Showing papers on "Outbreak published in 1990"

Enterically-transmitted non-A, non-B hepatitis.

Abstract: More than 50% of acute viral hepatitis occurring in some developing countries appears to be unrelated to infection by HAV or HBV and accumulating evidence suggests that a high proportion of this non-A, non-B hepatitis (NANB) is enterically transmitted. Epidemics or outbreaks of enterically-transmitted NANB (ET-NANB) have been documented in the Soviet Union, Nepal, Burma, Pakistan, India, Borneo, Somalia, Sudan, Ivory Coast, Algeria, and Mexico. These outbreaks primarily affect young to middle-age adults and are often associated with a high mortality rate in infected pregnant women, approaching 20% in most reported epidemics. Several investigators have reported finding 27 to 34 nm virus-like particles (VLPs) in stools of acutely infected cases. Stools containing these small, non-enveloped VLPs have been shown to cause NANB in experimentally infected cynomolgus macaques, African green monkeys, chimpanzees, rhesus monkeys, and Saguinus mystax monkeys (tamarins). Infected primates have been shown to seroconvert to 27-34 nm VLPs recovered from stools of cases occurring in the Soviet Union, India, Nepal, Burma, Pakistan and/or Mexico, suggesting that ET-NANB is caused by one virus or class of serologically related viruses. The morphological features and physicochemical properties of one candidate virus are very similar to those of some human caliciviruses, a group of viruses that is normally associated with outbreaks of severe diarrhoea.

Epidemic Transmission of Enterically Transmitted Non-A, Non-B Hepatitis in Mexico, 1986-1987

Abstract: Outbreaks of acute hepatitis occurred in Huitzililla and Telixtac, two rural villages 70 miles south of Mexico City, Mexico, in late 1986. The first outbreak began in Huitzililla in June of that year, 1 month after the start of the rainy season. A census revealed 94 icteric case subjects, for an attack rate of 5%; two women died. Attack rates were higher for persons older than 15 years (10%) than for younger persons. A case-control study showed that illness was highly associated with water-related factors. The second outbreak began in August 1986 in Telixtac. There were 129 case subjects, for an attack rate of 6%; one woman died. Epidemiologic findings were similar to those in Huitzililla, except that most disease transmission was not linked to unsafe water sources. None of 62 case subjects in Huitzililla and only 2 of 53 case subjects in Telixtac tested had serological evidence for recent infection with hepatitis A or B. Two of eight stool samples from Huitzililla and one of eight stool samples from Telixtac were positive by immune electron microscopy for 32- to 34-nm viruslike particles similar to those seen in cases of enterically transmitted non-A, non-B hepatitis from Asia. To our knowledge, these investigations document for the first time the epidemic transmission of enterically transmitted non-A, non-B hepatitis virus in the Americas. (JAMA. 1990;263:3281-3285)

Streptococcal Serogroup: A Epidemic in Norway 1987–1988

Abstract: A nationwide outbreak of Lancefield group A streptococcal (GAS) infections in Norway during the season 1987-88 is described. Data were collected from the Norwegian infectious disease notification system and supplemented by active search for cases of bacteraemia and other serious infections in addition to serotyping of selected clinical bacterial isolates. The number of reported cases of non-invasive GAS infections from week 29/1987 to week 28/1988 was 60% higher than expected. Between 1 Jan. and 30 June 1988, 84 cases of bacteraemia were notified, several with fulminant septicaemia and shock. The case fatality rate was 25%. Six cases of neonatal GAS septicaemia were seen. There was a nearly 3-fold total increase in occurrence of GAS bacteraemia compared with previous years, and the increase was marked particularly in cases among older children and adults 30-50 years old. Additional culture-confirmed diagnoses included unusual cases compared to recent decades such as pneumonia with empyema, necrotising fasciitis and primary peritonitis. Serotyping of strains collected consecutively from localized infections revealed a marked predominance of T-type 1, opacity factor negative strains (T-1 OF-), ranging from 41% in North Norway to 87% in Mid-Norway. M-typing confirmed that these strains were M-1, as were 87% of the preserved bacteraemia strains from the period described. Although most of the M-1 strains were distinctly mucoid only one case of acute rheumatic fever was reported during the first half of 1988. We conclude that an epidemic of GAS infections caused by M-1 strains has occurred in Norway resulting in an increase in both incidence and seriousness of disease.

