bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluation of Bednets After 38 Months of Household Use in Northwest Ghana
Authors: Smith Stephen C. , Joshi Uday B. , Grabowsky Mark , Selanikio Joel , Nobiya Theresa , Aapore Thomas
Published: September 2018

A total of 255 bednets were collected 38 months after distribution in Lawra District of northwest Ghana to examine their physical condition and residual insecticide levels. Physical condition varied from nearly pristine to highly damaged. In 50 selected nets, 2023 holes ≥ 0.5 cm and 31 holes ≥ 10 cm were counted. The incidence of holes increases toward the bottom edge of the net. Seam failures were found in 50% of the nets. Repairs, mostly sewn, were evident in 64% of the nets. Using a combination of bromine x-ray fluorescence (XRF) spectrometry, high-pressure liquid chromatography, and cone bioassays, it was determined that 14.9% of the nets had retained full insecticidal strength. These results highlight the value of real-world data on bednet longevity to guide decisions regarding mosquito control strategies, bednet purchasing, frequency of bednet replacement, and product development.
Metabolic Acidosis and Other Determinants of Hemoglobin-Oxygen Dissociation in Severe Childhood Plasmodium falciparum Malaria
Authors: Sasi Philip , Burns Shamus P. , Waruiru Catherine , English Michael , Hobson Claire L. , King Christopher G. , Mosobo Moses , Beech John S. , Iles Richard A. , Boucher Barbara J. , Cohen Robert D.
Published: September 2018

Metabolic acidosis is a common complication of severe malaria caused by Plasmodium falciparum. The factors contributing to the acidosis were assessed in 62 children with severe falciparum malaria (cases) and in 29 control children who had recently recovered from mild or moderate malaria. The acidosis was largely caused by the accumulation of both lactic and 3-hydroxybutyric acids. The determinants of oxygen release to the tissues were also examined; although there was no difference between cases and controls in respect of 2,3-bisphosphoglycerate and mean corpuscular hemoglobin concentration, there was a marked increase in P50 in the cases, caused by pyrexia, low pH, and base deficit. There was substantial relative or actual hypoglycemia in many cases. The relationship of these observations to therapeutic strategy is discussed.
Adaptation of a Multi-drug Resistant Strain of Plasmodium falciparum from Peru to Aotus lemurinus griseimembra, A. nancymaae, and A. vociferans Monkeys
Authors: Collins William E. , Sullivan Joann S. , Hall Patrice , Ruebush Trenton K. , Williams Allison , Grady Katharine K. , Bounngaseng Amy , Nace Douglas , Williams Tyrone , Huber Curtis , Galland G. Gale , Barnwell John W. , Sullivan James J.
Published: September 2018

A strain of Plasmodium falciparum from Peru was adapted to splenectomized Aotus nancymaae and Aotus vociferans monkeys. The Peru 134/CDC strain of P. falciparum was shown to be resistant to treatment with chloroquine in monkeys and partially resistant to mefloquine and malarone. Genetic mutations in crt, dhfr, dhps, and cytochrome b genes conferring drug resistance were also determined for this Peruvian strain of P. falciparum.
Anopheles gambiae Exploits the Treehole Ecosystem in Western Kenya: A New Urban Malaria Risk?
Authors: Omlin Francois X. , Carlson John C. , Ogbunugafor C. Brandon , Hassanali Ahmed
Published: September 2018

At six sites in western Kenya, we explored the presence of Anopheles immature stages in treeholes. An. gambiae larvae were found in 19 species, 13 of which are exotic. The most common exotic species were Delonix regia, Jacaranda mimosipholia, and Eucalyptus citrodora. In Kisumu city, longitudinal assessments of 10 flamboyant trees showed repeated presence of An. gambiae s.s. in treeholes with water. Production of Anopheles larvae did not correlate with habitat volume but with habitat height, showing a strong but statistically insignificant negative correlation. During a dry season, eggs recovered by rinsing dry treeholes hatched into 2.5 ± 3.06 An. gambiae and 7.9 ± 8.2 Aedes larvae. In cage experiments, An. gambiae s.s. laid more eggs in water originating from treeholes than in distilled or lake water, implying preference for ovipositing in this habitat. Our findings indicate that treeholes represent a hitherto unrecognized habitat for malaria vectors, which needs further studies.
Towards an African-Driven Malaria Vaccine Development Program: History and Activities of the African Malaria Network Trust (AMANET)
Authors: Kilama Wen L. , Chilengi Roma , Wanga Charles L.
Published: September 2018

The African Malaria Network Trust (AMANET), whose mission is to promote capacity strengthening of African malaria research institutions, was founded in 2002 and is currently focusing on malaria vaccine development. AMANET has trained over 900 African malaria researchers at workshops relevant to clinical trials of candidate malaria vaccines that will meet scientific, ethical, and international Good Clinical Practice standards. African centers selected for developing malaria vaccines initially undergo a needs assessment, followed by filling gaps in short- and long-term training, provision of essential equipment, and infrastructure improvement. Four centers from different malaria ecoepidemiologic settings are being strengthened; two of these have been approved for carrying out malaria vaccine trials. Researchers from prospective trial sites are mentored at northern institutions undertaking Phase 1a and/or 2a trials; five researchers are undergoing doctoral training. AMANET has sponsored one successful Phase 1b trial; three more are underway. Expert site audits will precede launch of phase 2b trials. Several lessons have been learned: the building of comprehensive capacity, essential for undertaking internationally acceptable trials including their sponsorship, is complex and costly. AMANET has spent over US$ 1 million on capacity strengthening of its leading trial center. Despite the high costs, development of three other sites is underway and there are plans to develop two more sites. To succeed, genuine north–south collaboration based on mutual trust and sharing of available information and responsibilities has been essential. AMANET as a sponsor has assumed roles usually reserved for the pharmaceutical industry, yet is operating where regulatory authorities are generally weak or wanting.
Evidence that the 45-kD Glycoprotein, Part of a Putative Dengue Virus Receptor Complex in the Mosquito Cell Line C6/36, Is a Heat-Shock–Related Protein
Authors: Salas-Benito Juan , Valle Jorge Reyes-Del , Salas-Benito Mariana , Ceballos-Olvera Ivonne , Mosso Clemente , del Angel Rosa M.
Published: September 2018

