Cost risk benefit analysis to support chemoprophylaxis policy for travellers to malaria endemic countries

Health problems and exposure to infectious risks in returning humanitarian aid workers

BACKGROUND

Humanitarian aid workers are exposed to deployment-related health threats. Identifying subgroups at a higher risk of infection in this diverse population could help optimize prevention.

METHODS

We carried out a retrospective study based on anonymized data of humanitarian aid workers that visited our clinic for a post-deployment visit between 1 January 2018 and 31 December 2021. We conducted a descriptive analysis of basic demographic data, self-reported risk exposure and health problems encountered during deployment extracted from a standard questionnaire.

RESULTS

The questionnaire was administered to 1238 aid workers during 1529 post-deployment medical consultations. The median age was 37.2 years (IQR 31.7-44.3), and 718/1529 (47.0%) were female aid workers. The median duration of deployment was 6 months (IQR 3-12 months). Most deployments (1321/1529 (86.4%)) were for a medical organization and in Sub-Saharan Africa (73.2%). The most common risk exposures were contact with freshwater in schistosomiasis endemic regions (187/1308 (14.3%)), unprotected sexual contact with a person other than a regular partner (138/1529 (9.0%)), suspected rabies exposure (56/1529 (3.7%)) and accidental exposure to blood (44/1529 (2.9%)). Gastrointestinal problems (487/1529 (31.9%)), malaria (237/1529 (15.5%)) and respiratory tract infections (94/1529 (6,2%)) were the most encountered health problems. Fifteen volunteers (1%) were hospitalized during deployment and 19 (1.2%) repatriated due to health problems. Adherence to malaria chemoprophylaxis was poor, only taken according to the prescription in 355 out of 1225 (29.0%) of aid workers for whom prophylaxis was indicated.

CONCLUSION

Humanitarian aid workers deployed abroad encounter significant rates of health problems and report a high level of risk exposure during their deployment, with the risks being greatest among younger people, those deployed to rural areas, and those working for non-medical organizations. These findings help guide future pre-deployment consultations, to increase awareness and reduce risk behaviour during deployment, as well as focus on adherence to medical advice such as malaria chemoprophylaxis.

Health economic evaluations for Indonesia: a systematic review assessing evidence quality and adherence to the Indonesian Health Technology Assessment (HTA) Guideline

Background

The Government of Indonesia implemented health technology assessment (HTA) to ensure quality and cost control in the National Health Insurance Program (Jaminan Kesehatan Nasional/JKN). The current aim of the study was to improve the usefulness of future economic evaluation for resource allocation by appraising current methodology, reporting, and source of evidence quality of studies.

Methods

The inclusion and exclusion criteria were applied to search for relevant studies using a systematic review. The methodology and reporting adherence were appraised according to Indonesia's HTA Guideline issued in 2017. The differences in adherence before and after the guideline dissemination were compared using Chi-square and Fisher's exact tests for methodology adherence wherever appropriate, and the Mann-Whitney test for reporting adherence. The source of evidence quality was assessed using evidence hierarchy. Two scenarios of the study start date and the guideline dissemination period were tested using sensitivity analyses.

Findings

Eighty-four studies were obtained from PubMed, Embase, Ovid, and two local journals. Only two articles cited the guideline. No statistically significant difference (P > 0.05) was found between the pre-dissemination and post-dissemination period with respect to methodology adherence, except for outcome choice. Studies during the post-dissemination period showed a higher score for reporting which was statistically significant (P = 0.01). However, the sensitivity analyses revealed no statistically significant difference (P > 0.05) in methodology (except for modelling type, P = 0.03) and reporting adherence between the two periods.

Interpretation

The guideline did not impact the methodology and reporting standard used in the included studies. Recommendations were provided to improve the usefulness of economic evaluations for Indonesia.

Funding

The Access and Delivery Partnership (ADP) hosted by the United Nations Development Programme (UNDP) and the Health Systems Research Institute (HSRI).

The risk of malaria infection for travelers visiting the Brazilian Amazonian region: A mathematical modeling approach

BACKGROUND

Human mobility between malaria endemic and malaria-free areas can hinder control and elimination efforts in the Amazon basin, maintaining Plasmodium circulation and introduction to new areas.

METHODS

The analysis begins by estimating the incidence of malaria in areas of interest. Then, the risk of infection as a function of the duration of stay after t₀ was calculated as the number of infected travelers over the number of arrived travelers. Differential equations were employed to estimate the risk of nonimmune travelers acquiring malaria in Amazonian municipalities. Risk was calculated as a result of the force of the infection in terms of local dynamics per time of arrival and duration of visit.

