A tale of two communities: intestinal polyparasitism among Orang Asli and Malay communities in rural Terengganu, Malaysia

Intestinal parasitic infections and risk analysis among urban refugees in the Klang Valley, Malaysia

BACKGROUND

Global studies show intestinal parasitic infections (IPIs) have been introduced and spread with refugee inflows from low to high socio-economic countries. However, there is relatively limited information on the prevalence of infections among the community.

METHODS

A 2-year cross-sectional study was conducted to determine the prevalence and associated risk factors for infections among urban refugees in the Klang Valley, Malaysia. A total of 418 faecal samples were collected and examined by microscopy.

RESULTS

Faecal screening revealed moderate levels (32.3%) of infections in the community. Three nematode (Ascaris lumbricoides, Trichuris trichiura and hookworm) and three protozoan species (Entamoeba, Giardia and Cryptosporidium) were recorded, with the highest prevalence being A. lumbricoides (20.6%) followed by T. trichiura (10.3%), while other infections were <5%. Statistical analysis found that young males with less education were more likely to be infected with helminths. Additionally, living near waste disposal sites, the presence of stray animals, eating with bare hands, bare footedness, poor handwashing practices and no anthelmintic treatment constituted significant risk factors for helminth infections. Protozoan infections were linked to drinking tap water or from water dispensers and poor handwashing practices.

CONCLUSIONS

These findings emphasize the importance of health education in addition to introduction of biannual anthelmintic treatment to promote community health and well-being.

Systematic Review and Meta-Analysis: Epidemiology of Human Blastocystis spp. Infection in Malaysia

Blastocystis spp. is a unicellular enteric protozoan parasite in humans with a controversial role in disease etiology. It is common in developing countries among immunocompromised patients and people who have close contact with animals. In this study, we have systematically reviewed previous studies on the distribution and genotypes of human Blastocystis infection in Peninsular Malaysia. Studies examining the prevalence of Blastocystis in diverse demographics, including rural, urban, comorbid conditions, and high-risk populations, were taken into consideration. The infection has been reported in nine states; the total percentage of infection was 17.8% (1671/9397), with the most cases in Pahang (27.3%) and the least in Johor (3.4%). Molecular studies revealed the presence of six subtypes: ST1, ST2, ST3, ST4, ST5, and ST6. ST3 was reported as the predominant subtype in all the states, with a prevalence of 54.7% (338/618). The findings provide greater clarity on the epidemiology of Blastocystis in Malaysia, which will help in policy making towards planning and strategizing control measures against the parasite.

High prevalence of malnutrition and vitamin A deficiency among schoolchildren of rural areas in Malaysia using a multi-school assessment approach

Childhood malnutrition is known as a public health concern globally. The present study aims to assess the anthropometry and blood biochemical status of rural primary schoolchildren in Malaysia. A total of 776 children (7-11 years old) from ten rural primary schools from five states were included in this study. Nutritional outcomes were assessed based on sex, age group and school categories among the children (median age: 9 years (P25:8, P75:10)). The overall prevalence of malnutrition was 53·4 %. Vitamin A deficiency (VAD) was recorded at 20·6 and 39·8 % based on retinol and retinol-binding protein (RBP) levels, respectively. Anaemia, iron deficiency (ID), iron-deficiency anaemia (IDA) and elevated inflammation were found at 14·9, 17·9, 9·1 and 11·5 %, respectively. Malnutrition, VAD, anaemia, ID, IDA and elevated inflammation were more prevalent among Orang Asli (OA) schoolchildren compared with Non-Orang Asli schoolchildren. Higher occurrences of VAD and anaemia were also found among children aged <10 years. Retinol, RBP, α-carotene, ferritin and haemoglobin levels were lower among undernourished children. Besides, overweight/obese children exhibited a higher level of high-sensitivity C-reactive protein. Multivariate analysis demonstrated that OA school children (adjusted OR (AOR): 6·1; 95 % CI 4·1, 9·0) and IDA (AOR: 3·6; 95 % CI 1·9, 6·6) were associated with stunting among this population. The present study revealed that malnutrition, micronutrient deficiencies and anaemia are prevalent among rural primary schoolchildren in Malaysia, especially those from OA schools and younger age children (<10 years). Hence, more appropriate and targeted measures are needed to improve the nutritional status of these children.

