Use of bed nets and factors that influence bed net use among Jinuo Ethnic Minority in southern China

G-formula for observational studies under stratified interference, with application to bed net use on malaria

Assessing population-level effects of vaccines and other infectious disease prevention measures is important to the field of public health. In infectious disease studies, one person's treatment may affect another individual's outcome, that is, there may be interference between units. For example, the use of bed nets to prevent malaria by one individual may have an indirect effect on other individuals living in close proximity. In some settings, individuals may form groups or clusters where interference only occurs within groups, that is, there is partial interference. Inverse probability weighted estimators have previously been developed for observational studies with partial interference. Unfortunately, these estimators are not well suited for studies with large clusters. Therefore, in this paper, the parametric g-formula is extended to allow for partial interference. G-formula estimators are proposed for overall effects, effects when treated, and effects when untreated. The proposed estimators can accommodate large clusters and do not suffer from the g-null paradox that may occur in the absence of interference. The large sample properties of the proposed estimators are derived assuming no unmeasured confounders and that the partial interference takes a particular form (referred to as 'weak stratified interference'). Simulation studies are presented demonstrating the finite-sample performance of the proposed estimators. The Demographic and Health Survey from the Democratic Republic of the Congo is then analyzed using the proposed g-formula estimators to assess the effects of bed net use on malaria.

Utilization of insecticide-treated bed nets among pregnant women in Myanmar–analysis of the 2015–2016 Demographic and Health Survey

Background

Due to the effectiveness of insecticide-treated nets (ITNs), most malaria-endemic countries resort to free distributions in the population with particular attention to pregnant women, a more vulnerable group. However, the mere issuance of ITNs does not usually translate to proper utilization. This study aimed to examine the utilization of ITNs and its associated factors among pregnant women in Myanmar.

Methods

The data analyzed in this cross-sectional study were extracted from available survey datasets of the 2015–16 Myanmar Demographic Health Survey. The secondary data were presented using a chart, descriptive statistics and inferential statistics including simple and multiple logistic regression models. All analyses were performed using STATA, Version 15. A p-value <0.05 was considered statistically significant.

Results

Of 466 currently pregnant women, the majority (96%) possessed bed nets for sleeping. Among them, 15.9% slept without a bed net the night before the survey, while 65.7% slept with untreated nets. Only about 1 in 5 (18.4%) slept under ITNs. In the multivariate logistic regression analysis, pregnant women residing in delta and lowland regions [adjusted odds ratio (aOR) = 7.70, 95% confidence interval (CI): 3.62, 16.38], plains (aOR = 7.09, 95%CI: 3.09, 16.25) or hilly areas (aOR = 4.26, 95%CI: 1.91, 9.52) were more likely to report non-utilization of ITNs than those residing in coastal regions.

Conclusion

Relatively poor ITN utilization was observed among pregnant women in Myanmar. Health promotion activities for ITN utilization should be implemented especially for pregnant women residing in the delta, lowland, plain and hilly regions. Other social-behavioral factors including perceived susceptibility to malaria, knowledge of ITNs, and attitude towards ITN that might favor the non-utilization of ITNs need to be further explored.

Knowledge, Attitude, and Practice towards Malaria among People Attending Mekaneeyesus Primary Hospital, South Gondar, Northwestern Ethiopia: A Cross-Sectional Study

Background

Malaria is one of the most severe public health problems worldwide. It is a leading cause of suffering, death, and socioeconomic problem, especially in many developing countries like Ethiopia. To introduce appropriate preventive and control measures, assessment of community's levels of knowledge, attitude, and preventative practices regarding malaria is crucial. This study was aimed at assessing the knowledge, attitude, and practice (KAP) towards malaria and its preventive and control methods among people attending Mekaneeyesus primary hospital, South Gondar, northwestern Ethiopia.

Methods

A hospital-based cross-sectional study was conducted from September 2017 to April 2018. A structured questionnaire was administered to collect data on sociodemographic characteristics and KAP of 390 randomly selected individuals. The data collecting tool was pretested before commencing the actual data collection. The data were analyzed using the SPSS version 21 software. P values less than 0.05 were considered statistically significant.

Results

The overall prevalence rate of malaria in the study area was 8.5%. Nearly two-third of the participants had good knowledge (63.1%) and positive attitude (62.6%) scores towards malaria while only half of the participants had (50.8%) good practice score towards malaria prevention and control measures. Sex, age category, family monthly income, residence, and occupational and educational status of the participants were significantly associated with knowledge and practice scores (P < 0.05). The odds of malaria were 26.93 (CI = 3.67‐197.47, P = 0.001) and 13.09 (CI = 0.93‐183.47, P = 0.036) times higher among individuals who had poor knowledge and poor practice towards malaria, respectively, as compared to individuals who were knowledgeable and had good practice score towards malaria.

Conclusion

The overall knowledge score, attitude, and practice level of respondents towards malaria was relatively good. However, significant proportion of the participants still have misconception about the cause, sign and symptoms, modes of transmission, and practices towards prevention methods of malaria. Thus, health education which is aimed at raising community's awareness about the disease is necessary to address the gaps identified by this study.

Comparing insecticide-treated nets access-use based on universal household and population indicators vis-a-vis measures adapted to sleeping spaces in Ethiopia

Background

Insecticide-treated nets (ITNs) access-use has been pivotal monitoring indicator for malaria prevention and control, particularly in resource limited settings. The objective of the study was to compare ITN access-use based on universal household and population indicators and measures adapted to sleeping spaces.

Methods

A cross-sectional study was conducted in five districts of Jimma Zone, Ethiopia, March, 2019. 762 HHs were sampled for the survey. Multi-stage followed by simple random sampling used. Monitoring and evaluation reference group’s (MERG’s) indicators were used for measuring ITN access-use. MERG’s indicators are each adapted ITN access-use to sleeping spaces. Household (ownership, saturation and sufficiency) and population access and household members’ status of last night sleeping under ITN compared based on the two models. Differences of estimates of ITN access-use based on the two methods reported as magnitude of over/under estimations, at p-value < 0.05.