RESULTS

Maximum risk occurred at the peak or at the end of the rainy season and it was nonlinearly (exponentially) correlated with the fraction of infected mosquitoes. Relationship between the risk of malaria and duration of visit was linear and positively correlated. Relationship between the risk of malaria and the time of arrival in the municipality was dependent on local effects of seasonality.

CONCLUSIONS

The risk of nonimmune travelers acquiring malaria is not negligible and can maintain regional circulation of parasites, propagating introductions in areas where malaria has been eliminated.

Risk of malaria associated with travel to malaria-endemic areas to visit friends and relatives: a population-based case-control study

BACKGROUND

Reports relying on population-based data and using epidemiologic methodologies such as case-control study designs for malaria in travellers and multivariable regression analysis of risk factors are rare. The aim of this study was to investigate the epidemiologic characteristics of travellers who tested positive for malaria after visiting friends and relatives in malaria-endemic areas to determine the risk of malaria associated with such travel.

METHODS

Using routinely collected data from a population-based laboratory database, we conducted a case-control study of symptomatic people returning from travel to malaria-endemic areas who presented for malaria testing in Calgary from 2013 to 2017. We used a multivariable logistic regression to analyze the association between the presence of malaria and other risk factors.

RESULTS

There were 251 confirmed malaria cases during the study period, of which 219 were matched to 1129 returning travellers without malaria. Based on the multivariable regression, the odds of a traveller who visited friends and relatives in malariaendemic areas being diagnosed with malaria was 2.82 (95% confidence interval [CI] 1.42-5.92) times greater than that of other travellers to these regions. Adults (odds ratio [OR] 3.62, 95% CI 1.66-8.84), males (OR 2.70, 95% CI 1.56-4.80), travellers to Africa (OR 11.52, 95% CI 6.33-22.05) and those who did not seek pretravel advice (OR 0.38, 95% CI 0.20-0.70) were more likely to be diagnosed with malaria. Although those travelling to visit friends and relatives tended to stay longer in endemic areas than other travellers, visit duration was not associated with an increased likelihood of malaria in the model. The annual incidence of malaria was highest (13.34 per 100 000) in metropolitan wards associated with lower socioeconomic status and immigrant communities.

INTERPRETATION

Travellers who visited friends and relatives in malaria-endemic areas were less likely than other travellers to these regions to seek pretravel advice, take prophylaxis and have a visit duration less than 2 weeks; travelling to Africa and being male increased the odds of being diagnosed with malaria, independent of other factors. These data suggest that targeted strategies to provide pretravel care to travellers who visit friends and relatives in malaria-endemic areas may aid in reducing the burden of malaria in this population.

Update: Interim Guidance for Health Care Providers Caring for Pregnant Women with Possible Zika Virus Exposure - United States (Including U.S. Territories), July 2017

CDC has updated the interim guidance for U.S. health care providers caring for pregnant women with possible Zika virus exposure in response to 1) declining prevalence of Zika virus disease in the World Health Organization's Region of the Americas (Americas) and 2) emerging evidence indicating prolonged detection of Zika virus immunoglobulin M (IgM) antibodies. Zika virus cases were first reported in the Americas during 2015-2016; however, the incidence of Zika virus disease has since declined. As the prevalence of Zika virus disease declines, the likelihood of false-positive test results increases. In addition, emerging epidemiologic and laboratory data indicate that, as is the case with other flaviviruses, Zika virus IgM antibodies can persist beyond 12 weeks after infection. Therefore, IgM test results cannot always reliably distinguish between an infection that occurred during the current pregnancy and one that occurred before the current pregnancy, particularly for women with possible Zika virus exposure before the current pregnancy. These limitations should be considered when counseling pregnant women about the risks and benefits of testing for Zika virus infection during pregnancy. This updated guidance emphasizes a shared decision-making model for testing and screening pregnant women, one in which patients and providers work together to make decisions about testing and care plans based on patient preferences and values, clinical judgment, and a balanced assessment of risks and expected outcomes.

