bluuebunny/crossref_metadata_2025 huggingface dataset:
URBANIZATION IN SUB-SAHARAN AFRICA AND IMPLICATION FOR MALARIA CONTROL
Authors: KEISER JENNIFER , UTZINGER JÜRG , DE CASTRO MARCIA CALDAS , SMITH THOMAS A. , TANNER MARCEL , SINGER BURTON H.
Published: September 2018

Malaria not only remains a leading cause of morbidity and mortality, but it also impedes socioeconomic development, particularly in sub-Saharan Africa. Rapid and unprecedented urbanization, going hand-in-hand with often declining economies, might have profound implications for the epidemiology and control of malaria, as the relative disease burden increases among urban dwellers. Reviewing the literature and using a modeling approach, we find that entomologic inoculation rates in cities range from 0 to 54 per year, depending on the degree of urbanization, the spatial location within a city, and overall living conditions. Using the latest United Nations figures on urbanization prospects, nighttime light remotely sensed images, and the “Mapping Malaria Risk in Africa” results on climate suitability for stable malaria transmission, we estimate that 200 million people (24.6% of the total African population) currently live in urban settings where they are at risk of contracting the disease. Importantly, the estimated total surface area covered by these urban settings is only approximately 1.1–1.6% of the total African surface. Considering different plausible scenarios, we estimate an annual incidence of 24.8–103.2 million cases of clinical malaria attacks among urban dwellers in Africa. These figures translate to 6–28% of the estimated global annual disease incidence. Against this background, basic health care delivery systems providing early diagnosis and early treatment and preventive actions through mother and child health programs and the promotion of insecticide-treated bed nets for the rapidly growing numbers of the urban poor must be improved alongside well-tailored and integrated malaria control strategies. We propose environmental management and larviciding within well-specified productive sites as a main feature for such an integrated control approach. Mitigation of the current burden of malaria in urban African settings, in turn, is a necessity for stimulating environmentally and socially sustainable development.
REAL-TIME REVERSE TRANSCRIPTASE–POLYMERASE CHAIN REACTION QUANTIFICATION OF WEST NILE VIRUS TRANSMITTED BY CULEX PIPIENS QUINQUEFASCIATUS
Authors: VANLANDINGHAM DANA L. , SCHNEIDER BRADLEY S. , KLINGLER KIMBERLY , FAIR JOSEPH , BEASLEY DAVID , HUANG JING , HAMILTON PATRICIA , HIGGS STEPHEN
Published: September 2018

Transmission experiments are a critical component of vector competence studies. In this study, a real-time reverse transcriptase-polymerase chain reaction (RT-PCR) was used to enumerate the amount of West Nile virus (WNV) secreted in mosquito saliva following oral infection. Culex pipiens quinquefasciatus were allowed to feed on WNV-infected blood, and saliva was collected on days 14 and 21 post-infection (pi). The amount of virus at these two time points varied significantly, with mean equivalent plaque-forming units (pfu) of approximately 30,500 on day 14 pi and 5,800 on day 21 pi. Individual mosquitoes secreted up to 2 × 105 pfu of virus. Titer of whole mosquitoes and immunofluorescence assay of salivary glands from mosquitoes collected at these two time points were also used for supplemental comparison. This report describes the first use of a real-time RT-PCR to quantify the amount of WNV in mosquito saliva.
HUMAN IMMUNODEFICIENCY VIRUS TYPE 1 AND OTHER VIRAL CO-INFECTIONS AMONG YOUNG HETEROSEXUAL MEN AND WOMEN IN ARGENTINA
Authors: DE LOS ANGELES PANDO MARÍA , BIGLIONE MIRNA M. , TOSCANO MAURO FERNÁNDEZ , REY JORGE A. , RUSSELL KEVIN L. , NEGRETE MONICA , GIANNI SILVIA , MARTINEZ-PERALTA LILIANA , SALOMÓN HORACIO , SOSA-ESTANI SERGIO , MONTANO SILVIA M. , OLSON JAMES G. , SANCHEZ JOSÉ L. , CARR JEAN K. , ÁVILA MARIA M.
Published: September 2018

Infections with hepatitis C virus, (HCV), hepatitis B virus (HBV), and human T lymphotropic type I/II (HTLV-I/II) virus are commonly found in patients infected with human immunodeficiency virus type 1 (HIV-1). We conducted a seroepidemiologic study among 174 HIV-positive heterosexuals in Buenos Aires, Argentina in 1999. Evidence of exposure to HCV, HBV, and HTLV-I/II was found in 32%, 17%, and 5%, respectively. A higher prevalence of HBV infection was observed among males (33%) compared with females (12%; P < 0.05). Among women, a prior history of a sexually transmitted infection, injecting drug use (IDU), having had more than five lifetime sex partners, and having exchanged sex-for-goods were significantly associated with HCV infection, whereas an IDU history, syringe sharing, and having exchanged sex-for-goods were found to be associated with HBV infection. Among men, an IDU history and syringe/needle sharing were significantly associated with HCV infection. The IDU-related and sexual transmission of hepatitis viruses constitute a significant problem among young, HIV-infected, heterosexuals in Argentina.
PUBLIC AND PRIVATE ROLES IN MALARIA CONTROL: THE CONTRIBUTIONS OF ECONOMIC ANALYSIS
Authors: HANSON KARA
Published: September 2018

There has been high profile advocacy and debate about how to increase availability and uptake of effective malaria control interventions. Application of the tools of public economics indicates that market failures occur for a number of effective malaria control interventions due to monopoly, externalities, and information failures, implying a role for public action. However, additional analysis is required to determine the optimal form of public intervention, and how to set priorities. Additional criteria of cost-effectiveness, impact on poverty and catastrophic expenditures, affordability, characteristics of supply and demand, and potential for leakage are invoked to help inform decision making in the field of malaria control policies. Particular emphasis is placed on the connections between public and private actions.
ACT NOW OR LATER? ECONOMICS OF MALARIA RESISTANCE
Authors: LAXMINARAYAN RAMANAN
Published: September 2018

