Alternative Devices for Heart Rate Variability Measures: A Comparative Test-Retest Reliability Study.

Using healthy adult participants, seven measures of heart rate variability were obtained simultaneously from four devices in five behavioral conditions. Two devices were ECG-based and two utilized photoplethysmography. The 140 numerical values (measure, condition, device) are presented. The comparative operational reliability of the four devices was assessed, and it was found that the two ECG-base devices were more reliable than the photoplethysmographic devices. The interchangeability of devices was assessed by determining the between-device Limits of Agreement. Intraclass correlation coefficients were determined and used to calculate the standard error of measurement and the Minimal Detectable Difference. The Minimal Detectable Difference, MDD, quantifies the smallest statistically significant change in a measure and is therefore critical when HRV measures are used longitudinally to assess treatment response or disease progression.

NWChem: Past, present, and future.

Specialized computational chemistry packages have permanently reshaped the landscape of chemical and materials science by providing tools to support and guide experimental efforts and for the prediction of atomistic and electronic properties. In this regard, electronic structure packages have played a special role by using first-principle-driven methodologies to model complex chemical and materials processes. Over the past few decades, the rapid development of computing technologies and the tremendous increase in computational power have offered a unique chance to study complex transformations using sophisticated and predictive many-body techniques that describe correlated behavior of electrons in molecular and condensed phase systems at different levels of theory. In enabling these simulations, novel parallel algorithms have been able to take advantage of computational resources to address the polynomial scaling of electronic structure methods. In this paper, we briefly review the NWChem computational chemistry suite, including its history, design principles, parallel tools, current capabilities, outreach, and outlook.

Evolving Spinal Cord Stimulation Technologies and Clinical Implications in Chronic Pain Management.

PURPOSE OF REVIEW: Spinal cord stimulation (SCS), based on the gate theory of nociception, has been shown to be effective in the management of chronic pain conditions. While early-generation technology offered many patients improvement in their pain and symptoms, limitations including paresthesia, dependence on mapping, decreased chronological efficacy, and inadequate coverage left many patients with persistent pain and overt therapeutic failure. RECENT FINDINGS: New advances in neuromodulation technology circumvent many of these previous limitations and offer patients improved pain relief and quality of life. In this review, an update on recent technological developments in the field of SCS and peripheral neuromodulation is presented with discussion on differentiating characteristics which may help guide applicability to individual patient needs.

The NICU Parent Risk Evaluation and Engagement Model and Instrument (PREEMI) for neonates in intensive care units.

Engagement is a fairly new concept in practice and research and is gaining the interest of federal and private regulators, clinicians, and researchers. In this article, we offer a standard definition and outline an engagement model and an instrument for early prediction and identification of low engagement in at-risk parents of late preterm infants. The Parent Risk Evaluation and Engagement Model and Instrument (PREEMI), its theoretical underpinnings, instrument design, and practical application and future research are discussed.

Establishing breastfeeding with the late preterm infant in the NICU.

OBJECTIVE: To describe challenges that late preterm infants (LPIs) face with breastfeeding and to provide an overview of current policy statements and practice guidelines that support breastfeeding for LPIs. In addition, we describe current breastfeeding research related to the LPI and combine this research with policies and practice guidelines to provide evidence-based recommendations to guide practice and future research in the NICU. DATA SOURCES: Cumulative Index to Nursing and Allied Health Literature and PubMed databases. STUDY SELECTION: Policies, guidelines, and research relevant to breastfeeding the LPI were selected if they were published between January 1, 2009 and March 1, 2014. All documents were published in English and related to breastfeeding management or breastfeeding outcomes for the LPI. DATA EXTRACTION: Information from articles, policies, and guidelines were chosen for their relevance to breastfeeding the LPI. DATA SYNTHESIS: Policy statements and practice guidelines were reviewed to provide an understanding of breastfeeding recommendations for the LPI. Additionally, recent research studies were reviewed and combined with the policy statements and practice guidelines to provide practice recommendations for NICU providers. CONCLUSIONS: LPIs require a unique set of interventions for breastfeeding success; though they might be perceived as small, full-term infants, these infants often have greater challenges with breastfeeding than their term counterparts. Future research should be directed at identifying and testing specific strategies that will best support this at-risk population. Findings from this article are applicable for the LPI in the NICU as well as other care areas such as special care and transitional nurseries.

