bluuebunny/crossref_metadata_2025 huggingface dataset:
Santo InÃ¡cio revisited: protozoan diseases in an isolated village in northeastern Brazil after twenty years.
Authors: Cerqueira R L , Kawarabayashi M , GuimarÃ£es A C , Nakamura P M , Ferraz S N , Pinto P L , de Andrade H F
Published: May 2017

The northeastern highlands of Brazil are endemic for several tropical diseases, especially American trypanosomiasis (Chagas' disease) and schistosomiasis. Twenty years ago, we measured the seroprevalence of protozoan diseases in Santo InÃ¡cio, a village of approximately 1,000 inhabitants located 1,000 m above sea level. We detected small numbers of sera with antibodies against Trypanosoma cruzi and Toxoplasma gondii, and the area had a low prevalence both of American trypanosomiasis (3.54%) and toxoplasmosis (27.43%) compared with nearby Brazilian areas. This was attributed to a specific triatomine vector and local housing conditions. Twenty years later, we again determined the prevalences of both diseases and compared these results with those from Iraquara, a larger town with the same ethnic and social background but with a higher prevalence of rural activities. The incidence of Chagas' disease in San InÃ¡cio showed the same low level, i.e., 3.78% (5 of 132) with only adult males affected in contrast with Iraquara, which had an incidence of 34.5%, but a low prevalence of only one of 22 among children up to 14 years of age. Santo InÃ¡cio maintained a low (25.8%) seroprevalence for toxoplasmosis. Housewives presented a higher incidence of toxoplasmosis during both periods, probably due to related risk factors. Cats were found less frequently in Santo InÃ¡cio than in Iraquara, which showed an incidence of 65.5% seropositivity for Toxoplasma gondii. These results suggest that the environmental conditions of Santo InÃ¡cio were preserved after 20 years, with a low incidence of these selected protozoan diseases.
Neotropical echinococcosis in Suriname: Echinococcus oligarthrus in the orbit and Echinococcus vogeli in the abdomen.
Authors: Basset D , Girou C , Nozais I P , D'Hermies F , Hoang C , Gordon R , D'Alessandro A
Published: May 2017

This paper reports two cases of neotropical echinococcosis caused by Echinococcus oligarthrus and E. vogeli, neither of which has been reported from Suriname. Case 1, a six-year-old boy, presented a 15 x 25 mm retro-ocular cystic tumor (observed by ultrasound, computed tomography scan, and magnetic resonance imaging) causing exophthalmia, chemosis, palpebral ptosis, and blindness of the left eye. Of two tentative diagnoses, Echinococcus cyst or dermoid tumor, the former was shown to be correct at surgery when a clear liquid and detached protoscoleces were aspirated. Rostellar hooks of the protoscolex were characteristic of E. oligarthrus. Case 2, a 41-year-old man, had polycystic masses excised from the liver and abdomen. A presurgery diagnosis of E. vogeli infection was made due to calcifications seen in the lesions, positive serology, residence of the patient in the tropical forest, and later by the size and shape of rostellar hooks. The presence of these two parasites in one of the former Guianas is not surprising; both species are endemic in tropical forest in Central and South America wherever people have not exterminated wild canids, especially the bush dog, (Speothos venaticus), and felids (wild cats of several species), along with pacas, agoutis, and other rodents that serve as intermediate host of these two cestodes. Eighty-six cases of polycystic echinococcosis are known in people from 11 countries from Nicaragua to Argentina: 32 due to E. vogeli, three to E. oligarthrus, and 51 for which determination of the species was not possible because the hooks of the protoscolex were not found or described. Research to elucidate aspects of transmission of E. vogeli and E. oligarthrus is of practical importance for defining measures for preventing the severe and frequently fatal illnesses caused by these two cestodes.
Epidemiologic, genetic, and clinical associations among phenotypically distinct populations of Leishmania (Viannia) in Colombia.
Authors: Saravia N G , Segura I , Holguin A F , Santrich C , Valderrama L , Ocampo C
Published: May 2017

Phenotypic characterization of 511 strains of Leishmania, subgenus Viannia, isolated from Colombian patients was conducted based on electrophoretic polymorphisms of 13 isoenzymes. Ninety-one Colombian strains of L. braziliensis were the most heterogeneous, constituting seven zymodemes while 397 L. panamensis and 22 L. guyanensis strains yielded five and three zymodemes, respectively. Phosphogluconate dehydrogenase, nucleoside hydrolase, and superoxide dismutase were the most polymorphic enzymes in this collection of strains, and together with glucose-6-phosphate dehydrogenase, allowed the discrimination of the three aforementioned species. Hierarchical cluster analysis of the zymodemes using Jaccard's coefficient of similarities revealed two clusters, one constituted by L. braziliensis zymodemes, and another by three subgroups consisting of zymodemes of L. panamensis closely related to the species reference strain, another consisting of L. guyanensis zymodemes, and a third group distinguished by new electromorphs of proline iminopeptidase and aspartate aminotransferase that reacted with the L. panamensis-specific monoclonal antibody B-11. Multiple zymodemes of L. panamensis and L. guyanensis were found to be sympatrically transmitted in foci along the Pacific coast. Leishmania braziliensis variants were ubiquitous throughout the territory of Colombia; L. panamensis was prevalent in the western region and L. guyanensis was prevalent in the Orinoco and Amazon river basins in the eastern half of the country. Distinct zymodemes of L. panamensis predominated in the northern and southern regions of the Pacific coast. Nine zymodemes of all three species were isolated from mucosal lesions. Zymodeme 1.1 of L. braziliensis had the highest frequency of mucosal involvement (10% of the cases), and disease caused by this zymodeme had the longest mean time of evolution (31 months; P = 0.002). In addition to being useful in describing epidemiologic relationships, the intraspecific heterogeneity of strains of the Viannia subgenus within and among foci can be used to understand such fundamental questions as the pathogenicity of different populations of parasites, and the induction of cross-protection against related parasites.
Artesunate versus artemether for the treatment of recrudescent multidrug-resistant falciparum malaria.
Authors: Price R , van Vugt M , Nosten F , Luxemburger C , Brockman A , Phaipun L , Chongsuphajaisiddhi T , White N
Published: May 2017