Efficacy of triple dose albendazole treatment for soil-transmitted helminth infections

In Malaysia, soil-transmitted helminth (STH) infections still persist among indigenous communities. In the past, local studies have focused mostly on epidemiologic aspects of STH infections with a scarcity of information on the efficacy of deworming treatment. The present study consisted of 2 phases: a cross-sectional phase on current epidemiological status and risk factors of STH infections and a longitudinal study over 6 weeks on triple dose albendazole efficacy against STH infections. A total of 253 participants were recruited at baseline and a pre-tested questionnaire was administered to obtain information on socio-demographics, environmental and behavioural risk factors. Stool samples were evaluated using a modified Kato-Katz technique. Cure rate (CR) and egg reduction rate (ERR) were assessed at 3 weeks following a 3-day course of 400mg albendazole treatment and infection status were observed again at 6 weeks. Baseline positivity of trichuriasis, ascariasis and hookworm infections were 56.1%, 11.9% and 20.2%, respectively. Multivariate analysis showed age below 18 years old (P = 0.004), without latrine in house (P = 0.042) and indiscriminate defecation (P = 0.032) were associated with STH infections. In the longitudinal study (N = 89), CR for trichuriasis was 64.6%, while CR of 100% was observed for both ascariasis and hookworm. ERR was above 90% for all three STH species. A rapid increased of Trichuris trichiura egg output was observed at 6 weeks. In conclusion, STH infections are highly prevalent among indigenous communities. Children and teenagers, poor sanitation and hygiene behaviour were determinants for STH infections. Triple dose albendazole is found to be efficacious against Ascaris lumbricoides and hookworm infections but has moderate curative effect with high ERR against T. trichiura. Although triple dose albendazole regimen has logistic challenges and may not be a routine option, consideration of this treatment regime may still be necessary in selective communities to reduce high intensity of T. trichiura infection.

Assessing the prevalence and risk factors associated with Entamoeba complex infection among the Orang Asli school children in Perak, Malaysia through molecular approach

This study performed a cross-sectional investigation on the prevalence of Entamoeba complex infection comprising Entamoeba histolytica, Entamoeba dispar, and Entamoeba moshkovskii and their associated risk factors among the Orang Asli school children in three districts in Perak, Malaysia. Stool samples collected from 544 school children aged between 7 and 12 years old were examined through the nested multiplex PCR assay. The univariate and multivariate regression analyses were then carried out to determine the risk factor associated with Entamoeba complex infection. The overall prevalence of Entamoeba complex infections (E. histolytica, E. dispar and E. moshkovskii) was 21.3% (116/544). Most positive school children were infected with E. moshkovskii (10.7%; 58/544), followed by E. dispar (9.0%; 49/544) and E. histolytica (5.0%; 27/544). Not washing their hands after using the toilet was identified as the only significant risk factor for E. histolytica. The significant risk factors associated with E. moshkovskii infection included children within the age of 10-12 years old, with high BMI, living with working and non-educated mothers, no toilet in the house, not washing their hands after using the toilet, and fever. On the other hand, drinking water from the river, well, and rain was associated with a decreased risk of E. dispar infection. In conclusion, this study showed a high prevalence of Entamoeba spp. infections among the Orang Asli school children in Perak, Malaysia. Addressing the identified risk factors coupled with a holistic approach in breaking the transmission of Entamoeba complex can help improve their quality of life.

A Review of Human-Elephant Ecological Relations in the Malay Peninsula: Adaptations for Coexistence

Understanding the relationship between humans and elephants is of particular interest for reducing conflict and encouraging coexistence. This paper reviews the ecological relationship between humans and Asian elephants (Elephas maximus) in the rainforests of the Malay Peninsula, examining the extent of differentiation of spatio-temporal and trophic niches. We highlight the strategies that people and elephants use to partition an overlapping fundamental niche. When elephants are present, forest-dwelling people often build above-the-ground shelters; and when people are present, elephants avoid open areas during the day. People are able to access several foods that are out of reach of elephants or inedible; for example, people use water to leach poisons from tubers of wild yams, use blowpipes to kill arboreal game, and climb trees to access honey. We discuss how the transition to agriculture affected the human–elephant relationship by increasing the potential for competition. We conclude that the traditional foraging cultures of the Malay Peninsula are compatible with wildlife conservation.

