bluuebunny/crossref_metadata_2025 huggingface dataset:
Hepatic capillariasis in children: report of 3 cases in Brazil.
Authors: Sawamura R , Fernandes M I , Peres L C , GalvÃ£o L C , Goldani H A , Jorge S M , de Melo Rocha G , de Souza N M
Published: May 2017

Capillaria hepatica is a helminth that may cause an extremely rare condition of parasitic hepatitis. Only 29 cases have been published, 2 of them in Brazil. We report here 3 cases of children in Brazil with massive hepatic capillariasis who presented the characteristic triad of this type of infection, i.e., persistent fever, hepatomegaly, and eosinophilia. The diagnosis was made by liver biopsy. All children responded well after treatment with thiabendazole (case 1), albendazole (case 3), and albendazole in combination with a corticoid (case 2). Case 1 has been followed-up for 24 years, an event not previously reported in the literature.
Short report: improved diagnosis and follow-up of canine leishmaniasis using amastigote-based indirect immunofluorescence.
Authors: FernÃ¡ndez-PÃ©rez F J , MÃ©ndez S , de la Fuente C , GÃ³mez-MuÃ±oz M T , Cuquerella M , Alunda J M
Published: May 2017

A comparison of an indirect immunofluorescence test using promastigotes (IFATp) or cultured amastigotes (IFATa) in the diagnosis and follow-up of canine leishmaniasis caused by Leishmania infantum was carried out. Results obtained with both diagnostic methods were in good agreement although the IFATa titration was more sensitive than the currently used IFATp without losing specificity. The higher sensitivity of the amastigote-based IFAT resulted in an earlier diagnosis in the absence of clinical signs. Both methods showed comparable results for monitoring the clinical evolution of naturally infected and treated (meglumine antimoniate plus allopurinol) dogs.
Production of a high level of specific IgG4 antibody associated with resistance to albendazole treatment in HLA-DRB1*0901-positive patients with strongyloidiasis.
Authors: Satoh M , Toma H , Sato Y , Kikuchi M , Takara M , Shiroma Y , Kiyuna S , Hirayama K
Published: May 2017

Strongyloidiasis, a human intestinal infection with Strongyloides stercoralis, is difficult to treat with drugs. The factors influencing this phenomenon remain unclear. To determine the host factors involved in response to treatment, 46 patients with strongyloidiasis were treated with albendazole, followed-up for 1 year, and separated into two groups: cured and non-cured. Serum levels of specific IgA, IgE, IgG, IgG1, and IgG4 antibodies were estimated using S. stercoralis antigen. Significantly higher titers of IgG4 antibody were observed in the non-cured group than in the cured group (P = 0.016). A total of 88 patients were typed for HLA-DRB1 alleles and analyzed for serum levels of antibody. The S. stercoralis-specific IgG4 antibody titers were significantly higher in the HLA-DRB1*0901-positive group than in the negative group (corrected P = 0.044). These results suggest that HLA-DRB1*0901 is a possible genetic marker for resistance to treatment of S. stercoralis that is associated with elevation of S. stercoralis-specific IgG4 antibody titer.
The American Society of Tropical Medicine and Hygiene initiative to stimulate educational programs to enhance medical expertise in tropical diseases.
Authors: Barry M , Maguire J H , Weller P F
Published: May 2017

More than a decade ago, at a time when current and emerging tropical diseases posed growing threats to the United States, expert panels convened by the Institute of Medicine of the U.S. National Academy of Sciences concluded that medical expertise within the United States competent to address diseases of the tropics had declined. Recognizing a national need to encourage and enhance such, The American Society of Tropical Medicine and Hygiene developed a program to stimulate new postgraduate medical education in diseases of the tropics. The Society formally requested academic institutions within the United States and Canada to propose new postgraduate programs. To assure the quality of these new curricular offerings, the Society developed an outline of key areas of competency and agreed to offer an examination that would grant physicians a Certificate of Knowledge in Clinical Tropical Medicine and Travelers Health. The certifying examination was to be an integral component of a program to stimulate academic institutions to provide instructional programs in tropical diseases and to encourage physicians to become trained, evaluated, and recognized for their knowledge of clinical tropical diseases and travelers' health. The Society's initiative to stimulate educational programs in tropical medicine is reviewed.
Detection of dengue virus RNA by reverse transcription-polymerase chain reaction in the liver and lymphoid organs but not in the brain in fatal human infection.
Authors: Rosen L , Drouet M T , Deubel V
Published: May 2017

Autopsy tissues from 18 children believed to have died of dengue hemorrhagic fever were tested for the presence of dengue virus RNA by reverse transcription-polymerase chain reaction (RT-PCR). Such RNA was found in 14 of 18 liver specimens, 13 of 18 spleen specimens and 7 of 16 mesenteric lymph node specimens. No dengue virus RNA was detected in 44 samples of brain tissue from 15 individuals, 1 or more of whose other tissues yielded such RNA. All tissues had been tested previously for dengue virus by mosquito inoculation. In those tests, virus was recovered from 5 of 18 liver and 2 of 18 spleen specimens. Thus, the RT-PCR is more sensitive than the most sensitive virus isolation technique for detecting dengue virus or its components in human tissue. Failure to isolate virus from most of spleen and all mesenteric lymph node specimens may indicate that those tissues contained primarily degraded virus undergoing inactivation.
Common occurrence of concurrent infections by multiple dengue virus serotypes.
Authors: LoroÃ±o-Pino M A , Cropp C B , FarfÃ¡n J A , Vorndam A V , RodrÃ­guez-Angulo E M , Rosado-Paredes E P , Flores-Flores L F , Beaty B J , Gubler D J
Published: May 2017