Non-o group 1 vibrio cholerae : a look at the epidemiology of an occasional pathogen

Abstract: Non-O1 V. cholerae is a ubiquitous environmental isolate. It is a common contaminant of shellfish, and in the developing world, it is frequently isolated from food and water. Asymptomatic carriage rates approaching 4 percent have been described among persons involved in high-risk activities, such as eating oysters in New Orleans or going on pilgrimage to Mecca. The actual occurrence of disease appears to be much less common. This is an "occupational" pathogen which may be responsible for outbreaks or a high frequency of isolation in certain areas at specific times but which generally ranks as a minor cause of diarrheal disease. While host susceptibility and infectious dose may help explain the relatively infrequent occurrence of non-O1 V. cholerae-associated disease, it also appears likely that only a small minority of strains carry the necessary virulence factors to cause gastroenteritis. Unfortunately, there does not appear to be a single mechanism by which these organisms cause diarrhea; it is likely that we will find a heterogeneous pattern of virulence mechanisms, similar to the heterogeneity seen among diarrheagenic E. coli. As our understanding of these pathogenic mechanisms improves, there should be a corresponding refinement in our understanding of the epidemiology of these widely distributed organisms.

Outbreak of Salmonella typhimurium infection traced to contaminated chocolate and caused by a strain lacking the 60-megadalton virulence plasmid.

Abstract: We describe an outbreak of Salmonella typhimurium infection, caused by contaminated chocolate produced by one Norwegian company, which occurred in Norway and Finland in 1987. A total of 349 bacteriologically verified cases were recorded in Norway, and 12 cases were recorded in Finland. There was a predominance of young children among the patients (median age, 6 years), many of whom developed acute hemorrhagic diarrhea. The outbreak strain exhibited a rare phage lysis pattern and a characteristic plasmid profile lacking the 60-MDa virulence-associated plasmid. DNA hybridization failed to demonstrate any DNA sequence homology between the outbreak strain and the virulence plasmid. The outbreak strain was nonlethal for orally infected mice. The finding of only less than or equal to 10 S. typhimurium cells per 100 g of chocolate in about 90% of the positive samples obtained from retail outlets suggested that an inoculum of fewer than 10 organisms may have been sufficient to cause symptomatic disease.

An outbreak of Salmonella saint-paul infection associated with beansprouts.

Abstract: In March 1988, there was an outbreak of infection by a strain of Salmonella saint-paul with a distinctive antigenic marker. A total of 143 reports were received between 1 March and 7 June. Preliminary investigations suggested that raw beansprouts were a possible source of infection and a case-control study confirmed the association. S. saint-paul of the epidemic type was isolated from samples of beansprouts on retail sale in different cities in the United Kingdom and from mung bean seeds on the premises of the producer who was most strongly associated with cases. In addition, Salmonella virchow PT34 was isolated from samples of raw beansprouts and was subsequently associated with seven cases of infection. Four other serotypes of salmonella were also isolated from beansprouts. On 8 April the public were advised to boil beansprouts for 15 seconds before consumption, and the premises of the one producer associated with many cases were closed. As a result of these actions there was a significant decrease in the number of infections with S. saint-paul.

Viral agents of gastroenteritis. Public health importance and outbreak management.

Abstract: Each year, infectious gastroenteritis causes greater than 210,000 children in the United States to be hospitalized and 4-10 million children to die worldwide. Since the mid-1970s, knowledge has increased dramatically concerning the viral agents that are responsible for much of this public health burden. Rotavirus, the most common cause of diarrhea among children, infects virtually every child in the United States by the age of 4 years and causes potentially lethal dehydration in 0.75% of children less than 2 years of age. Other recently identified pathogens include the enteric adenoviruses, calicivirus, astrovirus, and the Norwalk family of agents. Conclusive diagnosis of these viruses requires electron microscopic examination of stool specimens, a laboratory technique that is available only at a few large centers, including CDC. Stool samples from an outbreak that are submitted to CDC for detection of viral pathology should be collected in bulk from 10 ill persons during their first 48 hours of illness, while feces are still liquid, and should be stored at 4 C (not frozen). Acute- and convalescent-phase serum samples should be collected from the same persons, plus from an equal number of controls, during the first week of illness and 3 weeks thereafter. Control measures for outbreaks of viral gastroenteritis should focus on the removal of an ongoing common source of infection (e.g., an ill food handler or the contamination of a water supply) and on the interruption of person-to-person transmission that can perpetuate an outbreak in a population after the common source has been removed. Because improvements in environmental hygiene may not be accompanied by reductions of endemic diarrhea caused by viruses, immunization may play an important role in future control; vaccine trials for rotavirus are in progress. In anticipation of vaccine development and use, CDC recently began national surveillance for the viral agents of gastroenteritis. Health-care facilities involved in the detection of rotavirus or the other viral agents of diarrhea can participate.

