bluuebunny/crossref_metadata_2025 huggingface dataset:
POPULATION GENETIC STRUCTURE OF THE AFRICAN MALARIA MOSQUITO ANOPHELES FUNESTUS IN KENYA
Authors: BRAGINETS OLGA P. , MINAKAWA NOBORU , MBOGO CHARLES M. , YAN GUIYUN
Published: September 2018

Anopheles funestus Giles is a major malaria vector in Africa, but little is known about the genetic structure of natural populations. In this study, microsatellite markers were used to investigate the genetic structure of A. funestus populations from Kenya. Two populations from western Kenya 80 km apart and two from coastal Kenya 50 km apart were collected and examined for allelic variation at five trinucleotide microsatellite loci. We found A. funestus Giles was the predominant species (>98%) in the A. funestus group in these populations. The western Kenya populations exhibited higher genetic diversity than the coastal populations. No significant genetic structure for populations within the coastal or western Kenya regions was detected. However, population genetic differentiation between the two regions was high (FST = 0.208, RST = 0.158), approximately two-fold higher than A. gambiae populations from the same area. The results suggest that the minimum area associated with a deme of A. funestus in western or coastal Kenya is larger than 50 km in diameter. The Great Rift Valley in east Africa, high-elevation mountains in western Kenya, and the vast arid area east to the Great Rift Valley may all play a role in restricting A. funestus gene flow between coastal and western Kenya.
GEOGRAPHIC DISTRIBUTION OF SCHISTOSOMIASIS AND SOIL-TRANSMITTED HELMINTHS IN WESTERN KENYA: IMPLICATIONS FOR ANTHELMINTHIC MASS TREATMENT
Authors: HANDZEL THOMAS , KARANJA DIANA M. S. , ADDISS DAVID G. , HIGHTOWER ALLEN W. , ROSEN DANIEL H. , COLLEY DANIEL G. , ANDOVE JULIUS , SLUTSKER LAURENCE , SECOR W. EVAN
Published: September 2018

A survey of 1,246 children 10–12 years old in 32 primary schools in Kenya near Lake Victoria was conducted to determine prevalence and distribution of schistosome and geohelminth infections. Stool and urine samples were collected and examined for eggs of Schistosoma mansoni, S. haematobium, and intestinal helminths. A questionnaire was used to obtain demographic information and to quantify exposure to surface waters. Houses, schools, and water sources were mapped using a geographic information system. The mean school prevalence of S. mansoni infection was 16.3% (range = 0–80%). Proximity to the lake (r = 0.89, P < 0.001) and contact with lake water were associated with infection, as were specific water-related activities including swimming, fishing, and collecting water. Sixty-three percent of students were infected with one or more other geohelminths and these infections were more homogenously distributed. The separate distributions of schistosome and geohelminth infections have important implications for combined mass-treatment programs.
AN ULTRASTRUCTURAL STUDY OF THE BRAIN IN FATAL PLASMODIUM FALCIPARUM MALARIA
Authors: PONGPONRATN EMSRI , TURNER GARETH D. H. , DAY NICHOLAS P. J. , PHU NGUYEN HOAN , SIMPSON JULIE A. , STEPNIEWSKA KASIA , MAI NGUYEN THI HOAN , VIRIYAVEJAKUL PARNPEN , LOOAREESUWAN SORNCHAI , HIEN TRAN TINH , FERGUSON DAVID J. P. , WHITE NICHOLAS J.
Published: September 2018

Cerebral malaria (CM) is a major cause of death in severe Plasmodium falciparum malaria. We present quantitative electron microscopic findings of the neuropathologic features in a prospective clinicopathologic study of 65 patients who died of severe malaria in Thailand and Vietnam. Sequestration of parasitized red blood cells (PRBCs) in cerebral microvessels was significantly higher in the brains of patients with CM compared with those with non-cerebral malaria (NCM) in all parts of the brain (cerebrum, cerebellum, and medulla oblongata). There was a hierarchy of sequestration with more in the cerebrum and cerebellum than the brain stem. When cerebral sequestration was compared with the peripheral parasitemia pre mortem, there were 26.6 times more PRBCs in the brain microvasculature than in the peripheral blood. The sequestration index was significantly higher in CM patients (median = 50.7) than in NCM patients (median = 6.9) (P = 0.042). The degree of sequestration of P. falciparum-infected erythrocytes in cerebral microvessels is quantitatively associated with pre-mortem coma.
PERIDOMESTIC RISK FACTORS FOR CANINE LEISHMANIASIS IN URBAN DWELLINGS: NEW FINDINGS FROM A PROSPECTIVE STUDY IN BRAZIL
Authors: MOREIRA EDSON D. , DE SOUZA VERENA M. M. , SREENIVASAN MEERA , LOPES NILSON L. , BARRETO RONALD B. , DE CARVALHO LAIN P.
Published: September 2018

Despite the wealth of information on the prevalence and correlates of canine Leishmania infection (CLI), data on its incidence are still sparse, and little is known regarding risk factors for CLI. We studied a cohort of dogs in an urban area in Brazil to determine whether incidence varied with age, breed, and environmental characteristics. The mean follow-up was 1.5 years, and the crude incidence rate was 11.8 cases/100 dog-years (95% confidence interval [CI] = 8.6–15.6). In the multivariate analysis, short fur was the strongest predictor of CLI (relative risk [RR] = 9.4). In addition, our data indicate that raising pigs (RR = 4.1), chickens (RR = 3.3), or other livestock (RR = 2.6) significantly increased the risk of CLI. Thus, suggesting control measures directed towards modifying the environmental factors favoring contact between vectors, reservoirs, and susceptible humans, such as proximity to pigpens or hen houses. Furthermore, conventional control programs of insecticidal spraying of human dwellings should also apply insecticide in and around animal sheds.
STORAGE DURATION AND POLYMERASE CHAIN REACTION DETECTION OF PLASMODIUM FALCIPARUM FROM BLOOD SPOTS ON FILTER PAPER
Authors: CHAORATTANAKAWEE S. , NATALANG O. , HANANANTACHAI H. , NACHER M. , BROCKMAN A. , KRUDSOOD S. , LOOAREESUWAN S. , PATARAPOTIKUL J.
Published: September 2018

