Ascaris lumbricoides among children in rural communities in the Northern Area,Pakistan: prevalence,intensity, and associated socio-cultural and behavioral risk factors

The prevalence and intensity of Ascaris lumbricoides in 492 children from five rural villages in the Northern Area of Pakistan was examined. The overall prevalence of A. lumbricoides was 91% (95%CI 88.6-93.6) with geometric mean (GM) egg count intensities of 3985 eggs per g (epg). The most intense A. lumbricoides infections were found in children aged 5-8 years. We also investigated selected socio-cultural and behavioral variables for A. lumbricoides infections that might be relevant for the design of appropriate prevention and control programs. Univariate analysis associated A. lumbricoides intensity with age (P=0.004), location of household (P<0.01), defecation practices (P=0.02), soil eating habit (P<0.01), hand washing after defecation (P<0.01), and living with children under 5 years old (P=0.02). Multivariate analysis identified the children's age 5-8 (P<0.01), location of household in Surngo, Askole, and Stakchun where the pilot health care model activities were not done (P<0.01), and living with children under 5 years old (P=0.03) as variables statistically associated with the intensity of A. lumbricoides. The results indicated that there were certain clear risk factors in A. lumbricoides transmission, and that its intensity was influenced by age-related behavioral and environmental factors that contribute to exposure.     

Physiographic and entomologic risk factors of malaria in Assam, India

Fever surveys were conducted in several districts of the Indian state of Assam to ascertain the prevalence of malaria in relation to vector abundance, entomologic inoculation rates (EIRs), and geographic location of human settlements. Anopheles minimus were incriminated, but their relative abundance and biting rates varied among districts, and no significant correlation was observed between these two indicators (r = 0.43, P = 0.34). Plasmodium falciparum was the predominant parasite species except in two districts where P. vivax was the majority parasite. The EIRs per person/night were 0.46-0.71 in P. falciparum-predominant areas and 0.12 in the district where P. vivax predominated. The correlation of percentage of fever cases positive for malaria infection in each district with the corresponding EIR was not significant (r = 0.6, P = 0.21). Malaria cases were detected in all months of the year but peaked during May-June, which corresponded to the months of heavy rainfall. These were also the months with highest incidence of infection with P. falciparum. Malaria cases were observed in all age groups of both sexes, and there was clustering of cases in villages near the vector-breeding habitat (perennial seepage streams), and foothill villages. However, malaria incidences were consistently lower in villages within 5 km of the nearest health care facility, which were in town areas. The data presented are indicative of low-to-moderate levels of malaria transmission by An. minimus, and would be of value for developing future intervention strategies.     

Trichuris and hookworm infections associated with anaemia during pregnancy

Objective To assess the following associations between the second and third trimesters of pregnancy: (i) the intensity of soil‐transmitted helminth (STH) infection and haemoglobin/anaemia, (ii) the effect of mebendazole treatment on the occurrence of STH infection, and (iii) the effect of mebendazole treatment on haemoglobin/anaemia. Methods Data originated from a trial of 1042 pregnant women recruited in their second trimester and followed to delivery. Baseline assessments included socio‐demographic/health information from questionnaires, haemoglobin/anaemia from HemoCue ascertainment of fingerprick blood, and the presence and intensity of STH (Ascaris lumbricoides, hookworms and Trichuris trichiura) infections from Kato–Katz examination. All women were given iron supplements; half were randomly allocated to receive single dose 500 mg mebendazole, and half, placebo. Haemoglobin/anaemia and STH infection status were determined again in the third trimester of pregnancy. Results Complete information was available from 935 (89.7%) women. Mebendazole significantly reduced the prevalence and intensity of all three STH infections. Higher intensities of hookworm and Trichuris infections in the second trimester were associated with a higher risk of anaemia in the third trimester. Overall, women with moderate/heavy Trichuris infection were found to be at a higher risk of anaemia; the highest risk was observed among those with moderate/heavy hookworm co‐infection (adjusted OR = 2.77; 95% CI: 1.26, 6.11). Mebendazole treatment did not reduce the risk of anaemia. Conclusion Higher intensities of both Trichuris and hookworm infections are associated with anaemia in pregnancy. The importance of Trichuris infections during pregnancy requires renewed attention.     

