tuberculosis (TB) in the United States in the late 1980s, annual TB incidence decreased substantially. However, no estimates exist of the number and cost savings of TB cases averted. METHODS: TB cases averted in the United States during 1995-2014 were estimated: Scenario 1 used a static 1992 case rate; Scenario 2 applied the 1992 rate to foreign-born cases, and a pre-resurgence 5.1% annual decline to US-born cases; and a statistical model assessed human immunodeficiency virus and TB program indices. We applied the cost of illness to estimate the societal benefits (costs averted) in 2014 dollars. RESULTS: During 1992-2014, 368 184 incident TB cases were reported, and cases decreased by two thirds during that period. In the scenarios and statistical model, TB cases averted during 1995-2014 ranged from approximately 145 000 to 319 000. The societal benefits of averted TB cases ranged from US$3.1 to US$6.7 billion, excluding deaths, and from US$6.7 to US$14.5 billion, including deaths. CONCLUSIONS: Coordinated efforts in TB control and prevention in the United States yielded a remarkable number of TB cases averted and societal economic benefits. We illustrate the value of concerted action and targeted public health funding.

Preventing congenital toxoplasmosis.

SCOPE OF THE PROBLEM: Toxoplasmosis is caused by infection with the protozoan parasite Toxoplasma gondii. Acute infections in pregnant women can be transmitted to the fetus and cause severe illness (e.g., mental retardation, blindness, and epilepsy). An estimated 400-4,000 cases of congenital toxoplasmosis occur each year in the United States. Of the 750 deaths attributed to toxoplasmosis each year, 375 (50%) are believed to be caused by eating contaminated meat, making toxoplasmosis the third leading cause of foodborne deaths in this country. ETIOLOGIC FACTORS: Toxoplasma can be transmitted to humans by three principal routes: a) ingestion of raw or inadequately cooked infected meat; b) ingestion of oocysts, an environmentally resistant form of the organism that cats pass in their feces, with exposure of humans occurring through exposure to cat litter or soil (e.g., from gardening or unwashed fruits or vegetables); and c) a newly infected pregnant woman passing the infection to her unborn fetus. RECOMMENDATIONSFOR PREVENTION: Toxoplasma infection can be prevented in large part by a) cooking meat to a safe temperature (i.e., one sufficient to kill Toxoplasma); b) peeling or thoroughly washing fruits and vegetables before eating; c) cleaning cooking surfaces and utensils afterthey have contacted raw meat, poultry, seafood, or unwashed fruits or vegetables; d) pregnant women avoiding changing cat litter or, if no one else is available to change the cat litter, using gloves, then washing hands thoroughly; and e) not feeding raw or undercooked meat to cats and keeping cats inside to prevent acquisition of Toxoplasma by eating infected prey. RESEARCH AGENDA: Priorities for research were discussed at a national workshop sponsored by CDC in September 1998 and include a) improving estimates of the burden of toxoplasmosis, b) improving diagnostic tests to determine when a person becomes infected with Toxoplasma, and c) determining the applicability of national screening programs. CONCLUSION: Many cases of congenital toxoplasmosis can be prevented. Specific measures can be taken by women and their health-care providers to decrease the risk for infection during pregnancy and prevent severe illness in newborn infants.

Outbreak of parasitic gastroenteritis among travelers returning from Africa.

Eosinophilia and intestinal infections with a trematode parasite developed in 18 of the 20 American tourists who traveled to Kenya and Tanzania; the fact that the two other tourists also had eosinophilia suggested that they too had been infested. Because no adult flukes were recovered, a specific identification could not be made, but the eggs we observed resembled those of an Echinostoma. Several tour members had mild, nonspecific abdominal complaints, but ten had moderately severe abdominal cramps and loose or watery stools. Treatment with praziquantel was associated with rapid symptomatic improvement, and after treatment no parasitic eggs were recovered from patients' stools.

Prospective study of etiologic agents of community-acquired pneumonia in patients with HIV infection.