Results

Based on MERG’s approach, the study revealed household (HH) based indicators as such: HH ownership of at least 1 ITN (92.6%), sufficiency of ITN for every two people in HH (50.3%), and saturation of ITN for every 2 people in HHs with any ITN (54.6%). Moreover, population based indicators were: population with ITN access (P3 = 78.6%), people who slept under ITN previous night (63.0%), people who slept under ITN among who accessed it (73.1%), ITN use-gap (26.9%). Equivalent indicators of HH ownership, sufficiency, saturation, and people accessed at where they actually slept, and people slept under ITN among those accessed at where they slept estimated at 71.3%, 49.4%, 69.3%, 66.3%, and 92.1%, respectively. MERG’s approach over-estimated ownership, people’s access, and behaviour-failures by 21.3%, 12.3%, 19.0%, respectively. Over-estimation occurred for reasons such as many sleeping spaces lack ITN and > 2 people actually slept per sleeping space.

Conclusions

MERG’s universal indicators over estimated households and populations ITN access-use as a result of absence of measures capturing access-use values at spaces where people actually slept. Consequently, measures adapted to sleeping contexts revealed potential misdistributions practiced when the existing indicators are in use. Insertion of sleeping spaces into existing approach will be worthwhile and needs to be promoted as it improves curiosity in ITN distribution, produces closer estimates and prevents malaria prevention and control programmes from overlooking access-use challenges.

Ownership and utilization of bed nets and reasons for use or non-use of bed nets among community members at risk of malaria along the Thai-Myanmar border

Background

With the goal for malaria elimination in Thailand set for 2024, increased coverage and utilization of bed net, especially insecticide-treated net (ITN) or long-lasting insecticidal net (LLIN) is a key strategy. This study aims to provide the necessary information about bed net ownership and utilization among the population at risk of malaria living along the Thai-Myanmar border in Tak province.

Methods

A cross-sectional study was conducted using a mixed-method approach in 331 households from 5 hamlets in the villages of the Thai-Myanmar border. The research tools included a questionnaire, bed net inspection, and semi-structured interviews. Logistic regression was used to explore the sociodemographic factors associated with bed net utilization. The qualitative analysis employed a thematic analysis approach.

Results

This survey found that 98.5% of households had at least one bed net per household, and 74.3% had at least one ITN/LLIN. However, only 30.8% of households reached the standard policy set by the Minister of Public Health of one ITN/LLINs per two persons. Most residents used bed net (92.1% used in the previous night and 80.9% used every day). For those using bed nets, however, 61.9% used ITNs or LLINs the night before and 53.1% used them every day. Nonetheless, the usage rates of bed nets (any type) in the previous night among children and pregnant women were high, reaching 95.3% and 90.0%, respectively. Seven explanatory variables showed statistically significant associations with bed net use every day, including: “not staying overnight in the forest or the field”, “sleeping pattern based on gender”, “sufficient numbers of bed nets to cover all sleeping spaces”, “preference for free bed nets”, “age”, “gender”, and “SES score” showed statistically significant association with bed net use every day. The major reasons for the regular use of bed nets in both household and the forest were to prevent mosquito biting. The reasons for not using bednets in the household were discomfort feelings from heat, perception of unnecessity due to low mosquito density, whereas the reason for not using bed nets in the forest was inconvenience.

Conclusion

Despite that overall coverage and usage of bed nets was high, only one third reached the standard level specified by the policy. Overnight in the forest, the dissatisfaction with the quality of free bed nets, insufficient number of bed nets, sleeping alone, male gender, age more than 10 years, low socioeconomic status, discomfort from heat, perception of no benefits of bed nets due to low mosquito density, and inconvenience were factors influencing bed net use. Maintaining high coverage and utility rate of bed nets should be a priority for the malaria high-risk population.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12936-021-03837-5.

Seven decades towards malaria elimination in Yunnan, China

BACKGROUND

Yunnan Province was considered the most difficult place in China for malaria elimination because of its complex malaria epidemiology, heterogeneous ecological features, relatively modest economic development, and long, porous border with three malaria endemic countries: Lao People's Democratic Republic, Myanmar, and Viet Nam.

METHODS

Academic publications and grey literature relevant to malaria elimination in Yunnan covering the period from 1950 until 2020 inclusive were considered. The following academic indexes were searched: China Science Periodical Database, China National Knowledge Infrastructure Database, and MEDLINE. Grey literature sources were mainly available from the National Institute of Parasitic Diseases (NIPD), the Chinese Center for Diseases Control and Prevention, and the Yunnan Institute of Parasitic Diseases (YIPD).

RESULTS

A malaria elimination campaign in the 1950-1960s, based mainly on mass administration of antimalarial drugs and large-scale vector control, reduced morbidity and mortality from malaria and interrupted transmission in some areas, although elimination was not achieved. Similar strategies were used to contain outbreaks and a resurgence of disease during the 1970s, when malaria services were discontinued. From the 1980s, malaria incidence declined, despite the challenges of large numbers of mobile and migrant populations and an unstable primary health care system in rural areas following economic transformation. Launch of the national malaria elimination programme in 2010 led to adoption of the '1-3-7' surveillance and response strategy specifying timely detection of and response for every case, supported by the establishment of a real-time web-based disease surveillance system and a new primary health care system in rural areas. Border malaria was addressed in Yunnan by strengthening the surveillance system down to the lowest level, cross-border collaboration with neighbouring countries and non-governmental organizations, and the involvement of other sectors.

CONCLUSIONS

Seven decades of work to eliminate malaria in Yunnan have shown the importance of political commitment, technically sound strategies with high quality implementation, a robust surveillance and response system at all levels, community participation and effective management of border malaria. The experiences and lessons learned from elimination remain important for prevention re-establishment of malaria transmission in the Province.