Prevalence, intensity and risk factors for soil-transmitted helminth infection in a South Indian fishing village

A study of the prevalence, intensity and risk factors for soil-transmitted helminth infection was undertaken among school children aged 5-9 years attending a primary school in the fishing village in Peda Jalaripet, Visakhapatnam, South India. One hundred and eighty nine (92.6%) of 204 children were infected with one or more soil transmitted helminth parasites. The predominant parasite was Ascaris lumbricoides (prevalence of 91%), followed by Trichuris trichiura (72%) and hookworm (54%). Study of age-specific prevalence and intensity of infection revealed that the prevalence and intensity of A. lumbricoides infection was higher among younger children than older children. While aggregation of parasite infection was observed, hookworm infection was more highly aggregated than either A. lumbricoides or T. trichiura. Multivariate analysis identified parental occupation, child's age and mother's education as the potential risk factors contributing to the high intensity of A. lumbricoides infection. Children from fishing families with low levels of education of the mother had the highest intensity of A. lumbricoides infection. As the outcome of chemotherapy programs to control soil transmitted helminth infection is dependant on the dynamics of their transmission, there is a need for further studies to better define the role of specific factors that determine their prevalence, intensity and aggregation in different epidemiological settings.     

我国西南彝族农村地区HIV与血吸虫 蛔虫及鞭虫感染现状调查

目的 目的 了解我国西南彝族农村地区HIV、 血吸虫、 蛔虫及鞭虫感染状况, 调查是否存在混合感染。 方法 方法 在我 国西南部某山区随机选取一个彝族乡开展横断面调查, 检测村民HIV、 血吸虫、 蛔虫及鞭虫感染情况; 并对村民进行问卷 调查, 了解HIV及寄生虫感染的危险因素。 结果 结果 我国西南彝族农村地区居民HIV、 血吸虫、 蛔虫和鞭虫感染率分别为 2.33%、 2.05%、 13.47%和30.59%, 鞭虫与蛔虫共同感染检出率为7.08%, HIV与蛔虫和鞭虫共同感染检出率均为0.23%。 男性以及吸毒是HIV感染的危险因素 ［OR = 3.26, 95% CI：（0.97, 10.95）; OR = 72.86, 95% CI： （18.51, 286.76）］; 厕所与蛔 虫和鞭虫感染间均存在负相关关系 ［OR = 0.51, 95% CI：（0.27, 0.98）; OR = 0.48, 95% CI：（0.28, 0.80）］。与居住在村4的 居民相比, 村1村民感染蛔虫风险较高 ［OR = 3.14, 95% CI：（1.35, 7.27）］; 与居住在村4的居民相比, 居住在村2和村3的 村民鞭虫感染风险较高 ［OR = 3.73,95% CI：（1.92, 7.26）; OR = 4.53, 95% CI：（2.12, 9.68）］。此外, 11～20岁年龄组村民 鞭虫感染风险高于>50岁村民 ［OR = 3.72, 95% CI：（1.59, 8.67）］; 蛔虫与鞭虫感染间存在相关关系 ［OR = 3.11, 95% CI： （1.63, 5.93）］, 未发现与血吸虫感染相关的因素。 结论 结论 我国西南彝族农村居民HIV及寄生虫感染率尤其是鞭虫感染 率较高; 应进一步探索HIV与寄生虫感染, 尤其是与血吸虫感染间的关系。     

Giardia duodenalis infection among rural communities in Yemen: A community-based assessment of the prevalence and associated risk factors

Objective: To investigate the prevalence and risk factors of Giardia infection among rural communities among rural communities in Yemen.Methods: In this cross-sectional study, a total of 605 stool samples were collected and screened for the presence of Giardia duodenalis(G.duodenalis) cysts and/or trophozoites by using three different diagnostic methods: direct smear, formalin-ether sedimentation,and trichrome staining.A pre-tested questionnaire was used to collect information on the demographic, socioeconomic, behavioural and environmental characteristics of the participants.Results: Overall, 28.1%(170/605) of the participants were infected by G.duodenalis.The prevalence was significantly higher among male participants compared to female(P = 0.034); however, it was not significant among different age groups(P 0.05).Univariate and multivariate analyses identified four variables as the significant key risk factors of Giardia infection among the sampled communities.These are, in addition to being of the male gender, using unsafe water sources for drinking water, not washing hands after defecation, presence of other family members infected with Giardia, and close contact with domestic animals.Conclusions: The study reveals that Giardia infection is still prevalent among rural communities in Yemen.The provision of clean and safe drinking water, proper sanitation,and health education regarding personal hygiene practices, particularly handwashing, as well as identifying and treating infected family members is imperative and these interventions should be considered in a strategy to control intestinal parasites among these communities in order to curtail the transmission and morbidity caused by G.duodenalis.     