OBJECTIVES: To study prospectively HIV-positive patients admitted to the hospital because of pneumonia by extensive laboratory tests to determine specific microbiologic diagnoses and to establish the best clinical diagnosis after review of all available data by expert clinicians. METHODS: Patients admitted to one of two hospitals had extensive questionnaires completed and defined diagnostic tests performed on blood, sputum, urine and bronchoalveolar lavage specimens, when available. RESULTS: A total of 230 patients had a diagnosis of pneumonia verified. A definite or probable etiologic diagnosis was made in 155 (67%) of these patients. Pneumocystis carinii caused 35% of all cases of pneumonia. Twenty-seven percent of cases of pneumonia with a single etiology had a definite or probable bacterial etiology. 'Atypical agents' were distinctly uncommon. Few clinical or laboratory parameters could differentiate specific etiologies. CONCLUSIONS: P. carinii continues to be a common cause of pneumonia in these patients. The rarity of 'atypical agents' could simplify the empiric approach to therapy. Despite the use of extensive testing we did not find a definite etiology in a large number of cases.

Toxoplasmic encephalitis in HIV-infected persons: risk factors and trends. The Adult/Adolescent Spectrum of Disease Group.

OBJECTIVE: To evaluate the incidence of and risk factors for toxoplasmic encephalitis among HIV-infected persons. DESIGN: Medical facility-based prospective medical record reviews of consecutive patients. METHODS: We analysed data collected from January 1990 through August 1995 in more than 90 inpatient and outpatient medical facilities in nine US cities. Incidence was calculated as cases per 100 person-years and risk ratios (RR) for annual incidence were calculated using proportional hazards regression while controlling for city, sex, race, age, county of birth, HIV exposure mode, and prior prescription of trimethoprim-sulfamethoxazole (TMP-SMX). RESULTS: The incidence of TE was 4.0 cases per 100 person-years among persons with a CD4+ T-lymphocyte count of < 100 x 10(6)/l. In multivariate analysis, among the nine cities the annual incidence of toxoplasmosis was significantly lower only in Denver [RR, 0.3; 95% confidence interval (CI), 0.1-0.7; referent city, Seattle]. Persons prescribed TMP-SMX were half as likely to develop toxoplasmic encephalitis as those who were not (RR, 0.5; 95% CI, 0.4-0.7). Of the 4173 persons with AIDS (1987 Centers for Disease Control and Prevention definition) who died during the study period, 267 (6.4%) had toxoplasmic encephalitis in the course of HIV disease. CONCLUSIONS: Toxoplasmic encephalitis in HIV-infected persons varies by geographic area in the United States. TMP-SMX reduces the risk for toxoplasmic encephalitis.

Creatine kinase MB isoenzyme in the evaluation of myocardial infarction.

The measurement of serum CK-MB isoenzyme is a very sensitive and specific indication of myocardial injury since only myocardium has substantial amounts of CK-MB. Serum CK-MB levels are most helpful clinically when the total creatine kinase is nonspecifically elevated, as with intramuscular injections, cardiac catheterization, stroke, noncardiac surgery and electric cardioversion. Elevations of serum CK-MB occurring in Duchenne's muscular dystrophy and other neuromuscular disorders may be due to the presence of abnormal regenerative skeletal muscle fibers, which are known to contain large amounts of CK-MB isoenzyme. These examples emphasize that under normal, nonregenerative conditions, elevations of serum CK-MB are rare in the absence of myocardial injury.

Transient elevation of serum activity of MB isoenzyme of creatine phosphokinase in drivers involved in automobile accidents.

