Laurene Mascola

• MD,MPH
• County of Los Angeles Public Health

Objectives: 1) Describe the characteristics of LAC travelers who were possibly exposed to EVD. 2) Evaluate the functionality of the LACDPH surveillance system to rapidly assess EVD risk and monitor travelers.

This study reviewed the demographics of persons using web reporting and the impact this method has on the quality of the initial information received from the public.

Objective: Determine the demographics and disease characteristics of cysticercosis cases as well as the trend in cases over time in Los Angeles County.

Study Objective: We conducted a survey of Los Angeles County residents with malaria who traveled abroad to assess prophylaxis use, knowledge of the disease, and differences in awareness by region visited.

Study Objective: We describe a population-based case series of 11 WNV-infected children reported in LAC in 2004.

Objectives External validity, or generalisability, is the measure of how well results from a study pertain to individuals in the target population. We assessed generalisability, with respect to socioeconomic status, of estimates from a matched case–control study of 13-valent pneumococcal conjugate vaccine effectiveness for the prevention of invasiv...

Background: Changes in herpes zoster (HZ) epidemiology are expected with childhood varicella vaccination. We reported previously that during 2000 to 2006 HZ incidence decreased 55% in children <10 years of age, while among 10- to 19-year olds it increased by 63%. We update the analysis with 4 additional years of data. Methods: Population-based a...

Objectives: We examined overall and incremental effectiveness of 2-dose varicella vaccination in preventing community transmission of varicella among children aged 4 to 18 years in 2 active surveillance sites. One-dose varicella vaccine effectiveness (VE) was examined in those aged 1 to 18 years. Methods: From May 2009 through June 2011, varicel...

Objective The Los Angeles County (LAC) Emergency Department (ED) Syndromic Surveillance System (SSS) classifies patients into syndrome categories based on stated chief complaints. In an effort to evaluate the accuracy of patient-stated chief complaints and final diagnoses, both " fever " chief complaints and diagnoses were compared with patient bod...

BACKGROUND: Coccidioidomycosis (Valley Fever), endemic to southern California, is an infection resulting from the inhalation of airborne spores of Coccidioides immitis or Coccidioides posadasii. Coccidioidomycosis has been a reportable disease in California since 1928, and is reportable within seven calendar days. We evaluated the Los Angeles Count...

BACKGROUND: In November 2013, Los Angeles County (LAC) Department of Public Health (DPH) was notified of five patients in a neonatal intensive care unit (NICU) with cultures positive for extended-spectrum β-lactamase (ESBL) producing Escherichia coli between October 1, 2013 and November 26, 2013. This is the first occurrence of an ESBL E. coli outb...

BACKGROUND: In October 2013, the Los Angeles County Department of Public Health (LAC-DPH) received a report of several persons ill with diarrhea, vomiting, abdominal cramps, fever, and nausea after attending a fundraising dinner for a private club. METHODS: A partial list of attendees was obtained during the facility inspection conducted by LAC-D...

BACKGROUND: Developed in 2001 by Los Angeles County Department of Medical Examiner-Coroner (DME-C) and Los Angeles County Department of Public Health (LAC-DPH), the Unusual Death Surveillance System (UDSS) functions to identify potential acts of bioterrorism and emerging infectious disease events in LAC. DME-C provides a 42-variable dataset for cor...

This report details an outbreak investigation conducted by the Los Angeles County Department of Public Health of 3 cases of bacterial infection among patients receiving hemodialysis who were treated at the same dialysis center in 2011. Improper disinfection of reusable dialyzers was hypothesized as the source of transmission.

Objective: One-dose varicella vaccination for children was introduced in the United States in 1995. In 2006, a second dose was recommended to further decrease varicella disease and outbreaks. We describe the impact of the 2-dose vaccination program on varicella incidence, severity, and outbreaks in 2 varicella active surveillance areas. Methods:...

BACKGROUND: Fungal endophthalmitis is a rare but serious infection that can cause vision loss. In March 2012, the California and Los Angeles County Departments of Public Health were notified of nine fungal endophthalmitis cases after retinal surgery at a California ambulatory surgical center. We investigated to identify the source and prevent addit...

BACKGROUND: Healthcare services are increasingly delivered in ambulatory care settings (ACSs). Literature quantifying reported healthcare-associated infection (HAI) outbreaks in ACSs is scarce. The objective of this analysis was to identify and characterize investigations for suspected and confirmed HAI outbreaks in ACSs in Los Angeles County (LAC)...

