- Email: [email protected]
Reply to comment on: Diagnosing central nervous system trypanosomiasis: two stage or not to stage
Transactions of the Royal Society of Tropical Medicine and Hygiene (2009) 103, 105—107
available at www.sciencedirect.com
journal homepage: www.elsevierhealth.com/journals/trst
CORRESPONDENCE Comment on: Diagnosing central nervous system trypanosomiasis: two stage or not to stage In his scholarly review, Kennedy highlights both the therapeutic importance and the difficulty of differentiating the early or haemolymphatic stage of sleeping sickness from the late or encephalitic stage on clinical grounds.1 Similar difficulties were encountered in the case of cerebral malaria, especially in children in endemic areas, where parasitaemia is so common that it is not in itself diagnostic. And then Lewallen et al. described an unusual retinopathy seen on direct and indirect ophthalmoscopy in 57% of the patients.2 It has now been confirmed that retinal whitening, especially of the macula, and white or orange discoloration of retinal vessels are specific to malaria.3 Has fundoscopy through dilated pupils by trained practitioners been the subject of a clinical trial in patients with sleeping sickness? Might it help in the diagnosis of the encephalitic stage of the illness? Ophthalmologists and neurologists apart, most practitioners are not confident in the use of ophthalmoscopes, and fundoscopy is a muchneglected clinical method. As Denniston (2001) remarks, ‘‘Ophthalmoscopy is many a physician’s ‘blind spot’ . . .’’4
Roger Hanif Armour Lister Hospital, Stevenage, Hitchin, Hertfordshire, UK E-mail address: [email protected] 22 June 2008 Available online 9 August 2008 doi:10.1016/j.trstmh.2008.07.003
Reply to comment on: Diagnosing central nervous system trypanosomiasis: two stage or not to stage
Ethical approval: Not required.
I appreciate Dr Armour’s comments and interest in my article in the Transactions.1 Clearly the fundi should always be examined in any neurological examination of a patient, and I would certainly hope that fundoscopy is always done in individuals with suspected sleeping sickness. While the eye can be rarely directly affected by the disease to cause such conditions as keratitis, choroidoretinitis and iridocyclitis, in a patient with central nervous system (CNS) sleeping sickness with developing raised intracranial pressure, the most likely fundal finding would probably be papilloedema, and if severe and acute that could also be accompanied by retinal haemorrhage. But I think that the other evidence for CNS involvement would probably be evident anyway in such a patient. However, whatever the clinical suspicion of CNS involvement, it is still not justified to treat a patient with melarsoprol or eflornithine without the diagnostic evidence of a CNS infection that is currently provided by examination of the cerebrospinal fluid by lumbar puncture. It is a pity that there are not currently reliable non-invasive methods of diagnosing late-stage sleeping sickness.
References
Funding: None.
Funding: None. Conflicts of interest: I am a director and small shareholder of Ophthalmos Ltd, a company that manufactures the Optyse lensfree ophthalmoscope.
1. Kennedy PGE. Diagnosing central nervous system trypanosomiasis: two stage or not to stage? Trans R Soc Trop Med Hyg 2008;102:306—7. 2. Lewallen S, Taylor TE, Molyneux ME, Wills BA, Courtright PH. Ocular fundus findings in Malawian children with cerebral malaria. Ophthalmology 1993;100:857—61. 3. Beare NAV, Taylor TE, Harding SP, Lewallen S, Molyneux ME. Malarial retinopathy: a newly established diagnostic sign in severe malaria. Am J Trop Med 2006;75:790—7. 4. Denniston A. Carbon monoxide poisoning and the eye. J R Soc Med 2001;94:425—6.
Conflicts of interest: None declared. Ethical approval: Not required.
Reference 1. Kennedy PGE. Diagnosing central nervous system trypanosomiasis: two stage or not to stage? Trans R Soc Trop Med Hyg 2008;102:306—7.
0035-9203/$ — see front matter © 2008 Royal Society of Tropical Medicine and Hygiene. Published by Elsevier Ltd. All rights reserved.