The co-circulation of all 4 dengue virus serotypes in the same community, common since the 1950s in Southeast Asia, has now become a frequent occurrence in many Caribbean Islands, Mexico, and Central and South America in the past 20 years. As a consequence, the frequency of concurrent infections would be expected to increase in these areas. To assess this, using state of the art technology, we screened viremic serum samples and mosquitoes inoculated with serum samples collected during epidemics involving multiple dengue virus serotypes in Indonesia, Mexico, and Puerto Rico for virus isolation. Of 292 samples tested, 16 (5.5%) were found to contain 2 or more dengue viruses by an indirect immunofluorescence test and/or the reverse transcriptase-polymerase chain reaction.
Short report: evaluation of a monoclonal antibody-based latex agglutination test for rapid diagnosis of septicemic melioidosis.
Authors: Samosornsuk N , Lulitanond A , Saenla N , Anuntagool N , Wongratanacheewin S , Sirisinha S
Published: May 2017

A monoclonal antibody (MAb)-based latex agglutination (MAb-LA) test was developed to rapidly identify Burkholderia pseudomallei in hemoculture of patients with septicemic melioidosis. The method was evaluated in a clinical situation on 396 hemocultures positive for bacterial growth, of which 75 cultures were positive for B. pseudomallei by conventional biochemical tests. The sensitivity and specificity of the MAb-LA test were 95% and 100%, respectively. The positive and negative predictive values were 100% and 99%. The method is highly reliable and suitable for rapid diagnosis of septicemic melioidosis, reducing the time normally required from a minimum of 3-4 days by conventional methods to less than 30 hr. Most of these 30 hr are involved in growing up enough bacteria to perform the MAb-LA test, which itself takes only 1 min.
Impact of the crayfish Procambarus clarkii on Schistosoma haematobium transmission in Kenya.
Authors: Mkoji G M , Hofkin B V , Kuris A M , Stewart-Oaten A , Mungai B N , Kihara J H , Mungai F , Yundu J , Mbui J , Rashid J R , Kariuki C H , Ouma J H , Koech D K , Loker E S
Published: May 2017

The Louisiana red swamp crayfish, Procambarus clarkii, which was introduced into east Africa in the 1950s or 1960s, has since widely dispersed. Previous work by our group has shown that P. clarkii can reduce populations of the molluscan intermediate hosts of human schistosomes through predatory and competitive interactions. Here, we investigate whether crayfish can reduce populations of Bulinus africanus and consequently, Schistosoma haematobium prevalence in school children. Children from 6 primary schools in the Machakos and Kitui Districts of Kenya were selected for study. Schools were divided into 3 experimental-control pairs. At experimental schools, crayfish were introduced into nearby aquatic habitats harboring Bulinus africanus snails and serving as S. haematobium transmission sites. Snail habitats near control schools did not receive crayfish. Six months after crayfish introduction, all infected children were treated with praziquantel. Children were then monitored quarterly for 2 years, at which time infection and reinfection rates were compared statistically between the paired schools. In one such pair, crayfish failed to establish, resulting in neither snail control nor a reduction in transmission. At the second pair of schools, the numbers of snails were decreased by the presence of crayfish, but a clear difference in infection rates in children could not be detected, primarily because drought conditions kept overall transmission rates low. At the third school pair, crayfish established well in experimental habitats, snail numbers decreased precipitously, and children at the experimental school were significantly less likely to acquire S. haematobium infections than children at the control school. Our results indicate that under certain environmental circumstances, P. clarkii exerts a significant impact on the transmission of human schistosomiasis in Kenya. Important questions remain regarding the impact of P. clarkii on Kenyan freshwater ecosystems, not the least of which is its potential to significantly influence the epidemiology of schistosomiasis in east Africa.
Anti-malarial drug use among preschool children in an area of seasonal malaria transmission in Kenya.
Authors: Verhoef H , Hodgins E , Eggelte T A , Carter J Y , Lema O , West C E , Kok F J
Published: May 2017

The aims of this study were to estimate the proportion of asymptomatic Kenyan preschool children using anti-malarial drugs, to identify factors associated with chloroquine use, and to assess the validity of frequency of febrile episodes and drug use reported by mothers or carers. Of 318 children studied, 38% (95% confidence interval [CI] = 30-47%]) tested positive for chloroquine or sulfadoxine. Of chloroquine-positive children, 15% had concentrations exceeding the estimated minimum therapeutically effective values. Among those testing negative for sulfadoxine, chloroquine-positive children were more frequently parasitemic (odds ratio = 2.6, 95% CI = 1.3-5.2), and had lower mean hemoglobin concentrations (6.1 g/L, 95% CI = 2.1-10.1) than chloroquine-negative children. Mothers over-reported the frequency of malaria or fever episodes as usually defined in medical studies, and underreported anti-malarial drug use. We conclude that anti-malarials are frequently given for treatment of malaria or malaria-associated illness, rather than prophylactically or for symptoms unrelated to malaria. Questionnaire surveys cannot replace biochemical markers to obtain information on anti-malarial drug use.
Safety, immunogenicity, and lot stability of the whole cell/recombinant B subunit (WC/rCTB) cholera vaccine in Peruvian adults and children.
Authors: Taylor D N , CÃ¡rdenas V , Perez J , Puga R , Svennerholm A M
Published: May 2017