Dengue virus (DENV) is transmitted to humans by mosquitoes of the genus Aedes. Although several molecules have been described as part of DENV receptor complex in mosquito cells, none of them have been identified. Our group characterized two glycoproteins (40 and 45 kD) as part of the DENV receptor complex in C6/36 cells. Because identification of the mosquito cell receptor has been unsuccessful and some cell receptors described for DENV in mammalian cells are heat-shock proteins (HSPs), the role of HSPs in DENV binding and infection in C6/36 cells was evaluated. Our results indicate that gp45 and a 74-kD molecule (p74), which interact with DENV envelope protein, are immunologically related to HSP90. Although p74 is induced by heat shock, gp45 apparently is not. However, these proteins are relocated to the cell surface after heat-shock treatment, causing an increase in virus binding without any effect on virus yield.
Two Decades of Commitment to Malaria Vaccine Development: GlaxoSmithKline Biologicals
Authors: Ballou W. Ripley , Cahill Conor P.
Published: September 2018

GlaxoSmithKline Biologicals (GSK) is committed to the development of a safe and effective malaria vaccine. Its research program in this field was initiated in 1984 and has been continuously active to this day, making it unparalleled within the vaccine industry. Although it works in partnerships with several leading organizations from the public sector, this effort has required GSK to invest major financial and human resource commitments, and its partners rely heavily on the company’s global infrastructure and expertise in research, advanced clinical development, regulatory, large-scale manufacturing, and commercialization. Through GSK’s pioneering business model and working in partnership with global vaccine funding agencies, the company is committed to seeing that, once approved, a safe and effective malaria vaccine will be available to everyone that needs it.
Spatial Relationship between Adult Malaria Vector Abundance and Environmental Factors in Western Kenya Highlands
Authors: Zhou Guofa , Munga Stephen , Minakawa Noboru , Githeko Andrew K. , Yan Guiyun
Published: September 2018

Information on the spatial relationships between disease vectors and environmental factors is fundamental to vector-borne disease control. Although it is well known that mosquito abundance is associated with the amount of rainfall and thus the number of larval breeding sites, the spatial relationship between larval habitat availability and adult mosquito abundance is not clear. We investigated the impact of environmental heterogeneity and larval habitats on the spatial distribution of Anopheles gambiae s. s. and An. funestus adult mosquitoes, the most important malaria vectors in the highlands of western Kenya. Mosquito sampling was conducted in May, August, and November 2002, and February 2003. Geographic information system layers of larval habitats, land use type, human population distribution, house structure, and hydrologic schemes were overlaid with adult mosquito abundance. Correlography was used to determine the spatial autocorrelation in adult mosquito abundance among houses and the cross-correlation between adult mosquito abundance and environmental factors. Getis’ Gi*(d) index was used to define focal adult mosquito abundance clusters. We found a significant autocorrelation in the vector population and a significant cross-correlation between the vector population and larval habitat availability. The threshold distances of both autocorrelation and cross-correlation were significantly varied among seasons. Focal clustering analysis revealed that the adult vector population was concentrated along the Yala River Valley where most larval habitats were found. Regression analysis found that distance of a house to the Yala River, age of the house, elevation, house structure, and tree canopy coverage significantly affected adult mosquito abundance. Our results suggest that vector control targeted at malaria transmission hotspots and supplemented by larval control may be an effective approach for epidemic malaria control in the western Kenya highlands.
Confirmation of Elimination of Lymphatic Filariasis by an IgG4 Enzyme-Linked Immunosorbent Assay with Urine Samples in Yongjia, Zhejiang Province and Gaoan, Jiangxi Province, People’s Republic of China
Authors: Itoh Makoto , Wu Weiping , Sun Dejian , Yao Linong , Li Zhihong , Islam Mohammad Zahidul , Chen Renyu , Zhang Kunzhao , Wang Fengfei , Zhu Shinan , Kimura Eisaku
Published: September 2018

A sensitive and specific IgG4 enzyme-linked immunosorbent assay (ELISA) with urine samples has been reported. To confirm elimination of bancroftian filariasis, the ELISA was used in a study conducted in Yongjia County and Gaoan City, People’s Republic of China, where filariasis elimination was declared, with 10,409 students 5–16 years of age. The antibody positive rates were 0.08% in Yongjia and 0.34% in Gaoan. All positive samples were re-examined and found to be negative. Our results show that this ELISA is practical and useful for confirmation of the elimination of filariasis. If similar results are obtained in different filariasis-endemic countries, this method may be useful in global filariasis elimination programs.
Comparison of Artemether-Lumefantrine with Sulfadoxine-Pyrimethamine for the Treatment of Uncomplicated Falciparum Malaria in Eastern Nepal
Authors: Thapa Suman , Hollander Judith , Linehan Mary , Cox-Singh Janet , Bista Mahendra B. , Thakur Garib D. , Davis Wendy A. , Davis Timothy M. E.
Published: September 2018