106
Correspondence
Peter G.E. Kennedy Division of Clinical Neurosciences, Faculty of Medicine, University of Glasgow, Institute of Neurological Science, Southern General Hospital, Glasgow G51 4TF, UK E-mail address: [email protected] 27 June 2008 Available online 9 August 2008 doi:10.1016/j.trstmh.2008.07.004
Comment on: Point-of-care testing for malaria outbreak management The point-of-care, one-step malaria test found to be efficient in the field on a remote island in Indonesia1 would be expected to alleviate several problems encountered during collection and transportation of pathological materials. The universal efficacy of the test in relation to microscopy for detection of Plasmodium spp. would be evident only at very high or low ambient temperatures. The point-of-care test is an immunological test involving an antigen—antibody reaction at optimal conditions, whilst microscopy involves staining and visual examination. At ambient temperatures around 10 ◦ C at 3000 m above sea level, lower temperatures would not alter the efficacy of any microscopic evaluation. Nevertheless, the performance of the immunochromatographic assay could be far from ideal. At extremes of temperatures, sick patients would be provided protective clothing: laboratory premises would be operative at ambient temperatures. Malaria has been common in the highlands of Western Kenya, from the valley bottom, to mid-hill and hilltop.2 Furthermore, higher ambient temperatures might selectively impair the quality of performance of the one-step malaria test, which would be possible in malaria-endemic deserts, including the Khatlon Region, a valley—desert landscape in the south of Tadjikistan.3 Meticulously planned investigations on similar lines1 are essential to confirm the universal competence of the malaria point-of-care test.
Sant Parmanand Hospital, 18 Alipore Road, Delhi 110054, India ∗
Corresponding author. E-mail address: [email protected] (S.C. Arya) Available online 28 August 2008 doi:10.1016/j.trstmh.2008.07.006
Reply to comment on: Point-of-care testing for malaria outbreak management The application of diagnostic assays such as the rapid point-of-care test for malaria that are based on immunological reactions could be limited by the environmental temperature at which the assay is performed. The purpose of our study1 was to determine the clinical utility of the rapid malaria test during an outbreak situation in Indonesia. The use of the rapid test under extremely hot conditions such as in desert areas may not be recommended, also because the devices, as mentioned in the publication, should be stored at 2—30 ◦ C. We have not tested the performance of the devices at low temperatures such as may prevail in malariaendemic high mountainous areas; whether or not the use of the devices at low temperature results in a lower signal intensity or even reduced sensitivity remains to be seen. Funding: None. Conflicts of interest: None declared. Ethical approval: Not required.
Reference 1. Ratnawati, Hatta M, Smits HL. Point-of-care testing for malaria outbreak management. Trans R Soc Trop Med Hyg 2008;102:699—704.
Funding: None. Henk L. Smits ∗ KIT Biomedical Research, Royal Tropical Institute/Koninklijk Instituut voor de Tropen (KIT), Meibergdreef 39, 1105 AZ Amsterdam, The Netherlands
Conflicts of interest: None declared. Ethical approval: Not required.
Reference
∗
1. Ratnawati, Hatta M, Smits HL. Point-of-care testing for malaria outbreak management. Trans R Soc Trop Med Hyg 2008;102:699—704. 2. Githeko AK, Ayisi JM, Odada PK, Atieli FK, Ndenga BA, Githure JI, et al. Topography and malaria transmission heterogeneity in western Kenya highlands: prospects for focal vector control. Malar J 2006;5:107. 3. Karimov SS, Kadamov DS, Murodova NKh. The current malaria situation in Tadjikistan [in Russian]. Med Parazitol (Mosk) 2008;(1):33—6.