To assess the safety, immunogenicity, and lot stability of the whole cell/recombinant B subunit cholera vaccine, 2 lots manufactured in June 1991 and February 1992 were tested in January 1995. Two oral doses of vaccine or placebo given 2 weeks apart were given with buffer to 216 Peruvian adults and children. Symptoms were elicited for 3 days after each dose. Serum and plasma specimens obtained from each volunteer before vaccination and 10-14 days after the second dose were tested for vibriocidal and anti-cholera toxin antibodies. The vaccine was well-tolerated. Nearly half of the 100 vaccinees had pre-vaccination vibriocidal titers > or = 1:40. Elevated titers were observed in 22% of 37 children 2-5 years of age compared with 66% of 63 vaccinees 6-65 years (P < 0.001). A > or =2-fold serum vibriocidal response was observed in 55% of 100 vaccinees and 6% of 32 placebo recipients. An elevated pre-vaccination titer (< or =1:40) did not change the proportion of vaccinees who responded with a > or =2-fold increase in vibriocidal titer (51% versus 59%, difference not significant), but did change the proportion responding with a > or =4-fold increase (41% versus 22%; P < 0.05). The vibriocidal seroconversion rate was lowest in children 2-5 years old despite low pre-vaccination titers. Two-fold or greater serum antitoxic responses in IgA and IgG were observed in >90% of the vaccinees; > or =4-fold responses were seen in 65-70% of the vaccinees with a 6-8-fold increase over baseline. Plasma specimens were as good as sera for determining anti-toxic antibodies by ELISA, but were less satisfactory for determining vibriocidal antibody titers.
An accelerated schedule for tick-borne encephalitis vaccine: the American Military experience in Bosnia.
Authors: Craig S C , Pittman P R , Lewis T E , Rossi C A , Henchal E A , Kuschner R A , Martinez C , Kohlhase K F , Cuthie J C , Welch G E , Sanchez J L
Published: May 2017

Tick-borne encephalitis (TBE) is a viral illness endemic to the Balkan region. United States military forces were deployed to Bosnia in early 1996 as part of Operation Joint Endeavor, a U.S.-led multinational peace-keeping operation. To counteract the TBE threat, an inactivated, parenteral vaccine (FSME-Immun Inject; Immuno AG, Vienna, Austria) was offered to soldiers at high risk on a volunteer basis in an accelerated, 3-dose schedule (0, 7, and 28 days). Passive adverse reaction surveillance was conducted on 3,981 vaccinated personnel. Paired sera from a randomly selected group of 1,913 deployed personnel (954 who received vaccine and 959 who were unvaccinated) were tested for antibodies to TBE by an ELISA. Three-dose recipients demonstrated an 80% seroconversion rate (4-fold or greater increase in anti-TBE titers). By comparison, the TBE infection rate in the unvaccinated cohort was found to be only 0.42% (4 of 959). Only 0.18% of vaccinees reported self-limited symptoms. An accelerated immunization schedule appears to be an acceptable option for military personnel or travelers on short-term notice to TBE-endemic areas.
Rabies mass vaccination campaigns in Tunisia: are vaccinated dogs correctly immunized?
Authors: Seghaier C , Cliquet F , Hammami S , Aouina T , Tlatli A , Aubert M
Published: May 2017

Among the 301 dogs vaccinated against rabies in a suburban area of Tunis, 165 were sero-surveyed for 13 months. One month after vaccination, 65% of the dogs less than 1 year of age and 76-84% of the older dogs had significant antibody titers. One month after annual revaccination, these percentages ranged between 92% and 100%. Puppies (less than 3 months old) responded to vaccination with no significant interference by passive maternal immunity. Based on these percentages, a 93% rate of protection may be expected for vaccinated dogs. This study confirms that all dogs (even those less than 3 months of age) must be vaccinated during mass campaigns. The expected protection conferred by locally produced potent vaccines reaches 79-99% based on the age of the dogs. The alleged relative inability of local dogs to respond to vaccination cannot explain the partial success of rabies control in Tunisia.
Shipboard impact of a probable Norwalk virus outbreak from coastal Japan.
Authors: Corwin A L , Soderquist R , Edwards M , White A , Beecham J , Mills P , Larasati R P , Subekti D , Ansari T , Burans J , Oyofo B
Published: May 2017

