Prevalence and Associated Risk Factors of Toxocara vitulorum Infections in Buffalo and Cattle Calves in Three Provinces of Central Cambodia

The prevalence and associated risk factors of Toxocara vitulorum infection in buffalo and cattle calves was studied in 3 provinces in central Cambodia. Fecal samples were collected from 517 calves between the age of 1-15 weeks and processed for nematode egg counts by a modified McMaster method. A total of 64 calves were found to excrete T. vitulorum eggs in their feces (12.4%; 95% exact CI: 9.7-15.5). The mean fecal egg count was 2,798 EPG (SD=16,351; range=0-224,400). A multivariable generalized linear mixed model showed higher odds of T. vitulorum infection for buffalo versus cattle, for animals aged 4-8 weeks versus younger and older ones, and for animals with strongyle infection. There was no association with fecal consistency. Farmers should be aware of the potential impact of T. vitulorum, and treat their calves at the age of 2-3 weeks with anthelmintics such as benzimidazoles or pyrantel.

Zoonotic Trematode Metacercariae in Fish from Phnom Penh and Pursat, Cambodia

A survey was performed to investigate the infection status of freshwater fish with zoonotic trematode metacercariae in Phnom Penh and Pursat Province, Cambodia. All collected fish with ice were transferred to our laboratory and examined using the artificial digestion method. In fish from Phnom Penh, 2 kinds of metacercariae (Opisthorchis viverrini and Haplorchis yokogawai) were detected. O. viverrini metacercariae were positive in 37 (50.0%) of 74 fish in 11 species (average no. metacercariae/fish, 18.6). H. yokogawai metacercariae were detected in 23 (57.5%) of 40 fish in 5 species (average no. metacercariae/fish, 21.0). In fish from Pursat Province, 5 kinds of metacercariae (O. viverrini, H. yokogawai, Haplorchis pumilio, Centrocestus formosanus, and Procerovum sp.) were detected; O. viverrini metacercariae (n=3) in 2 fish species (Henicorhynchus lineatus and Puntioplites falcifer), H. yokogawai metacercariae (n=51) in 1 species (P. falcifer), H. pumilio metacercariae (n=476) in 2 species (H. lineatus and Pristolepis fasciata), C. formosanus metacercariae (n=1) in 1 species (H. lineatus), and Procerovum sp. metacercariae (n=63) in 1 species (Anabas testudineus). From the above results, it has been confirmed that various freshwater fish play the role of a second intermediate host for zoonotic trematodes (O. viverrini, H. yokogawai, H. pumilio, C. formosanus, and Procerovum sp.) in Cambodia.

Prevalence of Intestinal Helminths among Inhabitants of Cambodia (2006-2011)

In order to investigate the status of intestinal helminthic infections in Cambodia, epidemiological surveys were carried out on a national scale, including 19 provinces. A total of 32,201 fecal samples were collected from schoolchildren and adults between 2006 and 2011 and examined once by the Kato-Katz thick smear technique. The overall egg positive rate of intestinal helminths was 26.2%. The prevalence of hookworms was the highest (9.6%), followed by that of Opisthorchis viverrini/minute intestinal flukes (Ov/MIF) (5.7%), Ascaris lumbricoides (4.6%), and Trichuris trichiura (4.1%). Other types of parasites detected were Enterobius vermicularis (1.1%), Taenia spp. (0.4%), and Hymenolepis spp. (0.2%). The northwestern regions such as the Siem Reap, Oddar Meanchey, and Banteay Meanchey Provinces showed higher prevalences (17.4-22.3%) of hookworms than the other localities. The southwestern areas, including Koh Kong and Preah Sihanouk Provinces showed higher prevalences of A. lumbricoides (17.5-19.2%) and T. trichiura (6.1-21.0%). Meanwhile, the central and southern areas, in particular, Takeo and Kampong Cham Provinces, showed high prevalences of Ov/MIF (23.8-24.0%). The results indicate that a considerably high prevalence of intestinal helminths has been revealed in Cambodia, and thus sustained national parasite control projects are necessary to reduce morbidity due to parasitic infections in Cambodia.