Community-based epidemiology of hepatitis B virus infection in West Bengal, India: prevalence of hepatitis B e antigen-negative infection and associated viral variants

BACKGROUND AND AIMS: There is a paucity of population-based epidemiological information regarding hepatitis B virus (HBV) infection in India. The present study was planned to outline the magnitude and pattern of HBV infection, hepatitis B e antigen (HBeAg)-negative infection and the associated viral mutants in India. METHODS: A community-based epidemiological study of HBV infection was carried out in West Bengal, India. Serological markers of infection and potential risk factors for HBV transmission were determined. Among the infected individuals, HBV-DNA, genotypes and mutations in the precore (PC) stop codon and basal core promoter (BCP) regions were determined by DNA sequencing and polymerase chain reaction (PCR) restriction fragment length polymorphism methods. RESULTS: Of the 7653 people included in the study, 227 (2.97%) tested positive for hepatitis B surface antigen (HBsAg), of whom 204 (90%) were HBeAg-negative and hepatitis B e antibody (anti-HBe)-positive, and 78% had normal alanine aminotransferase (ALT) levels. HBV-DNA could be detected by PCR in only 32% of people. G1896A PC stop codon mutants were present in 12% of people, BCP mutants in 18% and the remainder (70%) of the HBeAg-negative infections were associated with wild type sequences in these regions. CONCLUSIONS: This first general population-based epidemiological study of HBV infection from India suggests that HBV acquisition starts in early childhood and peaks in adulthood. Most infections in the community are e-negative and inactive. The point prevalence of PC stop codon and BCP mutants is low in this primarily inactive and asymptomatic HBV-infected population sample in eastern India.     

The epidemiology of human hookworm infections in the southern region of Mali

Two surveys of hookworm (Necator americanus) infections, conducted three years apart (December 1994 and January 1998) in a village in the Sikasso region of Mali, revealed that overall prevalence of infection was 68.7% and 53%, respectively. In both years there was a highly significant difference between the sexes in the prevalence and abundance of infection, with male subjects carrying heavier infections than females. Both prevalence and abundance of infection increased with age, although in 1998 there was a strong interaction between sex and age, arising from the declining egg counts among 16-20-year-old females and the continuing increase among males, reinforced by the subsequent reduction among the older males (> or = 61 years) and concomitant increase among females. After controlling for the effects of age, sex and their interaction, a highly significant positive relationship was detected between faecal egg counts of individuals who were examined in both 1994 and 1998 (n = 134), indicating predisposition to infection. This relationship remained significant in each of 4 age classes spanning 7-79 years. The members of some family compounds were shown to carry heavier infections than expected whilst others were less infected, suggesting compound-related clustering of hookworm infections. The use of footwear increased with age but there was no significant relationship between the extent of use of footwear and the abundance of hookworm infection. Eyesight deteriorated with age and impaired vision was particularly prominent among the older sectors of the community, a legacy from the time when onchocerciasis was widely prevalent in the region. Although men with partially damaged eyes carried lower infections than expected for their age, no overall significant relationship was found between quality of vision and hookworm infections. These results are discussed in relation to hookworm epidemiology in general and in Mali in particular.     

Population-based study to estimate prevalence and determine risk factors of gallbladder diseases in the rural Gangetic basin of North India

Background

A high prevalence of gallbladder diseases (GBD) in Northern India warranted a population survey into environmental risk factors.

Methods

In 60 villages of Uttar Pradesh and Bihar from 13 334 households, 22 861 persons aged >30 years were interviewed for symptoms of GBD, diet and environmental factors. Subsequently ultrasonography (US) was performed in 5100 and 1448 people with and without symptoms, respectively. Heavy metal and pesticide content in soil and water were estimated.

Results

US revealed a prevalence of GBD of 6.20%. GBD was more common in 5100 persons with symptoms (7.12%) compared with 1448 without (2.99%) (P < 0.05). Adjusted odds ratio (ORs) [95% confidence interval (CI)] revealed a significantly increased risk of GBD in females >50, 1.703 (CI 1.292–2.245); multiparity 1.862 (CI 1.306–2.655) and a genetic history 1.564 (CI 1.049–2.334). An increased risk noted in males with diabetes was 4.271 (CI 2.130–8.566), chickpea consumption 2.546 (CI 1.563–4.146) and drinking unsafe water 3.835 (CI 2.368–6.209). Prevalence of gallstones was 4.15%; more in females 5.59% than males 1.99% (P < 0.05). Cluster analysis identified a positive correlation of nickel, cadmium and chromium in water with a high prevalence of GBD in adjacent villages in Vaishali district, Bihar.

