Tropical_Health RSS : Gourt

Relationship of Climate, Geography, and Geology to the Incidence of Rift Valley Fever in Kenya during the 2006-2007 Outbreak.

Relationship of Climate, Geography, and Geology to the Incidence of Rift Valley Fever in Kenya during the 2006-2007 Outbreak. Am J Trop Med Hyg. 2012 Feb;86(2):373-380 Authors: Hightower A, Kinkade C, Nguku PM, Anyangu A, Mutonga D, Omolo J, Njenga MK, Feikin DR, Schnabel D, Ombok M, Breiman RF Abstract Abstract. We estimated Rift Valley fever (RVF) incidence as a function of geological, geographical, and climatological factors during the 2006-2007 RVF epidemic in Kenya. Location information was obtained for 214 of 340 (63%) confirmed and probable RVF cases that occurred during an outbreak from November 1, 2006 to February 28, 2007. Locations with subtypes of solonetz, calcisols, solonchaks, and planosols soil types were highly associated with RVF occurrence during the outbreak period. Increased rainfall and higher greenness measures before the outbreak were associated with increased risk. RVF was more likely to occur on plains, in densely bushed areas, at lower elevations, and in the Somalia acacia ecological zone. Cases occurred in three spatial temporal clusters that differed by the date of associated rainfall, soil type, and land usage. PMID: 22302875 [PubMed - as supplied by publisher]

The Safety of Yellow Fever Vaccine 17D or 17DD in Children, Pregnant Women, HIV+ Individuals, and Older Persons: Systematic Review.

The Safety of Yellow Fever Vaccine 17D or 17DD in Children, Pregnant Women, HIV+ Individuals, and Older Persons: Systematic Review. Am J Trop Med Hyg. 2012 Feb;86(2):359-72 Authors: Thomas RE, Lorenzetti DL, Spragins W, Jackson D, Williamson T Abstract Abstract. Yellow fever vaccine provides long-lasting immunity. Rare serious adverse events after vaccination include neurologic or viscerotropic syndromes or anaphylaxis. We conducted a systematic review of adverse events associated with yellow fever vaccination in vulnerable populations. Nine electronic bibliographic databases and reference lists of included articles were searched. Electronic databases identified 2,415 abstracts for review, and 32 abstracts were included in this review. We identified nine studies of adverse events in infants and children, eight studies of adverse events in pregnant women, nine studies of adverse events in human immunodeficiency virus-positive patients, five studies of adverse events in persons 60 years and older, and one study of adverse events in individuals taking immunosuppressive medications. Two case studies of maternal-neonate transmission resulted in serious adverse events, and the five passive surveillance databases identified very small numbers of cases of yellow fever vaccine-associated viscerotropic disease, yellow fever vaccine-associated neurotropic disease, and anaphylaxis in persons ≥ 60 years. No other serious adverse events were identified in the other studies of vulnerable groups. PMID: 22302874 [PubMed - in process]

Assessing the risk of international spread of yellow Fever virus: a mathematical analysis of an urban outbreak in asuncion, 2008.

Assessing the risk of international spread of yellow Fever virus: a mathematical analysis of an urban outbreak in asuncion, 2008. Am J Trop Med Hyg. 2012 Feb;86(2):349-58 Authors: Johansson MA, Arana-Vizcarrondo N, Biggerstaff BJ, Gallagher N, Marano N, Staples JE Abstract Abstract. Yellow fever virus (YFV), a mosquito-borne virus endemic to tropical Africa and South America, is capable of causing large urban outbreaks of human disease. With the ease of international travel, urban outbreaks could lead to the rapid spread and subsequent transmission of YFV in distant locations. We designed a stochastic metapopulation model with spatiotemporally explicit transmissibility scenarios to simulate the global spread of YFV from a single urban outbreak by infected airline travelers. In simulations of a 2008 outbreak in Asunción, Paraguay, local outbreaks occurred in 12.8% of simulations and international spread in 2.0%. Using simple probabilistic models, we found that local incidence, travel rates, and basic transmission parameters are sufficient to assess the probability of introduction and autochthonous transmission events. These models could be used to assess the risk of YFV spread during an urban outbreak and identify locations at risk for YFV introduction and subsequent autochthonous transmission. PMID: 22302873 [PubMed - in process]

A Three-Component Biomarker Panel for Prediction of Dengue Hemorrhagic Fever.

A Three-Component Biomarker Panel for Prediction of Dengue Hemorrhagic Fever. Am J Trop Med Hyg. 2012 Feb;86(2):341-348 Authors: Brasier AR, Ju H, Garcia J, Spratt HM, Victor SS, Forshey BM, Halsey ES, Comach G, Sierra G, Blair PJ, Rocha C, Morrison AC, Scott TW, Bazan I, Kochel TJ, The Venezuelan Dengue Fever Working Group Abstract Abstract. Dengue virus infections are a major cause of morbidity in tropical countries. Early detection of dengue hemorrhagic fever (DHF) may help identify individuals that would benefit from intensive therapy. Predictive modeling was performed using 11 laboratory values of 51 individuals (38 DF and 13 DHF) obtained on initial presentation using logistic regression. We produced a robust model with an area under the curve of 0.9615 that retained IL-10 levels, platelets, and lymphocytes as the major predictive features. A classification and regression tree was developed on these features that were 86% accurate on cross-validation. The IL-10 levels and platelet counts were also identified as the most informative features associated with DHF using a Random Forest classifier. In the presence of polymerase chain reaction-proven acute dengue infections, we suggest a complete blood count and rapid measurement of IL-10 can assist in the triage of potential DHF cases for close follow-up or clinical intervention improving clinical outcome. PMID: 22302872 [PubMed - as supplied by publisher]

Molecular detection and typing of dengue viruses from archived tissues of fatal cases by rt-PCR and sequencing: diagnostic and epidemiologic implications.

