Sara A. Lowther

Human parainfluenza virus-associated hospitalizations among children less than five years of age in the United States.

Background. Human parainfluenza viruses 1 through 3 (HPIV-1–3) are important causes of respiratory tract infections in young children. This study sought to provide current estimates of HPIV-1–3-associated hospitalizations among US children. Methods. Hospitalizations for bronchiolitis, bronchitis, croup and pneumonia among children age <5 years were determined for the years 1979 through 1997 using the National Hospital Discharge Survey. Average annual hospitalizations during the last 4 years of the study for each of these four diseases were multiplied by the proportions of each disease associated with HPIV-1–3 infection (as previously reported in hospital-based studies) to estimate hospitalizations potentially associated with HPIV-1–3 infections. Seasonal trends in HPIV-1–3-associated hospitalizations were compared with HPIV detections in the National Respiratory and Enteric Virus Surveillance System, which prospectively monitors respiratory viral detections throughout the United States. Results. The proportions of hospitalizations associated with HPIV infection for each disease varied widely in the 6 hospital-based studies we selected. Consequently our annual estimated rates of hospitalization were broad: HPIV-1, 0.32 to 1.59 per 1000 children; HPIV-2, 0.10 to 0.86 per 1000 children; and HPIV-3, 0.48 to 2.6 per 1000 children. Based on these data HPIV-1 may account for 5800 to 28 900 annual hospitalizations; HPIV-2 for 1800 to 15 600 hospitalizations; and HPIV-3 for 8700 to 52 000 hospitalizations. Conclusions. We provide broad, serotype-specific estimates of US childhood hospitalizations associated with HPIV infections. More precise estimates of HPIV-associated hospitalizations would require large prospective studies of HPIV-associated diseases by more sensitive viral testing methods, such as polymerase chain reaction techniques.

Bronchiolitis-associated hospitalizations among American Indian and Alaska Native children.

BACKGROUND Respiratory syncytial virus (RSV) is the leading cause of lower respiratory tract illness among infants and young children. Respiratory system diseases account for a large proportion of hospitalizations in American Indian and Alaska Native (AI/AN) children; however, aggregate estimates of RSV-associated hospitalizations among AI/AN children have not been made. METHODS We used Indian Health Service hospitalization data from 1990 through 1995 to describe hospitalizations associated with bronchiolitis, the most characteristic clinical manifestation of RSV infection, among AI/AN children <5 years old. RESULTS The overall bronchiolitis-associated hospitalization rate among AI/AN infants < 1 year old was considerably higher (61.8 per 1,000) than the 1995 estimated bronchiolitis hospitalization rate among all US infants (34.2 per 1,000). Hospitalization rates were higher among male infants (72.2 per 1,000) than among females infants (51.1 per 1,000). The highest infant hospitalization rate was noted in the Navajo Area (96.3 per 1,000). Hospitalizations peaked annually in January or February, consistent with national peaks for RSV detection. Bronchiolitis hospitalizations accounted for an increasing proportion of hospitalizations for lower respiratory tract illnesses. CONCLUSIONS Bronchiolitis-associated hospitalization rates are substantially greater for AI/AN infants than those for all US infants. This difference may reflect an increased likelihood of severe RSV-associated disease or a decreased threshold for hospitalization among AI/AN infants with bronchiolitis compared with all US infants. AI/AN children would receive considerable benefit from lower respiratory tract illness prevention programs, including an RSV vaccine, if and when one becomes available.

Multidrug-Resistant Typhoid Fever With Neurologic Findings on the Malawi-Mozambique Border

BACKGROUND Salmonella enterica serovar Typhi causes an estimated 22 million cases of typhoid fever and 216 000 deaths annually worldwide. We investigated an outbreak of unexplained febrile illnesses with neurologic findings, determined to be typhoid fever, along the Malawi-Mozambique border. METHODS The investigation included active surveillance, interviews, examinations of ill and convalescent persons, medical chart reviews, and laboratory testing. Classification as a suspected case required fever and ≥1 other finding (eg, headache or abdominal pain); a probable case required fever and a positive rapid immunoglobulin M antibody test for typhoid (TUBEX TF); a confirmed case required isolation of Salmonella Typhi from blood or stool. Isolates underwent antimicrobial susceptibility testing and subtyping by pulsed-field gel electrophoresis (PFGE). RESULTS We identified 303 cases from 18 villages with onset during March-November 2009; 214 were suspected, 43 were probable, and 46 were confirmed cases. Forty patients presented with focal neurologic abnormalities, including a constellation of upper motor neuron signs (n = 19), ataxia (n = 22), and parkinsonism (n = 8). Eleven patients died. All 42 isolates tested were resistant to ampicillin, chloramphenicol, and trimethoprim-sulfamethoxazole; 4 were also resistant to nalidixic acid. Thirty-five of 42 isolates were indistinguishable by PFGE. CONCLUSIONS The unusual neurologic manifestations posed a diagnostic challenge that was resolved through rapid typhoid antibody testing in the field and subsequent blood culture confirmation in the Malawi national reference laboratory. Extending laboratory diagnostic capacity, including blood culture, to populations at risk for typhoid fever in Africa will improve outbreak detection, response, and clinical treatment.

Entamoeba histolytica/Entamoeba dispar Infections in Human Immunodeficiency Virus-Infected Patients in the United States

We describe the incidence of and laboratory and clinical characteristics associated with Entamoeba histolytica/Entamoeba dispar infection diagnosed in human immunodeficiency virus (HIV)-infected persons enrolled in the Adult and Adolescent Spectrum of HIV Disease Project. From 1 January 1990 to 1 January 1998 (82, 518 person-years of follow-up), 111 patients (98% men) were diagnosed with E. histolytica/E. dispar infection. Among HIV-infected patients in the United States, the incidence of diagnosed E. histolytica disease is low (13.5 cases per 10,000 person-years [95% confidence interval, 7.7-22.2], with diagnosis most common in those patients exposed to HIV through male-male sex.

