Parasitic infections: what do paediatricians need to know?

Parasitic infections and the medications used to treat them may be unfamiliar to many paediatricians. Parasitic infections, however, are not uncommonly seen in children in the UK. We summarise infections which are commonly seen, currently recommended treatment and practical guidance on formulations, adverse effects and treatment choice.

Treatment Failure in a UK Malaria Patient Harboring Genetically Variant Plasmodium falciparum From Uganda With Reduced In Vitro Susceptibility to Artemisinin and Lumefantrine.

BACKGROUND: Recent cases of clinical failure in malaria patients in the United Kingdom (UK) treated with artemether-lumefantrine have implications for malaria chemotherapy worldwide. METHODS: Parasites were isolated from an index case of confirmed Plasmodium falciparum treatment failure after standard treatment, and from comparable travel-acquired UK malaria cases. Drug susceptibility in vitro and genotypes at 6 resistance-associated loci were determined for all parasite isolates and compared with clinical outcomes for each parasite donor. RESULTS: A traveler, who returned to the UK from Uganda in 2022 with Plasmodium falciparum malaria, twice failed treatment with full courses of artemether-lumefantrine. Parasites from the patient exhibited significantly reduced susceptibility to artemisinin (ring-stage survival, 17.3% [95% confidence interval {CI}, 13.6%-21.1%]; P < .0001) and lumefantrine (effective concentration preventing 50% of growth = 259.4 nM [95% CI, 130.6-388.2 nM]; P = .001). Parasite genotyping identified an allele of pfk13 encoding both the A675V variant in the Pfk13 propeller domain and a novel L145V nonpropeller variant. In vitro susceptibility testing of 6 other P. falciparum lines of Ugandan origin identified reduced susceptibility to artemisinin and lumefantrine in 1 additional line, also from a 2022 treatment failure case. These parasites did not harbor a pfk13 propeller domain variant but rather the novel nonpropeller variant T349I. Variant alleles of pfubp1, pfap2mu, and pfcoronin were also identified among the 7 parasite lines. CONCLUSIONS: We confirm, in a documented case of artemether-lumefantrine treatment failure imported from Uganda, the presence of pfk13 mutations encoding L145V and A675V. Parasites with reduced susceptibility to both artemisinin and lumefantrine may be emerging in Uganda.

Imported rickettsial infections to the United Kingdom, 2015-2020.

OBJECTIVE: The burden of imported rickettsial infection in the UK is not previously described. This retrospective review identifies rickettsial cases diagnosed at the national reference laboratory between 2015 and 2022. METHODS: Samples testing positive for spotted fever group, typhus group, and scrub typhus IgG/IgM on acute and convalescent blood samples, and/or PCR on tissue/blood were categorized as suspected, confirmed or past infection. RESULTS: 220 patients had rickettsioses, and the commonest import was acute spotted fever group infection (61%, 125/205), 54% (62/114) from South Africa. In acute typhus group cases, 60% (40/67) were from Southeast Asia. One patient with Rickettsia typhi bacteremia died. Scrub typhus group infections (5%, 10/205) were exclusively from Asia and the Western Pacific regions. Overall, 43% of confirmed cases (39/91) had not received doxycycline prior to results. CONCLUSIONS: Rickettsial infections are important and under-recognized causes of imported fever in the UK. Thorough history, examination, and timely treatment with doxycycline should be considered if there is suspicion of Rickettsia infection before testing.

Invasive Group A Streptococcus Outbreaks Associated with Home Healthcare, England, 2018-2019.

Healthcare-associated invasive group A Streptococcus (iGAS) outbreaks are common worldwide, but only England has reported outbreaks associated with home healthcare (HHC). We describe 10 outbreaks during 2018-2019 in England. A total of 96 iGAS cases (range 2-39 per outbreak) and 28 deaths (case-fatality rate 29%) occurred. Outbreak duration ranged from 3-517 days; median time between sequential cases was 20.5 days (range 1-225 days). Outbreak identification was difficult, but emm typing and whole-genome sequencing improved detection. Network analyses indicated multiple potential transmission routes. Screening of 366 HHC workers from 9 outbreaks identified group A Streptococcus carriage in just 1 worker. Outbreak control required multiple interventions, including improved infection control, equipment decontamination, and antimicrobial prophylaxis for staff. Transmission routes and effective interventions are not yet clear, and iGAS outbreaks likely are underrecognized. To improve patient safety and reduce deaths, public health agencies should be aware of HHC-associated iGAS.

