Christina R. Phares

Epidemiology of Invasive Group B Streptococcal Disease in the United States, 1999-2005

CONTEXT Group B streptococcus is a leading infectious cause of morbidity in newborns and causes substantial disease in elderly individuals. Guidelines for prevention of perinatal disease through intrapartum chemoprophylaxis were revised in 2002. Candidate vaccines are under development. OBJECTIVE To describe disease trends among populations that might benefit from vaccination and among newborns during a period of evolving prevention strategies. DESIGN AND SETTING Analysis of active, population-based surveillance in 10 states participating in the Active Bacterial Core surveillance/Emerging Infections Program Network. MAIN OUTCOME MEASURES Age- and race-specific incidence of invasive group B streptococcal disease. RESULTS There were 14,573 cases of invasive group B streptococcal disease during 1999-2005, including 1348 deaths. The incidence of invasive group B streptococcal disease among infants from birth through 6 days decreased from 0.47 per 1000 live births in 1999-2001 to 0.34 per 1000 live births in 2003-2005 (P < .001), a relative reduction of 27% (95% confidence interval [CI], 16%-37%). Incidence remained stable among infants aged 7 through 89 days (mean, 0.34 per 1000 live births) and pregnant women (mean, 0.12 per 1000 live births). Among persons aged 15 through 64 years, disease incidence increased from 3.4 per 100,000 population in 1999 to 5.0 per 100,000 in 2005 (chi2(1) for trend, 57; P < .001), a relative increase of 48% (95% CI, 32%-65%). Among adults 65 years or older, incidence increased from 21.5 per 100,000 to 26.0 per 100,000 (chi2(1) for trend, 15; P < .001), a relative increase of 20% (95% CI, 8%-35%). All 4882 isolates tested were susceptible to penicillin, ampicillin, and vancomycin, but 32% and 15% were resistant to erythromycin and clindamycin, respectively. Serotypes Ia, Ib, II, III, and V accounted for 96% of neonatal cases and 88% of adult cases. CONCLUSIONS Among infants from birth through 6 days, the incidence of group B streptococcal disease was lower in 2003-2005 relative to 1999-2001. This reduction coincided with the release of revised disease prevention guidelines in 2002. However, the disease burden in adults is substantial and increased significantly during the study period.

Epidemiology of Severe Pneumonia Caused by Legionella longbeachae, Mycoplasma pneumoniae, and Chlamydia pneumoniae: 1-Year, Population-Based Surveillance for Severe Pneumonia in Thailand

BACKGROUND Legionella species, Mycoplasma pneumoniae, and Chlamydia pneumoniae are recognized as important causes of pneumonia in high-income countries, but their significance in middle-income countries, such as Thailand, is unknown. METHODS Population-based surveillance identified inpatient 3489 cases of clinically-defined pneumonia in a rural Thai province for 1 year. Patients who had a chest radiograph performed (for 2059 cases of pneumonia) were enrolled in an etiology study (which included 755 cases of pneumonia among 738 patients). Paired serum, nasopharyngeal swab, and urine specimens were obtained for diagnostic immunologic and molecular tests. Patients aged <18 years were not systematically tested for Legionella species. We report a lower limit of incidence (observed incidence) and an upper limit extrapolated to persons not tested or not enrolled in the study. RESULTS The incidence of pneumonia due to Legionella longbeachae requiring hospitalization was 5-29 cases per 100,000 population. No case of Legionella pneumophila pneumonia was observed. The definite C. pneumoniae pneumonia incidence was 3-23 cases per 100,000 population; rates were highest among patients aged <1 year (18-166 cases per 100,000 population) and those aged >or=70 years (23-201 cases per 100,000 population). M. pneumoniae pneumonia had a similar age distribution, with an overall incidence of 6-44 cases per 100,000 population. These pathogens were associated with 15% of all cases of pneumonia. A nonsignificantly higher proportion of patients with pneumonia associated with L. longbeachae, compared with patients with pneumonia associated with M. pneumoniae or C. pneumoniae, required supplemental oxygen or mechanical ventilation (45% vs. 18%; P<.1). Among patients with atypical pneumonia, only 15% received antibiotics with activity against the associated pathogen. CONCLUSION M. pneumoniae, C. pneumoniae, and L. longbeachae, but not L. pneumophila, are frequently associated with severe pneumonia in rural Thailand. Few patients receive antibiotics that cover atypical pathogens.