To evaluate the effect of long-term storage of sample filters on the sensitivity of polymerase chain reaction (PCR) detection of malaria, 252 blood spots from patients with microscopically confirmed Plasmodium falciparum malaria were analyzed and stratified by storage duration. The spots were collected between 1996 and 2000 on filter paper and stored at room temperature. A Chelex-based method was used to extract the DNA. Unexpectedly, after the first purification, the sensitivity of the PCR from recently stored samples was low and showed progressively increased with time storage (P = 0.003, by chi-square test for linear trend). This suggested that PCR inhibitors were easier to dissolve from the more recent blood spots (< 4 years old) than from blood spots ≥4 years old, thus leading to a time-dependent increase in PCR sensitivity. However, if DNA was purified again (when the first PCR result was negative), the cumulative sensitivity was not influenced by storage duration. This indicated that length of storage is not a critical issue providing purification is sufficient.
HYPERENDEMIC FASCIOLIASIS ASSOCIATED WITH SCHISTOSOMIASIS IN VILLAGES IN THE NILE DELTA OF EGYPT
Authors: ESTEBAN JOSE-GUILLERMO , GONZALEZ CAROLINA , CURTALE FILIPPO , MUÑOZ-ANTOLI CARLA , VALERO MARIA ADELA , BARGUES MARIA DOLORES , EL SAYED MABROUK , EL WAKEEL ALY A. W. , ABDEL-WAHAB YEHIA , MONTRESOR ANTONIO , ENGELS DIRK , SAVIOLI LORENZO , MAS-COMA SANTIAGO
Published: September 2018

Coprologic surveys were carried out in villages of the Behera Governorate in the Nile Delta region of Egypt to characterize the epidemiologic features of human fascioliasis caused by Fasciola hepatica and F. gigantica in this lowland endemic area by comparison with fascioliasis caused by only F. hepatica in areas hyperendemic for human disease in the Andean highlands of South America. The fascioliasis prevalences detected (range = 5.2–19.0%, mean = 12.8%) are the highest obtained in Egypt. The comparison with previous results suggests that in the Nile Delta, fascioliasis is spreading from an original situation of sporadic human cases in well-known endemic foci for animal disease to an endemic distribution in humans, which may be characterized as a mesoendemic region that includes several hyperendemic areas for human disease. As in Andean countries, a relationship with sex was found, although in Egypt prevalences, but not intensities, appeared to be significantly higher in females. All ages appear to be susceptible to liver fluke infection, with prevalences and intensities being lower before and after school age, a situation that is consistent with that detected in Andean countries, although the peak in the 9–11-year-old age group appears less pronounced in Egypt. The intensities were very high when compared with those found in subjects sporadically infected in areas endemic for animal disease, but relatively low for a hyperendemic situation, although the intensities may not be conclusive because of the transmission seasonality of fascioliasis in the Nile Delta. The marked similarities in the qualitative and quantitative spectrums of protozoans and helminths, multiparasitisms, and associations between liver flukes and other parasitic species suggest physiographic-hydrographic and behavioral-social characteristics similar in all areas hyperendemic for human fascioliasis, which are independent of other factors such as climate, altitude, and cultural or religious features. The significant positive association between liver fluke infection and schistosomiasis mansoni detected in one locality has never been described elsewhere, and must be considered relevant from clinical, pathologic, diagnostic, and therapeutic points of view. Interestingly, the relationships of schistosomiasis prevalences and intensities with sex and age follow patterns similar to those found in fascioliasis.
PREVALENCE OF ANTIBODIES TO UNIQUE TAENIA SOLIUM ONCOSPHERE ANTIGENS IN TAENIASIS AND HUMAN AND PORCINE CYSTICERCOSIS
Authors: VERASTEGUI MANUELA , GILMAN ROBERT H. , GARCIA HECTOR H. , GONZALEZ ARMANDO E. , ARANA YANINA , JERI CESAR , TUERO ISKRA , GAVIDIA CESAR M. , LEVINE MIN , TSANG VICTOR C. W. , _ _
Published: September 2018

The presence of two oncosphere antigens (OAs) of 22.5 and 31.3 kD in whole and excretory/secretory (ES) OA preparations of both Taenia solium and T. saginata or in antigen preparations from T. solium metacestodes or immature tapeworms was assessed. This included an evaluation of whether antibodies to other cestodes cross-reacted to these OAs. The OAs were present in whole oncosphere extract and E/S antigens of T. solium, but were not present in other stages (immature tapeworm or metacestode) or in OAs of T. saginata. The majority (95%) of T. solium tapeworm carriers had antibodies to these OAs, while only 20% of active neurocysticercosis cases were positive. No antibodies to the OAs were found in healthy controls, subjects infected with Hymenolepis nana, patients with hydatid disease, T. saginata tapeworm carriers, hamsters infected with immature T. solium tapeworms, or dogs infected with Echinococcus granulosus. The OAs are stage and species specific to T. solium and antibodies to OAs are usually present in tapeworm carriers.
SHORT REPORT: IDENTIFICATION OF ECHINOCOCCUS SPECIES FROM A YAK IN THE QINGHAI-TIBET PLATEAU REGION OF CHINA
Authors: XIAO NING , QIU JIAMIN , NAKAO MINORU , NAKAYA KAZUHIRO , YAMASAKI HIROSHI , SAKO YASUHITO , MAMUTI WULAMU , SCHANTZ PETER M. , CRAIG PHILIP S. , ITO AKIRA
Published: September 2018