Disseminated cerebral hydatid disease (multiple intracranial echinococcosis).

Intracranial echinococcosis is relatively uncommon and usually occurs in the context of echinococcal lesions elsewhere in the body, mostly liver and lung. Multiple intracranial lesions can result from rupture of an initial single intracranial cyst (in cystic echinococcosis) or from dissemination of systemic disease of the lung, liver or heart (cystic and alveolar echinococcosis). The two main subtypes, cystic and alveolar echinococcosis, present differently and have distinct imaging features in the brain. We discuss the presentation, imaging findings and clinical course of three cases (two cystic and one alveolar) of intracranial echinococcal disease in adults.

Geographical and temporal trends and seasonal relapse in Plasmodium ovale spp. and Plasmodium malariae infections imported to the UK between 1987 and 2015.

BACKGROUND: Plasmodium ovale spp. and P. malariae cause illness in endemic regions and returning travellers. Far less is known about these species than P. falciparum and P. vivax. METHODS: The UK national surveillance data, collected 1987 to 2015, were collated with the International Passenger Survey and climatic data to determine geographical, temporal and seasonal trends of imported P. ovale spp. and P. malariae infection. RESULTS: Of 52,242 notified cases of malaria, 6.04% (3157) were caused by P. ovale spp. and 1.61% (841) by P. malariae; mortality was 0.03% (1) and 0.12% (1), respectively. Almost all travellers acquired infection in West or East Africa. Infection rate per travel episode fell fivefold during the study period. The median latency of P. malariae and P. ovale spp. was 18 and 76 days, respectively; delayed presentation occurred with both species. The latency of P. ovale spp. infection imported from West Africa was significantly shorter in those arriving in the UK during the West African peak malarial season compared to those arriving outside it (44 days vs 94 days, p < 0.0001), implying that relapse synchronises with the period of high malarial transmission. This trend was not seen in P. ovale spp. imported from East Africa nor in P. malariae. CONCLUSION: In West Africa, where malaria transmission is highly seasonal, P. ovale spp. may have evolved to relapse during the malarial high transmission season. This has public health implications. Deaths are very rare, supporting current guidelines emphasising outpatient treatment. However, late presentations do occur.

Whole genome analysis of hypervirulent Klebsiella pneumoniae isolates from community and hospital acquired bloodstream infection.

BACKGROUND: Hypervirulent K. pneumoniae (hvKp) causes severe community acquired infections, predominantly in Asia. Though initially isolated from liver abscesses, they are now prevalent among invasive infections such as bacteraemia. There have been no studies reported till date on the prevalence and characterisation of hvKp in India. The objective of this study is to characterise the hypervirulent strains isolated from bacteraemic patients for determination of various virulence genes and resistance genes and also to investigate the difference between healthcare associated and community acquired hvKp with respect to clinical profile, antibiogram, clinical outcome and molecular epidemiology. RESULTS: Seven isolates that were susceptible to all of the first and second line antimicrobials and phenotypically identified by positive string test were included in the study. They were then confirmed genotypically by presence of rmpA and rmpA2 by PCR. Among the study isolates, four were from patients with healthcare associated infections; none were fatal. All patients with community acquired infection possessed chronic liver disease with fatal outcome. Genes encoding for siderophores such as aerobactin, enterobactin, yersiniabactin, allantoin metabolism and iron uptake were identified by whole genome sequencing. Five isolates belonged to K1 capsular type including one K. quasipneumoniae. None belonged to K2 capsular type. Four isolates belonged to the international clone ST23 among which three were health-care associated and possessed increased virulence genes. Two novel sequence types were identified in the study; K. pneumoniae belonging to ST2319 and K. quasipneumoniae belonging to ST2320. Seventh isolate belonged to ST420. CONCLUSION: This is the first report on whole genome analysis of hypervirulent K. pneumoniae from India. The novel sequence types described in this study indicate that these strains are evolving and hvKp is now spread across various clonal types. Studies to monitor the prevalence of hvKp is needed since there is a potential for the community acquired isolates to develop multidrug resistance in hospital environment and may pose a major challenge for clinical management.