Norwalk virus has been implicated in shipboard diarrheal disease outbreaks throughout Asia. A large outbreak of suspected Norwalk virus was investigated on a U.S. Naval aircraft carrier following the clinical recognition of 450 cases of gastroenteritis over a 2-week period (September 14-28, 1997) during coastal exercises. A random sampling of 44 cases from 450 personnel who sought medical attention was compared with 19 controls. Junior enlisted sailors and marines comprised 97% of all cases. There was no evidence of shipboard geographic clustering of cases. Furthermore, no single food type was associated with illness on the basis of comparative analysis (cases versus controls). Principal case signs and symptoms reported included watery stools (89%), nausea (82%), and vomiting (77%). Anecdotal reports indicated > 50% of the cases received rehydration therapy. An absence of fever was also noted in 32% of the cases and only 5% had blood in their stools. The mean duration of illness was 37 hr, with a range of 3-96 hr. Laboratory findings based on reverse transcription-polymerase chain reaction and Southern hybridization methods showed that 21 (72%) of 29 patients had evidence of the UK2 prototype of the Norwalk virus. A cross-sectional study of 131 crew members from the ships population (n = 4,200) showed an attack rate of 44%. Attack rate is a variant of an incident rate applied to a narrowly defined population observed for a limited period of time, such as during an outbreak. The numerator is people who get sick and the denominator is people (population) at risk. An extrapolation of these findings suggests as many as 1,806 sailors may have been affected during the outbreak, of which only 26% (of the 57 outbreak related cases) where identified from sick call records. There was no difference in the mean ages between outbreak and non-outbreak affected crewmen, or geographic clustering based on berthing or work spaces. Outbreak-related cases reported signs and symptoms of watery-stools (79%), nausea (65%), and vomiting (47%). The mean duration of illness was 28 hr, ranging from 2 to 96 hr. Thirty-one percent of outbreak affected cases reported a sick call visit. Loss of work was reported by 39% of the outbreak affected population. This report documents the epidemic potential of Norwalk virus and the associated impact on fleet operational readiness. Additionally, that this outbreak occurred against a background of 3 other consecutive gastroenteritis outbreaks onboard the same ship (March 1997, February/March 1998, and June 1998), all sharing the same clinical and epidemiologic profiles, suggests possible shipboard persistence of Norwalk virus over time, despite periodic ship-wide disinfection efforts.
Epidemiology of the incidence of oro-facial noma: a study of cases in Dakar, Senegal, 1981-1993.
Authors: Bourgeois D M , Diallo B , Frieh C , Leclercq M H
Published: May 2017

Oro-facial noma is an oral gangrene occurring in early childhood in extremely poor areas. As many as 70-90% of those with noma die, and to date, there is no satisfactory treatment to fight this disease. Within the context of the World Health Organization international program against noma, a 13-year retrospective study based on clinical records was carried out in Dakar, Senegal in an attempt to understand the epidemiology of noma. Between 1981 and 1993, 199 cases of noma were identified, among them; 36.7% were acute cases and 63.3% showed sequelae. Chronic sequelae of noma were seen in patients 2-41 years of age, but the acute phase of noma was found only in young children (77.7% in those 1-4 years of age, maximum age = 9 years, mean age +/- SD age = 3.4 +/- 1.9 years). A total of 73.1% of the cases with acute disease were reported in the Dakar, Diourbel and Kaolack regions during the dry season (57.0% of the cases). The lesions of progressive noma were localized mainly on the upper lip (42.4%) and the cheek (31.1%). A total of 96.9% of the patients with acute diseases were had poor general health with serious associated diseases; only 20.0% had a good vital prognosis. The development of epidemiologic surveillance programs for noma should be a public health priority in Senegal.
Epidemiologic aspects of American visceral leishmaniasis in an endemic focus in Eastern Venezuela.
Authors: Zulueta A M , Villarroel E , Rodriguez N , Feliciangeli M D , Mazzarri M , Reyes O , Rodriguez V , Centeno M , Barrios R M , Ulrich M
Published: May 2017

An endemic focus of American visceral leishmaniasis (AVL) in eastern Venezuela has been evaluated in terms of patients (n = 48), immunologic reactivity to Leishmania in household contacts (n = 187) and neighborhood controls (n = 170), detection of Leishmania (L. donovani complex) in dogs and wild animals by the polymerase chain reaction (PCR) and characteristics of the sandfly population. The male:female ratio of patients was 1.18:1; 89.6% were < or =12 years old. Serologic reactivity was significantly higher in household contacts than in controls (P = 0.0008), as was the size of leishmanin reactions in contacts < or =10 years of age (P = 0.0141). Leishmania donovani complex-specific PCRs were positive in dogs, an opossum (Didelphis marsupialis), and a black rat (Rattus rattus). Lutzomyia longipalpis and Lu. evansi, both implicated in the transmission of AVL, were identified among the 386 sand flies examined. These observations provide the bases for an active control program as well as further studies of reservoirs and vector-host relationships in this area.
Geographic distribution and epidemiology of Oesophagostomum bifurcum and hookworm infections in humans in Togo.
Authors: Pit D S , Rijcken F E , Raspoort E C , Baeta S M , Polderman A M
Published: May 2017

In contrast to the rest of the world, infections with Oesophagostomum bifurcum are commonly found in humans in northern Togo and Ghana. In addition, infections with hookworm are endemic in this region. In the present study, a detailed map of the geographic distribution of O. bifurcum and hookworm infections in northern Togo was made. There were a number of foci with high prevalence of infection with O. bifurcum. All the villages examined were infected with hookworm, and the distribution was quite patchy. Women were infected with O. bifurcum more often than men, while infections with hookworm were more prevalent in men than in women. The prevalence and intensity of infection with both parasites were clearly age-dependent. We estimate that more than a 100,000 people in Togo are infected with O. bifurcum and more than 230,000 are infected with hookworm.
Response of cutaneous leishmaniasis (chiclero's ulcer) to treatment with meglumine antimoniate in Southeast Mexico.
Authors: Vargas-Gonzalez A , Canto-Lara S B , Damian-Centeno A G , Andrade-Narvaez F J
Published: May 2017