Because available data suggest that resistance of Plasmodium falciparum to sulfadoxine-pyrimethamine (SP) is increasing in Nepal, an open-label, parallel-group efficacy/safety study was conducted in 99 Nepalese patients with uncomplicated falciparum malaria randomized 2:1 to artemetherlumefantrine (AL) or SP. Efficacy was assessed from clinical and microscopic evidence of treatment failure. Four SP-treated patients (12.1%; 95% CI, 4.0–29.1%) redeveloped parasitemia during the 28-day follow-up versus 0% (95% CI, 0–6.9%) in the AL group (P = 0.011), a difference that was confirmed by polymerase chain reaction (PCR) analysis of parasite DNA. PCR detected an additional six patients (two SP and four AL) with sub-microscopic gametocytemia or breakthrough parasitemia between Days 14 and 28, suggesting that AL efficacy was lower than estimated by microscopy. Dhfr and dhps mutations were not associated with outcome. AL is more effective than SP for uncomplicated malaria in Nepal, but regular monitoring of its efficacy should be carried out if this combination therapy is introduced.
Polymerase Chain Reaction Detection of Plasmodium vivax and Plasmodium falciparum DNA from Stored Serum Samples: Implications for Retrospective Diagnosis of Malaria
Authors: Bharti Ajay R. , Patra Kailash P. , Chuquiyauri Raul , Kosek Margaret , Gilman Robert H. , Llanos-Cuentas Alejandro , Vinetz Joseph M.
Published: September 2018

Polymerase chain reaction (PCR) detection of Plasmodium DNA is highly sensitive in diagnosing malaria. The specimen of choice for this assay has been whole blood samples from malaria patients. To retrospectively determine malaria infection rates in populations or cohorts for whom stored serum samples are available, we determined the ability of a nested PCR assay to detect Plasmodium DNA in stored serum samples. The PCR result was positive in 20 of 23 serum samples from patients with microscopy-confirmed malaria and negative in 8 of 8 healthy controls, resulting in a sensitivity of 87% and specificity of 100%. In all positive samples, species were correctly identified by PCR except for one case where a mixed infection was detected. The PCR is able to detect Plasmodium DNA in serum samples frozen up to 2.5 years and has the potential for the retrospective identification of malaria parasitemia in patient cohorts to determine potential interactions of malaria and other diseases such as human immunodeficiency virus/acquired immunodeficiency syndrome.
Predictions of the Impact of Malaria Control Efforts on All-Cause Child Mortality in Sub-Saharan Africa
Authors: Rowe Alexander K. , Steketee Richard W.
Published: September 2018

All-cause childhood mortality (ACCM) has been recommended as an indicator for evaluating the impact of malaria control efforts in parts of Africa where the malaria burden is high and vital registration systems are weak. As ACCM is not malaria-specific, we explored the relationship between ACCM and malaria mortality. First, we show that if malaria mortality is reduced by 50% in populations exposed to high-intensity malaria transmission, ACCM is predicted to decrease by ≈ 17% (plausible values range from 12% to 25%). Second, if malaria interventions are scaled-up from very low (2%) to reasonably high coverage levels (70%), epidemiologic models predict that ACCM would decrease by ≈ 17% or 18% (precision estimate: 15–19%). These results suggest that if malaria interventions are scaled-up to reach or exceed 70% coverage, it is plausible that a goal of reducing malaria mortality by 50% could be achieved. It is also likely that a pair of “typical”-size mortality surveys could detect this ACCM change as being statistically significant. Although existing models have important limitations, they could be improved by incorporating empirical results during scale-up of multiple interventions and by adding precision estimates and sensitivity analyses.
Mycoplasma gallisepticum Infection in House Finches (Carpodacus mexicanus) Affects Mosquito Blood Feeding Patterns
Authors: Darbro Jonathan M. , Dhondt André A. , Vermeylen Françoise M. , Harrington Laura C.
Published: September 2018

Disease-induced lethargy can diminish host capacity to repel or kill biting mosquitoes. We exposed house finches (Carpodacus mexicanus) to mosquitoes (Culex pipiens pipiens), repeated the experiment after inoculating finches with Mycoplasma gallisepticum, and then repeated the experiment with the same birds after curing their infections. We videotaped avian behaviors before and during mosquito exposure, identifying hosts through blood meal DNA fingerprinting. Results revealed heterogeneity in mosquito preference regardless of infection. Mosquitoes choosing between two healthy finches were more likely to feed upon the same individual bird consistently. When one bird was sick, mosquitoes exhibited no preference. Sick birds made fewer total defensive behaviors than healthy birds, but only foot stomps were associated with reduced mosquito feeding success. Our results suggest that Mycoplasma and other avian infections that alter bird defensive behavior may influence mosquito feeding patterns and transmission of arthropod-borne pathogens such as West Nile virus.
Echinococcus multilocularis Infection of Several Old World Monkey Species in a Breeding Enclosure
Authors: Tappe Dennis , Brehm Klaus , Frosch Matthias , Blankenburg Anja , Schrod Annette , Kaup Franz-Josef , Mätz-Rensing Kerstin
Published: September 2018

Echinococcus multilocularis, the causative agent of alveolar echinococcosis, is spreading geographically in Europe, and prevalence rates in foxes, the final host, are increasing. Concomitantly, the rate of newly diagnosed human infections has already doubled in Germany. We report a cluster of alveolar echinococcosis in 24 animals of different Old World monkey species (15 cynomolgus monkeys, 5 rhesus monkeys, and 4 lion-tailed macaques) in northern Germany. The cluster described is the largest ever recorded in a single center. Cynomolgus monkeys were very susceptible and constituted the monkey species at highest risk, indicating that this species could act as a sentinel animal for the transmission of alveolar echinococcosis in zoological gardens or similar institutions.
Coinfection with Leptospirosis and Scrub Typhus in Taiwanese Patients
Authors: Lee Chen-Hsiang , Liu Jien-Wei
Published: September 2018