Extremely High Mortality Rates in Patients with Carbapenem-resistant, Hypermucoviscous Klebsiella pneumoniae Blood Stream Infections.

BACKGROUND: Infections caused by carbapenem resistant K. pneumoniae are increasing and associated with high mortality rates. There are increasing reports of hypermucoviscous/ hypervirulent K. pneumoniae isolated from various sources. However, there is limited data on the prevalence of hypermucoviscous strains among carbapenem-resistant K. pneumoniae from invasive infections in India and its association with mortality. rmpA, rmpA2 and magA genes are associated with these hypervirulent strains. In this study, we investigate the prevalence of hypermucoviscous strains amongst carbapenem resistant K. pneumoniae isolated from blood culture. Association of mortality rate with meropenem minimum inhibitory concentration and hypermucoviscous strains are determined. METHODS: 86 non-repetitive carbapenem resistant K. pneumoniae isolated from bacteremia underwent E-test for meropenem minimum inhibitory concentration (MIC) determination and PCR for detection of carbapenamase genes. String test, PCR for rmpA, rmpA2 and magA were performed for characterisation of hypervirulent strains. Results: 31.3% of the 86 isolates displayed hypermucoviscous phenotype as indicated by a positive string test. Among the two genotypic markers, 7% were positive for rmpA2 and all were negative for rmpA and magA. 74.1% and 67.9% mortality were seen among string test positives and isolates meropenem MIC of ≥16µg/ml respectively (p 0.036 and 0.008 respectively). Isolates with both string positivity and meropenem MIC of ≥16µg/ml had a very high mortality rate of 84.2%. CONCLUSION: String test, aids prediction of disease severity, and is independently associated with increased mortality in invasive carbapenem resistant K.pneumoniae health care-acquired infections. High meropenem MIC is a significant risk factor for mortality. Combination of string positive carbapenem resistant hypermucoviscous K. pneumoniae resulted in mortality rate of 84.2%. It is important to monitor prevalence of carbapenem resistant hypermucoviscous/hypervirulent K. pneumoniae among invasive isolates especially in a setting with high resistance rates as combination of increased virulence and decreased susceptibility to antimicrobials results in worse outcomes.

Diagnosis and management of Panton-Valentine leukocidin toxin associated Staphylococcus aureus infection: an update.

The incidence of invasive Staphylococcus aureus (SA) infection has increased in the past decade and is associated with poor outcomes and high mortality rates. Of all the virulence factors, Panton-Valentine Leukocidin (PVL) has received the greatest attention. PVL producing SA strains are more likely to produce severe skin and soft tissue infections (SSTIs) and necrotizing pneumonia. This review focuses on the current evidence on PVL-SA virulence, epidemiology, clinical disease and treatment with relevance to healthcare in India.

Toscana virus meningo-encephalitis: an important differential diagnosis for elderly travellers returning from Mediterranean countries.

BACKGROUND: Elderly patients have a long list of differentials for causes of acute confusion and altered consciousness levels, including infectious agents. In addition, elderly, retired patients often have more time to travel for tourism, particularly to exotic, warmer locations. Mediterranean countries such as Spain and Italy are popular holiday destinations for British and other tourists, especially during the winter months. However, these warm climates allow insect vectors to proliferate, increasing the risk of exposure to endemic vectorborne viral infections whilst on vacation. Such infections may not be routinely considered by geriatric medical teams. CASE PRESENTATION: An 87-year old gentleman presented with a three-day history of worsening confusion, lethargy, ataxia, and fevers following a trip to Spain, where he may have sustained a sandfly bite. By the time of admission, he had a reduced GCS, was hallucinating, and was incontinent of urine and faeces, though blood pressure and heart rate were normal. He also appeared hyperaesthetic, and found even capillary blood sugar testing extremely painful. He had no history of cognitive defect or other neurological conditions. He had been previously independently active, with frequent trips to Spain where he maintained a holiday home. He probably sustained a sandfly bite during this most recent trip, whilst cleaning out a shed. Acute and convalescent sera demonstrated IgG antibodies to Toscana virus at extremely high titres of ≥1:10,000 by immunofluorescence assay, though no Toscana virus RNA was detectable in these sera by the time of presentation. CONCLUSIONS: Toscana virus should be included in the differential diagnosis of any patients presenting with meningo-encephalitis who have recently returned from a Mediterranean country. Testing for Toscana virus infection is performed by serological testing on acute/convalescent paired sera, and/or a polymerase chain reaction (PCR) assay on blood or cerebrospinal fluid (CSF) if presenting within 5 days of illness onset. Making a diagnosis of Toscana virus meningitis/encephalitis (where no other pathogen is detected) has additional clinical utility in reducing or preventing unnecessary use of antibiotics, as well as reassuring the patient and family that generally, this illness is generally self-limiting and full recovery within a few weeks is expected, as in the case reported here.