The therapeutic efficacy and toxicity of artesunate (2mg/kg/day for five days, then 1 mg/kg/day for two days: total=12 mg/kg) was compared with that of artemether (4 mg/kg followed by 2 mg/kg/day for two days, then 1 mg/kg/day for four days: total=12 mg/kg) for the treatment of recrudescent multidrug-resistant falciparum malaria in an open randomized trial in 443 patients living on the western border of Thailand. Parasite and fever clearance times were similar in both groups; within 48 hr 94% (95% confidence interval [CI]=91-96%]) of the treated patients were aparasitemic and 93% (95% CI=89-96%) were afebrile. Symptom resolution and resolution of hepatomegaly were slightly slower in the artesunate group; adjusted hazards ratio=1.5 (95% CI=1-2.0, P < 0.01) and 2.2 (95% CI=1.4-8, P=0.04), respectively. There was no significant difference in times to resolution or development of anemia or splenomegaly between treatment groups. By day 28, 3% (95% CI=0.3-5%) of the patients treated with artesunate and 6% of those treated with artemether (95% CI = 2-9%) had recurrent infections (P=0.3). Both regimens were very well tolerated, with no significant adverse effects attributable to either derivative. Overall, these data suggest that the two oral artemisinin derivatives are safe, highly effective, and result in equivalent therapeutic responses in the treatment of drug-resistant falciparum malaria.
Lack of efficacy of mefloquine in the treatment of New World cutaneous leishmaniasis in Colombia.
Authors: Hendrickx E P , Agudelo S P , Munoz D L , Puerta J A , Velez Bernal I D
Published: May 2017

In a nonblinded, therapeutic trial conducted in Colombia, 1.25-1.5 grams of mefloquine base given as a single oral dose or as 250 mg a day for 5-6 consecutive days was not efficacious in the treatment of New World cutaneous leishmaniasis. The drug had cured only 30.8 % of patients with leishmaniasis skin lesions by the 10th week after start of therapy as compared with a 27.9% complete cicatrization rate in historical controls treated with placebo tablets and an 86.3% cicatrization rate in historical controls who received meglumine antimoniate, 20 mg/ kg/day intramuscularly for 20 days, with no upper limit to daily dose. It is concluded that a single course treatment with mefloquine is not indicated as monotherapy in the treatment of Colombian cutaneous leishmaniasis primarily due to L. panamensis.
Increased prevalence of cysticercosis and taeniasis among professional fried pork vendors and the general population of a village in the Peruvian highlands. Cysticercosis Working Group in Peru.
Authors: Garcia H H , Araoz R , Gilman R H , Valdez J , Gonzalez A E , Gavidia C , Bravo M L , Tsang V C
Published: May 2017

Two different populations in Saylla, a Peruvian village near Cusco, known for chicharrones, a local pork dish, were surveyed by serology and stool examination to determine the prevalence and epidemiologic characteristics of Taenia solium infection. Group I (n=43), the chicharroneros, were members of families professionally devoted to the making and selling of chicharrones, and Group II (n=102) was a sample of the general population of the same village. Unlike people in Group I, general villagers only occasionally prepare or sell this food product, and then only to their neighbors or relatives. The prevalence of taeniasis was extremely high (8.6%) for the chicharroneros and 3% for the general villagers. Seroprevalence for cysticercosis by immunoblot was similarly high in both groups (23.3% and 23.8%, respectively). Being female, older than 30, and having daily contact with pork were factors strongly associated with a positive serologic result for cysticercosis in the chicharroneros, whereas males were more frequently seropositive in the general villagers group. Antibody reaction to more antigen bands in immunoblots and neurologic symptoms were more common among the chicharroneros. Also, in the general villagers group, seroprevalence increased with each exposure factor, ranging from 9.4% in individuals who did not raise pigs to 50% in the small subgroup that raised pigs, butchered their own animals, sold pork, and sold chicharrones, suggesting that these activities are related to increased risk for tapeworm or larval infection.
Nucleotide sequences of the 26S mRNAs of the viruses defining the Venezuelan equine encephalitis antigenic complex.
Authors: Kinney R M , Pfeffer M , Tsuchiya K R , Chang G J , Roehrig J T
Published: May 2017

