Risk-based cost modelling of oral rabies vaccine interventions for raccoon rabies

Distribution of oral rabies vaccine (ORV) is an effective but costly strategy to control raccoon rabies. Because of high costs, ORV for raccoon rabies in the U.S. has been limited primarily to epizootic areas, leaving extensive raccoon rabies regions without any ORV intervention. Several cost scenarios for ORV application in raccoon rabies enzootic and epizootic regions were modelled in New York State to obtain estimated costs of ORV baits per scenario and potential savings compared with a uniform ORV baiting strategy. These cost scenarios modelled at the census tract, level the application of ORV baits at different densities according to levels of risk defined by the observed number of raccoon rabies cases per km2 and the expected number of cases per km2 estimated with a Poisson regression model. Bait purchase costs were lower using the modelled cost scenarios than a uniform baiting strategy, for both the NYS enzootic region and the Long Island epizootic zone. The proportion of savings for the NYS enzootic region was 29.57%, and the proportion of savings for the Long Island epizootic zone was 38.9%. Use of these cost scenarios to determine bait distribution by rabies risk level should be considered to maximize efficacy and reduce costs of ORV interventions.

Evaluation of tickborne encephalitis case classification in Poland

Central European tickborne encephalitis (TBE) is a viral disease of the central nervous system. Despite a surveillance system for TBE existing in Poland since 1970, there are no standardised case definitions and different diagnostic tests are used in various regions. The purpose of this study was to summarise four years of surveillance data using standardised case definitions. From 1999 to 2002, 607 cases of TBE were reported to Poland’s national surveillance system: 386 (63.6%) were males, 331 (54.5%) lived in rural areas, and 186 (30.6%) were between 30 and 50 years old. Of 606 diagnosed cases, 453 (74.7%) had aseptic meningitis, 109 (18.0%) had meningoencephalitis, and 44 (7.3%) had meningoencephalomyelitis. Of the 607 reported cases, 602 (99.2%) could be classified: 153 (25.4%) as confirmed, 343 (57.0%) as probable, and 106 (17.6%) as possible cases. There was a significant difference in classified cases by gender: 28.6% of male cases were classified as confirmed, compared with 19.7% of female cases (chi2= 10.48, p=0.0053). There was a significant difference in case classification by clinical diagnosis: 32.4% of cases with meningoencephalitis were classified as confirmed cases, compared with 24.7% of cases with aseptic meningitis (chi2=11.79, p=0.019). There were also significant differences in the distribution by case definition group across geographical regions. For appropriate monitoring of TBE, a uniform and valid case definition should be used in European countries. With only 25% of reported cases meeting the definition for confirmed cases, there is a need for more complete follow-up and standardised testing of suspect cases.

Evaluation of tickborne encephalitis case classification in Poland

Central European tickborne encephalitis (TBE) is a viral disease of the central nervous system. Despite a surveillance system for TBE existing in Poland since 1970, there are no standardised case definitions and different diagnostic tests are used in various regions. The purpose of this study was to summarise four years of surveillance data using standardised case definitions. From 1999 to 2002, 607 cases of TBE were reported to Poland's national surveillance system: 386 (63.6%) were males, 331 (54.5%) lived in rural areas, and 186 (30.6%) were between 30 and 50 years old. Of 606 diagnosed cases, 453 (74.7%) had aseptic meningitis, 109 (18.0%) had meningoencephalitis, and 44 (7.3%) had meningoencephalomyelitis. Of the 607 reported cases, 602 (99.2%) could be classified: 153 (25.4%) as confirmed, 343 (57.0%) as probable, and 106 (17.6%) as possible cases. There was a significant difference in classified cases by gender: 28.6% of male cases were classified as confirmed, compared with 19.7% of female cases (chi2= 10.48, p=0.0053). There was a significant difference in case classification by clinical diagnosis: 32.4% of cases with meningoencephalitis were classified as confirmed cases, compared with 24.7% of cases with aseptic meningitis (chi2=11.79, p=0.019). There were also significant differences in the distribution by case definition group across geographical regions. For appropriate monitoring of TBE, a uniform and valid case definition should be used in European countries. With only 25% of reported cases meeting the definition for confirmed cases, there is a need for more complete follow-up and standardised testing of suspect cases.

