Francisco Alvarado-Ramy

Update: Ongoing Zika Virus Transmission — Puerto Rico, November 1, 2015–July 7, 2016

Zika virus is a flavivirus transmitted primarily by Aedes aegypti and Aedes albopictus mosquitoes, and infection can be asymptomatic or result in an acute febrile illness with rash (1). Zika virus infection during pregnancy is a cause of microcephaly and other severe birth defects (2). Infection has also been associated with Guillain-Barré syndrome (GBS) (3) and severe thrombocytopenia (4,5). In December 2015, the Puerto Rico Department of Health (PRDH) reported the first locally acquired case of Zika virus infection. This report provides an update to the epidemiology of and public health response to ongoing Zika virus transmission in Puerto Rico (6,7). A confirmed case of Zika virus infection is defined as a positive result for Zika virus testing by reverse transcription-polymerase chain reaction (RT-PCR) for Zika virus in a blood or urine specimen. A presumptive case is defined as a positive result by Zika virus immunoglobulin M (IgM) enzyme-linked immunosorbent assay (MAC-ELISA)* and a negative result by dengue virus IgM ELISA, or a positive test result by Zika IgM MAC-ELISA in a pregnant woman. An unspecified flavivirus case is defined as positive or equivocal results for both Zika and dengue virus by IgM ELISA. During November 1, 2015-July 7, 2016, a total of 23,487 persons were evaluated by PRDH and CDC Dengue Branch for Zika virus infection, including asymptomatic pregnant women and persons with signs or symptoms consistent with Zika virus disease or suspected GBS; 5,582 (24%) confirmed and presumptive Zika virus cases were identified. Persons with Zika virus infection were residents of 77 (99%) of Puerto Ricos 78 municipalities. During 2016, the percentage of positive Zika virus infection cases among symptomatic males and nonpregnant females who were tested increased from 14% in February to 64% in June. Among 9,343 pregnant women tested, 672 had confirmed or presumptive Zika virus infection, including 441 (66%) symptomatic women and 231 (34%) asymptomatic women. One patient died after developing severe thrombocytopenia (4). Evidence of Zika virus infection or recent unspecified flavivirus infection was detected in 21 patients with confirmed GBS. The widespread outbreak and accelerating increase in the number of cases in Puerto Rico warrants intensified vector control and personal protective behaviors to prevent new infections, particularly among pregnant women.

Nasal Carriage of Methicillin-Resistant Staphylococcus aureus in an American Indian Population

BACKGROUND AND OBJECTIVE Although reports of methicillin-resistant Staphylococcus aureus (MRSA) infections without healthcare exposure are increasing, population-based data regarding nasal colonization are lacking. We assessed the prevalence of and risk factors for community-associated MRSA nasal carriage in patients of a rural outpatient clinic. DESIGN A cross-sectional population survey was conducted through random sample and stratification by community of residence. Recent healthcare exposure (ie, hospitalization, dialysis, or healthcare occupation) and other risk factors for MRSA carriage were assessed. Cultures of the nares were performed. Community-associated MRSA was defined as MRSA carriage without healthcare exposure. SETTING A predominantly American Indian community in Washington. PATIENTS Those receiving healthcare from an Indian Health Service clinic. RESULTS Of 1,311 individuals identified for study, 475 (36%) participated. Unsatisfactory culture specimens resulted in exclusion of 6 participants. In all, 128 (27.3%) of 469 participants had S. aureus. Nine (1.9%) of 469 had MRSA carriage; of these, 5 had community-associated MRSA (5 of 469; overall community-associated MRSA carriage rate, 1.1%). MRSA carriage was associated with antimicrobial use in the previous year (risk ratio [RR], 7.2; P = .04) and residence in a household of more than 7 individuals (RR, 4.5; P = .03). Pulsed-field gel electrophoresis indicated that 5 (55%) of 9 MRSA carriage isolates were closely related, including 3 (60%) of 5 that were community associated. CONCLUSIONS Prevalence of community-associated MRSA colonization was approximately 1% in this rural, American Indian population. Community-associated MRSA colonization was associated with recent antimicrobial use and larger household.