Current state of infection and prevalence of giardiasis in Malaysia: a review of 20 years of research

Background

Giardiasis is a neglected parasitic zoonotic disease caused by Giardia duodenalis that is often overlooked despite the damage inflicted upon humans and domestic/wild animals. Lack of surveillance studies, low sensitivity of diagnostic tools, and resistance to giardiasis treatment add to the challenge in managing giardiasis, leaving a gap that continues to render giardiasis a silent threat to public health worldwide. This situation is not much different in Malaysia, where giardiasis remains a public health problem, especially in the indigenous communities. Realizing the existence of gaps in the literature and information on giardiasis in Malaysia, this review aims to revisit and update the situation of giardiasis in Malaysia based on articles published in 20 years from 2000 to 2020, providing estimates on the incidence of giardiasis in humans, animals, and the environment, which may inform efforts to prevent and control the impact of giardiasis in the country.

Methodology

We searched PubMed, Science Direct, and Scopus using MeSH terms and text keywords "Giardia duodenalis OR Giardia intestinalis OR Giardia lamblia OR intestinal protozoa AND Malaysia". Information was collected from all giardiasis reports published between 2000 and 2020.

Results

Giardiasis in Malaysia is more prevalent among the poorest segments of the population, namely the indigenous communities and people living in densely populated areas such as slums and prisons, due to low standard of personal hygiene, unsafe water resources, and improper sanitation. While the prevalence data is hugely dependent on microscopic fecal examination in epidemiological studies of giardiasis, current studies mostly focused on species identification and genotype distribution by multilocus genotyping. Thus far, the outbreak of giardiasis has not been reported in the country, but the disease was found to be significantly associated with stunting, wasting, and malnutrition among children of the indigenous communities. Surveillance studies also discovered the simultaneous presence of Giardia in the animal-environments, including wild animals, ruminants, and treated and untreated water. The data collected here will be a useful addition to the literature body on giardiasis in Malaysia, which can be exploited in efforts to prevent and control the impact of giardiasis in the country.

Conclusions

The last 10 years have shown that the overall mean rate of giardiasis in Malaysia is quite encouraging at 13.7%. While this figure appears to be declining, there has been a slight increase in the prevalence of underweight, stunting, and wasting among rural children in 2019. The fact that giardiasis is linked to long-term childhood developmental problems, indicates that addressing and providing better disease control against giardiasis should be a priority in supporting the national agenda to achieve Malaysia Global Nutrition Targets by 2025.

Perceptions and prevention practices on malaria among the indigenous Orang Asli community in Kelantan, Peninsular Malaysia

BACKGROUND

Malaysia is on track towards malaria elimination. However, several cases of malaria still occur in the country. Contributing factors and communal aspects have noteworthy effects on any malaria elimination activities. Thus, assessing the community's knowledge, attitudes and practices (KAP) towards malaria is essential. This study was performed to evaluate KAP regarding malaria among the indigenous people (i.e. Orang Asli) in Peninsular Malaysia.

METHODS

A household-based cross-sectional study was conducted in five remote villages (clusters) of Orang Asli located in the State of Kelantan, a central region of the country. Community members aged six years and above were interviewed. Demographic, socio-economic and KAP data on malaria were collected using a structured questionnaire and analysed using descriptive statistics.

RESULTS

Overall, 536 individuals from 208 households were interviewed. Household indoor residual spraying (IRS) coverage and bed net ownership were 100% and 89.2%, respectively. A majority of respondents used mosquito bed nets every night (95.1%), but only 50.2% were aware that bed nets were used to prevent malaria. Nevertheless, almost all of the respondents (97.9%) were aware that malaria is transmitted by mosquitoes. Regarding practice for managing malaria, the most common practice adopted by the respondents was seeking treatment at the health facilities (70.9%), followed by self-purchase of medication from a local shop (12.7%), seeking treatment from a traditional healer (10.5%) and self-healing (5.9%). Concerning potential zoonotic malaria, about half of the respondents (47.2%) reported seeing monkeys from their houses and 20.1% reported entering nearby forests within the last 6 months.

CONCLUSION

This study found that most populations living in the villages have an acceptable level of knowledge and awareness about malaria. However, positive attitudes and practices concerning managing malaria require marked improvement.