Ownership and Utilisation of Long-Lasting Insecticidal Nets in Tiko Health District, Southwest Region, Cameroon: A Cross-Sectional Study

INTRODUCTION

Malaria is and remains a serious health concern in Africa. In Cameroon, where malaria is endemic and a major public health problem, the major control measure put in place is the use of long-lasting insecticidal nets (LLINs). In the Tiko Health District (THD), the challenges have been to assess and to evaluate the ownership and utilisation of LLINs. This study sought to assess the ownership and utilisation rates of LLINs in the THD. Methodology. A cross-sectional survey involving 418 households was conducted in four health areas in the THD. A structured questionnaire was used to collect data on LLIN ownership and utilisation as well as sociodemographic characteristics.

RESULTS

The ownership of at least one LLIN per household, coverage, and accessibility were, respectively, 89%, 56.2%, and 66.3%, while installing LLINs on all beds in the household, sleeping under LLINs the previous night (SULPN), and universal utilisation were 72%, 24.9%, and 14.1%, respectively. Factors significantly associated with the ownership of at least one LLIN per household were respondent's age and gender. Heat (21.1%) and forgetfulness (6.5%) were the main reasons postulated for irregular utilisation of LLINs.

CONCLUSION

The ownership LLINs failed to guarantee utilisation and definitely effective control of malaria in the THD, as expected. Continuous and appropriate use of LLINs is indispensable, in addition to periodic sanitation, booster campaigns of LLIN distribution, and evaluation research for effective prevention and control of malaria.

Narrative Review on Health-EDRM Primary Prevention Measures for Vector-Borne Diseases

Climate change is expanding the global at-risk population for vector-borne diseases (VBDs). The World Health Organization (WHO) health emergency and disaster risk management (health-EDRM) framework emphasises the importance of primary prevention of biological hazards and its value in protecting against VBDs. The framework encourages stakeholder coordination and information sharing, though there is still a need to reinforce prevention and recovery within disaster management. This keyword-search based narrative literature review searched databases PubMed, Google Scholar, Embase and Medline between January 2000 and May 2020, and identified 134 publications. In total, 10 health-EDRM primary prevention measures are summarised at three levels (personal, environmental and household). Enabling factor, limiting factors, co-benefits and strength of evidence were identified. Current studies on primary prevention measures for VBDs focus on health risk-reduction, with minimal evaluation of actual disease reduction. Although prevention against mosquito-borne diseases, notably malaria, has been well-studied, research on other vectors and VBDs remains limited. Other gaps included the limited evidence pertaining to prevention in resource-poor settings and the efficacy of alternatives, discrepancies amongst agencies' recommendations, and limited studies on the impact of technological advancements and habitat change on VBD prevalence. Health-EDRM primary prevention measures for VBDs require high-priority research to facilitate multifaceted, multi-sectoral, coordinated responses that will enable effective risk mitigation.

The health beliefs, dengue knowledge and control behaviors among internally displaced persons versus local residents in Kachin Special Region II, Myanmar

Dengue fever (DF) is one of main public health problems along the China-Myanmar border, however, data about DF is still lacking in Kachin Special Region II (KSR2), Myanmar. To understand health beliefs in general, and knowledge and treatment-seeking and prevention behaviors related to DF among the neglected population, the study was carried out by using a combination of quantitative household questionnaire surveys (HHSs) and qualitative semi-structured in-depth interviews (SDIs). The HHS questionnaire was administered to a total of 258 household heads. The 215 (83.3%) HHS respondents believed in Christianity and Catholicism. However, the 141 (54.7%,) of the total respondents thought that people with evil practices might be punished by diseases. More respondents believed that too rainy weather and water were more related to disease in the internally displaced person (IDP) camp than the local community (P<0.01). Most of the HHS respondents had sound knowledge of dengue symptoms, causes, vectors, transmission and prevention. The 257 (99.6%) HHS respondents reported that their families went to the public health facilities first to seek treatment. The 210 (84.1%) respondents reported that they turned containers upside down within five days. The key informants (n = 18) identified that the appropriate knowledge and behaviors were attributable to formal school education and specific health education campaign during the outbreak response in 2017, and that Kachin people enjoy conversing with each other, neighbors talked about the dengue information they received. The study results indicated that Kachin people have a good knowledge and behaviors of dengue control. The actual situation of dengue is still not clear due to lacking data of laboratory test. In the context of resources shortage, more international assistance is still needed to promote local dengue control and prevention efforts.

The conflict between the Kachin Independence Army and the Myanmar government armed forces has lasted for more than eight years in the Kachin State (since 9^th June 2011). Control of vector-borne diseases is especially important in emergency settings of tropical regions. In 2017, a dengue outbreak occurred and then was successfully controlled in Kachin Special Region (KSR2), Myanmar. To understand further preparedness at the community level for future possible re-emergence of DF, one IDP camp and a local community were sampled to investigate people’s health beliefs in general, knowledge and treatment-seeking and prevention behaviors related to dengue control from August to December, the local dengue transmission season in 2018. This study found that the IDPs and local Kachin residents have sound knowledge about dengue, treatment-seeking and prevention behaviors; an inconsistency exists between their religious and health beliefs due to pressure from various diseases and health problems. The community members perceived DF as a serious and life-threatening disease; however, the local health authority did not think dengue was a priority health problem. The actual situation of dengue is still not clear due to lacking laboratory test and surveillance data. In the emergency context, dengue may still be a local health threat and dengue control is particularly important. The local capacity for dengue laboratory testing and control and prevention activities should be promoted urgently. This should get more international attention and assistance.

Treatment seeking behavior and associated factors of suspected dengue fever among Shan people in eastern Shan special region IV, Myanmar: a cross-sectional study

Background

Dengue fever (DF) is a rapidly spreading mosquito-borne disease along the China-Myanmar border. Understanding treatment-seeking behaviors (TSBs) and associated factors of suspected DF patients in local communities helps to improve health services via promoting prompt treatment, improving patients’ prognosis, finding DF information and timely response to DF foci.

Methods

A combination of qualitative semi-structured in-depth interview (SDIs) included 18 key-informants, and quantitative household questionnaire survey (HHSs) involved 259 households was carried out to investigate TSBs and associated factors of suspected DF patients in the Eastern Shan Special Region IV (ESSR4), Myanmar.