In the past, malaria control efforts in sub-Saharan Africa have relied on a combination of vector control with effective treatment using chloroquine. With increasing resistance to chloroquine, attention has now turned to alternative treatment strategies to replace this failing drug. Some countries have already changed their official first-line treatment to sulfadoxine-pyrimethamine, while others are contemplating a switch to artemisinin-based combination treatments (ACTs). Although there are strong theoretical arguments in favor of switching to ACTs, the validity of these arguments in the face of financial constraints has not been previously analyzed. In this report, we use a bioeconomic model of malaria transmission and evolution of drug resistance to examine questions of optimal treatment strategy and coverage when drug resistance places an additional constraint on choices available to the policymaker.
THE GLOBAL EPIDEMIOLOGY, SYNDROMIC CLASSIFICATION, MANAGEMENT, AND PREVENTION OF SPIDER BITES
Authors: DIAZ JAMES H.
Published: September 2018

Spiders are carnivorous arthropods that coexist with humans and ambush or ensnare prey. Unlike other arthropods, spiders rarely transmit communicable diseases, and play a critical role in the ecosystem by consuming other arthropods that frequently transmit human diseases, such as mosquitoes and flies. There are more than 30,000 species of spiders, most of which are venomous, but they cannot inflict serious bites due to delicate mouthparts and short fangs. The differential diagnosis of spider bites is extensive and includes other arthropod bites, skin infections, and exposure to chemical or physical agents. However, approximately 200 species from 20 genera of spiders worldwide can cause severe human envenomings, with dermonecrosis, systemic toxicity, and death. Spider bites can usually be prevented by simple personal and domestic measures. Early species identification and specific management may help prevent serious sequelae of spider bites.
SPECIFIC ISOTYPE IMMUNE RESPONSE IN THE DIAGNOSIS OF HUMAN SCHISTOSOMIASIS PATHOLOGY?
Authors: BONNARD PHILIPPE , REMOUE FRANCK , SCHACHT ANNE-MARIE , DEUFFIC-BURBAN SYLVIE , DOMPNIER JEAN-PIERRE , ELGUERO ERIC , CHARRIER NICOLE , CASSAGNOU MICHEL , DIOP MAMADOU , LY ABDOULAYE , CAPRON ANDRE , RIVEAU GILLES
Published: September 2018

Since the few indirect markers available for assessing the development and the stage of intestinal schistosomiasis morbidity are weakly specific, endoscopy is still the only method able to detect severe forms of pathology. Therefore, we evaluated the isotype antibody response to the current schistosome antigen preparation (soluble egg antigens [SEA]) in 142 Senegalese patients infected with Schistosoma mansoni. They were stratified into three different stages of pathology according to ultrasonographic, endoscopic, and clinical parameters (stage 1 = no detectable pathology; stage 2 = moderate morbidity; stage 3 = severe forms of pathology). Only median specific IgG4, IgE, and IgA responses changed according to the stage of pathology. The IgA level was significantly higher in stages 2 and 3 compared with stage 1, and the IgE level was higher in stage 3 compared with stage 1. A high specific IgG4 level was observed only in stage 3 and was significantly different compared with stage 2. We show an association between the variability of the specific response to SEA and the degree of morbidity, and demonstrate that IgA and IgG4 responses could be combined markers to easily discriminate the different stages of pathology due to infection with S. mansoni.
MALARIA CONTROL AT THE DISTRICT LEVEL IN AFRICA: THE CASE OF THE MUHEZA DISTRICT IN NORTHEASTERN TANZANIA
Authors: ALILIO MARTIN S. , KITUA ANDREW , NJUNWA KATO , MEDINA MARTA , RØNN ANITA MANDRUP , MHINA JULIUS , MSUYA FIKIRINI , MAHUNDI JUDITH , DEPINAY JEAN MARC , WHYTE SUSAN , KRASNIK ALLAN , BYGBJERG IB CHRISTIAN
Published: September 2018

An assessment was done in Tanzania to determine the extent to which the primary health care services have contributed to reducing the burden of malaria since the system was initiated in the 1980s. Seven descriptive processes and outcome indicators of effectiveness were used: changes of malaria transmission and incidence over time; use of facility-based care services for malaria; patients’ access to professional advice; the trend of treatment failure over time of sulfadoxine-pyrimethamine and chloroquine; survival rates of severe cases at the district hospital; a district malaria control strategy; number of malaria specific training for care providers; and the number of activities carried out on mosquito control measures. The data were collected from 1996 to 2003 in the Muheza district northeastern Tanzania. It covered household interviews with a stratified sample of 1,250 respondents, and in-depth interviews with all 175 health care providers in the 35 health facilities within the district. All six members of the district health management team were also interviewed. Additional data came from dispensary and hospital records, and published literature. The results show an unchanged malaria disease burden. The average number of clinical malaria episodes per child less than five years of age remained between 3 and 3.5 episodes per year in the district since the 1960s. The comparison of cases expected in the population less than five years old with those seen in the district health facilities shows a coverage rate of 33%. Furthermore, between 1990 and 2003, little training on malaria was provided to health staff. The findings imply a limited effectiveness of district health services on malaria control, suggesting a weak process of translating national malaria goals to activities at the district level.
HUMAN LOIASIS IN A CAMEROONIAN VILLAGE: A DOUBLE-BLIND, PLACEBO-CONTROLLED, CROSSOVER CLINICAL TRIAL OF A THREE-DAY ALBENDAZOLE REGIMEN
Authors: TABI TABE-EBOB , BEFIDI-MENGUE ROSA , NUTMAN THOMAS B. , HORTON JOHN , FOLEFACK ALAIN , PENSIA EDITH , FUALEM RELLINDS , FOGAKO JOSEPHINE , GWANMESIA PHILOMENE , QUAKYI ISABELLA , LEKE ROSE
Published: September 2018