High Prevalence of Opisthorchis viverrini Infection in a Riparian Population in Takeo Province, Cambodia

Opisthorchis viverrini infection was found to be highly prevalent in 3 riverside villages (Ang Svay Chek A, B, and C) of the Prey Kabas District, Takeo Province. This area is located in the southern part of Cambodia, where the recovery of adult O. viverrini worms was recently reported. From May 2006 until May 2010, fecal examinations were performed on a total of 1,799 villagers using the Kato-Katz thick smear technique. In the 3 villages, the overall positive rate for helminth eggs ranged from 51.7 to 59.0% (av. 57.4%), and the percentage positive for O. viverrini was 46.4-50.6% (47.5%). Other helminths detected included hookworms (13.2%), echinostomes (2.9%), Trichuris trichiura (1.3%), Ascaris lumbricoides (0.6%), and Taenia spp. (0.06%). The prevalence of O. viverrini eggs appeared to reflect a lower infection in younger individuals (20 years). Men (50.4%) revealed a significantly higher (P=0.02) prevalence than women (44.3%). The Ang Svay Chek villages of the Prey Kabas District, Takeo Province, Cambodia have been confirmed to be a highly endemic area for human O. viverrini infection.

Echinostoma ilocanum Infection in Oddar Meanchey Province, Cambodia

Fecal examinations using the Kato Katz technique were performed on a total of 1,287 villagers (945 students and 342 general inhabitants) of Oddar Meanchey Province, Cambodia in May 2007 and November 2009. The overall intestinal helminth egg positive rate was 23.9%, and the most prevalent helminth species was hookworms (21.6%). Other helminth eggs detected included echinostomes (1.0%), Enterobius vermicularis (0.8%), small trematode eggs (0.7%), which may include Opisthorchis viverrini and Haplorchis spp., and Hymenolepis nana (0.4%). In order to recover adult echinostomes, we treated 2 patients with 10-15 mg/kg praziquantel and purged. Total 14 adult echinostomes, 1 and 13 worms from each patient, were collected. The echinostomes characteristically had 49-51 collar spines and 2 round or slightly lobated testes. They were identified as Echinostoma ilocanum (Garrison, 1908) Odhner, 1911. So far as literature are concerned, this is the first record on the discovery of human E. ilocanum infection in Cambodia.

Changes in STI services following a community based STI-intervention project in Cambodia.

The aim of this study was to assess changes in sexually transmitted infections (STI) related care following a STI project with a particular focus on registered brothel-based (direct) female sex workers (DFSWs) in four border provinces of Cambodia. A survey of health care facilities providing STI care was undertaken and the results compared with a baseline survey done two years previously. The main components of the project were: renovation of the STI clinics, STI training, formation of mobile teams, provision of STI drugs, and the introduction of basic laboratory tests at STI clinics. Interviews were held with health care providers and STI patients and a manual check was made of the STI register and special forms for DFSWs. Clinical management of STI cases was assessed for DFSWs, women with vaginal discharge and men with urethral discharge. Advice given to clients about condom use, partner notification and STI education was assessed and availability of STI drugs was reviewed. STI clinic attendance by DFSWs each month increased from 72% (296/412) to 93% (459/496). The proportion of DFSWs diagnosed with presumed STIs decreased from 86.5% (256/296) to 25.5% (117/459) and cervicitis from 32.8% (135/412) to 12.6% (58/459). The percentage of men attending STI clinics decreased from 26.9% (251/933) to 9.4% (102/1,080). The proportion of presumed STI cases/all cases attending health centers decreased from 7.0% (934/13,177) to 4.3% (739/17,224). The introduction of laboratory tests coincided with a marked reduction in DFSWs diagnosed with cervicitis. Further validation studies are required to determine whether this reduction was accompanied by a real decrease in gonorrhea and chlamydia.

Leptospirosis in Takeo Province, Kingdom of Cambodia, 2003.