The Neglected Cestode Infection: Epidemiology of Hymenolepis Nana Infection Among Children in Rural Yemen

Hymenolepis nana is the most common cestode reported in humans worldwide. It is prevalent among children in the tropics and subtropics, particularly in rural poor communities where sanitation is inadequate or lacking. This cross-sectional study aims to determine the prevalence and significant risk factors of H. nana infection among children in rural Yemen. Faecal samples were collected from 498 children and screened for intestinal parasites by using wet mount, formalin-ether concentration and Kato–Katz techniques. A pretested questionnaire was used to collect demographic, socioeconomic, housing condition, and personal hygiene information. Overall, 77.5 % (386/498) of the children were found to be infected by at least one intestinal parasite species. The overall prevalence of H. nana was 17.5 % (87/498). Multivariate analysis confirmed that an age of < 6 years (adjusted odds ratio [AOR] = 4.28; 95 % (confidence interval [CI] = 2.04, 8.98), presence of other family members infected with H. nana (AOR = 2.48; 95 % CI = 1.45, 4.24), living in the highlands (AOR = 2.87; 95 % CI = 1.56, 5.26), living in a house without improved toilet facilities (AOR = 2.19; 95 % CI = 1.23, 3.88), not washing vegetables before consumption (AOR = 2.11; 95 % CI = 1.06, 4.19), and not washing hands after defecation (AOR = 1.88; 95 % CI = 1.08, 3.27) were the key factors significantly associated with H. nana infection among the studied children. In conclusion, H. nana is prevalent among children in rural Yemen, particularly among preschool-aged children. Thus, an integrated and effective programme to control intestinal parasitic infections should include preschool-aged children. Such a programme should focus on providing health education on hygienic practices, providing adequate sanitation and improved sources of drinking water, and screening and treating other infected family members.

Human intestinal parasitic infection: a narrative review on global prevalence and epidemiological insights on preventive, therapeutic and diagnostic strategies for future perspectives

INTRODUCTION

Intestinal parasitic infection (IPI) is a global health concern among socioeconomically deprived communities in many developing countries. Many preventative strategies have been deployed to control IPI, however, there is a lack in standards on the techniques used to diagnose and monitor the prevalence of IPI.

AREAS COVERED

The present article will review the diseases associated with IPI and discuss the current IPI control strategies such as the water, sanitation, and hygiene (WASH) interventions, community-led total sanitation (CLTS) approach, and regular anthelminthic treatments. For the first time, this review will also evaluate all currently practised diagnostic techniques for the detection of intestinal parasites and provide insights on future IPI control strategies.

EXPERT OPINION

Advanced and improved diagnostic methods such as qPCR coupled with a high-resolution melting curve, aptamers, biosensors, and detection of extracellular vesicles can be used for detection of IPI. Vaccination against intestinal parasites can be made available to increase antibodies to interfere with the blood-feeding process by the parasites, which subsequently reduces the reproductive rates of the parasites. These methods collectively can serve as future management strategies for intestinal parasitic infections.

The burden and epidemiology of polyparasitism among rural communities in Kano State, Nigeria

BACKGROUND

Parasitic infections constitute a major public health problem worldwide, particularly among underprivileged communities in developing countries including Nigeria. The present study aimed to determine the epidemiology of polyparasitism (multiple parasitic infections) among rural communities in Kano State, North Central Nigeria.

METHODS

A total of 551 individuals were screened for the presence of intestinal, urogenital and blood parasites by using different diagnostic techniques. Demographic, socioeconomic, household and behavioural characteristics were collected using a pre-tested questionnaire.

RESULTS

Overall, 84.0% (463/551) of the participants were found to be infected with at least one parasite species, with 51.2% (282/551) of them having polyparasitism. The most prevalent parasites were Plasmodium falciparum (60.6%) followed by Blastocystis sp. (29.2%) and hookworm (15.4%). No significant association was found between malaria and helminth infections (p>0.05). Univariate and multivariate analyses showed that the presence of other family members who had intestinal polyparasitism (adjusted odds ratio [AOR]=4.12; 95% CI=2.72, 6.24), walking barefoot outside (AOR=1.70; 95% CI=1.09, 2.63) and being male (AOR=1.74; 95% CI=1.14, 2.66) were the significant risk factors of intestinal polyparasitism among the population studied.

CONCLUSION

Polyparasitism is highly prevalent among rural communities in Kano State. Therefore, effective, sustainable and integrated control measures should be identified and implemented to significantly reduce the burden and consequences of these infections in rural Nigeria.