A statewide outbreak of escherichia coli 0157: h7 infections in washington state

Abstract: In November 1986, a statewide outbreak of Escherichia coli O157:H7 infections in Washington State was identified after a physician in an eastern Washington community hospitalized three patients with hemorrhagic colitis which progressed to thrombotic thrombocytopenic purpura. Epidemiologic investigation identified 37 cases in this community and linked the illnesses to a local restaurant which had served ground beef that was the suspected initial vehicle of transmission. The plasmid profile and toxin production pattern (Shiga-like toxin II alone) of the outbreak strain provided a unique strain marker. E. coli O157:H7 infections caused by this strain were simultaneously seen in other parts of the state among nursing home residents and in patients with the hemolytic-uremic syndrome, and an increase in sporadic cases of hemorrhagic colitis was noted at a Seattle health maintenance organization. It is suspected that a contaminated product, probably ground beef distributed statewide, was the common source. Tracing of this meat led to farms where rectal swabs from six (1%) of 539 cattle tested yielded E. coli O157:H7, although the plasmids and toxin production patterns of these isolates differed from the human outbreak strain. Introduction of a single strain of E. coli O157:H7 has the potential to cause widespread concurrent outbreaks. Such outbreaks are likely to escape recognition until heightened screening and surveillance for E. coli O157:H7 is established.

Pestivirus infections in ruminants other than cattle.

Abstract: Summary: Pestiviruses infect a wide range of domestic, captive and free-living ruminants. Among domestic livestock, Border disease virus is a well recognised cause of an important congenital disease of sheep in virtually all sheep-rearing countries of the world. The clinical signs, pathogenesis, diagnosis, epidemiology and control of this disease are described in detail. One natural outbreak of Border disease in domestic goats has been described and there is serological and virological evidence that pestiviruses occur widely in this species. A pestivirus has been isolated from a farmed red deer (Cervus elaphus) and there is serological evidence of a widespread low prevalence of infection among this new domestic species. Pestiviruses have been associated also with outbreaks of disease among captive ruminants in zoological collections. Among free-living ruminants, pestiviruses have been recovered from dead roe deer (Capreolus capreolus), fallow deer (Dama dama), African buffalo (Syncerus caffer), giraffe (Giraffa camelopardalis) and wildebeest (Connochaetes spp.) but in all these instances the contribution of the virus to the cause of the disease was uncertain. Serological surveys have shown that many species of freeliving ruminants in North America, Europe and Africa have varying prevalence rates of antibodies to pestiviruses.

An outbreak of human Semliki Forest virus infections in Central African Republic.

Abstract: Semliki Forest (SF) virus was responsible for an outbreak of febrile illnesses in Bangui, Central African Republic (CAR), during October-December 1987. The virus was isolated at first from mosquitoes, mainly Aedes africanus, collected August-October in a gallery forest 100 km from Bangui. During October-December, 22 isolations of SF virus were made from serum samples collected from patients in Bangui presenting with fever, severe persistent headache, myalgia, arthralgia, and a convalescence marked by asthenia. During the same period, 8 SF virus isolates were obtained from mosquitoes collected in Bangui, mainly from Ae. aegypti. Europeans, particularly soldiers who had recently arrived from France, were affected. Antibodies to alphaviruses had been previously detected in a high proportion of resident human populations in CAR. We conclude that SF virus is a human pathogen.

The isolation of lumpy skin disease virus and bovine herpesvirus-4 from cattle in Egypt.

Abstract: Lumpy skin disease (LSD) virus (LSDV) was isolated for the first time from cattle in Egypt in 2 disease outbreaks. Bovine herpesvirus-4 (BHV-4) and LSDV were detected in a pooled sample from the first outbreak (Suez). Only LSDV was isolated from the second outbreak (Ismalia). The capripoxviruses were identified as LSDV by neutralization with specific antiserum and by their ability to produce generalized LSD in experimentally inoculated cattle.