Evolving Rapid Methicillin-resistant Staphylococcus aureus Detection: Cover All the Bases.

The dissemination of methicillin-resistant (MR) Staphylococcus aureus (SA) in community and health-care settings is of great concern and associated with high mortality and morbidity. Rapid detection of MRSA with short turnaround time can minimize the time to initiate appropriate therapy and further promote infection control. Early detection of MRSA directly from clinical samples is complicated by the frequent association of MRSA with methicillin-susceptible SA (MSSA) and coagulase-negative Staphylococcus (CoNS) species. Infection associated with true MRSA or MSSA is differentiated from CoNS, requires target specific primers for the presence of SA and mec A or nuc or fem A gene for confirmation of MR. Recently, livestock-associated MRSA carrying mec C variant complicates the epidemiology of MRSA further. Several commercial rapid molecular kits are available with a different combination of these targets for the detection of MRSA or MSSA. The claimed sensitivity and specificity of the currently available commercial kits is varying, because of the different target combination used for detection of SA and MR.

Clinical and Bacterial Risk Factors for Mortality in Children With Carbapenem-resistant Enterobacteriaceae Bloodstream Infections in India.

BACKGROUND: Carbapenem-resistant Enterobacteriaceae (CRE) are an increasing cause of nosocomial infection in hospitalized children worldwide. Few studies have investigated risk factors for mortality in children with CRE bloodstream infection (BSI). Data are particularly scarce in areas where NDM and OXA carbapenemases predominate. Here, we investigate mortality rates, clinical and microbiologic risk factors for mortality in 50 pediatric patients with CRE BSI in India. METHODS: Children younger than 17 years old with meropenem-resistant Klebsiella pneumoniae or Escherichia coli isolated from blood culture in 2014 and 2015 were identified from laboratory records. Clinical records were systematically reviewed for each child to establish mortality at 30 days and clinical details. Bacterial isolates were subjected to meropenem E test and multiplex polymerase chain reaction to determine carbapenemase gene. Data were analyzed to establish clinical and bacterial risk factors for mortality. RESULTS: All CRE BSI were hospital-acquired or associated with healthcare. A total of 84% of children had an underlying comorbidity and 46% had a malignancy. K. pneumoniae was the most common bacteria isolated; NDM was the most common carbapenemase gene detected. The mortality rate was 52%. Significant risk factors for mortality included intensive care admission, intubation, inotropic support and respiratory source. Failure to clear bacteremia and a minimum inhibitory concentration > 8 mg/L for the isolate was associated with a statistically significant increase in mortality. Mortality rates were significantly lower when two or more effective drugs were used in combination. CONCLUSIONS: CRE BSI affects children with multiple comorbidities and repeated admissions to hospital. The mortality rate is high; combination therapy may be beneficial.

Minocycline and Tigecycline: What Is Their Role in the Treatment of Carbapenem-Resistant Gram-Negative Organisms?

