Dispatches
Cryptosporidiosis, whether it is more prevalent in Southern India Harmesh Manocha, Seema Dua1, Yogesh Chander, Megha Tailang Departments of Microbiology, and 1Pathology, School of Medical Sciences and Research, Knowledge Park III, Greater Noida, Uttar Pradesh, India
ABSTRACT
KEY WORDS Cryptosporidiosis, prevalence, oocyst
Cryptosporidium species is identified as an important cause of morbidity in children and adults. Prevalence rate as reported from various studies in India is much lower when compared to developed word. Present study was designed to analyze the prevalence of cryptosporidiosis in West Godavari District, Andhra Pradesh. Stool samples from 306 patients suffering with gastrointestinal symptoms were examined for the presence of Cryptosporidium oocysts. A higher prevalence (25%) was found when compared to reports from north east and western India. Cryptosporidium was prevalent in 35-36% of adults, 17% of children and 20% of infants.
THE STUDY Cryptosporidium reported by Tyzzer in 1907 [1] and well‑known to veterinarians since 1953, has gained recognition as a human pathogen since 1976.[2] The acquired immune deficiency syndrome pandemic has brought Cryptosporidium to the forefront as an important pathogen in immunocompromised persons.[3,4] Cryptosporidium species is now commonly identified in cases of acute, self‑limited diarrheal illness in immunocompetent hosts in both developed [5,6] and developing [7,8] nations. The seroprevalence of Cryptosporidium among patients suffering with diarrhea is reported as high as 90% from Brazil and 50% from China.[9] In the developing world, the association of Cryptosporidium with both acute and persistent diarrhea among immunocompetent children has been reported as Address for correspondence Dr. Harmesh Manocha, Department of Microbiology, School of Medical Sciences and Research, Knowledge Park III, Greater Noida ‑ 201 306, Uttar Pradesh, India. E‑mail: [email protected] Access this article online Quick Response Code:
Website: www.tropicalparasitology.org DOI: 10.4103/2229-5070.138543
Tropical Parasitology
29.6%.[10] On the other hand, the prevalence as reported from India is low e.g., 1.3% from Northern India,[11] 4.5% from the eastern part of the country (West Bengal),[12] 5.5% from South to West (Mumbai)[13] and 13.1% from South India. [14] In a recent study from Hyderabad prevalence was reported to be as low as 2.99% in children and 0.12% in adults.[15] The present study was designed to assess the prevalence of cryptosporidiosis among cases from West Godavari district. Patients belonging to West Godavari district suffering from diarrhea or other gastrointestinal symptoms who attended ASRAM Hospital, ELURU from November 2006 to October 2007 were included in the present study. Study population included both out‑patients and inpatients from different clinical departments selected on random bases. Permission was taken from Institutional Human Ethical Committee for commission of this study. All the stool samples were examined using saline and iodine wet mounts for the presence of protozoal cysts, trophozoites, helminthic ova, larvae, pus cells, macrophages and red blood cells. For detection of Cryptosporidium oocysts, samples were concentrated by Sheather sucrose floatation method.[16] Smears prepared from concentrated samples were fixed, air‑dried and stained with modified Ziehl‑Neelsen method (Kinyoun stain).[17] Oval or round acid fast bodies (dark pink) 4‑5 µm in size were taken as oocysts of Cryptosporidium. All slides were examined by two observers. All the patients carrying Cryptosporidium 125
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Manocha, et al.: Cryptosporidiosis in Southern India
oocyst in their stool samples were also subjected to human immunodeficiency virus (HIV) screening test. The socio‑economic status was evaluated based on Kuppuswamy’s socio‑economic status scale‑updating for 2007[18] with a little modification that instead of dividing study population into five groups we divided it into three groups by merging upper and upper middle into high and upper lower and lower in low socio‑economic group.
age matched controls.[14] Reports from West Bengal and Mumbai showed the parasite to be prevalent in 4.45% and 5.5% of children with diarrhea respectively.[12,13] A lower prevalence rate of 1.3% was reported from North India.[11] In the present study, Cryptosporidium was prevalent in 35-36% of adults 17% of children and 20% of infants. It seems that these parasites have a tendency to colonization in adults. We could not find any positive case in the age group 5‑12 year and 12‑18 years. The reason may be that only a small no of cases (total 36) attended the hospital in this age group. 11 cases positive for Cryptosporidium oocyst were also positive for HIV. This finding is in favor of the previous reports that Cryptosporidium is an opportunistic pathogen.