Conclusion

A high risk of GBD was observed in older, multiparous women and men with diabetes, intake of chickpeas, unsafe water and villages with heavy metal water pollution.     

鄱阳湖区人群土源性线虫感染与土壤污染状况调查

目的了解鄱阳湖区进贤县4个村土壤中土源性线虫卵污染情况及其与人群感染率的关系。方法在4个村131户农户的庭院、客厅、厕所、菜园4处采集土壤,土壤寄生虫卵检查采用饱和硫酸镁离心漂浮法,人群土源性线虫检查采用Kato-Katz法。结果4个村共调查1210人,蛔虫、鞭虫、钩虫感染率分别为26.26%、65.26%、1.74%。土壤样本共检查131户,蛔虫卵、鞭虫卵、钩虫卵检出率分别为58.02%、77.86%、3.82%。相关分析表明,4个村人群土源性线虫感染率与土样中土源性线虫卵检出率非常显著正相关(γ=0.995,P<0.01),其中人群蛔虫感染率与土样蛔虫卵检出率显著正相关(γ=0.954,P<0.05),人群鞭虫感染率与土样鞭虫卵检出率非常显著正相关(γ=0.991,P<0.01)。131户农户的菜园、厕所、庭院、客厅的蛔虫卵检出率依次为48.86%、47.53%、45.04%、34.35%,鞭虫卵检出率依次为66.40%、74.23%、54.20%、45.04%。蛔虫卵、鞭虫卵的每克土壤虫卵数均以菜园和厕所较高。土样中还查到其他寄生虫卵和成虫。结论鄱阳湖区进贤县的4个村土壤中土源性线虫卵检出率与人群感染率之间非常显著相关。     

Serological prevalence of echinococcosis and risk factors for infection among children in rural communities of southern Ningxia, China

Objective  To assess the usefulness of serology as an indicator of Echinococcus transmission for developing preventive measures against echinococcosis in rural communities.
Methods  Cross-sectional survey in 2002 among 861 children aged 7 to 18 years in Xiji County, Ningxia, China. Before ultrasound abdominal examination, a questionnaire was used to identify socioeconomic, sanitary and hygiene risk factors for echinococcal infection; filter paper blood samples were collected from each child for specific antibody detection using EmP ( Echinococcus multilocularis ) and EgB ( Echinococcus granulosus ) antigens.
Results  Transmission of both E. multilocularis and E. granulosus occur in this area. Serological prevalence was far higher than disease prevalence in this age range. We found no gender-related differences of seroprevalence among the children, suggesting an equal chance of exposure to echinococcal egg-contaminated environments. The seroprevalence distribution was associated with changes in the ecology of wild hosts for E. multilocularis contamination, and with changes in socio-geographic features of the communities for E. granulosus contamination.
Conclusions  Serological data obtained for children in mass surveys of echinococcosis appear to be a comprehensive and useful tool to monitor changes of transmission dynamics in humans and provide 'warning signals' to decision makers for the instigation of specific control measures against the disease.     

Alarming prevalence of hepatitis-B infection among the Jarawas--a primitive Negrito tribe of Andaman and Nicobar Islands,India

Summary. Jarawas, a classical hunter–gatherer tribe of Andaman and Nicobar islands have lived in isolation for several centuries. It is only recently have they started to come in contact with the outsiders, shedding their hostility. Since then, several disease outbreaks have been reported amongst them. Screening of sera samples collected during one such outbreak showed very high endemicity of hepatitis-B infection with over 60% of the individuals positive for hepatitis B surface antigen (HBsAg). The rates of HBsAg observed among the Jarawas are probably the highest ever reported in the world and warrant immediate control measures which would prevent further spread of this infection in the community.     

Impact of hookworm infection and deworming on anaemia in non‐pregnant populations: a systematic review