Drivers involved in automobile accidents were screened for the presence of occult cardiac injury without regard for apparent severity of the accident or injury. An electrocardiogram was recorded, and serum levels of total creatine phosphokinase and the MB isoenzyme of creatine phosphokinase (myocardial form) were measured as soon as possible after the accident and subsequently during admission (or on the following day in patients treated and discharged from the emergency room). Electrocardiographic abnormalities were observed in 18 of 82 patients but correlated poorly with other evidence of the severity or location of injury. Of the 22 drivers admitted to the hospital (for any cause), nine demonstrated significant early elevations of the activity of the MB isoenzyme of creatine phosphokinase. We conclude that blunt cardiac trauma is a clinical subtlety; to be found, it must be sought. The ECG is of limited value. Measurement of the serum activity of the MB isoenzyme of creatine phosphokinase early after injury would appear to offer the best evidence of cardiac trauma.

Comparison of active and passive case detection of cutaneous leishmaniasis in Guatemala.

To estimate the degree to which passive case detection underestimates the true incidence of cutaneous leishmaniasis in Guatemala, we compared data from the passive surveillance system of the Guatemalan Ministry of Health with a cross-sectional population-based survey of cutaneous leishmaniasis in Guatemala. Of the 2,938 persons interviewed, 143 (5%) reported having had cutaneous leishmaniasis at some time in the past, 37 (1.3%) reported the onset of infection in the 12 months before the survey, 31 (1.1%) had active infections, and 16 (0.5%) had parasitologically confirmed infections. Calculated on the basis of these reports and the estimated population of the endemic area, the total number of new cases in the leishmaniasis-endemic area in the 12 months before the survey was approximately 2,574; during the same 12 month period, Ministry of Health data based on passive surveillance listed 64 cases of cutaneous leishmaniasis. In Guatemala, incidence estimates based on passive surveillance may underestimate the occurrence of cutaneous leishmaniasis by as much as a factor of 40.

Cutaneous leishmaniasis in Guatemala: isoenzyme characterization of isolates from humans.

Leishmania organisms cultivated from cutaneous lesions of humans in Guatemala were characterized by cellulose acetate electrophoresis. Six isolates had electrophoretic enzyme patterns identical to World Health Organization reference strains of Leishmania braziliensis braziliensis, and 5 had patterns identical to reference strains of Leishmania mexicana mexicana.

Epidemiologic study of visceral leishmaniasis in Honduras, 1975-1983.

Between 1975 and 1983, 53 patients with parasitologically proven visceral leishmaniasis (VL) and 16 patients with suspected VL were diagnosed in Honduras. The patients' ages ranged from 3 months to 10 years, but 95% were younger than 3 years old. Since 1978, when 16 patients were reported, the yearly incidence has declined, and in 1982 only 4 patients were reported. We located and interviewed the families of 57 of the 69 patients. At the onset of illness, all 57 patients lived in rural areas, and 55 lived in southern Honduras. All the patients who were discharged from the hospital alive were still living at the time of the interview. A case-control study, using age-matched neighbors as controls, showed that patients were significantly more likely to have lived in poorly constructed, wood-stick houses. We used an indirect immunofluorescence test to analyze blood samples for Leishmania antibodies from 218 family members of patients, 170 family members of controls, and 156 children living on the island of El Tigre, where 4 of the 5 most recently diagnosed patients lived. Although 15 specimens gave a positive reaction to L. donovani antigen, each gave a stronger reaction when tested against Trypanosoma cruzi antigen, suggesting that the reactions to L. donovani were false positives. A serosurvey of 279 dogs of cases and controls and from El Tigre showed that 24 had positive reactions to L. donovani antigen, but only 4 (1.4%) had higher titers to L. donovani than to T. cruzi.(ABSTRACT TRUNCATED AT 250 WORDS)

Isolation of Leishmania braziliensis from Lutzomyia ovallesi (Diptera:Psychodidae) in Guatemala.

Leishmania braziliensis is endemic in Guatemala and Belize in Central America. To help identify the vector(s) of this parasite in Guatemala, phlebotomine sand flies that were aspirated from the clothing of collectors at Tikal National Park in the Department of the Peten were examined for flagellates. Lutzomyia ovallesi was found infected with flagellates that were identified as L. braziliensis by isoenzyme electrophoresis. The isoenzyme profile of this isolate matched those from humans from the same area.