Because of the life-threatening, post-treatment reactions that have occurred in patients with loiasis treated with ivermectin, evaluation of a short-course albendazole regimen was undertaken in a Loa-endemic region of Cameroon. In a placebo-controlled, double-blinded, crossover study, 99 subjects with microfilaremia (100–3,3837/mL) were assigned to receive albendazole (400 mg; n = 48) or placebo (n = 51) for three days and were followed for 180 days; at day 180, the groups were crossed over and followed for an additional six months. In those initially receiving albendazole (ALB/PLAC), microfilarial levels decreased significantly by day 90 (P < 0.043), but returned to baseline by day 180. In those receiving albendazole at day 180 (PLAC/ALB), microfilarial levels also decreased following albendazole (P = 0.005). Blood eosinophil and antifilarial IgG levels did not change significantly for either group, although antifilarial IgG4 levels did in the ALB/PLAC group at day 180. Most subjects continued to have elevations in microfilaremia, suggesting that more intensive regimens of albendazole will be necessary to reduce Loa microfilaremia to levels safe enough to allow for ivermectin use.
CHILD COVERAGE WITH MOSQUITO NETS AND MALARIA TREATMENT FROM POPULATION-BASED SURVEYS IN AFRICAN COUNTRIES: A BASELINE FOR MONITORING PROGRESS IN ROLL BACK MALARIA
Authors: MONASCH ROELAND , REINISCH ANNETTE , STEKETEE RICHARD W. , KORENROMP ELINE L. , ALNWICK DAVID , BERGEVIN YVES
Published: September 2018

We assessed the proportion of febrile children less than five years old with prompt effective antimalarial treatment and the proportion of those less than five years old sleeping under insecticide-treated nets (ITNs) or any mosquito net the preceding night in African malarious countries. Data were reviewed from 23 Multiple Indicator Cluster Surveys and 13 Demographic and Health Surveys conducted between 1998 and 2002. A median of 53% of febrile children received antimalarial treatment. A median of 84% of these treatments, however, involved chloroquine, and the proportion of treatments given within two days of onset of symptoms was unknown in most surveys. Median coverages of those less than five years old with any net and ITNs were 15% and 2%, respectively. Use of nets, and especially ITNs, was consistently lower in rural than in urban areas. At the outset of intensified malaria control under Roll Back Malaria, coverage with principal interventions was far below the target of 60% set for Africa in 2005.
IMPACT OF SNAKE BITES AND DETERMINANTS OF FATAL OUTCOMES IN SOUTHEASTERN NEPAL
Authors: SHARMA SANJIB K. , CHAPPUIS FRANÇOIS , JHA NILHAMBAR , BOVIER PATRICK A. , LOUTAN LOUIS , KOIRALA SHEKHAR
Published: September 2018

Current available data on snake bites in Nepal are based solely on hospital statistics. This community-based study aimed at evaluating the impact of snake bites and determining the risk factors associated with a fatal outcome in southeastern Nepal. A total of 1,817 households, selected by a random proportionate sampling method, were visited by trained fieldworkers in five villages. Extensive data from snake bite victims during the 14 previous months were recorded and analyzed. One hundred forty-three snake bites including 75 bites with signs of envenoming were reported (annual incidence = 1,162/100,000 and 604/100,000, respectively), resulting in 20 deaths (annual mortality rate = 162/100,000). Characteristics of krait bites such as bites occurring inside the house, while resting, and between midnight and 6:00 am were all factors associated with an increased risk of death, as were an initial consultation with a traditional healer, a long delay before transport, and a lack of available transport. An initial transfer to a specialized treatment center and transport by motorcycle were strong protective factors. Among the 123 survivors, wounds required dressing and surgery in 30 (24%) and 10 (8%) victims, respectively, the mean working incapacity period was 15 days, and the mean out-of-pocket expense was 69 U.S. dollars. Snake bite is a major but neglected public health problem in southeastern Nepal. Public health interventions should focus on improving victims’ rapid access to anti-snake venom serum by promoting immediate and fast transport to adequate treatment centers, particularly for bites occurring at night.
ANTIGENIC AND GENETIC TYPING OF WHATAROA VIRUSES IN AUSTRALIA
Authors: SALEH SUHA M. , POIDINGER MICHAEL , MACKENZIE JOHN S. , BROOM ANNETTE K. , LINDSAY MICHAEL D. A. , RUSSELL RICHARD C. , CLOONAN MICHAEL J. , CALISHER CHARLES H. , BURGESS GRAHAM W. , HALL ROY A.
Published: September 2018

We recently characterized three novel alphaviruses isolated from mosquitoes captured in New South Wales, Australia. Initial cross-neutralization studies revealed antigenic similarity to the Sindbis virus (SINV)–like Whataroa virus (WHAV), heretofore found only in New Zealand. Nucleotide sequence analysis showed that the WHAV-like viruses shared >99% nucleotide sequence similarity with each other, and 96–97% similarity with prototype WHAV. Enzyme-linked immunosorbent assay reactions of a panel of monoclonal antibodies to SINV showed that the novel WHAV-like viruses displayed identical binding patterns and were antigenically distinct from all SINV isolates examined. Although these viruses displayed a similar binding pattern to prototype WHAV, three monoclonal antibodies discriminated them from the New Zealand virus. Our results suggest that these novel alphaviruses are antigenic variants of WHAV and represent the first reported isolations of this virus from outside New Zealand. The monoclonal antibodies used in this study will be useful for typing new SINV and SINV-like isolates.
IDENTIFICATION OF REPTILIAN AND AMPHIBIAN BLOOD MEALS FROM MOSQUITOES IN AN EASTERN EQUINE ENCEPHALOMYELITIS VIRUS FOCUS IN CENTRAL ALABAMA
Authors: CUPP EDDIE W. , ZHANG DUNHUA , YUE XIN , CUPP MARY S. , GUYER CRAIG , SPRENGER TONYA R. , UNNASCH THOMAS R.
Published: September 2018