A total of 306 samples could be collected (192 males and 114 females). Out of 306 cases 15% (45/306) were in the age group 0‑1 year, 19% (58/306) in the age group 1‑5 year, 02% (6/306) in 5‑12 year, 10% (30/306) in 12‑18 year, 38% (117/306) in 18‑40 year and 16% (50/306) in >40 years. 27% patients (84/306) were positive for one or more parasites. Oocysts of Cryptosporidium spp. were detected in 25% (78/306) patients. ([Adults 76% [59/78], Children 13% [10/78] and Infants 11% [9/78]]). Prevalence in the age group 0‑1 year was 20% (9/45), in 1‑5 year 17% (10/58), in 18‑40 year 35% (41/117) and above 40 it was 36% (18/50). We could not detect Cryptosporidium in the age group 5‑12 and 5‑18 year. Out of 78 cases positive for cryptosporidium oocyst, 69% (54/78) were males and 31% (24/78) were females. Prevalence in male was 28% (54/192) and in females it was 21% (24/114). Among all the cases included in the study, 180 were from low, 90 from middle and 36 from high socio‑economic group. The prevalence rate was 27% (48/180) in low, 20% (18/90) in the middle and 33% (12/36) in high socio‑economic group. Out of 78 cases positive for cryptosporidium 11 were positive for HIV by the screening test (HIV Tridot, J. Mitra and Co Pvt. Ltd.). Other parasites detected were Isospora belli 5% (14/306), Taenia spp. 3% (9/306), Strongyloides stercoralis 2% (5/306) and Entamoeba histolytica 1% (3/306). Co‑infection was found in 8% (24/306) cases (Cryptosporidium with Taenia spp. 2% [6/306], Cryptosporidium with I. belli 4% [13/306] and Cryptosporidium with I. belli and S. stercoralis 2% [5/306]).
We conclude that the prevalence of Cryptosporidium among cases suffering with diarrhea is remarkably high in India at least in the southern part of the country. In our study, we examined concentrated samples for detection of Cryptosporidium oocyst. It may have contributed to a higher rate of detection. The difference in prevalence in various socio‑economic groups was statistically not significant. (P = 0.256). The prevalence in male and female was also statistically not significant (P = 0.113). All the findings so far reported are from hospital based studies. In spite of the increasing numbers of HIV infected patients and low standards of sanitation in the country, which predispose to Cryptosporidium infection, awareness regarding the disease continues to be low among microbiologists and clinicians. In order to understand the as yet undefined host parasite interaction, genetic and epidemiologic characterization of the neglected protozoon parasite Cryptosporidium, is needed. ACKNOWLEDGMENT The authors would like to thank all faculty members and other staff, Department of Microbiology, Alluri Sitarama Raju Academy of Medical Sciences, Eluru, Andhra Pradesh, India.
CONCLUSIONS
REFERENCES
Prevalence of human cryptosporidiosis varies widely in different parts of the world. Recurrent Cryptosporidium infection and relapsing diarrhea associated with it was found to be common in North Eastern Brazil.[19] A review of 78 reports showed Cryptosporidium infection in immunocompetent persons with diarrhea in 2.1% of industrialized and 6.1% of developing countries respectively.[20] Seroprevalence is much higher. 50% of children in China and more than 90% of children in Brazil had serologic evidence of cryptosporidial infection.[9] In the developing countries, the disease is endemic.[7,8] In India, the reported prevalence differs in various part of the country. In South India, Cryptosporidium spp. was detected in 13.1% of children with diarrhea and 9.1% of
1.
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2.
3. 4. 5. 6.