Genetic relationships among viruses defining the Venezuelan equine encephalitis (VEE) virus antigenic complex were determined by analyzing the 3'-terminal 561 nucleotides of the nonstructural protein 4 gene and the entire 26S RNA region of the genome. New sequence information is reported for VEE 78V-3531 (VEE subtype-variety IF), Mucambo (IIIA), Tonate (IIIB), 71D-1252 (IIIC), Pixuna (IV), Cabassou (V), and AG80-663 (VI) viruses. The results reported here and by previous investigators largely support the current classification scheme of these viruses, while clearly identifying Everglades (II) as a subtype I virus. A genetic relationship between 78V-3531 (IF) and AG80-663 (VI) viruses contradicted previous serologic results. Mutations near the amino terminus of the E2 envelope proteins of Pixuna and AG80-663 viruses probably account for the previously reported low reactivity of the protective monoclonal antibody 1A2B-10 with these two viruses. Variations in the distribution of potential glycosylation sites in the E2 glycoprotein are discussed.
Quantitative genetics of vector competence for dengue-2 virus in Aedes aegypti.
Authors: Bosio C F , Beaty B J , Black W C
Published: May 2017

A quantitative genetic study of the ability of Aedes aegypti to propagate dengue-2 (DEN-2) virus in the midgut and in a disseminated infection in the head was conducted with a standard half-sib breeding design. Aedes aegypti aegypti and A. aegypti formosus differ markedly in oral susceptibility to DEN-2 virus. Mosquitoes were orally infected and, after an extrinsic incubation period of 14 days, virus titer (by tissue culture infectious dose, 50% endpoint) was determined in the midgut (MT) and head (HT). Body size as measured by wing length was not significantly different between infected and uninfected mosquitoes and was not correlated with MT or HT The heritability for MT in both subspecies was 0.41 and was 0.39 for HT in A. aegypti formosus. In A. aegypti aegypti, HT appeared to be controlled by dominant alleles. The MT was not correlated with HT nor did MT determine whether virus disseminated out of the midgut. These results suggest that it is the barriers to infection and dissemination, independent of virus titer, that determine vector competence for DEN-2 virus.
In vitro susceptibility of African isolates of Plasmodium falciparum from Gabon to pyronaridine.
Authors: Pradines B , Mabika Mamfoumbi M , Parzy D , Owono Medang M , Lebeau C , Mourou Mbina J R , Doury J C , Kombila M
Published: May 2017

The in vitro activity of pyronaridine was evaluated against 62 isolates of Plasmodium falciparum from Libreville, Gabon using an isotopic, drug susceptibility microtest and was compared with amodiaquine, chloroquine, quinine, and halofantrine activities. The mean 50% inhibitory concentration (IC50) values of the 62 isolates from Gabon to pyronaridine was 3.0 nM (95% confidence interval [CI] = 2.1-3.9). Pyronaridine was less potent against chloroquine-resistant isolates than chloroquine-susceptible isolates but more potent than chloroquine against chloroquine-resistant parasites. The cut-off value for in vitro reduced susceptibility to pyronaridine was an IC50 > 15 nM. Two isolates (3%) showed an IC50 > 15 nM. A significant positive correlation was found between the activities of pyronaridine and chloroquine (r2 = 0.26, P < 0.001), pyronaridine and quinine (r2 = 0.36, P < 0.001), pyronaridine and amodiaquine (r2 = 0.55, P < 0.001), and pyronaridine and halofantrine (r2 = 0.50, P < 0.001). This correlation suggests in vitro cross-resistance or at least in vitro cross-susceptibility, which is not necessarily predictive of cross-resistance in vivo. The present in vitro findings require comparison with those of clinical studies.
Regulation of the mucosal immune response.
Authors: Ernst P B , Song F , Klimpel G R , Haeberle H , Bamford K B , Crowe S E , Ye G , Reyes V E
Published: May 2017

Infectious diseases continue to exact an extensive toll on populations living closest to the equatorial regions of the globe. A substantial proportion of these infections gain access to the host via the mucosal tissues. Thus, the development of new vaccines that enhance mucosal immunity is considered to be of paramount importance in order to prevent or limit the impact of these infections. Mucosal immune responses must discriminate between commensal flora within the lumen and potential pathogens. These responses are highly adapted to induce protection without excessive amounts of inflammation. The balances that regulate mucosal immune and inflammatory responses have to be understood if effective mucosal immunity is to be induced through local immunization. This review will summarize some of the unique properties of mucosal immune responses and focus on recent advances that have significantly influenced our understanding of the regulation of immune and inflammatory responses following infection.
Enzyme-linked immunosorbent assay for IgA antibodies to Trypanosoma cruzi in congenital infection.
Authors: Di Pentima M C , Edwards M S
Published: May 2017

With the aim of achieving earlier diagnosis of congenital Trypanosoma cruzi infection, we assessed the usefulness of detecting specific IgA antibody by an ELISA. We evaluated 12 pregnant women chronically infected with T. cruzi, their newborn infants, and three additional neonates with parasitemia at birth. The IgA-specific antibody was detected by adapting the procedure for use of a commercial IgG ELISA, the Hemagen Chagas' Kit (Hemagen Diagnostics, Inc., Waltham, MA). Trypanosoma cruzi-specific IgA was detected in 10 (83%) of 12 mothers at delivery, in one of three parasitemic infants, and one of 12 newborns of the chronically infected women. Testing of 13 infants at six months of age revealed IgA in seven infants (54%), of whom four also had persistent T. cruzi-specific IgG. Detection of T. cruzi-specific IgA could provide a criterion for diagnosis of congenital infection in the absence of detectable parasitemia.
Treatment of malarial acute renal failure by hemodialysis.
Authors: Wilairatana P , Westerlund E K , Aursudkij B , Vannaphan S , Krudsood S , Viriyavejakul P , Chokejindachai W , Treeprasertsuk S , Srisuriya P , Gordeuk V R , Brittenham G M , Neild G , Looareesuwan S
Published: May 2017