"Neon needles" in a haystack: the advantages of passive surveillance for West Nile virus

Passive surveillance is usually viewed as less efficient for case ascertainment than active surveillance. However, for diseases with nonhuman animal reservoirs, active surveillance can be like looking for a needle in a haystack and may be prohibitively expensive. Fortunately for surveillance of West Nile virus (WNV) in the northeast US, the dead crows have served as "neon needles in a haystack"--indicators of viral activity that call attention to themselves. In 2000, laboratory testing of dead birds, including all species, birds found singly, with signs of trauma, or no compatible pathology, provided the first confirmation of viral activity in most areas. The surveillance factor most closely associated with the number of human cases was the dead crow density. In 2001, dead crow densities will be used as an additional index for monitoring human risk and need for prevention and control activities. If there are few crows in an area, if their case-fatality rate is reduced, or if there is public complacency about reporting dead crow sightings, this passive surveillance indicator may not be helpful in identifying areas likely to have occasional human cases or an outbreak.

West Nile virus: a case study in how NY State Health Information infrastructure facilitates preparation and response to disease outbreaks

New York's (NY) Health Information Network (HIN) provided timely access to West Nile Virus (WNV) data during the initial outbreak in the late Summer 1999. In December 1999, NY developed a plan to deal with WNV in 2000 that required an integrated surveillance system for humans, birds, mammals, and mosquitoes. The HIN infrastructure allowed NY to deploy this system statewide in three months. Local health departments throughout NY used the system to report, track, and retrieve surveillance data as WNV spread throughout NY in 2000. The HIN infrastructure includes partnerships, training/support, technical capacity and architecture similar to NEDSS as proposed by the US CDC.

Dead bird surveillance as an early warning system for West Nile virus

As part of West Nile (WN) virus surveillance in New York State in 2000, 71,332 ill or dead birds were reported; 17,571 (24.6%) of these were American Crows. Of 3,976 dead birds tested, 1,263 (31.8%) were positive for WN virus. Viral activity was first confirmed in 60 of the state's 62 counties with WN virus-positive dead birds. Pathologic findings compatible with WN virus were seen in 1,576 birds (39.6% of those tested), of which 832 (52.8%) were positive for WN virus. Dead crow reports preceded confirmation of viral activity by several months, and WN virus-positive birds were found >3 months before the onset of human cases. Dead bird surveillance appears to be valuable for early detection of WN virus and for guiding public education and mosquito control efforts.

West Nile virus infection in birds and mosquitoes, New York State, 2000

West Nile (WN) virus was found throughout New York State in 2000, with the epicenter in New York City and surrounding counties. We tested 3,403 dead birds and 9,954 mosquito pools for WN virus during the transmission season. Sixty-three avian species, representing 30 families and 14 orders, tested positive for WN virus. The highest proportion of dead birds that tested positive for WN virus was in American Crows in the epicenter (67% positive, n=907). Eight mosquito species, representing four genera, were positive for WN virus. The minimum infection rate per 1,000 mosquitoes (MIR) was highest for Culex pipiens in the epicenter: 3.53 for the entire season and 7.49 for the peak week of August 13. Staten Island had the highest MIR (11.42 for Cx. pipiens), which was associated with the highest proportion of dead American Crows that tested positive for WN virus (92%, n=48) and the highest number of human cases (n=10).

Crow deaths as a sentinel surveillance system for West Nile virus in the northeastern United States, 1999

In addition to human encephalitis and meningitis cases, the West Nile (WN) virus outbreak in the summer and fall of 1999 in New York State resulted in bird deaths in New York, New Jersey, and Connecticut. From August to December 1999, 295 dead birds were laboratory-confirmed with WN virus infection; 262 (89%) were American Crows (Corvus brachyrhynchos). The New York State Department of Health received reports of 17,339 dead birds, including 5,697 (33%) crows; in Connecticut 1,040 dead crows were reported. Bird deaths were critical in identifying WN virus as the cause of the human outbreak and defining its geographic and temporal limits. If established before a WN virus outbreak, a surveillance system based on bird deaths may provide a sensitive method of detecting WN virus.

Widespread West Nile virus activity, eastern United States, 2000

In 1999, the U.S. West Nile (WN) virus epidemic was preceded by widespread reports of avian deaths. In 2000, ArboNET, a cooperative WN virus surveillance system, was implemented to monitor the sentinel epizootic that precedes human infection. This report summarizes 2000 surveillance data, documents widespread virus activity in 2000, and demonstrates the utility of monitoring virus activity in animals to identify human risk for infection.