Molecular detection and typing of dengue viruses from archived tissues of fatal cases by rt-PCR and sequencing: diagnostic and epidemiologic implications. Am J Trop Med Hyg. 2012 Feb;86(2):335-40 Authors: Bhatnagar J, Blau DM, Shieh WJ, Paddock CD, Drew C, Liu L, Jones T, Patel M, Zaki SR Abstract Abstract. Diagnosis of dengue virus (DENV) infection in fatal cases is challenging because of the frequent unavailability of blood or fresh tissues. For formalin-fixed, paraffin-embedded (FFPE) tissues immunohistochemistry (IHC) can be used; however, it may not be as sensitive and serotyping is not possible. The application of reverse transcription-polymerase chain reaction (RT-PCR) for the detection of DENV in FFPE tissues has been very limited. We evaluated FFPE autopsy tissues of 122 patients with suspected DENV infection by flavivirus and DENV RT-PCR, sequencing, and DENV IHC. The DENV was detected in 61 (50%) cases by RT-PCR or IHC. The RT-PCR and sequencing detected DENV in 60 (49%) cases (DENV-1 in 16, DENV-2 in 27, DENV-3 in 8, and DENV-4 in 6 cases). No serotype could be identified in three cases. The IHC detected DENV antigens in 50 (40%) cases. The RT-PCR using FFPE tissue improves detection of DENV in fatal cases and provides sequence information useful for typing and epidemiologic studies. PMID: 22302871 [PubMed - in process]

Factors associated with dengue mortality in latin america and the Caribbean, 1995-2009: an ecological study.

Factors associated with dengue mortality in latin america and the Caribbean, 1995-2009: an ecological study. Am J Trop Med Hyg. 2012 Feb;86(2):328-34 Authors: Díaz-Quijano FA, Waldman EA Abstract Abstract. In this study, we aimed to estimate the effect that environmental, demographic, and socioeconomic factors have on dengue mortality in Latin America and the Caribbean. To that end, we conducted an observational ecological study, analyzing data collected between 1995 and 2009. Dengue mortality rates were highest in the Caribbean (Spanish-speaking and non-Spanish-speaking). Multivariate analysis through Poisson regression revealed that the following factors were independently associated with dengue mortality: time since identification of endemicity (adjusted rate ratio [aRR] = 3.2 [for each 10 years]); annual rainfall (aRR = 1.5 [for each 10(3) L/m(2)]); population density (aRR = 2.1 and 3.2 for 20-120 inhabitants/km(2) and > 120 inhabitants/km(2), respectively); Human Development Index > 0.83 (aRR = 0.4); and circulation of the dengue 2 serotype (aRR = 1.7). These results highlight the important role that environmental, demographic, socioeconomic, and biological factors have played in increasing the severity of dengue in recent decades. PMID: 22302870 [PubMed - in process]

Human Risk of Infection with Borrelia burgdorferi, the Lyme Disease Agent, in Eastern United States.

Human Risk of Infection with Borrelia burgdorferi, the Lyme Disease Agent, in Eastern United States. Am J Trop Med Hyg. 2012 Feb;86(2):320-327 Authors: Diuk-Wasser MA, Hoen AG, Cislo P, Brinkerhoff R, Hamer SA, Rowland M, Cortinas R, Vourc'h G, Melton F, Hickling GJ, Tsao JI, Bunikis J, Barbour AG, Kitron U, Piesman J, Fish D Abstract Abstract. The geographic pattern of human risk for infection with Borrelia burgdorferi sensu stricto, the tick-borne pathogen that causes Lyme disease, was mapped for the eastern United States. The map is based on standardized field sampling in 304 sites of the density of Ixodes scapularis host-seeking nymphs infected with B. burgdorferi, which is closely associated with human infection risk. Risk factors for the presence and density of infected nymphs were used to model a continuous 8 km×8 km resolution predictive surface of human risk, including confidence intervals for each pixel. Discontinuous Lyme disease risk foci were identified in the Northeast and upper Midwest, with a transitional zone including sites with uninfected I. scapularis populations. Given frequent under- and over-diagnoses of Lyme disease, this map could act as a tool to guide surveillance, control, and prevention efforts and act as a baseline for studies tracking the spread of infection. PMID: 22302869 [PubMed - as supplied by publisher]

Leptospirosis in american samoa 2010: epidemiology, environmental drivers, and the management of emergence.

