Cryptosporidiosis
Acute gastroenteritis associated with cryptosporidiosis in humans is in most cases self-limiting and symptoms disappear within a few days or weeks, but in very small number of cases the disease can be fatal.
We assumed that only a small proportion of cases (0.150%) experience the disease as more severe and complicated (Vijgen, 2007).
The average duration of the uncomplicated, mild disease is 3.5 days and 718.4 days for the complicated form (Vijgen, 2007).
The case fatality proportion was found to be 0.0042% (Vijgen, 2007), in line with 0.005% found in other studies (Mead, 1999). Mortality from acute gastroenteritis was assumed to be age-dependent and was redistributed according to the age-group-distributed cryptosporidiosis and giardiasis case fatality proportion reported to TESSy between 2009 and 2013 (see Table 3). This table is based on all TESSy notified cases from EEA Member States except Bulgaria, Poland (reporting only aggregate data), Austria, Czech Republic, Iceland, Luxembourg, Malta, Norway, Romania, Slovenia and Slovakia (because the very low incidence reported seems to indicate low sensitivity of the surveillance system).
Cryptosporidiosis can become chronic in immunocompromised persons, especially those with AIDS (Caccio and Pozio, 2006; Call, 2000; Pozio, 1997). However, several studies showed that AIDS-related cryptosporidiosis can be cured following successful antiretroviral therapy (Miao, 2000; Maggi, 2000; Foudraine, 1998).
Model input summary
Table 1. Transition probabilities and distributions used in the outcome tree
Health outcome |
Distribution of health states in health outcome |
Transition probability |
Source/assumption |
Symptomatic infection |
|
|
Vijgen, 2007 |
Uncomplicated) |
99.85% |
|
|
Complicated) |
0.15% |
|
|
Fatal cases following symptomatic infection |
|
0.0042% |
Vijgen, 2007; |
Table 2. Disability weights and duration
Health
outcome |
Disability Weight (DW) (Haagsma, 2015) |
Duration |
||
DW |
Label |
In years |
Source |
|
Symptomatic infection |
|
|
|
Vijgen, 2007 |
(Moderate) |
0.073 (0.0610.092) |
Diarrhoea, mild |
0.01 |
|
(Severe) |
0.239 (0.2020.285) |
Diarrhoea, severe |
0.0190.05 |
|
Table 3. Age-group redistribution of case fatality proportion due to cryptosporidiosis (0.0042%)
Age groups |
% |
0 |
12.50 |
14 |
6.25 |
59 |
6.25 |
1014 |
0.00 |
1519 |
0.00 |
2024 |
0.00 |
2529 |
0.00 |
3034 |
6.25 |
3539 |
0.00 |
4044 |
0.00 |
4549 |
6.25 |
5054 |
12.50 |
5559 |
6.25 |
6064 |
6.25 |
6569 |
6.25 |
7074 |
6.25 |
7579 |
18.75 |
8084 |
6.25 |
>85 |
0.00 |
All ages |
100.00 |
References
Caccio SM, Pozio E (2006). Advances in the epidemiology, diagnosis and treatment of cryptosporidiosis. Expert Rev Anti Infect Ther. 4(3):429-443.
Call SA, Heudebert G, Saag M, Wilcox CM (2000). The changing etiology of chronic diarrhea in HIV-infected patients with CD4 cell counts less than 200 cells/mm3. Am J Gastroenterol , 95(11):3142-3146.
Foudraine NA, Weverling GJ, van Gool T, Roos MT, de Wolf F, Koopmans PP, et al. (1998). Improvement of chronic diarrhoea in patients with advanced HIV-1 infection during potent antiretroviral therapy. Aids, 12(1):35-41.
Haagsma JA, Maertens de Noordhout C, Polinder S, Vos T, Havelaar AH, Cassini A, Devleesschauwer B, Kretzschmar ME, Speybroeck N, Salomon JA. Assessing disability weights based on the responses of 30,660 people from four European countries. Population Health Metrics 2015; 13: 10
Maggi P, Larocca AM, Quarto M, Serio G, Brandonisio O, Angarano G, et al. (2000) Effect of antiretroviral therapy on cryptosporidiosis and microsporidiosis in patients infected with human immunodeficiency virus type 1. Eur J Clin Microbiol Infect Dis, 19(3):213-217.
Mead PS, Slutsker L, Dietz V, McCaig LF, Bresee JS, Shapiro C, et al. (1999) Food-related illness and death in the United States. Emerg Infect Dis, 5(5):607-625.
Miao YM, Awad-El-Kariem FM, Franzen C, Ellis DS, Muller A, Counihan HM, et al. (2000) Eradication of cryptosporidia and microsporidia following successful antiretroviral therapy. J Acquir Immune Defic Syndr, 25(2):124-129.
Pozio E, Rezza G, Boschini A, Pezzotti P, Tamburrini A, Rossi P, et al. (1997) Clinical cryptosporidiosis and human immunodeficiency virus (HIV)-induced immunosuppression: findings from a longitudinal study of HIV-positive and HIV-negative former injection drug users. J Infect Dis, 176(4):969-975.
Vijgen SMC, Mangen MJM, Kortbeek LM, Van Duynhoven YTHP, Havelaar AH (2007). Disease burden and related costs of cryptosporidiosis and giardiasis in the Netherlands. 58 pp. Bilthoven.