Carbapenem-resistant organisms are increasingly common worldwide, particularly in India and are associated with high mortality rates especially in patients with severe infection such as bacteremia. Existing drugs such as carbapenems and polymyxins have a number of disadvantages, but remain the mainstay of treatment. The tetracycline class of antibiotics was first produced in the 1940s. Minocycline, tetracycline derivative, although licensed for treatment of wide range of infections, has not been considered for treatment of multidrug-resistant organisms until recently and needs further in vivo studies. Tigecycline, a derivative of minocycline, although with certain disadvantages, has been frequently used in the treatment of carbapenem-resistant organisms. In this article, we review the properties of minocycline and tigecycline, the common mechanisms of resistance, and assess their role in the management of carbapenem-resistant organisms.

Draft Genome Sequences of Three Hypervirulent Carbapenem-Resistant Klebsiella pneumoniae Isolates from Bacteremia.

Hypervirulent Klebsiella pneumoniae strains have been increasingly reported worldwide, and there is emergence of carbapenem resistance among them. Here, we report the genome sequences of three carbapenem-resistant hypervirulent K. pneumoniae isolates isolated from bacteremic patients at a tertiary-care center in South India.

Administración de esteroides y talidomida para el control del eritema nodoso leproso durante 17 años en el hospital para enfermedades tropicales de Londres / No disponible

Objetivos: La prednisolona y la talidomida se administran frecuentemente en el control del eritema nodoso leproso (ENL) y proporcionan alivio a los pacientes con esta condición en todo el mundo. Sin embargo, tanto el ENL como sus tratamientos causan gran morbilidad. Este trabajo describe el espectro del ENL observado en el Hospital para Enfermedades Tropicales de Londres (HTD), la utilización de esteroides y el uso de esteroides y talidomida en su control y las consiguientes complicaciones. Metodología: Se llevó a cabo una revisión retrospectiva de los pacientes diagnosticados con ENL entre 1996 y 2013. Los datos se obtuvieron de los archivos clínicos, incluyendo la severidad y duración del episodio, además del tratamiento y efectos adversos. Resultados: Entre 1996 y 2013 se diagnosticaron 30 pacientes con ENL. El índice bacteriológico (IB) promedio en el momento del diagnóstico fue > 4.65, superior al aceptado en otros estudios. La mayoría de los pacientes desarrollaron ENL durante el tratamiento (67%) y presentaron ENL crónico (57%). La duración media del ENL fue de 60 meses (rango 9-192); los pacientes con IB > 4.5 presentaron períodos de tiempo más largos. El 87% de los pacientes recibieron prednisolona durante 9 meses; 33% desarrolló efectos adversos, incluyendo diabetes e hipertensión; el 87% de los pacientes recibió talidomida durante 16 meses y el 65% presentó efectos adversos. No hubo casos de embarazo o tromboembolismo. El 77% de los pacientes dejó la prednisolona a los dos meses de iniciar la talidomida. No hubo casos de fallecimiento en nuestro grupo. Conclusión: Describimos el curso clínico del ENL en un país no endémico con acceso a la talidomida y prednisolona. El ENL puede durar mucho más que el tiempo descrito anteriormente y tiene un gran impacto sobre la salud del paciente. En el Reino Unido, la talidomida es esencial para cesar la administración de los esteroides, prevenir efectos adversos y la mortalidad por esteroides, lo cual esté documentado en otros trabajos

Objectives: Prednisolone and thalidomide are commonly used in the management of erythema nodosum leprosum (ENL) and bring relief to patients with this condition worldwide. However, both ENL and its treatments can cause significant morbidity. This study describes the spectrum of ENL seen at The Hospital for Tropical Diseases, London (HTD), the use of steroids and thalidomide in its management and the complications of their use. Study Design: We conducted a retrospective audit of patients diagnosed with ENL between 1996 and 2013. Data were obtained from hospital records including severity and length of disease, together with treatments received and adverse effects. Results: Between 1996 and 2013, 30 patients were diagnosed with ENL. The median bacillary index (BI) at diagnosis was 4.65, higher than in previous studies. Most patients developed ENL during leprosy treatment (67%) and had chronic ENL (57%). The median length of ENL was 60 months (range 9-192); patients with BI. 4.5 had significantly longer duration of disease. 87% patients received prednisolone for median nine months; 35% developed adverse effects including diabetes and hypertension. 87% patients received thalidomide for median 16 months; 65% complained of side effects. There were no pregnancies or venous thromboembolisms. 77% patients stopped prednisolone within two months of starting thalidomide. There were no deaths in our cohort. Conclusion: We describe the clinical course of ENL in a non-endemic country with access to thalidomide and prednisolone. ENL may last far longer than previously described and has significant impact on a patient’s health. In the UK, thalidomide is essential as a steroid-sparing agent, to prevent the adverse effects and mortality of longterm steroids which have been documented elsewhere

Molecular Mechanisms of Colistin Resistance in Klebsiella pneumoniae Causing Bacteremia from India-A First Report.