Leptospirosis in american samoa 2010: epidemiology, environmental drivers, and the management of emergence. Am J Trop Med Hyg. 2012 Feb;86(2):309-19 Authors: Lau CL, Dobson AJ, Smythe LD, Fearnley EJ, Skelly C, Clements AC, Craig SB, Fuimaono SD, Weinstein P Abstract Abstract. Leptospirosis has recently been reported as an emerging disease worldwide, and a seroprevalence study was undertaken in American Samoa to better understand the drivers of transmission. Antibodies indicative of previous exposure to leptospirosis were found in 15.5% of 807 participants, predominantly against three serovars that were not previously known to occur in American Samoa. Questionnaires and geographic information systems data were used to assess behavioral factors and environmental determinants of disease transmission, and logistic regression was used to identify factors associated with infection. Many statistically significant factors were consistent with previous studies, but we also showed a significant association with living at lower altitudes (odds ratio [OR] = 1.53, 95% confidence interval [CI]: 1.03-2.28), and having higher numbers of piggeries around the home (OR = 2.63, 95% CI: 1.52-4.40). Our findings support a multifaceted approach to combating the emergence of leptospirosis, including modification of individual behavior, but importantly also managing the evolving environmental drivers of risk. PMID: 22302868 [PubMed - in process]

Comparative analysis of severe pediatric and adult leptospirosis in sao paulo, Brazil.

Comparative analysis of severe pediatric and adult leptospirosis in sao paulo, Brazil. Am J Trop Med Hyg. 2012 Feb;86(2):306-8 Authors: Spichler A, Athanazio DA, Vilaça P, Seguro A, Vinetz J, Leake JA Abstract Abstract. Although leptospirosis may be fatal in childhood, the experience of many clinicians working in disease-endemic areas is that classic Weil's disease and death are less common among pediatric patients. The aim of the study was to ascertain disease spectrum and outcome differences in severe pediatric and adult leptospirosis in a large at-risk population. Epidemiologic, clinical, and laboratory data were obtained on hospitalized cases from São Paulo during 2004-2006. A total of 42 case-patients < 18 years of age and 328 case-patients ≥ 18 years of age were tested during the study. Compared with children, adults had higher rates of jaundice (P = 0.01), elevated serum bilirubin levels (P < 0.01), oliguria (P = 0.02), and elevated creatinine levels (P = 0.01) but not for thrombocytopenia or pulmonary involvement. The overall case-fatality rate was 27% (adult) versus 5% (pediatric) (P < 0.01). Severe pediatric leptospirosis may be less likely to show all classic features of Weil's disease and may be less fatal than in adults. PMID: 22302867 [PubMed - in process]

Factors Associated with Resistance to Schistosoma mansoni Infection in an Endemic Area of Bahia, Brazil.

Factors Associated with Resistance to Schistosoma mansoni Infection in an Endemic Area of Bahia, Brazil. Am J Trop Med Hyg. 2012 Feb;86(2):296-305 Authors: Oliveira RR, Figueiredo JP, Cardoso LS, Jabar RL, Souza RP, Wells MT, Carvalho EM, Fitzgerald DW, Barnes KC, Araújo MI, Glesby MJ Abstract Abstract. Detailed knowledge of factors associated with resistance to Schistosoma mansoni infection in endemic areas might facilitate more effective schistosomiasis control. We conducted a cross-sectional study of persons resistant to schistosomiasis and found no association between socioeconomic status and resistance to infection. Mononuclear cells of resistant subjects produced higher levels of interleukin-5 (IL-5), IL-13 and interferon-γ upon stimulation with soluble egg antigen (SEA) compared with infected persons. When stimulated with Sm21.6 or Sm22.6, levels of IL-10 were higher in cell culture of resistant persons. Levels of IgE against soluble adult worm antigen (SWAP) and against interleukin-4-inducing principle from S. mansoni eggs (IPSE) and levels of IgG4 against SWAP, SEA, and Sm22.6 were lower in the resistant group compared with the susceptible group. Our data suggest that socioeconomic status could not fully explain resistance to S. mansoni infection observed in the studied area. However, a mixture of Th1 and Th2 immune responses and low levels of specific IgG4 against parasite antigens could be mediating resistance to infection. PMID: 22302866 [PubMed - as supplied by publisher]

Sexually Transmitted Infections in Newly Arrived Refugees: Is Routine Screening for Neisseria gonorrheae and Chlamydia trachomatis Infection Indicated?

Sexually Transmitted Infections in Newly Arrived Refugees: Is Routine Screening for Neisseria gonorrheae and Chlamydia trachomatis Infection Indicated? Am J Trop Med Hyg. 2012 Feb;86(2):292-5 Authors: Stauffer WM, Painter J, Mamo B, Kaiser R, Weinberg M, Berman S Abstract Abstract. More than 340 million cases of bacterial and protozoal sexually transmitted infections (STIs) occur annually. Approximately 70,000 refugees arrive in the United States on a yearly basis. Refugees are a particularly disenfranchised and vulnerable population. The prevalence of Chlamydia and gonorrhea in refugee populations has not been described, and the utility of routine screening is unknown. We performed a descriptive evaluation of 25,779 refugees who completed a screening medical examination in Minnesota during 2003-2010. A total of 18,516 (72%) refugees were tested for at least one STI: 183 (1.1%) of 17,235 were seropositive for syphilis, 15 (0.6%) of 2,512 were positive for Chlamydia, 5 (0.2%) of 2,403 were positive for gonorrhea, 136 (2.0%) of 6,765 were positive for human immunodeficiency virus, and 6 (0.1%) of 5,873 were positive for multiple STIs. Overall prevalence of Chlamydia (0.6%) and gonorrhea (0.2%) infection was low, which indicated that routine screening may not be indicated. However, further research on this subject is encouraged. PMID: 22302865 [PubMed - in process]

Prediction of child health by household density and asset-based indices in impoverished indigenous villages in rural panama.

