Antimicrobial resistance in eight US hospitals along the US-Mexico border, 2000-2006.

Antimicrobial resistance (AR) is a growing problem worldwide and international travel, cross-border migration, and antimicrobial use may contribute to the introduction or emergence of AR. We examined AR rates and trends along the US-Mexico border by analysing microbiology data from eight US hospitals in three states bordering Mexico. Microbiology data were ascertained for the years 2000-2006 and for select healthcare and community pathogens including, three Gram-negative (Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae) and three Gram-positive (Staphylococcus aureus, Enterococcus, Streptococcus pneumoniae) pathogens and 10 antimicrobial-pathogen combinations. Resistance was highest in S. aureus (oxacillin resistance 45·7%), P. aeruginosa (quinolone resistance 22·3%), and E. coli (quinolone resistance 15·6%); six (60%) of the 10 antimicrobial-pathogen combinations studied had a significantly increasing trend in resistance over the study period. Potential contributing factors in the hospital and community such as infection control practices and antimicrobial use (prescription and non-prescription) should be explored further in the US-Mexico border region.

Prevention and control of rabies in an age of global travel: a review of travel- and trade-associated rabies events--United States, 1986-2012.

Rabies prevention and control efforts have been successful in reducing or eliminating virus circulation regionally through vaccination of specific reservoir populations. A notable example of this success is the elimination of canine rabies virus variant from the United States and many other countries. However, increased international travel and trade can pose risks for rapid, long-distance movements of ill or infected persons or animals. Such travel and trade can result in human exposures to rabies virus during travel or transit and could contribute to the re-introduction of canine rabies variant or transmission of other viral variants among animal host populations. We present a review of travel- and trade-associated rabies events that highlight international public health obligations and collaborative opportunities for rabies prevention and control in an age of global travel. Rabies is a fatal disease that warrants proactive coordination among international public health and travel industry partners (such as travel agents, tour companies and airlines) to protect human lives and to prevent the movement of viral variants among host populations.

Influenza-like illness surveillance on the California-Mexico border, 2004-2009.

BACKGROUND: Since 2004, the Naval Health Research Center, with San Diego and Imperial counties, has collaborated with the US Centers for Disease Control and Prevention to conduct respiratory disease surveillance in the US-Mexico border region. In 2007, the Secretariat of Health, Mexico and the Institute of Public Health of Baja California joined the collaboration. OBJECTIVES: The identification of circulating respiratory pathogens in respiratory specimens from patients with influenza-like illness (ILI). METHODS: Demographic, symptom information and respiratory swabs were collected from enrollees who met the case definition for ILI. Specimens underwent PCR testing and culture in virology and bacteriology. RESULTS: From 2004 through 2009, 1855 persons were sampled. Overall, 36% of the participants had a pathogen identified. The most frequent pathogen was influenza (25%), with those aged 6-15 years the most frequently affected. In April 2009, a young female participant from Imperial County, California, was among the first documented cases of 2009 H1N1. Additional pathogens included influenza B, adenovirus, parainfluenza virus, respiratory syncytial virus, enterovirus, herpes simplex virus, Streptococcus pneumoniae, and Streptococcus pyogenes. CONCLUSIONS: The US-Mexico border is one of the busiest in the world, with a large number of daily crossings. Due to its traffic, this area is an ideal location for surveillance sites. We identified a pathogen in 36% of the specimens tested, with influenza A the most common pathogen. A number of other viral and bacterial respiratory pathogens were identified. An understanding of the incidence of respiratory pathogens in border populations is useful for development of regional vaccination and disease prevention responses.

The impact of health communication and enhanced laboratory-based surveillance on detection of cyclosporiasis outbreaks in California.

We investigated the timing of diagnosis, influence of media information on testing for Cyclospora, and the method used to identify cases during eight cyclosporiasis outbreaks in California in spring of 1997. We found that Internet information, media reports, and enhanced laboratory surveillance improved detection of these outbreaks.

An outbreak of Salmonella serogroup Saphra due to cantaloupes from Mexico.

An outbreak of Salmonella serogroup Saphra (S. saphra) infections was studied by laboratory-based surveillance, case-control and trace-back studies, and a survey of cantaloupe preparation practices. Twenty-four patients with S. saphra infections had illness onsets between 23 February and 15 May 1997; 75% were

Provider-reported illness and absence due to illness among children attending child-care homes and centers in San Diego, Calif.