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Tyzzer EE. A sporozoan found in the peptic glands of the common mouse. Proc Soc Exp Biol Med 1907;5:12‑3. Nime FA, Burek JD, Page DL, Holscher MA, Yardley JH. Acute enterocolitis in a human being infected with the protozoan cryptosporidium. Gastroenterology 1976;70:592‑8. Janoff EN, Reller LB. Cryptosporidium species, a protean protozoan. J Clin Microbiol 1987;25:967‑75. Guarda LA, Stein SA, Cleary KA, Ordóñez NG. Human cryptosporidiosis in the acquired immune deficiency syndrome. Arch Pathol Lab Med 1983;107:562‑6. Hunt DA, Shannon R, Palmer SR, Jephcott AE. Cryptosporidiosis in an urban community. Br Med J (Clin Res Ed) 1984;289:814‑6. Wolfson JS, Richter JM, Waldron MA, Weber DJ, McCarthy DM, Hopkins CC. Cryptosporidiosis in Tropical Parasitology
Manocha, et al.: Cryptosporidiosis in Southern India
immunocompetent patients. N Engl J Med 1985;312:1278‑82. 7. Bogaerts J, Lepage P, Rouvroy D, Vandepitte J. Cryptosporidium spp., a frequent cause of diarrhea in Central Africa. J Clin Microbiol 1984;20:874‑6. 8. Mata L, Bolaños H, Pizarro D, Vives M. Cryptosporidiosis in children from some highland Costa Rican rural and urban areas. Am J Trop Med Hyg 1984;33:24‑9. 9. Zu SX, Li JF, Barrett LJ, Fayer R, Shu SY, McAuliffe JF, et al. Seroepidemiologic study of Cryptosporidium infection in children from rural communities of Anhui, China and Fortaleza, Brazil. Am J Trop Med Hyg 1994;51:1‑10. 10. M i l l e r K , D u r a n ‑ P i n a l e s C , C r u z ‑ L o p e z A , Morales‑Lechuga L, Taren D, Enriquez FJ. Cryptosporidium parvum in children with diarrhea in Mexico. Am J Trop Med Hyg 1994;51:322‑5. 11. Sethi S, Sehgal R, Malla N, Mahajan RC. Cryptosporidiosis in a tertiary care hospital. Natl Med J India 1999;12:207‑9. 12. Das P, Pal S, Dutta D, Bhattacharya MK, Pal SC. Cryptosporidiosis in Bengali children with acute diarrhoea. Trans R Soc Trop Med Hyg 1987;81:241. 13. Saraswathi K, Pandit DV, Deodhar LP, Bichile LS. Prevalence of cryptosporidia in patients with diarrhoea in Bombay. Indian J Med Res 1988;87:221‑4. 14. Mathan MM, Venkatesan S, George R, Mathew M, Mathan VI. Cryptosporidium and diarrhoea in southern Indian children. Lancet 1985;2:1172‑5.
Tropical Parasitology
15. Nagamani K, Rajkumari A, Gyaneshwari. Cryptosporidiosis in a tertiary care hospital in Andhra Pradesh. Indian J Med Microbiol 2001;19:215‑6. 16. Collee JG, Fraser AG, Mackie and McCartney Practical Medical Microbiology.14 th ed. Edinburgh london: Churchil Livingstone; 1999. p. 743. 17. Forbs BA, Daniel FS, Alice SW. Bailey and Scott’s Diagnostic Microbiology. 12th ed. St Louis Missouri: Mosby Elsevier; 2007. 18. Kumar N, Shekhar C, Kumar P, Kundu AS. Kuppuswamy’s socioeconomic status scale‑updating for 2007. Indian J Pediatr 2007;74:1131‑2. 19. Newman RD, Sears CL, Moore SR, Nataro JP, Wuhib T, Agnew DA, et al. Longitudinal study of Cryptosporidium infection in children in northeastern Brazil. J Infect Dis 1999;180:167‑75. 20. Guerrant RL. Cryptosporidiosis: An emerging, highly infectious threat. Emerg Infect Dis 1997;3:51‑7.
How to cite this article: Manocha H, Dua S, Chander Y, Tailang M. Cryptosporidiosis, whether it is more prevalent in Southern India. Trop Parasitol 2014;4:125-7. Source of Support: Department of Microbiology, Alluri Sitarama Raju Academy of Medical Sciences, Eluru, Andhra Pradesh, India, provided laboratory reagents, technical man power and equipment’s, Conflict of Interest: None declared. DOA: 18-10-2013, DOP: ***
127
Jul 2014 | Volume 4 | Issue 2 |
Copyright of Tropical Parasitology is the property of Medknow Publications & Media Pvt. Ltd. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use.