BACKGROUND: In Cambodia, epidemiology and disease burden of leptospirosis were not addressed as they do not have an existing surveillance system and have limitations on their laboratory diagnosis. OBJECTIVE: Define the existence of leptospirosis and determine the antibodies to serovars of leptospires in Cambodia. MATERIAL AND METHOD: One hundred and twenty-one suspected cases of leptospirosis were enrolled in this cross-sectional study, between September 8 and November 30, 2003 from Takeo Provincial Hospital in Doun Keo District, Cambodia. RESULTS: Common clinical manifestations were fever (96%), headache (92%), and myalgia (87%). Common risk behaviors were throwing garbage on the ground (84%), pulling out sprouts (77%), fertilizing (49%), and plowing (47%). Microscopic agglutination test result confirmed four cases and polymerase chain reaction test result confirmed seven cases. Two cases each showed antibodies to serovars Javanica and Australis. An estimated annual incidence of leptospirosis in Takeo province was 7.65 per 100,000 populations. Further studies to define epidemiology and burden of disease are needed. CONCLUSION: Increasing awareness and knowledge on leptospirosis among people are necessary to decrease the impact of leptospirosis in Cambodia.

Opportunistic infections and HIV clinical disease stage among patients presenting for care in Phnom Penh, Cambodia.

This prospective, cross-sectional study sought to assess the spectrum of HIV-associated complications and disease stage among individuals presenting for first-time care in Phnom Penh, Cambodia between November 2001 and September 2002. One hundred patients participated in this study. All study participants presented with advanced stages of HIV disease. Seventy-four percent of the subjects had CD4 cell counts <50 cells/mm3. Tuberculosis was the most common AIDS-defining illness among participants, with a prevalence of 43%. A spectrum of other opportunistic infections, including cryptosporidiosis (13%), severe bacterial infections (12%), cryptococcosis (12%), and Pneumocystis jiroveci pneumonia (10%), was identified. These findings underscore the need for widespread HIV treatment and prevention in this setting. Increased screening for HIV and routine health maintenance for those infected are urgently needed in order to facilitate management of both opportunistic infections and the secondary prevention of HIV infection.

Intestinal parasites in school-aged children in villages bordering Tonle Sap Lake, Cambodia.

The objective of this study was to study Schistosoma mekongi and other intestinal parasitic infections, and intestinal symptoms and related complaints among school-age children and adolescents living around Tonle Sap Lake. Villages were selected where there were potential signs of schistosomiasis (hepatomegaly), and where subjects complained of intestinal symptoms. Stool samples were collected from 1,616 children and were examined by Kato-Katz, SAF concentration, and Baermann technique; short clinical examinations were also performed. No S. mekongi infection was detected, although a high level of intense human water contacts was reported. Helminth infection such as Ascaris lumbricoides (27.7%) and hookworms (29.7%) were common. Trichuris trichiura 4.4%), Hymenolepis nana (6.2%), Giardia lamblia (4.2%), and Entamoeba spp (14.4%) were also recorded. Strongyloides stercoralis was frequently diagnosed (20.2%). It was concluded that it is unlikely that S. mekongi is transmitted in Tonle Sap Lake. However, other intestinal parasitic infections are widespread. In particular, S. stercoralis should be considered an important etiologic agent in children and adolescents with abdominal complaints.

Effect of wealth inequality on chronic under-nutrition in Cambodian children.

The problems of food insecurity and under-nutrition remain particularly severe in countries recovering from recent wars or civil unrest, where improvements in economic conditions have tended to benefit the advantaged groups and resulted in widespread inequalities in health. Using information on 3235 children aged 0-59 month(s) included in the 2000 Cambodia Demographic and Health Survey, this study examined how economic inequality was associated with inequalities in chronic childhood under-nutrition. An under-nourished (stunted) child was defined as having his/her height-for-age more than two standard deviations below the reference median. Household wealth status was measured by an index based on household ownership of durable assets. Binary and multinomial logistic regressions were used for estimating the effects of household wealth status on moderate and severe stunting. The results indicated that children in the poorest 20% households were more than twice as likely to suffer from stunting as children in the richest 20% households (odds ratio [OR]=2.54; 95% confidence interval [CI] 1.91-3.39). Adjusting for child's age, sex, birth order, and duration of breastfeeding; age of mother at childbirth, body mass index, and education; and household access to safe drinking-water, hygienic toilet facility, residence, and geographic region made little difference to this effect (OR=2.05; 95% CI 1.28-3.28). The adjusted effect of wealth status was somewhat stronger on severe stunting (relative risk ratio [RRR]=2.26; 95% CI 1.22-4.18) than on moderate stunting (RRR=1.89; 95% CI 1.12-3.20). The study concludes that wealth inequality is strongly associated with chronic childhood under-nutrition and emphasizes that reducing poverty and making services more accessible to the poor will be key to improving the health and nutritional status of children in Cambodia.