BACKGROUND: In 2006, as varicella outbreaks continued to occur in schools with high 1-dose varicella vaccination (VV) coverage, the Advisory Committee on Immunization Practices recommended implementation of a routine 2-dose VV program for children. In 2001, CA adopted single dose school entry requirements for kindergartners and children transferrin...

BACKGROUND: The objective of this analysis is to compare the quality of web complaints to those previously only received via telephone. We aim to characterize web based and telephone based complaints by determining the demographics of complainants, the characteristics of the complaints, and evaluate how this new reporting mechanism is impacting the...

BACKGROUND: On February 11, 2011, public health officials received an inquiry about an outbreak of legionellosis reported through social media by attendees of a conference held February 1–3. Several attendees indicated a legionellosis diagnosis. We investigated to characterize illnesses, identify etiology, and determine associated exposures. METH...

BACKGROUND: CRKP is an emerging multidrug resistant pathogen and the most frequently isolated species of carbapenem-resistant Enterobacteriaceae in the United States. CRKP has caused large nosocomial outbreaks and become endemic in certain hospitals on the East Coast, subsequently spreading across the United States. CRKP were thought to be rare and...

BACKGROUND: Mycobacterium fortuitum is a ubiquitous environmental bacterium increasingly associated with surgical-site infections (SSIs), causing disfiguring infections that require prolonged antibiotic regimens. In October 2011, an outbreak of five M. fortuitumSSIs was reported among patients at a Los Angeles County ambulatory plastic surgery cent...

Objective: Carbapenem-resistant Klebsiella pneumoniae (CRKP) is an emerging multidrug-resistant pathogen associated with higher mortality, longer hospital stays, and increased costs. CRKP was thought to be sporadic in Los Angeles County (LAC); however, the actual incidence is unknown. To address this, LAC declared CRKP a laboratory-reportable dise...

Among healthcare-associated infections (HAIs), Clostridium difficile is the most common cause of infectious diarrhea with an estimated 2.8 cases/10,000 patient days. In 2008, California mandated hospital reporting of HAIs including C. difficile infections (CDI) through the National Healthcare Safety Network (NHSN). To determine relationships betwee...

Background: Neisseria meningitidis(NM) is an important cause of meningitis and septicemia. Most IMD is caused by serogroups (SG) A, B, C, Y and W- 135, only B is not preventable by US vaccines. Vaccines have been recommended for high risk groups since 1981 and meningococcal conjugate vaccine (MCV4) has been endorsed for adolescents since 2005. LAC...

Background: Fungal endophthalmitis (FE) is a rare but serious infection that can cause vision loss. In March 2012, the California Department of Public Health and Los Angeles County Department of Public Health were notified of 9 cases of FE after retinal surgery at a California surgical center. An investigation was conducted to describe the outbreak...

Author Summary Neurocysticercosis (NCC) is considered one of the major neglected infections of poverty in the United States, with mortality studies indicating that California bears the highest burden of this disease. Although NCC is a reportable disease in California, studies indicate that this disease goes largely under-reported, contributing to t...

Strobe checklist. (PDF)

To describe varicella disease in infants since implementation of the varicella vaccination program in the United States. From 1995 to 2008, demographic, clinical, and epidemiologic data on cases of varicella in infants were collected prospectively through a community-based active surveillance project. We examined disease patterns for infants in 2 a...

Background: On February 11, 2011, public health officials received a journalist’s inquiry about an outbreak of respiratory illness reported through social media by attendees of a conference held during February 1–3. Several attendees indicated a legionellosis diagnosis. We investigated to characterize illnesses, identify etiology, and determine ass...

Background: In light of the pertussis epidemic in CA, evaluating adherence to the Advisory Committee on Immunization Practices (ACIP) recommended vaccine schedule is important. The ACIP recommends that children 4-6 years of age receive a second dose of varicella vaccine (2-VV) and a fifth dose of DTaP, (5-DTaP) unless the 4th dose was given on/afte...

Pending California legislation prompted an on-line survey of methicillin-resistant Staphylococcus aureus (MRSA) active surveillance practices administered to infection preventionists of all 102 acute care licensed hospitals in Los Angeles County. We describe reported surveillance methods. Ninety-six hospitals responded with 41% performing MRSA acti...

The objective of this study was to 1) assess the incidence of strongyloidiasis in the United States, 2) evaluate demographic and regional associations, and 3) identify comorbid conditions as risk factors for death. A population-based case-control study was performed by using mortality data during 1991-2006. We identified 347 strongyloidiasis deaths...

Statewide hospital discharge data were used to assess the economic burden of neurocysticercosis in Los Angeles County (LAC) from 1991 through 2008. A neurocysticercosis hospitalization was defined as having a discharge diagnosis of cysticercosis in addition to convulsions, seizures, hydrocephalus, cerebral edema or cerebral cysts. This study identi...

