Predictors of intestinal parasitosis in school children of Kashmir : A prospective study

Intestinal parasitic infestations have a very high prevalence in tropical and subtropical countries and the populations face substantial morbidity on this account.[1] Ascariasis lumbricoides and Enterobius vermicularis are the most common species affecting humans. Ankylostoma duodenale and Trichuris trichura, Taenia saginata and Taenia solium are other common cestodes.[2] Figures from Center for Disease Control and Prevention (CDC) on Intestinal Surveillance Programme in USA revealed the presence of parasitic forms in 64,901 (15.6%) of over 400,000 stool samples examined.[3] Data on the prevalence and other parasite and host related factors are fundamental to planning any rational control or eradication programme for parasites in human populations. Children being more prone and a high risk group deserve special attention. We were prompted to undertake this epidemiological study to identify factors associated with intestinal parasitosis in school going children. The aim was to study the prevalence and pattern of intestinal parasitosis in school children of Kashmir valley both from rural and urban areas and to determine the association of various social and demographic parameters with the prevalence of parasitism.

Materials and methods

The current study was conducted in the department of Gastroenterology, SKIMS, Srinagar , a tertiary care center in north Indian state of Jammu & Kashmir. Stool samples were collected from children studying in schools and orphanages and cluster sampling was done in urban (Srinagar city) and in rural areas (Baramulla district) from Jan 2002 to Dec 2003.

In the present study various demographic and social characteristics were considered like source of drinking water viz., tap water, well water and river/stream water and the type of toilet facility available viz, temporary or pit, flush or open defecation. The study population was stratified as per the Kuppaswamy social scale .The visiting doctor categorized students as having poor personal hygiene and good personal hygiene depending upon length of nails and whether hair was trimmed nicely and the frequency of bathing. Based on a proforma complete demographic details were recorded.

Examination of stool for protozoal infections

Microscopic examination of stool was done under low and high power in unstained preparation for typical parasitic movement and stained preparations (Iodine staining) were used for nuclear details.

For helminthic infections

Microscopic examination:- A thin smear as large as 1½”x1" was made on 3" x 1" glass slide covered with a cover-slip and examined under the microscope. Floatation technique either with saline or with zinc sulphate centrifugal floatation or sedimentation techniques were used by the investigators if the egg count was low.

Statistical analysis: Data was entered in SPSS and univariate analysis was done. Chi-square test was used for categorical variables and Student’s t test for continuous variable with normal distribution. p value of <0.05 was considered as significant.

Results

Of 514 stool samples, 218 cases were positive for parasitosis i.e. positive prevalence of 42.41%. 274 samples were from rural children while 240 samples were from urban school children. Prevalence of ascariasis was highest. 146 cases were positive for ascariasis i.e., 28% prevalence, this was followed by 7% positive prevalence of Giardiasis. The positive prevalence of Trichuriasis and Taeniasis were 5% and 4% respectively. 2.5% of study population had double parasitosis. Parasitosis was higher in males (51%) than in females (41%); (p< 0.05) .The male female ratio was 133/124 =1.07:1. As shown in Table 1 parasitosis was higher in students with lower social economic and maximum parasitosis was seen in age group of 8-11years.

Water source: Significantly higher prevalence of intestinal parasitism was seen in children who drank river/stream water compared to those where tap water and well water was main source of water 25/44(56.82%)vs. 36/88(40.9%)[ p value < 0.05]. (Table2)

Type of Toilet facility: Parasitosis was significantly higher in those children who would go for open defecation compared to those children who used flush and pit.[ p <0.05]. (Table3) Personal hygiene: 202 of 274 rural children had dirty/ untrimmed nails and prevalence of parasitosis was high (58%) amongst those with dirty nails as compared to 21% among those with clean nails (p < 0.05). 53 of 240 urban children had dirty nails and a positive prevalence of parasitosis was 53%. (p < 0.05).

Rural /urban habitat: prevalence of parasitosis was higher in children from rural orphanage than urban orphanage. Of fifty male children included from rural orphanage (Bandipora), 38 stool samples were positive, i.e. a positive prevalence of 76%, and of 50 males, 24 stool samples were positive from urban orphanage (Srinagar), i.e. positive prevalence of 48% (p < 0.05).