Prediction of child health by household density and asset-based indices in impoverished indigenous villages in rural panama. Am J Trop Med Hyg. 2012 Feb;86(2):280-91 Authors: Halpenny CM, Koski KG, Valdés VE, Scott ME Abstract Abstract. Chronic infection over a 16-month period and stunting of preschool children were compared between more spatially dense versus dispersed households in rural Panamá. Chronic protozoan infection was associated with higher household density, lower household wealth index, poor household water quality, yard defecation, and the practice of not washing hands with soap before eating. Models for chronic diarrhea confirmed the importance of household wealth, water quality, sanitation, and hygiene practices. Furthermore, chronic protozoan infection was an important predictor for low height-for-age, along with low household wealth index scores, but not household density. Thus, despite better access to health related infrastructure in the more densely populated households, chronic protozoan infection was more common, and was associated with higher rates of child stunting, compared with more dispersed households. PMID: 22302864 [PubMed - in process]

Non-invasive assessment of fibrosis using color Doppler ultrasound in patients with hepatitis C virus in the Amazon rainforest, Brazil.

Non-invasive assessment of fibrosis using color Doppler ultrasound in patients with hepatitis C virus in the Amazon rainforest, Brazil. Am J Trop Med Hyg. 2012 Feb;86(2):273-9 Authors: Leão J, Brock M, Castilho M, Scariot A, Scariot A, Braga W Abstract Abstract. The purpose of this study was to correlate morphologic and hemodynamic Doppler ultrasound findings as indicators of the degree of inflammation and fibrosis and to diagnose chronic vital hepatitis complications and progression. A prospective, descriptive study of a case series was conducted that analyzed Doppler ultrasound images of the liver and portal system and used the portal vein congestion index, hepatic and splenic artery impedance indices, and the liver vascular index. Of 50 patients positive for antibodies against hepatitis C virus, morphologic changes highlighted increased hepatic parenchyma echogenicity in 24%, and increased gall blander echogenicity and wall thickness in 4%. The most common hemodynamic changes observed were reduced flow velocity in the portal vein trunk in 26%, congestion index changes in 12%, liver vascular index changes in 16%, and splenic and hepatic artery impedance index changes in 14%. These indices were shown to be associated with alanine aminotransferase levels, which suggested that they are important liver damage indicators in the early phase of infection with hepatitis C virus. PMID: 22302863 [PubMed - in process]

Pseudotumoral form of neuroschistosomiasis: report of three cases in ganzi, china.

Pseudotumoral form of neuroschistosomiasis: report of three cases in ganzi, china. Am J Trop Med Hyg. 2012 Feb;86(2):268-72 Authors: Wan H, Masataka H, Zhang LP, Zheng DF Abstract Abstract. The authors report three rare cases of neuroschistosomiasis lacking extracranial involvement. No parasitic eggs were detected in the stool with the Kato-Katz thick smear methods. Computed tomography of the brains showed hypodense signals, and magnetic resonance imaging showed isointense signals on T1-weighted images, hyperintense signals on T2-weighted images, and intensely enhancing nodules in the brain after intravenous administration of gadolinium. High-grade gliomas were suspected, and operations or radiosurgery was performed. Cerebral schistosomiasis was confirmed in all cases by biopsy of the brain lesions, revealing granulomas containing embedded Schistosoma japonicum eggs. All cases were definitively diagnosed as brain schistosomiasis japonica. Praziquantel and corticosteroids were administered, and the prognoses were good for all case patients. Although the aforementioned pattern of imaging examinations is not present in all cases of neuroschistosomiasis, a diagnosis of neuroschistosomiasis should be considered when this pattern of imaging is observed; cerebrospinal fluid serological exams are also recommended. PMID: 22302862 [PubMed - in process]

Recurrent disseminated intravascular coagulation caused by intermittent dosing of rifampin.

Recurrent disseminated intravascular coagulation caused by intermittent dosing of rifampin. Am J Trop Med Hyg. 2012 Feb;86(2):264-7 Authors: Havey TC, Cserti-Gazdewich C, Sholzberg M, Keystone JS, Gold WL Abstract Abstract. Daily rifampin therapy is associated with minimal adverse effects, but administration on an intermittent or interrupted basis has been associated with severe immunoallergic reactions such as hemolytic anemia, acute renal failure, and disseminated intravascular coagulation. We describe a patient with Mycobacterium leprae infection who experienced recurrent episodes of disseminated intravascular coagulation after intermittent exposures to rifampin, and review eight previously reported cases of rifampin-associated disseminated intravascular coagulation. In six (75%) cases, previous exposure to rifampin was reported and seven (87.5%) patients were receiving the medication on an intermittent or interrupted basis. Clinical features of rifampin-associated disseminated intravascular coagulation included fever, hypotension, abdominal pain, and vomiting within hours of ingestion. Average time to reaction was 3-6 doses if rifampin was being administered on a monthly schedule. Three (37.5%) of eight reported cases were fatal. A complete history of previous exposure to rifampin is recommended before intermittent therapy with this medication. PMID: 22302861 [PubMed - in process]

An Unusual Cutaneous Tumor: African Histoplasmosis following Mudbaths: Case Report and Review.