The species identification of an echinococcal lesion in the liver of a yak in the Qinghai-Tibet plateau region of China, where both Echinococcus granulosus and E. multilocularis are present, was difficult to determine because of the atypical appearance of the lesion. Polymerase chain reaction–based mitochondrial genotyping allowed us to discriminate the Echinococcus species. Nucleotide sequences of the cytochrome c oxidase subunit 1 (cox1) and cytochrome b (cytb) genes amplified from the echinococcal lesion demonstrated that the yak was infected with the E. granulosus G1 genotype (sheep strain).
ENDEMIC MALARIA IN THE PERUVIAN AMAZON REGION OF IQUITOS
Authors: ROSHANRAVAN BABACK , KARI ELINA , GILMAN ROBERT H. , CABRERA LILIA , LEE ELLEN , METCALFE JOHN , CALDERON MARITZA , LESCANO ANDRES G. , MONTENEGRO SONIA H. , CALAMPA CARLOS , VINETZ JOSEPH M.
Published: September 2018

A cross-sectional study was conducted in the Peruvian Amazon to test the hypothesis that a reservoir of asymptomatic malaria parasitemic patients would form the basis for continuing malaria endemicity in the region. Active surveillance yielded a Plasmodium spp. slide-positive prevalence of 4.2% (43 of 1,023) and a polymerase chain reaction (PCR)–positive prevalence of 17.6% (144 of 819). Plasmodium vivax prevalence was 2.9% and 14.2% while Plasmodium falciparum prevalence was 1.3% and 2.6% by microscopy and PCR, respectively. Approximately two-thirds of slide-positive and one-fourth of PCR-positive people were symptomatic. Anemia was associated with slide positivity (P < 0.001) and PCR positivity for P. falciparum (P = 0.003). Sensitivity of field microscopy and agreement between field and reference laboratory microscopists were low, arguing for using PCR for epidemiologic investigation and malaria control. While these data confirm recent findings from the Brazilian Amazon suggesting that sufficient numbers of asymptomatic malaria parasitemic patients are present to form a persistent reservoir for continuous reinfection within the Peruvian Amazon region, these results also indicate that clinical immunity in human populations can be driven in malaria-endemic regions that do not have high intensity malaria transmission
CHRONIC CEREBRAL PARAGONIMIASIS COMBINED WITH ANEURYSMAL SUBARACHNOID HEMORRHAGE
Authors: CHOO JUK-DONG , SUH BUMN-SUK , LEE HYUN-SUNG , LEE JONG-SOO , SONG CHANG-JUNE , SHIN DAE-WHAN , LEE YOUNG-HA
Published: September 2018

A 67-year-old Korean woman attended our hospital complaining of a severe headache. A brain computed tomography scan showed conglomerated, high-density, calcified nodules in the left temporo-occipito-parietal area and high-density subarachnoid hemorrhage in the basal cisterns. Magnetic resonance imaging of the brain shows multiple conglomerated iso- or low-signal intensity round nodules with peripheral rim enhancement. She underwent craniotomies to clip the aneurysm and remove the calcified masses. Paragonimus westermani eggs were identified in the calcified necrotic lesions. Results of parasitic examinations on the sputum and an enzyme-linked immunosorbent assay for P. westermani were all negative. The patient presented with headache and dizziness that had occurred for more than 30 years. She had not eaten freshwater crayfish or crabs. However, she had sometimes prepared raw crabs for several decades. Overall, this case was diagnosed as chronic cerebral paragonimiasis, in which she may have been infected through the contamination of utensils during the preparation of the second intermediate hosts, combined with a cerebral hemorrhage.
SHORT REPORT: IN VIVO SENSITIVITY OF PLASMODIUM FALCIPARUM TO HALOFANTRINE IN SOUTHERN CENTRAL VIETNAM
Authors: NHAN DOAN HANH , TAYLOR WALTER R. J. , THUONG NGUYEN DIEU , UYEN TRAN THI , FRYAUFF DAVID J. , SUSANTI IKA , GÓMEZ-SALADÍN EDUARDO , CONG LE DINH , BAIRD J. KEVIN
Published: September 2018

Drug-resistant Plasmodium falciparum is present in Vietnam. We assessed the in vivo sensitivity of P. falciparum to halofantrine in two villages in the southern part of central Vietnam. Halofantrine (8 mg/kg × 3 doses) was administered to 37 patients with either P. falciparum (n = 32) or mixed P. falciparum/P. vivax malaria (n = 5). End points were parasite sensitivity or resistance (RI/RII/RIII) determined by parasite clearance, persistence, or recurrence during 28 days of follow-up. By day 28, 31 (93.9%) of 33 (95% confidence interval = 79.8–99.2%) patients were sensitive. Two patients had recurrent P. falciparum parasitemia on days 14 and 21. Halofantrine effectively treated uncomplicated P. falciparum malaria in these Vietnamese patients.
CLEARANCE OF DRUG-RESISTANT PARASITES AS A MODEL FOR PROTECTIVE IMMUNITY IN PLASMODIUM FALCIPARUM MALARIA
Authors: DJIMDÉ ABDOULAYE A. , DOUMBO OGOBARA K. , TRAORE OUSMANE , GUINDO ANDO B. , KAYENTAO KASSOUM , DIOURTE YACOUBA , NIARE-DOUMBO SAFIATOU , COULIBALY DRISSA , KONE ABDOULAYE K. , CISSOKO YACOUBA , TEKETE MAMADOU , FOFANA BAKARY , DICKO ALASSANE , DIALLO DAPA A. , WELLEMS THOMAS E. , KWIATKOWSKI DOMINIC , PLOWE CHRISTOPHER V.
Published: September 2018

Residents of malaria-endemic areas sometimes spontaneously clear Plasmodium falciparum infection without drug treatment, implying an important role for host factors such as immunity in this clearance. Host factors may also contribute to clearance of parasites resistant to a treatment drug. Chloroquine resistance is caused by point mutations in P. falciparum chloroquine resistance transporter (pfcrt) gene. We investigated the clearance of malaria parasites carrying the key chloroquine resistance-conferring PfCRT mutation K76T in patients treated with chloroquine. We found that the ability to clear these resistant parasites is strongly dependent on age (the best surrogate for protective immunity in endemic areas), suggesting that host immunity plays a critical role in the clearance of resistant P. falciparum infections. Age-adjusted comparison of subjects able to clear resistant parasites and those unable to do so provides a new phenotype for identifying host immune and genetic factors responsible for protective immunity against malaria.
USE OF A GEOGRAPHIC INFORMATION SYSTEM FOR DEFINING SPATIAL RISK FOR DENGUE TRANSMISSION IN BANGLADESH: ROLE FOR AEDES ALBOPICTUS IN AN URBAN OUTBREAK
Authors: ALI MOHAMMAD , WAGATSUMA YUKIKO , EMCH MICHAEL , BREIMAN ROBERT F.
Published: September 2018