Discussion

Human parasitism is a global problem of enormous proportion. The prevalence rates of intestinal parasites exhibit wide variation from country to country; between geographic areas, communities and ethnic groups even seasonal variations are also known.[4] Previous studies have shown that crowding and technical problems in disposal of sewage as the main factors determining parasitosis.[5] Our study indicated that personal hygiene, water source and type of the toilet facility as important factors associated with intestinal parasitosis in children, giving higher prevalence rates among rural poor . Globally, however, trend is changing as due to rural-urban migration world over, development of overcrowded and insanitary slums act as new foci for the transmission of infectious diseases. Thus, if the current mass migration of the rural poor into the urban areas continues, there is bound to be a heavy increase in the prevalence of geohelminth infection on a global scale. In the present study, an attempt was made to see any link between the source of drinking water and the presence of intestinal parasites, a high positive prevalence was observed among children whose source of drinking water was river/stream. These results are in accordance with the reports by Singh et al,[6] who considered the source and unsatisfactory storage of drinking water as one of the predictors of high intestinal parasitism. Thus, the present study indicates that the source of drinking water could be one of the factors associated with the prevalence of intestinal parasitism along with poor environmental sanitation and unhygienic conditions. This leads to a public health hazard which is threatening the developing countries and should be an eye opener for the public health planners. Indices of poor sanitation are important predictors of intestinal parasitism, this is evident from the results of the present study where in a high percentage prevalence of 68% was seen in children who defecated in the open, compared to a low percentage prevalence of 50% and 34% among children who used a pit or flush for defecation. These results also tally with the reports of Singh et al,[6] who reported a higher prevalence of parasitism among children going for open fielddefecation as compared to those using sanitary type of latrines. Positive associations between open defecation and higher nematode infections have been noted by other studies as well.[7,8,9,10,11] In a door to door survey conducted by De Silva et al,[12] authors observed that in the municipal civil lines there was a high percentage prevalence of parasitism as compared to those in the model tenements. In the municipal civil lines there were only about 80 latrines for the use of about 6,000 individuals, as a result the children were forced to defecate in the open whereas in the model tenement each latrine was shared by 2-3 families, this could be a probable reason for the high prevalence of parasitism in the children residing in the Municipal civil lines. Sanitary conditions are important predictors of intestinal parasitism. From the present study, it was evident that children with better personal hygiene had a fewer rate of intestinal parasitic infestations. Urbanization has brought about greater awareness about better personal hygiene. The percentage prevalence was comparatively low among the urban children with clean nails as compared to those with dirty nails. Other workers[13,14] have also established a direct relationship between poor sanitation and personal hygiene with prevalence of intestinal parasitism. Kang et al[15] studied the prevalence of intestinal parasitoses in rural southern Indians and observed that overall parasitic infestations were 97.4%. There results could be explained by the fact that authors had studied multiple samples from each study subject which would have increased the parasite detection rate. They concluded that asymptomatic individuals could be infrequent or frequent excretors, indicating that the host response may be the determining factor in parasitic replication in gut. Ascariasis was the most common parasitic infestation in our study while as in their study hook worm infestation was most common. The complex interplay between agent and environment must be important determinant in determining the type of parasitosis in a given geographical area besides personal hygiene.

Conclusions

From our observations, we have definite suggestions to reaffirm and strengthen the concepts that poor environmental sanitation, personal hygiene, low socio-economic status are closely interwoven and reflect a poor quality of social life. This leads to a vicious cycle of recurrent intestinal infestations and a high positive prevalence of parasites. Regular deworming programmes need to be adopted, at school level especially in the 3rd primary to 6th primary (8 -11 years old) level to keep the surge of intestinal parasites and their subsequent morbidities under a constant check.

Refrences

1. WHO. Intestinal protozoan and helminthic infections: report of a WHO scientific group. WHO Tech Rep Ser. 1981;666.

2. Richard L, Walker DH, Weller PR. In Tropical infectious diseases Principles Pathogens and Practice. 1st edition. Philadelphia: Churchill Living Stone; 1999.p.1–13

3. Centers for disease control: Intestinal Surveillance: United States 1976, MMWR 27:167,1978.

4. Tedla S. Intestinal helminthiasis in man in Ethiopia. Helminthologia. 1986;23:43–48. Crompton DWT, Savioli L. Intestinal parasitic infections and urbanization. Bulletin of the World Health Organization. 1993;71:1–7.

5. Singh DS, Hotchandani RK, Kumar S, Seecatt JS, Srivastava PK, Udupa KN. Prevalence and pattern of intestinal parasitism, A rural community of Varanasi. Indian Jour Prev Soc Md. 1984;15(1–2):1–8.

6. Croll NA, Anderson RM, Gyorkos TW, Ghadirian E. The population biology and control of Ascaris lumbricoides in a rural community in Iran. Trans R Soc Trop Med Hyg. 1982;76:187–97.

7. Schad GA, Nawalinski TA, Kochar V. Human ecology and the distribution and abundance of hookworm populations. In: Croll NA, Gross J, editors. Human ecology and infectious disease. New York: Academic Press; 1983. p.187–223.

8. Akogun OB. Some social aspects of helminthiasis among the people of Gumau District, Bauchi State, Nigeria. J Trop Med Hyg. 1989;92:193–6.

9. Chandiwana SK, Bradley M, Chombo M. Hookworm and round worm infections in farm-worker communities in the large-scale agricultural sector in Zimbabwe. J Trop Med Hyg. 1989;92:338–44.

10. Bradley M, Chandiwana SK. Age-dependency in predisposition to hookworm infection in the Burma valley area of Zimbabwe. Trans R Soc Trop Med Hyg. 1990;84:826–8.

11. De-Silva NR, de silva HJ, Jayapani VP. Intestinal parasitoses in the Kandy area, Sri Lanka. Southeast Asian J Trop Med Public Health. 1994;25(3):469–473.

12. Feachem RG, Bradley DT, Garelick H, MaraDD. Sanitation and disease: Health aspects of excreta and waste water management. World Bank studies in water supply and sanitation No. 3. New York: John Wiley and Sons. 1983.

13. Holland CV, Taren DL, Crompton DW, Nesheim MC, Sanjur D,Barbeau I, et al. Intestinal helminthiases in relation to the socioeconomic environment of Panamanian children. Soc Sci Med. 1988;26:209–13.

14. Kang G, Mathew MS, Rajan DP, Daniel JD, Mathan MM, Mathan VI, et al. Prevalence of intestinal parasites in rural Southern Indians. Trop Med Int Health. 1998;3:70–5.

lexapro pregnancy test