Amoebic toxic megacolon with poly-helminthic coinfection: Case presentation and review of intestinal polyparasitic infections

INTRODUCTION

Intestinal parasitic infections are a health burden to developing countries, but can also become more prevalent worldwide, even in developed countries, with the advent of globalization. While most of these infections are benign, some may be associated with acute infections with high morbidity and mortality rates.

CASE PRESENTATION

A 36 years old patient presented with toxic megacolon with poly-helminthic infections, likely a result of raw food ingestion. She subsequently required multiple surgeries with a total colectectomy and small bowel resection, and ended up with an end-ileostomy.

DISCUSSION

Intestinal polyparasitism has been reported in undeveloped countries, but it appears that such a trend can be found in developed countries as well. Clinicians, especially those practicing in countries with large expatriate or immigrant worker populations, should be aware of this trend and adjust treatment protocols accordingly.

CONCLUSION

Even in countries whereby intestinal parasitic infections are not common, clinicians should have a heightened awareness of the possibility for such infections to be present, especially in returning travellers, expatriate or immigrant populations.

A holistic approach is needed to control the perpetual burden of soil-transmitted helminth infections among indigenous schoolchildren in Malaysia

A cross-sectional survey was conducted among 1,142 Orang Ali schoolchildren in six states of Peninsular Malaysia to investigate the current prevalence and risk factors of STH infections. Faecal samples were examined using direct smear, formalin-ether sedimentation, Kato-Katz, and Harada-Mori methods. A pre-tested questionnaire was used to collect information on the demographic, socioeconomic, personal hygiene, and health status of the participants. Overall, 70.1% (95% CI = 67.4, 72.7) of the participants were infected with at least one of the STH species. The prevalence of Ascaris lumbricoides, Trichuris trichiura, and hookworm infections was 63.1%, 61.8% and 11.5%, respectively. Moderate-to-heavy STH infections accounted for 61.3% of the total infections. Univariate and logistic regression analyses revealed different sets of risk factors, with age (> 10 years) being the significant risk factor of all three STH species. Moreover, other species-specific risk factors were identified including being a member of the Senoi tribe, family size (≥ 7 members), school size (150-250 pupils), maternal unemployment, unimproved source of drinking water, lacking improved toilet in the house, inadequate WASH facilities at school, not washing hands before eating, and not washing fruits before eating; presence of domestic animals, and not wearing shoes when outside. The high prevalence of STH infections found in the study population exceeds the WHO policy intervention threshold (20% prevalence). Thus, an innovative holistic approach should be adopted to control STH infections among these children as part of the efforts to improve the quality of life of the entire Orang Asli population. .

Prevalence and risk factors of Strongyloides stercoralis infection among Orang Asli schoolchildren: new insights into the epidemiology, transmission and diagnosis of strongyloidiasis in Malaysia

This cross-sectional study aimed to determine the prevalence and risk factors of S. stercoralis infection among 1142 Orang Asli primary schoolchildren in six different states of Peninsular Malaysia. Fecal samples were examined using direct smear, formalin-ether sedimentation (FES), agar plate culture (APC) and PCR techniques. Overall, 15.8% of the children were found to be infected with S. stercoralis. The prevalence was 0.2, 1.3, 15.2 and 13.7% by direct smear, FES, APC and PCR, respectively. Multivariate analysis showed that an age of >10 years, being male, belonging to a Proto-Malay tribe, belonging to the Senoi tribe, indiscriminate defecation, using an unimproved water source for drinking water and not wearing shoes when outside were the significant risk factors of infection among these children. In conclusion, we provide new evidence on the occurrence of S. stercoralis in Malaysia to show that there is a relatively high prevalence of infection among Orang Asli schoolchildren. Therefore, the use of specific methods for detecting S. stercoralis should be considered when screening these children for intestinal parasites. Moreover, prevention and control measures specific to S. stercoralis should be integrated into the intestinal parasitic infections control programme in Malaysia.