Cryptosporidiosis, whether it is more prevalent in Southern India Harmesh Manocha, Seema Dua1, Yogesh Chander, Megha Tailang Departments of Microbiology, and 1Pathology, School of Medical Sciences and Research, Knowledge Park III, Greater Noida, Uttar Pradesh, India
ABSTRACT
KEY WORDS Cryptosporidiosis, prevalence, oocyst
Cryptosporidium species is identified as an important cause of morbidity in children and adults. Prevalence rate as reported from various studies in India is much lower when compared to developed word. Present study was designed to analyze the prevalence of cryptosporidiosis in West Godavari District, Andhra Pradesh. Stool samples from 306 patients suffering with gastrointestinal symptoms were examined for the presence of Cryptosporidium oocysts. A higher prevalence (25%) was found when compared to reports from north east and western India. Cryptosporidium was prevalent in 35-36% of adults, 17% of children and 20% of infants.
THE STUDY Cryptosporidium reported by Tyzzer in 1907 [1] and well‑known to veterinarians since 1953, has gained recognition as a human pathogen since 1976.[2] The acquired immune deficiency syndrome pandemic has brought Cryptosporidium to the forefront as an important pathogen in immunocompromised persons.[3,4] Cryptosporidium species is now commonly identified in cases of acute, self‑limited diarrheal illness in immunocompetent hosts in both developed [5,6] and developing [7,8] nations. The seroprevalence of Cryptosporidium among patients suffering with diarrhea is reported as high as 90% from Brazil and 50% from China.[9] In the developing world, the association of Cryptosporidium with both acute and persistent diarrhea among immunocompetent children has been reported as Address for correspondence Dr. Harmesh Manocha, Department of Microbiology, School of Medical Sciences and Research, Knowledge Park III, Greater Noida ‑ 201 306, Uttar Pradesh, India. E‑mail: [email protected] Access this article online Quick Response Code:
Website: www.tropicalparasitology.org DOI: 10.4103/2229-5070.138543
Tropical Parasitology
29.6%.[10] On the other hand, the prevalence as reported from India is low e.g., 1.3% from Northern India,[11] 4.5% from the eastern part of the country (West Bengal),[12] 5.5% from South to West (Mumbai)[13] and 13.1% from South India. [14] In a recent study from Hyderabad prevalence was reported to be as low as 2.99% in children and 0.12% in adults.[15] The present study was designed to assess the prevalence of cryptosporidiosis among cases from West Godavari district. Patients belonging to West Godavari district suffering from diarrhea or other gastrointestinal symptoms who attended ASRAM Hospital, ELURU from November 2006 to October 2007 were included in the present study. Study population included both out‑patients and inpatients from different clinical departments selected on random bases. Permission was taken from Institutional Human Ethical Committee for commission of this study. All the stool samples were examined using saline and iodine wet mounts for the presence of protozoal cysts, trophozoites, helminthic ova, larvae, pus cells, macrophages and red blood cells. For detection of Cryptosporidium oocysts, samples were concentrated by Sheather sucrose floatation method.[16] Smears prepared from concentrated samples were fixed, air‑dried and stained with modified Ziehl‑Neelsen method (Kinyoun stain).[17] Oval or round acid fast bodies (dark pink) 4‑5 µm in size were taken as oocysts of Cryptosporidium. All slides were examined by two observers. All the patients carrying Cryptosporidium 125
Jul 2014 | Volume 4 | Issue 2 |
Manocha, et al.: Cryptosporidiosis in Southern India
oocyst in their stool samples were also subjected to human immunodeficiency virus (HIV) screening test. The socio‑economic status was evaluated based on Kuppuswamy’s socio‑economic status scale‑updating for 2007[18] with a little modification that instead of dividing study population into five groups we divided it into three groups by merging upper and upper middle into high and upper lower and lower in low socio‑economic group.
age matched controls.[14] Reports from West Bengal and Mumbai showed the parasite to be prevalent in 4.45% and 5.5% of children with diarrhea respectively.[12,13] A lower prevalence rate of 1.3% was reported from North India.[11] In the present study, Cryptosporidium was prevalent in 35-36% of adults 17% of children and 20% of infants. It seems that these parasites have a tendency to colonization in adults. We could not find any positive case in the age group 5‑12 year and 12‑18 years. The reason may be that only a small no of cases (total 36) attended the hospital in this age group. 11 cases positive for Cryptosporidium oocyst were also positive for HIV. This finding is in favor of the previous reports that Cryptosporidium is an opportunistic pathogen.