Mosquito surveillance and polymerase chain reaction detection of West Nile virus, New York State

West Nile (WN) virus was detected in the metropolitan New York City (NYC) area during the summer and fall of 1999. Sixty-two human cases, 7 fatal, were documented. The New York State Department of Health initiated a departmental effort to implement a statewide mosquito and virus surveillance system. During the 2000 arbovirus surveillance season, we collected 317,676 mosquitoes, submitted 9,952 pools for virus testing, and detected 363 WN virus-positive pools by polymerase chain reaction (PCR). Eight species of mosquitoes were found infected. Our mosquito surveillance system complemented other surveillance systems in the state to identify relative risk for human exposure to WN virus. PCR WN virus-positive mosquitoes were detected in NYC and six counties in the lower Hudson River Valley and metropolitan NYC area. Collective surveillance activities suggest that WN virus can disperse throughout the state and may impact local health jurisdictions in the state in future years.

Dead crow densities and human cases of West Nile virus, New York State, 2000

In 2000, Staten Island, New York, reported 10 human West Nile virus cases and high densities of dead crows. Surrounding counties with <2 human cases had moderate dead crow densities, and upstate counties with no human cases had low dead crow densities. Monitoring such densities may be helpful because this factor may be determined without the delays associated with specimen collection and testing.

Pertechnetate scintigraphy in primary congenital hypothyroidism

Primary congenital hypothyroidism (PCH) is currently detected effectively by heel-stick screening. When elevated thyrotropin (TSH) and/or decreased T4 are found in the blood of neonates, they are recalled, values are confirmed in venous blood and thyroxine replacement therapy (TRT) is immediately instituted, thus cretinism or severe retardation is prevented. However, in a significant percentage of neonates with abnormal blood levels of T4 or TSH, the disorder is transient. To help determine the exact cause of PCH and the possibility of transient PCH, pinhole thyroid imaging is performed 30 min after an intravenous injection of 18.5 MBq (500 microCi) 99mTc-pertechnetate (TcPT). Patients with a nonvisualized gland or patients with images suggesting dyshormonogenesis are reevaluated at age 3-4 y to exclude transient PCH.

METHODS

To define the role of TcPT imaging in determining the exact etiology of PCH and the possibility of its being transient, we reviewed data from 103 neonates with PCH who had scintigraphy in our laboratory between 1970 and 1996 and we correlated the results with clinical outcome.

RESULTS

Four patterns of thyroid scintigrams were recognized and these determined patient classification: (a) normal in 7 patients with false-positive heel-stick screening but normal venous blood hormone levels; (b) hypoplasia-ectopia in 32 patients requiring lifelong TRT; (c) nonvisualization in 35 patients-32 with agenesis requiring lifelong TRT and 3 with fetal thyroid suppression by maternal antibodies whose TRT was discontinued at a later age; and (d) dyshormonogenesis (markedly increased TcPT concentration) in 29 patients-25 with permanent PCH requiring lifelong TRT and 4 with transient PCH in whom TRT was discontinued. Of the 25 patients with dyshormonogenesis, 12 belonged to five families with two or three siblings having the same disorder.

CONCLUSION

TcPT thyroid scintigraphy in the neonate with PCH provides a more specific diagnosis, is useful for selecting patients for re-evaluation to uncover transient PCH and discontinue TRT and defines dyshormonogenesis, which is familial and requires genetic counseling. It is also cost-effective.

Risk for metabolic control problems in minority youth with diabetes

OBJECTIVE

We examined and quantified the degree of risk for poor glycemic control and hospitalizations for diabetic ketoacidosis (DKA) among black, Hispanic, and white children and adolescents with diabetes.

RESEARCH DESIGN AND METHODS

We examined ethnic differences in metabolic control among 68 black, 145 Hispanic, and 44 white children and adolescents with type 1 diabetes (mean age 12.9 [range 1-21] years), who were primarily of low socioeconomic status. Clinical and demographic data were obtained by medical chart review. Glycohemoglobins were standardized and compared across ethnic groups. Odds ratios among the ethnic groups for poor glycemic control and hospitalizations for DKA were also calculated.

RESULTS

The ethnic groups were not different with respect to age, BMI, insulin dose, or hospitalizations for DKA, but black children were older at the time of diagnosis than Hispanics (P < 0.05) and were less likely to have private health insurance than white and Hispanic children (P < 0.001). Black youths had higher glycohemoglobin levels than white and Hispanic youths (P < 0.001 after controlling for age at diagnosis). Black youths were also at greatest risk for poor glycemic control (OR = 3.9, relative to whites; OR = 2.5, relative to Hispanics).