First confirmed cases of Middle East respiratory syndrome coronavirus (MERS-CoV) infection in the United States, updated information on the epidemiology of MERS-CoV infection, and guidance for the public, clinicians, and public health authorities - May 2014

Since mid-March 2014, the frequency with which cases of Middle East respiratory syndrome coronavirus (MERS-CoV) infection have been reported has increased, with the majority of recent cases reported from Saudi Arabia and United Arab Emirates (UAE). In addition, the frequency with which travel-associated MERS cases have been reported and the number of countries that have reported them to the World Health Organization (WHO) have also increased. The first case of MERS in the United States, identified in a traveler recently returned from Saudi Arabia, was reported to CDC by the Indiana State Department of Health on May 1, 2014, and confirmed by CDC on May 2. A second imported case of MERS in the United States, identified in a traveler from Saudi Arabia having no connection with the first case, was reported to CDC by the Florida Department of Health on May 11, 2014. The purpose of this report is to alert clinicians, health officials, and others to increase awareness of the need to consider MERS-CoV infection in persons who have recently traveled from countries in or near the Arabian Peninsula. This report summarizes recent epidemiologic information, provides preliminary descriptions of the cases reported from Indiana and Florida, and updates CDC guidance about patient evaluation, home care and isolation, specimen collection, and travel as of May 13, 2014.

Epidemic parenteral exposure to volatile sulfur-containing compounds at a hemodialysis center.

OBJECTIVE To determine the cause of acute illness on August 30, 2000, among patients at an outpatient dialysis center (center A). DESIGN We performed a cohort study of all patients receiving dialysis on August 30, 2000; reviewed dialysis procedures; and analyzed dialysis water samples using microbiologic and chemical assays. SETTING Dialysis center (center A). PATIENTS A case-patient was defined as a patient who developed chills within 5 hours after starting hemodialysis at center A on August 30, 2000. RESULTS Sixteen (36%) of 44 patients at center A met the case definition. All case-patients were hospitalized; 2 died. Besides chills, 15 (94%) of the case-patients experienced nausea; 12 (75%), vomiting; and 4 (25%), fever. Illness was more frequent on the second than the first dialysis shift (16 of 20 vs 0 of 24, P < .001); no other risk factors were identified. The centers water treatment system had received inadequate maintenance and disinfection and a sulfurous odor was noted during sampling of the water from the reverse osmosis (RO) unit. The water had elevated bacterial counts. Volatile sulfur-containing compounds (ie, methanethiol, carbon disulfide, dimethyldisulfide, and sulfur dioxide) were detected by gas chromatography and mass spectrometry in 8 of 12 water samples from the RO unit and in 0 of 28 samples from other areas (P < .001). Results of tests for heavy metals and chloramines were within normal limits. CONCLUSIONS Parenteral exposure to volatile sulfur-containing compounds, produced under anaerobic conditions in the RO unit, could have caused the outbreak. This investigation demonstrates the importance of appropriate disinfection and maintenance of water treatment systems in hemodialysis centers.

Deaths in International Travelers Arriving in the United States, July 1, 2005 to June 30, 2008

BACKGROUND The Centers for Disease Control and Preventions (CDC) Quarantine Activity Reporting System (QARS), which documents reports of morbidity and mortality among travelers, was analyzed to describe the epidemiology of deaths during international travel. METHODS We analyzed travel-related deaths reported to CDC from July 1, 2005 to June 30, 2008, in which international travelers died (1) on a U.S.-bound conveyance, or (2) within 72 hours after arriving in the United States, or (3) at any time after arriving in the United States from an illness possibly acquired during international travel. We analyzed age, sex, mode of travel (eg, by air, sea, land), date, and cause of death, and estimated rates using generalized linear models. RESULTS We identified 213 deaths. The median age of deceased travelers was 66 years (range 1-95); 65% were male. Most deaths (62%) were associated with sea travel; of these, 111 (85%) occurred in cruise ship passengers and 20 (15%) among cargo and cruise ship crew members. Of 81 air travel-associated deaths, 77 occurred in passengers, 3 among air ambulance patients, and 1 in a stowaway. One death was associated with land travel. Deaths were categorized as cardiovascular (70%), infectious disease (12%), cancer (6%), unintentional injury (4%), intentional injury (1%), and other (7%). Of 145 cardiovascular deaths with reported ages, 62% were in persons 65 years of age and older. Nineteen (73%) of 26 persons who died from infectious diseases had chronic medical conditions. There was significant seasonal variation (lowest in July-September) in cardiovascular mortality in cruise ship passengers. CONCLUSIONS Cardiovascular conditions were the major cause of death for both sexes. Travelers should seek pre-travel medical consultation, including guidance on preventing cardiovascular events, infections, and injuries. Persons with chronic medical conditions and the elderly should promptly seek medical care if they become ill during travel.