An Unusual Cutaneous Tumor: African Histoplasmosis following Mudbaths: Case Report and Review. Am J Trop Med Hyg. 2012 Feb;86(2):261-3 Authors: Tsiodras S, Drogari-Apiranthitou M, Pilichos K, Leventakos K, Kelesidis T, Buitrago MJ, Petrikkos G, Panayiotides I Abstract Abstract. African histoplasmosis, caused by Histoplasma capsulatum var. duboisii, is endemic in Africa. The disease usually involves the skin, subcutaneous tissue, and bones. A case of African histoplasmosis presenting as a cutaneous tumor and non-healing wound in a 66-year-old immunocompetent male residing in Africa, the first ever reported following mudbaths and acupuncture, is hereby reported. Diagnosis was confirmed by means of polymerase chain reaction performed on tissue material. The patient was started on long-term itraconazole therapy and he responded well. African histoplasmosis should be included in the differential diagnosis of non-healing wounds or tumor-like lesions, especially in the context of mudbaths in an endemic area. PMID: 22302860 [PubMed - in process]

Unusual presentations of pediatric neurobrucellosis.

Unusual presentations of pediatric neurobrucellosis. Am J Trop Med Hyg. 2012 Feb;86(2):258-60 Authors: Budnik I, Fuchs I, Shelef I, Krymko H, Greenberg D Abstract Abstract. Neurobrucellosis is an uncommon complication of pediatric brucellosis. Acute meningitis and encephalitis are the most common clinical manifestations, however symptoms may be protean and diagnosis requires a high index of suspicion in patients from endemic areas. Diagnosis is often based on neurological symptoms, serology, and suggestive brain imaging because cerebrospinal fluid culture yields are low. Two cases of pediatric neurobrucellosis with unusual clinical and radiologic findings are presented. PMID: 22302859 [PubMed - in process]

Saw-scaled viper bites in sri lanka: is it a different subspecies? Clinical evidence from an authenticated case series.

Saw-scaled viper bites in sri lanka: is it a different subspecies? Clinical evidence from an authenticated case series. Am J Trop Med Hyg. 2012 Feb;86(2):254-7 Authors: Gnanathasan A, Rodrigo C, Peranantharajah T, Coonghe A Abstract Abstract. The saw-scaled viper (SSV) (Echis carinatus) is considered to be a highly venomous snake in Sri Lanka despite any published clinical justification. Being a rarity, the clinical profile of SSV bites is not well established in Sri Lanka. We report a series of 48 (n-48) SSV bites from the Northern Province of Sri Lanka. The majority (65%) of victims had evidence of local envenoming at the site of the bite; however, 29% showed spontaneous bleeding and 71% had coagulopathy. There were no deaths in the series. The envenoming was mild in contrast to the mortality and significant morbidity associated with SSV bites in West Africa and some parts of India. These observations need to be further explored with laboratory studies to identify the venom components, study of morphological characteristics, and genetic profiling of the Sri Lankan SSV to see if it is different from the subspecies found elsewhere. PMID: 22302858 [PubMed - in process]

Infectious Etiologies of Acute Febrile Illness among Patients Seeking Health Care in South-Central Cambodia.

Infectious Etiologies of Acute Febrile Illness among Patients Seeking Health Care in South-Central Cambodia. Am J Trop Med Hyg. 2012 Feb;86(2):246-53 Authors: Kasper MR, Blair PJ, Touch S, Sokhal B, Yasuda CY, Williams M, Richards AL, Burgess TH, Wierzba TF, Putnam SD Abstract Abstract. The agents of human febrile illness can vary by region and country suggesting that diagnosis, treatment, and control programs need to be based on a methodical evaluation of area-specific etiologies. From December 2006 to December 2009, 9,997 individuals presenting with acute febrile illness at nine health care clinics in south-central Cambodia were enrolled in a study to elucidate the etiologies. Upon enrollment, respiratory specimens, whole blood, and serum were collected. Testing was performed for viral, bacterial, and parasitic pathogens. Etiologies were identified in 38.0% of patients. Influenza was the most frequent pathogen, followed by dengue, malaria, and bacterial pathogens isolated from blood culture. In addition, 3.5% of enrolled patients were infected with more than one pathogen. Our data provide the first systematic assessment of the etiologies of acute febrile illness in south-central Cambodia. Data from syndromic-based surveillance studies can help guide public health responses in developing nations. PMID: 22302857 [PubMed - in process]

Predictors of Acute Bacterial Meningitis in Children from a Malaria-Endemic Area of Papua New Guinea.