Results

The key informants mentioned that most of their fellow villagers did not seek treatment in public health facilities first. The HHS questionnaires were distributed to household heads, and 241 of the 259 HHS respondents were valid after data auditing. Only 102 (43.2%) household heads reported that their family sought treatment for suspected DF at a public health facility immediately; 111 (46.1%) respondents said that they chose self-medication first. The adjusted odds ratio of multivariate logistic analysis (MLA) predicting household heads’ first seeking healthcare at a public hospital were 1.91 (95%CI: 1.03–3.53) for those who knew DF and 5.11 (95%CI: 2.08–12.58) for those who regarded DF as a deadly disease, indicating that families who knew DF and regarded DF as a deadly disease were more likely to seek treatment for suspected DF at a public health facility immediately.

Conclusion

The inappropriateness of treatment-seeking behaviors for suspected DF hinders the improvement of the patient prognosis and dengue control in ESSR4, Myanmar. People’s awareness of the potential seriousness of DF is a factor influencing appropriate healthcare-seeking behavior among Shan People.

Determinants of long-lasting insecticidal net ownership and utilization in malaria transmission regions: evidence from Zimbabwe Demographic and Health Surveys

Background

Long-lasting insecticidal nets (LLINs) were first introduced in 2010 as a vector control intervention, to complement indoor residual spraying, to reduce malaria transmission in Zimbabwe. The objective of this study was to investigate factors that were associated with LLIN ownership and utilization among households in malaria transmission regions of Zimbabwe.

Methods

A secondary analysis of cross sectional data from the Zimbabwe demographic and health survey (ZDHS) conducted in 2010 and 2015 surveys round was conducted. The analysis used household-level datasets from across the country to generate evidence for the study. Univariate analysis was used to yield descriptive statistics. Principal component analysis (PCA) was used to calculate wealth quintiles. Binary logistic regression approach was used to identify determinants of LLIN ownership and utilization after controlling for other factors. Data analyses were conducted using STATA version 14 software.

Results

There were no major changes in demographic characteristics of households sampled between 2010 and 2015 survey cycles. LLIN ownership increased significantly by 42 percentage points from 2010 to 2015. There was a tremendous increase in universal coverage of LLINs between 2010 and 2015. The overall utilization levels of LLINs among children under-5 years decreased by 11 percentage points between 2010 and 2015. LLIN usage amongst households followed the same trend with that of the under-fives. Using logistic regression model for 2015 data, region/province, type of place of residence, availability of electricity, radio, roof type, gender of head of household, having telephone, type of cooking fuel, presence of mobile phone, owning a bank account, IRS spraying in the previous 12 months, wealth index, and satellite television decorder were independently associated with net ownership among households. Type of place of residence, age of household head, type of cooking fuel, IRS in previous 12 months, and pregnancy were associated with LLIN utilization.

Conclusion

This study revealed increasing LLIN coverage and low usage in malaria-transmission regions of Zimbabwe. Strengthening of LLIN campaigns, social behaviour change communication (SBCC) interventions and programme routine monitoring are recommended.

The Shan people's health beliefs, knowledge and perceptions of dengue in Eastern Shan Special Region IV, Myanmar

Sustainable dengue intervention requires the participation of communities. Therefore, understanding the health beliefs, knowledge and perceptions of dengue among the local people can help to design locally appropriate strategies for effective interventions. A combination of qualitative semi-structured in-depth interviews (SDIs) and quantitative household questionnaire surveys (HHSs) was used to investigate the beliefs, knowledge and perceptions of dengue among the Shan people in Eastern Shan Special Region IV (ESSR4), Myanmar. The SDI was administered to 18 key informants, and the HHS was administered to 259 respondents. Only 14.7% (95% CI: 10.6–19.6%) of the HHS respondents could confirm that mosquitoes transmit dengue; 14.3% (95% CI: 10.3–19.1%) knew that piebald or Aedes mosquitoes transmit dengue; and 24.3% (95% CI: 19.2–30.0%) believed that dengue-transmitting mosquitoes mainly lived in small ponds. Merely ten (0.4%) of the 259 respondents of the HHS thought that dengue-transmitting mosquitoes bite in the day time. The people in the villages where there were outbreaks of dengue had more knowledge about dengue. This study demonstrates that the health beliefs of the Shan people were closely associated with their lifestyles, social and natural environments. To stay healthy, the Shan people clean their houses and surroundings regularly. However, their knowledge about dengue was not adequate for effective dengue control because it was mostly learned from previous dengue experiences and in a context that lacks systematic health education. Thus, in this setting, with a weak public health structure, more international support should be provided to promote the knowledge of the Shan people about dengue and to increase their sensitive awareness to dengue, which might be beneficial for social mobilization and community participation during future dengue prevention.

The burden of dengue has been increasing over the last five decades, and dengue fever (DF) has become one of the most rapidly spreading mosquito-borne diseases. DF has become another disease that threatens public health after malaria has become successfully controlled along the China-Myanmar border. However, it is currently not easy to contain epidemics of the dengue virus. As part of an integrated vector management approach, a community-based method is effective in the prevention of DF by tailoring the approach in a local context. Consequently, mixed methods comprising qualitative semi-structured in-depth interviews (SDIs) and quantitative household questionnaire surveys (HHSs) were used to study the health beliefs, knowledge and perceptions about dengue among the Shan people in Eastern Shan Special Region IV, Myanmar. This study found that the Shan people believed that their health was closely associated with their lifestyle and the social and physical environment in which they lived. Their beliefs originated from their primary social activities and cultural heritage. Most of their knowledge about DF was learned from previous outbreaks and interventions for the disease. The Shan people had a relatively higher level of knowledge about adult mosquito control, which they learned from previous malaria control programs, but they lacked knowledge on DF symptoms, transmission, vectors and Aedes larval breeding sites. Their knowledge about the methods of adult mosquito control could not effectively control DF. More sound health education is urgently needed to increase the local people’s knowledge of dengue and to rouse community awareness and participation in cleaning vector breeding sites. In the context of a lack of the necessary technical and financial resources, these interventions might rely more on international aid and help from neighboring countries, such as China.