Uranotaenia sapphirina, Culex erraticus, and Cx. peccator were collected in an enzootic eastern equine encephalomyelitis (EEE) virus focus in central Alabama (Tuskegee National Forest) from 2001 to 2003 and analyzed for virus as well as host selection. EEE virus was detected in each species every year except 2003, when pools of Cx. peccator were negative. Most (97%) of the 130 Cx. peccator blood meals identified were from ectothermic hosts; 3% were from birds. Among blood meals from reptiles (approximately 75% of the total), 81% were from Agkistrodon piscivorus (cottonmouth); all amphibian blood meals (approximately 25%) were from Rana spp. with > 50% taken from the bullfrog R. catesbeiana. Host identifications were made from 131 of 197 Cx. erraticus, but only 3 (2%) were derived from ectothermic species. Identification of Ur. sapphirina blood meals proved difficult and only 2 of 35 hosts were determined. Both were from R. catesbeiana. Ectothermic species are possible EEE virus reservoirs in the southeastern United States where species such as Cx. peccator and Ur. sapphirina occur with large, diverse reptilian, amphibian, and avian populations such as those at the Tuskegee site.
ANALYSIS OF CIRCUMSPOROZOITE PROTEIN–SPECIFIC IMMUNE RESPONSES FOLLOWING RECENT INFECTION WITH PLASMODIUM VIVAX
Authors: SUPHAVILAI CHAISUREE , LOOAREESUWAN SORNCHAI , GOOD MICHAEL F.
Published: September 2018

CD8+ and CD4+ T cells are involved in immunity to the pre-erythrocytic stage of malaria. This study has been undertaken to define T cell epitopes on the Plasmodium vivax circumsporozoite protein (CSP) and to analyze the early induction of immune response following infection. We identified CD4+ and CD8+ T epitopes recognized by different strains of mice as well as by humans. The CD4+ T cell response in mice was found to be similar in all strains, but variation between strains was evident. Five H-2d-restricted CD8+ cytotoxic T lymphocyte (CTL) epitopes, but no H-2k-or H-2b-restricted epitopes, could be defined. Non-H-2 genes were also able to regulate the response. In recently infected Thai adults, poor immunoresponsiveness was demonstrated. CTL activity and proliferative responses of T cells from malaria-exposed donors were very low. In contrast, exposed individuals had specific antibodies against the immunodominant repeats of both common strains of the P. vivax CSP; however, titers decreased following treatment.
SHORT REPORT: DURATION OF TICK ATTACHMENT REQUIRED FOR TRANSMISSION OF POWASSAN VIRUS BY DEER TICKS
Authors: EBEL GREGORY D. , KRAMER LAURA D.
Published: September 2018

Infected deer ticks (Ixodes scapularis) were allowed to attach to naive mice for variable lengths of time to determine the duration of tick attachment required for Powassan (POW) virus transmission to occur. Viral load in engorged larvae detaching from viremic mice and in resulting nymphs was also monitored. Ninety percent of larval ticks acquired POW virus from mice that had been intraperitoneally inoculated with 105 plaque-forming units (PFU). Engorged larvae contained approximately 10 PFU. Transstadial transmission efficiency was 22%, resulting in approximately 20% infection in nymphs that had fed as larvae on viremic mice. Titer increased approximately 100-fold during molting. Nymphal deer ticks efficiently transmitted POW virus to naive mice after as few as 15 minutes of attachment, suggesting that unlike Borrelia burgdorferi, Babesia microti, and Anaplasma phagocytophilum, no grace period exists between tick attachment and POW virus transmission.
EFFECT OF BLOCKING THE CXCL9/10-CXCR3 CHEMOKINE SYSTEM IN THE OUTCOME OF ENDOTHELIAL-TARGET RICKETTSIAL INFECTIONS
Authors: VALBUENA GUSTAVO , WALKER DAVID H.
Published: September 2018

Rickettsiae cause systemic infections such as Rocky Mountain spotted fever and boutonneuse fever. The main cellular target of these obligately intracellular bacteria is the endothelium. T lymphocytes are the most important effectors of immunity, and the CXCR3 ligands CXCL9 and CXCL10 may play an important role in the T cell-mediated clearance of rickettsiae from the infected vasculature as suggested by recent expression studies. Here we showed that antibody-mediated neutralization of CXCL9 and CXCL10, and CXCR3 gene knockout, had no effect on survival or bacterial loads of mice infected with rickettsiae. We also demonstrated that rickettsiae triggered the endothelial expression of intercellular adhesion molecule 1 and vascular cell adhesion molecule 1 in vivo. These findings suggested that antigenic presentation by endothelial cells together with an endothelial inflammatory phenotype induced by the rickettsial infection may be sufficient to arrest T cells and trigger their anti-rickettsial effector mechanisms without the need for chemokines.
PROTECTION OF C3HEB/FEJ MICE AGAINST LEISHMANIA AMAZONENSIS CHALLENGE AFTER PREVIOUS LEISHMANIA MAJOR INFECTION
Authors: VANLOUBBEECK YANNICK , JONES DOUGLAS E.
Published: September 2018