PURPOSE: To compare the incidence of provider-reported illness and absence due to illness among children attending small child-care homes, large child-care homes, and child care centers in a large metropolitan area. METHODS: From July 6, 1992, through January 28, 1994, we collected information from child-care providers on illness and absence due to illness at 64 small and 58 large child-care homes and 41 child-care centers. This included 113 446 child-weeks of information on 5360 children. RESULTS: Providers reported 14 474 illness episodes (6.6 episodes per child-year) and 8593 days of absence due to illness (3.9 days per child-year). The incidence of illness episodes was greatest in children who were younger than 1 year, white, or enrolled in small child-care homes. The incidence of absence due to illness was greatest in children who were 1 year of age, Hispanic, or enrolled in child-care centers. Respiratory symptoms were most commonly associated with illness episodes and absence due to illness. CONCLUSIONS: Children in child-care homes had a greater incidence of provider-reported illness than did those in centers. This risk varied by the type of facility and was greatest in small child-care homes. The increased risk for absence due to illness among children in child-care centers reflects exclusion and attendance patterns. It may be possible to reduce the incidence of absence due to illness and subsequent economic impact of child-care-associated illness by educating providers on exclusion guidelines.

A model immunization demonstration for preschoolers in an inner-city barrio, San Diego, California, 1992-1994.

An immunization demonstration project was conducted in an inner-city Latino neighborhood in San Diego to address underimmunization of children of preschool age. The project attempted interventions on consumer, provider, and system levels to reduce barriers to immunization and raise immunization rates. Free walk-in immunization clinics with emphasis on cultural sensitivity and that incorporated computerized reminder/recall were established. An educational series was offered to community health center (CHC) providers, and extensive community-based outreach and education took place in schools, churches, a WIC site, etc. Evaluation activities included preintervention and postintervention provider knowledge, attitudes, and practice surveys, CHC chart audits, and household surveys in the intervention ZIP code area and a control ZIP code area. Immunization coverage for 4DPT, 3OPV, and 1MMR (4:3:1) among two-year-olds increased significantly from 37% to 50% overall, and to 59% in the 1991 birth cohort in the intervention area compared to a one percentage point overall increase in the control area. Coverage improved significantly and missed opportunities decreased in one intervention CHC that participated most actively in educational inservices. While the Year 2000 U.S. Public Health Service objective of 90% 4:3:1 coverage for two-year-olds was not achieved over the 21-month course of the project, the results approached the 1996 single-antigen objectives. This demonstration underscores the importance of multilevel interventions including low cost, no appointment, and culturally appropriate immunization services for the indigent; the use of computerized reminder systems; and provider assessment, education, and feedback in the effort to raise preschool immunization levels. Medical Subject Headings (MeSH): immunization, preschool-age children, health promotion, provider education, immunization monitoring and follow-up systems, pediatric immunization standards, household surveys.

Chlamydia trachomatis infection among Hispanic women in the California-Mexico border area, 1993: establishing screening criteria in a primary care setting.

BACKGROUND: Chlamydia prevalence and transmission patterns in California-Mexico border communities are unknown, and selective screening strategies for Hispanic populations have not been evaluated. GOAL OF THIS STUDY: To determine chlamydia prevalence among Hispanic women in the California-Mexico border area and established screening criteria. STUDY DESIGN: This was a cross-sectional prevalence survey of family planning/prenatal Hispanic clients (n = 2378) in San Diego and Imperial Counties, California, and Tijuana, Mexico. RESULTS: Overall, chlamydia prevalence was 3.2% (3.3% in California; 2.1% in Mexico). Women born in Mexico or those who visited Mexico for at least 1 week in the recent past had a prevalence rate similar to women without those characteristics. Multivariate analysis showed that young age (less than 25 years old), unmarried status, or having clinical signs of a chlamydia syndrome (primarily cervicitis) or vaginosis independently predicted chlamydia infection. Applying minimum screening criteria recommended by the Centers for Disease Control would require screening less than half of the clients. However, only 69% of infections would be identified. Using survey-based criteria (less than 25 years old, unmarried, and clinical signs of a chlamydia syndrome) would require screening 64% of clients, but would identify 92% of those infected. CONCLUSION: Chlamydia prevalence among Hispanic women seeking reproductive healthcare was similar (< 5%) on both sides of the California-Mexico border. Among Hispanic women, using easily obtained demographic data (age and marital status) and clinical signs (primarily cervicitis), an effective selective screening strategy can be implemented.