We retrospectively analyzed patients with leptospirosis (n = 35), scrub typhus (n = 45), and coinfection (leptospirosis and scrub typhus [n = 7]) to facilitate the detection of coinfection. Our data showed that factors favoring these disease entities included animal contact, an aspartate aminotransferase/alanine aminotransferase ratio > 2 (for leptospirosis); outdoor exposure, lymphadenopathy, splenomegaly, eschar, and elevated alkaline phosphatase levels (for scrub typhus and coinfection); calf tenderness, conjunctival suffusion, jaundice, oliguria, elevated total bilirubin levels and serum creatinine levels (for leptospirosis and coinfection); and maculopapular rash (for scrub typhus). Patients at risk for leptospirosis are often at increased risk for scrub typhus and vice versa. Lack of knowledge of coinfection may jeopardize the health of affected patients. Our study serves as a reminder of potential coinfection and provides clues for its detection.
Clinical Intervention and Molecular Characteristics of a Dengue Hemorrhagic Fever Outbreak in Timor Leste, 2005
Authors: Kalayanarooj Siripen , Rimal Hem Sagar , Andjaparidze Alex , Vatcharasaevee Varunee , Nisalak Ananda , Jarman Richard G. , Chinnawirotpisan Piyawan , Mammen Mammen P. , Holmes Edward C. , Gibbons Robert V.
Published: September 2018

In response to a January 2005 report of dengue hemorrhagic fever (DHF) in Timor Leste, the World Health Organization sent a team to assist the National Hospital Guido Valadares (NHGV) in Dili with clinical case management and diagnostic support. The hospital reported 67 admissions including 8 deaths (case fatality rate approximately 12%) over the previous weeks with case histories clinically compatible with DHF. During the intervention, an additional 44 suspected dengue patients were admitted to the pediatric ward of NHGV. Among 41 patients with clinical diagnoses of dengue fever or DHF, 38 (93%) were laboratory confirmed. Although cause and effect cannot be definitely attributed, the case fatality rate decreased to 3.6% after the intervention with education about dengue management strategies.
Clinical Trial of an F(ab’)2 Polyvalent Equine Antivenom for African Snake Bites in Benin
Authors: Chippaux J.-P. , Massougbodji A. , Stock R. P. , Alagon A. , _ _
Published: September 2018

We report the results of a trial designed to measure the safety and efficacy of African Antivipmyn®, a new freeze-dried polyvalent equine F(ab’)2-based antivenom. We tested 289 envenomations. After treatment, 19% of treated patients had undesirable events, all benign. A possible adverse effect was attributed to this antivenom in 11% of the patients. Bleeding was observed in 48% of the patients; it stopped within 2 hours after treatment with antivenom in 60% of the patients. Blood incoagulability was observed in 80% of the patients. Restoration of coagulation was attained within 4 hours in 60% of the patients. Nine patients died; 6 arrived at the hospital in the final stage of complications and 5 arrived at the hospital more than 60 hours after the bite. The value of blood coagulation tests in diagnosis of envenomation and bleeding as an indicator of renewal of treatment are emphasized.
A Real-Time TaqMan Polymerase Chain Reaction for the Identification of Culex Vectors of West Nile and Saint Louis Encephalitis Viruses in North America
Authors: Sanogo Yibayiri O. , Kim Chang-Hyun , Lampman Richard , Novak Robert J.
Published: September 2018

In North America, West Nile and St. Louis encephalitis viruses have been detected in a wide range of vector species, but the majority of isolations continue to be from pools of mixed mosquitoes in the Culex subgenus Culex. Unfortunately, the morphologic identification of these important disease vectors is often difficult, particularly in regions of sympatry. We developed a sensitive real-time TaqMan polymerase chain reaction assay that allows reliable identification of Culex mosquitoes including Culex pipiens pipiens, Cx. p. quinquefasciatus, Cx. restuans, Cx. salinarius, Cx. nigripalpus, and Cx. tarsalis. Primers and fluorogenic probes specific to each species were designed based on sequences of the acetylcholinesterase gene (Ace2). Both immature and adult mosquitoes were successfully identified as individuals and as mixed species pools. This identification technique provides the basis for a rapid, sensitive, and high-throughput method for expounding the species-specific contribution of vectors to various phases of arbovirus transmission.
Seropositive Human Subjects Produce Interferon Gamma after Stimulation with Recombinant Cryptosporidium hominis gp15
Authors: Preidis Geoffrey A. , Wang Heuy-Ching , Lewis Dorothy E. , Castellanos-Gonzalez Alejandro , Rogers Kathleen A. , Graviss Edward A. , Ward Honorine D. , White A. Clinton
Published: September 2018

Cryptosporidiosis is an important cause of diarrhea worldwide. In normal hosts, infection is self-limited and associated with seroconversion and partial immunity to reinfection. Immunity is associated with interferon gamma (IFNγ) production. Cryptosporidium surface proteins gp15 and gp40 are among the immunodominant proteins in terms of antibody responses. We asked the question of whether these antigens also stimulate production of IFNγ in patients who have serologic evidence of prior infection. Whole blood from seropositive donors was stimulated with recombinant gp15 and gp 40 from Cryptosporidium hominis and Cryptosporidium parvum or His-tag controls. C. hominis gp15 stimulated increased production of IFNγ. By contrast, there was no significant increase after stimulation with C. parvum gp15 or either gp40 preparation. IFNγ production in response to C. hominis gp15 was noted in both CD4+ and CD8+ cells. This highlights the potential for C. hominis gp15 as a vaccine candidate for human cryptosporidiosis.
A Critical Appraisal of Molecular Xenomonitoring as a Tool for Assessing Progress toward Elimination of Lymphatic Filariasis
Authors: Farid Hoda A. , Morsy Zakariya S. , Helmy Hanan , Ramzy Reda M. R. , El Setouhy Maged , Weil Gary J.
Published: September 2018