Background: The Varicella Active Surveillance Project has conducted population-based active surveillance for varicella disease in the AV since 1995. From 1995 to 2005 varicella incidence rates (VIR) declined by 90% and single dose vaccine coverage was 90% for LAC children <24 months. In 2006, the Advisory Committee on Immunization Practices endorse...

A point-of-dispensing clinic was held to distribute ciprofloxacin prophylaxis when 2 high school students were reported to the health department with invasive meningococcal disease. Of more than 3,100 school staff and students in attendance, 2,861 received prophylaxis. A survey was administered to students 2 weeks postclinic to better understand th...

Hepatitis A, an acute infectious disease caused by a virus, can be transmitted through the fecal-oral route by contaminated food and/or poor personal hygiene among food handlers and close contacts. In 2005-2006, a hepatitis A outbreak occurred, disproportionately affecting homeless residents and staff of homeless service organizations in downtown L...

Hospital discharge reports have provided data for studies of methicillin-resistant Staphylococcus aureus (MRSA) skin and soft-tissue infection (SSTI) studies. This analysis determined the sensitivity and positive predictive value of International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) code combinations to calcu...

We describe a pseudo-outbreak of respiratory syncytial virus infection in a neonatal intensive care unit at the White MemorialMedical Center in Los Angeles, California. Investigation of a reported cluster of cases in the early fall of 2007 identified false-positive results due to cross-reactivity between surfactant and a rapid immunoassay. This hig...

The varicella-zoster virus (VZV) vaccine strain may reactivate to cause herpes zoster. Limited data suggest that the risk of herpes zoster in vaccinated children could be lower than in children with naturally acquired varicella. We examine incidence trends, risk and epidemiologic and clinical features of herpes zoster disease among children and ado...

Trypanosoma cruzi infection (i.e., Chagas disease) is an unusual complication that can occur after solid-organ transplantation and that can result in severe illness or death. In 2006, there were 2 heart transplant recipients in Los Angeles, California, reported to have acute trypanosomiasis during the same month. We conducted an investigation to de...

Listeriosis is a relatively rare foodborne disease with significant public health implications. The causative pathogen, Listeria monocytogenes, grows well in refrigeration, is associated with a case-fatality rate of 20%, and causes an estimated 28% of all foodborne disease-related deaths. Nevertheless, data on the risk factors for listeriosis morta...

Although smallpox has been eradicated, health care providers in emergency departments (EDs) need to remain vigilant to its recognition. Smallpox can be confused with chickenpox. We describe suspected smallpox cases reported in Los Angeles County from 2002 to 2006 and highlight areas for education. We retrospectively reviewed suspected smallpox repo...

Listeria monocytogenes is among the most virulent foodborne pathogens, with 20% of clinical infections resulting in death. To explore listeriosis-associated mortality in the United States and to evaluate prevention efforts, we reviewed vital records over a 16-year period to assess demographic, temporal, and seasonal trends. Nonperinatal listeriosis...

BACKGROUND: Typhoid fever is an acute systemic infectious disease caused by Salmonella typhi which has no non-human reservoir. Recovered cases may become typhoid carriers who may pass the infection to others. Typhoid fever is a reportable disease in California. The Los Angeles County Department of Public Health (LACDPH) follows up on all reported c...

A distribution clinic was held to dispense ciprofloxacin (cipro) prophylaxis when two Los Angeles County high school (HS) students were reported to the health department (HD) with invasive meningococcal disease (MD). Despite revealing cases' names to permit assessment of direct case contact, 2861 persons of over 3100 in attendance requested and rec...

BACKGROUND: Cysticercosis is a parasitic infection caused by the larval form of the tapeworm Taenia solium found worldwide. Thirty-two percent of cysticercosis mortality reported nationally (1990-2002, N=221) occurs in Los Angeles County (LAC). METHODS: A review of recently reported LAC cases, as well as trends in reported cases, total hospitaliz...

Background: The lifetime risk of HZ is about 30%. Post-herpetic neuralgia (PHN), defined as persisting pain lasting > 90 days after HZ rash onset, is a common complication. In 2006, active surveillance for HZ was conducted for adults > 50 years, the same year HZ vaccine was recommended for persons > 60 years. Methods: 89 sites reported cases bi-wee...

In 2002, we investigated a cluster of patients with Alcaligenes xylosoxidans bloodstream infections by conducting a matched case-control study and a prospective study. Pulsed-field gel electrophoresis (PFGE) was performed on blood culture isolates, and 1 explanted central venous catheter (CVC) was tested for biofilm. We identified 12 cases of A. xy...