PIP: During January 1-October 15, 1993, three clinics in Imperial County, California, located east of the coastal mountain range which borders Baja California; a large community health center in San Diego County, California; and a public health/family planning clinic in Tijuana in Baja California, Mexico, successfully screened 2378 Hispanic women for Chlamydia trachomatis. The overall chlamydia prevalence was 3.2% (2.1% in Tijuana; 3.3% in California). Chlamydia was more common among the prenatal clients than family planning clients (4.7% vs. 2.6%; p 0.02). Adolescents had the highest chlamydia infection rate (7.5%). Women born in Mexico or those who visited Mexico for at least one week during the last three months had a similar chlamydia prevalence rate as those born in the US or those who had not visited Mexico recently. The multivariate analysis revealed that significant independent predictors of chlamydia infection included young age (25 years) (prevalence ratio [PR] = 4.5 for 20 years and 2.5 for 20-24 years), unmarried status (PR = 2), high risk sex behavior (PR = 1.1), exposure to a sexually transmitted disease (PR = 2.6), discharge/bleeding (PR = 1.4), vaginosis (PR = 3.6), and cervicitis (i.e., chlamydia syndrome) (PR = 6). If the clinics had applied the minimum screening criteria recommended by the US Centers for Disease Control, less than 50% of the clients would have been screened. Yet it would have identified only 69% of chlamydia infections. If clinics would apply the criteria identified in this survey, they would need to screen 64% of their clients, which would identify 92% of clients infected with chlamydia. These findings indicate that, in the California-Mexico border region, chlamydia prevalence among Hispanic women seeking reproductive health care was comparable. They also show that clinics can implement an effective selective screening strategy.

Measles reporting completeness during a community-wide epidemic in inner-city Los Angeles.

A study was undertaken to determine the extent of measles underreporting among preschool-age children. In two community surveys conducted in inner-city Los Angeles during 1990 and 1991, respondents were asked whether preschool-age children in their households had ever been ill with measles. Information about measles episodes was obtained and medical records were reviewed, when available. A probable measles case was defined as having 3 or more days of rash with fever of 38.3 degrees centigrade or greater, and either cough, coryza, or conjunctivitis. To determine the proportion of cases reported, probable measles cases identified were matched with measles cases reported to the Los Angeles County Department of Health Services. Of the 947 children ages 6 weeks through 59 months included in the surveys, 35 children had experienced an illness episode which met the probable measles case definition. Ten (29 percent) of the 35 probable measles cases were reported to the health department. Hospitals reported 9 (69 percent) of 13 probable measles cases evaluated while private physicians' offices reported 0 (0 percent) of 12 evaluated (Fisher's exact test, P < 0.001), although 5 children were seen by private physicians before rash onset. Reporting was more complete for cases occurring during 1990 and 1991 (33 percent) than from 1987 through 1989 (18 percent). The hospitalization rate for preschool-age children with probable measles cases in the catchment area was estimated to be 8 percent (95 percent confidence interval = 0 to 18 percent). Although measles is a serious communicable disease which is almost completely preventable, cases of it among preschool-age children in this high incidence area were substantially underreported,especially by private physicians. Due to reporting bias, reported measles cases were representative of more severe cases than all the cases that occurred.

Syphilis in San Diego County 1983-1992: crack cocaine, prostitution, and the limitations of partner notification.

BACKGROUND AND OBJECTIVES: Recent epidemics of syphilis have been associated with crack cocaine use and anonymous sex for drugs, suggesting a potential limitation of sex partner notification as a disease control strategy. To assess these factors in an inner city epidemic of syphilis in San Diego County, California, we performed a descriptive epidemiologic analysis. STUDY DESIGN: Descriptive epidemiologic data were obtained from case investigation reports of primary and secondary syphilis. RESULTS: In the middle and late phases of the epidemic (1990-1992), the incidence of syphilis in the inner city area was more than six times that in remainder of the county. Illegal drug use was reported by 30% of patients. Drug use, especially crack cocaine, was related to prostitution. The estimated total number of sex partners per patient ratio was 4.2, whereas the named sex partners per patient ratio was only 1.5. Twenty-two percent of patients did not report any named partners. Overall, only 26% of the estimated total number of sex partners received treatment. CONCLUSIONS: Expanding partner notification to include more high-risk persons identified through social networks and increasing screening among high-risk populations may improve control of inner city drug/prostitution-related syphilis epidemics.

Measles epidemic from failure to immunize.

