Soc Trop Med Hyg Research Articles

Mediastinal cysts associated with Paragonimus westermani

•Paragonimiasis can rarely manifest as a mediastinal cystic mass.•Paragonimiasis can be transmitted to the mediastinum in the absence of pulmonary lesions.•Surgical resection can aid in the diagnosis and treatment of mediastinal paragonimiasis. A 48-year-old man presented to the thoracic surgery clinic with an incidentally detected mediastinal mass on chest radiography (Figure 1a). He was asymptomatic with no relevant medical history. Laboratory studies showed normal leukocyte and eosinophil counts. Magnetic resonance imaging revealed multilocular cystic lesions (6 × 4.5 cm) with abscess formation in the pericardial space (Figure 1b-d). The first impression was multilocular thymic cysts. The cysts were removed by uniportal video-assisted thoracic surgery (Figure 2). Histologic analysis revealed a multicystic lesion with central necrosis and peripheral granulomas with parasitic eggs in the thymus (Figure 3). He was diagnosed with Paragonimus westermani infection. P. westermani can be transmitted by eating infected raw freshwater crabs [[1]Harinasuta T Pungpak S Keystone JS. Trematode infections. Opisthorchiasis, clonorchiasis, fascioliasis, and paragonimiasis.Infect Dis Clin North Am. 1993; 7: 699-716https://doi.org/10.1016/S0891-5520(20)30550-XAbstract Full Text PDF PubMed Google Scholar], and it mainly presents as subpleural consolidations, pneumothorax, and pleural effusion [[2]Singh TS Mutum SS Razaque MA. Pulmonary paragonimiasis: clinical features, diagnosis and treatment of 39 cases in Manipur.Trans R Soc Trop Med Hyg. 1986; 80: 967-971https://doi.org/10.1016/0035-9203(86)90275-0Abstract Full Text PDF PubMed Scopus (74) Google Scholar]. It is extremely rare that paragonimiasis presents as multilocular cysts in the mediastinum without pulmonary manifestation. He enjoyed eating raw crab marinated in soy sauce, and it is speculated that the larvae migrated through the diaphragm and made an abscess pocket in the anterior mediastinum. At the 15-month follow-up visit after surgical removal and medication of praziquantel, he showed no evidence of recurrence. When presented with unexplained mediastinal multilocular cysts, paragonimiasis can be included in the differential diagnosis.Figure 2Intraoperative observation of a cystic lesion of the anterior mediastinum.View Large Image Figure ViewerDownload Hi-res image Download (PPT)Figure 3Histologic findings of (a) central necrosis and peripheral granulomas (b) with parasitic eggs in the thymus.View Large Image Figure ViewerDownload Hi-res image Download (PPT) The authors have no competing interests to declare.

Estimating antimicrobial resistance burden in Europe—what are the next steps?

Estimating antimicrobial resistance burden in Europe—what are the next steps?

The role of chemoprophylaxis in eliminating forest malaria and preventing simian malaria in humans

The role of chemoprophylaxis in eliminating forest malaria and preventing simian malaria in humans

Chikungunya virus: An emerging public health challenge for Pakistan

Chikungunya virus: An emerging public health challenge for Pakistan

Assessing PfGARP-Mediated Apoptosis of Blood-Stage Plasmodium falciparum Parasites.

Apoptosis is conventionally regarded as an evolutionarily conserved and genetically controlled process of programmed cell death confined to metazoan organisms. However, recently, conserved features of apoptosis have also been demonstrated in unicellular eukaryotes (Holzmuller et al. Parasitology 132:S19-S32, 2006; Le Chat et al. Mol Biochem Parasitol 153:41-47, 2007; Madeo et al. Curr Opin Microbiol 7:655-660, 2004; Welburn et al. Parasitology 132:S7-S18, 2006; Jensen et al. Science 216:1230-1233, 1982) including malaria parasites (Al-Olayan et al. Int J Parasitol 32:1133-1143, 2002; Ch'ng et al. Cell Death Dis 1:e26, 2010; Meslin et al. J Infect Dis 195:1852-1859, 2007; Picot et al. Trans R Soc Trop Med Hyg 91:590-591, 1997; Raj et al. Nature 582:104-108, 2020). P. falciparum glutamic-acid-rich protein (PfGARP) is an antigen of 80kDa that is uniquely expressed on the exofacial surface of red blood cells (RBCs) infected by early-to-late-trophozoite-stage P. falciparum parasites (Raj et al. Nature 582:104-108, 2020). We have recently demonstrated that antibodies against PfGARP bind to the PfGARP displayed on the surface of P. falciparum trophozoite-infected RBCs and trigger apoptosis in the intracellular parasites (Raj et al. Nature 582:104-108, 2020). This is the first demonstration of antibody-induced apoptosis in blood-stage malaria parasites and is characterized by several conserved features such as crisis form morphology, loss of mitochondrial membrane potential, loss of integrity of food vacuole, activation of caspase-like cysteine proteases, and fragmentation of chromosomal DNA. Here we describe the assays used to detect these features of apoptosis in the mature blood stage of malaria parasites.