Cutaneous leishmaniasis, known as chiclero's ulcer in southeastern Mexico, is characterized by a predominantly single, painless, ulcerated lesion, without lymphangitis or adenopathy. When located on the ear, it tends to become chronic, causing destruction of the pinna and disfigurement. It is caused predominantly by Leishmania (L.) mexicana. Although pentavalent antimonials (Sb5+) are the mainstay of leishmanial therapy and have been used for more than 50 years, dosage regimens have been repeatedly modified and the best one has not been fully identified. The main purpose of the present study was to investigate the response of chiclero's ulcer to treatment with meglumine antimoniate. One hundred five patients were treated with meglumine antimoniate at a daily dose of 1 ampule per day (425 mg of Sb5+) until healing. The lesions healed after a mean of 25 days (range = 5-60 days).
Assessment of therapeutic response of Plasmodium falciparum to chloroquine and sulfadoxine-pyrimethamine in an area of low malaria transmission in Colombia.
Authors: Osorio L E , Giraldo L E , Grajales L F , Arriaga A L , Andrade A L , Ruebush T K , Barat L M
Published: May 2017

Although chloroquine (CQ) resistance was first reported in Colombia in 1961 and sulfadoxine-pyrimethamine (SP) resistance in 1981, the frequency of treatment failures to these drugs in Colombia is unclear. A modified World Health Organization 14-day in vivo drug efficacy test for uncomplicated Plasmodium falciparum malaria in areas with intense malaria transmission was adapted to reflect the clinical and epidemiologic features of a low-intensity malaria transmission area in the Pacific Coast Region of Colombia. Patients > or =1 year of age with a parasite density > or =1,000 asexual parasites per microliter were enrolled in this study. Forty-four percent (24 of 54) of the CQ-treated patients were therapeutic failures, including 7 early treatment failures (ETFs) and 17 late treatment failures (LTFs). Four (6%) of 67 SP-treated patients were therapeutic failures (2 ETFs and 2 LTFs). Therapeutic failure in the CQ-treated group was associated with an age <15 years old (P < 0.01), but was not associated with initial parasite density, the presence of CQ or sulfa-containing drugs in urine, or a history of malaria. The high level of therapeutic failures to CQ detected in this study underscores the need and importance of drug efficacy evaluation in the development of a rational national antimalarial drug policy. The relatively low level of therapeutic failures to SP compared with other South American countries raises further questions regarding factors that might have prevented the rapid development of in vivo resistance to this drug combination.
Plasmodium falciparum parasites in French Guiana: limited genetic diversity and high selfing rate.
Authors: Ariey F , Chalvet W , Hommel D , Peneau C , Hulin A , Mercereau-Puijalon O , Duchemin J B , Sarthou J L , Reynes J M , Fandeur T
Published: May 2017

The genetic characteristics of Plasmodium falciparum isolates collected in French Guiana, where malaria transmission is low and occurs in isolated foci, were studied. Blood samples were collected from 142 patients with symptomatic malaria and typed using a polymerase chain reaction-based strategy for merozoite surface protein-(MSP-1) block 2, the MSP-2 central domain, and glutamate-rich protein (GLURP) repeat domain polymorphism. This showed that the parasite population circulating in French Guiana presented a limited number of allelic forms (4, 2, and 3 for MSP-1 block 2, MSP-1, and GLURP, respectively) and a small number of mixed infections, contrasting with the large genetic diversity of parasite populations and infection complexity reported for Africa, Asia, and other parts of South America. Two groups of isolates displaying identical 3 loci allele combinations were further studied for the Pf332 antigen, histidine-rich protein-1, thrombospondin-related anonymous protein, and Pf60 multigene family polymorphism. Within each group, most isolates were identical for all markers tested. This suggests a high rate of self-fertilization of P. falciparum parasites in French Guiana, resulting in homogenization of the population. The implications of these findings for malaria control in areas of low endemicity are discussed.
Detection and genetic relationship of dengue virus sequences in seventeen-year-old paraffin-embedded samples from Cuba.
Authors: Sariol C A , Pelegrino J L , Martinez A , Arteaga E , Kouri G , Guzman M G
Published: May 2017

This study describes the use of the reverse transcriptase-polymerase chain reaction (RT-PCR) to generate dengue 2 amplicons from paraffin-embedded autopsy tissues collected in Cuba 17 years ago. The presumptive diagnoses had been made only by clinical evolution without serologic confirmation. This study confirms once again that dengue 2 virus was directly associated with the fatal cases in children and illustrates the potential of the RT-PCR for retrospective diagnosis of dengue cases 17 years after death. A close similarity in the genomic sequences of the dengue 2 RNA detected in tissue samples from fatal cases and those dengue 2 Cuban strains that had been previously investigated confirms the appropriate genomic classification of the etiologic agent associated with the 1981 dengue hemorrhagic fever Cuban epidemic.
Detection of dengue infection in patients investigated for leptospirosis in Barbados.
Authors: Levett P N , Branch S L , Edwards C N
Published: May 2017