Routine delivery of artemisinin-based combination treatment at fixed health facilities reduces malaria prevalence in Tanzania: an observational study.

BACKGROUND: Artemisinin-based combination therapy (ACT) has been promoted as a means to reduce malaria transmission due to their ability to kill both asexual blood stages of malaria parasites, which sustain infections over long periods and the immature derived sexual stages responsible for infecting mosquitoes and onward transmission. Early studies reported a temporal association between ACT introduction and reduced malaria transmission in a number of ecological settings. However, these reports have come from areas with low to moderate malaria transmission, been confounded by the presence of other interventions or environmental changes that may have reduced malaria transmission, and have not included a comparison group without ACT. This report presents results from the first large-scale observational study to assess the impact of case management with ACT on population-level measures of malaria endemicity in an area with intense transmission where the benefits of effective infection clearance might be compromised by frequent and repeated re-infection. METHODS: A pre-post observational study with a non-randomized comparison group was conducted at two sites in Tanzania. Both sites used sulphadoxine-pyrimethamine (SP) monotherapy as a first-line anti-malarial from mid-2001 through 2002. In 2003, the ACT, artesunate (AS) co-administered with SP (AS + SP), was introduced in all fixed health facilities in the intervention site, including both public and registered non-governmental facilities. Population-level prevalence of Plasmodium falciparum asexual parasitaemia and gametocytaemia were assessed using light microscopy from samples collected during representative household surveys in 2001, 2002, 2004, 2005 and 2006. FINDINGS: Among 37,309 observations included in the analysis, annual asexual parasitaemia prevalence in persons of all ages ranged from 11% to 28% and gametocytaemia prevalence ranged from <1% to 2% between the two sites and across the five survey years. A multivariable logistic regression model was fitted to adjust for age, socioeconomic status, bed net use and rainfall. In the presence of consistently high coverage and efficacy of SP monotherapy and AS + SP in the comparison and intervention areas, the introduction of ACT in the intervention site was associated with a modest reduction in the adjusted asexual parasitaemia prevalence of 5 percentage-points or 23% (p < 0.0001) relative to the comparison site. Gametocytaemia prevalence did not differ significantly (p = 0.30). INTERPRETATION: The introduction of ACT at fixed health facilities only modestly reduced asexual parasitaemia prevalence. ACT is effective for treatment of uncomplicated malaria and should have substantial public health impact on morbidity and mortality, but is unlikely to reduce malaria transmission substantially in much of sub-Saharan Africa where individuals are rapidly re-infected.

Toxoplasmosis hospitalizations in the United States, 2008, and trends, 1993-2008.