We studied 112 patients with malarial acute renal failure (ARF) during the period 1991-1997 at Bangkok Hospital for Tropical Diseases (Mahidol University, Bangkok, Thailand). Hemodialysis was performed in 101 (90.2%) of these patients. The mean number of times the patients were hemodialyzed was 6.5 (range = 1-27). Ninety-three (83.0%) patients were oliguric and the remainder were nonoliguric. Patients who had oliguric renal failure required more hemodialyses and had more complications than the nonoliguric patients. The oliguric patients had an eight-fold higher risk of requiring six or more hemodialyses (95% confidence interval = 1.2-53.9, P = 0.0008). The overall mortality rate was 10.7% (12 of 112). Eleven of the patients who died were jaundiced and eight of them had cerebral malaria with a Glasgow Coma Score < or = 8. We conclude that hemodialysis is a useful treatment for oliguric and nonoliguric ARF from severe malaria, particularly when initiated early in the course of the illness.
Prevalence of intestinal parasite infections with special reference to Entamoeba histolytica on the island of Bioko (Equatorial Guinea).
Authors: Roche J , Benito A
Published: May 2017

The prevalence of intestinal parasitic infections was assessed (1993 through 1995) among two different groups of persons on the island of Bioko, Equatorial Guinea. In the first group, parasitologic examinations were performed on stool specimens from a household-based sample of 557 dwellers from the rural area of the island. In the second group, 1,633 inpatients and outpatients at the General Hospital of Malabo (the capital of the country) were studied. All age groups were represented in both groups. The average prevalence of the most common protozoan and helminthic intestinal infections in rural and urban areas, respectively, was as follows: Entamoeba histolytica/E. dispar (14.9% and 32.7%, respectively), Giardia lamblia (7.2% and 8.6%), Ascaris lumbricoides (45.8% and 31.4%), and Trichuris trichiura (25.7% and 36.4%). Seventy-nine sera from patients with amebic liver abscess (suspected by ultrasonography) were studied by an immunohemagglutination assay, with 44 (56%) showing anti-E. histolytica titers > or = 1:32. Of these 79 sera, 71 were studied by an enzyme immunoassay, 86% of which were positive with titers > or = 1:64. This study showed that parasitic infections in Equatorial Guinea represent a major health problem.
Mortality due to schistosomiasis mansoni: a field study in Sudan.
Authors: Kheir M M , Eltoum I A , Saad A M , Ali M M , Baraka O Z , Homeida M M
Published: May 2017

Although schistosomiasis affects 200 million persons, 20 million of whom have advanced disease, little is known about the mortality pattern in areas of endemic schistosomiasis mansoni. In an attempt to assess the mortality rates in an endemic area in Sudan, we conducted two demographic surveys in a village in the Gezira area. Clinical, sonographic, and parasitologic examinations were performed in a randomly selected sample of 25% of the population in 1987 and 1994. One of us asked each head of household about the names, sex, and age of family members. Particularly, we asked about death in the family if any, history of schistosomiasis, abdominal swelling, and hematemesis. Possible causes of death were ascertained by reviewing medical records in the village dispensary and the district hospital. There were 42 deaths in the village. Four males died of hematemesis secondary to portal fibrosis. The crude mortality rate of schistosomiasis was is 51/100,000/year. The overall schistosomiasis fatality rate per year was 1/1,000 infected persons, but was as high as 11/100/infected patients with bleeding varices. These findings showed the impact of schistosomiasis on public health in this economically important region of Sudan.
Congenital transmission of Schistosoma japonicum in pigs.
Authors: Willingham A L , Johansen M V , BÃ¸gh H O , Ito A , Andreassen J , Lindberg R , Christensen N O , Nansen P
Published: May 2017

Congenital transmission of Schistosoma japonicum in pigs was investigated by experimentally infecting sows at four weeks gestation (n = 3), 10 weeks gestation (n = 3), or a few weeks prior to insemination (n = 2). None of the piglets born to sows infected prior to insemination or in early pregnancy were found to be infected. However, all of the piglets (n = 26) born to sows infected at 10 weeks gestation were found to harbor schistosomes with S. japonicum eggs recovered from both their feces and livers. The findings show that congenital S. japonicum infection of pigs can occur if sows are infected during mid-to-late pregnancy and may have important implications not only for pigs but also for other mammalian hosts of schistosomes, including humans.
Replication of dengue type 2 virus in Culex quinquefasciatus (Diptera: Culicidae).
Authors: Vazeille-Falcoz M , Rosen L , Mousson L , Rodhain F
Published: May 2017

We were able to infect Culex quinquefasciatus by the parenteral route with dengue virus type 2. The percentage of mosquitoes infected was dose dependent and we obtained a rate of 45.6% infected Cx. quinquefasciatus when a 10(5.9) MID50 (mosquito infectious dose for 50% of the individuals as measured in Aedes aegypti) of dengue virus type 2 per mosquito was used. Infection was detected by an immunofluorescent assay performed on mosquito head squashes 14 days after infection. The replication of dengue virus in Cx. quinquefasciatus was either at a very low level of magnitude or generated a large number of noninfectious particles since the triturated bodies of infected Cx. quinquefasciatus did not infect Ae. aegypti mosquitoes when inoculated parenterally. We were unable to infect Cx. quinquefasciatus females orally with an artificial meal that infected 100% of Ae. aegypti females. These findings lead us to agree with the consensus that Cx. quinquefasciatus should not be considered a biological vector of dengue viruses.
Population structure of the primary malaria vector in South America, Anopheles darlingi, using isozyme, random amplified polymorphic DNA, internal transcribed spacer 2, and morphologic markers.
Authors: Manguin S , Wilkerson R C , Conn J E , Rubio-Palis Y , Danoff-Burg J A , Roberts D R
Published: May 2017