Chronicle of malaria epidemics in Thailand, 1980-2000.

The occurrence of malaria epidemics in Thailand was reviewed from the malaria surveillance report of the National Malaria Control Program. The literature review revealed that the four epidemic periods recorded during 1980-2000 almost always occurred in the provinces and districts located along international borders. Malaria epidemics are caused by various factors such as: extensive population movement, multi-drug resistance development, low immune status of the population, lack of knowledge and appropriate personal protection against mosquito biting, and the re-emergence of malaria transmission in low malarious areas. Such factors can lead to changes in the parasite ratio and appearance of malaria epidemics throughout the country. Evidence related to the burden of malaria epidemics was also reviewed to identify causal factors that will be helpful in future research.

The first reported cases of disseminated histoplasmosis in Cambodia, complicated by multiple opportunistic infections.

Although disseminated histoplasmosis is recognized as a common opportunistic infection in HIV-infected persons living in endemic areas, it is not widely reported in Southeast Asia, and has not been reported in Cambodia. It remains unanswered whether this is secondary to a low disease prevalence, or whether the disease, which is associated with a nonspecific clinical presentation, is under diagnosed. In addition to a review of the literature regarding histoplasmosis in Southeast Asia, we provide a description of two HIV-1 infected patients with documented disseminated histoplasmosis complicating other opportunistic infections in Phnom Penh, Cambodia. These two cases highlight the need for both a high clinical suspicion, and reliable laboratory testing, in a setting where there is likely to be more than one infection complicating the patient's clinical course.

Postinjury malaria: experiences of doctors in Battambang Province, Cambodia.

Quantitative studies indicate that one-third of trauma victims in malaria endemic areas of Cambodia develop postinjury malaria. The main aim of this study was to assess the medical significance of the complication. All local doctors with trauma care surgical experience in the Battambang Province of Cambodia were interviewed regarding their experiences with postinjury malaria (n = 18). The qualitative data were processed according to the Editing Style Analysis method. In the study area, postinjury malaria has been a well-known complication to trauma doctors for years. Local doctors claim that the complication is more common in severe as compared to moderate trauma. The complication is reported to adversely affect the general condition of trauma patients, increasing the risk of wound infections, and delaying postoperative recovery. It was found that the informants draw exclusively on personal clinical experience regarding this clinical knowledge, asserting that postinjury malaria is not taught at local medical schools. The study indicated that post-injury malaria is a significant complication to trauma where falciparum malaria is endemic. The knowledge of postinjury malaria in the study area seemed to be non-institutional; the informants' assessments were exclusively based on their personal clinical experience.

Baseline assessment for addressing acute malnutrition by public-health staff in Cambodia.

The objective of this study was to formulate appropriate responses by the public-health sector to reduce acute malnutrition among children in Cambodia. A cross-sectional survey to identify wasting together with a simple wealth-ranking exercise was conducted. Thereafter, separate focus-group discussions were also conducted with mothers of malnourished and non-malnourished children, who belonged to the poorest strata, to identify coping mechanisms and to assess feeding and hygiene practices. There was no statistical correlation between wasting and socioseconomic status (df=3, p=0.06). Reported feeding practices were poor, including not giving of colostrum, too early introduction of weaning, low feeding frequency, and late introduction of nutritious foods. Healthcare-seeking behaviour appeared inadequate, and hand-washing with soap was not practised. Acute malnutrition was mainly related to these factors rather than to food insecurity. An education campaign in tandem with peer-counselling would be the most appropriate option.

Oral health status among 12-year-old children in primary schools participating in an oral health preventive school program in Phnom Penh City, Cambodia, 2002.