BACKGROUND: Toxoplasmosis-related hospitalizations often occur in persons with human immunodeficiency virus (HIV) infection and other causes of immunosuppression. METHODS: Using the National Inpatient Sample (NIS) from the Healthcare Cost and Utilization Project, we examined trends in toxoplasmosis-related hospitalizations by HIV infection status from 1993 through 2008, and rates by sex and race or ethnicity in 2008. The NIS is designed to represent a 20% sample of US community hospitals and currently includes information on up to 8 million discharges per year from ∼1000 hospitals. We used International Classification of Diseases, Ninth Revision, Clinical Modification codes 130-130.9 for toxoplasmosis and 042-044/795.8/795.71/V08 for HIV infection. RESULTS: Estimated HIV-associated toxoplasmosis hospitalizations increased from 9395 in 1993 to 10583 in 1995 (P = .0002), then dropped to 3643 in 2001 (P < .0001), with similar levels thereafter. The rate of HIV-associated toxoplasmosis hospitalizations among all HIV-related hospitalizations decreased from 3.33% in 1993 to 1.25% in 2008 (P < .0001). Estimated non-HIV-associated toxoplasmosis hospitalizations were less variable from 1993 to 2008 (range, 386-819; 0.0020% in 1993, 0.0015% in 2008). In 2008, the rates of both HIV- and non-HIV-associated toxoplasmosis hospitalizations were higher in Hispanic persons than in white persons. CONCLUSIONS: HIV-associated toxoplasmosis hospitalizations dropped markedly after 1995 when highly active antiretroviral therapy was introduced; however, hospitalizations decreased relatively little after 2000, suggesting late diagnosis of some HIV-infected persons or antiretroviral therapy failure. Non-HIV-associated toxoplasmosis hospitalizations have been more stable. The rates of toxoplasmosis-related hospitalizations varied markedly among racial and ethnic groups.

Evaluation of antibacterial soap in the management of lymphoedema in Leogane, Haiti.

In areas endemic for lymphatic filariasis, progression of lymphoedema is associated with recurrent bacterial acute dermatolymphangioadenitis (ADLA). The role of antibacterial soap in preventing ADLA is unknown. In a randomized double-blinded clinical trial in Leogane, Haiti, lymphoedema patients washed affected legs with antibacterial (n = 97) or plain soap (n = 100). Reported ADLA incidence (by recall) before the study was 1.1 episodes per person-year, compared to 0.40 assessed during the 12-month study. ADLA incidence was significantly associated with age, illiteracy and lymphoedema stage, but not with soap type. Washing with soap, regardless of its antibacterial content, can help decrease ADLA incidence. (ClinicalTrials.gov identifier number NCT00139100.).

Source water quality effects on monochloramine inactivation of adenovirus, coxsackievirus, echovirus, and murine norovirus.

There is a need for more information regarding monochloramine disinfection efficacy for viruses in water. In this study, monochloramine disinfection efficacy was investigated for coxsackievirus B5 (CVB5), echovirus 11 (E11), murine norovirus (MNV), and human adenovirus 2 (HAdV2) in one untreated ground water and two partially treated surface waters. Duplicate disinfection experiments were completed at pH 7 and 8 in source water at concentrations of 1 and 3 mg/L monochloramine at 5 and 15 °C. The Efficiency Factor Hom (EFH) model was used to calculate CT values (mg-min/L) required to achieve 2-, 3-, and 4-log(10) reductions in viral titers. In all water types, monochloramine disinfection was most effective for MNV, with 3-log(10) CT values at 5 °C ranging from 27 to 110. Monochloramine disinfection was least effective for HAdV2 and E11, depending on water type, with 3-log(10) CT values at 5 °C ranging from 1200 to 3300 and 810 to 2300, respectively. Overall, disinfection proceeded faster at 15 °C and pH 7 for all water types. Inactivation of the study viruses was significantly different between water types, but there was no indication that overall disinfection efficacy was enhanced or inhibited in any one water type. CT values for HAdV2 in two types of source water exceeded federal CT value recommendations in the US. The results of this study demonstrate that water quality impacts the inactivation of viruses and should be considered when developing chloramination plans.

Causes of outbreaks associated with drinking water in the United States from 1971 to 2006.