A genetic and morphologic survey of Anopheles darlingi populations collected from seven countries in Central and South America was performed to clarify the taxonomic status of this major malaria vector species in the Americas. Population genetics was based on three techniques including isozyme, random amplified polymorphic DNA-polymerase chain reaction (RAPD-PCR), and internal transcribed spacer 2 (ITS2) markers. The results of the isozyme analysis indicated moderate differences in the allele frequencies of three putative loci (glutamate oxalaoacetate transaminase-1, isocitrate dehydrogenase-1, and phosphoglucomutase) of the 31 analyzed. No fixed electromorphic differences separated the populations of An. darlingi, which showed little genetic divergence (Nei distances = 0.976-0.995). Fragments produced by RAPD-PCR demonstrated evidence of geographic partitioning and showed that all populations were separated by small genetic distances as measured with the 1 - S distance matrix. The ITS2 sequences for all samples were identical except for four individuals from Belize that differed by a three-base deletion (CCC). The morphologic study demonstrated that the Euclidean distances ranged from 0.02 to 0.14, with the highest value observed between populations from Belize and Bolivia. Based on these analyses, all the An. darlingi populations examined demonstrated a genetic similarity that is consistent with the existence of a single species and suggest that gene flow is occurring throughout the species' geographic range.
Reliability of parental history of antibiotic use for Filipino children admitted with acute lower respiratory tract infection.
Authors: Sombrero L , Sunico M E , Quiambao B , Lucero M , Gatchalian S , Leinonen M , Ruutu P
Published: May 2017

Parental history on antibiotic use and the urine antibacterial assay (UABA) result were compared in a study on Filipino children with acute lower respiratory tract infection (ALRI). Among 108 patients in whom urine for the UABA could be collected prior to starting antibiotic treatment in the hospital, 59 (55%) guardians reported preceding antibiotic use, 54% of whom were positive in the UABA. In another 37 (34%), the UABA result was positive, indicating nonreported use of antibiotics. Among 190 patients in whom urine could be collected only after intravenous administration of antibiotic, the UABA demonstrated large inhibition zones after the first dose in most patients but a negative result was seen in 14 cases. The inhibition zone radius was significantly smaller for chloramphenicol than for beta-lactam antibiotics (8.3 mm versus 16.1 mm after one dose; 95% confidence intervals = 7.0-9.7 and 14.9-17.2, respectively). Parental history on antibiotic use gives an underestimate of preceding antibiotic use in children with ALRI in the Philippines. The result partly explains the low yield of blood culture in many studies on ALRI, and stresses the need to develop new diagnostic methods not based on culture for those organisms highly sensitive to antibiotics such as Streptococcus pneumoniae and Haemophilus influenzae.
Epidemiology of Burkholderia pseudomallei in Thailand.
Authors: Vuddhakul V , Tharavichitkul P , Na-Ngam N , Jitsurong S , Kunthawa B , Noimay P , Binla A , Thamlikitkul V
Published: May 2017

The distribution of Burkholderia pseudomallei in soil collected from four regions of Thailand and the frequency of B. pseudomallei infections in patients attending government hospitals throughout Thailand in 1997 were surveyed. A total of 3,585 soil samples collected from 896 sites in four regions of Thailand were cultured for B. pseudomallei using selective enrichment broth and modified Ashdown's agar. The organism was recovered in 4.4%, 6.1%, 20.4%, and 5.9% of the soil samples collected from the northern, central, northeastern, and southern regions, respectively, of Thailand (P < 0.0001). Burkholderia pseudomallei was cultured from 50.1% of the sites in the northeastern region compared with 13.8%, 24.5%, and 18.4% in the northern, central, and southern regions, respectively (P < 0.0001). The infection rate in patients attending government hospitals in the northeastern region (137.9 per 100,000 inpatients) was significantly higher than those in the northern (18 per 100,000 inpatients), central (13.4 per 100,000 inpatients), and southern (14.4 per 100,000 inpatients) regions, respectively (P < 0.0001). It is suggested that melioidosis, which is endemic in Thailand, is associated with the presence of B. pseudomallei in soil.
Relationships between several markers of extracellular matrix turn-over and ultrasonography in human Schistosomiasis mansoni.
Authors: Ricard-Blum S , Hartmann D J , Grenard P , Ravaoalimalala V E , Boisier P , Esterre P
Published: May 2017

We measured the concentrations of several serum and urinary fibrosis markers, which are metabolites of extracellular matrix, in schistosomiasis patients to investigate their relationship with the ultrasonographic scoring system and with parasitologic data. This study was conducted in patients with various stages of the disease evaluated by ultrasonography (intestinal disease with no organ involvement, with minor hepatosplenic involvement and with severe disease) and in endemic controls. The level of hyaluronan, which were increased in infected patients compared with controls (P < 0.01), was the only fibrosis marker that correlated with the ultrasonographic score (P = 0.003) and is thus a potential serum marker of schistosomiasis-associated morbidity. Urinary free pyridinoline levels were lower (P < 0.001) in infected patients with fibrosis (score > or = 1) than in nonfibrotic patients. A two-year follow-up of the patients treated with praziquantel showed that type I collagen and hyaluronan decreased during the first year post-treatment, whereas free pyridinolines peaked after 12 months and decreased thereafter.
Decreased seroprevalence for Toxoplasma gondii in Seventh Day Adventists in Maryland.
Authors: Roghmann M C , Faulkner C T , Lefkowitz A , Patton S , Zimmerman J , Morris J G
Published: May 2017