Sociodemographic, nutritional, and environmental factors are associated with cognitive performance among Orang Asli children in Malaysia

Children aged 2 to 6 years are in a crucial period of growth development, during which it is important for them to attain specific cognition related to concentration and attention so that they can perform well in school later in life. Various factors influence children’s cognition during this crucial period. However, to date, only a limited number of studies have examined the cognitive performance of underprivileged children living in poverty, particularly indigenous children (also known as Orang Asli children in Malaysia). Therefore, this cross-sectional study aimed to determine the associations between sociodemographic factors, nutritional factors (body composition and hemoglobin), and environmental factors (home environment and parasitic infections) with cognitive performance among Orang Asli children in Negeri Sembilan, Malaysia. The participants were 269 children (51% boys, 49% girls) aged 2 to 6 years (M = 4.0, SD = 1.2 years) and their mothers, from 14 Orang Asli villages. Face-to-face interviews were conducted with the mothers, and the children’s cognitive performance, operationalized as working memory index (WMI), processing speed index (PSI), and cognitive proficiency index (CPI), was assessed using the Wechsler Preschool and Primary Scale of Intelligence, Fourth Edition (WPPSI-IV). The children’s weight and height were measured, and their blood and stool samples were collected to assess hemoglobin level and parasitic infections, respectively. Multiple linear regression analysis showed that the father’s years of education (β = 0.262–0.342, p < 0.05), availability of learning materials at home (β = 0.263–0.425, p < 0.05), and responsiveness of the parent to the child (β = 0.192–0.331, p < 0.05) were consistently associated with all three cognitive indices (WMI, PSI, and CPI). A holistic approach involving parents, communities, and government agencies should be established to improve the cognitive performance of these underprivileged children.

Analysis of knowledge and attitudes related to parasitic infections among inhabitants of Ahvaz County, Khuzestan Province, Iran

Parasitic diseases are among the major health problems of various societies, especially people in developing countries, causing high economic and mortality burdens. Many researchers have reported that awareness and knowledge of a disease are effective in preventing and controlling the disease. The aim of the present study was to assess the knowledge and attitudes on parasitic diseases of the population in Ahvaz County, southwestern Iran. This community-based cross-sectional study was carried out in 2017 on 3500 subjects above 15 years old of Ahvaz County. First, participants were provided the necessary information regarding the study, and then data were collected using a constructed questionnaire. Of the 3500 participants, 1732 (49.5%) were female and 1768 (50.5%) were male, 348 (9.9%) said that they had been infected with a parasitic disease at least once in their lifetime. Almost half of the participants (42.8%) knew malaria was a parasitic disease and 50.2%, 48.9%, and 41.5% were aware of the possible transmission of parasitic diseases through uncooked meat, dirty hands, and close contact with animals. Regarding clinical symptoms, 73.2% and 32.6% of the respondents knew diarrhea and abdominal pain respectively were clinical symptoms of intestinal parasitic diseases. However, only 31.3% were aware of the close contact with cats and the risk of human toxoplasmosis and possible abortion in pregnant women. The findings reveal that the attitude of most participants toward treatment was positive (93.9%), but only 47.5% of believed that disinfecting fruits and vegetables could prevent intestinal parasitic infections.

Prevalence, intensity and associated risk factors of soil transmitted helminth infections: A comparison between Negritos (indigenous) in inland jungle and those in resettlement at town peripheries

BACKGROUND

Formerly known as the Malaysian hunter gatherers, the Negrito Orang Asli (OA) were heavily dependent on the forest for sustenance and early studies indicated high prevalence of intestinal parasitism. Initiation of a redevelopment program in the 1970s aimed to demarginalize the OA was expected to reduce soil transmitted helminth (STH) infections. Gradually, the OA were relocated to new resettlement areas at the peripheries. The aim of this study was to compare STH infections between Negritos who are still living in the inland jungle with those living in resettlements.

METHODOLOGY/PRINCIPAL FINDINGS

A total of 416 Negrito participants were grouped into two categories of communities based on location; Inland Jungle Villages (IJV); and Resettlement Plan Scheme (RPS). Iodine wet mount, formalin-ether sedimentation, modified Trichrome and modified Ziehl-Neelsen staining and Kato-Katz methods were performed on stool samples. A questionnaire was used to collect information regarding demographic, socioeconomic, environmental and hygiene behaviors. Prevalence of STH was significantly higher in IJV (91.3%) versus RPS (83.1%) (P = 0.02). However, the percentage of individuals with severe intensity of Trichuris trichiura infections was significantly higher in the RPS (17.2%) compared to IJV (6.5%) (P = 0.01). Severe Ascaris lumbricoides infection was observed at 20.0% amongst RPS Negritos and 15.0% amongst IJV (P = 0.41). Whilst for hookworm infection, both prevalence and individuals with moderate to severe infections were higher in the IJV (26.2%, 41.0%) versus RPS (18.7%, 24.0%) (P values = 0.08, 0.09), accordingly. The prevalence other intestinal parasitic infections (e.g. Entamoeba sp., Blastocystis and flukes) was also higher in IJV versus RPS. Apart from poor hygienic behaviors as significant risk factors in both communities, low socio-economic status was highly associated with STH infections in RPS (P<0.001) but not significantly associated in IJV.