Historical Features Regarding the Neuropathic Outbreaks in Brazilian Troops in the Paraguayan War.

During the Paraguayan War, Brazilian army and navy officers attributed outbreaks of combatant limb weakness with particular features such as tingling to palustrian causes. A dietary basis was not fully suspected at the time, and the popular name beriberi had not been coined. During wartime, there was a shortage in the food supply in addition to poor environmental conditions and diarrheal diseases, and many reports of "palustrian cachexia" were made. There are also reports of the use of native flora to feed troops, as well as alcoholism. There are also accounts of the death of horses with symptoms similar to those of combatants. It was reported that black soldiers were more resistant to "palustrian cachexia." This article presents the disease ecology and clinical manifestations of beriberi at wartime, linked to starvation and consumption of pickled food and native flora. These military explorations and operations in the Paraguayan War happened more than 150 y ago and present some aspects of wilderness medicine in the past.

Female Voice-Related Sexual Attractiveness to Males: Does it Vary With Different Degrees of Conception Likelihood?

Previous investigations have found that female voice-related attractiveness to males increases when both conception likelihood (CL) and voice fundamental frequency (fo) are elevated. To test this hypothesis, we conducted a perceptual experiment where 78 heterosexual males rated sexual attractiveness of 9 female voice samples, recorded at menstrual, follicular and luteal phases of the menstrual cycle under two double-blinded randomly allocated conditions: a natural menstrual cycle (placebo condition) and when using an oral contraceptive pill (OCP condition). The voice samples yielded a total of 54 stimuli that were visually sorted and rated using Visor software. Concentrations of estrogens, progesterone and testosterone were analyzed, and measurements of speaking fundamental frequency (sfo) and its standard deviation (sfoSD), fo derivative (dfo) and fo slope were made. A multilevel ordinal logistic regression model nested in listeners and in females, and adjusted by phase and condition, was carried out to assess the association between ratings and: (1) phases and conditions; (2) sex steroid hormonal concentrations; and (3) voice parameters. A high probability of obtaining high ratings of voice sexual attractiveness was found for: (1) menstrual phase of placebo use and follicular phase of OCP use; (2) for low estradiol to progesterone ratio and testosterone concentrations; and (3) for low dfo. The latter showed a moderate statistical association with ratings of high attractiveness, as compared with the small association found for the remaining variables. It seems that the voice is a weak cue for female CL. Female sexual attraction to males may be a consequence of what females do in order to regulate their extended sexuality across the menstrual cycle rather than of estrus cues, the use of paralinguistic speech patterns being an example.

From Hendra to Wuhan: what has been learned in responding to emerging zoonotic viruses

From Hendra to Wuhan: what has been learned in responding to emerging zoonotic viruses

Meningococcal strain evolution, dusty dry air and respiratory tract infections: An explosive relationship.

Meningococcal strain evolution, dusty dry air and respiratory tract infections: An explosive relationship.