Since 1971, the CDC, EPA, and Council of State and Territorial Epidemiologists (CSTE) have maintained the collaborative national Waterborne Disease and Outbreak Surveillance System (WBDOSS) to document waterborne disease outbreaks (WBDOs) reported by local, state, and territorial health departments. WBDOs were recently reclassified to better characterize water system deficiencies and risk factors; data were analyzed for trends in outbreak occurrence, etiologies, and deficiencies during 1971 to 2006. A total of 833 WBDOs, 577,991 cases of illness, and 106 deaths were reported during 1971 to 2006. Trends of public health significance include (i) a decrease in the number of reported outbreaks over time and in the annual proportion of outbreaks reported in public water systems, (ii) an increase in the annual proportion of outbreaks reported in individual water systems and in the proportion of outbreaks associated with premise plumbing deficiencies in public water systems, (iii) no change in the annual proportion of outbreaks associated with distribution system deficiencies or the use of untreated and improperly treated groundwater in public water systems, and (iv) the increasing importance of Legionella since its inclusion in WBDOSS in 2001. Data from WBDOSS have helped inform public health and regulatory responses. Additional resources for waterborne disease surveillance and outbreak detection are essential to improve our ability to monitor, detect, and prevent waterborne disease in the United States.

Effects of source water quality on chlorine inactivation of adenovirus, coxsackievirus, echovirus, and murine norovirus.

More information is needed on the disinfection efficacy of chlorine for viruses in source water. In this study, chlorine disinfection efficacy was investigated for USEPA Contaminant Candidate List viruses coxsackievirus B5 (CVB5), echovirus 1 (E1), murine norovirus (MNV), and human adenovirus 2 (HAdV2) in one untreated groundwater source and two partially treated surface waters. Disinfection experiments using pH 7 and 8 source water were carried out in duplicate, using 0.2 and 1 mg/liter free chlorine at 5 and 15 degrees C. The efficiency factor Hom (EFH) model was used to calculate disinfectant concentration x contact time (CT) values (mg x min/liter) required to achieve 2-, 3-, and 4-log(10) reductions in viral titers. In all water types, chlorine disinfection was most effective for MNV, with 3-log(10) CT values at 5 degrees C ranging from < or = 0.020 to 0.034. Chlorine disinfection was least effective for CVB5 in all water types, with 3-log(10) CT values at 5 degrees C ranging from 2.3 to 7.9. Overall, disinfection proceeded faster at 15 degrees C and pH 7 for all water types. Inactivation of the study viruses was significantly different between water types, but no single source water had consistently different inactivation rates than another. CT values for CVB5 in one type of source water exceeded the recommended CT values set forth by USEPA's Guidance Manual for Compliance with the Filtration and Disinfection Requirements for Public Water Systems using Surface Water Sources. The results of this study demonstrate that water quality plays a substantial role in the inactivation of viruses and should be considered when developing chlorination plans.

Development and evaluation of porcine cysticercosis QuickELISA in Triturus EIA analyzer.

We evaluated three diagnostic antigens (recombinant GP50, recombinant T24H, and synthetic Ts18var1) for cysticercosis and found that all three performed well in detecting cysticercosis in humans and pigs in several assay formats. These antigens were adapted to a new antibody detection format (QuickELISA). With one single incubation step which involves all reactants except the enzyme substrate, the QuickELISA is particularly suited for automation. We formatted the QuickELISA for the Triturus EIA analyzer for testing large numbers of samples. We found that in QuickELISA formats rGP50 and rT24H have better sensitivity and specificity than sTs18var1 for detecting porcine cysticercosis.

National outbreak of Acanthamoeba keratitis associated with use of a contact lens solution, United States.

An outbreak of Acanthamoeba keratitis, a rare, potentially blinding, corneal infection, was detected in the United States in 2007; cases had been increasing since 2004. A case-control study was conducted to investigate the outbreak. We interviewed 105 case-patients from 30 states and 184 controls matched geographically and by contact lens use. Available contact lenses, cases, solutions, and corneal specimens from case-patients were cultured and tested by molecular methods. In multivariate analyses, case-patients had significantly greater odds of having used Advanced Medical Optics Complete Moisture Plus (AMOCMP) solution (odds ratio 16.9, 95% confidence interval 4.8-59.5). AMOCMP manufacturing lot information was available for 22 case-patients, but none of the lots were identical. Three unopened bottles of AMOCMP tested negative for Acanthamoeba spp. Our findings suggest that the solution was not intrinsically contaminated and that its anti-Acanthamoeba efficacy was likely insufficient. Premarket standardized testing of contact lens solutions for activity against Acanthamoeba spp. is warranted.