CONCLUSIONS

The findings showed that ex situ development plan by RPS has not profoundly contributed to the STH reduction among the OA. Conversely, burden rate of T. trichiura infections increased due to their extreme poverty and poor hygienic behaviors. Here, we are suggesting biannual mass albendazole intervention (triple dose regimens in RPS, but a single dose in IJV) and community empowerment to both communities. For a long-term and better uptake, these strategies must be done together with the community input and participation, respecting their traditional customs and accompanied by recruitment of more OA people in the health-care taskforce.

Prevalence and risk factors for intestinal parasitic infections in pregnant women residing in three districts of Bogotá, Colombia

BACKGROUND

Intestinal parasitic infections (IPI) lead to significant morbidity and mortality in pediatric and adult populations worldwide. Intestinal parasitism during pregnancy is of interest as it may affect the health of pregnant women and their offspring. This study determined the prevalence of IPI in pregnant women living in substandard conditions in three urban districts of Bogotá, Colombia. Associations between prevalence and sociodemographic factors, housing, and living conditions were also evaluated.

METHODS

In a cross-sectional and community-based study, pregnant women were recruited from three districts of Bogotá. A total of 550 participants answered a questionnaire; 331 of these also provided stool samples, with 233 providing one and 98 providing two stool samples. Questionnaire responses were associated with the presence of intestinal parasites, which was determined using a standard combined microscopy technique including direct wet mount and formol-ether concentration. Results were verified by supplementary examination of 48 stool samples by quantitative polymerase chain reaction (qPCR).

RESULTS

Among pregnant women who lived in selected poor residential areas in Bogotá, the overall prevalence of intestinal parasitism was 41% with 9% polyparasitism. Pathogenic parasites were present in 1.2% of the 331 participants including Giardia lamblia and Ascaris lumbricoides. Higher prevalence was found for parasites with debated pathogenicity, including Blastocystis hominis (25%), Endolimax nana (15%), Entamoeba coli (8%), and Iodamoeba butschlii (2%). Entamoeba histolytica/dispar complex was also detected (1.5%). When comparing a subset of stool samples using the combined microscopy technique and qPCR, the latter detected a higher 58.3% overall IPI prevalence. Higher prevalence of infections by any intestinal parasite was found in participants who had never been dewormed (p = 0.01). Higher but not statistically significant associations were found between any parasite and women living with a partner, and intestinal polyparasitism and being from a minority group and not having a water sink.

CONCLUSIONS

This first study of the prevalence of intestinal parasitism in Bogotá focused on pregnant women living in poverty, found a high prevalence of intestinal parasites of debated pathogenicity, and confirmed a low prevalence of pathogenic intestinal parasites. These results highlight the need for educational interventions to disrupt transmission routes for prevalent parasites.

Soil-Transmitted Helminths in Tropical Australia and Asia

Soil-transmitted helminths (STH) infect 2 billion people worldwide including significant numbers in South-East Asia (SEA). In Australia, STH are of less concern; however, indigenous communities are endemic for STH, including Strongyloides stercoralis, as well as for serious clinical infections due to other helminths such as Toxocara spp. The zoonotic hookworm Ancylostoma ceylanicum is also present in Australia and SEA, and may contribute to human infections particularly among pet owners. High human immigration rates to Australia from SEA, which is highly endemic for STH Strongyloides and Toxocara, has resulted in a high prevalence of these helminthic infections in immigrant communities, particularly since such individuals are not screened for worm infections upon entry. In this review, we consider the current state of STH infections in Australia and SEA.