A cross-sectional survey was undertaken to assess dental caries status, knowledge, attitude and practice in oral health among 12-year-old primary schoolchildren participating in the Oral Health Preventive School Program (OHPSP) conducted since 1998 in Phnom Penh City, Cambodia. Schools were stratified into 3 groups by levels of cooperation (good, partial, and poor) with the OHPS program and samples of schools randomly selected from each group. A total sample size of 239 schoolchildren was randomly selected from the sampled schools. There were 79, 82, and 79 children from schools with good, partial, and poor cooperation, respectively. Dental caries status DMFT (Decayed Missing Filled teeth) and knowledge, attitude and practices in oral health were assessed from 21 January to 5 February 2002. Opinions of school directors toward the OHPS Program were evaluated by interview. The results showed the overall mean DMFT per person in schoolchildren in Phnom Penh City, Cambodia of 2.33 (95%CI=2.05-2.61) while mean DT(Decayed teeth) was 2.31 (95%CI=1.97-2.52) and mean MT (Missing teeth) and mean FT (Filled teeth) were 0.01 per person, which were quite small. Children from schools with good cooperation with the OHPSP had the lowest significant mean DMFT 1.62 (95%CI=1.25-1.98) compared to children from schools with partial and poor cooperation (Mean DMFT=2.67:95%CI=2.10-3.23, and 2.69:95%CI=2.19-3.19, respectively). There were no significant differences in levels of knowledge, attitude and practices in oral health among the 3 groups of schools, but the proportion of good practices was highest in good cooperation schools compared to the schools with partial and poor cooperation to the OHPSP (41.3%, 27.3%, and 31.3%, respectively). Among 35 school directors, the majority of them (97.1%) believed that the OHPS program can reduce the dental caries prevalence among schoolchildren. Only 20.0% agreed that parents of schoolchildren should pay money to the school for tooth brushes and tooth paste of their children for brushing after lunch at school. The remaining answers were, they were uncertain (37.1%) and disagree (42.9%) that the school should have to manage that donated money. Among them, 82.9% reported that the OHPS Program activities did not disturb their time at school; 65% of them agreed there should be volunteers to help the schools in implementing the activities of the program. The majority of school directors (97.1%) thought that oral health examinations for schoolchildren were necessary. The results of the study suggested a need for continuous monitoring and strengthening of activities and cooperation of the Oral Health Preventive School Program among primary schools in Phnom Penh City to reduce the prevalence of dental caries among primary schoolchildren in Phnom Penh City, Cambodia.

Status of intestinal parasite infections among children in Bat Dambang, Cambodia

A survey was conducted to determine the extent of intestinal parasite infection in Bat Dambang, Cambodia in March 2004. A total of 623 fecal specimens was collected from kindergarten and schoolchildren and examined using the formalin-ether sedimentation technique. The overall infection rate of intestinal parasites was 25.7% (boys, 26.2%; girls, 25.1%), and the infection rates of intestinal helminthes by species were as follows: Echinostoma sp. 4.8%, hookworm 3.4%, Hymenolepis nana 1.3%, and Rhabditis sp. 1.3%. The infection rates of intestinal protozoa were; Entamoeba coli 4.8%, Giardia lamblia 2.9%, Iodamoeba butschlii 1.4%, Entamoeba polecki 1.1%, and Entamoeba histolytica 0.8%. There were no egg positive cases of Ascaris lumbricoides or Trichuris trichiura. All children infected were treated with albendazole, praziquantel, or metronidazole according to parasite species. The results showed that intestinal parasites are highly endemic in Bat Dambang, Cambodia.

Intestinal helminthic infections in schoolchildren in Cambodia.