CONCLUSIONS

These results underscore and quantify the increased risk for glycemic control problems of lower-income, black children with diabetes. In the absence of effective intervention, these youths are likely to be overrepresented in the health care system as a result of increased health complications related to diabetes.

Clinical, biochemical, and molecular investigations of a genetic isolate of growth hormone insensitivity (Laron's syndrome)

We have characterized the GH receptor mutation that is responsible for extreme short stature and GH insensitivity in a Bahamian genetic isolate. Heights of affected individuals ranged from -4.0 to -6.3 SD. Like others with Laron's syndrome, they had normal to high serum GH concentrations and low serum insulin-like growth factor I concentrations. Circulating levels of GH-binding protein activity were below limits of detection. Amplification of exons 2-7 and screening with single strand conformational polymorphism analysis located an abnormality in exon 7. Sequencing identified homozygosity for a C to T transition in the third position of codon 236. Reverse transcription and PCR amplification of complementary DNA from lymphocytes showed that this same sense mutation generated a new splice donor site 63 bp 5' to the normal exon 7 splice site. This novel site was used to the exclusion of the normal site in homozygotes. Both normal and variant messenger ribonucleic acid species were detected in heterozygotes. The predicted protein lacks 21 amino acids, including those defining the WS-like motif of the GH receptor extracellular domain. The high frequency of Laron's syndrome in this isolated island population probably reflects the introduction of the G236 splice mutation by a settler early in the 300-yr history of English settlement.

Yersinia pestis infection in three dogs

Yersinia pestis infection was diagnosed in 3 dogs. Clinical signs included lethargy (3 dogs), pyrexia (2 dogs), and a purulent skin lesion in the cervical region (2 dogs). Yersinia pestis infection is a potentially fatal zoonotic disease of human beings. Human cases have resulted from contact with infected domestic cats; however, the risk of human infection from contact with infected domestic dogs is unknown. Dogs frequently are exposed to Y pestis in areas in which there are plague epizootics; however, clinical illness in dogs is rare. In the western United States, where Yersinia pestis is endemic, plague should be considered in the differential diagnosis when examining dogs with nonspecific fever and lethargy.

Effect of intravenous insulin-like growth factor I in two patients with leprechaunism

Leprechaunism (Donohue syndrome) is an autosomal recessive disorder characterized by hyperglycemia, extreme insulin resistance, dysmorphic features, failure to thrive, and early death. In this study, recombinant IGF-I, which has both insulin-like and anabolic effects, was administered to two infants with leprechaunism in an attempt to reduce hyperglycemia and improve nutritional status. IGF-I was infused for 66 h in patient FL-1 and 62 h in patient NC-2, with maximal infusion rates of 110 and 40 micrograms/kg/h, respectively. Although supraphysiologic concentrations of IGF-I were achieved (459 and 1583 micrograms/L in FL-1 and NC-2, respectively), there were no apparent glucose-lowering or nitrogen-sparing effects. Insulin concentrations decreased from extremely high values (16804 and 10224 pmol/L) but remained elevated (611 pmol/L in FL-1 and 5869 pmol/L in NC-2). No changes in serum and urinary urea nitrogen or electrolytes occurred. IGF binding protein-2, which was the predominant IGF binding protein in serum by ligand blot and immunoblot, did not change with IGF-I infusion. IGF binding protein-3 levels were low at baseline and increased slightly during the infusion. We hypothesize that the lack of significant glucose-lowering and anabolic responses to IGF-I could be secondary to a postreceptor defect in IGF-I signaling resulting from the absence of functional insulin receptors.

Breast cancer among Hispanics, American Indians and non-Hispanic whites in New Mexico

Variation in breast cancer occurrence among women in New Mexico's three major ethnic groups has not previously been assessed. The address the descriptive epidemiology of breast cancer in New Mexico Hispanics, American Indians, and non-Hispanic whites, we calculated incidence rates from population-based registry data covering 1969-1987 and mortality data collected from 1958 to 1987. Breast cancer incidence and mortality rates for New Mexico's non-Hispanic white women were comparable to those for white women nationwide. In contrast, American Indian women had extremely low incidence and mortality rates for breast cancer; rates for Hispanics were intermediate, but well below those for non-Hispanic white women throughout the study period. Pronounced temporal trends in breast cancer occurrence were evident among Hispanic women, with the incidence rate increasing by 56% over the 19 years of available data and the mortality rate increasing by nearly 100% over 30 years. Age-specific incidence and mortality rates increased at all ages for successive birth cohorts of Hispanic women. For non-Hispanic whites, increasing incidence and mortality rates were also observed, but the increments were much smaller, approximately 15% for incidence and 30% for mortality. Our data show substantial ethnic differences in breast cancer incidence and mortality in New Mexico, suggesting the need for aetiological investigations to assist in controlling this disease.