Clinical malaria and sickle cell disease among multiple family members in Chicago, Illinois.

Malaria is a disease of global importance and accounts for up to 500 million cases per year. Nearly all malaria cases in the United States occur among persons who have traveled to areas with ongoing malaria transmission. Among the cases of malaria reported in the United States in 2000-2005, 695 were in US residents under the age of 18 years. The association of malaria with the sickle cell hemoglobin is well described in Africa but is a rare occurrence in the United States. Here we report 5 cases of Plasmodium falciparum malaria in siblings of a family who had traveled to Africa without taking chemoprophylaxis. Two of the children had sickle cell anemia, and 1 of them developed severe life-threatening malaria and hemolysis. The 3 other siblings had sickle cell trait, 2 of whom had complicated malaria. Patients who have sickle cell disease and are infected with malaria are prone to hyperhemolytic crisis; therefore, this complication should be anticipated. The patients we describe emphasize the significance of prompt recognition of malaria and comorbidities and institution of appropriate treatment. The importance of antimalarial prophylaxis should be communicated to parents of children who are traveling to endemic areas as part of routine child care.

Endpoints for lymphatic filariasis programs.

In 2000, annual mass administration of diethlycarbamazine and albendazole began in Leogane Commune, Haiti, to interrupt transmission of lymphatic filariasis (LF). After 5 years of treatment, microfilaremia, antigenemia, and mosquito infection rates were significantly reduced, but LF transmission was not interrupted. These finding have implications for other LF elimination programs.

Malaria surveillance - United States, 2005.

PROBLEM/CONDITION: Malaria in humans is caused by any of four species of intraerythrocytic protozoa of the genus Plasmodium (i.e., P. falciparum, P. vivax, P. ovale, or P. malariae). These parasites are transmitted by the bite of an infective female Anopheles sp. mosquito. The majority of malaria infections in the United States occur among persons who have traveled to or from areas with ongoing malaria transmission. In the United States, cases can occur through exposure to infected blood products, congenital transmission, or local mosquitoborne transmission. Malaria surveillance is conducted to identify episodes of local transmission and to guide prevention recommendations for travelers. PERIOD COVERED: This report summarizes cases in persons with onset of illness in 2005 and summarizes trends during previous years. DESCRIPTION OF SYSTEM: Malaria cases confirmed by blood film or polymerase chain reaction (PCR) are mandated to be reported to local and state health departments by health-care providers or laboratory staff. Case investigations are conducted by local and state health departments, and reports are transmitted to CDC through the National Malaria Surveillance System (NMSS). Data from NMSS serve as the basis for this report. RESULTS: CDC received reports of 1,528 cases of malaria, including seven fatal cases, with an onset of symptoms in 2005 among persons in the United States or one of its territories. This number represents an increase of 15.4% from the 1,324 cases reported for 2004. P. falciparum, P. vivax, P. malariae, and P. ovale were identified in 48.6%, 22.1%, 3.5%, and 2.5% of cases, respectively. Twelve patients (0.8% of total) were infected by two or more species. The infecting species was unreported or undetermined in 22.6% of cases. Compared with 2004, the largest increases in cases came from the Americas (23.1%; n = 213) and Asia and the Middle East (18.6%; n = 204). On the basis of estimated volume of travel, the highest estimated case rates of malaria among travelers occurred among those returning from West Africa. Of 870 U.S. civilians who acquired malaria abroad, only 160 (18.4%) reported that they had followed a chemoprophylactic drug regimen recommended by CDC for the area to which they had traveled. Two patients became infected in the United States, both attributed to congenital transmission; both were infected with P. vivax. Seven deaths were attributed to malaria, all caused by infection with P. falciparum. INTERPRETATION: The 15.4% increase in malaria cases in 2005, compared with 2004, resulted primarily from increases in the number of cases reported from Asia and the Middle East and from the Americas. This increase might in part reflect more complete reporting and in part increased travel to malarious areas. No change was noted in proportions of cases from other areas of the world, or in species responsible for the infection. In the majority of reported cases, U.S. civilians who acquired infection abroad had not adhered to a chemoprophylaxis regimen that was appropriate for the country in which they acquired malaria. U.S. civilians who traveled to West Africa had the highest estimated relative case rate. PUBLIC HEALTH ACTIONS: Additional investigations were conducted for the seven fatal cases and two infections acquired in the United States. Persons traveling to a malarious area should take one of the recommended chemoprophylaxis regimens appropriate for the region of travel and use personal protection measures to prevent mosquito bites. Any person who has been to a malarious area and who subsequently has a fever or influenza-like symptoms should seek medical care immediately and report their travel history to the clinician; investigation should include at least one blood-film test for malaria. Malaria infections can be fatal if not diagnosed and treated promptly. Recommendations concerning malaria prevention can be obtained from CDC at http://www.cdc.gov/travel or by calling the Malaria Hotline (telephone 770-488-7788). Recommendations for malaria treatment can be obtained at http://www.cdc.gov/malaria/diagnosis_treatment/treatment.htm or by calling the Malaria Hotline.