Colistin has long been a reserve drug used for the treatment of carbapenem resistant Klebsiella pneumoniae. Carbapenem resistance in K. pneumoniae has been increasing and is as high as 44% in India. Although a reserve agent, with rise in rates of resistance to carbapenems, the usage of colistin has increased over the years leading to slow emergence of resistance. Colistin resistance is mainly mediated by the alteration in the LPS of bacterial outer membrane with the addition of L-Ara4-N and PEtN molecules. These alterations are mediated by mutations in several genes involved in lipidA modifications and most commonly mutations in mgrB gene has been reported. Recently there is emergence of plasmid mediated resistance due to mcr-1 and mcr-2 genes which poses a threat for the rapid global spread. This study aims at characterizing eight colistin resistant K. pneumoniae from bacteremia by whole genome sequencing. Eight K. pneumoniae were isolated from blood culture during 2013 and 2014 at the Department of Clinical Microbiology, Christian Medical College, India. Antimicrobial susceptibility testing was performed and minimum inhibitory concentration (MIC) was determined for colistin and polymyxin B by broth-micro dilution method. Whole genome sequencing was performed using Ion Torrent and the genome of all eight isolates was analyzed. The eight isolates were resistant to all the antimicrobials expect tigecycline. MIC of colistin and polymyxin B were ranged from 4 to 1024 µg/ml and 0.5 to 2048 µg/ml respectively. Multiple mutations were observed in the chromosomal genes involved in lipid A modifications. mcr-1 and mcr-2 gene was absent in all the isolates. The most significant were mutations in mgrB gene. Among the eight isolates, four, three and one were belonged to sequence types ST 231, ST14 and ST147 respectively. Seven isolates had blaOXA-48 like, one co-expressed blaNDM-1 and blaOXA-48 like genes leading to carbapenem resistance. Overall, multiple numbers of alterations have been observed. This includes silent mutations, point mutations, insertions and/or deletions. Mutations in mgrB gene is responsible for resistance to colistin in this study. Due to emergence of resistance to reserve drugs, there is a need for combination therapies for carbapenem resistant K. pneumoniae and colistin must be judiciously used.

Current management of cystic echinococcosis: a survey of specialist practice.

BACKGROUND: Cystic echinococcosis (CE) is a significant public health problem worldwide. However, there remains a dearth of evidence guiding treatment in various stages of CE. The 2010 World Health Organization (WHO) Informal Working Group on Echinococcosis (WHO IWGE) guidance is thus based on expert consensus rather than a good evidence base. This study aims to describe the way clinicians worldwide manage CE and to establish whether clinicians follow WHO IWGE guidance. METHODS: Using the online surveying tool SurveyMonkey, a questionnaire was produced detailing 5 clinical cases. Clinicians treating CE were identified and asked how to manage each case through tick-box and short-answer questions. RESULTS: The results showed great variation in practice worldwide. There are practices in common use that are known to be ineffectual, including puncture, aspiration, injection, reaspiration procedures on WHO type 2 cysts, or outdated, including interrupted, rather than continuous, courses of albendazole. A number of unsafe practices were identified such as using scolicidal agents in cysts communicating with the biliary tree and short-course medical therapy for disseminated disease. Most clinicians do not follow the WHO IWGE guidance, but the reasons for this are unclear. CONCLUSIONS: Management of CE varies greatly worldwide. There are key areas of CE for which there is no evidence on which to base guidelines, and randomized controlled trials are needed together with a well-designed international registry to collect data. Further work is required to establish why clinicians do not follow the IWGE guidance, together with better dissemination of future guidance.