Clinical, clinicopathologic, and pathologic features of plague in cats: 119 cases (1977-1988)

The clinical, clinicopathologic, and pathologic features of 119 cases of plague in cats from 1977 to 1988 in New Mexico were reviewed. Fifty-three percent were bubonic, 10% were pneumonic, 8% were septicemic, and 29% with neither buboes nor pneumonia were unclassified (but presumed septicemic). Three quarters of the lymphadenopathy was submandibular, and almost half of this was bilateral. One third of all cats had the triad of lethargy, anorexia, and fever in addition to buboes; one quarter had this triad plus abscesses. The overall mortality rate was 33%, with the greatest risk of death in pneumonic cases. For confirmatory diagnosis with a single laboratory test, fluorescent antibody was most frequently used (39% of cases). Cultures and passive hemagluttination titers were also used for confirmation. Gross and histologic findings depended on the type of plague, with Yersinia pestis organisms visualized in buboes of cats with bubonic plague and in the alveolar spaces and respiratory tubules of cats with pneumonic plague.

Eosinophilia-myalgia syndrome: findings on chest radiographs in 18 patients

Findings on chest radiographs of 18 patients with the eosinophilia-myalgia syndrome were compared and correlated with peak eosinophil counts. Nine patients had normal chest radiographs. Of the nine patients with abnormal chest radiographs, three had fine, irregular linear opacities in the lungs (the opacities were most noticeable at the bases); three had similar irregular linear opacities and pleural effusions; and three had pleural effusions and confluent opacities. One patient demonstrated an enlarged heart; no pulmonary edema was seen in this patient or in any others. Although the mean recorded eosinophil cell counts were higher in those patients with abnormal chest radiographs (6,340 vs 5,454/mm3 [6.3 vs 5.4 x 10(9)/L]), the difference was not statistically significant.

Eosinophilia-myalgia syndrome. A clinical case series of 21 patients. New Mexico Eosinophilia-Myalgia Syndrome Study Group

We reviewed 21 cases of eosinophilia-myalgia syndrome to describe the range of clinical findings in these patients. Most patients were women (20 [95%]) and middle-aged (mean, 46 years) and had taken the food supplement L-tryptophan (95%). All cases involved eosinophilia (eosinophil count, greater than or equal to 2.0 x 10(9)/L) and incapacitating myalgias. Fourteen (88%) of the 16 patients tested had mild liver function abnormalities. Aldolase levels were abnormal in all patients tested. Muscle biopsies were done in five patients; four showed eosinophilic perimyositis, and one had interstitial inflammation. No physical finding was pathognomonic or universal, but muscle tenderness, tachycardia, and rash were the most common signs found during physical examinations. Seven patients were treated with prednisone, and six showed improvement in muscle pain and a decrease in eosinophilia. The cause of this disorder is still unknown.

Risk factors for tornado injuries

Tornadoes in North and South Carolina on 28 March 1984 caused 252 people to be injured seriously enough to require hospitalization and 59 to be killed. To evaluate risk factors, we gathered information on 238 (94%) of those hospitalized and 46 (78%) of those killed. Those hospitalized or deceased had statistically significantly more deep cuts, concussions, unconsciousness and broken bones than those with them at the time of the tornado who were not hospitalized or killed. People living in mobile homes were more likely to be hospitalized or die than people occupying conventional houses. Other risk factors for hospitalization or death included advanced age (60+ years), no physical protection (not having been covered with a blanket or other object), having been struck by broken window glass or other falling objects, home lifted off its foundation, collapsed ceiling or floor, or walls blown away. More awareness of the tornado risk before it strikes and better adherence to tornado protection guidelines could reduce injuries and deaths in the future.