The Th1 response elicited in mice infected with Leishmania major has been used as a model to characterize cellular immune defects associated with L. amazonensis infection. However, it is not known if the immune response associated with the infection by virulent L. major parasites can promote resistance to a subsequent L. amazonensis infection. Our data demonstrate that C3HeB/FeJ mice infected subcutaneously with virulent L. major are resistant to an L. amazonensis challenge. The healing phenotype is characterized by a Th1 response as measured by increased production of interferon-γ and low levels of interleukin-4 in the draining lymph node. Together, this indicates that the Th1 response associated with L. major infection can promote resistance to L. amazonensis infection and that it can be used as a tool to study the immune defects associated with L. amazonensis infection.
SHORT REPORT: THE USE OF A POLYMERASE CHAIN REACTION TO DETECT ECHINOCOCCUS GRANULOSUS (G1 STRAIN) EGGS IN SOIL SAMPLES
Authors: SHAIKENOV B. S. , RYSMUKHAMBETOVA A. T. , MASSENOV B. , DEPLAZES P. , MATHIS A. , TORGERSON P. R.
Published: September 2018

Cystic echinococcosis is a re-emerging disease in central Asia. A total of 120 soil samples taken from 30 gardens of rural homesteads in southern Kazakhstan were analyzed for the presence of taeniid eggs using a concentration technique. Of these, 21 (17.5%) were shown to be contaminated with taeniid eggs. These isolated taeniid eggs were further analyzed using a polymerase chain reaction specific for the G1 (sheep) strain of the tapeworm Echinococcus granulosus, and five samples were shown to be positive. This study demonstrates the widespread contamination of the environment with E. granulosus eggs in an Echinococcus-endemic area and thus the potential for indirect transmission of E. granulosus to humans from such sources.
COMPARISON OF DENGUE-1 VIRUS ENVELOPE GLYCOPROTEIN GENE SEQUENCES FROM FRENCH POLYNESIA
Authors: LAILLE MANOLA , ROCHE CLAUDINE
Published: September 2018

Dengue (DEN) is the leading arboviral infection of humans, with 100 million cases annually in the tropical areas of the world. The recent severe DEN-1 epidemic in French Polynesia in 2001, with an incidence rate of 16% and more than 45% of the cases with dengue hemorrhagic fever/dengue shock syndrome among 1,400 hospitalized children and eight fatalities, led us to study this new circulating strain. The entire envelope (E) gene of two French Polynesian DEN-1 virus isolates from the two epidemics of 1988–1989 (FP89) and 2001 (FP01) were sequenced and compared with 29 published DEN-1 virus E gene sequences. Phylogenetic relationships showed that the FP89 strain belonged to genotype V and the FP01 strain to genotype IV based on studies on the same region of DEN-1 virus genome (1,485 nucleotides). The recent dengue epidemic in French Polynesia in 2001 was probably due to the introduction of a new DEN-1 virus from Southeast Asia, since the minimum nucleotide divergence was 3.3% with A88, the Indonesian strain isolated in 1988 in Jakarta.
GENETIC AND PHENOTYPIC VARIATION OF WEST NILE VIRUS IN NEW YORK, 2000–2003
Authors: EBEL GREGORY D. , CARRICABURU JUSTIN , YOUNG DAVID , BERNARD KRISTEN A. , KRAMER LAURA D.
Published: September 2018

West Nile virus (WNV) strains circulating during the first five years of WNV transmission in New York were collected, partial nucleotide sequences were determined, and in vitro and in vivo phenotypic analyses of selected strains were undertaken to determine whether observed increases in the intensity of enzootic and epidemic transmission in New York State during 2002 and 2003 were associated with viral genetic changes. Functionally diverse regions of the WNV genome were also compared to determine whether some regions may be more or less variable than others. The complete envelope coding regions of 67 strains and fragments of the nonstructural protein 5 (NS5) and 3′ noncoding regions of 39 strains collected during 2002 and 2003 were examined. West Nile virus in New York remains relatively genetically homogeneous. Viral genetic diversity was greater in 2002 and 2003 at both the nucleotide and amino acid levels than in previous years due to the emergence of a new WNV genotype in 2002. This genotype persisted and became dominant in 2003. Envelope and NS5 coding regions were approximately two-fold more likely than the 3′ untranslated region to contain nucleotide substitutions, and the envelope region was approximately three-fold more likely to contain amino acid substitutions than the NS5 region. Variation was noted in in vivo mosquito transmission assays, but not in in vitro growth studies. Strains belonging to the epizootiologically dominant clade were transmitted after approximately two fewer days of extrinsic incubation, providing a possible mechanism for the dominance of this clade. The observed increase in the intensity of WNV transmission beginning in 2002 was associated with an increase in viral genetic diversity that was the result of the emergence of an additional phylogenetic clade. This genotype seems to possess an advantage over previously recognized WNV strains in mosquito transmission phenotype.
POPULATION DYNAMICS OF AEDES AEGYPTI FROM A DENGUE HYPERENDEMIC URBAN SETTING IN COLOMBIA
Authors: OCAMPO CLARA B. , WESSON DAWN M.
Published: September 2018

This study evaluated if the Aedes aegypti population in the city of Cali, Colombia was composed of genetically distinct local populations with different levels of insecticide resistance and dengue vector competence. Insecticide resistance was assayed biochemically and was associated with varying levels of mixed-function oxidases and non-specific esterases. The genes encoding those enzymes were under selective pressure from insecticides used to suppress Ae. aegypti populations. Vector competence showed heterogeneity among the vector populations ranging from 19% to 60%. Population genetic analysis of random amplified polymorphic DNA-polymerase chain reaction products, expressed as genetic distance, Wright’s Fst, and migration rate (Nm), demonstrated moderate genetic differentiation among Ae. aegypti from four sites (Fst = 0.085). The results from all characteristics evaluated in the study demonstrated spatial and temporal variation between Ae. aegypti populations. At any specific time, the local populations of Ae. aegypti were genetically differentiated and unique with respect to insecticide resistance and vector competence. Both characteristics changed independently.
MOLECULAR DIFFERENTIATION OF COLONIZED HUMAN MALARIA VECTORS BY 28S RIBOSOMAL DNA POLYMORPHISMS
Authors: KENT REBEKAH J. , WEST AIMEE J. , NORRIS DOUGLAS E.
Published: September 2018