STRINGS OF FURY: A CASE OF STRONGYLOIDES HYPERINFECTION SYNDROME IN A CHEMOTHERAPY-NAIVE PATIENT WITH EXTENSIVE SCLC

SESSION TITLE: Chest Infections 2 SESSION TYPE: Med Student/Res Case Report PRESENTED ON: 10/09/2018 05:00 PM - 06:00 PM INTRODUCTION: Strongyloidiasis is one of the most neglected tropical diseases. Diagnosis is difficult because of non-specific clinical features, irregular larval output and lack of specific test. This infection can be chronic and asymptomatic but a change in immune status can lead to increased parasite burden, hyperinfection syndrome, dissemination, and death if unrecognized. CASE PRESENTATION: An 80-year old Filipino male diagnosed with Small Cell Lung Cancer - extensive disease (brain and liver metastases) was admitted due to a 5-day history of watery blood-streaked stools, dry cough and decreased sensorium. Dexamethasone was started for raised intracranial pressure. The patient was started on empiric antibiotics for pneumonia (Fig2) and acute gastroenteritis. Fecalysis showed Strongyloides larvae (Fig1) and Albendazole was started. Neurologic and respiratory status worsened and necessitated ventilatory support. Endotracheal aspirate smear revealed Strongyloides rhabditiform larvae (FIg3). Blood culture revealed Klebsiella pneumoniae. Despite adequate antibiotic coverage and discontinuation of steroids, the patient continued to deteriorate and was brought home. DISCUSSION: Hyperinfection is a syndrome of accelerated autoinfection which may or may not result from alteration in immune status. Development of gastrointestinal and pulmonary symptoms is seen. The hallmark is detection of increased numbers of larvae in stool and/or sputum. Regardless of dose or route of administration, even short courses (6-17 days) of steroids in immunocompetent patients have been associated with hyperinfection syndrome and death.Hyperinfections are often complicated and, rarely, preceded by infections caused by gut flora that gain access to extraintestinal sites, presumably through ulcers induced by the filariform larvae or by virtue of being carried on the surface or in the intestinal tract of the larvae themselves. Blood cultures from patients with hyperinfection have grown Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, Pseudomonas, Enterococcus faecalis, coagulase-negative staphylococci, Streptococcus bovis, and Streptococcus pneumoniae.Centers for Disease Control and Prevention recommend that immunosuppressive therapy should be stopped or reduced if possible. Only Ivermectin is recommended for hyperinfection however it is not available in the Philippines. Albendazole is recommended as alternative regimen for acute and chronic forms strongyloidiasis. CONCLUSIONS: As the number of immunosuppressed individuals increase, a more thorough investigation is warranted to detect situations under which S. stercoralis infection can potentially worsen. Early diagnosis is a challenge as it may mimic other diseases. Primary prevention as well as better approaches to identifying, screening, and treating those at risk will likely decrease the morbidity and mortality associated with this hyperinfection syndrome. Reference #1: Olsen A, van Lieshout L, Marti H, et al. Strongyloidiasis - the most neglected of the neglected tropical diseases? Trans R Soc Trop Med Hyg. 2009; 103:967-972. Reference #2: Mejia R, Nutman TB, Screening, prevention, and treatment for hyperinfection syndrome and disseminated infections caused by Strongyloides stercoralis. Opin Infect Dis. 2012 August ; 25(4): 458-463. Reference #3: Keiser PB, Nutman TB. Strongyloides Stercoralis In The Immunocompromised Population. Clinical Microbiology Reviews, Jan. 2004, P. 208-217 DISCLOSURES: no disclosure on file for Raquel Victoria Ecarma; No relevant relationships by Myrna Mendoza, source=Web Response No relevant relationships by Irene Rosellen Tan, source=Web Response

Schistosomiasis in the Senegal River basin

Schistosomiasis in the Senegal River basin

Treatment of preschool children for schistosomiasis.

Treatment of preschool children for schistosomiasis.

Murine Mycobacterium marinum Infection as a Model for Tuberculosis.

Mycobacteria are a major human health problem globally. Regarding tuberculosis the situation is worsened by the poor efficacy of current vaccine regimens and by emergence of drug-resistant strains (Manjelievskaia J et al, Trans R Soc Trop Med Hyg 110: 110, 2016; Pereira et al., Lancet Infect Dis 12:300-306, 2012; http://www.who.int/tb/publications/global_report/en/) undermining both disease-prevention and available treatments. Thus, increased basic understanding of mycobacterial-and particularly Mycobacterium tuberculosis-virulence strategies and pathogenesis is of great importance. To this end several in vivo infection models are available (Guirado and Schlesinger, Front Immunol 4:98, 2013; Leung et al., Eur J Immunol 43:2246-2254, 2013; Patel et al., J Lab Physicians 3:75-79, 2011; van Leeuwen et al., Cold Spring Harb Perspect Med 5:a018580, 2015). While these models all have their merits they also exhibit limitations, and none perfectly mimics all aspects of human tuberculosis. Thus, there is a need for multiple models that may complement each other, ultimately allowing us to gain true insight into the pathogenesis of mycobacterial infections.Here, we describe a recently developed mouse model of Mycobacterium marinum infection that allows kinetic and quantitative studies of disease progression in live animals [8]. Notably, this model exhibits features of human tuberculosis not replicated in M. tuberculosis infected mice, and may provide an important complement to the field. For example, granulomas in the M. marinum model develop central caseating necrosis (Carlsson et al., PLoS Pathog 6:e1000895, 2010), a hallmark of granulomas in human tuberculosis normally not replicated in murine M. tuberculosis infection. Moreover, while tuberculosis is heterogeneous and presents with a continuum of active and latent disease, M. tuberculosis infected mice essentially lack this dynamic range and do not replicate latency (Guirado and Schlesinger, Front Immunol 4:98, 2013; Patel et al., J Lab Physicians 3(2):75-79, 2011). In contrast, M. marinum infected mice may naturally develop latency, as suggested by reduced inflammation and healing of the diseased tissue while low numbers of bacteria persist in granulomatous lesions (Carlsson et al., PLoS Pathog 6:e1000895, 2010). Thus, infection with M. marinum may offer a unique murine model for studying granuloma formation as well as latency-and possibly also for studies of disease-reactivation. In addition to the in vivo model, we describe infection of bone marrow-derived murine macrophages, an in vitro platform enabling detailed mechanistic studies of host-pathogen interactions occurring in the principal host target cell for pathogenic mycobacteria.