A nosocomial outbreak of Salmonella enteritidis infection due to the consumption of raw eggs.

Abstract: THE number of reported infections due to Salmonella serotype enteritidis increased six-fold in the northeastern United States from 1976 to 1986.1 , 2 Of the reported outbreaks of food-borne salmonellosis, infections due to S. enteritidis were more likely than those due to other salmonella serotypes to be associated with the consumption of foods containing eggs.3 In 1987, the New York City Department of Health and the New York State Department of Health investigated the largest nosocomial outbreak of S. enteritidis to have occurred in the United States, in which 404 of the 965 patients (42 percent) at one hospital were affected, and . . .

Group C rotavirus associated with fatal enteritis in a family outbreak.

Abstract: A family outbreak of gastroenteritis involving three adults and three children is described in which diarrhoea and vomiting were the main clinical features. One infant died in whom no pathogens could be detected in either small or large intestinal postmortem samples. Stool samples from two symptomatic siblings contained rotaviruses as demonstrated by electron microscopy. Both of these faecal samples were negative when assayed in a group A specific rotavirus enzyme-linked immunosorbent assay (ELISA) and subsequent genomic analysis of these rotaviruses was suggestive of group C rotavirus. Serological evidence showed that these atypical rotaviruses were members of serogroup C. Other atypical rotaviruses in faecal samples from sporadic cases in symptomatic children were detected over a similar time period and location. These had electrophoretic RNA profiles similar to those in the family outbreak. Furthermore, seroepidemiological studies detected group C rotavirus antibody in blood donors resident in the location of the family outbreak.

Varicella Outbreaks in Army Recruits From Puerto Rico Varicella Susceptibility in a Population From the Tropics

Abstract: • Two outbreaks of varicella consisting of a total of 105 cases occurred in a highly varicella-susceptible population of young adult Army recruits from Puerto Rico enrolled in the Defense Language Institute in San Antonio, Tex, between October 1986 and November 1987. Epidemiologic investigation found a significantly higher risk for enlisted recruits housed in open barracks than for officers housed in private rooms. The attack rate in the first outbreak was 30%, with an estimated attack rate of 71% among susceptible persons. Serologic testing of 810 adult recruits from Puerto Rico for varicella-zoster antibody by means of an enzyme-linked immunosorbent assay procedure found 42% to be seronegative, with no significant difference by sex. The enzyme-linked immunosorbent assay test had a positive predictive value for absence of disease development of 95% in the second outbreak. Serologic test results were successfully used as part of the outbreak control strategy, with a resultant decrease in attack rates to 19% overall and 30% among susceptible persons in the second outbreak. Uniquely susceptible adult populations placed in conditions with high likelihood of infection on exposure are potential candidates for the varicella vaccine after its licensure. ( Arch Intern Med. 1990;150:970-973)

Recovery of hepatitis A virus from a water supply responsible for a common source outbreak of hepatitis A.

Abstract: An outbreak of hepatitis A occurred in a north Georgia trailer park served by a private well. Of 18 residents who were serosusceptible to hepatitis A virus (HAV), 16 (89%) developed hepatitis A. Well water samples were collected 3 months after illness onset in the index case and 28 days after illness onset in the last trailer park resident. Hepatitis A virus antigen (HAVAg) was detected in the samples by enzyme immunoassay from three of the five cell lines following two 30-day passages and from a fourth cell line following a third passage of 21 days.

Food-borne outbreak of Giardia lamblia.

Abstract: An outbreak of giardiasis occurred following a family party for 25 persons. Nine who had eaten fruit salad became ill, compared with one who had not eaten the salad (Relative Risk = 7.4, 95% CI = 1.4, 169.3). The fruit salad preparer had a diapered child and a pet rabbit at home who were both positive for Giardia lamblia. This outbreak emphasizes the importance of good hygienic practices in food preparation and the possibility of domestic-animal-to-person transmission in Giardia outbreaks.

An outbreak of acute gastroenteritis caused by a small round structured virus in a geriatric convalescent facility.