Segregated settlements present an increased risk for the parasite infections spread in Northeastern Slovakia

The occurrence of parasitic infections among the children, dogs and its association with soil contamination in two villages with different hygiene level standards were analysed. Infections were present in both examined localities, but in the village with higher living standard, a better personal and communal hygiene level and better dogs care a lower occurrence of parasitic germs in soil was detected. High prevalence of protozoa and helminths was observed not only within canine population but also in children throughout the year in the village with lower hygiene and socio-economic standard. We have identified up to 12 taxa of parasites in 127 collected dogs’ excrements and mean prevalence was 71.65 %. The most frequent were eggs of family Ancylostomatidae and Ascaris spp., followed by Toxocara canis, Toxascaris leonina, Giardia duodenalis cysts, Isospora spp. oocysts, eggs of Capillaria aerophila, Trichuris vulpis, Taenia type eggs, Dipylidium caninum, oocysts of Sarcocystis spp. and larvae of Angiostrongylus vasorum. The soil samples collected near dwellings were highly contaminated. Two thirds of samples contained eggs for the most part of family Ancylostomatidae as well as genera Ascaris and Toxocara. Among the kids population helminth ova were present in 53.17 % of stool samples, where the eggs of Ascaris lumbricoides, Trichuris trichiura, Enterobius vermicularis, Hymenolepis diminuta and cysts of G. duodenalis were the most frequent. In contrast, parasitic diseases were not seen in children population living in the locality with common hygiene standard.

First molecular epidemiology of Entamoeba histolytica, E. dispar and E. moshkovskii infections in Yemen: different species-specific associated risk factors

OBJECTIVES

To investigate the molecular epidemiology of Entamoeba histolytica, E. dispar and E. moshkovskii infections among rural communities in Yemen.

METHODS

In a community-based study, faecal samples were collected from 605 participants and examined by wet mount, formalin-ether sedimentation, trichrome staining and nested multiplex PCR techniques. Demographic, socio-economic and environmental information was collected using a pre-tested questionnaire.

RESULTS

Overall, 324 (53.6%) of the samples were positive for Entamoeba cysts and/or trophozoites by microscopic examination. Molecular analysis revealed that 20.2%, 15.7% and 18.2% of the samples were positive for E. histolytica, E. dispar and E. moshkovskii, respectively. Multivariate analysis showed different sets of species-specific risk factors among these communities. Educational level was identified as the significant risk factor for E. histolytica; age and gender were the significant risk factors for E. moshkovskii; and sources of drinking water and consumption of unwashed vegetables were the significant risk factors for E. dispar. Moreover, living in coastal/foothill areas and presence of other infected family members were risk factors for both E. histolytica and E. moshkovskii infections.

CONCLUSION

The study reveals that Entamoeba spp. infection is highly prevalent among rural communities in Yemen, with E. histolytica, E. dispar and E. moshkovskii differentiated for the first time. Identifying and treating infected family members, providing health education pertinent to good personal and food hygiene practices and providing clean drinking water should be considered in developing a strategy to control intestinal parasitic infections in these communities, particularly in the coastal/foothill areas of the country.

Perspective on the Genetic Response to Antiparasitics: A Review Article

BACKGROUND

Drugs' pharmacokinetics and pharmacodynamics can be affected by diverse genetic variations, within which simple nucleotide polymorphisms (SNPs) are the most common. Genetic variability is one of the factors that could explain questions like why a given drug does not have the desired effect or why do adverse drug reactions arise.

METHODS

In this retrospective observational study, literature search limits were set within PubMed database as well as the epidemiological bulletins published by the Mexican Ministry of Health, from Jan 1st 2001 to Mar 31st 2017 (16 years).

RESULTS

Metabolism of antiparasitic drugs and their interindividual responses are mainly modified by variations in cytochrome P450 enzymes. These enzymes show high frequencies of polymorphic variability thus affecting the expression of CYP2C, CYP2A, CYP2A6, CYP2D6, CYP2E6 and CYP2A6 isoforms. Research in this field opens the door to new personalized treatment approaches in medicine.

CONCLUSION

Clinical and pharmacological utility yield by applying pharmacogenetics to antiparasitic treatments is not intended as a mean to improve the prescription process, but to select or exclude patients that could present adverse drug reactions as well as to evaluate genetic alterations which result in a diversity of responses, ultimately seeking to provide a more effective and safe treatment; therefore choosing a proper dose for the appropriate patient and the optimal treatment duration. Furthermore, pharmacogenetics assists in the development of vaccines. In other words, the aim of this discipline is to find therapeutic targets allowing personalized treatments.