During 1988 through 1990, California experienced its worst measles epidemic in more than a decade, with 16,400 reported cases, 3,390 hospital admissions, and 75 deaths. More than half of the patients were younger than 5 years; the highest incidence was among infants younger than 12 months. The epidemic centered in low-income Hispanic communities in southern and central California. The major cause of the epidemic was low immunization levels among preschool-aged children and young adults. Rates of complications, admission to hospital, and death were surprisingly high. Outbreak control efforts met with indeterminate success. Problems with these efforts included insufficient funding early in the epidemic and disappointing public response to community-based immunization campaigns. The cost of medical care and outbreak control for the epidemic is conservatively estimated at $30.9 million. Unless the level of immunization in preschool-aged children is increased, this type of epidemic will probably recur.

A suburban focus of endemic typhus in Los Angeles County: association with seropositive domestic cats and opossums.

Thirty-three cases of locally acquired murine typhus were reported in Los Angeles County residents from May 1984 through February 1988. Only eight cases were reported over the previous 20-year period. Thirty (91%) cases resided within a suburban area encompassing approximately 50 km2 in northcentral Los Angeles or had contact with an animal from this area. Serologic testing (complement fixation and indirect fluorescent antibody) of selected animals in close association with human cases revealed a high prevalence of seropositivity among domestic cats and opossums. Nine (90%) of 10 resident cats tested had demonstrable antibody titers compared with none (0%) of 20 cats from a control area (P < 0.001). Suburban typhus cases were more likely than neighborhood controls to own a cat or dog (odds ratio = 6.9, 95% confidence interval = 1.8, 25.9, P = 0.002). Sixteen (42%) of 38 opossums trapped in close proximity to the residences of cases were seropositive versus none (0%) of 36 opossums from control areas (P < 0.001) A low frequency (2.8%) of seropositivity was found in commensal rodents, and the classic vector of murine typhus, Xenopsylla cheopis, was not found. Ectoparasite indices form seropositive opossums revealed heavy infestations with the cat flea, Ctenocephalides felis (mean flea count = 104.7), a species that readily bites humans. These data provide evidence that a suburban focus of murine typhus exists in Los Angeles that differs substantially from the classic transmission cycle, and that cats, opossums and C. felis may play an important role in the occurrence of human cases.

Cysticercosis surveillance: locally acquired and travel-related infections and detection of intestinal tapeworm carriers in Los Angeles County.

A surveillance system for cysticercosis was initiated in January 1988 in Los Angeles County to measure the incidence of the disease, to more accurately assess the level of locally acquired and travel-related infection, and to evaluate household contacts for intestinal tapeworm infection. In three years of surveillance (1988-1990), 138 incident cases were reported for an average crude annual incidence rate of 0.6 per 100,000 population. The highest rates were among Hispanics (1.6/100,000), most of whom were Mexican immigrants. Eight (5.8%) cases were fatal. Nine (6.5%) probable travel-associated cases occurred among persons born in the United States who had traveled to Mexico. Ten (7.2%) autochthonous cases of cysticercosis were documented. Taenia eggs were recovered more commonly in specimens from contacts with cysticercosis cases (1.1%) than in specimens from noncontact patients (0.2%). At least one Taenia tapeworm carrier was found among contacts of five (6.9%) of 72 cysticercosis patients. Carriers were more likely to be found among contacts of patients born in the United States (22.2%) than among those of foreign-born (4.8%) patients (odds ratio = 5.4) Cysticercosis causes appreciable morbidity and mortality in Los Angeles County, principally among Hispanic immigrants. However, these results indicate that both travel-acquired and locally acquired cysticercosis may be more common than previously recognized. Public health followup of cysticercosis cases, including screening of household contacts, can identify tapeworm carriers, who can be treated and removed as potential sources of further infection.

Risk factors for invasive Haemophilus influenzae type b in Los Angeles County children 18-60 months of age.