Abstract: An outbreak of acute gastroenteritis (AGE) occurred in a 201-bed geriatric convalescent facility in Los Angeles County during December 1988 through January 1989. The attack rate was 55% among residents and 25% among employees. Illnesses were characterized by vomiting and diarrhea to a lesser extent, and the absence of fever. Bacterial and parasitic tests in a sample of patients were negative. A 27 nm small round structured virus (SRSV) was identified in one of 30 stools studied by immune electron microscopy (IEM). While rotavirus and influenza A and B were found in three, one and three cases, respectively, no alternative etiologic agent could be demonstrated for most cases. The outbreak met Centers for Disease Control (CDC) clinical and epidemiologic criteria for Norwalk-like gastroenteritis. The death rate of residents was not elevated beyond baseline during the outbreak; however, one healthy employee had diarrhea and dehydration and died after developing an arrhythmia. An autopsy showed moderate, diffuse lymphocytic and neutrophilic myocarditis, and viral studies found influenza A in left ventricular tissue. Fourteen (25%) of 57 employee cases worked in occupations without routine stool or patient contact. At least nine of these employees lacked evidence of direct fecal contact, and transmission of infection in these cases may have been airborne.

A Large Outbreak of Antibiotic-Resistant Shigellosis at a Mass Gathering

Abstract: In July 1987, a large outbreak of shigellosis occurred among attendees at a mass gathering in a national forest, the annual Rainbow Family Gathering. Sanitation in the campsite was poor, allowing widespread transmission of disease, probably by food, water, and person-to-person spread. The attack rate may have been greater than 50% among the estimated 12,700 attendees. The outbreak was caused by Shigella sonnei, resistant to ampicillin, tetracycline, and trimethoprim-sulfamethoxazole; the organism was of colicin type 9 and contained a 90-kilobase plasmid not found in non-outbreak-related strains. The dispersal of the group resulted in nationwide dissemination of the organism, and outbreaks in three states were linked to transmission from attendees at the Gathering. This outbreak demonstrates the potential for rapid dissemination of disease in such a setting and the necessity for careful planning of mass gatherings.

A waterborne outbreak of leptospirosis among United States military personnel in Okinawa, Japan.

Abstract: A waterborne outbreak of leptospirosis occurred among US military personnel during September 1987, on the island of Okinawa, Japan. Micro-agglutination titres for leptospiral antigen of greater than or equal to 200 were detected in hospitalized adult males averaging 22.5 years of age with symptoms compatible with leptospirosis. Epidemiological findings revealed two case clusters distinguished by time and place of exposure. The overall attack rates among recreational swimmers and combat skills training participants were 467/1000 (7/15) and 183/1000 (15/82), respectively. Swallowing of water differentiated individuals with laboratory-confirmed infection from those with no infection, while water immersion alone did not appear to result in leptospiral infection. Additionally, subnormal rainfall may have contributed to the risk of exposure associated with this outbreak.

Comparison of epidemic and endemic group G streptococci by restriction enzyme analysis.

Abstract: Restriction enzyme profiles of group G beta-hemolytic streptococci associated with a point source outbreak and an outbreak of sporadic pharyngitis in two different communities were compared. To asses the epidemiologic utility of this approach for studying group G streptococci, DNA fingerprints of strains responsible for a point source outbreak of pharyngitis associated with the consumption of contaminated food were compared with DNA fingerprints of pharyngeal isolates from children with pharyngitis seen at a pediatric practice during a 6-month period. In each epidemiologic situation, a single strain characterized by a unique restriction enzyme pattern predominated. The results are compatible with the conclusion that human infections could be limited to a few strains of group G streptococci which have the capacity to spread through a given population. The restriction enzyme profiles proved to be a highly specific and precise means of evaluating strain relatedness and of providing further understanding of the epidemiology of group G streptococcal infections.