Predictors of sleeping under cost-free mosquito bed nets among children under-five years in Mbarara, Uganda: a household survey

BACKGROUND

In 2010, Uganda Malaria Control Programme distributed cost-free mosquito bed nets to households with children under-five years and pregnant women in selected sub-counties. We assessed the factors associated with sleeping under costfree mosquito nets among children under-five years in Nyakayojo sub-county, Mbarara District, Uganda.

METHODS

381 households with at least a child under-five years and benefited from cost-free bed nets in Nyakayojo were randomly selected. Caregivers of children were interviewed using a questionnaire.

RESULTS

74% children slept under bed nets a night before the study. Children from households with ≥2 nets [aOR=1.75; 95% CI: 1.09-2.81, p=0.02], female caregiver [aOR=2.11; 95% CI: 1.16-3.79, p=0.01] and children from households that did not face problems (skin irritation, torn nets, suffocation, night sweating, nasal congestion and candle fire) when sleeping under bed nets [aOR=1.81; 95% CI: 1.10-2.98, p=0.02] were more likely to use nets. Main reason for not sleeping under a net was damage to the net (47.1%).

CONCLUSION

The proportion of children sleeping under nets was comparable to MDG target. Improvements in use of mosquito nets by children can be achieved through increasing number of nets in a household.

Factors associated with caregivers' consistency of use of bed nets in Nigeria: a multilevel multinomial analysis of survey data

Background

Malaria remains endemic in Nigeria despite programmes and policies put in place toward malaria elimination. Long-lasting insecticidal nets have been documented to offer protection from malaria by preventing mosquito bites. While many studies have examined the factors associated with the use of bed nets in Nigeria and across Africa, little information is available on the factors associated with consistency of use of bed nets.

Methods

The data for this study were derived from a household survey conducted in three states in Nigeria (Akwa Ibom, Kebbi and Nasarawa) between July and September 2015 by the Health Communication Capacity Collaborative, a 5-year cooperative agreement supported by the United States Agency for International Development and the US President’s Malaria initiative and led by the Johns Hopkins Center for Communication Programs. The analysis was limited to a total of 3884 men and women selected from 2863 households with at least one bed net. Multilevel multinomial logistic regression was used to assess the factors associated with consistency of use of bed nets.

Results

The findings revealed 43.2% of the respondents use bed nets every night, while 38.4% use bed nets most nights. The factors associated with using a bed net every night rather than rarely or never using a bed net included sociodemographic and household variables (age, gender, religion, household size, net density, and household wealth), ideational variables (perceptions about severity, susceptibility, self-efficacy to use nets, and response-efficacy of bed net; awareness of place of purchase; willingness to pay for bed nets; attitudes towards net use; and descriptive norm about nets), and state of residence. The three study states differ significantly in terms of most of the independent variables included in the estimated model.

Conclusions

The study recommends that efforts designed to promote consistent use of bed nets should be state-specific and include strategies targeting ideational variables. Furthermore, given the significance of unmeasured heterogeneity at the cluster level, strategies to engage and mobilize the community, such as community dialogue, home visits and engaging community leadership, are relevant.

Association between serum somatostatin levels and glucose-lipid metabolism in the Jino ethnic minority and Han Chinese population

We aim to investigate the relationship between serum somatostatin (SST) levels and glucose-lipid metabolism at various stages of glucose tolerance in the Jino ethnic minority (n=111) and Han population (n=113) of Yunnan Province, southwest China. Anthropometric parameters and biochemical traits were measured. Serum SST and plasma glucagon levels were tested. Participants were divided into three subgroups: isolated fasting hyperglycemia (IFH), isolated post challenge hyperglycemia (IPH) and normal glucose tolerance (NGT). SST levels were found lower while glucagon levels were significantly higher in the Jino ethnic with IPH (P=0.0026 and P=0.0069, respectively). Fasting glucose and high density lipoprotein-cholesterol (HDL-C) levels were higher (P=0.0055 and P=0.0021, respectively) and fasting insulin levels and homeostasis model assessments β-cell function were lower (P=0.0479 and P=0.0007, respectively) in the Jino population. After adjusting for confounding factors, the serum SST level was associated with glucagon (P<0.0001) in both populations. The SST level was correlated with fasting Cpeptide (P=0.0267) in Jino and HDL-C levels in Han (P=0.0079). Our findings suggest that serum SST levels and plasma glucagon levels may vary in subjects with IPH between two ethnics.

Monitoring of long-lasting insecticidal nets (LLINs) coverage versus utilization: a community-based survey in malaria endemic villages of Central India

Background

Despite the known effectiveness of long-lasting insecticidal nets (LLINs) in providing protection against malaria, high level of ownership and use are very difficult to achieve and maintain. Nearly 40,000 LLINs were distributed in 2014 as an intervention tool against malaria transmission in 80 villages of Keshkal sub-district in Chhattisgarh, India. This study assessed LLIN coverage, access, utilization pattern, and key determinants for the net use 1 year after mass distribution.

Methods

In 2015, a cross-sectional household survey was carried out in 80 study clusters (whole village or part of village). From each cluster, 40 households were randomly selected and interviewed using a structured questionnaire adapted from the malaria indicator survey of Roll Back Malaria guidelines. Information on demographic characteristics, LLIN ownership, and its use on the night before the survey, and physical condition of LLINs were recorded.

Results

2970 households were interviewed with a total of 15,003 individuals present in the households during the night before the survey. Nearly 98% of households had at least one LLIN and 59.4% of the surveyed population reportedly used an LLIN the previous night. LLIN use varied from 41 to 94% between the study clusters. Nearly 89% of the LLINs were found in good physical condition (without holes). However, proportion of household with at least one LLIN per two persons was only 39%.

Conclusion

Universal coverage of LLINs was inadequate in the study clusters making it difficult for all household members to use an LLIN. LLIN use varied between clusters and was highest in children under 5 years of age. Health education campaigns and creating awareness about the benefit of sleeping under the LLINs in providing protection against malaria is required not only to high risk groups of pregnant women and children below 5 years of age but all the members of the family to have an epidemiological impact of this intervention at the community level. Relatively high net use despite poor access to LLINs indicates an overall desire to use nets when they are available. The main barrier to increased use of nets is the low coverage at household level.