The annual incidence of leptospirosis in Barbados is approximately 13 severe cases/100,000. The peak incidence occurs in October to December of each year, coinciding with the months of heaviest rainfall. During the second half of 1995, an epidemic of dengue type 1 infection produced almost 1,000 laboratory-confirmed cases. During the same period, leptospirosis mortality was twice the average, suggesting that some cases of leptospirosis were being misdiagnosed and treated inappropriately. Sera from patients investigated for dengue or leptospirosis were analyzed retrospectively to determine the extent of misdiagnosis. During 1995 and 1996, 31 of 139 and 29 of 93 patients, respectively, were confirmed as having leptospirosis. Sera from the remaining leptospirosis-negative patients were tested for IgM antibodies to dengue virus. During 1995 and 1996, 48 of 108 patients and 21 of 64 patients, respectively, were found to have dengue. In 1997, sera from all patients investigated for leptospirosis were also tested prospectively for IgM antibodies to dengue: 38 of 92 leptospirosis-negative patients (41%) were dengue IgM-positive, while 2 of 25 leptospirosis cases also had serologic evidence suggesting acute dengue infection. A second large outbreak of dengue caused by serotype 2 occurred in 1997. During the 1995 and 1997 dengue epidemics in Barbados, dengue cases outnumbered leptospirosis cases investigated in the leptospirosis diagnostic protocol. During 1997, patients investigated but negative for dengue were also tested for anti-leptospiral IgM: 7.3% (19 of 262) were IgM-positive. Substantial misdiagnosis of both dengue and leptospirosis can occur and greater public awareness and clinical suspicion of the similar presentations of these two diseases are necessary.
The epidemiology of schistosomiasis in Egypt: Menofia Governorate.
Authors: Abdel-Wahab M F , Esmat G , Medhat E , Narooz S , Ramzy I , El-Boraey Y , Strickland G T
Published: May 2017

Health questionnaires and parasitologic examinations of urine and stool were performed upon a stratified random sample of 10,899 individuals from 1,537 households in 27 rural communities in Menofia Governorate in Egypt in 1992 to investigate the prevalence of, risk factors for, and changing pattern of infection with Schistosoma sp. in the governorate. A subset, every fifth household, or 1,480 subjects, had physical and ultrasound examinations to investigate prevalence of and risk factors for morbidity. The prevalence of S. mansoni ranged from 0.3% to 72.9% and averaged 28.5%. The geometric mean egg count was 81.3 eggs/gram of stool. Age-stratified prevalence and intensity of infection was 30-40% and 60-80 eggs/gram of stool from the age of 10 onward; males had higher infection rates and ova counts than females in all age groups > 10 years old. Schistosoma haematobium was rare, being consequential in only 1 community. Risk factors for S. mansoni infection were male gender; age > 10 years; living in smaller communities; exposures to canal water; history of or treatment for schistosomiasis or blood in the stool; detection of splenomegaly by either physical or ultrasound; and ultrasound-detected periportal fibrosis (PPF). The more severe grades of PPF were rarely (21 of 1,450 examinations) detected. Risk factors for morbidity, i.e., ultrasound-detected PPF, were similar to those for infection. Schistosoma mansoni has almost totally replaced S. haematobium in Menofia. The prevalence of S. mansoni in rural communities remains high and average intensities of infection are moderate. The association of morbidity with schistosomal infection was variable and is obviously markedly influenced by both the frequent use of antischistosomal chemotherapy in communities in Menofia and by the prevalence of complications from chronic viral hepatitis in the population: hepatomegaly did not correlate with infection; PPF and splenomegaly, however, were related to S. mansoni infection in both individuals and communities.
Application of a polymerase chain reaction-ELISA to detect Wuchereria bancrofti in pools of wild-caught Anopheles punctulatus in a filariasis control area in Papua New Guinea.
Authors: Bockarie M J , Fischer P , Williams S A , Zimmerman P A , Griffin L , Alpers M P , Kazura J W
Published: May 2017

Chemotherapy-based eradication programs are aimed at stopping transmission of Wuchereria bancrofti by its obligatory mosquito vector. This study compares one year post-treatment W. bancrofti infection rates of Anopheles punctulatus, the main vector of lymphatic filariasis in Papua New Guinea, using traditional dissection techniques and a polymerase chain reaction (PCR)-based ELISA of a parasite-specific Ssp I repeat. A total of 633 mosquitoes in 35 batches were dissected. Six batches contained W. bancrofti-infected mosquitoes, giving a minimum infection rate of 0.9%. This value was not different than the actual infection rate, which was 9 (1.4%) of 633 mosquitoes (P = 0.48). The DNA was extracted from 47 pools containing a mean of 13.2 mosquitoes per pool. A total of 621 mosquitoes were processed for the PCR-ELISA, including 486 caught by human bait and 135 by light trap, which included both dead and live mosquitoes. Of 23 pools of alcohol-preserved human-bait mosquitoes, seven were positive by the PCR-ELISA, giving an infection rate identical to that obtained by dissection of individual mosquitoes (1.4%). The minimum infection rates for pools of light-trap mosquitoes found dead and alive were 2.7% (2 of 74) and 4.9% (3 of 61), respectively. These values did not differ from each other (P = 0.84), but the overall infection rate of light-trap mosquitoes was greater than that of mosquitoes captured by human bait (3.7% versus 1.4%; P = 0.09). These data indicate that the PCR-ELISA of a W. bancrofti Ssp I repeat using pools of mosquitoes is comparable to traditional dissection techniques for monitoring transmission intensity following introduction of mass chemotherapy. This approach may also be useful for rapid and cost-effective assessment of transmission in endemic areas where the frequency of overt lymphatic pathology is low.
Potential for New York mosquitoes to transmit West Nile virus.
Authors: Turell M J , O'Guinn M , Oliver J
Published: May 2017