A simple method for collecting measured whole blood with quantitative recovery of antibody activities for serological surveys.

Compliance and acceptance for the finger-prick method of blood collection is generally better than for venipuncture. A finger-prick method of blood collection with quantitative antibody recovery is even more important for seroepidemiological surveys. Finger-prick blood collected and dried onto filter paper has been used; but, unfortunately, this method has several disadvantages, including loss of antibody activity, possible contact contamination from blood spots on adjacent filter papers, and difficulties in extracting antibodies, justifying the search for other methods of collecting and transporting blood samples. We report on a simple method of collecting a measured amount of finger-prick blood onto a sample pad, which is immediately transferred to storage/extraction buffer. The diluted blood sample is never dried, and because of the storage buffer, can be transported and stored without refrigeration. Furthermore, the diluted blood samples can then be tested directly without further preparation. We systematically compared several storage/extraction buffers and commercially available filter papers. We showed that antibody recovery was not significantly affected by the type of filter papers used but was significantly affected by the storage/extraction buffer used. The best such buffer is StabilZyme Select.

Recently acquired Toxoplasma gondii infection, Brazil.

The city of Erechim, Brazil, has a 17% prevalence of ocular toxoplasmosis, and type 1 Toxoplasma gondii predominates. To examine risk factors for acute T. gondii infection in this area, we administered a questionnaire to recently infected persons (n = 131) and seronegative controls (n = 110). Eating undercooked meat; having a garden; working in the garden or yard more than once per week; eating rare meat; eating cured, dried, or smoked meat; eating frozen lamb; and being male increased risk for T. gondii infection in univariate analysis. Risk factors independently associated with acute T. gondii infection in multivariate analysis were working in the garden (odds ratio [OR] 2.35, 95% confidence interval [CI] 1.27-4.33) and eating frozen lamb (OR 2.06, 95% CI 1.15-3.67). Among women (n = 86), having had children markedly increased the risk for T. gondii infection (OR 14.94, 95% CI 3.68-60.73).

Malaria surveillance--United States, 2004.