Serotype-specific outbreak of group B meningococcal disease in Iquique, Chile

Abstract: From 1979 to August 1987, there have been 178 cases of meningococcal disease in Iquique, Chile, a city of about 140000. The attack rate for the last 5 years has been in excess of 20/100000 per year, more than 20 times greater than for the country overall. The mortality rate was 6%. The disease occurred in patients with ages from 4 months to 60 years, but 89% of cases were in patients < 21 years. The largest number of cases were in the age group 5—9 years (n = 54), but the highest incidence occurred in children less than 1 year of age (72·8/100000 per year). The male/female ratio was 1·2. Cases occurred all year round with little seasonal variation. Of the 178 cases, 173 were biologically confirmed. Serogroup analysis of strains from 135 patients revealed A = 1, B = 124, C = 10. Forty-four group B strains from 1985-7 were serotyped: 15:P1.3 = 36, 15:NT = 4, 4:P1.3 = 2, NT:NT = 2. Ten of 11 of the outbreak strains tested were sulfadiazine-resistant. This is the first recognized outbreak caused by a Gp B:15 strain in South America. It shares many of the characteristics of outbreaks caused by closely related strains in Europe, such as a predilection for older children and adolescents, sulfadiazine-resistance, and sustained high attack rates. The Iquique strain (B:15:P1.3) belongs to the same genetic clone (ET-5 complex) as the Norway (B:15:P1.16) and the Cuban (B:4:P1.15) strains.

Limited sequence heterogeneity among biologically distinct human immunodeficiency virus type 1 isolates from individuals involved in a clustered infectious outbreak

Abstract: Human immunodeficiency virus type 1 isolates were obtained over a 3-year period from blood, brain, and lung of three patients in a clustered infectious outbreak. This included a blood donor who was initially asymptomatic but subsequently developed AIDS-related complex and two neonatal transfusion recipients who developed AIDS. Isolates from brain and lung replicated to greater than 30-fold higher levels in primary monocyte cultures than did those from blood; no growth differences on primary lymphocytes were observed. Thirteen clones were obtained from seven isolates, and env sequences were determined. The predicted amino acid sequences among these clones differed by only 0.01% but differed by 15-27% when compared to previously sequenced isolates from other patients. The level of envelope amino acid sequence divergence noted among these isolates is considerably lower than that previously reported for other human immunodeficiency virus isolates. No differences in the envelope unique to lung or brain isolates compared to blood isolates were noted. This study provides evidence that mutations in the envelope may not be necessary for disease progression and that other portions of the viral genome may contribute to cell-specific tropism.

Recommendations for collection of laboratory specimens associated with outbreaks of gastroenteritis.

Abstract: Recent discoveries have implicated a number of "new" (i.e., previously unrecognized) infectious agents as important causes of outbreaks of gastroenteritis. Unfortunately, the ability to detect these agents in an outbreak can be limited by two factors: 1) the lack of appropriate assays-many of which are still in developmental stages and are not readily available to clinical laboratories, and 2) inadequately or improperly collected specimens. At CDC, many newly developed assays are being used for research and for outbreak investigations. The information in this report is especially intended for public health agencies that collaborate with CDC in investigating outbreaks of gastroenteritis. The report provides an update on guidelines and recommendations for the proper collection of specimens to be sent to CDC, gives general background information concerning some recently discovered pathogens, lists some of the tests available at CDC, and provides a list of CDC contacts. The guidelines and the general information provided on causes of outbreaks of gastroenteritis can be also used by public health workers for investigations when specific testing is available and appropriate.

The epidemic of foot-and-mouth disease in Saskatchewan, Canada, 1951-1952.

Abstract: The epidemic of foot-and-mouth disease in Saskatchewan in 1951 and 1952 was studied in order to determine origins of outbreaks and methods of spread. The epidemic was initially considered to be vesicular stomatitis and foot-and-mouth disease was not recognized until February 1952, three months after the initial infection. The reports prepared at that time were reviewed in order to obtain details of the numbers of animals infected and the source and date of infection for the outbreaks. Methods of spread were rated according to their likelihood. The introduction of infection by an immigrant through his clothes as well as by sausage was possible. The sequence of events from the first outbreak to the spread from a feedlot/packing plant and from a dairy farm, which failed to report the disease, were clarified. Methods of spread included movement of animals, animal products and people and the airborne route. Milk delivery and artificial insemination did not result in spread of infection. The quarantine of affected farms reduced spread by animals and deterred visits by people. The original diagnosis of vesicular stomatitis was due to misinterpretation of a lesion in an inoculated horse. Laboratory tests established the presence of foot-and-mouth disease. The limited extent of the epidemic, despite the delay in diagnosis, is attributed to (i) the low density of cattle, (ii) few infected pigs and hence less airborne virus and (iii) absence of waste food feeding and milk collection in addition to the limited quarantine imposed.