We evaluated the potential for several North American mosquito species to transmit the newly introduced West Nile (WN) virus. Mosquitoes collected in the New York City Metropolitan Area during the recent (1999) WN outbreak were allowed to feed on chickens infected with WN virus isolated from a crow that had died during this outbreak. These mosquitoes were tested approximately 2 weeks later to determine infection, dissemination, and transmission rates. Culex pipiens mosquitoes were highly susceptible to infection, and nearly all individuals with a disseminated infection did transmit WN virus by bite. In contrast, Aedes vexans were only moderately susceptible to oral infection; however, those individuals inoculated with WN virus did transmit virus by bite.
Molecular typing of Trichomonas vaginalis isolates by HSP70 restriction fragment length polymorphism.
Authors: Stiles J K , Shah P H , Xue L , Meade J C , Lushbaugh W B , Cleary J D , Finley R W
Published: May 2017

Subtyping isolates of Trichomonas vaginalis is an essential tool for understanding the epidemiology of this common sexually-transmitted disease. Restriction fragment length polymorphism (RFLP) analysis employing a probe from the heat-inducible cytoplasmic HSP70 gene family hybridized with EcoR I-digested genomic DNA was used in the molecular typing of Trichomonas isolates. Analysis of five American Type Culture Collection (ATCC) reference strains and 31 Jackson, Mississippi, isolates from six male and 21 female patients, revealed 10 distinct RFLP pattern subtypes of Trichomonas. The subtypes were temporally stable and cosmopolitan. The RFLP profiles seen in Maryland, Ohio, Massachusetts, and New York ATCC strains were identical to those of some Mississippi isolates, even though the samples were isolated 10-35 years apart. There was no correlation between metronidazole resistance and RFLP subtype with resistant isolates from eight patients distributed among six different subtypes.
A simplified model for predicting malaria entomologic inoculation rates based on entomologic and parasitologic parameters relevant to control.
Authors: Killeen G F , McKenzie F E , Foy B D , Schieffelin C , Billingsley P F , Beier J C
Published: May 2017

Malaria transmission intensity is modeled from the starting perspective of individual vector mosquitoes and is expressed directly as the entomologic inoculation rate (EIR). The potential of individual mosquitoes to transmit malaria during their lifetime is presented graphically as a function of their feeding cycle length and survival, human biting preferences, and the parasite sporogonic incubation period. The EIR is then calculated as the product of 1) the potential of individual vectors to transmit malaria during their lifetime, 2) vector emergence rate relative to human population size, and 3) the infectiousness of the human population to vectors. Thus, impacts on more than one of these parameters will amplify each other's effects. The EIRs transmitted by the dominant vector species at four malaria-endemic sites from Papua New Guinea, Tanzania, and Nigeria were predicted using field measurements of these characteristics together with human biting rate and human reservoir infectiousness. This model predicted EIRs (+/- SD) that are 1.13 +/- 0.37 (range = 0.84-1.59) times those measured in the field. For these four sites, mosquito emergence rate and lifetime transmission potential were more important determinants of the EIR than human reservoir infectiousness. This model and the input parameters from the four sites allow the potential impacts of various control measures on malaria transmission intensity to be tested under a range of endemic conditions. The model has potential applications for the development and implementation of transmission control measures and for public health education.
Simple anamnestic questions and recalled water-contact patterns for self-diagnosis of Schistosoma mansoni infection among schoolchildren in western CÃ´te d'Ivoire.
Authors: Utzinger J , N'Goran E K , Tanner M , Lengeler C
Published: May 2017

A study to determine the diagnostic performance of simple anamnestic questions and recalled water-contact patterns for self-diagnosis of Schistosoma mansoni infection was carried out in western C te d'Ivoire. A total of 322 schoolchildren were screened over four consecutive days with the Kato-Katz technique to assess S. mansoni and concurrent geohelminth infections. Children were individually interviewed by teachers using a standardized questionnaire asking about symptoms, reported diseases, and water-contact patterns. The cumulative infection prevalence of S. mansoni was 76.4%. Univariate statistics revealed a significant association between the level of S. mansoni infection and three recalled water contact patterns: (1) fishing with nets, (2) swimming/bathing and (3) crossing rivers, but no significant association with reported symptoms and/or reported diseases. Multivariate analysis revealed significant adjusted odds ratios (OR) for crossing the river TchÃ©orbour (OR = 3.90, P = 0.007), crossing the river Sonbour (OR = 3.90, P = 0.008) and swimming/bathing in the latter (OR = 3.28, P = 0.017). The diagnostic performance of these water-contact patterns was characterized by high specificities but low sensitivities, hence negative predictive values. In the village studied here, recalled water-contact patterns were more useful variables than anamnestic questions for schoolchildren's self-diagnosis of S. mansoni infection, but no generalization of these findings beyond this population is possible at this time.
Phase II safety and immunogenicity study of live chikungunya virus vaccine TSI-GSD-218.
Authors: Edelman R , Tacket C O , Wasserman S S , Bodison S A , Perry J G , Mangiafico J A
Published: May 2017

We conducted a phase II, randomized, double-blind, placebo-controlled, safety and immunogenicity study of a serially passaged, plaque-purified live chikungunya (CHIK) vaccine in 73 healthy adult volunteers. Fifty-nine volunteers were immunized one time subcutaneously with the CHIK vaccine and 14 were immunized with placebo (tissue culture fluid). Vaccinees were clinically evaluated intensively for one month, and had repeated blood draws for serological assays (50% plaque-reduction neutralization test) for one year. Except for transient arthralgia in five CHIK vaccinees, the number and severity of local and systemic reactions and abnormal laboratory tests after immunization were similar in CHIK vaccinees and placebo recipients. Fifty-seven (98%) of 58 evaluable CHIK vaccinees developed CHIK neutralizing antibody by day 28, and 85% of vaccinees remained seropositive at one year after immunization. No placebo recipients seroconverted. This promising live vaccine was safe, produced well-tolerated side effects, and was highly immunogenic.
Limited potential for transmission of live dengue virus vaccine candidates by Aedes aegypti and Aedes albopictus.
Authors: Sardelis M R , Edelman R , Klein T A , Innis B L , Putnak J R , Jones J W , Turell M J
Published: May 2017