Despite its widespread prevalence, uncertainties remain about the relative contribution of various routes of transmission to the overall rate of infection with Toxoplasma gondii, particularly in developed countries. To explore the hypothesis that meat consumption is an important risk factor for infection, a cross-sectional seroprevalence study was performed on healthy adults in one region in the state of Maryland. The population included Seventh Day Adventists who as a group follow a diet containing no meat, and control community volunteers who were not Seventh Day Adventists. Thirty-one percent of the population had serologic evidence of T. gondii infection. People with T. gondii infection were older (49 versus 42 years old; P < 0.01, by t-test) and less likely to be Seventh Day Adventists (24% versus 50%; P < 0.01, by chi-square test) than people without T. gondii infection. When adjustments were made for age and gender through multiple logistic regression, Seventh Day Adventists had a significantly decreased risk of T. gondii infection (odds ratio = 0.21, 95% confidence interval = 0.09-0.46, P = 0.0001) compared with the controls. While the basis for this effect remains to be determined, one possible protective factor is the general adherence of Seventh Day Adventists to a diet that does not contain meat.
Risk factors for infection with Toxoplasma gondii for residents and workers on swine farms in Illinois.
Authors: Weigel R M , Dubey J P , Dyer D , Siegel A M
Published: May 2017

Risk factors for Toxoplasma gondii infection in workers and residents of swine farms were studied on 43 farms in Illinois. Blood samples were collected from 174 adults in 1993. The T. gondii seroprevalence was 31%. An interview was conducted with each participant, obtaining information on demographic characteristics and behaviors suspected to affect the risk of T. gondii infection. Factors associated with increased risk of T. gondii seropositivity were a higher number of seropositive cats trapped on the farm, male sex, rearing pigs on pasture, and gardening. Factors associated with a decreased risk were handling of pig feed and presence of cats inside the pig facilities. Thus, infection of cats with T. gondii increased the risk of human infection, and contact with soil was a likely mechanism for transmission. The increased risk of seropositivity in males is attributed to less attention paid to cleanliness in food preparation and eating.
Seroepidemiology of schistosomiasis in Puerto Rico: evidence for vanishing endemicity.
Authors: Hillyer G V , Soler de Galanes M
Published: May 2017

The current study summarizes our findings of anti-schistosome egg antibody by the circumoval precipitin test for two different populations in Puerto Rico. One group, exclusively males more than 40 years of age and from all municipalities on the island, was from the Veterans Administration Hospital for the period 1988-1997. The second group resided southeast of San Juan, around the municipality of Caguas and adjacent municipalities east of Caguas, was of both sexes and mostly until 1997 of undetermined ages for the period 1993-1997. Results reveal a yearly decrease in testing requests from the Veterans Administration Hospital from 148 in 1988 and 1989 with 16% positive to three in 1996 through 1998 with none positive. This decrease in testing requests was because of a decrease of suspicion of schistosomiasis in this group. The other patient population from the Caguas region showed a gradual but continuous decrease in seropositive individuals from 21% in 1993 to 12% in 1996, with precipitous decrease to 5% in 1997 and only 1% in 1998. Moreover, there were four patients from which at least two serum samples were obtained one or two years apart and tested. In each instance the more recently obtained sample had lower antibody reactions than the first as reflected in lower percentages of positive egg reactors. The fact that they were treated with praziquantel after the first testing also suggests that the infected population was being eliminated through chemotherapy. These combined results suggest the elimination of infections with Schistosoma mansoni in the traditionally high prevalence regions east of San Juan in the absence of any proactive control efforts in Puerto Rico. Because of the rapid urbanizing of Puerto Rico, the one identifiable control effort is economic development and well being.
Necator americanus (human hookworm) aspartyl proteinases and digestion of skin macromolecules during skin penetration.
Authors: Brown A , Girod N , Billett E E , Pritchard D I
Published: May 2017

The infective larvae of Necator americanus were shown to secrete all mechanistic classes of proteolytic enzymes with two overall pH optima of 6.5 and 8.5 using fluorescein isothiocyanate-labeled casein as the substrate. Since infective larvae are obligate skin penetrators, the effect of each of these enzyme classes against macromolecules derived from human skin was examined. Larval secretions were shown to degrade collagen types I, III, IV, and V, fibronectin, laminin, and elastin. All the skin macromolecules tested were hydrolyzed by aspartyl proteinase activity, which was inhibitable by pepstatin A. Collagen and elastin was also hydrolyzed by metalloproteinase activity, while the serine proteinase activity hydrolyzed only elastin. As a consequence of these experiments, the effect of proteinase inhibitors on the penetration of live larvae through hamster skin was tested. Larval penetration was significantly inhibited only by pepstatin A, confirming the importance of the aspartyl proteinase activity during the skin penetration process.
Long-term persistence of cellular hyporesponsiveness to filarial antigens after clearance of microfilaremia.
Authors: Gopinath R , Hanna L E , Kumaraswami V , Pillai S V , Kavitha V , Vijayasekaran V , Rajasekharan A , Nutman T B
Published: May 2017