Subhash C. Arya ∗ Nirmala Agarwal
Tel.: +31 20 566 5470; fax: +31 20 697 1841. E-mail address: [email protected] Available online 30 August 2008
doi:10.1016/j.trstmh.2008.07.010
Strongyloides stercoralis in the urine A 66-year-old man was diagnosed with hypopharyngeal cancer and received a combination of fluorouracil, cisplatin and corticosteroids. He was admitted to hospital for febrile neutropenia and was treated empirically with piperacillin/tazobactam. A diffuse infiltrate was detected on the chest radiograph. Respiratory failure and severe
available at www.sciencedirect.com
journal homepage: www.elsevierhealth.com/journals/trst
CORRESPONDENCE Comment on: Diagnosing central nervous system trypanosomiasis: two stage or not to stage In his scholarly review, Kennedy highlights both the therapeutic importance and the difficulty of differentiating the early or haemolymphatic stage of sleeping sickness from the late or encephalitic stage on clinical grounds.1 Similar difficulties were encountered in the case of cerebral malaria, especially in children in endemic areas, where parasitaemia is so common that it is not in itself diagnostic. And then Lewallen et al. described an unusual retinopathy seen on direct and indirect ophthalmoscopy in 57% of the patients.2 It has now been confirmed that retinal whitening, especially of the macula, and white or orange discoloration of retinal vessels are specific to malaria.3 Has fundoscopy through dilated pupils by trained practitioners been the subject of a clinical trial in patients with sleeping sickness? Might it help in the diagnosis of the encephalitic stage of the illness? Ophthalmologists and neurologists apart, most practitioners are not confident in the use of ophthalmoscopes, and fundoscopy is a muchneglected clinical method. As Denniston (2001) remarks, ‘‘Ophthalmoscopy is many a physician’s ‘blind spot’ . . .’’4
Roger Hanif Armour Lister Hospital, Stevenage, Hitchin, Hertfordshire, UK E-mail address: [email protected] 22 June 2008 Available online 9 August 2008 doi:10.1016/j.trstmh.2008.07.003
Reply to comment on: Diagnosing central nervous system trypanosomiasis: two stage or not to stage
Ethical approval: Not required.
I appreciate Dr Armour’s comments and interest in my article in the Transactions.1 Clearly the fundi should always be examined in any neurological examination of a patient, and I would certainly hope that fundoscopy is always done in individuals with suspected sleeping sickness. While the eye can be rarely directly affected by the disease to cause such conditions as keratitis, choroidoretinitis and iridocyclitis, in a patient with central nervous system (CNS) sleeping sickness with developing raised intracranial pressure, the most likely fundal finding would probably be papilloedema, and if severe and acute that could also be accompanied by retinal haemorrhage. But I think that the other evidence for CNS involvement would probably be evident anyway in such a patient. However, whatever the clinical suspicion of CNS involvement, it is still not justified to treat a patient with melarsoprol or eflornithine without the diagnostic evidence of a CNS infection that is currently provided by examination of the cerebrospinal fluid by lumbar puncture. It is a pity that there are not currently reliable non-invasive methods of diagnosing late-stage sleeping sickness.
References
Funding: None.
Funding: None. Conflicts of interest: I am a director and small shareholder of Ophthalmos Ltd, a company that manufactures the Optyse lensfree ophthalmoscope.
1. Kennedy PGE. Diagnosing central nervous system trypanosomiasis: two stage or not to stage? Trans R Soc Trop Med Hyg 2008;102:306—7. 2. Lewallen S, Taylor TE, Molyneux ME, Wills BA, Courtright PH. Ocular fundus findings in Malawian children with cerebral malaria. Ophthalmology 1993;100:857—61. 3. Beare NAV, Taylor TE, Harding SP, Lewallen S, Molyneux ME. Malarial retinopathy: a newly established diagnostic sign in severe malaria. Am J Trop Med 2006;75:790—7. 4. Denniston A. Carbon monoxide poisoning and the eye. J R Soc Med 2001;94:425—6.
Conflicts of interest: None declared. Ethical approval: Not required.
Reference 1. Kennedy PGE. Diagnosing central nervous system trypanosomiasis: two stage or not to stage? Trans R Soc Trop Med Hyg 2008;102:306—7.
0035-9203/$ — see front matter © 2008 Royal Society of Tropical Medicine and Hygiene. Published by Elsevier Ltd. All rights reserved.