To evaluate the transmission risk of four live dengue (DEN) vaccine candidates developed by the U.S. Army (DEN-1, 45AZ5 PDK 20; DEN-2, S16803 PDK 50; DEN-3, CH53489 PDK 20; and DEN-4, 341750 PDK 20), we tested 3,010 Aedes aegypti and 1,576 Aedes albopictus mosquitoes blood-fed on 21 volunteers who had been administered one of the four vaccine candidates or the licensed yellow fever (YF) vaccine (17D). We used an indirect immunofluorescence assay (IFA) to detect DEN or YF viral antigen in the heads of mosquitoes. Corresponding to the lack of a detectable viremia among volunteers inoculated 8-13 days previously with live DEN-1 or DEN-2 vaccine candidates, only six mosquitoes developed disseminated infections after feeding on these volunteers. These six mosquitoes included 4 of 247 Ae. albopictus fed on volunteers inoculated with the DEN-1 vaccine candidate and 2 of 528 Ae. aegypti fed on volunteers inoculated with the DEN-2 vaccine candidate. Infection was confirmed in each of these IFA-positive mosquitoes by isolating infectious virus from the mosquito's body in Vero-cell culture. None of the 1,252 or the 969 mosquitoes fed on DEN-3 or DEN-4 recipients, respectively, were infected. Overall, dissemination rates in Ae. albopictus and Ae. aegypti were low. Dissemination rates were 0.5%, 0.3%, < 0.1%, and < 0.1% for the DEN-1 through DEN-4 vaccine candidates, respectively. Because of the observed low dissemination rates, it is unlikely that these vaccine viruses would be transmitted under natural conditions.
The incubation period of hantavirus pulmonary syndrome.
Authors: Young J C , Hansen G R , Graves T K , Deasy M P , Humphreys J G , Fritz C L , Gorham K L , Khan A S , Ksiazek T G , Metzger K B , Peters C J
Published: May 2017

In 1993 Sin Nombre virus was recognized as the cause of hantavirus pulmonary syndrome (HPS) and the deer mouse (Peromyscus maniculatus) was identified as the reservoir host. Surveillance by the Centers for Disease Control and Prevention and state health departments includes investigation to determine the likely site(s) and activities that led to infection, an environmental assessment of the home and workplace, and possibly rodent trappings at these sites. As of December 31, 1998, there were 200 confirmed cases from 30 states (43% case-fatality ratio). The national HPS case registry was examined to determine the incubation period of HPS. Review of 11 case-patients with well-defined and isolated exposure to rodents suggests that the incubation period of HPS is 9 to 33 days, with a median of 14-17 days. Case investigations allow a better understanding of the incubation time of HPS and may define high-risk behaviors that can be targeted for intervention.
Large epidemics of hemorrhagic fevers in Mexico 1545-1815.
Authors: Acuna-Soto R , Romero L C , Maguire J H
Published: May 2017

In 1545, twenty-four years after the Spanish conquest of the Aztec empire, an epidemic of a malignant form of a hemorrhagic fever appeared in the highlands of Mexico. The illness was characterized by high fever, headache, and bleeding from the nose, ears, and mouth, accompanied by jaundice, severe abdominal and thoracic pain as well as acute neurological manifestations. The disease was highly lethal and lasted three to four days. It attacked primarily the native population, leaving the Spaniards almost unaffected. The hemorrhagic fevers remained in the area for three centuries and the etiologic agent is still unknown. In this report we describe, and now that more information is available, analyze four epidemics that occurred in Mexico during the colonial period with a focus on the epidemic of 1576 which killed 45% of the entire population of Mexico. It is important to retrieve such diseases and the epidemics they caused from their purely historical context and consider the reality that if they were to reemerge, they are potentially dangerous.
Human immune response to sand fly salivary gland antigens: a useful epidemiological marker?
Authors: Barral A , Honda E , Caldas A , Costa J , Vinhas V , Rowton E D , Valenzuela J G , Charlab R , Barral-Netto M , Ribeiro J M
Published: May 2017

Antibody (IgG) responses to salivary gland homogenate and to a recombinant salivary protein from the sand fly Lutzomyia longipalpis were investigated using sera from children living in an endemic area of visceral leishmaniasis in Brazil. We classified children into four groups according to their responses to Leishmania antigen: (Group I) positive serology and positive delayed type hypersensitivity (DTH), (Group II) positive serology and negative DTH, (Group III) negative serology and positive DTH, and (Group IV) negative serology and negative DTH. A highly significant correlation was found between anti-salivary gland IgG levels and DTH responses. An L. longipalpis salivary recombinant protein used as an antigen in an enzyme-linked immuno sorbent assay (ELISA) gave a significant but different result. A positive correlation was found between anti-Leishmania IgG and anti-recombinant protein IgG titers. The results indicate that sand fly salivary proteins may be of relevance to the study the epidemiology of leishmaniasis.