Environmental Surveillance for Polioviruses in the Global Polio Eradication Initiative

This article summarizes the status of environmental surveillance (ES) used by the Global Polio Eradication Initiative, provides the rationale for ES, gives examples of ES methods and findings, and summarizes how these data are used to achieve poliovirus eradication. ES complements clinical acute flaccid paralysis (AFP) surveillance for possible polio cases. ES detects poliovirus circulation in environmental sewage and is used to monitor transmission in communities. If detected, the genetic sequences of polioviruses isolated from ES are compared with those of isolates from clinical cases to evaluate the relationships among viruses. To evaluate poliovirus transmission, ES programs must be developed in a manner that is sensitive, with sufficiently frequent sampling, appropriate isolation methods, and specifically targeted sampling sites in locations at highest risk for poliovirus transmission. After poliovirus ceased to be detected in human cases, ES documented the absence of endemic WPV transmission and detected imported WPV. ES provides valuable information, particularly in high-density populations where AFP surveillance is of poor quality, persistent virus circulation is suspected, or frequent virus reintroduction is perceived. Given the benefits of ES, GPEI plans to continue and expand ES as part of its strategic plan and as a supplement to AFP surveillance.

Evaluation of New Biomarker Genes for Differentiating Haemophilus influenzae from Haemophilus haemolyticus

ABSTRACT PCR detecting the protein D (hpd) and fuculose kinase (fucK) genes showed high sensitivity and specificity for identifying Haemophilus influenzae and differentiating it from H. haemolyticus. Phylogenetic analysis using the 16S rRNA gene demonstrated two distinct groups for H. influenzae and H. haemolyticus.

World Health Organization regional assessments of the risks of poliovirus outbreaks.

While global polio eradication requires tremendous efforts in countries where wild polioviruses (WPVs) circulate, numerous outbreaks have occurred following WPV importation into previously polio-free countries. Countries that have interrupted endemic WPV transmission should continue to conduct routine risk assessments and implement mitigation activities to maintain their polio-free status as long as wild poliovirus circulates anywhere in the world. This article reviews the methods used by World Health Organization (WHO) regional offices to qualitatively assess risk of WPV outbreaks following an importation. We describe the strengths and weaknesses of various risk assessment approaches, and opportunities to harmonize approaches. These qualitative assessments broadly categorize risk as high, medium, or low using available national information related to susceptibility, the ability to rapidly detect WPV, and other population or program factors that influence transmission, which the regions characterize using polio vaccination coverage, surveillance data, and other indicators (e.g., sanitation), respectively. Data quality and adequacy represent a challenge in all regions. WHO regions differ with respect to the methods, processes, cut-off values, and weighting used, which limits comparisons of risk assessment results among regions. Ongoing evaluation of indicators within regions and further harmonization of methods between regions are needed to effectively plan risk mitigation activities in a setting of finite resources for funding and continued WPV circulation.

Risk of severe acute respiratory syndrome-associated coronavirus transmission aboard commercial aircraft.

Abstract Background Severe acute respiratory syndrome–associated coronavirus (SARS‐CoV) was introduced to the United States through air travel. Although the risk of SARS‐CoV transmission within aircraft cabins has been addressed by several studies, the magnitude of the risk remains unclear. Methods We attempted to contact all persons with working US telephone numbers aboard seven US‐bound flights carrying SARS patients. Consenting participants responded to a questionnaire, and a serum sample was collected at least 38 days after the flight and tested for SARS‐CoV‐associated antibodies. Participants reporting an illness compatible with SARS, with onset during the 2‐ to 10‐day incubation period, were considered suspect cases; positive serology was required for confirmed cases. Results Among 1,766 passengers and crew, 339 (19%) persons were contacted. Of these, 312 (92%) completed questionnaires, and blood was collected from 127 (37%). Serology was negative for all 127 participants, including three of four who met the clinical case criteria for SARS, and the fourth had a mild illness that lasted only 5 days. Conclusions Transmission of SARS‐associated CoV was not observed, suggesting that the risk of transmission is not amplified aboard aircraft.

SARS and Pregnancy: A Case Report

We report a laboratory-confirmed case of severe acute respiratory syndrome (SARS) in a pregnant woman. Although the patient had respiratory failure, a healthy infant was subsequently delivered, and the mother is now well. There was no evidence of viral shedding at delivery. Antibodies to SARS virus were detected in cord blood and breast milk.

SARS-associated Coronavirus Transmission, United States

To better assess the risk for transmission of the severe acute respiratory syndrome–associated coronavirus (SARS-CoV), we obtained serial specimens and clinical and exposure data from seven confirmed U.S. SARS patients and their 10 household contacts. SARS-CoV was detected in a day-14 sputum specimen from one case-patient and in five stool specimens from two case-patients. In one case-patient, SARS-CoV persisted in stool for at least 26 days after symptom onset. The highest amounts of virus were in the day-14 sputum sample and a day-14 stool sample. Residual respiratory symptoms were still present in recovered SARS case-patients 2 months after illness onset. Possible transmission of SARS-CoV occurred in one household contact, but this person had also traveled to a SARS-affected area. The data suggest that SARS-CoV is not always transmitted efficiently. Laboratory diagnosis of SARS-CoV infection is difficult; thus, sputum and stool specimens should be included in the diagnostic work-up for SARS-CoV infection.