Anopheles gambiae s.s. Giles, An. stephensi Liston, An. freeborni Aitken, and An. quadrimaculatus Say are cultured and studied in molecular genetic and transgenic laboratories with increasing frequency. With limited research space, these mosquitoes are often maintained in the same insectary. Under these conditions, cross-contamination of colonies can occur and have devastating consequences to affected research programs. We have developed a polymerase chain reaction-based assay targeting the 28S large subunit ribosomal RNA gene to easily differentiate between these four taxa and An. funestus Giles, which occurs in sympatry with An. gambiae. The resulting assay identifies individual mosquito preparations as well as all taxa within a mixed or pooled DNA template preparation.
BIONOMICS AND SYSTEMATICS OF THE ORIENTAL ANOPHELES SUNDAICUS COMPLEX IN RELATION TO MALARIA TRANSMISSION AND VECTOR CONTROL
Authors: DUSFOUR ISABELLE , HARBACH RALPH E. , MANGUIN SYLVIE
Published: September 2018

The taxonomic history, distribution, bionomics, systematics, and vector control strategies for the Anopheles sundaicus complex are reviewed in relation to malaria epidemiology. The lack of data on the bionomics, insecticide resistance, and vector capacity, as well as the general lack of surveillance and monitoring of potential vector populations, make the development of targeted control measures problematic. It will be necessary to elucidate, characterize and identify all members of the complex to determine their distributions, disease relationships, ecologic relationships, and resistance to insecticides. This knowledge is essential for epidemiologic studies, the design and implementation of appropriate vector control measures, and the development of strategies for monitoring and assessing the potential risk of malaria outbreaks due to members of the complex.
AN IN VITRO LARVAL MOTILITY ASSAY TO DETERMINE ANTHELMINTIC SENSITIVITY FOR HUMAN HOOKWORM AND STRONGYLOIDES SPECIES
Authors: KOTZE A. C. , CLIFFORD S. , O’GRADY J. , BEHNKE J. M. , McCARTHY J. S.
Published: September 2018

With the implementation of programs to control lymphatic filariasis and soil-transmitted helminths using broad spectrum anthelmintics, including albendazole and ivermectin, there is a need to develop an in vitro assay for detection of drug resistance. This report describes an in vitro assay for measuring the effects of ivermectin and benzimidazoles on the motility of larvae of the hookworm species Ancylostoma ceylanicum, A. caninum, and Necator americanus, and Strongyloides species including Strongyloides stercoralis, and S. ratti. A dose-response relationship was demonstrated with each of the parasite species, with distinct differences observed between the various species. In pilot field testing of the assay with N. americanus larvae recovered from human fecal samples, a dose-response relationship was observed with ivermectin. While the assay has demonstrated the ability to determine drug responsiveness, its usefulness in resistance detection will require correlation with the clinical outcome among individuals infected with parasite strains showing different drug sensitivities.
HOUSEHOLD SURVEY OF DENGUE INFECTION IN CENTRAL BRAZIL: SPATIAL POINT PATTERN ANALYSIS AND RISK FACTORS ASSESSMENT
Authors: SIQUEIRA JOÃO B. , MARTELLI CELINA M. T. , MACIEL IVAN J. , OLIVEIRA RENATO M. , RIBEIRO MARIA G. , AMORIM FLÚVIA P. , MOREIRA BRUNO C. , CARDOSO DIVINA D. P. , SOUZA WAYNER V. , ANDRADE ANA LÚCIA S. S.
Published: September 2018

Urban dengue fever is now considered a major public health threat in most American countries. A household survey was conducted in the city of Goiânia in central Brazil in 2001 to assess prevalence of dengue infection and individual and area-based risk factors. Spatial point pattern analysis was performed using the dual Kernel method. A total of 1,610 households were surveyed; 1,585 individuals more than five years old had blood and data collected. Sera were tested for IgM/IgG antibodies by an enzyme-linked immunoassay. Area-based indicators derived from census data were linked to geocoded residential address. The seroprevalence of dengue was 29.5% and the estimate prevalence surface reached 50% in the outskirts areas. The risk of infection was significantly associated with older age (P < 0.01), low education (odds ratio [OR] = 3.45, 95% confidence interval [CI] = 1.82–6.55), and low income (OR = 1.32, 95% CI = 1.02–1.71) in multivariate analysis. This study highlighted the heterogeneity of dengue transmission within the city and can assist in spatial targeting control interventions.
RISK FACTORS FOR PLASMODIUM VIVAX GAMETOCYTE CARRIAGE IN THAILAND
Authors: NACHER MATHIEU , SILACHAMROON UDOMSAK , SINGHASIVANON PRATAP , WILAIRATANA POLRAT , PHUMRATANAPRAPIN WEERAPONG , FONTANET ARNAUD , LOOAREESUWAN SORNCHAI
Published: September 2018