We used conventional and spatial analytical tools to characterize patterns of transmission during a community-wide outbreak of dengue fever and dengue hemorrhagic fever in Dhaka, Bangladesh in 2000. A comprehensive household-level mosquito vector survey and interview was conducted to obtain data on mosquito species and breeding as well as illness consistent with dengue. Clusters of dengue illnesses and high-density vector populations were observed in a distinct sector of the city. Dengue clusters are less identifiable in areas further away from major hospitals, suggesting that proximity to hospitals determines whether cases of dengue are diagnosed. Focusing on those areas relatively close to hospitals, we found a spatial association between dengue clusters and vector populations. Households reporting a recent dengue illness were more likely to have Aedes albopictus larvae present in the home when compared with households not reporting cases. Households reporting a recent dengue illness were also more likely to have a neighbor with Ae. albopictus present in the home. In contrast, the presence of Aedes aegypti within the premises as well as the homes of neighbors (within 50 meters) was not associated with dengue illness. Given that the breeding habitats for Ae. albopictus are somewhat distinct from those of Ae. aegypti, the findings of this study have implications for control of dengue transmission in this urban setting where much of the focus has been on indoor mosquito breeding and transmission. Public health officials may find the disease-environment map useful for planning targeted interventions because it displays areas where transmission is most intense.
STUDY OF LYSSAVIRUSES OF BAT ORIGIN AS A SOURCE OF RABIES FOR OTHER ANIMAL SPECIES IN THE STATE OF RIO DE JANEIRO, BRAZIL
Authors: ROMIJN PHYLLIS C. , VAN DER HEIDE REINA , CATTANEO CARLOS ALBERTO M. , DE CÁSSIA F. SILVA RITA , VAN DER POEL WIM H. M.
Published: September 2018

An epidemic-geographic rabies study was carried out in which 72 animal and human brain samples were analyzed for Lyssaviruses by a direct immunofluorescent technique (DIFT) and a reverse transcriptase-polymerase chain reaction (RT-PCR) assay. Fifty-two samples were also tested by a mouse inoculation test. Lyssavirus RNA was detected in 60 of 72 samples. Five DIFT-negative bat samples tested by a nested PCR assay showed evidence of the presence of rabies virus RNA. Sequencing of amplified rabies virus nucleoprotein encoding segments of a selection of the samples resulted in the formation of clusters, corresponding to samples originating from cattle and equines from the same hydrographic basin. Genomically related Lyssavirus strains of bat origin were found in each cluster, most likely because of the role of the bat in the epidemiology of the virus. All samples studied were of genotype 1. With exception of the human sample, all were distinct from the reference sample.
LABORATORY EVALUATION OF THE ICT MALARIA P.F./P.V. IMMUNOCHROMATOGRAPHIC TEST FOR DETECTING THE PANMALARIAL ANTIGEN USING A RODENT MALARIA MODEL
Authors: ARAI MEIJI , ISHII AKIRA , MATSUOKA HIROYUKI
Published: September 2018

We evaluated the ICT Malaria P.f./P.v. immunochromatographic test for the detection of the panmalarial antigen (PMA) using a rodent malaria model. Mice were infected with Plasmodium berghei by mosquito bite, and blood was examined by microscopy and the ICT test. Treatment with artemether was started when the parasite density exceeded 70,000/μL. The ICT PMA band appeared when the parasite density was more than 2,000/μL, but it continued to be positive after the parasitemia became negative in response to the drug treatment. When all the test results were divided into increasing phase (IP) and declining phase (DP), the sensitivity in the DP was significantly higher than that in the IP, suggesting that the reactivity of the ICT PMA is significantly influenced by persistent and accumulated PMA after drug treatment and longer duration of infection in the DP. Recognizing that the patient population in a clinical situation would be a mixture of individuals in the IP and DP, it should be emphasized that the individual history of recent fever, duration of illness, and drug treatment must be considered carefully for the interpretation of the ICT results.
SHORT REPORT: MODULATION OF MYCOBACTERIUM TUBERCULOSIS INFECTION BY PLASMODIUM IN THE MURINE MODEL
Authors: SCOTT CHERISE P. , KUMAR NIRBHAY , BISHAI WILLIAM R. , MANABE YUKARI C.
Published: September 2018

A large proportion of people with latent tuberculosis live in malaria-endemic areas, so co-infection with these two organisms is likely to be common. To determine whether there might be a biologic interaction between these two pathogens in vivo, we infected mice with Mycobacterium tuberculosis and then with a non-lethal strain of Plasmodium yoelii eight weeks later. Mice chronically infected with M. tuberculosis simulate the equilibrium between pathogen and host thought to exist in human latent infection. Co-infected mice were less able to contain growth of M. tuberculosis in lung, spleen, and liver (mean ± SEM log10 colony-forming units = 5.50 ± 0.11 versus 5.12 ± 0.08, 4.58 ± 0.07 versus 4.13 ± 0.10, and 2.86 ± 0.10 versus 2.49 ± 0.10, respectively) and had increased mortality. In populations where both diseases are endemic, there may be implications for increased incidence of clinically detectable tuberculosis.
A DECREASE IN MOTHER-TO-CHILD TRANSMISSION OF HUMAN T LYMPHOTROPIC VIRUS TYPE I (HTLV-I) IN OKINAWA, JAPAN
Authors: KASHIWAGI KENICHIRO , FURUSYO NORIHIRO , NAKASHIMA HISASHI , KUBO NORIHIKO , KINUKAWA NAOKO , KASHIWAGI SEIZABURO , HAYASHI JUN
Published: September 2018

