Monitoring and observing the trend distribution of intestinal parasitic infections in a certain community is a precondition for planning and evaluation of the existing intervention program. In line with this view, the present study attempted to assess five-year retrospective analysis of common intestinal parasites at Poly Health Center, Gondar, Northwest Ethiopia. The results of the study showed the occurrence of several intestinal parasites of public health importance among the community.
Although the present study used only wet mount technique that might have less sensitivity to diagnose light intestinal parasitic infections, the overall prevalence of intestinal parasite was 41.3% which was higher than other studies conducted in different part of Ethiopia; Bale-Robe (6.23%), Mojo Health Center (9.3%), Wonago Health center (16.6%) [21, 22, 23] and other countries’ report [24-35]. These differences in prevalence could be due to the use of different diagnostic methods and socio-demographic differences of the study subjects or it might be due to a reflection of the local endemicity and geographic condition of the study area.
Entameaba histolytica/dispar (40.7%) was the most prevalent intestinal parasite but it was lower than the previous study in Wonago Health center (53.8%) in Ethiopia [23]. However, the prevalence in the present study was higher than that of the studies done in Bale- Robe (26.3%) [21] and other countries, Palestine (16.3%) [24], Palajunoj Valley of Guatemala (16.1%) [25], Osmangazi University Medical Faculty in Turkey (31%) [29] and Kenitra in Morocco (23.7%) [35]. The prevalence of this study was also significantly higher than the studies conducted in Mojo Health Center (4.0%) in Ethiopia [21], Uludag University Medical School Hospital (5.4%), Istambul (0.05%), Tokat public Laboratory (0.8%), Dukuz Eylul University Medical Faculty Hospital (0.3%), Sivas municipality (3.7%) in Turkey, Riyadh Region (0.14%) in Saudi Arabia and Tehran (1.1%) in Iran [25-28, 30-32]. These differences might be due to the difference in diagnostic methods as discussed earlier. In addition, might be due to the difference in getting safe drinking water.
In the present study, G. lambilia (27.5%) was the second most prevalent intestinal parasite and A. lumbricoides (16.2%) as the leading helminthic parasite followed by H. nana, Hookworm, E. vermicularis, S. mansoni, with the prevalence of 4.1%, 3.3%, 2.4%, 2.4%, respectively and the least prevalence Taenia species (0.7%) which was differ from the studies done in Ethiopia [21, 22, 23] and others countries [24, 25-32, 35]. In addition to the possible factors like difference in diagnostic approach and the sources of safe drinking water discussed earlier, the differences in the proportions of these parasites in different studies might be also due to the difference in socio‐economic level, sanitary/hygienic status, occupation, and cultural activities and nutritional factors of the study populations.
The result of our study revealed that a slight fluctuating overall trend of intestinal parasitic infection was observed in the study area. A decreasing number of infections occurred in 2010 compared with reported in 2009. However, there was a gradual increment of a number of cases from 2011 to 2013 with higher intestinal parasite infection being reported in 2013. Similar studies in Ethiopia [22], Palestine [24], Turkey [26] and Saudi Arabia [31] reported a fluctuating trend of overall intestinal parasite infection. However, our study finding differed from the study conducted in Ethiopia [21] and Turkey [25] which was increasing and Turkey [29], Italy [33] and Morocco [34] which was decreasing trend parasite infection. The possible reason might be due to the difference prevention control strategy of different locality in a country and between countries, geographical differences, and the living condition of the study subjects. In the present study area, there is no prevention and control strategy except treating patients suspected and diagnosed for intestinal parasitic infections.
Out of the total data review in the last five years in the health center, males and females were equally affected for intestinal parasites infection except for Hookworm and S. mansoni. Males were more affected than females by Hookworm and S. mansoni. This study is consistent with the study done in Uludag University Medical School Hospital and Istanbul in Turkey [25, 26]. But in other studies in Mojo Health Center and Monago Health Center in Ethiopia [22, 23], Tokat Public laboratory, Osmangazi University Medical Faculty in Turkey [27, 29], females were more affected. The differences in the proportion of parasitic infection between males and females might be due to the difference in their daily activities. In the study area, males are mostly involved in outdoor activities like farming and swimming. These activities might expose more males to the soil-transmitted parasitic infection and intestinal flukes.
Regarding the age groups, 20 –29 years were highly affected groups, with a prevalence rate of (26.5%), followed by < 9-year-olds (24.9%). Entamoeba histolytica/dispar (28.4%), Hookworm (30.1%), and S. stercularis (32.0%) were higher in the earlier age groups. But the G. lamblia (30.3%), H. nana (46.1%), E. vermicularis (30.8%) and T. trichuria (34.0%) were higher in the later age groups. The 10–19 age groups were also affected by A. lumbricoide, S. mansoni, and Taenia species. The higher overall distribution of E. histolytica/dispar, Hookworm and S. stercularis in adolescence groups in the present study was in agreement with other studies in Ethiopia [21, 22] and other countries [25, 26, 28, 34]. But it differed from other studies done in the Wonago health center in Ethiopia and Catholic University Hospital in Italy [23, 33]. This may be probably due to the difference in hygienic status. The highest rate of infection was in the childhood, adolescent and oldest group. These indicate that these groups of persons are highly active and they are less likely to keep their hygiene. They might have close contact with pollutants with helminths infested soil or water bodies to play.