During the period January to December 1998, the National Malaria Center (CNM) carried out a parasitological survey of schoolchildren in rural and semi-urban areas, to assess intestinal helminthic infections in schoolchildren in the central parts of Cambodia. In the rural areas, there were four schools in Stung Treng Province (all situated along the Mekong River), five schools in Kratie Province (around rubber plantations), six schools in Kampong Chhnang Province (along Tonle Sap Lake); and in the semi-urban areas, three schools in Beng Tumpon Commune and five schools in Chbar Ampeou Commune (Mean Chey District) were selected for study. By Kato-Katz technique, the prevalence of soil-transmitted helminthic infections in schoolchildren in both the rural and urban areas was high. The infection rate was between 10-40% for Ascaris, 2-17% for Trichuris and 5-65% for hookworm. Schistosomiasis and opisthorchiasis were found in the schoolchildren living along the Mekong River (Stung Treng Province); the infection rate of S. mekongi ranged from 12 to 43%. These infections in children were with hepatomegalies. An intervention in an urban area (Chraing Chamres) showed that after repeated treatment with mebendazole 500 mg single dose every 6 months, the prevalence of all parasites had dropped to about one third of the initial level.

Underweight schoolchildren in a rural school near the Thai-Cambodian border.

We report on the high prevalence of underweight children in a rural primary school near the Thai-Cambodian border. Ninety-five children were studied: anthropometric data were recorded and studied for their correlation with semester examination scores; 63.2% of the children (60 cases) were underweight; in addition, BMI appeared to be significantly correlated to the semester examination scores. Our findings also revealed problems of nutrition and sanitation among the schoolchildren. In conclusion, schoolchildren in rural areas should be considered a priority in the national health and nutrition promotion programs.

Mekong malaria. II. Update of malaria, multi-drug resistance and economic development in the Mekong region of Southeast Asia.

In an expansion of the first Mekong Malaria monograph published in 1999, this second monograph updates the malaria database in the countries comprising the Mekong region of Southeast Asia. The update adds another 3 years' information to cover cumulative data from the 6 Mekong countries (Cambodia, China/Yunnan, Lao PDR, Myanmar, Thailand, Viet Nam) for the six-year period 1999-2001. The objective is to generate a more comprehensive regional perspective in what is a global epicenter of drug resistant falciparum malaria, in order to improve malaria control on a regional basis in the context of social and economic change. The further application of geographical information systems (GIS) to the analysis has underscored the overall asymmetry of disease patterns in the region, with increased emphasis on population mobility in disease spread. Of great importance is the continuing expansion of resistance of P. falciparum to antimalarial drugs in common use and the increasing employment of differing drug combinations as a result. The variation in drug policy among the 6 countries still represents a major obstacle to the institution of region-wide restrictions on drug misuse. An important step forward has been the establishment of 36 sentinel sites throughout the 6 countries, with the objective of standardizing the drug monitoring process; while not all sentinel sites are fully operational yet, the initial implementation has already given encouraging results in relation to disease monitoring. Some decreases in malaria mortality have been recorded. The disease patterns delineated by GIS are particularly instructive when focused on inter-country distribution, which is where more local collaborative effort can be made to rationalize resource utilization and policy development. Placing disease data in the context of socio-economic trends within and between countries serves to further identify the needs and the potential for placing emphasis on resource rationalization on a regional basis. Despite the difficulties, the 6-year time frame represented in this monograph gives confidence that the now well established collaboration is becoming a major factor in improving malaria control on a regional basis and hopefully redressing to a substantial degree the key problem of spread of drug resistance regionally and eventually globally.

The first reported cases of canine schistosomiasis mekongi in Cambodia.

We have been conducting surveys of schistosomiasis mekongi along the Mekong river in Cambodia since 1997. We attempted to detect canine schistosome infection during the survey in 2000 because dogs were reported to be natural reservoirs of the Mekong schistosome in Lao PDR. A total of 28 canine fecal samples were collected in Kbal Chuor village, Kratie Province and examined for schistosome eggs. One specimen had schistosome eggs (positive rate = 3.6%; egg density = 100/gram stool), which showed characteristics of Schistosoma mekongi. During the 2001 survey, one out of 310 canine stool samples was positive for schistosome eggs (positive rate = 0.32%; egg density = 3,456/gram stool). These are the first confirmed cases of canine schistosomiasis mekongi in Cambodia, which suggests that dogs are animal reservoirs of S. mekongi in the survey area. We further tried to detect S. mekongi in cows, water buffalos, pigs,horses, and field rats in five villages in Kratie Province; no schistosome egg was found in the stools of these animals.