Albendazole Therapy and Enteric Parasites in United States–Bound Refugees

BACKGROUND Beginning on May 1, 1999, the Centers for Disease Control and Prevention (CDC) recommended presumptive treatment of refugees for intestinal parasites with a single dose of albendazole (600 mg), administered overseas before departure for the United States. METHODS We conducted a retrospective cohort study involving 26,956 African and Southeast Asian refugees who were screened by means of microscopical examination of stool specimens for intestinal parasites on resettlement in Minnesota between 1993 and 2007. Adjusted prevalence ratios for intestinal nematodes, schistosoma species, giardia, and entamoeba were calculated among refugees who migrated before versus those who migrated after the CDC recommendation of presumptive predeparture albendazole treatment. RESULTS Among 4370 untreated refugees, 20.8% had at least one stool nematode, most commonly hookworm (in 9.2%). Among 22,586 albendazole-treated refugees, only 4.7% had one or more nematodes, most commonly trichuris (in 3.9%). After adjustment for sex, age, and region, albendazole-treated refugees were less likely than untreated refugees to have any nematodes (prevalence ratio, 0.19), ascaris (prevalence ratio, 0.06), hookworm (prevalence ratio, 0.07), or trichuris (prevalence ratio, 0.27) but were not less likely to have giardia or entamoeba. Schistosoma ova were identified exclusively among African refugees and were less prevalent among those treated with albendazole (prevalence ratio, 0.60). After implementation of the albendazole protocol, the most common pathogens among 17,011 African refugees were giardia (in 5.7%), trichuris (in 5.0%), and schistosoma (in 1.8%); among 5575 Southeast Asian refugees, only giardia remained highly prevalent (present in 17.2%). No serious adverse events associated with albendazole use were reported. CONCLUSIONS Presumptive albendazole therapy administered overseas before departure for the United States was associated with a decrease in the prevalence of intestinal nematodes among newly arrived African and Southeast Asian refugees.

Fluid Intake and Decreased Risk for Hospitalization for Dengue Fever, Nicaragua

In a hospital and health center-based study in Nicaragua, fluid intake during the 24 hours before being seen by a clinician was statistically associated with decreased risk for hospitalization of dengue fever patients. Similar results were obtained for children <15 years of age and older adolescents and adults in independent analyses.

Non-Pharmaceutical Interventions during an Outbreak of 2009 Pandemic Influenza A (H1N1) Virus Infection at a Large Public University, April–May 2009

Nonpharmaceutical interventions (NPIs), such as home isolation, social distancing, and infection control measures, are recommended by public health agencies as strategies to mitigate transmission during influenza pandemics. However, NPI implementation has rarely been studied in large populations. During an outbreak of 2009 Pandemic Influenza A (H1N1) virus infection at a large public university in April 2009, an online survey was conducted among students, faculty, and staff to assess knowledge of and adherence to university-recommended NPI. Although 3924 (65%) of 6049 student respondents and 1057 (74%) of 1401 faculty respondents reported increased use of self-protective NPI, such as hand washing, only 27 (6.4%) of 423 students and 5 (8.6%) of 58 faculty with acute respiratory infection (ARI) reported staying home while ill. Nearly one-half (46%) of student respondents, including 44.7% of those with ARI, attended social events. Results indicate a need for efforts to increase compliance with home isolation and social distancing measures.