Predictors of Acute Bacterial Meningitis in Children from a Malaria-Endemic Area of Papua New Guinea. Am J Trop Med Hyg. 2012 Feb;86(2):240-245 Authors: Laman M, Manning L, Greenhill AR, Mare T, Michael A, Shem S, Vince J, Lagani W, Hwaiwhanje I, Siba PM, Mueller I, Davis TM Abstract Abstract. Predictors of acute bacterial meningitis (ABM) were assessed in 554 children in Papua New Guinea 0.2-10 years of age who were hospitalized with culture-proven meningitis, probable meningitis, or non-meningitic illness investigated by lumbar puncture. Forty-seven (8.5%) had proven meningitis and 36 (6.5%) had probable meningitis. Neck stiffness, Kernig's and Brudzinski's signs and, in children < 18 months of age, a bulging fontanel had positive likelihood ratios (LRs) ≥ 4.3 for proven/probable ABM. Multiple seizures and deep coma were less predictive (LR = 1.5-2.1). Single seizures and malaria parasitemia had low LRs (≤ 0.5). In logistic regression including clinical variables, Kernig's sign and deep coma were positively associated with ABM, and a single seizure was negatively associated (P ≤ 0.01). In models including microscopy, neck stiffness and deep coma were positively associated with ABM and parasitemia was negatively associated with ABM (P ≤ 0.04). In young children, a bulging fontanel added to the model (P < 0.001). Simple clinical features predict ABM in children in Papua New Guinea but malaria microscopy augments diagnostic precision. PMID: 22302856 [PubMed - as supplied by publisher]

Verbal autopsy for neurological diseases.

Verbal autopsy for neurological diseases. Am J Trop Med Hyg. 2012 Feb;86(2):237-9 Authors: Mateen FJ, Kalter HD Abstract Abstract. Verbal autopsy is an interview-based technique to determine the cause distribution of death in a population. The use of verbal autopsy for understanding neurological diseases is crucial to burden of disease analyses in many countries, particularly in locations where civil registration systems are non-functioning or absent. We review the purposes, strengths, and weaknesses in the use of verbal autopsy for neurological diseases. PMID: 22302855 [PubMed - in process]

Detection and Transmission of Dientamoeba fragilis from Environmental and Household Samples.

Detection and Transmission of Dientamoeba fragilis from Environmental and Household Samples. Am J Trop Med Hyg. 2012 Feb;86(2):233-6 Authors: Stark D, Roberts T, Marriott D, Harkness J, Ellis JT Abstract Abstract. Dientamoeba fragilis is a commonly occurring pathogenic protozoan often detected at higher rates in stool samples than Giardia intestinalis. However, little is known about its life cycle and mode of transmission. A total of 210 environmental and household samples were examined for the presence of D. fragilis by culture and polymerase chain reaction. Of 100 environmental samples, D. fragilis was detected only in untreated sewage. In the household samples D. fragilis was detected in 30% of household contacts tested and was not detected in any domestic pets. This study provides evidence that environmental transmission of D. fragilis is unlikely and that pets played no role in transmission of the disease in this study. Direct transmission from infected persons is the most likely mode of transmission for D. fragilis. The study also highlights the need for household contacts to be screened, given the propensity of close contacts to become infected with the organism. PMID: 22302854 [PubMed - in process]

Mannose-Binding Lectin and Toll-Like Receptor Polymorphisms and Chagas Disease in Chile.

Mannose-Binding Lectin and Toll-Like Receptor Polymorphisms and Chagas Disease in Chile. Am J Trop Med Hyg. 2012 Feb;86(2):229-232 Authors: Weitzel T, Zulantay I, Danquah I, Hamann L, Schumann RR, Apt W, Mockenhaupt FP Abstract Abstract. Mannose-binding lectin (MBL) and Toll-like receptor (TLR) polymorphisms may influence susceptibility and manifestation of Trypanosoma cruzi infection. In northern Chile, we examined 61 asymptomatic patients with chronic Chagas disease (CD), 64 patients with chronic Chagas cardiomyopathy (CCC), and 45 healthy individuals. Low-producer MBL2*B genotypes were more common in CD patients (48%) than healthy individuals (31%; adjusted odds ratio = 2.3, 95% confidence interval = 1.01-5.4, P = 0.047) but did not differ with manifestation. In contrast, the heterozygous Toll-like receptor 4 (TLR4)-deficiency genotype D299G/T399I occurred more frequently in asymptomatic (14.8%) than CCC patients (3.1%; P = 0.02). TLR1-I602S, TLR2-R753Q, TLR6-S249P, and MAL/TIRAP-S180L did not associate with CD or CCC. These findings support the complement system to be involved in defense against Trypanosoma cruzi infection and indicate that curbed TLR4 activation might be beneficial in preventing CCC. PMID: 22302853 [PubMed - as supplied by publisher]

Evaluation of the Solar Water Disinfection Process (SODIS) Against Cryptosporidium parvum Using a 25-L Static Solar Reactor Fitted with a Compound Parabolic Collector (CPC).

