Methods and Results of Survey
Subject area and Methods
The subject of parasitological surveys were inhabitants of the Kella・Sergent Village in Bouar Area of Savanna Zone in the north of 470 km from Bangui city and M'Banza Village in M'Baiki Area of Jungle Zone in the west of 130 km from Bangui as usual. At Kella・Sergent Village, a total of 127 inhabitants were examined, and 111 cases who brought their stools in same day, have been done the stool examination using with the methods of cellophane thick smear technique. Among 35 helminths eggs positive cases, treated with Pyrantel pamoate for hookworm positives, Mebendazole for trichiuriasis and Praziquantel for both of schistosomiasis mansoni and Trematodes eggs (look like Heterophyes sp. eggs) positive cases. At M'Banza Villege, a total of 60 inhabitants were examined and 57 out of them received the stool examination with the direct thick smear method, and 24 cases were hookworm egg positive, one each case were positive for Trichuris trichura and Schistosoma mansoni eggs. All cases treated with Pyrantel pamoate also give Mebendazol for trichuriasis and Praziquantel for shistosomiasis after get the results in the same day.
All stools of Kella・Sergent Village specimens after direct examination were fixed with formalin at the laboratory of Bouar Hospital. These fixed specimens were brought back to Japan and examined with MGL centrifugation technique.
The detection of Schistosoma haematobium on 120 specimens at Kella・Sergent Village and 57 specimens at M'Banza Village have been done by urine examination, however all cases were negative. These urine specimens were tried new technique for the detection of IgG4 using with Brugia pahangi antigen under the permission of chief of each villages.
Hundred twenty seven cases of Kella・Sergent Village and 59 cases of M'Banza were made the blood smear for the examinations both of lymphatic filariasis and malaria, and were examined after Giemsa staining in Japan.
However, the skin snips for detection of Onchocerca volvulus have not done both village in this time because there is not found in past several years.
The applicants for this surveys are exist in a great number and many inhabitants are waiting for our consultation. However, examination time is very limit for our staying terms because of the internal trouble in this country as Japanese Embassy was closed, unfortunately. Moreover direct flight from Paris to Bangui is only once per week at the moment, and one day should be cut of our staying terms for the reason of early check in the baggage for countermeasure against high-jack problems in one day before when our departure. Then the survey projects were decided only two villages of Kella・Sergent and M'Banza which were same places done the surveys from about 20 years over. In Kella・Sergent village, methods of examination have been done the stool with both of thick smear and MGL methods, and urine, blood examinations as usual, however. in M'Banza village have been done only direct thick smear method in stool examination but urine and blood examinations were tried the same methods with Kella・Sergent village done.
At Kella・Sergent Village, health note check and blood smear preparations were done under the tree in the village because the weather was fine without rainfall, and direct thick smear stool examinations, and the stool treatment of formalin fixation for MGL and making the blood smear specimens to brought back in Japan have been done in Bouar Hospital. At M'Banza Village, direct thick smear stool examinations were done under the tree with microscope, and same time the formalin treatment of blood smear fixation have been done by the reasons of no electricity in this village. Urine specimens of both village were collect in the nunc tubes for the bring back to Japan.
All the fix materials were bought back and examined to Japan and Dr. Yaya who was company with us, done the reception and help as interpreter of traditional language, and also clinical consultation for several patients.
a) Stool examinations
The stool specimens of 111 inhabitants of Kella・Sergent Village and 57 stools of M'Banza Village were examine using with the methods of direct cellophane thick smear technique in locals of each villages. And 111 specimens of of Kella・Sergent Village were fixed with formalin in the nunc tubes.
These fixed specimens were brought back to Japan and examined with MGL methods (formalin-ether centrifugation technique) using iodine staining for the detections of helminthes eggs and protozoan cysts. All out of 57 stool specimens in M'Banza Village inhabitants were not enough time for the preparation for fixation in this year, then these specimens were tested with the methods of direct cellophane thick smear technique only for the detections of helminthes eggs.
b) Blood Examination
Each blood from 186 persons in total of 127 at Kella・Sergent Village and 57 at M'Banza Village were drawn, and made the both of thick and thin blood smear for the examinations of lymphatic filariasis and malaria. These specimens were dried at locals and brought back to Japan. The thick smears were hemolysis with distilled water, and the both of thin smears and hemolytic thick smears were stained with Giemsa after methyl alcohol fixation in the laboratory in Japan. Finally, the detection of microfilariae and Plasmodium have been done by microscope.
c) Urine Examination
For the detection of Schistosoma haematobium and the new technique for detection of IgG antibody using with Brugia pahangi antigen, 127 inhabitants at Kella・Sergent Village and 59 specimens have been done by the urine sedimentation technique, and all specimens of urine were collect in the nunc tubes for the bring back to Japan and examined in the laboratory of Department of Parasitology, Aich Medical University School of Medicine
All helminths eggs positive cases of both villages of Kella・Sergent and M'Banza which were recognized with the methods of direct cellophane thick smear were given the anti-helminths drugs at locals in the same day. Namely, hookworm positives treated with Pyrantel pamoate bring from Japan, Mebendazole for trichiuriasis and Praziquantel for both of schistosomiasis mansoni and Trematodes egg positive cases.