Behaviors Related to Mosquito-Borne Diseases among Different Ethnic Minority Groups along the China-Laos Border Areas

Background: In China, mosquito-borne diseases are most common in the sub-tropical area of Yunnan province. The objective of this study was to examine behaviors related to mosquito-borne diseases in different ethnic minority groups and different socioeconomic groups of people living in this region. Methods: A stratified two-stage cluster sampling technique with probability proportional to size was used in Mengla County, Xishuangbanna Prefecture, Yunnan. Twelve villages were used to recruit adult (≥18 years old) and eight schools were used for children (<18 years old). A questionnaire on behaviors and environment variables related to mosquito-borne diseases was devised. Results: Multiple correspondence analysis (MCA) grouped 20 behaviors into three domains, namely, environmental condition, bed net use behaviors, and repellent use behaviors, respectively. The Han ethnicity had the lowest odds of rearing pigs, their odds being significantly lower than those of Yi and Yao. For bed net use, Dai and other ethnic minority groups were less likely to use bed nets compared to Yi and Yao. The odds of repellent use in the Han ethnicity was lower than in Yi, but higher than in Dai. The Dai group was the most likely ethnicity to use repellents. Farmers were at a higher risk for pig rearing and not using repellents. Education of less than primary school held the lowest odds of pig rearing. Those with low income were at a higher risk for not using bed nets and repellent except in pig rearing. Those with a small family size were at a lower risk for pig rearing. Conclusion: Different ethnic and socioeconomic groups in the study areas require different specific emphases for the prevention of mosquito-borne diseases.

Spatiotemporal Analysis of the Malaria Epidemic in Mainland China, 2004-2014

The purpose of this study is to characterize spatiotemporal heterogeneities in malaria distribution at a provincial level and investigate the association between malaria incidence and climate factors from 2004 to 2014 in China to inform current malaria control efforts. National malaria incidence peaked (4.6/100,000) in 2006 and decreased to a very low level (0.21/100,000) in 2014, and the proportion of imported cases increased from 16.2% in 2004 to 98.2% in 2014. Statistical analyses of global and local spatial autocorrelations and purely spatial scan statistics revealed that malaria was localized in Hainan, Anhui, and Yunnan during 2004-2009 and then gradually shifted and clustered in Yunnan after 2010. Purely temporal clusters shortened to less than 5 months during 2012-2014. The two most likely clusters detected using spatiotemporal analysis occurred in Anhui between July 2005 and November 2007 and Yunnan between January 2010 and June 2012. Correlation coefficients for the association between malaria incidence and climate factors sharply decreased after 2010, and there were zero-month lag effects for climate factors during 2010-2014. Overall, the spatiotemporal distribution of malaria in China changed from relatively scattered (2004-2009) to relatively clustered (2010-2014). As the proportion of imported cases increased, the effect of climate factors on malaria incidence has gradually become weaker since 2011. Therefore, new warning systems should be applied to monitor resurgence and outbreaks of malaria in mainland China, and quarantine at borders should be reinforced to control the increasingly trend of imported malaria cases.

Malaria from hyperendemicity to elimination in Hekou County on China-Vietnam border: an ecological study

BACKGROUND

Malaria control and elimination are challenged by diversity and complexity of the determinants on the international border in the Great Mekong Sub-region. Hekou, a Chinese county on the China-Vietnam border, was used to document Chinese experiences and lessons for malaria control and elimination.

METHODS

The design was an ecological study. Malaria burden before 1951 and procedures of 64 years (1952-2015) from malaria hyperendemicity to elimination are described. Single and bilinear regression analysis was utilized to analyse the relationship between the annual malaria incidence (AMI) and gross domestic product (GDP), urbanization rate, and banana planting area (BPA).

RESULTS

There was a huge malaria burden before 1951. AMI was reduced from 358.62 per 1000 person-years in 1953 to 5.69 per 1000 person-years in 1960. A system of primary health services, comprising three levels of county township hospitals and village health stations maintained malaria control and surveillance activities in changing political and social-economic settings. However, potential under-reported of malaria and market-oriented healthcare led to a malaria epidemic in 1987. Strong political commitment reoriented malaria from a control to an elimination programme. High coverage of malaria intervention and population access to intervention was crucial for malaria control and elimination; meanwhile, AMI was closely associated with socio-economic development, correlation coefficients (R) -0.6845 (95% CI -0.7978, -0.6845) for national GDP, -0.7014 (-0.8093, -0.7014) for national urbanization rate and -0.5563 (-0.7147, -0.3437) for BPA.

CONCLUSIONS

Multifactor, including political commitment, effective interventions, social and economic development and changing ecological environment, and the complicated interactions between these factors contribute to malaria elimination in Hekou County.

Malaria control along China-Myanmar Border during 2007-2013: an integrated impact evaluation

BACKGROUND

Implementing effective interventions remain a lot of difficulties along all border regions. The emergence of artemisinin resistance of Plasmodium falciparum strains in the Greater Mekong Subregion is a matter of great concern. China has effectively controlled cross-border transmission of malaria and artemisinin resistance of P. falciparum along the China-Myanmar border.

METHODS

A combined quantitative and qualitative study was used to collect data, and then an integrated impact evaluation was conducted to malaria control along the China-Myanmar border during 2007-2013.

RESULTS

The parasite prevalence rate (PPR) in the five special regions of Myanmar was decreased from 13.6 % in March 2008 to 1.5 % in November 2013. Compared with the baseline (PPR in March 2008), the risk ratio was only 0.11 [95 % confidence interval (CI), 0.09-0. 14) in November 2013, which is equal to an 89 % reduction in the malaria burden. Annual parasite incidence (API) across 19 Chinese border counties was reduced from 19.6 per 10 000 person-years in 2006 to 0.9 per 10 000 person-years in 2013. Compared with the baseline (API in 2006), the API rate ratio was only 0.05(95 % CI, 0.04-0.05) in 2013, which equates to a reduction of the malaria burden by 95.0 %. Meanwhile, the health service system was strengthened and health inequity of marginalized populations reduced along the international border.