Evaluation of the Solar Water Disinfection Process (SODIS) Against Cryptosporidium parvum Using a 25-L Static Solar Reactor Fitted with a Compound Parabolic Collector (CPC). Am J Trop Med Hyg. 2012 Feb;86(2):223-8 Authors: Fontán-Sainz M, Gómez-Couso H, Fernández-Ibáñez P, Ares-Mazás E Abstract Abstract. Water samples of 0, 5, and 30 nephelometric turbidity units (NTU) spiked with Cryptosporidium parvum oocysts were exposed to natural sunlight using a 25-L static solar reactor fitted with a compound parabolic collector (CPC). The global oocyst viability was calculated by the evaluation of the inclusion/exclusion of the fluorogenic vital dye propidium iodide and the spontaneous excystation. After an exposure time of 8 hours, the global oocyst viabilities were 21.8 ± 3.1%, 31.3 ± 12.9%, and 45.0 ± 10.0% for turbidity levels of 0, 5, and 30 NTU, respectively, and these values were significantly lower (P < 0.05) that the initial global viability of the isolate (92.1 ± 0.9%). The 25-L static solar reactor that was evaluated can be an alternative system to the conventional solar water disinfection process for improving the microbiological quality of drinking water on a household level, and moreover, it enables treatment of larger volumes of water (> 10 times). PMID: 22302852 [PubMed - in process]

Systemic Antibody Responses to the Immunodominant p23 Antigen and p23 Polymorphisms in Children with Cryptosporidiosis in Bangladesh.

Systemic Antibody Responses to the Immunodominant p23 Antigen and p23 Polymorphisms in Children with Cryptosporidiosis in Bangladesh. Am J Trop Med Hyg. 2012 Feb;86(2):214-222 Authors: Borad AJ, Allison GM, Wang D, Ahmed S, Karim MM, Kane AV, Moy J, Hibberd PL, Rao Ajjampur SS, Kang G, Calderwood SB, Ryan ET, Naumova E, Khan WA, Ward HD Abstract Abstract. Cryptosporidium is a major cause of diarrhea in children in developing countries. However, there is no vaccine available and little is known about immune responses to protective antigens. We investigated antibody responses to p23, a putative vaccine candidate, in children in Bangladesh with cryptosporidiosis and diarrhea (cases) and uninfected children with diarrhea (controls), and p23 gene polymorphisms in infecting species. Serum IgM, IgG, and IgA responses to p23 were significantly greater in cases than controls after three weeks of follow-up. Cases with acute diarrhea had significantly greater serum IgA and IgM responses than those with persistent diarrhea, which suggested an association with protection from prolonged disease. The p23 sequences were relatively conserved among infecting species and subtype families. Although most children were infected with Cryptosporidium hominis, there was a cross-reactive antibody response to C. parvum antigen. These results support further development of p23 as a vaccine candidate. PMID: 22302851 [PubMed - as supplied by publisher]

Different Patterns of pfcrt and pfmdr1 Polymorphisms in P. falciparum Isolates from Nigeria and Brazil: The Potential Role of Antimalarial Drug Selection Pressure.

Different Patterns of pfcrt and pfmdr1 Polymorphisms in P. falciparum Isolates from Nigeria and Brazil: The Potential Role of Antimalarial Drug Selection Pressure. Am J Trop Med Hyg. 2012 Feb;86(2):211-3 Authors: Gbotosho GO, Folarin OA, Bustamante C, Pereira da Silva LH, Mesquita E, Sowunmi A, Zalis MG, Oduola AM, Happi CT Abstract Abstract. The effect of antimalarial drug selection on pfcrt and pfmdr1 polymorphisms in Plasmodium falciparum isolates from two distinct geographical locations was determined in 70 and 18 P. falciparum isolates from Nigeria and Brazil, respectively, using nested polymerase chain reaction and direct DNA sequencing approaches. All isolates from Brazil and 72% from Nigeria harbored the mutant SVMNT and CVIET pfcrt haplotype, respectively. The pfcrt CVMNT haplotype was also observed in (7%) of the Nigerian samples. One hundred percent (100%) and 54% of the parasites from Brazil and Nigeria, respectively, harbored wild-type pfmdr1Asn86. We provide first evidence of emergence of the CVMNT haplotype in West Africa. The high prevalence of pfcrt CVIET and SVMNT haplotypes in Nigeria and Brazil, respectively, is indicative of different selective pressure by chloroquine and amodiaquine. Continuous monitoring of pfcrt SVMNT haplotype is required in endemic areas of Africa, where artesunate-amodiaquine combination is used for treatment of acute uncomplicated malaria. PMID: 22302850 [PubMed - in process]

Compliance, Safety, and Effectiveness of Fixed-Dose Artesunate-Amodiaquine for Presumptive Treatment of Non-Severe Malaria in the Context of Home Management of Malaria in Madagascar.