We describe trends and characteristics of varicella outbreaks identified in an active surveillance site from 1995 to 2005. Cases of varicella were reported to the active surveillance project, and outbreaks were defined retrospectively as ⩾5 varicella cases epidemiologically linked to a common setting that occurred within 1 incubation period. Outbre...

Background: Pseudomonas aeruginosa (PA) is a leading cause of hospital-acquired pneumonia among high risk patients. Improperly cleaned multiuse patient devices have been implicated in prior outbreaks of PA. On December 4, 2006, we were notified of 8 ventilator-dependent infants with PA-positive cultures in a neonatal intensive-care unit (NICU). Met...

Reported mortality rates from Clostridium difficile disease in the United States increased from 5.7 per million population in 1999 to 23.7 per million in 2004. Increased rates may be due to emergence of a highly virulent strain of C. difficile. Rates were higher for whites than for other racial/ethnic groups.

To determine risk factors for neonatal methicillin-resistant Staphylococcus aureus (MRSA) skin and soft-tissue infection in a well-infant nursery. Case-control studies. A well-infant nursery in a nonteaching, community hospital. Case infants were newborns in the nursery who were born in the period November 2003 through June 2004 and had onset of MR...

The introduction of universal varicella vaccination in 1995 has substantially reduced varicella-related morbidity and mortality in the United States. However, it remains unclear whether vaccine-induced immunity wanes over time, a condition that may result in increased susceptibility later in life, when the risk of serious complications may be great...

The purpose of this study was to assess the validity of self-reported history for varicella disease relative to serological evidence of varicella immunity in pregnant women attending antenatal care at clinics located in two diverse geographical locations in the U.S. (Antelope Valley, California, and Philadelphia) with high varicella vaccination cov...

Background: Only one previous report exists of transplant-transmitted Trypanosoma cruzi (TC) infection in the United States. No TC screening test is licensed for blood, solid organ, or tissue donors. In February 2006, two heart transplant recipients in Los Angeles were reported with acute trypanosomiasis. Methods: Organ procurement and transplantat...

Neisseria meningitidis is a leading cause of bacterial meningitis and septicemia in the United States. Approximately 10-15% of meningococcal patients died despite antimicrobial therapies. We used vital records to assess meningococcal disease mortality in the United States during 1990-2002. Meningococcal cases were defined as reported deaths with re...

Efforts to reduce bacterial contamination in platelets (PLTs) have led to implementation of tests for bacterial detection before product release. Although relatively rare as a human pathogen, Listeria monocytogenes often causes serious illness and has a case-fatality rate of 20 percent. PLTs from an asymptomatic 58- year-old Hispanic male with a lo...

In 2004, Los Angeles County confirmed 11 cases of symptomatic West Nile virus (WNV) infections in children younger than 18 years of age. Eight had WNV fever, 2 had meningitis and 1 had encephalitis. Fever, rash, nausea and vomiting were the most prominent symptoms at presentation; median duration of illness was 7 days. Clinicians should be aware of...

Methicillin-resistant Staphylococcus aureus (MRSA) has become increasingly common in neonatal intensive care units and can lead to severe outcomes. Baby C, of a set of quadruplets, died of MRSA sepsis. The surviving siblings were colonized with MRSA. Expressed breast milk was fed to all infants; tested breast milk samples were all MRSA-positive. Pu...

Background: In October, 2004, the Los Angeles County Department of Health Services (LACDHS) investigated a large outbreak of enterotoxigenic Escherichia coli (ETEC) infections following an international religious event. From 1975-2003, only 26 outbreaks of ETEC have been reported in the US. Methods: A case was defined as a person who ate food at th...

Background: In 2004, 137 cases of neuroinvasive disease (NID) and 149 West Nile Fever (WNF) cases were laboratory confirmed in LAC. Of these, only 11 (4%) were in children less than 18 years. Information regarding pediatric clinical presentation of WNV is limited. We describe a population-based case series of 11 WNV-infected children. Methods: Case...

Background: In 2004, 830 West Nile (WN) virus cases were reported in California (CA), 309 in Los Angeles County (LAC). Of those 148 were WN fever cases (WNF). WNF follow-up studies indicate a more severe illness than previously thought. We conducted a follow-up study of LAC-confirmed WNF cases comparing symptom duration and status in younger versus...

An outbreak of community-associated methicillin-resistant Staphylococcus aureus (MRSA) skin and soft tissue infection (SSTI) occurred in a college football team from August to September 2003. Eleven case-players were identified, and boils were the most common sign. Linemen had the highest attack rate (18%). Among 99 (93% of team) players with cultu...