CONCLUSION

The effective collaboration between China, Myanmar and the international non-governmental organization promptly carried out the core interventions through simplified processes. The integrated approaches dramatically decreased malaria burden of Chinese-Myanmar border.

Factors associated with the use of mosquito bed nets: results from two cross-sectional household surveys in Zambézia Province, Mozambique

Background

Malaria remains a major threat to some 3.2 billion persons globally. Malaria contributes heavily to the overall disease burden in Mozambique and is considered endemic. A cornerstone of Mozambique’s vector control strategy has been to strive for universal coverage of insecticide-treated nets (ITN).

Methods

The study is a population-based cross-sectional survey of female heads-of-household in Zambézia Province, Mozambique conducted during August–September, 2010 and April–May, 2014. Analyses accounted for a stratified two-stage cluster sample design. Outcomes of interest included sleeping under a mosquito net during the previous night. Descriptive statistics were calculated for three oversampled districts and for the entire province. Multivariable logistic regression analysis was used to estimate factors associated with both changes over time and increased mosquito bed net usage.

Results

Of the 3916 households interviewed in 2010 and 3906 households in 2014, 64.3 % were in possession of at least one mosquito bed net. A higher proportion of households in Namacurra (90 %) reported possession of a mosquito net, compared to Alto Molócuè (77 %) and Morrumbala (34 %), respectively in 2014. Of pregnant respondents, 58.6 % reported sleeping under a mosquito net the previous night in 2010 compared to 68.4 % in 2014. Fifty percent of children 0–59 months slept under a mosquito net the previous night in 2010 compared to 60 % in 2014. Factors associated with use of a mosquito net for female head-of-household respondents were higher education, understanding Portuguese, larger household size, having electricity in the household, and larger household monthly income. As travel time to a health facility increased (per 1 h), respondents had 13 % lower odds of sleeping under a mosquito net (OR 0.87; 95 % CI 0.74–1.01, p = 0.07). Pregnant women in 2014 had a 2.4 times higher odds of sleeping under a bed net if they lived in Namacurra compared to Alto Molócuè (95 % CI 0.91–6.32, p = 0.002 for district). Higher maternal education, living in Namacurra, and acquisition of mosquito bed nets were associated with a child 0–59 months reporting sleeping under the net in the previous night in 2014.

Conclusions

Intensified focus on the poorest, least educated, and most distant from health services is needed to improve equity of ITN availability and usage. Additionally, while some districts have already surpassed goals in terms of coverage and utilization of ITN, renewed emphasis should be placed on bringing all geographic regions of the province closer to meeting these targets.

Mutation screening for thalassaemia in the Jino ethnic minority population of Yunnan Province, Southwest China

OBJECTIVES

This study aimed to detect α- and β-thalassaemia mutations in the Jino ethnic minority population of Yunnan Province, Southwest China.

DESIGN

A total of 1613 Jino adults were continuously recruited from February 2012 to April 2012. Fasting venous blood samples were obtained to determine haematological variables. Haemoglobin analysis was conducted using high-performance liquid chromatography. Participants with hypochromic microcytic anaemia or positive haemoglobin analysis profiles were confirmed by α- and β-globin genetic testing, including DNA microarray analysis, direct sequencing methods and multiplex gap-PCR assays.

SETTING

Shanghai Diabetes Institute, Shanghai Key Laboratory of Diabetes Mellitus, Shanghai Jiao Tong University Affiliated Sixth People's Hospital.

RESULTS

We found 363 suspected cases by primary screening of haematological variables and haemoglobin analysis. After further genetic testing, four types of α- and β-thalassaemia mutation were detected in 203 out of 363 individuals. Both α(0)- and α(+)-thalassaemia mutations, --(SEA) and -α(3.7), were identified. β-Thalassaemia mutations included CD17 (HBB:c.52A>T) and CD26 (HbE or HBB:c.79G>A). In addition, 13 HbE carriers had coexisting α(0)- or α(+)-thalassaemia deletions. Clinical haematological variables indicated that, in this study, carriers of all thalassaemic genotypes had more severe hypochromic microcytic anaemia than non-thalassaemic individuals.

CONCLUSIONS

Our results provide information on the Jino ethnic minority that may be useful for further genetic counselling, prenatal screening and clinical diagnosis of thalassaemia in this region.

Assuring access to topical mosquito repellents within an intensive distribution scheme: a case study in a remote province of Cambodia

Background

The public health value of a vector control tool depends on its epidemiological efficacy, but also on its ease of implementation. This study describes an intensive distribution scheme of a topical repellent implemented in 2012 and 2013 for the purpose of a cluster-randomized trial using the existing public health system. The trial aimed to assess the effectiveness of repellents in addition to long-lasting insecticidal nets (LLIN) and occurred in a province of Cambodia. Determinants for accessibility and consumption of this tool were explored.

Methods

135 individuals were appointed to be repellent distributors in 57 villages. A 2-weekly bottle exchange programme was organized. Distributors recorded information regarding the amount of bottles exchanged, repellent leftover, and reasons for not complying in household data sheets. Distributor-household contact rates and average 2-weekly consumption of repellent were calculated. Household and distributors characteristics were obtained using questionnaires, surveying 50 households per cluster and all distributors. Regression models were used to explore associations between contact and consumption rates and determinants such as socio-economic status. Operational costs for repellent and net distribution were obtained from the MalaResT project and the provincial health department.

Results

A fourfold increase in distributor-household contact rates was observed in 2013 compared to 2012 (median₂₀₁₂ = 20 %, median₂₀₁₃ = 88.9 %). Consumption rate tripled over the 2-year study period (median₂₀₁₂ = 20 %, median₂₀₁₃ = 57.89 %). Contact rates were found to associate with district, commune and knowing the distributor, while consumption was associated with district and household head occupation. The annual operational cost per capita for repellent distribution was 31 times more expensive than LLIN distribution (USD 4.33 versus USD 0.14).