To investigate the chronologic change of mother-to-child transmission of human T lymphotropic virus type I (HTLV-I) in Okinawa, Japan, the presence of antibody to HTLV-I was tested in 4,187 healthy residents between, 4,528 nursery school children, and 3,837 pregnant women between 1968 and 2000. The chronologic change of the feeding method and the length of the breast-feeding period among 1,117 healthy mothers from 1937 to 1995 were also obtained by interview. Age-adjusted prevalence of HTLV-I among healthy residents decreased from 9.1% in 1968–1970 to 7.8% in 1981–1984 and to 6.3% in 1996–1998. The crude prevalence of antibody to HTLV-I among healthy residents less than 20 years old decreased significantly from 4.6% in 1968–1970 to 0.1% in 1996–1998 (P < 0.0001). The prevalence of antibody to HTLV-I among nursery school children decreased significantly over the study period, from a high of 1.8% in 1984 to a low of 0.2% in 1998 (P = 0.03). The prevalence among pregnant women decreased significantly from 5.6% in 1989–1992 to 3.7% in 1997–2000 (P = 0.0275). Prior to 1967, all healthy mothers breast-fed their children. After 1968, the use of bottled and mixed milk (breast milk and bottled milk) increased, with bottled milk becoming predominant after 1990 (89%). The percentage of healthy mothers breast-feeding for more than one year significantly decreased from 68.3% in 1937–1947 to 0.4% in 1990–1995 (P < 0.0001). Infection with HTLV-I in Okinawa has decreased mainly due to a reduction in the number of mothers breast-feeding and a shortening of the breast-feeding period. However, because the mother-to-child transmission rate among non-breast-feeders decreased from 12.8% in 1986–1991 to 3.2% in 1995–1999, there may be other factors involved in the decrease in mother-to-child transmission.
A FAMILY STUDY OF LYMPHEDEMA OF THE LEG IN A LYMPHATIC FILARIASIS–ENDEMIC AREA
Authors: CUENCO KAREN T. , HALLORAN M. ELIZABETH , LOUIS-CHARLES JACKY , LAMMIE PATRICK J.
Published: September 2018

The risk of filarial lymphedema may not be equivalent for all members of filaria-exposed populations. While evidence for a genetic factor that influences acquisition of infection has been growing, very little work has addressed whether there is a genetic basis to the development of disease due to lymphatic filariasis. We designed a family study of lymphedema in a rural community in Haiti to assess disease aggregation. Three hundred sixty-eight female patients sixteen years of age or older were enrolled at a lymphedema treatment clinic between June 1995 and December 1999. After applying additional eligibility criteria, 172 probands were enrolled into the family study for detailed pedigree collection between September 1998 and December 1999. Fifty-three lymphedema cases were identified among the probands’ parents, full-siblings, children, half-siblings, and mating partners of the parents. Twelve of the 53 cases were among males. The proportion of cases occurring in a biologic parent of the proband was higher than in unrelated individuals married into the proband’s family (P = 0.0010). This is the first large family study based on pedigrees to assess the familial aggregation of lymphedema due to filariasis. This family study will be useful to investigate the role of genes and environment in the development of filarial-related lymphedema.
RESTRICTION FRAGMENT LENGTH POLYMORPHISM METHOD FOR THE IDENTIFICATION OF MAJOR AFRICAN AND ASIAN MALARIA VECTORS WITHIN THE ANOPHELES FUNESTUS AND AN. MINIMUS GROUPS
Authors: GARROS C. , KOEKEMOER L. L. , KAMAU L. , AWOLOLA T. S. , VAN BORTEL W. , COETZEE M. , COOSEMANS M. , MANGUIN S.
Published: September 2018

The African Anopheles funestus and the Asian An. minimus groups are closely related and are probably considered distinct only because of their geographic separation. This study aimed at improving two identification methods based on polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) already developed for either group. Each PCR-RFLP, either on the internal transcribed spacer 2 (ITS2) for the An. minimus group, and domain 3 (D3) for the An. funestus group, was applied to the other group for the standardization of one identification method applicable on both continents. The ITS2 fragment digested by Bsi ZI showed the highest diagnostic power. This assay allowed the discrimination of at least 13 Anopheles species within the subgenus Cellia from two continents (Africa and Asia), among which are five major malaria vectors. Moreover, digestion of the D3 with Msp I showed intragenomic variations within An. funestus populations. Two types of D3 copies (M and W) occurred in specimens from southern Africa. The populations from West-Central Africa presented only type W and East-Malagasy populations exhibited type M. Since An. funestus shows a great capacity of adaptation, these molecular variations, along with behavioral and ecologic ones, reinforce the hypothesis of a species complex that will need to be further investigated.
COMMUNITY- AND INDIVIDUAL-LEVEL DETERMINANTS OF WUCHERERIA BANCROFTI INFECTION IN LEOGANE COMMUNE, HAITI
Authors: BOYD HEATHER A. , WALLER LANCE A. , FLANDERS W. DANA , BEACH MICHAEL J. , SIVILUS J. SONY , LOVINCE RODRIGUE , LAMMIE PATRICK J. , ADDISS DAVID G.
Published: September 2018

We conducted a school-based assessment of the geographic distribution of Wuchereria bancrofti infection in Leogane Commune, Haiti, using the immunochromatographic test. In multivariate analyses performed using generalized linear mixed models, children attending schools in the foothills and plains were 3.95 (95% confidence interval [CI] = 1.28–12.23) and 23.56 (95% CI = 8.99–61.79) times as likely to be infected, respectively, as children attending mountain schools. Infection prevalence decreased with increasing altitude, but some local foci of infection were detected at higher altitudes. Higher school tuition, a marker of socioeconomic status (SES), was not associated with decreased infection prevalence. Our results indicate that although the force of infection in Leogane Commune is greatest below 70 meters above sea level, higher altitude communities are not exempt from infection. Lymphatic filariasis (LF) elimination programs should consider extending infection mapping activities to presumed non-LF altitudes. In addition, higher SES does not confer protection against W. bancrofti infection.
ANTIGENIC DIVERSITY IN MAXADILAN, A SALIVARY PROTEIN FROM THE SAND FLY VECTOR OF AMERICAN VISCERAL LEISHMANIASIS
Authors: MILLERON RANIA S. , MUTEBI JOHN-PAUL , VALLE SONIA , MONTOYA ALBERTO , YIN HUAIZHI , SOONG LYNN , LANZARO GREGORY C.
Published: September 2018