We used molecular xenomonitoring (MX, detection of filarial DNA in mosquitoes) to evaluate the impact of mass drug administration (MDA) in sentinel locations in Egypt with high (11.5%) and low (4.1%) baseline microfilaria prevalence rates. Blood-fed Culex pipiens were pooled by household and tested for Wuchereria bancrofti DNA by PCR. There was no significant relationship between the infection status of household residents and parasite DNA status of mosquitoes from the same houses. After 5 MDA rounds, parasite DNA rates in mosquitoes in high- and low-prevalence areas were reduced by 93.8% and 100% to 0.19% (95% CI: 0.076–0.382%) and 0% (95% CI: 0–0.045%), respectively. These changes were consistent with decreases in microfilaria prevalence rates in these sites; they provide insight regarding the minimal mosquito DNA rates necessary for sustained transmission of filariasis in Egypt. We conclude that MX is a powerful tool for monitoring the impact of MDA on filariasis endemicity and transmission.
Plasma Vascular Endothelial Growth Factor-A (VEGF-A) and VEGF-A Gene Polymorphism are Associated with Hydrocele Development in Lymphatic Filariasis
Authors: Debrah Alexander Yaw , Mand Sabine , Toliat Mohammad Reza , Marfo-Debrekyei Yeboah , Batsa Linda , Nürnberg Peter , Lawson Bernard , Adjei Ohene , Hoerauf Achim , Pfarr Kenneth
Published: September 2018

Hydrocele is a build-up of fluid in the scrotal regions of a proportion of men infected with the filarial nematode Wuchereria bancrofti. Vascular endothelial growth factors (VEGF) are major mediators of vascular permeability and angiogenesis in the development and progression of many diseases, making them candidates in hydrocele development. We assessed the role of VEGF-A genetic polymorphisms in hydrocele development in a cohort of lymphatic filariasis patients from Ghana. Three VEGF-A promoter polymorphisms were examined. The C/C genotype at −460 was significantly higher in hydrocele patients ([P = 0.0007], OR = 3.8 [95% CI = 1.9–8.2]) than in non-hydrocele patients. Furthermore, plasma levels of VEGF-A were significantly higher in subjects with the C/C genotype than in those with other genotypes. Also, a positive correlation (R2 = 0.412, P = 0.026) was observed between plasma VEGF-A and stage of hydrocele. The data suggest that the C polymorphism at −460 is a genetic risk factor for hydrocele development in lymphatic filariasis.
Malaria Stratification, Climate, and Epidemic Early Warning in Eritrea
Authors: Ceccato Pietro , Ghebremeskel Tewolde , Jaiteh Malanding , Graves Patricia M. , Levy Marc , Ghebreselassie Shashu , Ogbamariam Andom , Barnston Anthony G. , Bell Michael , del Corral John , Connor Stephen J. , Fesseha Issac , Brantly Eugene P. , Thomson Madeleine C.
Published: September 2018

Eritrea has a successful malaria control program, but it is still susceptible to devastating malaria epidemics. Monthly data on clinical malaria cases from 242 health facilities in 58 subzobas (districts) of Eritrea from 1996 to 2003 were used in a novel stratification process using principal component analysis and nonhierarchical clustering to define five areas with distinct malaria intensity and seasonality patterns, to guide future interventions and development of an epidemic early warning system. Relationships between monthly clinical malaria incidence by subzoba and monthly climate data from several sources, and with seasonal climate forecasts, were investigated. Remotely sensed climate data were averaged over the same subzoba geographic administrative units as the malaria cases. Although correlation was good between malaria anomalies and actual rainfall from ground stations (lagged by 2 months), the stations did not have sufficiently even coverage to be widely useful. Satellite derived rainfall from the Climate Prediction Center Merged Analysis of Precipitation was correlated with malaria incidence anomalies, with a lead time of 2–3 months. NDVI anomalies were highly correlated with malaria incidence anomalies, particularly in the semi-arid north of the country and along the northern Red Sea coast, which is a highly epidemic-prone area. Eritrea has 2 distinct rainy seasons in different parts of the country. The seasonal forecasting skill from Global Circulation Models for the June/July/August season was low except for the Eastern border. For the coastal October/November/December season, forecasting skill was good only during the 1997–1998 El Niño event. For epidemic control, shorter-range warning based on remotely sensed rainfall estimates and an enhanced epidemic early-detection system based on data derived for this study are needed.
Persistent and Untreated Tropical Infectious Diseases Among Sudanese Refugees in the United States
Authors: Franco-Paredes Carlos , Dismukes Roberta , Nicolls Deborah , Hidron Alicia , Workowski Kimberly , Rodriguez-Morales Alfonso , Wilson Marianna , Jones Danielle , Manyang Peter , Kozarsky Phyllis
Published: September 2018

A comprehensive medical evaluation to identify persistent and untreated tropical infections among members of the Sudanese group “Lost Boys of Sudan” living in Atlanta, GA, was initiated. Medical examinations and laboratory testing including blood cell counts, liver function tests, stool studies for parasites, hepatitis B serologies, and serologic testing for Schistosoma spp., Strongyloides, and filariae were performed. Preliminary results showed a high prevalence of untreated active schistosomiasis and strongyloidiasis infections in this group, 5 years after their resettlement in the United States. In addition, we found that many of them were infected with onchocerciasis and hepatitis B. We suggest that based on these preliminary results, pre-departure presumptive treatment and/or testing algorithms need to address some of these persistent tropical infections.
Life-Table Analysis of Anopheles arabiensis in Western Kenya Highlands: Effects of Land Covers on Larval and Adult Survivorship
Authors: Afrane Yaw A. , Zhou Goufa , Lawson Bernard W. , Githeko Andrew K. , Yan Guiyun
Published: September 2018