Discussion

After the existing public health system was reinforced with programmatic and logistic support, an intense 2-weekly distribution scheme of a vector control tool over a 2-year period was operated successfully in the field. Lack of associations with socio-economic status suggested that the free distribution strategy resulted in equitable access to repellents. The operational costs for the repellent distribution and exchange programme were much higher than LLIN distribution. Such effort could only be justified in the context of malaria elimination where these interventions are expected to be limited in time.

Electronic supplementary material

The online version of this article (doi:10.1186/s12936-015-0960-4) contains supplementary material, which is available to authorized users.

Coverage, use and maintenance of bed nets and related influence factors in Kachin Special Region II, northeastern Myanmar

BACKGROUND

Myanmar is one of the 31 highest burden malaria countries worldwide. Scaling up the appropriate use of insecticide-treated nets (ITNs) is a national policy for malaria prevention and control. However, the data on use, influencing factors and maintenance of bed nets is still lack among the population in Kachin Special Region II (KR2), Northeastern Myanmar.

METHODS

The study combined a quantitative household questionnaire survey and qualitative direct observation of households. A Chi-squared test was used to compare the percentages of ownership, coverage, and rates of use of bed nets. Additionally, multivariate logistic regression analysis (MVLRA) was used to analyse factors that influence the use of bed nets. Finally, covariance compared the mean calibrated hole indexes (MCHI) across potential influence variables.

RESULTS

The bed net to person ratio was 1:1.96 (i.e., more than one net for every two people). The long-lasting insecticidal net (LLIN) to person ratio was 1: 2.52. Also, the percentage of households that owned at least one bed net was 99.7% (666/688). Some 3262 (97.3%) residents slept under bed nets the prior night, 2551 (76.1%) of which slept under ITNs/LLINs the prior night (SUITNPN). The poorest families, those with thatched roofing, those who use agriculture as their main source of family income, household heads who knew that mosquitoes transmit malaria and those who used bed nets to prevent malaria, were significantly more likely to be in the SUITNPN group. However, residents in lowlands, and foothills were significantly less likely to be SUITNPNs. Finally, head of household attitude towards fixing bed nets influenced MCHI (F=8.09, P=0.0046).

CONCLUSIONS

The coverage and usage rates of bed nets were high, especially among children, and pregnant women. Family wealth index, geographical zones, household roofing, source of family income, household head's knowledge of malaria transmission and of using bed nets as tools for malaria prevention are all independent factors which influence use of ITNs/LLINs in KR2. Maintaining high coverage, and use rate of bed nets should be a priority for the war-torn population of KR2 to ensure equity and human rights.

Households with Insufficient Bednets in a Village with Sufficient Bednets: Evaluation of Household Bednet Coverage Using Bednet Distribution Index in Xepon District, Lao PDR

In Lao PDR, the National Malaria Control Program (NMCP) evaluates bednet coverage, often at the village level, using a coverage target of one net per 2.5 (or fewer) persons in a given population. However, in villages that meet the target, not all households necessarily meet the target or utilize all available bednets. This study explored households that fell short of the target and household utilization of bednets in villages that met the target of bednet coverage set by the NMCP. The person per net ratio (PPNR), which is defined as the population divided by the number of available bednets in a household/village, was used to determine whether a household/village met the NMCP target. Using a household survey, we collected and analyzed the data of 635 households in 17 villages in Xepon district in 2012. Households that fell short of the target (households with a PPNR of > 2.5 or no bednet) existed in every village. The proportion of these households differed greatly among the villages, ranging from 3.4-50%, with some households falling far short. Of the 635 households, 275 (43.5%) had at least one bednet that was not being used on the night preceding the survey and 131 (20.6%) had at least two. In conclusion, in villages that met the NMCP target, a considerable number of households fell short of the target, and the available bednets were not fully utilized in many of the surveyed households.

In vivo monitoring of dihydroartemisinin-piperaquine sensitivity in Plasmodium falciparum along the China-Myanmar border of Yunnan Province, China from 2007 to 2013

BACKGROUND

Artemisinin-based combination therapy (ACT) is the recommended first-line treatment of falciparum malaria in all endemic countries. Artemisinin resistance in Plasmodium falciparum has been confirmed in the Greater Mekong subregion (GMS). Dihydroartemisinin-piperaquine (DAPQ) is the most commonly used ACT in China. To understand the DAPQ sensitivity of P. falciparum, DAPQ resistance was monitored in vivo along the China-Myanmar border from 2007 to 2013.

METHODS

Eligible patients with mono-infections of P. falciparum were recruited to this study after obtaining full informed consent. DAPQ tablets for different categories of kg body weight ranges were given once a day for three days. Patients were followed up for 42 days. Polymerase chain reaction (PCR) was conducted to distinguish between re-infection and recrudescence, to confirm the Plasmodium species. The data were entered and analysed by the Kaplan-Meier method. Treatment outcome was assessed according to the WHO recommended standards.

RESULTS

243 patients were completed valid follow-up. The fever clearance time (FCT) and asexual parasite clearance times (APCT) were, respectively, 36.5 ± 10.9 and 43.5 ± 11.8 hours, and there was an increasing trend of both FCT (F = 268.41, P < 0.0001) and APCT (F = 88.6, P < 0.0001) from 2007 to 2013. Eight (3.3%, 95% confidence interval, 1.4-6.4%) patients present parasitaemia on day three after medication; however they were spontaneous cure on day four. 241 (99.2%; 95% CI, 97.1-99.9%) of the patients were adequate clinical and parasitological response (ACPR) and the proportions of ACPR had not changed significantly from 2007 to 2013 (X(2) = 2.81, P = 0.7288).

CONCLUSION

In terms of efficacy, DAPQ is still an effective treatment for falciparum malaria. DAPQ sensitivity in P. falciparum had not significantly changed along the China-Myanmar border of Yunnan Province, China. However more attentions should be given to becoming slower fever and parasite clearance.