The salivary protein maxadilan (MAX) is a vasodilator and immunomodulator from the sand fly vector of the protozoan parasite Leishmania chagasi. Vaccinating BALB/c mice with sand fly salivary gland extracts or with MAX protects the host against L. major infection. Because of the potential use of MAX in an anti-Leishmania vaccine, we characterized the vertebrate host IgG response to MAX in the present study. Our immunochemical analysis indicated that antibodies to MAX were detected in BALB/c mice, as well as in pigs and humans, from a area in Nicaragua endemic for Lutzomyia longipalpis. Previous studies demonstrate that the MAX protein is polymorphic on the amino acid level. Our findings suggested that naturally occurring MAX variants were recognized specifically by the host immune system and antigenicity appeared to be associated with amino-acid sequence variability. Thus, antigenic diversity of MAX and possibly of other arthropod salivary proteins may dictate the development of vector-based vaccines(s).
EFFECT OF TEMPERATURE STRESS ON IMMATURE STAGES AND SUSCEPTIBILITY OF AEDES AEGYPTI MOSQUITOES TO CHIKUNGUNYA VIRUS
Authors: MOURYA D. T. , YADAV P. , MISHRA A. C.
Published: September 2018

A high temperature stress of 44.5°C for 10 minutes on the larval stages was found to affect the susceptibility of adult Aedes aegypti mosquitoes to chikungunya virus. At this temperature, the mortality of the mosquito larvae was found to be approximately 95%, whereas a temperature greater than 45°C for 10 minutes was found to be lethal. A temperature tolerant (TT) strain was developed by exposing the larvae to a temperature of 44.5°C for 10 minutes at every generation for five generations. This strain was established to determine whether increase in the susceptibility was due to any selection pressure of higher temperature or to the influence of other intrinsic factors such as expression of immunoresponsive (IR) genes. Other studies on these mosquito strains showed that when maintained at 28 ± 1°C, there was no difference in the larval duration and mortality in the immature stages, but the mean survival of female mosquitoes in the TT strain was 5–6 days longer. Conversely, when mosquitoes were maintained throughout at 37°C the mean survival of the mosquitoes decreased drastically in both strains, but the mean survival of females in the TT strain was 5–6 days longer compared with the unstressed controls. This increases the probability of at least one more blood meal. Fecundity of the TT strain was found to be lower than that of the control mosquitoes. Data suggest that expression of certain IR genes was affected by the heat shock. Some of these genes were up-regulated and down-regulated, which may have affected the susceptibility of mosquitoes to the virus. Although there was some selection in the temperature-tolerant individuals in the TT strain, when stressed by heat they showed expression of IR genes in a pattern similar to that in the normal controls. It appears that an increase in temperature above the average temperature of an area might help increase the proportion of virus-susceptible mosquitoes in the population. Such an increase in temperature in an endemic area would not only enhance the selection of temperature-tolerant individuals in a population having more longevity, but would also affect both intrinsic and extrinsic factors by reducing the extrinsic incubation period and increasing susceptibility of mosquitoes to viruses due to affected expression of IR genes.
PARAMETERS OF LEISHMANIA BRAZILIENSIS TRANSMISSION BY INDOOR LUTZOMYIA OVALLESI IN VENEZUELA
Authors: RABINOVICH JORGE E. , FELICIANGELI M. DORA
Published: September 2018

We developed a mathematical model of cutaneous leishmaniasis (CL) transmission predicting CL incidence based on field data of number of positive sand flies, new CL cases, and number of susceptible people. We estimated the following parameters: a CL incubation period of one month, the overall susceptibility (Φ = 0.793), the serologic force of infection (λm = 0.108 /person/year, SD = 0.014), the clinical force of infection (λl= 0.114/year), the proportion of infections that result in skin lesions (α = 1.056), and the instantaneous reversal rate of Montenegro skin test-positive (MST+) people to MST− (ρ= 0.124/year, SD = 0.021). We also provide the first field estimate of the transmission efficiency (ε = 0.0045, SD = 0.0009). The model predictions conform well with the observed new cases except for some small departures in the peaks and in some depressions (Dmax = 0.1494, P < 0.2). We discuss possible sources of error of our estimate of ε, and compare our parameter estimates with those obtained in Peru.
IRRITABLE BOWEL SYNDROME: IN SEARCH OF AN ETIOLOGY: ROLE OF BLASTOCYSTIS HOMINIS
Authors: YAKOOB JAVED , JAFRI WASIM , JAFRI NADIM , KHAN RUSTAM , ISLAM MUHAMMAD , BEG M. ASIM , ZAMAN VIQAR
Published: September 2018

This study was designed to examine stool specimens of irritable bowel syndrome (IBS) patients for Blastocystis hominis, a common intestinal parasite. One hundred fifty patients were enrolled, 95 IBS cases and 55 controls. These patients provided a medical history, and underwent physical and laboratory evaluations that included stool microscopy and culture for B. hominis and colonoscopy. The 95 cases (51 males and 44 females) had a mean ± SD age of 37.8 ± 13.2 years. Stool microscopy was positive for B. hominis in 32% (30 of 95) of the cases and 7% (4 of 55) of the controls (P = 0.001). Stool culture was positive in 46% (44 of 95) of the cases and 7% (4 of 55) of the controls (P < 0.001). Stool culture for B. hominis in IBS was more sensitive than microscopy (P < 0.001). Blastocystis hominis was frequently demonstrated in the stool samples of IBS patients; however, its significance in IBS still needs to be investigated. Stool culture has a higher positive yield for B. hominis than stool microscopy.
ETHNIC DIFFERENCES IN POLYMORPHISMS OF TUMOR NECROSIS FACTOR-α, INTERLEUKIN-10, AND TRANSFORMING GROWTH FACTOR-β1 GENES IN PATIENTS WITH CHRONIC HEPATITIS C VIRUS INFECTION
Authors: ZEIN NIZAR N. , GERMER JEFFREY J. , EL-ZAYADI ABDEL R. , VIDIGAL PEDRO G.
Published: September 2018