The persistence of parasite-specific cellular hyporesponsiveness after clearance of blood microfilariae (mf) was studied in 18 individuals who had been treated with a single dose of ivermectin, diethylcarbamazine, or a combination 2-3 years previously and who had initially cleared their parasitemia. At recruitment into the present study, 50% were again mf+ and 50% remained mf-. There were no significant differences between the mf+ and mf- groups in the amount of interferon-gamma (IFN-gamma) produced by peripheral blood mononuclear cells in response to adult or microfilarial antigens, although IFN-gamma production in response to purified protein derivative was greater in the mf+ group (geometric mean [gm] = 3,791 pg/ml; P = 0.02) than in the mf- group (gm = 600 pg/ml). These data suggest that although microfilaremic individuals may temporarily regain the ability to produce IFN-gamma to parasite antigens post-treatment, they subsequently revert to a state of hyporesponsiveness to mf-containing antigens that appears to be independent of the recurrence of microfilaremia and the response to nonparasite antigens.
Imported African tick bite fever: a case report.
Authors: Sexton D J , Corey G R , Greenfield J C , Burton C S , Raoult D
Published: May 2017

We describe a patient with African tick-bite fever who acquired his infection while visiting rural areas of South Africa and then became sick after returning to the United States. The dominant clinical feature of his illness was the presence of multiple, ulcerated lesions (tache noires). Physicians in the United States and other non-African countries who see travelers returning from southern parts of Africa who give a history of recent tick bite and/or present with multiple, crusted or vesicular skin lesions should be alert to this diagnosis and institute treatment with doxycycline.
Diarrheal disease in patients infected with human immunodeficiency virus in Bangkok, Thailand.
Authors: Wanke C A , Cohan D , Thummakul T , Jongwuitiwes S , Grayson M L , Hammer S M , Hanvanich M
Published: May 2017

Diarrheal disease and its associated morbidities occur frequently in patients infected with human immunodeficiency virus (HIV) and may be associated with a decreased quality of life. We studied the spectrum of symptoms, measures of nutritional status, and the enteric pathogens associated with diarrheal disease in a group of 24 patients infected with HIV in Bangkok, Thailand compared with a group of 19 patients infected with HIV without diarrhea cared for at the same clinic. Patients with diarrhea appeared to have more advanced disease by CD4 cell counts and complained more frequently of symptoms such as anorexia, gas, and bloating than patients without diarrhea. Patients with diarrhea had a tendency toward a lower nutritional status, as measured by body mass index and mid arm circumference. Stool culture and examination revealed that enteric pathogens including Salmonella species and Cryptosporidium parvum sporidia were recovered at equal frequencies in patients with and without diarrhea (27% of the patients with diarrhea and 25% of the patients without diarrhea). Microsporidia was identified in one patient with diarrhea. It was not possible to identify a pathogen in 73% of the patients with diarrhea and 75% of the patients without diarrhea, suggesting that additional agents or factors may be responsible for the diarrheal symptoms in the patients with diarrhea. More extensive studies to identify potentially treatable pathogens in HIV-infected patients with diarrhea in Thailand are warranted and further attempts to better define the syndrome of pathogen-negative diarrheal disease in patients infected with HIV might result in the development of more targeted interventions in these patients.
Leiomyosarcoma of the esophagus in a patient with chagasic megaesophagus: case report and literature review.
Authors: Adad S J , Etchebehere R M , Hayashi E M , Asai R K , de Souza Fernandes P , Macedo C F , Crema E
Published: May 2017

Leiomyosarcoma constitutes approximately 0.5% of the malignant neoplasias of the esophagus and its association with megaesophagus has not been described. We report on a case of a woman with dysphagia that was slowly progressive from the age of 19 due to chagasic megaesophagus. The woman was subjected to cardiomyotomy at the age of 49. She presented a rapid worsening of the dysphagia due to leiomyosarcoma at the age of 61, and was subjected to subtotal esophagectomy with cervical esophagogastroplasty. She developed pulmonary and hepatic metastases 14 months after surgery and died six months later.
Evidence for a long-term effect of a single dose of praziquantel on Schistosoma mansoni-induced hepatosplenic lesions in northern Uganda.
Authors: Frenzel K , Grigull L , Odongo-Aginya E , Ndugwa C M , Loroni-Lakwo T , Schweigmann U , Vester U , Spannbrucker N , Doehring E
Published: May 2017

Treatment with praziquantel reduces the prevalence and intensity of Schistosoma mansoni infection. However, reversibility of periportal fibrosis of the liver, which potentially leads to fatal complications, is not unequivocally substantiated. In the Nile District of Uganda, 460 patients were parasitologically (Kato-Katz method) and ultrasonographically examined during October 1991, October 1992, and May 1994. Treatment with praziquantel at a dosage of 40 mg per kilogram of body weight was given in October 1991 and October 1992 to 460 individuals (group A). Another 192 patients were seen during the baseline study in October 1991 and missed the follow-up in October 1992 but took part in the second follow-up in May 1994. Thus, they received praziquantel only once in October 1991 (group B) and had an interval of 2.7 years until the next investigation in May 1994. Periportal thickening (PT) of the liver was assessed by ultrasound at each time point. Praziquantel therapy reduced the prevalence of S. mansoni in group A from 84% in 1991 to 31% in 1992 and 30% in 1994. The respective intensities of infection (geometric means of egg output) were 81 eggs per gram (epg) of stool in 1991, 31 epg in 1992, and 30 epg in 1994. Periportal thickening was found in 46% of patients in 1991, 32% of patients in 1992, and 35% of patients in 1994. Reversibility of PT was influenced by age (markedly lower reversibility in individuals older than 30 years) and sex (women and girls responded less favorably than did men and boys). Surprisingly, no significant difference was detected between group A and group B with respect to reversibility of PT The outcome between the 2 groups did not differ significantly. This may indicate that a single dose of praziquantel (as given to group B) may have a longer lasting effect than previously thought, that is, more than 2.5 years.
Short report: microsatellite sequences as markers for population genetic studies of the mosquito Aedes aegypti, the vector of dengue viruses.
Authors: Huber K , Mousson L , Rodhain F , Failloux A B
Published: May 2017