Border Lookout: Enhancing Tuberculosis Control on the United States-Mexico Border.

We evaluated the use of federal public health intervention tools known as the Do Not Board and Border Lookout (BL) for detecting and referring infectious or potentially infectious land border travelers with tuberculosis (TB) back to treatment. We used data about the issuance of BL from April 2007 to September 2013 to examine demographics and TB laboratory results for persons on the list (N = 66) and time on the list before being located and achieving noninfectious status. The majority of case-patients were Hispanic and male, with a median age of 39 years. Most were citizens of the United States or Mexico, and 30.3% were undocumented migrants. One-fifth had multidrug-resistant TB. Nearly two-thirds of case-patients were located and treated as a result of being placed on the list. However, 25.8% of case-patients, primarily undocumented migrants, remain lost to follow-up and remain on the list. For this highly mobile patient population, the use of this novel federal travel intervention tool facilitated the detection and treatment of infectious TB cases that were lost to follow-up.

Tracing Airline Travelers for a Public Health Investigation Middle East Respiratory Syndrome Coronavirus (MERS-CoV) Infection in the United States, 2014

Objective. CDC routinely conducts contact investigations involving travelers on commercial conveyances, such as aircrafts, cargo vessels, and cruise ships. Methods. The agency used established systems of communication and partnerships with other federal agencies to quickly provide accurate traveler contact information to states and jurisdictions to alert contacts of potential exposure to two travelers with Middle East Respiratory Syndrome Coronavirus (MERS-CoV) who had entered the United States on commercial flights in April and May 2014. Results. Applying the same process used to trace and notify travelers during routine investigations, such as those for tuberculosis or measles, CDC was able to notify most travelers of their potential exposure to MERS-CoV during the first few days of each investigation. Conclusion. To prevent the introduction and spread of newly emerging infectious diseases, travelers need to be located and contacted quickly.

US Federal Travel Restrictions for Persons with Higher-Risk Exposures to Communicable Diseases of Public Health Concern

Published guidance recommends controlled movement for persons with higher-risk exposures (HREs) to communicable diseases of public health concern; US federal public health travel restrictions (PHTRs) might be implemented to enforce these measures. We describe persons eligible for and placed on PHTRs because of HREs during 2014–2016. There were 160 persons placed on PHTRs: 142 (89%) involved exposure to Ebola virus, 16 (10%) to Lassa fever virus, and 2 (1%) to Middle East respiratory syndrome coronavirus. Most (90%) HREs were related to an epidemic. No persons attempted to travel; all persons had PHTRs lifted after completion of a maximum disease-specific incubation period or a revised exposure risk classification. PHTR enforced controlled movement and removed risk for disease transmission among travelers who had contacts who refused to comply with public health recommendations. PHTRs are mechanisms to mitigate spread of communicable diseases and might be critical in enhancing health security during epidemics.

Conveyance Contact Investigation for Imported Middle East Respiratory Syndrome Cases, United States, May 2014

In 2014, the Centers for Disease Control and Prevention conducted conveyance contact investigations for 2 Middle East respiratory syndrome cases imported into the United States, comprising all passengers and crew on 4 international and domestic flights and 1 bus. Of 655 contacts, 78% were interviewed; 33% had serologic testing. No secondary cases were identified.