Ethnic differences in the outcome of hepatitis C have been described. Our aim was to investigate ethnic differences in the distribution of genotypes associated with polymorphisms of the tumor necrosis factor-α promoter, interleukin-10 promoter, and transforming growth factor-β1 leader sequence in patients with hepatitis C. Genomic DNA was obtained from 71 Egyptians and 67 Caucasians (hepatitis C and control patients). Amplification of appropriate gene segments was followed by direct sequencing. Infrequently occurring polymorphisms were identified at positions −244 and −77 of the tumor necrosis factor-α promoter and at positions −851 and −657 of the interlukin-10 promoter. The G/A genotype associated with tumor necrosis factor-α promoter positions −376 and −244 was more frequent in Egyptians (P =0.001 and P =0.004, respectively). The −244 G/A genotype occurred only in healthy Egyptians (P =0.024). Thus, ethnic differences in the distribution of genotypes of the tumor necrosis factor-α promoter exist, which may have clinical implications on the outcome of hepatitis C.
DISTRIBUTION PATTERNS AND CERCARIAL SHEDDING OF BULINUS NASUTUS AND OTHER SNAILS IN THE MSAMBWENI AREA, COAST PROVINCE, KENYA
Authors: KARIUKI H. CURTIS , CLENNON JULIE A. , BRADY MELINDA S. , KITRON URIEL , STURROCK ROBERT F. , OUMA JOHN H. , NDZOVU SAIDI TOSHA MALICK , MUNGAI PETER , HOFFMAN ORIT , HAMBURGER JOSEPH , PELLEGRINI CARA , MUCHIRI ERIC M. , KING CHARLES H.
Published: September 2018

In the Msambweni area of the Kwale District in Kenya, an area endemic for Schistosoma haematobium, potential intermediate-host snails were systematically surveyed in water bodies associated with human contact that were previously surveyed in the 1980s. Bulinus (africanus) nasutus, which accounted for 67% of the snails collected, was the only snail shedding S. haematobium cercariae. Lanistes purpureus was the second most common snail (25%); lower numbers of Bulinus forskalii and Melanoides tuberculata were also recovered. Infection with non-S. haematobium trematodes was found among all snail species. Rainfall was significantly associated with the temporal distribution of all snail species: high numbers of Bulinus nasutus developed after extensive rainfall, followed, in turn, by increased S. haematobium shedding. Spatial distribution of snails was significantly clustered over a range of up to 1 km, with peak clustering observed at a distance of 400 meters. Water lily (Nymphaea spp.) and several aquatic grass species appeared necessary for local colonization by B. nasutus or L. purpureus.
PATTERNS OF WEST NILE VIRUS INFECTION IN OHIO BLUE JAYS: IMPLICATIONS FOR INITIATION OF THE ANNUAL CYCLE
Authors: GARVIN MARY C. , TARVIN KEITH A. , SMITH JENNIFER , OHAJURUKA OJIMADU A. , GRIMES SHEILA
Published: September 2018

West Nile virus (WNV) was first detected in North America in New York City in 1999 and rapidly moved westward. Understanding the mechanisms by which the amplification cycle is reinitiated each year increases our ability to predict epizootics and geographic expansion of the disease. Such understanding is enhanced by knowledge of the patterns of infection in the vertebrate reservoir hosts. Blue jays (Cyanocitta cristata) may serve as reservoir hosts for WNV. We examined the influence of age and date on the prevalence of WNV in jay carcasses in Ohio during May–August 2002. Percent of carcasses that were infected increased significantly with time from 3% in May to more than 90% by August. We found no difference in prevalence between juvenile (nestlings and fledglings) and adult jays early in the season, which contradicts the expected pattern if the majority of the adults sampled in 2002 had been exposed to the virus in 2001. Therefore, jays infected in 2001 were unlikely to have been important in initiating the 2002 virus cycle in Ohio.
STUDIES ON CULTURED AND UNCULTURED MICROBIOTA OF WILD CULEX QUINQUEFASCIATUS MOSQUITO MIDGUT BASED ON 16S RIBOSOMAL RNA GENE ANALYSIS
Authors: PIDIYAR VYANKATESH J. , JANGID KAMLESH , PATOLE MILIND S. , SHOUCHE YOGESH S.
Published: September 2018

To describe the midgut microbial diversity and the candidate bacteria for the genetic manipulation for the generation of transgenic mosquitoes refractory to transmission of diseases, the microbiota of wild Culex quinquefasciatus mosquito midgut was studied using a conventional culture technique and analysis of a 16S ribosomal RNA (rRNA) gene sequence library. The culturable microbiota was identified as Acinetobacter junii, Ac. calcoaceticus, Aeromonas culicicola, Bacillus thuringiensis, Microbacterium oxydans, Pantoea agglomerans, Pseudomonas aeruginosa, Staphylococcus epidermidis, Stenotrophomonas maltophila and an unidentified bacterium from the host Drosophila paulistorium. The 16S rRNA gene library was composed of 46% unidentified and uncultured bacteria, 41% Acinetobacter spp., and 13% Lactococcus spp. The coverage calculated for the 150 clones was 83.3%. Thus, the probability of the next cloned sequence falling in a novel operational taxonomic unit (not yet observed) was 16.7%. The majority of the cultured isolates and the 16S rRNA gene library clones belonged to the γ-proteobacteria class. Most of the bacteria have been previously reported to inhabit the midgut of different mosquito species. Therefore, the results of this study indicate that different mosquito species harbor common representatives of the microbiota that may be the potential candidates for genetic manipulation to control the disease transmission capabilities of the host.
DIRECT AGGLUTINATION TEST WITH URINE SAMPLES FOR THE DIAGNOSIS OF VISCERAL LEISHMANIASIS
Authors: ISLAM MOHAMMAD ZAHIDUL , ITOH MAKOTO , MIRZA RUSELLA , AHMED IFTIKHAR , EKRAM A. R. M. SAIFUDDIN , SARDER ABDUL HALIM , SHAMSUZZAMAN S. M. , HASHIGUCHI YOSHIHISA , KIMURA EISAKU
Published: September 2018