Height screening in the community. The commercialization of growth. The role of the pediatrician

The availability of unlimited but costly supplies of biosynthetic growth hormone has led to pressure for pharmacologic use (as opposed to replacement therapy in proven deficiency states). Commercial and altruistic motives have converged to promote community height screening among individuals who have been perceived by themselves or parents as short. This does not meet accepted criteria for health screening. Height screening of large populations of children yields few unrecognized medical conditions. If the goal of community screening is to identify abnormally short individuals (less than 3%) who might benefit from growth hormone treatment and if the unproven assumption is correct that stature correlates with success and happiness, then those less likely to appear for screening need to be recruited to avoid elitist domination. The annual cost of such growth promotion would be greater than $10 billion, with no evidence for substantial health benefits. Growth monitoring of all children through improved height measurement in schools and in physicians offices, as part of health supervision, is a more sound community approach than height screening.

L-tryptophan and eosinophilia-myalgia syndrome in New Mexico

On Oct 30, 1989, the New Mexico Health and Environment Department learned of 3 patients with eosinophilia and severe myalgia who had been taking L-tryptophan. Further review of these and similar cases led to the initial recognition of the eosinophilia-myalgia syndrome (EMS) epidemic. To elucidate the apparent association between L-tryptophan-containing products (LTCPs) and EMS a case-control study was done. The case definition was unexplained peripheral eosinophilia (2000/microliters or more) and incapacitating myalgia. Cases were found through review of white blood cell counts from May 1 to Oct 31, 1989, in nine medical laboratories in New Mexico. 11 cases and 22 matched controls were interviewed for information on symptoms and other clinical findings, on the use of LTCPs, and on potential confounding factors. All 11 cases (100%) used LTCPs compared with only 2 controls. These findings led to a ban on the sale of LTCPs in New Mexico, followed by a nationwide recall of such preparations in the United States.

Feline plague in New Mexico: risk factors and transmission to humans

The epidemiologic features of 60 cases of feline plague from 1977-1985 in New Mexico are reviewed. The most frequent clinical presentation was lethargy, anorexia, fever, and enlarged lymph nodes or abscesses. A history of hunting rodents was reported in 75 per cent of all cases. Five human plague cases were associated with five feline cases. Recommendations are presented for prevention of plague infection and transmission to humans, including restraining cats from roaming and hunting by neutering and keeping them indoors, treating them for fleas, and seeking medical care for febrile illnesses, especially when accompanied by enlarged lymph nodes.

A multistate outbreak of gastrointestinal illness caused by enterotoxigenic Escherichia coli in imported semisoft cheese

In September 1983, three clusters of gastrointestinal illness with similar symptoms affected 45 persons in Washington, D.C., after office parties. The illness lasted a mean of 4.4 days and was characterized by watery diarrhea (91%), abdominal cramps (80%), headache (38%), nausea (38%), and subjective fever (20%). Illness was strongly associated with having eaten imported French Brie cheese one to six days before onset of illness (P less than .0001 by Fisher's two-tailed exact test). After publicity about these outbreaks, additional cheese-associated cases were identified over an eight-week period in Illinois, Wisconsin, Georgia, and Colorado. Stool specimens from ill persons in four states yielded Escherichia coli serotype O27:H20. These organisms produced heat-stable enterotoxin and had similar plasmid profiles. When commercially distributed foods are contaminated, enterotoxigenic E. coli can cause widespread disease even in a developed country, and the disease can easily escape correct diagnosis.

R factor-mediated antibiotic resistance in Shigella

The infectivities of herpes simplex virus types 1 and 2 were inactivated by silver nitrate at concentrations of 30 μM or less, which did not affect at all the infectivities of hemagglutinating virus of Japan, vesicular stomatitis virus, poliovirus, vaccinia virus, and adenovirus. The inactivated virus retained the capability of adsorbing to the cell, with an adsorption kinetics quite similar to that of intact virus, and of inducing the concanavalin A agglutinability in the infected cells, whereas it lost completely the capability of producing viral antigens and other cytopathic changes.

Extensive urban outbreak caused by antibiotic-sensitive Shigella sonnei

During 1970 and 1971, a large increase in the number of isolations of Shigella organisms (90% S sonnei) occurred among patients of Grady Memorial Hospital in Atlanta. Examination of strains isolated during this outbreak showed a marked decline in the frequency of antibiotic resistance, especially multiple resistance, from that which had been observed during the preceding three years, in spite of continued heavy usage of antibiotics. These findings are contrary to most recently reported experience, which has indicated a rapidly increasing incidence of antibiotic resistance, especially to ampicillin.