We report the isolation of microsatellites from an enriched library of genomic repeated sequences, using a biotin-labeled oligonucleotide bound to streptavidin-coated magnetic particles. Four microsatellites were obtained from a partial library of 120 recombinant clones. This more efficient and rapid method to obtain these specific repeated sequences is preferred to the conventional isolation procedure based on the construction of a genomic library. Microsatellite markers would be promising molecular tools for the study of genetic variability of mosquito populations. Analyses of genetic structure and gene flow would provide information on the distance, direction and rate of dispersal of genes in Aedes aegypti populations. Knowledge on gene dispersal patterns is required to develop vector control strategies.
Spatial distribution and habitat characterization of anopheline mosquito larvae in Western Kenya.
Authors: Minakawa N , Mutero C M , Githure J I , Beier J C , Yan G
Published: May 2017

Studies were conducted to characterize larval habitats of anopheline mosquitoes and to analyze spatial heterogeneity of mosquito species in the Suba District of western Kenya. A total of 128 aquatic habitats containing mosquito larvae were sampled, and 2,209 anopheline and 10,538 culicine larvae were collected. The habitats were characterized based on size, pH, distance to the nearest house and to the shore of Lake Victoria, coverage of canopy, surface debris, algae and emergent plants, turbidity, substrate, and habitat types. Microscopic identification of third- and fourth-instar anopheline larvae did not yield any Anopheles funestus or other anophelines. A total of 829 An. gambiae s.l. larvae from all habitats were analyzed further by rDNA-polymerase chain reaction to identify individual species within the An. gambiae species complex. Overall, An. arabiensis was the predominant species (63.4%), and An. gambiae was less common (31.4%). The species composition of An. gambiae s.l. varied significantly among the sampling sites throughout Suba District. The larval habitats in the southern area of the district had a higher proportion of An. gambiae than in the northern area. Multiple logistic analysis did not detect any significant association between the occurrence of anopheline larvae and habitat variables, and principal component analysis did not identify key environmental factors associated with the abundance of An. gambiae. However, significant spatial heterogeneity in the relative abundance of An. gambiae within the Suba district was detected. When the effect of larval habitat locality was considered in the analysis, we found that the distance to the nearest house and substrate type were significantly associated with the relative abundance of An. gambiae. Future studies integrating detailed water chemistry analysis, remote sensing technology, and the ecology of predators may be required to further elucidate the mechanisms underlying the observed spatial variation of anopheline larval distribution.
In vitro activity of dihydroartemisinin against clinical isolates of Plasmodium falciparum in Yaounde, Cameroon.
Authors: Ringwald P , Bickii J , Basco L K
Published: May 2017

The in vitro activities of dihydroartemisinin (the biologically active metabolite of artemisinin derivatives), chloroquine, monodesethylamodiaquine (the biologically active metabolite of amodiaquine), quinine, mefloquine, halofantrine, and pyrimethamine were assessed in 65 African isolates of Plasmodium falciparum from Yaounde, Cameroon using an isotopic microtest. The 50% inhibitory concentration (IC50) values for dihydroartemisinin were within a narrow range from 0.25 to 4.56 nM, with a geometric mean of 1.11 nM (95% confidence interval = 0.96-1.28 nM). Dihydroartemisinin was equally active (P > 0.05) against the chloroquine-sensitive isolates (geometric mean IC50 = 1.25 nM, 95% confidence interval = 0.99-1.57 nM) and the chloroquine-resistant isolates (geometric mean IC50 = 0.979 nM, 95% confidence interval = 0.816-1.18 nM). A significant positive correlation was observed between the responses to dihydroartemisinin and mefloquine (r = 0.662) or halofantrine (r = 0.284), suggesting in vitro cross-resistance. There was no correlation between the responses to dihydroartemisinin and other antimalarial drugs.
Mitochondrial DNA variation among Anopheles albimanus populations.
Authors: De Merida A M , Palmieri M , Yurrita M , Molina A , Molina E , Black W C
Published: May 2017

Barriers to gene flow between Pacific and Atlantic coast populations of Anopheles albimanus were reported in an earlier study of variation in the intergenic spacer of the nuclear ribosomal DNA. We examined the distribution of mitochondrial DNA haplotypes among A. albimanus populations to test for gene flow barriers with an independent genetic marker. A region of the NADH dehydrogenase subunit 5 gene was amplified by the polymerase chain reaction (PCR) in 1,105 mosquitoes collected from 16 locations in Guatemala and in single collections from Mexico, Honduras, Nicaragua, Costa Rica, Panama, Colombia, and Venezuela. The PCR products were tested for variation using single strand conformation polymorphism analysis and 45 haplotypes were detected. Haplotype frequencies did not vary between coasts in Guatemala. Populations within approximately 200 km of one another were panmictic. However, at distances > 200 km, FST and geographic distances were correlated suggesting that populations are isolated by distance.