To study the risk factors for Plasmodium vivax gametocyte carriage, the presence or absence of gametocytes was determined in 2,125 patients with P. vivax malaria participating in clinical trials at the Hospital for Tropical Diseases in Bangkok, Thailand. Stepwise logistic regression models were used to determine which variables were significantly related to gametocyte carriage. On admission, 615 patients (29%) had detectable gametocytes (before treatment). After treatment had started, an additional 245 patients (11%) developed patent gametocytemia. The variables retained by multivariate analysis were highest observed temperature (adjusted odds ratio [AOR] per °C increase = 0.82, 95% confidence interval [CI] = 0.71–0.94, P = 0.006), asexual parasitemia > 9,200/μL (AOR = 2.8, 95% CI = 1.9–4.2, P < 0.0001), erythrocyte counts (AOR = 0.8/million/μL increase, 95% CI = 0.67–0.95, P = 0.01), monocyte percentage (AOR = 0.93 per % increase, 95% CI = 0.89–0.96, P < 0.0001), lymphocyte percentage (AOR = 0.98 per % increase, 95% CI = 0.97–0.99, P = 0.006), albumin (AOR = 0.67 per 10 g/mL increase, 95% CI = 0.5–0.9, P = 0.007), and anion gap (AOR = 1.1 per unit increase, 95% CI = 1.02–1.14, P = 0.009). The possible significance of these observations is discussed.
INFLUENCE OF BREEDING SITES FEATURES ON GENETIC DIFFERENTIATION OF AEDES AEGYPTI POPULATIONS ANALYZED ON A LOCAL SCALE IN PHNOM PENH MUNICIPALITY OF CAMBODIA
Authors: PAUPY CHRISTOPHE , CHANTHA NGAN , HUBER KARINE , LECOZ NICOLAS , REYNES JEAN-MARC , RODHAIN FRANCOIS , FAILLOUX ANNA-BELLA
Published: September 2018

This study analyzed genetic differentiation of 20 Aedes aegypti populations collected along a street in Phnom Penh Municipality of Cambodia. Using allozyme and microsatellite variations, we demonstrated that populations were differentiated and the pattern of differentiation was dependent on the type of breeding sites. Moreover, insecticide treatments with temephos mostly affect the population functioning of discarded containers. Low gene flow detected could limit the natural diffusion of resistant populations that might instead take advantage of human displacements to spread.
A PRESUMPTIVE CASE OF TOXOCARIASIS ASSOCIATED WITH EOSINOPHILIC PLEURAL EFFUSION: CASE REPORT AND LITERATURE REVIEW
Authors: ASHWATH MAHI LAKSHMI , ROBINSON DONALD R. , KATNER HAROLD P.
Published: September 2018

Human toxocariasis is a helminthozoonosis caused by Toxocara sp. Larval migration of the organism through the tissues can result in eosinophila associated with a broad spectrum of clinical manifestations. We report a case of eosinophilic pleural effusion and CD8 cell deficiency associated with Toxocara sp. The symptoms of this patient responded promptly to a nonsteroidal anti-inflammatory medication (naproxen). This is only the fourth reported case of a pleural effusion associated with Toxocara.
RELATIONSHIPS BETWEEN THE OUTCOME OF PLASMODIUM FALCIPARUM INFECTION AND THE INTENSITY OF TRANSMISSION IN AFRICA
Authors: SMITH T. , KILLEEN G. , LENGELER C. , TANNER M.
Published: September 2018

Establishing the relationship between transmission intensity and health outcomes is crucial for the planning of long-term malaria control programs. Unfortunately this is fraught with methodologic difficulties. In this report, we address some of these problems by considering some important parameters that have previously been ignored. One important consideration is that the incidence of infection for Plasmodium falciparum malaria is much lower than entomologic inoculation rates (EIRs), especially at higher transmission levels. Moreover, biting rates of malaria vectors per host depend on his or her biomass and thus age. We propose an algorithm for estimating human infection rates from the EIR with allowance for these two factors. We then re-analyzed 1) data on EIR and age-specific incidence of clinical malaria in two villages in Senegal and 2) a survey of infant and child mortality rates across Africa. In each case, we review analyses of incidence in relation to the EIR and carry out a new analysis of morbidity and mortality rates in relation to the estimated incidence of infection (h). Reduction in malaria transmission may result in a shift of acute malaria attacks to older ages, and thus have little impact on life-time risk of clinical attacks. However, our analysis of the Senegalese data indicates that the peak incidence rate of disease relative to infection rates is in the youngest age groups in both the villages of Dielmo (EIR = 200 infectious bites per year) and Ndiop (EIR = 20). This suggests that simple models of acquired clinical immunity can explain age-incidence profiles better when incidence is expressed in relation to h, than when expressed in relation to the EIR. Relationships of malaria transmission intensity (in endemic areas) with overall mortality are very different from those with acute morbidity. Infant mortality rates (IMRs) decrease substantially when the EIR is reduced, probably largely because of prevention of indirect mortality. However, we were are not yet able to draw strong conclusions about the shape of relationships between the IMR and h because many of the available data points have similar values of h. The effects of transmission reduction on mortality rates in older age groups are also uncertain. However, it is clear that reduction of exposure during infancy is not reflected in increased mortality at older ages.
SPATIO-TEMPORAL ANALYSIS OF REINFESTATION BY TRIATOMA INFESTANS (HEMIPTERA: REDUVIIDAE) FOLLOWING INSECTICIDE SPRAYING IN A RURAL COMMUNITY IN NORTHWESTERN ARGENTINA
Authors: CECERE MARÍA C. , VAZQUEZ-PROKOPEC GONZALO M. , GÜRTLER RICARDO E. , KITRON URIEL
Published: September 2018

The spatio-temporal reinfestation patterns by Triatoma infestans following a blanket insecticide spraying in the rural community of Amamá in northwestern Argentina were analyzed using a geographic information system, satellite imagery, and spatial statistics. Domestic and peridomestic reinfestation by triatomine bugs was monitored from 1993 to 1997. Triatoma infestans was detected at least once in 75% of 2,110 sites evaluated. The prevalence of sites positive at least once for T. infestans during the study period increased sharply from 1993–1995 (0.6–2.9%) to November 1997 (32%). The initial source of T. infestans was a pig corral in southern Amamá one year post-spraying. Subsequent infestations were clustered around this initial focus at a distance of approximately 400 meters starting in 1995. In 1996, clustering was maximized in sites within the same or in neighboring compounds at distances of 25–175 meters. An effective control program on the community level will be based on the spraying of actual epicenters and sites within 450 meters of these epicenters to prevent the propagation of T. infestans.
A CHOLERA EPIDEMIC AMONG THE NICOBARESE TRIBE OF NANCOWRY, ANDAMAN, AND NICOBAR, INDIA
Authors: SUGUNAN ATTAYOOR P. , GHOSH ASIT R. , ROY SUBARNA , GUPTE MOHAN D. , SEHGAL SUBHASH C.
Published: September 2018