A new direct agglutination test (DAT) for use with urine samples for the diagnosis of visceral leishmaniasis (VL) has been developed and compared with the conventional DAT with serum samples and our previously reported enzyme-linked immunosorbent assay (ELISA) with urine samples (urine ELISA). The new DAT, in which anti-human IgG was used as enhancing antibody, was tested with urine samples from 75 VL patients and 225 non-VL patients and healthy people. The sensitivity of the new DAT (90.7%), was almost the same as that of the conventional DAT (91.0%) and the urine ELISA (93.3%). The specificity of the new DAT (96.4%) was nearly identical with that of the urine ELISA (97.3%). A urine-based DAT has several advantages over the conventional DAT: sample collection is non-invasive and it can process larger numbers of samples with smaller amounts of antigen.
ANALYSIS OF THE REPLICATION KINETICS OF THE CHIMERIVAX™-DEN 1, 2, 3, 4 TETRAVALENT VIRUS MIXTURE IN AEDES AEGYPTI BY REAL-TIME REVERSE TRANSCRIPTASE–POLYMERASE CHAIN REACTION
Authors: JOHNSON BARBARA W. , CHAMBERS TRUDY V. , CRABTREE MARY B. , GUIRAKHOO FARSHAD , MONATH THOMAS P. , MILLER BARRY R.
Published: September 2018

The vector competence of mosquitoes for chimeric viruses being developed as vaccines to protect against dengue (DEN) virus infection were evaluated in a cooperative agreement with Acambis, Inc. Chimeric viruses have been constructed that contain the premembrane (prM) and envelope (E) genes of each of the wild-type (wt) DEN virus serotypes, DEN-1, DEN-2, DEN-3, and DEN-4, in the yellow fever (YF) vaccine virus (strain 17D) YF-VAX backbone. It was previously shown that the replication profile of ChimeriVax™-DEN2 virus in Aedes albopictus C6/36 cells and in vivo in Ae. aegypti mosquitoes corresponded to that of YF-VAX virus; replication was restricted in C6/36 cells, and Ae. aegypti were poorly infected via an artificial infectious blood meal. Thus, there is very little risk of transmission by mosquitoes of ChimeriVax-DEN2 vaccine virus through the bite of a mosquito. However, because ChimeriVax™-DEN 1, 2, 3, 4 viruses will be administered to humans simultaneously, growth of a mixture of ChimeriVax™-DEN 1, 2, 3, 4 viruses was assessed in both C6/36 cells in culture and in the Ae. aegypti mosquito, which is the primary vector of both YF and DEN viruses. Mosquitoes were intrathoracically (IT) inoculated with virus or fed a virus-laden blood meal, and the replication kinetics of ChimeriVax™-DEN 1, 2, 3, 4 were compared with the wt DEN and YF-VAX viruses. A quantitative real-time reverse transcriptase-polymerase chain reaction assay was developed as a method to detect and differentiate replication of each of the four ChimeriVax™-DEN serotypes in the ChimeriVax™-DEN 1, 2, 3, 4 tetravalent mixture. Growth of the chimeric viruses in C6/36 cells and in IT-inoculated Ae. aegypti was lower than that of YF-VAX virus; in previous studies Ae. aegypti was shown to be refractory to infection by YF-VAX virus. The growth rate of each chimeric virus was similar whether it was a single serotype infection, or part of the tetravalent mixture, and no interference by one chimeric virus over another chimeric serotype was observed. ChimeriVax™-DEN viruses infected mosquitoes poorly via an infectious blood meal compared with wt DEN viruses. Therefore, it is unlikely that a mosquito feeding on a viremic vaccinee, would become infected with the chimeric viruses. Thus, there is very little potential for transmission by mosquitoes of the ChimeriVax-DEN vaccine viruses.
INTEGRATED URBAN MALARIA CONTROL: A CASE STUDY IN DAR ES SALAAM, TANZANIA
Authors: DE CASTRO MARCIA CALDAS , YAMAGATA YOICHI , MTASIWA DEO , TANNER MARCEL , UTZINGER JÜRG , KEISER JENNIFER , SINGER BURTON H.
Published: September 2018

The rapid growth of cities in sub-Saharan Africa, much of it driven by rural-urban migration, is associated with complex transformations of these ecosystems and an intricate set of challenges for malaria control. Urban malaria transmission is substantially less intense and much more focal than in rural and peri-urban settings. However, the danger of epidemics is higher and the presence of substantial non-immune populations places people of all ages at comparable levels of risk. The limited number of breeding sites in urban centers suggests that prevention strategies based on vector control, with emphasis on environmental management, should be a central feature of urban malaria control programs. We focus on malaria in the city of Dar es Salaam, Tanzania. Following a brief review of the 100-year history of malaria control in this urban center, we describe and evaluate a control program that operated from 1988 to 1996 as a consequence of a bilateral agreement between the governments of Tanzania and Japan. We present an innovative urban malaria risk mapping methodology based on high-resolution aerial photography with ground-based validation. This strategy clarifies that remote sensing technology at a level of resolution of one meter is essential if this kind of information is to play a role in guiding the detailed specification of intervention strategies for urban malaria control. The Tanzania-Japan multiple-intervention malaria control program, adaptively implemented over time, is described and evaluated with implications for urban malaria control in sub-Saharan Africa more generally.