Potential factors that confer risk or protection for invasive Haemophilus influenzae type b disease were evaluated in Los Angeles County children 18-60 months of age by case-control methods. In this age group, 79 H. influenzae type b cases were identified by overlapping surveillance methods, and 221 random controls were selected by random digit dialing. Cases and controls were similar in sex, prior health, proportion attending day care, parental educational level, history of breast feeding, and proportion vaccinated with measles/mumps/rubella vaccine. The effect of H. influenzae type b vaccination was controlled in all analyses, and results of vaccine efficacy have been reported elsewhere. Cases were more likely to have a significant underlying medical condition, reside in home with more than six residents, have a lower yearly household income, have two or more smokers in the home, and to be black. Using conditional logistic regression models, the following were significant independent risk factors after adjusting for age, month of diagnosis, H. influenzae type b vaccine status, and the other factors: 1) more than two smokers in the house (odds ratio (OR) = 6.00; 95% confidence interval (CI) 1.49-24.06); 2) household size of more than six persons (OR for more than six vs. less than three persons = 3.71; 95% CI 1.10-12.60); and 3) black maternal race (OR for black vs. Hispanic = 3.47; 95% CI 1.41-8.53). We conclude that exposure to smoking in the home, living in households with more than six members, and the black race are each independently associated with an increased risk for H. influenzae type b disease in Los Angeles County children and, when combined, constitute a major reason for H. influenzae type b disease occurrence.

Characterization of Neisseria meningitidis serogroup C by multilocus enzyme electrophoresis and ribosomal DNA restriction profiles (ribotyping).

We compared multilocus enzyme electrophoresis (MEE) and ribosomal DNA fingerprinting (ribotyping) for subtyping 44 strains of Neisseria meningitidis serogroup C that were isolated in Los Angeles County, California, between December 1985 and July 1986. The isolates were divided into six enzyme types (ETs) by MEE, but 36 of the isolates were clustered in one ET, 3. The same isolates were divided into 17 ribotypes by use of restriction endonucleases ClaI, EcoRI, and XhoI. Twenty of the 36 ET 3 isolates were divided into 17 ribotypes by use of restriction endonucleases ClaI, EcoRI, and XhoI. Twenty of the 36 ET 3 isolates were grouped in a single ribotype, J. The rate of infection with ribotype J strains was higher in the southern part of the study area than in the northern part. Isolates from each of eight pairs (each isolate pair was cultured from the same patient from the same or different sites) were found identical by MEE, but ribotyping revealed a difference in one pair. In this study, ribotyping showed a greater discriminating capacity than MEE for subtyping N. meningitidis serogroup C, but the epidemiologic relevance of this increased sensitivity needs further assessment.

Prevalence of antibody to Trypanosoma cruzi among blood donors in Los Angeles, California.

Transfusion-associated Chagas' disease is a serious public health problem in Central and South America. With the recent influx of immigrants from Chagas' disease-endemic areas, concern about the risk of disease from blood transfusion has increased in the United States. To assess the prevalence of Trypanosoma cruzi infection in one area, 1024 consecutive blood donations from 988 voluntary blood donors at a medical center in Los Angeles County were screened serologically. The median age of donors screened was 32.5 years; 53.4 percent were male, and 38.4 percent were born in Chagas' disease-endemic countries. All donor sera were tested by complement fixation (CF) and indirect immunofluorescence (IIF) tests. A radioimmunoprecipitation assay (RIPA) was also done on all sera from CF- or IIF-reactive donors and an equal number of sera from nonreactive donors. A second serum specimen was obtained, and interviews were completed for 18 (67%) of 27 donors with an initial CF titer greater than or equal to 8 or an IIF titer greater than or equal to 64. The overall seroreactivity (by CF and IIF) was 1.1 percent (11/988). One donor (0.1%) had antibody specific to the 72- and 90-kDa antigens of T. cruzi on RIPA. Seven recipients of blood components from the seroreactive donors were located and were seronegative at 3 to 6 months. Seroreactive donors were 3.6 times more likely to have been born or to have resided in Mexico or Central America, 8.7 times more likely to have donated blood in the past, and 11.8 times more likely to have a history of malaria prophylaxis or treatment.

Meningococcal disease in the United States--1986. Meningococcal Disease Study Group.

Active surveillance for invasive meningococcal disease was conducted during 1986 and 1987 in six areas of the United States with a total population of approximately 34 million persons. The incidence of meningococcal disease was 1.3:10(5). The highest incidence of disease among the surveillance areas was in Los Angeles County (1.65:10(5). Neisseria meningitidis serogroups B and C caused about equal amounts of disease, which reflects a recent increase in the incidence of group C disease. Group C caused more than half of the cases of meningococcal disease in Los Angeles and Tennessee but less than one-third of the cases in Missouri and Oklahoma. Multilocus enzyme electrophoresis demonstrated that a group of closely related isolates of N. meningitidis was prevalent in Los Angeles during the surveillance period and was associated with an increased incidence of meningococcal disease there.