In high-elevation areas in western Kenya, the abundance of Anopheles arabiensis is either very low or absent. The western Kenya highlands (an area with an elevation > 1,500m above sea level) have also been experiencing extensive deforestation, and deforestation has been suggested as one of the important factors that facilitate malaria transmission in the highlands. This study investigated whether climate conditions in the western Kenya highlands (Kakamega, elevation 1,500 m above sea level) were permissive to the development and survival of An. arabiensis and whether deforestation promoted An. arabiensis survivorship of immature and adult stages, using life-table analysis. We found that in larval habitats located in forested areas, only 4–9% of first-instar larvae developed into adults and the development length exceeded 20 days. Mean water temperature of aquatic habitats in the deforested area was 4.8–6.1°C higher than that in the forested area, larval-to-adult survivorship was increased to 65–82%, and larval-to-adult development time was shortened by 8–9 days. The average indoor temperature in houses in the deforested area was 1.7–1.8°C higher than in the forested area, and the relative humidity was 22–25% lower. The median survival time of adult mosquitoes in the deforested area was 49–55% higher than those in the forested area. The net reproductive rate of female mosquitoes in the deforested area was 1.7- to 2.6-fold higher than that in the forested area. Compared with previously published data on An. gambiae, the net reproductive rate of An. arabiensis was only 0.8–1.3% of Anopheles gambiae in the forested area and 2.3–2.6% in the deforested area. Therefore, the current ambient climate condition is less permissive to An. arabiensis than to An. gambiae in western Kenya highlands. However, environmental changes such as deforestation and global warming may facilitate the establishment of An. arabiensis populations in the highlands.
Discrimination of Seven Anopheles Species from San Pedro de Urabá, Antioquia, Colombia, by Polymerase Chain Reaction–Restriction Fragment Length Polymorphism Analysis of Its Sequences
Authors: Zapata Mario A. , Cienfuegos Astrid V. , Quirós Oscar I. , Quiñones Martha L. , Luckhart Shirley , Correa Margarita M.
Published: September 2018

Accurate identification of anopheline species is essential for vector incrimination and implementation of appropriate control strategies. Several anopheline species are considered important malaria vectors in Colombia; however, species determination is complicated by cryptic morphology and intra-individual variation. We describe polymerase chain reaction–restriction fragment length polymorphism (PCR-RFLP) of internal transcribed spacer 2 (ITS2) sequences for differentiation of seven Anopheles species collected in a locality in Antioquia, Colombia, with high levels of malaria transmission. Each of these seven species can be identified by unique AluI PCR-RFLP restriction patterns. Comparisons of morphologic identification with molecular identification of voucher specimens confirmed species designation for 886 wild-caught anophelines. This new method can be used as a diagnostic tool for discrimination of anopheline species of medical importance in this region, some of which have overlapping morphologic characters and for conducting complementary studies where rapid and accurate identification of large numbers of specimens is needed.
Recent Change of the Antigenicity and Genotype of Japanese Encephalitis Viruses Distributed on Okinawa Island, Japan
Authors: Saito Mika , Taira Katsuya , Itokazu Kiyomasa , Mori Naoki
Published: September 2018

In this study, five isolates of Japanese encephalitis virus (JEV) were obtained from swine serum samples collected on Okinawa Island, Japan, between 2002 and 2003. All five JEV isolates belonged to genotype 1, and JEV isolates obtained from the island before 1992 were genotype 3. Genotype 1 was known to be distributed from northern Thailand to Cambodia and recently expanded to Australia, Vietnam, the Republic of Korea, and Japan. However, phylogenetic analysis showed that the source of the newly emerging genotype 1 in Asia is different from that in Australia. Sero-epidemiologic investigations showed that serum samples collected from 1985 to 1988 from JEV-immune swine neutralized both the Naha Meat 54 strain (1985 JEV Okinawan isolate from swine, genotype 3) and the Oki 431S strain (2002 JEV Okinawan isolate from swine, genotype 1), and many samples collected in 2002 neutralized the Oki 431S strain but not the Naha Meat 54 strain. These results strongly suggest that the genotype and antigenicity of JEV on Okinawa Island have changed significantly over the past decade.
Invasive Pneumococcal Disease Burden and Implications for Vaccine Policy in Urban Bangladesh
Authors: Brooks W. Abdullah , Breiman Robert F. , Goswami Doli , Hossain Anowar , Alam Khorshed , Saha Samir K. , Nahar Kamrun , Nasrin Dilruba , Ahmed Noor , El Arifeen Shams , Naheed Aliya , Sack David A. , Luby Stephen
Published: September 2018

We undertook active population-based surveillance in 5,000 urban households among children < 5 years old to determine invasive pneumococcal disease (IPD) incidence, serotype distribution, clinical presentation, and antimicrobial resistance, which have not been previously described in population-based studies from the region. IPD was documented by blood culture isolation. From 01 April 2004 to 31 March 2006, 5,903 blood cultures were collected from 6,167 eligible children. Streptococcus pneumoniae was isolated from 34 pneumococcal patients; IPD was clinically associated with pneumonia (24%), upper respiratory infection (62%), and febrile syndromes (14%). Overall, IPD and 13-valent serotype–related IPD incidences were 447 and 276 episodes/100,000 child-years, respectively. Peak IPD incidence occurred during the cool dry seasons. Penicillin, cotrimoxazole, chloramphenicol, and ciprofloxacin resistances were 2.9%, 82.4%, 14.7%, and 24.1%, respectively. Current conjugate vaccines should substantially reduce IPD, childhood pneumonia, and antimicrobial resistance in Bangladesh.
Seroprevalence of Entamoeba histolytica Infection in HIV-Infected Patients in China
Authors: Chen Yi , Zhang Yunzhi , Yang Bin , Qi Tangkai , Lu Hongzhou , Cheng Xunjia , Tachibana Hiroshi
Published: September 2018