Objectives To summarise age‐ and intensity‐stratified associations between human hookworm infection and anaemia and to quantify the impact of treatment with the benzimidazoles, albendazole and mebendazole, on haemoglobin and anaemia in non‐pregnant populations. Methods Electronic databases (MEDLINE, EMBASE, PubMed) were searched for relevant studies published between 1980 and 2009, regardless of language, and researchers contacted about potential data. Haemoglobin concentration (Hb) was compared between uninfected individuals and individuals harbouring hookworm infections of different intensities, expressed as standardised mean differences (SMD) and 95% confidence intervals (CI). Meta‐analysis of randomised control trials (RCTs) investigated the impact of treatment on Hb and anaemia. Results Twenty‐three cross‐sectional studies, six pre‐ and post‐intervention studies and 14 trials were included. Among cross‐sectional studies, moderate‐ and heavy‐intensity hookworm infections were associated with lower Hb in school‐aged children, while all levels of infection intensity were associated with lower Hb in adults. Among RCTs using albendazole, impact of treatment corresponded to a 1.89 g/l increase (95%CI: 0.13–3.63) in mean Hb while mebendazole had no impact. There was a positive impact of 2.37 g/l (95%CI: 1.33–3.50) on mean Hb when albendazole was co‐administered with praziquantel, but no apparent additional benefit of treatment with benzimidazoles combined with iron supplementation. The mean impact of treatment with benzimidazoles alone on moderate anaemia was small (relative risk (RR) 0.87) with a larger effect when combined with praziquantel (RR 0.61). Conclusions Anaemia is most strongly associated with moderate and heavy hookworm infection. The impact of anthelmintic treatment is greatest when albendazole is co‐administered with praziquantel.     

The prevalence and risk factors associated with abusive or hazardous alcohol consumption in 16-year-olds

This paper examines the prevalence of abusive or hazardous alcohol consumption at age 16 years and the risk factors associated with such behaviour using data from a longitudinal study of a birth cohort of 953 children. Drinking behaviour was assessed on the basis of self-report measures of the frequency of alcohol consumption, reports of the typical and largest amounts of alcohol consumed and the frequency of alcohol-related problems. These measures were combined using latent class analysis methods to identify a group of adolescents (9.3% of the sample) who were characterized by high levels of abusive or hazardous drinking behaviour. Analysis of the risk factors associated with abusive/hazardous drinking identified three factors which were predictive of this behaviour at age 16 years: gender (p < 0.001); the largest amount of alcohol consumed at age 14 years (p < 0.05); and the extent of affiliation with substance using peers (p < 0.001). Further analysis suggested that the effects of other social, familial and individual risk factors on alcohol abuse were mediated via their effect on early drinking behaviour or via their influences on peer affiliations in adolescence. A tentative model of the pathways to adolescent alcohol abuse is discussed.     

The prevalence of diabetes complications and associated risk factors in Pacific Islands countries

Aim

To determine the prevalence of diabetes complications and associated risk factors among people with type 2 diabetes in three Pacific Island countries, Nauru, Solomon Islands and Vanuatu.

Methods

This cross-sectional study was carried out on a sample of 459 people with diabetes. Subjects were screened for complications using a standardised protocol which gathered information on demographics, physical and biochemical parameters.

Results

Of the 459 subjects, 47% were female, mean age was 54 years and mean duration of diabetes was eight years. The prevalence of diabetes complications was significantly higher in Nauru compared with the Solomon Islands and Vanuatu – microalbuminuria 71%, 36% and 51% respectively (P < 0.001), retinopathy 69%, 40% and 42% respectively (P < 0.001), and abnormal foot sensation 30%, 23% and 19% respectively (P = 0.036). The prevalences of hypertension, overweight/obesity and poor glycaemic control were high. The percentages of subjects achieving recommended clinical targets were low. Microalbuminuria was significantly associated with duration of diabetes, hypertension and glycaemic control. Diabetic retinopathy was significantly associated with duration of diabetes whereas abnormal foot sensation was significantly associated with duration of diabetes and glycaemic control.

Conclusions

This study found a high prevalence of diabetes complications and associated risk factors, which indicate the need to improve diabetes care and strengthen preventive efforts to reduce complications.     

High incidence and prevalence of HIV-1 infection in high risk population in Calcutta,India

HIV-1 infection in India has been increasing steadily over the last decade. In the absence of potent antiviral therapy, estimates of HIV infection are needed to monitor the epidemic, institute prevention strategies in target populations and determine the suitable populations for vaccine studies. In this report we present the HIV-1 seroprevalence and annual estimates of seroincidence in a high risk population from Calcutta, the most populous city in the eastern part of India. In 1206 high risk subjects tested over two years between February of 1999 and December 2000, we have determined an overall seroprevalence of 40.1% using enzyme-linked immunosorbent assay followed by a confirmatory Western blot testing. Furthermore, using a newly described Standardized Testing Algorithm for Recent HIV-1 Seroconversion (STARHS), we have estimated an annual seroincidence rate of about 7% in this population during this two-year study. Such a high annual seroincidence rate makes this population well suited for studies of HIV-1 prevention, including vaccine trials.