Cutaneous leishmaniasis in Guatemala: comparison of diagnostic methods.

A comparison was made of methods used to diagnose suspected cutaneous leishmaniasis in Guatemala. The most sensitive method was a combination of thin smears made from superficial scrapings of the ulcers and inoculation of culture medium with either aspirates or scrapings. The diagnosis was confirmed in 252 (70%) of 362 patients. Ability to cultivate Leishmania was correlated with the concentration of amastigotes seen on thin smears. Leishmania were cultured in 42 (27%) of 153 patients with no amastigotes found in 400 oil-immersion fields and in 174 (83%) of 209 patients with at least 1 amastigote. No difference in diagnostic outcome was found when we compared smears or cultures taken from the center or the border of the ulcer or from an incision made tangential from the ulcer. We found no difference when we compared smears obtained with scalpels, capillary tubes, or dental broaches. The use of scrub brushes soaked in iodine neither decreased the rate of culturing parasites nor decreased contamination rates.

Placebo-controlled clinical trial of meglumine antimonate (glucantime) vs. localized controlled heat in the treatment of cutaneous leishmaniasis in Guatemala.

Sixty-six Guatemalans with parasitologically proven cutaneous leishmaniasis were randomly and equally divided into 3 treatment groups: those receiving meglumine antimonate (Glucantime), 850 mg antimony/day im for 15 days; those receiving localized controlled heat from a radio-frequency generator, 50 degrees C for 30 sec, 3 treatments at 7 day intervals; and those receiving treatment with a placebo. Of 53 isolates identified, 40 were Leishmania braziliensis braziliensis and 13 were L. mexicana mexicana. Thirteen weeks after beginning treatment, the number of patients from each group with completely healed and parasitologically negative lesions were as follows: meglumine antimonate, 16 (73%); localized heat, 16 (73%); and placebo, 6 (27%). The cure rate for those with infections due to L. b. braziliensis in each group was as follows: meglumine antimonate, 11 out of 14 (79%); controlled heat, 9 out of 14 (64%); and placebo, 0 out of 11.

Predictors of failure in timely tuberculosis treatment completion, United States.

SETTING: The US tuberculosis (TB) surveillance system. OBJECTIVE: To examine failure in timely TB treatment completion to identify interventions toward achieving the national goal of ≥ 93% treatment completion in ≤ 12 months among patients eligible for 6-9 month regimens. DESIGN: We examined 1993-2006 trends in timely treatment completion; for 2006 cases, we used Poisson regression to assess predictors for failure in timely completion. RESULTS: Timely treatment completion improved from 64% in 1993 to 84% in 2006, with similar trends among foreign- and US-born persons and racial/ethnic subgroups. Annual increases in timely completion were ≤ 1 percentage point during 1998-2006. Subpopulations at highest risk for failure in timely completion were persons with combined pulmonary and extra-pulmonary disease (foreign-born adjusted RR [aRR] 3.25, 95%CI 2.47-4.28; US-born aRR 2.75, 95%CI 1.98-3.83) or incarceration (foreign-born aRR 2.30, 95%CI 1.80-2.93; US-born aRR 1.71, 95%CI 1.36-2.14). Homelessness and human immunodeficiency virus infection were other risk factors. CONCLUSIONS: Particular attention to timely completion is needed for subpopulations requiring strong medical expertise in TB management and those at risk for treatment non-adherence, especially if foreign-born. Understanding and addressing causes of delayed completion and improving documentation of treatment completion among all cases will be crucial to achieving the US goal.

Cryptosporidiosis in humans: review of recent epidemiologic studies.