Seroprevalence of Entamoeba histolytica infection in HIV-infected individuals from Shanghai city, Anhui province, and Henan province, China, was examined by enzyme-linked immunosorbent assay using crude antigen and a recombinant surface antigen, C-Igl, of the parasite. In 215 HIV-infected individuals, the positive rates for these antigens were 12.1% and 7.9%, respectively; these rates were significantly higher than the rates of 3.1% and 0.5%, respectively, in 191 patients with gastrointestinal symptoms who were not infected with HIV. There was no significant difference in seropositivity to E. histolytica between men and women. Seropositivity in HIV-infected individuals was higher in patients with a CD4+ T cell count of < 200/μL. This is the first report showing a higher seroprevalence of E. histolytica infection in HIV-infected patients in China. Our results also suggest that HIV infection is a risk factor for infection with E. histolytica.
Description of the First Reported Human Case of Spotted Fever Group Rickettsiosis in Urban Bangkok
Authors: Sangkasuwan Vichai , Chatyingmongkol Thongchai , Sukwit Suchitra , Eamsila Chirapa , Chuenchitra Thippawan , Rodkvamtook Wuttikorn , Jiang Ju , Richards Allen L. , Lerdthusnee Kriangkrai , Jones James W.
Published: September 2018

Described herein is the clinical presentation of a patient from Bangkok, with fever, petechial rash, history of a tick bite, and a diagnosis of spotted fever rickettsiosis.
Application of Mosquito Sampling Count and Geospatial Methods to Improve Dengue Vector Surveillance
Authors: Chansang Chitti , Kittayapong Pattamaporn
Published: September 2018

Dengue hemorrhagic fever is a major public health problem in several countries around the world. Dengue vector surveillance is an important methodology to determine when and where to take the control action. We used a combination of the Global Positioning System (GPS)/Geographic Information System (GIS) technology and the immature sampling count method to improve dengue vector surveillance. Both complete count and sampling count methods were used simultaneously to collect immature dengue vectors in all houses and all containers in one village in eastern Thailand to determine the efficiency of the sampling count technique. A hand-held GPS unit was used to record the location of surveyed houses. Linear regression indicated a high correlation between total immature populations resulting from the complete count and estimates from sampling count of immature stages. The immature survey data and the GPS coordinates of house location were combined into GIS maps showing distribution of immature density and clustering of immature stages and positive containers in the study area. This approach could be used to improve the efficiency and accuracy of dengue vector surveillance for targeting vector control.
Platelet-Mediated Clumping of Plasmodium falciparum–Infected Erythrocytes Is Associated with High Parasitemia but Not Severe Clinical Manifestations of Malaria in African Children
Authors: Arman Mònica , Raza Ahmed , Tempest Louisa J. , Lyke Kirsten E. , Thera Mahamadou A. , Koné Abdoulaye , Plowe Christopher V. , Doumbo Ogobara K. , Rowe J. Alexandra
Published: September 2018

Platelet-mediated clumping of Plasmodium falciparum–infected erythrocytes is an adhesive phenotype commonly found in field isolates that has previously been associated with severe malaria. Here, clumping was assessed in 131 isolates from Malian children. The clumping phenotype was seen in 6% (N = 51) of uncomplicated malaria, 24% (N = 51) of severe malaria, and 45% (N = 29) of high parasitemia non-severe malaria isolates. Multivariate analysis indicated that clumping was strongly positively associated with parasitemia (F1,122 = 24.1, P < 0.001) but not with disease category (F2,122 = 1.8, P = 0.17). Therefore platelet-mediated clumping in Malian P. falciparum isolates is primarily associated with high parasitemia and not with severe clinical manifestations of malaria.
First Case of Indigenous Visceral Leishmaniasis from Central India
Authors: Dey Ayan , Sharma Umakant , Singh Sarman
Published: September 2018

Visceral leishmaniasis is endemic in the eastern states of India, but central India remains free of leishmaniais. This report describes the first indigenous case of visceral leishmaniasis in a seven-year-old girl from central India. The child presented with fever for 10 days and was diagnosed by bone marrow examination, serology using rKE16 and rK39 antigens, and a polymerase chain reaction specific for the kinesin gene. Sequencing of the immunodominant region of the kinesin gene of the parasite showed four tandem repeats, each 117 basepairs. The first tandem repeat of this strain had 97% homology with the corresponding first tandem repeat of the Leishmania donovani KE16 strain and 92% homology with the L. chagasi BA-2 strain. The second, third, and fourth tandem repeats had 97%, 98%, and 99% homology, respectively, with the L. donovani KE16 strain, and 89%, 96%, and 92% homology, respectively, with the L. chagasi BA-2 strain. This case shows that more than one genetic variant of L. donovani is circulating in various parts of India.
Differential Antibody Responses to Plasmodium falciparum Invasion Ligand Proteins in Individuals Living in Malaria-Endemic Areas in Brazil and Cameroon
Authors: Ford Louise , Lobo Cheryl A. , Rodriguez Marilis , Zalis Mariano G. , Machado Ricardo L. D. , Rossit Andréa R. B. , Cavasini Carlos E. , Couto Alvaro A. R. , Enyong Peter A. , Lustigman Sara
Published: September 2018