Cholera has not been reported from the Andaman and Nicobar Islands in India. In October 2002, an outbreak of diarrhea occurred among the Nicobarese tribe of the Nancowry group of islands. The outbreak affected 16 of the 45 inhabited villages of three islands with an attack rate of 12.8% and a case fatality ratio of 1.3%. Vibrio cholerae O1 El Tor was isolated from 18 of the 67 patients tested. A study conducted in one of the villages indicated that the outbreak was started there by a person who traveled to a nearby village where an outbreak was occurring. No specific water source could be identified as the source of infection because persons consuming water from all wells were affected. Water samples from 55 sources were tested and 38 of them were contaminated with Escherichia coli. The possible sources of V. cholerae are effluents from ships or poachers from neighboring countries where cholera is endemic.
A RECOMBINANT CYSTEINE PROTEINASE FROM LEISHMANIA (LEISHMANIA) CHAGASI SUITABLE FOR SERODIAGNOSIS OF AMERICAN VISCERAL LEISHMANIASIS
Authors: DE SOUZA DIAS SUZANA , DA COSTA PINHEIRO PAULO HENRIQUE , KATZ SIMONE , SANTOS MÁRCIA REGINA MACHADO DOS , BARBIÉRI CLARA LÚCIA
Published: September 2018

A recombinant protein, rLdccys1, which was produced by expression of the gene encoding a 30 kDa cysteine proteinase from Leishmania (Leishmania) chagasi, was used for detection of antibodies in sera from patients with active visceral leishmaniasis (VL) in enzyme-linked immunosorbent assays. Analysis of the predicted amino acid sequence of rLdccys1 showed that it contains all the characteristics of a cysteine proteinase. The ability of the protein to react with sera from humans with VL was also shown by Western blotting. The sensitivity for detection of specific antibodies to L. (L.) chagasi bodies using rLdccys1, L. (L.) chagasi promastigote lysates, and amastigote lysates was 80%, 98%, and 99%, respectively. No cross-reactivity between rLdccys1 and Chagas disease was observed, and there was little positive reactivity with sera from patients with cutaneous leishmaniasis and tuberculosis, compared with promastigote and amastigote extracts. Our findings indicate that rLdccys1 from L. (L.) chagasi constitutes a potential tool for the diagnosis of American VL.
COMPARISON OF MEGLUMINE ANTIMONIATE AND PENTAMIDINE FOR PERUVIAN CUTANEOUS LEISHMANIASIS
Authors: ANDERSEN ELLEN M. , CRUZ-SALDARRIAGA MARIA , LLANOS-CUENTAS ALEJANDRO , LUZ-CJUNO MARIA , ECHEVARRIA JUAN , MIRANDA-VERASTEGUI CESAR , COLINA OLGA , BERMAN JONATHAN D.
Published: September 2018

Pentamidine was compared with meglumine antimoniate (Glucantime) for 80 patients with cutaneous leishmaniasis due to Leishmania braziliensis in Peru. Of the 40 patients administered Glucantime (20 mg of antimony [Sb]/kg/day intravenously for 20 days), 31 cured (78%), 6 failed (15%), of which 5 were due to relapse, and 3 were lost to follow-up (7%). Of the 40 patients administered pentamidine (2 mg/kg every other day for seven injections), 14 were cured (35%), 23 failed (58%), and 3 were lost to follow-up (7%). Five pentamidine failures were due to relapse, and 14 failures were due to the presence of parasites two weeks after therapy. Both regimens were well tolerated. Gastrointestinal, musculoskeletal, and total adverse events were not statistically different in either group. Elevations in levels of liver enzymes and pancreatic enzymes were statistically higher in the Glucantime group, but no patient terminated therapy prematurely. In this study, Glucantime was more effective than pentamidine for treatment of L. braziliensis cutaneous leishmaniasis in Peru based on parasitologic as well as clinical criteria.
THE USE OF THE MULTI-ORGAN-DYSFUNCTION SCORE TO DISCRIMINATE DIFFERENT LEVELS OF SEVERITY IN SEVERE AND COMPLICATED PLASMODIUM FALCIPARUM MALARIA
Authors: HELBOK R. , DENT W. , NACHER M. , LACKNER P. , TREEPRASERTSUK S. , KRUDSOOD S. , WILAIRATANA P. , SILACHAMROON U. , LOOAREESUWAN S. , SCHMUTZHARD E.
Published: September 2018

Clinical presentation of Plasmodium falciparum malaria reflects a continuum from asymptomatic to multi-organ manifestation and death. Severe malaria is defined by the World Health Organization as a qualitative variable. We used the multi-organ dysfunction score (MODS) as a quantitative approach for severity in 29 patients with severe and complicated P. falciparum malaria to test its usefulness in discriminating different severity levels. The MODS on admission was highly correlated with the duration of symptoms after admission (r = 0.73, P < 0.001) and the serum level of tumor necrosis factor alpha (r = 0.41, P = 0.03). In addition, the simplified MODS, based mainly on clinical findings, was also correlated with liver and renal dysfunction during hospitalization (alanine transaminase, r = 0.42, P = 0.02; blood urea nitrogen, r = 0.45, P = 0.015). A score ≥ 16 was associated with significantly longer disease duration (P = 0.018). Thus, this score might provide a predictive value for morbidity in P. falciparum malaria.