Compliance, Safety, and Effectiveness of Fixed-Dose Artesunate-Amodiaquine for Presumptive Treatment of Non-Severe Malaria in the Context of Home Management of Malaria in Madagascar. Am J Trop Med Hyg. 2012 Feb;86(2):203-210 Authors: Ratsimbasoa A, Ravony H, Vonimpaisomihanta JA, Raherinjafy R, Jahevitra M, Rapelanoro R, Rakotomanga JD, Malvy D, Millet P, Ménard D Abstract Abstract. Home management of malaria is recommended for prompt, effective antimalarial treatment in children less than five years of age. Compliance, safety, and effectiveness of the new fixed-dose artesunate-amodiaquine regimen used to treat suspected malaria were assessed in febrile children enrolled in a 24-month cohort study in two settings in Madagascar. Children with fever were asked to visit community health workers. Presumptive antimalarial treatment was given and further visits were scheduled for follow-up. The primary endpoint was the risk of clinical/parasitologic treatment failure. Secondary outcomes included fever/parasite clearance, change in hemoglobin levels, and frequency of adverse events. The global clinical cure rate was 98.4% by day 28 and 97.9% by day 42. Reported compliance was 83.4%. No severe adverse effects were observed. This study provides comprehensive data concerning the clinical cure rate obtained with artesunate-amodiaquine and evidence supporting the scaling up of home management of malaria. PMID: 22302849 [PubMed - as supplied by publisher]

Performance of Two Malaria Rapid Diagnostic Tests in Febrile Adult Patients with and without Human Immunodeficiency Virus-1 Infection in Blantyre, Malawi.

Performance of Two Malaria Rapid Diagnostic Tests in Febrile Adult Patients with and without Human Immunodeficiency Virus-1 Infection in Blantyre, Malawi. Am J Trop Med Hyg. 2012 Feb;86(2):199-202 Authors: Chinkhumba J, Nyanda M, Skarbinski J, Mathanga DP Abstract Abstract. The performance of two histidine-rich protein type-2-based malaria rapid diagnostic tests (mRDTs) was examined in a rural area with a high prevalence of malaria and human immunodeficiency virus type-1 (HIV-1) infection in 113 and 445 febrile patients ≥ 15 years of age with and without HIV-1 infection, respectively. Patients were tested for HIV-1 infection by using a standard assay and for Plasmodium falciparum by using two mRDTs and microscopy. When microscopy was used as the gold standard, both mRDTs performed similarly in patients with and without HIV-1 infection: Bioline SD Malaria Antigen P.f, sensitivity 94.4% (95% confidence interval [CI]: 81.3-99.3%) versus 97.1% (95% CI:92.8-99.2%) and specificity 50.6% (95% CI: 39.0-62.2%) versus 47.2% (95% CI: 41.4-53.1%); and ICT diagnostics Malaria Pf, sensitivity 94.4% (95% CI: 81.3-99.3%) versus 97.1% (95% CI: 92.8-99.2%) and specificity 50.6% (95% CI:39.0-62.2%) versus 50.3% (95% CI: 44.4-56.1%). Infection with HIV-1 does not appear to affect the performance of these histidine-rich protein type-2 (HRP-2)-based mRDTs. PMID: 22302848 [PubMed - in process]

False-Negative Rapid Diagnostic Tests for Malaria and Deletion of the Histidine-Rich Repeat Region of the hrp2 Gene{dagger}.

False-Negative Rapid Diagnostic Tests for Malaria and Deletion of the Histidine-Rich Repeat Region of the hrp2 Gene{dagger}. Am J Trop Med Hyg. 2012 Feb;86(2):194-8 Authors: Koita OA, Doumbo OK, Ouattara A, Tall LK, Konaré A, Diakité M, Diallo M, Sagara I, Masinde GL, Doumbo SN, Dolo A, Tounkara A, Traoré I, Krogstad DJ Abstract Abstract. We identified 480 persons with positive thick smears for asexual Plasmodium falciparum parasites, of whom 454 had positive rapid diagnostic tests (RDTs) for the histidine-rich protein 2 (HRP2) product of the hrp2 gene and 26 had negative tests. Polymerase chain reaction (PCR) amplification for the histidine-rich repeat region of that gene was negative in one-half (10/22) of false-negative specimens available, consistent with spontaneous deletion. False-negative RDTs were found only in persons with asymptomatic infections, and multiplicities of infection (MOIs) were lower in persons with false-negative RDTs (both P < 0.001). These results show that parasites that fail to produce HRP2 can cause patent bloodstream infections and false-negative RDT results. The importance of these observations is likely to increase as malaria control improves, because lower MOIs are associated with false-negative RDTs and false-negative RDTs are more frequent in persons with asymptomatic infections. These findings suggest that the use of HRP2-based RDTs should be reconsidered. PMID: 22302847 [PubMed - in process]

How do we best diagnose malaria in Africa?

How do we best diagnose malaria in Africa? Am J Trop Med Hyg. 2012 Feb;86(2):192-3 Authors: Rosenthal PJ PMID: 22302846 [PubMed - in process]

Recommendations for Publication of Viral Genetic Data and Sample Access for Novel Viruses and Strains.

Recommendations for Publication of Viral Genetic Data and Sample Access for Novel Viruses and Strains. Am J Trop Med Hyg. 2012 Feb;86(2):189-191 Authors: Arrigo NC, Briese T, Calisher CH, Drebot MA, Hjelle B, Leduc JW, Powers AM, Repik PM, Roehrig JT, Schmaljohn CS, Tesh RB, Weaver SC PMID: 22302845 [PubMed - as supplied by publisher]