106
Correspondence
Peter G.E. Kennedy Division of Clinical Neurosciences, Faculty of Medicine, University of Glasgow, Institute of Neurological Science, Southern General Hospital, Glasgow G51 4TF, UK E-mail address: [email protected] 27 June 2008 Available online 9 August 2008 doi:10.1016/j.trstmh.2008.07.004
Comment on: Point-of-care testing for malaria outbreak management The point-of-care, one-step malaria test found to be efficient in the field on a remote island in Indonesia1 would be expected to alleviate several problems encountered during collection and transportation of pathological materials. The universal efficacy of the test in relation to microscopy for detection of Plasmodium spp. would be evident only at very high or low ambient temperatures. The point-of-care test is an immunological test involving an antigen—antibody reaction at optimal conditions, whilst microscopy involves staining and visual examination. At ambient temperatures around 10 ◦ C at 3000 m above sea level, lower temperatures would not alter the efficacy of any microscopic evaluation. Nevertheless, the performance of the immunochromatographic assay could be far from ideal. At extremes of temperatures, sick patients would be provided protective clothing: laboratory premises would be operative at ambient temperatures. Malaria has been common in the highlands of Western Kenya, from the valley bottom, to mid-hill and hilltop.2 Furthermore, higher ambient temperatures might selectively impair the quality of performance of the one-step malaria test, which would be possible in malaria-endemic deserts, including the Khatlon Region, a valley—desert landscape in the south of Tadjikistan.3 Meticulously planned investigations on similar lines1 are essential to confirm the universal competence of the malaria point-of-care test.
Sant Parmanand Hospital, 18 Alipore Road, Delhi 110054, India ∗
Corresponding author. E-mail address: [email protected] (S.C. Arya) Available online 28 August 2008 doi:10.1016/j.trstmh.2008.07.006
Reply to comment on: Point-of-care testing for malaria outbreak management The application of diagnostic assays such as the rapid point-of-care test for malaria that are based on immunological reactions could be limited by the environmental temperature at which the assay is performed. The purpose of our study1 was to determine the clinical utility of the rapid malaria test during an outbreak situation in Indonesia. The use of the rapid test under extremely hot conditions such as in desert areas may not be recommended, also because the devices, as mentioned in the publication, should be stored at 2—30 ◦ C. We have not tested the performance of the devices at low temperatures such as may prevail in malariaendemic high mountainous areas; whether or not the use of the devices at low temperature results in a lower signal intensity or even reduced sensitivity remains to be seen. Funding: None. Conflicts of interest: None declared. Ethical approval: Not required.
Reference 1. Ratnawati, Hatta M, Smits HL. Point-of-care testing for malaria outbreak management. Trans R Soc Trop Med Hyg 2008;102:699—704.
Funding: None. Henk L. Smits ∗ KIT Biomedical Research, Royal Tropical Institute/Koninklijk Instituut voor de Tropen (KIT), Meibergdreef 39, 1105 AZ Amsterdam, The Netherlands
Conflicts of interest: None declared. Ethical approval: Not required.
Reference
∗
1. Ratnawati, Hatta M, Smits HL. Point-of-care testing for malaria outbreak management. Trans R Soc Trop Med Hyg 2008;102:699—704. 2. Githeko AK, Ayisi JM, Odada PK, Atieli FK, Ndenga BA, Githure JI, et al. Topography and malaria transmission heterogeneity in western Kenya highlands: prospects for focal vector control. Malar J 2006;5:107. 3. Karimov SS, Kadamov DS, Murodova NKh. The current malaria situation in Tadjikistan [in Russian]. Med Parazitol (Mosk) 2008;(1):33—6.
Subhash C. Arya ∗ Nirmala Agarwal
Tel.: +31 20 566 5470; fax: +31 20 697 1841. E-mail address: [email protected] Available online 30 August 2008
doi:10.1016/j.trstmh.2008.07.010
Strongyloides stercoralis in the urine A 66-year-old man was diagnosed with hypopharyngeal cancer and received a combination of fluorouracil, cisplatin and corticosteroids. He was admitted to hospital for febrile neutropenia and was treated empirically with piperacillin/tazobactam. A diffuse infiltrate was detected on the chest radiograph. Respiratory failure and severe