Nationally, over 8 million people travel abroad every year to malaria endemic regions such as Asia (5 million), Latin America (3 million) and Africa (500K)1. In 2004, there were 1324 cases of malaria reported in the U.S., with 51 cases (4%) reported to the Los Angeles County (LAC) Health Department. All LAC reported malaria infections were acquired...

Invasive pneumococcal disease (IPD) is an important cause of morbidity and mortality in young children. In 2000, a 7-valent pneumococcal conjugate vaccine (PCV7) was licensed and recommended for IPD prevention in children.1 Subsequent decreases in IPD incidence in young children have been noted.2,3 However, population-based data are lacking on the...

Background: LAC has conducted population-based active surveillance for varicella in the Antelope Valley (AV), CA since 1995. From 1995 to 2003, varicella cases in AV have declined by 86%. We studied the trends in varicella outbreaks from 1995-2003. Methods: We performed varicella active surveillance at all reporting sites from 1995-2003. All report...

Limited data are available on the contagiousness of vaccinated varicella cases. To describe secondary attack rates within households according to disease history and vaccination status of the primary case and household contacts and to estimate varicella vaccine effectiveness. Population-based, active varicella surveillance project in a community of...

To describe the presentation and management of the first identified case of ocular vaccinia infection associated with the current smallpox vaccination program. Case report. Vaccinia virus was isolated by cell culture of a conjunctival swab. Direct staining with fluorescein isothiocyanate-labeled vaccinia antibody and polymerase chain reaction testi...

To identify characteristics of pregnant women who refuse HIV testing and determine predictive factors and the reasons for refusal, we conducted face-to-face interviews of pregnant women at prenatal clinics of public and private hospitals. We found 8% (n=65) of 826 pregnant women interviewed refused HIV testing. In bivariate analysis, foreign-born p...

The smallpox virus is a high-priority, Category-A agent that poses a global, terrorism security risk because it: (1) easily can be disseminated and transmitted from person to person; (2) results in high mortality rates and has the potential for a major public health impact; (3) might cause public panic and social disruption; and (4) requires specia...

The smallpox virus is a high-priority, Category-A agent that poses a global, terrorism security risk because it: (1) easily can be disseminated and transmitted from person to person; (2) results in high mortality rates and has the potential for a major public health impact; (3) might cause public panic and social disruption; and (4) requires specia...

Background: Since 1985 Listeria monocytogenes (LM) has been a reportable disease in LAC. To describe the epidemiology of listeriosis in LAC, we performed a cohort study using surveillance data from 1992 to 2002. Methods: A listeriosis case was defined by culturing LM from a normally sterile body site. A single perinatal case was defined as a mother...

Background: Salmonella is a frequent cause of foodborne illness in the United States. Trends in Salmonella incidence, hospitalization rates and outbreak etiologies in Los Angeles County from 1992-2001 are described. Methods: Routine case history data is collected on passively reported cases of salmonellosis. Hospital discharge data was obtained fro...

Background: Since 1995, varicella active surveillance has been conducted in three regions including Antelope Valley, CA where, by 2001, an 80% decline in disease had been observed. Post licensure studies in the United States have demonstrated 44-100% varicella vaccine effectiveness. However, limited data are available on vaccine effectiveness and t...

Background: Outbreaks of community-associated methicillin-resistant Staphylococcus aureus (CAMRSA) have been increasingly reported in correctional facilities, athletic teams, drug users, and schools. CAMRSA has been associated with invasive skin infections and appears to have a genotype distinct from nosocomial MRSA. The Panton-Valentine Leukocidin...

Background: Methicillin-resistant Staphylococcus aureus (MRSA) outbreaks have been increasingly reported in correctional facilities, IDUs, athletic teams, and ethnic minorities but little has been reported on hospitalization rates. The Los Angeles County Jail is the largest jail in the US (>20,000 inmates); the largest outbreak of MRSA in the US (N...

Adventure travel is becoming more popular, increasing the likelihood of contact with unusual pathogens. We investigated an outbreak of leptospirosis in "Eco-Challenge" multisport race athletes to determine illness etiology and implement public health measures. Of 304 athletes, we contacted 189 (62%) from the United States and 26 other countries. Ei...

Invasive aspergillosis (IA) is rare among renal transplant recipients (RTRs). We investigated a cluster of IA among RTRs at a California hospital from January to February 2001, when construction was ongoing. We conducted a cohort study among RTRs who were hospitalized between January 1 and February 5, 2001, to determine risk factors for IA. IA was...