A total of 306 samples could be collected (192 males and 114 females). Out of 306 cases 15% (45/306) were in the age group 0‑1 year, 19% (58/306) in the age group 1‑5 year, 02% (6/306) in 5‑12 year, 10% (30/306) in 12‑18 year, 38% (117/306) in 18‑40 year and 16% (50/306) in >40 years. 27% patients (84/306) were positive for one or more parasites. Oocysts of Cryptosporidium spp. were detected in 25% (78/306) patients. ([Adults 76% [59/78], Children 13% [10/78] and Infants 11% [9/78]]). Prevalence in the age group 0‑1 year was 20% (9/45), in 1‑5 year 17% (10/58), in 18‑40 year 35% (41/117) and above 40 it was 36% (18/50). We could not detect Cryptosporidium in the age group 5‑12 and 5‑18 year. Out of 78 cases positive for cryptosporidium oocyst, 69% (54/78) were males and 31% (24/78) were females. Prevalence in male was 28% (54/192) and in females it was 21% (24/114). Among all the cases included in the study, 180 were from low, 90 from middle and 36 from high socio‑economic group. The prevalence rate was 27% (48/180) in low, 20% (18/90) in the middle and 33% (12/36) in high socio‑economic group. Out of 78 cases positive for cryptosporidium 11 were positive for HIV by the screening test (HIV Tridot, J. Mitra and Co Pvt. Ltd.). Other parasites detected were Isospora belli 5% (14/306), Taenia spp. 3% (9/306), Strongyloides stercoralis 2% (5/306) and Entamoeba histolytica 1% (3/306). Co‑infection was found in 8% (24/306) cases (Cryptosporidium with Taenia spp. 2% [6/306], Cryptosporidium with I. belli 4% [13/306] and Cryptosporidium with I. belli and S. stercoralis 2% [5/306]).
We conclude that the prevalence of Cryptosporidium among cases suffering with diarrhea is remarkably high in India at least in the southern part of the country. In our study, we examined concentrated samples for detection of Cryptosporidium oocyst. It may have contributed to a higher rate of detection. The difference in prevalence in various socio‑economic groups was statistically not significant. (P = 0.256). The prevalence in male and female was also statistically not significant (P = 0.113). All the findings so far reported are from hospital based studies. In spite of the increasing numbers of HIV infected patients and low standards of sanitation in the country, which predispose to Cryptosporidium infection, awareness regarding the disease continues to be low among microbiologists and clinicians. In order to understand the as yet undefined host parasite interaction, genetic and epidemiologic characterization of the neglected protozoon parasite Cryptosporidium, is needed. ACKNOWLEDGMENT The authors would like to thank all faculty members and other staff, Department of Microbiology, Alluri Sitarama Raju Academy of Medical Sciences, Eluru, Andhra Pradesh, India.
CONCLUSIONS
REFERENCES
Prevalence of human cryptosporidiosis varies widely in different parts of the world. Recurrent Cryptosporidium infection and relapsing diarrhea associated with it was found to be common in North Eastern Brazil.[19] A review of 78 reports showed Cryptosporidium infection in immunocompetent persons with diarrhea in 2.1% of industrialized and 6.1% of developing countries respectively.[20] Seroprevalence is much higher. 50% of children in China and more than 90% of children in Brazil had serologic evidence of cryptosporidial infection.[9] In the developing countries, the disease is endemic.[7,8] In India, the reported prevalence differs in various part of the country. In South India, Cryptosporidium spp. was detected in 13.1% of children with diarrhea and 9.1% of
1.
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2.
3. 4. 5. 6.