Typhoid versus typhus fever in post-earthquake Nepal.

Typhoid versus typhus fever in post-earthquake Nepal.

Research and development for neglected diseases: more is still needed, and faster.

Research and development for neglected diseases: more is still needed, and faster.

Transactions of the Royal Society of Tropical Medicine and Hygiene

This paired case-control study examined the safety and efficacy of using hydrocortisone in children with severe scorpion envenomation requiring the intensive care unit (ICU). The study took place in Tunisia, which has an estimated 40,000 scorpion stings per year, with the most severe envenomations caused by the species Androctonus australis and Butus occitanus. The clinical symptoms and signs of scorpion envenomations are caused by massive catecholamine release, direct venom effects, and generalized inflammation. The authors postulate that steroids may reduce the proinflammatory effect of massive cytokine release after scorpion envenomation; however, this is the first study to directly investigate steroid use for scorpion envenomation in children. The investigators reviewed ICU records for a 13-year period and matched patients receiving steroids with control patients who did not receive steroids by age, severity factors, and scorpion antivenom administration. Primary outcome measures were ICU mortality rate, use of mechanical ventilation, duration of ICU stay, and laboratory analysis. A total of 685 children were admitted for scorpion stings, and 92 received steroids with hydrocortisone hemisuccinate (200–300 mg per 24 hours for 48 hours). The 2 groups had the following similar characteristics: 50% received the scorpion antivenom, 79% developed pulmonary edema or cardiogenic shock, and 66% required catecholamines for hemodynamic support. There was no significant difference in mortality rate (8%), the use of mechanical ventilation (35%), or duration of ICU stay (average 2.6 days) between the 2 groups. The steroid group had a higher rate of hyperglycemia and hypokalemia; however, there were no other significant laboratory differences. The investigators concluded that the prognosis of children with severe scorpion envenomation admitted to the ICU was not improved by the use of hydrocortisone. Limitations of the study include that is was a single-site investigation and potential changes in clinical management during the study period. (Trans R Soc Trop Med Hyg. 2013;107:349–355) M Bahloul, A Chaari, R Ammar, et al.

Gastrointestinal basidiobolomycosis: mimicking Crohn’s disease case report and review of the literature

Gastrointestinal basidiobolomycosis (GIB) is an unusual fungal infection that manifests in the skin and rarely involves other systems. All of the few cases of GIB reported so far were diagnosed with difficulty, necessitating laparotomy and resection of the inflamed part of the bowel. We report a child with GIB who was successfully diagnosed endoscopically without surgical intervention.

PWE-172 Micronutrient-Antioxidant Supplementation has no Impact on Gastric Atrophy in Zambian Adults: A Randomised Controlled Trial

IntroductionWith the increasing number of gastric cancer cases in young patients in Zambia, we set out to investigate the possibility of reversing gastric atrophy, a precancerous lesion, using micronutrient-antioxidant supplementation...

Quick diagnosis of female genital tuberculosis using multiplex fast polymerase chain reaction in Southern Assam, India

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The Variable Presentations and Broadening Geographic Distribution of Hepatic Fascioliasis

We report 2 unrelated cases of hepatic fascioliasis in travelers returning to the United States from Africa and the Middle East. The first case presented with acute infection. Prominent clinical features included abdominal pain, elevated liver transaminases, serpiginous hepatic lesions, pericapsular hematoma, and marked peripheral eosinophilia. The second case was diagnosed in the chronic stage of infection and presented with right upper quadrant abdominal pain, cystic hepatic lesions, and an adult fluke in the common bile duct. We review the life cycle of Fasciola species, the corresponding clinical features during the stages of human infection, diagnostic methods, and the evolving understanding of the epidemiology of human fascioliasis, particularly emphasizing fascioliasis in African countries.