And other helminths positives were treated with each effective drugs according to the results of examinations in last year. Diethylcarbamazine for filariasis, Metronidazole for amoebiasis, Chroloquine and Mefloquine for malaria were used. And moreover, several anti-helminths drugs such as Pyrantel pamoate, Thiabendazole, Mebendazole, Praziquantel, Chroloquine. Mefloquine and Metronidazole were donated to Doctors and Infirmers of Bouar Hospital and to Infirmers of M'Banza Dispensary, and demand to give to the patients according to the individual results data of inhabitants of the subject villages.
a) Results of stool examinations
Stool examinations for helminth eggs were performed with both methods of cellophane thick smear technique (modified Kato-Katz method) and formalin-ether centrifugation technique (MGL method) in Kella・Sergent Village. With the MGL technique, using iodine staining protozoan cysts were also examined after the specimens brought back to Japan. Out of 111 stools at Kella・Sergent Village, 59 (53.2%) were found for helminth eggs as shown in Table 1 and 2 [43.4% in 2002 of last year, 25.7% in before the last year of 2001 and 60.8% in 2000], 47(42.7%) of hookworm [38.5% in 2002, 21.3% in 2001, 45.7% in 2000], 15 (13.5%) of Schistosoma mansoni [13.7% in 2002, 5.1% in 2001, 27.1% in 2000], and 7 (6.3%) of Trichuris trichiura [0.5% in 2002, 0.7% in 2001, 1.5% in 2000], 1 (0.9%) of Trema-tode egg (like to Heterophyes sp. egg) [0.5% in 2002, 0.7% in 2001, 0.5% in 2000 with Hymenolepis nana] and 2 (1.8%) of Capillaria sp. eggs were positives.
On the other hand, 25 (43.9%) out of 57 stools at M'Banza Village were detected for helminthes eggs in spite of direct thick smear method. [55.6% in 2002, 18.4% in 2001, 50.8% in 2000 with both techniques of direct thick smear method and MGL technique], and 24 (42.1% hookworm [54.2% in 2002, 16.30% in 2001, 50.8% in 2000 with both methods], 1 case (1.8%) Schistosoma mansoni [1.4% in 2002, 1.6% in 2001. O in 2000 with both methods] and also 1 case (1.8%) of Trichuris trichiura were positives, however not recognized Ascaris lumbricoides even positives in last two year's examinations.
Results of the examination for protozoan cysts at Kella・Sergent Village by MGL are as shown in Table 3. Out of 111 stools, the protozoan cysts were found in 75 (67.6%) [59.3% in 2002, 64.1% in 2001, 63.3% in 2000], Entamoeba histolytica in 23 (20.7%) [14.8% in 2002, 17.6% in 2001, 11.1% in 2000], Entamoeba coli in 57 (51.4%) [42.9% in 2002,43.5% in 2001, 47.2% in 2000], Endolimax nana in 34 (30.6%) [35.7% in 2002, 50.4% in 2001, 39.2% in 2000], Iodamoeba butshlii in 42 (37.8%) [17.6% in 2002, 30.5% in 2001, 20.1% in 2000] and Giardia lambria in 11 (9.9%) [11.5% in 2002, 14.5% in 2001, 9.5% in 2000], respectively. The prevalence rates of protozoan cysts in Kella・Sergent Village were high, as mentioned above.
b) Results of urine examinations
Results of the examination for urinal schistosomiasis by the detection of Schistosoma haematobium eggs from the urine specimens on 120 inhabitants at Kella・Sergent Village and 57 inhabitants at M'Banza Village, no egg positive cases were found in this time as shown in Table 4.
c) Results of blood examinations for lymphatic filariasis
Results of the examination for microfilaria by blood thick and thin smear technique with Giemsa staining specimens are shown in Table 5 . Out of 127 cases at Kella・Sergent Village, the microfilaria were detected in 8 cases (15.0%) only [15.0% in 2002, 7.3% in 2001, 11.3% in 2000]. Among 8 positives, 6 (87.5%) were positive for Mansonella perstans and 2 (25.0%) were positive for Loa loa. At M'Banza Villege, 34 cases (57.6%) [38.1% in 2002, 42.3% in 2001, 24.7% in 2000] out of 59 inhabitants were positive, and among 34 positives, 31 (91.2%) were Mansonella perstans cases and 12 (35.3%) were Loa loa cases. It was very clear that the positive ratio of filariasis in M'Banza Village of Jungle Zone is higher than in Kella・Sergent Village of Savanna Zone, and the Mansonella perstans infection is more important than the Loa loa infection in both areas from the results of mentioned above.