Since 1976, when Cryptosporidium was first recognized as a human pathogen, understanding of the epidemiology of this protozoan parasite has increased substantially. This review discusses 14 recently published studies of the occurrence of cryptosporidiosis in developed and developing countries and compares their findings with those of previous epidemiologic reports. These studies show that cryptosporidiosis is an important public health problem worldwide. Although cryptosporidiosis was first recognized as a problem in immunosuppressed patients, persons with normal immunologic function are also affected. This appears to be especially true for children in developing countries; of 1035 children with diarrhea reported in several surveys, 79 (7.6%) had Cryptosporidium. Findings from studies that included both asymptomatic as well as symptomatic persons have demonstrated that Cryptosporidium infections are rare in persons without symptoms, suggesting that Cryptosporidium should not be thought of as an opportunistic parasite. Early studies documented the potential for animal-to-human transmission of Cryptosporidium, but it is now clear that many, perhaps most, Cryptosporidium infections in humans are not acquired directly from infected animals. Although alternate modes of transmission are just beginning to be explored, evidence indicates that person-to-person spread is important.

Evaluation of the Arizona Medical Student Exchange Program.

In this article the authors describe and present an evaluation of the Arizona Medical Student Exchange Program of the Western Interstate Commission for Higher Education. The program is designed to help defray the cost that an Arizona student faces in attending an out-of-state medical school by paying, in the student's behalf, the difference between the resident and nonresident tuition at the out-of-state school. Furthermore, the accepting medical school is paid an additional sum as an inducement to accepts more Arizona students in the future. The program's goal is to increase the number of graduating physicians who will return to practice in Arizona, especially in areas of medical need. While the program apparently has been successful in increasing the number of Arizona students studying medicine and the number of physicians returning to the state--both to metropolitan areas and to areas of medical need--these increases have not kept pace with Arizona's growing population.

Cryptosporidiosis: clinical, epidemiologic, and parasitologic review.

Cryptosporidium, an intestinal protozoan parasite, is a well-known cause of diarrhea in animals but has been recognized only recently as a cause of human disease. Since 1976, 58 cases of cryptosporidiosis in humans have been reported; 18 of the patients had normal immune function, and 40 had various immunologic abnormalities, the most common of which, acquired immune deficiency syndrome (AIDS), occurred in 33 patients. Patients with normal immune function had self-limited diarrhea, but patients with immunologic abnormalities often developed severe, irreversible diarrhea; 22 patients have died. The diagnosis of cryptosporidiosis can now be made noninvasively, but increased diagnostic proficiency has led to little improvement in control or treatment of the disease. Although 23 compounds have been evaluated in experimentally infected animals and 20 drugs have been used in human clinical trials, no effective chemotherapeutic agent for cryptosporidiosis has been identified to date.

High-performance liquid chromatographic method for quantitation of pentamidine in blood serum.

A high-performance liquid chromatographic procedure has been developed for the determination of pentamidine concentrations in serum samples. A microbore, reversed-phase column was used with a mobile phase consisting of methanol and water with sodium heptanesulfonate and triethylamine as modifiers. Pentamidine could be extracted from serum only by the addition of an ion-pairing agent, di(2-ethylhexyl) phosphoric acid, to the chloroform used for extraction. The method can be used to reliably detect levels as low as 5 ng/ml. The pentamidine concentration in the serum of eleven patients 24 h after their tenth daily dose of pentamidine averaged 60 +/- 34 ng/ml.

The natural history of cutaneous leishmaniasis in Guatemala.

The natural history of American cutaneous leishmaniasis was studied in Guatemala by analyzing the characteristics of 355 untreated leishmanial lesions, observing the evolution of 57 lesions on persons who received a placebo in treatment trials, and analyzing data from a population-based survey concerning the duration of 82 untreated lesions. Of 25 lesions caused by Leishmania mexicana that were followed prospectively, 22 (88%) completely reepithelialized by a median lesion age of 14 weeks, and 17 (68%) were classified as cured (no residual wound inflammation or reactivation during at least 6 months of follow-up). In contrast, 7 (22%) of 32 lesions caused by Leishmania braziliensis reepithelialized by a median lesion age of 13 weeks, and only 2 (6%) cured. These data demonstrate that the species of Leishmania is the primary determinant of the clinical course and outcome of untreated lesions and underscore the need for field-applicable diagnostic techniques that provide rapid species identification.