Mass vaccination with a two-dose oral cholera vaccine in a long-standing refugee camp, Thailand

BACKGROUND During 2005-2012, surveillance in Maela refugee camp, Thailand, identified four cholera outbreaks, with rates up to 10.7 cases per 1000 refugees. In 2013, the Thailand Ministry of Public Health sponsored a two-dose oral cholera vaccine (OCV) campaign for the approximately 46,000 refugees living in Maela. METHODS We enumerated the target population (refugees living in Maela who are ≥1 year old and not pregnant) in a census three months before the campaign and issued barcoded OCV cards to each individual. We conducted the campaign using a fixed-post strategy during two eight-day rounds plus one two-day round for persons who had missed their second dose and recorded vaccine status for each individual. To identify factors associated with no vaccination (versus at least one dose) and those associated with adverse events following immunization (AEFI), we used separate marginal log-binomial regression models with robust variance estimates to account for household clustering. RESULTS A total of 63,057 OCV doses were administered to a target population of 43,485 refugees. An estimated 35,399 (81%) refugees received at least one dose and 27,658 (64%) received two doses. A total of 993 additional doses (1.5%) were wasted including 297 that were spat out. Only 0.05% of refugees, mostly children, could not be vaccinated due to repeated spitting. Characteristics associated with no vaccination (versus at least one dose) included age ≥15 years (versus 1-14 years), Karen ethnicity (versus any other ethnicity) and, only among adults 15-64 years old, male sex. Passive surveillance identified 84 refugees who experienced 108 AEFI including three serious but coincidental events. The most frequent AEFI were nausea (49%), dizziness (38%), and fever (30%). Overall, AEFI were more prevalent among young children and older adults. CONCLUSIONS Our results suggest that mass vaccination in refugee camps with a two-dose OCV is readily achievable and AEFI are few.

Prevention of mother-to-child transmission of infections during pregnancy: implementation of recommended interventions, United States, 2003–2004

OBJECTIVE The objective of the study was to describe prenatal screening, positive test rates, and the administration of indicated interventions for hepatitis B, rubella, syphilis, group B streptococcus (GBS), chlamydia, and gonorrhea in the United States using 2 population-based surveys. STUDY DESIGN Both surveys abstracted demographic, prenatal, and delivery data from a representative sample of delivering women in 10 states. Analyses accounted for the complex sampling design. RESULTS Among the 7691 and 19,791 women in the 2 studies, screened proportions before delivery were more than 90% for hepatitis B and rubella, 80% for syphilis, 72-85% for GBS, and less than 80% for chlamydia and gonorrhea. Inadequate prenatal care was the strongest factor associated with no screening. Administration of interventions indicated by positive test results was variable but generally low. CONCLUSION Improved prenatal screening and administration of indicated treatments or interventions, particularly for syphilis, GBS, chlamydia, and gonorrhea, will further protect newborns from infection.

Taeniasis among Refugees Living on Thailand-Myanmar Border, 2012.

We tested refugee camp residents on the Thailand–Myanmar border for Taenia solium infection. Taeniasis prevalence was consistent with that for other disease-endemic regions, but seropositivity indicating T. solium taeniasis was rare. Seropositivity indicating cysticercosis was 5.5% in humans, and 3.2% in pigs. Corralling pigs and providing latrines may control transmission of these tapeworms within this camp.

Presumptive Treatment to Reduce Imported Malaria among Refugees from East Africa Resettling in the United States

During May 4, 2007-February 29, 2008, the United States resettled 6,159 refugees from Tanzania. Refugees received pre-departure antimalarial treatment with sulfadoxine-pyrimethamine (SP), partially supervised (three/six doses) artemether-lumefantrine (AL), or fully supervised AL. Thirty-nine malaria cases were detected. Disease incidence was 15.5/1,000 in the SP group and 3.2/1,000 in the partially supervised AL group (relative change = -79%, 95% confidence interval = -56% to -90%). Incidence was 1.3/1,000 refugees in the fully supervised AL group (relative change = -92% compared with SP group; 95% confidence interval = -66% to -98%). Among 39 cases, 28 (72%) were in refugees < 15 years of age. Time between arrival and symptom onset (median = 14 days, range = 3-46 days) did not differ by group. Thirty-two (82%) persons were hospitalized, 4 (10%) had severe manifestations, and 9 (27%) had parasitemias > 5% (range = < 0.1-18%). Pre-departure presumptive treatment with an effective drug is associated with decreased disease among refugees.

Association of Diabetes and Tuberculosis Disease among US-Bound Adult Refugees, 2009–2014

Diabetes is associated with an increased risk for active tuberculosis (TB) disease. We conducted a case–control study and found a significant association between diabetes and TB disease among US-bound refugees. These findings underscore the value of collaborative management of both diseases.