Antibody responses to malaria invasion ligands and proteins on the merozoite surface have been shown to interfere with red cell invasion and correlate with immunity to malaria. The current study is the first to characterize the antibody responses to EBA-140 and EBA-181, Plasmodium falciparum invasion ligands implicated in the alternative pathways of invasion, in age-matched populations of individuals living in endemic areas in both Brazil and Cameroon. Antibody responses to the proteins screened were different between populations. The African individuals reacted strongly with most fragments of these two EBAs, while the majority of the individuals from Mato Grosso, Brazil, reacted weakly and those from the Amazon had elevated responses to these EBA proteins. When compared with the responses against MSP-119 and EBA-175, it appeared that the Brazilian population has a variable ability to recognize P. falciparum invasion ligand proteins and that these responses are distinct from the African population.
Efficacy of Azithromycin versus Systemic Meglumine Antimoniate (Glucantime) in the Treatment of Cutaneous Leishmaniasis
Authors: Layegh Pouran , Yazdanpanah Mohammad Javad , Vosugh Elham Mohammadi , Pezeshkpoor Fakhrozaman , Shakeri Mohamad Taghi , Moghiman Toktam
Published: September 2018

Cutaneous leishmaniasis (CL) treatment is painful, and cosmetic results are often unsatisfying. Azithromycin has been reported to be effective in treatment of CL caused by Leishmania viannia braziliensis. The efficacy of azithromycin was compared with Glucantime in treatment of Old World leishmaniasis. Of 49 patients, 22 received 500 mg/day azithromycin for 5 days/month. Treatment cycles were repeated monthly to a maximum of 4 months; 27 patients received 60 mg/kg intramuscular meglumine antimoniate for 20 days. Both groups were followed up for 16 weeks. In the azithromycin group, 2 patients withdrew because of GI symptoms. The response rates of 20 patients (29 lesions) were as follows: full improvement, 10.3%; partial improvement, 27.6%; and 62.1%, no response. In the glucantime group with 27 patients (58 lesions), these rates were 34.4%, 13.8%, and 51.7%, respectively (P = 0.036). Azithromycin was determined to be not as effective as Glucantime in treatment of Old World CL.
Laboratory-based Japanese Encephalitis Surveillance in Nepal and the Implications for a National Immunization Strategy
Authors: Wierzba Thomas F. , Ghimire Prakash , Malla Sarala , Banerjee Manas Kumar , Shrestha Sanjaya , Khanal Basudha , Sedai Tika R. , Gibbons Robert V.
Published: September 2018

We report on two years of Japanese encephalitis (JE) surveillance in Nepal and the implications for a national immunization strategy. From May 2004 to April 2006, 4,652 patients with encephalitis were evaluated. A serum or cerebrospinal fluid specimen was collected from 3198 (69%) patients of which 1,035 (32%) were positive by Japanese encephalitis IgM ELISA. Most cases (N = 951, 92%) were from the 24 Terai districts (i.e., southern plains, 12.3 million persons) with the majority (N =616, 65%) from four western Terai districts (population =1.8 million). The case fatality ratio was 14.7% and 6.3% and the proportion of cases under 15 years old was 52% and 62% in the four western and 20 non-western Terai districts, respectively. Japanese encephalitis immunization targeting residents one year of age and older in the western districts and one through 14 years old in the non-western Terai districts may have reduced Japanese encephalitis cases by 84% and deaths by 92%, nationally.
Detection of Japanese Encephalitis Virus Antibodies in Bats in Southern China
Authors: Cui Jie , Counor Dorian , Shen Di , Sun Guya , He Hongxuan , Deubel Vincent , Zhang Shuyi
Published: September 2018

In this study, 336 bats of eight species were collected during 2004–2007 in six provinces of Southern China. Antibodies against Japanese encephalitis virus (JEV) were detected by ELISA in 43 of 336 (12.8%) serum samples. Among those ELISA-positive samples, 11 serum samples had neutralizing antibodies against JEV. No JEV was detected in brain and liver samples using specific real-time reverse transcriptase-polymerase chain reaction. This is the first report of JEV neutralizing antibodies in bats in China, which reinforces that bats can be involved in the life cycle of this virus.
A Real-Time Polymerase Chain Reaction Assay for the Identification and Quantification of American Leishmania Species on the Basis of Glucose-6-Phosphate Dehydrogenase
Authors: Castilho Tiago Moreno , Camargo Luís Marcelo Aranha , McMahon-Pratt Diane , Shaw Jeffrey Jon , Floeter-Winter Lucile Maria
Published: September 2018

A real-time polymerase chain reaction (PCR) test was developed on the basis of the Leishmania glucose-6-phosphate dehydrogenase locus that enables identification and quantification of parasites. Using two independent pairs of primers in SYBR-Green assays, the test identified etiologic agents of cutaneous leishmaniasis belonging to both subgenera, Leishmania (Viannia) and Leishmania (Leishmania) in the Americas. Furthermore, use of TaqMan probes enables distinction between L. (V.) braziliensis or L. (V.) peruviania from the other L. (Viannia) species. All assays were negative with DNA of related trypanosomatids, humans, and mice. The parasite burden was estimated by normalizing the number of organisms per total amount of DNA in the sample or per host glyceraldehyde-3-phosphate dehydrogenase copies. The real-time PCR assay for L. (Leishmania) subgenus showed a good linear correlation with quantification on the basis of a limiting dilution assay in experimentally infected mice. The test successfully identifies and quantifies Leishmania in human biopsy specimens and represents a new tool to study leishmaniasis.