Study in epidemiology and PCR detection of cryptosporidiosis in North of Baghdad

Other Title(s)

دراسة في الوبائية و التحري بتقنية لداء (PCR)‎ سلسلة تفاعل البلمره الأبواغ الخبيئة في شمال بغداد

Dissertant

al-Ward, Harith Said Jafar

Thesis advisor

Mahmud, Suhaylah Hayawi
al-Saqr, Ihsan Mahdi

Comitee Members

Yaqub, Alya Yusuf
al-Gilany, Ban A. A.
al-Hadithi, Ismail Abd al-Wahhab
al-Qazzaz, Abd al-Karim A.
al-Qadi, Ban Nuri

University

University of Baghdad

Faculty

College of Science

Department

Department of Biology

University Country

Iraq

Degree

Ph.D.

Degree Date

2010

English Abstract

Prevalence of cryptosporidiosis was studied in north of Baghdad, during the period from the beginning of April 2009 till the end of March 2010, in human and different water samples.

A total of 1235 samples have been tested from different origins: (737 human faecal samples, 240 tap water samples, 240 tank water sample and 18 river water samples).

Different factors were examined to be related with the prevalence of Cryptosporidiosis which were (gender , faecal status , age , occupation , family size , immunological status , travelling history , source of drinking water , weather temperature and presence of domestic animal in household) .

The study revealed that the total rate of infection in human being was 14.78%, and the peak of oocyst positive rates were seen during two months May and July 2009 which were 25.7% and 19.35% respectively , while the minimum rate was seen in November 2009 which was 9.76%.

noticed be No significant differences (p≤0.05) tween male and female as their rates of infection were 14.98% and 14.58% respectively.

Significant relation was observed between faecal status and the rate of infection, the percentage of positive case in diarrheal patients was higher than the non diarrheal patients who were 68.8% and 31.2% respectively.

Also high infection rate was recorded among children less than 10 years old which was 55.04 % when it compared with other age group , as well as preschool children and student were observed to be the majority groups that infected with Cryptosporidium which were 45.8% and 18.3% respectively and when they compared with housewives and unemployed persons , these results indicated that there were significant relations (p≤0.05) between occupation and rate of infection , similar results were observed in persons belonged to high family member especially family composed of (15-19 members) ,the rate of infection was 28.32% when it compared with 10.77 % in patients belonged to family composed of (less than 5 members) .

Other significant relations (p≤0.05) were noticed with immunological status and travelling history, the rate of infection was highest in immune-compromised patients 78.12% than immune-competent patients 11.91%, and also it was higher in patients with travelling history 38.8%, than patient without travelling history 14.81%.

Source of drinking water also played an important role in prevalence of cryptosporidiosis, persons who consumed boiled water showed the minimum rate of infection which was 5% when it compared with other persons who consumed tap, filtered and bottled water, these results were in parallel with other results of water examination.

All tap water samples were free of Cryptosporidium , while it was detected in tank and river water samples .

The most surprising results, that there was no significant relation between the presence of domestic animals and rate of infection, although it was higher in patients who had domestic animals in their household 19.49% than those who had no domestic animals in their household 13.89%.

In addition to microscopic examination for each faecal and water samples the PCR technique was used to determine the presence of Cryptosporidium specific gene locus in the extracted DNA which were extracted by a modified protocol , 15 cycles freezing-thawing in liquid nitrogen was more efficient than only three cycles by deep freeze in facilitate the subsequent steps of DNA extraction , SSU rRNA–based PCR-detecting tools have been successfully used in the detection of Cryptosporidium oocysts in high intensity faecal sample and surface-water samples (intensity of oocysts is highly related with amplicon production), while it is not recommended in low intensity samples.

On other hand experimental infection was established in immunosupreesed and non-immunosupressed mice using two different Cryptosporidium spp.

isolates : faecal origin and water origin , then the infectivity rate , cellular immunological status and histopathological changes were examined in these groups of mice , results indicated that these two isolates were able to induce experimental infection in immunosuppressed and non-immunosuppressed mice , and the oocyst shedding may not indicate the severity of illness like histopathological changes which indicated strongly the level of infection which were more severe in immunosuppressed mice and low or moderate in non immunosuppressed mice and these changes may correlate with transformed lymphocyte and phagocytic ndex.

Main Subjects

Medicine

Topics

• Epidemiology
• Iraq

No. of Pages

166

Table of Contents

• APA
• MLA
• AMA

Language

English

Data Type

Arab Theses

Record ID

BIM-598435