126
Tyzzer EE. A sporozoan found in the peptic glands of the common mouse. Proc Soc Exp Biol Med 1907;5:12‑3. Nime FA, Burek JD, Page DL, Holscher MA, Yardley JH. Acute enterocolitis in a human being infected with the protozoan cryptosporidium. Gastroenterology 1976;70:592‑8. Janoff EN, Reller LB. Cryptosporidium species, a protean protozoan. J Clin Microbiol 1987;25:967‑75. Guarda LA, Stein SA, Cleary KA, Ordóñez NG. Human cryptosporidiosis in the acquired immune deficiency syndrome. Arch Pathol Lab Med 1983;107:562‑6. Hunt DA, Shannon R, Palmer SR, Jephcott AE. Cryptosporidiosis in an urban community. Br Med J (Clin Res Ed) 1984;289:814‑6. Wolfson JS, Richter JM, Waldron MA, Weber DJ, McCarthy DM, Hopkins CC. Cryptosporidiosis in Tropical Parasitology
Manocha, et al.: Cryptosporidiosis in Southern India
immunocompetent patients. N Engl J Med 1985;312:1278‑82. 7. Bogaerts J, Lepage P, Rouvroy D, Vandepitte J. Cryptosporidium spp., a frequent cause of diarrhea in Central Africa. J Clin Microbiol 1984;20:874‑6. 8. Mata L, Bolaños H, Pizarro D, Vives M. Cryptosporidiosis in children from some highland Costa Rican rural and urban areas. Am J Trop Med Hyg 1984;33:24‑9. 9. Zu SX, Li JF, Barrett LJ, Fayer R, Shu SY, McAuliffe JF, et al. Seroepidemiologic study of Cryptosporidium infection in children from rural communities of Anhui, China and Fortaleza, Brazil. Am J Trop Med Hyg 1994;51:1‑10. 10. M i l l e r K , D u r a n ‑ P i n a l e s C , C r u z ‑ L o p e z A , Morales‑Lechuga L, Taren D, Enriquez FJ. Cryptosporidium parvum in children with diarrhea in Mexico. Am J Trop Med Hyg 1994;51:322‑5. 11. Sethi S, Sehgal R, Malla N, Mahajan RC. Cryptosporidiosis in a tertiary care hospital. Natl Med J India 1999;12:207‑9. 12. Das P, Pal S, Dutta D, Bhattacharya MK, Pal SC. Cryptosporidiosis in Bengali children with acute diarrhoea. Trans R Soc Trop Med Hyg 1987;81:241. 13. Saraswathi K, Pandit DV, Deodhar LP, Bichile LS. Prevalence of cryptosporidia in patients with diarrhoea in Bombay. Indian J Med Res 1988;87:221‑4. 14. Mathan MM, Venkatesan S, George R, Mathew M, Mathan VI. Cryptosporidium and diarrhoea in southern Indian children. Lancet 1985;2:1172‑5.
Tropical Parasitology
15. Nagamani K, Rajkumari A, Gyaneshwari. Cryptosporidiosis in a tertiary care hospital in Andhra Pradesh. Indian J Med Microbiol 2001;19:215‑6. 16. Collee JG, Fraser AG, Mackie and McCartney Practical Medical Microbiology.14 th ed. Edinburgh london: Churchil Livingstone; 1999. p. 743. 17. Forbs BA, Daniel FS, Alice SW. Bailey and Scott’s Diagnostic Microbiology. 12th ed. St Louis Missouri: Mosby Elsevier; 2007. 18. Kumar N, Shekhar C, Kumar P, Kundu AS. Kuppuswamy’s socioeconomic status scale‑updating for 2007. Indian J Pediatr 2007;74:1131‑2. 19. Newman RD, Sears CL, Moore SR, Nataro JP, Wuhib T, Agnew DA, et al. Longitudinal study of Cryptosporidium infection in children in northeastern Brazil. J Infect Dis 1999;180:167‑75. 20. Guerrant RL. Cryptosporidiosis: An emerging, highly infectious threat. Emerg Infect Dis 1997;3:51‑7.
How to cite this article: Manocha H, Dua S, Chander Y, Tailang M. Cryptosporidiosis, whether it is more prevalent in Southern India. Trop Parasitol 2014;4:125-7. Source of Support: Department of Microbiology, Alluri Sitarama Raju Academy of Medical Sciences, Eluru, Andhra Pradesh, India, provided laboratory reagents, technical man power and equipment’s, Conflict of Interest: None declared. DOA: 18-10-2013, DOP: ***
127
Jul 2014 | Volume 4 | Issue 2 |
Copyright of Tropical Parasitology is the property of Medknow Publications & Media Pvt. Ltd. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use.