PROBLEM/CONDITION: Malaria in humans is caused by any of four species of intraerythrocytic protozoa of the genus Plasmodium (i.e., P. falciparum, P. vivax, P. ovale, or P. malariae). These parasites are transmitted by the bite of an infective female Anopheles sp. mosquito. The majority of malaria infections in the United States occur among persons who have traveled to areas with ongoing malaria transmission. In the United States, cases can occur through exposure to infected blood products, congenital transmission, or local mosquitoborne transmission. Malaria surveillance is conducted to identify episodes of local transmission and to guide prevention recommendations for travelers. PERIOD COVERED: This report summarizes cases in persons with onset of illness in 2004 and summarizes trends during previous years. DESCRIPTION OF SYSTEM: Malaria cases confirmed by blood film are mandated to be reported to local and state health departments by health-care providers or laboratory staff. Case investigations are conducted by local and state health departments, and reports are transmitted to CDC through the National Malaria Surveillance System (NMSS). Data from NMSS serve as the basis for this report. RESULTS: CDC received reports of 1,324 cases of malaria, including four fatal cases, with an onset of symptoms in 2004 among persons in the United States or one of its territories. This number represents an increase of 3.6% from the 1,278 cases reported for 2003. P. falciparum, P. vivax, P. malariae, and P. ovale were identified in 49.6%, 23.8%, 3.6%, and 2.0% of cases, respectively. Seventeen patients (1.3% of total) were infected by two or more species. The infecting species was unreported or undetermined in 262 (19.8%) cases. Compared with 2003, the number of reported malaria cases acquired in the Americas (n = 173) increased 17.7%, whereas the number of cases acquired in Asia (n = 172) and Africa (n = 809) decreased 2.8% and 3.7%, respectively. Of 775 U.S. civilians who acquired malaria abroad, only 160 (20.6%) reported that they had followed a chemoprophylactic drug regimen recommended by CDC for the area to which they had traveled. Four patients became infected in the United States; three cases were attributed to congenital transmission and one to laboratory-related mosquitoborne transmission. Four deaths were attributed to malaria, including two caused by P. falciparum, one by P. vivax, and one by a mixed infection with P. falciparum and P. malariae. INTERPRETATION: The 3.6% increase in malaria cases in 2004, compared with 2003, resulted primarily from an increase in the number of cases acquired in the Americas but was offset by a decrease in the number of cases acquired in Africa and Asia. This limited increase might reflect local changes in disease transmission, increased travel to regions in which malaria is endemic, or fluctuations in reporting to state and local health departments. These changes likely reflect expected variation in annual reporting and should not be interpreted as indicating a longer-term trend. In the majority of reported cases, U.S. civilians who acquired infection abroad had not adhered to a chemoprophylaxis regimen that was appropriate for the country in which they acquired malaria. PUBLIC HEALTH ACTIONS: Additional investigations were conducted for the four fatal cases and four infections acquired in the United States. Persons traveling to a malarious area should take one of the recommended chemoprophylaxis regimens appropriate for the region of travel and use personal protection measures to prevent mosquito bites. Any person who has been to a malarious area and who subsequently has a fever or influenza-like symptoms should seek medical care immediately and report their travel history to the clinician; investigation should include a blood-film test for malaria. Malaria infections can be fatal if not diagnosed and treated promptly. Recommendations concerning malaria prevention can be obtained from CDC at http://www.cdc.gov/travel or by calling the Malaria Hotline at telephone 770-488-7788. Recommendations concerning malaria treatment can be obtained at http://www.cdc.gov/malaria/diagnosis_treatment/treatment.htm or by calling the Malaria Hotline.

Longitudinal analysis of cryptosporidium species-specific immunoglobulin G antibody responses in Peruvian children.

Cryptosporidium species are ubiquitous in the environment and are frequently detected in the stools of children who live where sanitation conditions are poor. To better characterize the immune response to these parasites, we monitored immunoglobulin G (IgG) antibody levels in a cohort of children from Lima, Peru. Two new enzyme-linked immunosorbent assays based on the C. parvum (bovine, subtype IIa) Iowa strain 17-kDa and 27-kDa antigens were used to measure IgG antibody levels in longitudinal serum samples. Antibody responses were detected during infections with C. parvum, C. felis, and C. meleagridis and with four different subtypes of C. hominis. We also noted that the magnitude of the antibody response was related to the number of previous infections and that older children generally had higher levels of antibodies to the two C. parvum antigens. Antibody responses were not associated with infections with either Cyclospora sp. or Giardia sp. We believe the antibody assays will be important tools for monitoring the success of future public health interventions.