d) Results of blood examinations for malaria
Results of the examination for Malaria by the detection of Plasmodium from the same blood smear of microfilariae research specimens are shown in Table 6. Out of 127 cases at Kella・Sergent Village, the total Plasmodium were found in 68 cases (53.5%) [64.0% in 2002, 58.3% in 2001, 57.6% in 2000], and 29 cases (49.2%) out of 59 inhabitants at M'Banza Village [70.0% in 2002, 64.6% in 2001, 80.8% in 2000] were detected. Positive rate of both villages situated in Savanna (Kella・Sergent Villege) and Jungle (M'Banza Villege) was very high. Among the malaria positive cases, 26 (37.7%) out of 68 positives were found Plasmodium falciparum, and 58 cases (85.3%) were Plasmodium malariae at Kella・Sergent Village, and 12 (41.4%) out of 29 positives were Plasmodium farciparum, and 21 (72.4%) were recognized Plasmodium malariae at M'Banza Village. Plasmodium ovale was not found in this year. No Plasmodium vivax were found in Central African Republique from our past surveys. There was no significant difference in the prevalence rates of Plasmodium infection among both villages. And among the malaria patients. about 24% among the positive cases in Kella・Sergent Village were mixed infection with both species of Plasmodium falciparum and Plasmodium malariae, and about 14% in M'Banza Village were mixed infection of both species.
e) Results of mixed infections
Results of mixed infections of parasites on the cases who were received all examinations in Kella・Sergent Village are shown in Table 7. Positive rate in this year was 91.5% (97 out of 106 cases). There were little high positive rate compared with the results of recent several years in the same village, such as 93.4% in 2002, 88.1% in 2001, 93.0% in 2000 and 89.5% in 1999, but not so much different significantly.
And the average number of species per person was 2.93 species in this time, and the past were 2.84 species in 2002, 2.81 species in 2001, 2.98 species in 2000 and 3.00 species in 1999. The average number of species of parasite infections on the Health Note holders who were received already our examinations and treatments in the past was 3.10 species, and the average number of species in the persons who were received in new cases is 2.84 species as shown in Table 8. The reason of number of species in the new cases was little smaller than the Health Note holder in this time, many new cases of inhabitants may come from urban area such as Bangui to this village as evacuation by the political trouble of civil war. From the above mentioned result, it suggest that these persons have been received the good medical care when they lived in urban areas.
f) Individual results of the examinations in each case
The individual results of parasitological examinations of Kella・Sergent Village and M'Banza Village are as shown in Table 9 and 10.
The new individuals numbers who were received parasitological and medical consultation by us were increased in each year . It seems to be that the increased reasons may succeed and spread to have the knowledge and interesting on the health problems by our activities such as health education to individuals, and the neighbor villagers even evacuation persons from urban areas were also visit to our consultation and increased every years gradually.
Total of the persons who were received all examinations of stools by both methods of cellophane thick smear technique and MGL method, blood smear for lymphatic filariasis and malaria, and urine examination for urinal schistosomiasis, were 106 in Kella・Sergent Village and 57 in M'Banza Villege (provided for the stool examinations were done the cellophane thick smear technique only. Then ptozoan cysts were not examined). Among them, 97 cases (91.5%) out of 106 were positive for any parasite in Kella・Sergent Village and 46 cases (80.7%) out of 57 in M'Banza Villege as shown in Table 7, 9 & 10. Namely 9 cases (8.5%) in Kella・Sergent Village were parasites free. This results were compared with the results of recent past several years. In Kella・Sergent Village, positive rate of 2002 were 93,4% (170 out of 182), 88.1% (111 out of 128) in 2001, 93.0% (185 out of 199) in 2000, 89.5% (162 out of 181) in 1999, and 94.5% in 1995, 100% in 1985 which were not described in this Table.
The average number of parasites species per person was 2.93 species in this time, and the past average numbers were 2.84 species in 2002, 2.81 species in 2001, 2.98 species in 2000 and 3.00 species in 1999. However, the average number of species of parasite infections cases on the Health Note holders who were received already our examinations with treatments in the past were gradually little decreased except in this year. In M'Banza Village, the average number of parasites species were not so decreased . The reasons of not decreases on both of positive rate and the numbers of species, there are seems to be the exist of vectors present by the situation in Jungle areas and many visitors visit in this village because very closed the capitol city.