On the origin and timing of Zika virus introduction in Brazil

The timing and origin of Zika virus (ZIKV) introduction in Brazil has been the subject of controversy. Initially, it was assumed that the virus was introduced during the FIFA World Cup in June-July 2014. Then, it was speculated that ZIKV may have been introduced by athletes from French Polynesia (FP) who competed in a canoe race in Rio de Janeiro in August 2014. We attempted to apply mathematical models to determine the most likely time window of ZIKV introduction in Brazil. Given that the timing and origin of ZIKV introduction in Brazil may be a politically sensitive issue, its determination (or the provision of a plausible hypothesis) may help to prevent undeserved blame. We used a simple mathematical model to estimate the force of infection and the corresponding individual probability of being infected with ZIKV in FP. Taking into account the air travel volume from FP to Brazil between October 2013 and March 2014, we estimated the expected number of infected travellers arriving at Brazilian airports during that period. During the period between December 2013 and February 2014, 51 individuals travelled from FP airports to 11 Brazilian cities. Basing on the calculated force of ZIKV infection (the per capita rate of new infections per time unit) and risk of infection (probability of at least one new infection), we estimated that 18 (95% CI 12-22) individuals who arrived in seven of the evaluated cities were infected. When basic ZIKV reproduction numbers greater than one were assumed in the seven evaluated cities, ZIKV could have been introduced in any one of the cities. Based on the force of infection in FP, basic reproduction ZIKV number in selected Brazilian cities, and estimated travel volume, we concluded that ZIKV was most likely introduced and established in Brazil by infected travellers arriving from FP in the period between October 2013 and March 2014, which was prior to the two aforementioned sporting events.

Cost-effectiveness analysis of rapid diagnostic tests for G6PD deficiency in patients with Plasmodium vivax malaria in the Brazilian Amazon

BACKGROUND

The use of primaquine (PQ) for radical treatment of Plasmodium vivax in carriers of G6PD deficiency (G6PDd) constitutes the main factor associated with severe haemolysis in G6PDd. The current study aimed to estimate the incremental cost-effectiveness ratio of using a rapid diagnostic test (RDT) to detect G6PDd in male patients with P. vivax malaria in the Brazilian Amazon, in comparison with the routine indicated by the Programme for Malaria Control, which does not include this evaluation.

METHODS

A cost-effectiveness analysis of estimated RDT use was carried out for the Brazilian Amazon for the year 2013, considering the perspective of the Brazilian Public Health System. Using decision trees, estimates were compared for two different RDT strategies for G6PDd in male individuals infected with P. vivax before being prescribed PQ, with the routine indicated in Brazil, which does not include prior diagnosis of G6PDd. The first strategy considered the combined use of RDT BinaxNOW(®) G6PD (BX-G6PD) in municipalities with more than 100,000 inhabitants and the routine programme (RP) for the other municipalities. Operational limitations related to the required temperature control and venous blood collection currently restrict the use of RDT BX-G6PD in small municipalities. The second strategy considered the use of the RDT CareStart™ G6PD (CS-G6PD) in 100 % of the municipalities. The analysis was carried out for the outcomes: "adequately diagnosed case" and "hospitalization avoided".

RESULTS

For the outcome "adequately diagnosed case", comparing the RDT strategies based on RDT with the routine control programme (RP), the CS-G6PD strategy was the most cost-effective, with BX-G6PD extendedly dominating (the ICER of BX-G6PD compared with RP was higher than the ICER of CS-G6PD compared with RP). CS-G6PD dominated the other strategies for the "hospitalization avoided" outcome.

CONCLUSION

The CS-G6PD strategy is cost-effective for adequately diagnosing cases and avoiding hospitalization. This information can help in decision-making, both in incorporating prior diagnosis in the use of PQ and to promote greater safety among G6PD deficient individuals in the Brazilian Amazon P. vivax endemic areas.

A Systematic Review of the State of Economic Evaluation for Health Care in India

BACKGROUND AND OBJECTIVE

Economic evaluations are one of the important tools in policy making for rational allocation of resources. Given the very low public investment in the health sector in India, it is critical that resources are used wisely on interventions proven to yield best results. Hence, we undertook this study to assess the extent and quality of evidence for economic evaluation of health-care interventions and programmes in India.

METHODS

A comprehensive search was conducted to search for published full economic evaluations pertaining to India and addressing a health-related intervention or programme. PubMed, Scopus, Embase, ScienceDirect, and York CRD database and websites of important research agencies were identified to search for economic evaluations published from January 1980 to the middle of November 2014. Two researchers independently assessed the quality of the studies based on Drummond and modelling checklist.

RESULTS

Out of a total of 5013 articles enlisted after literature search, a total of 104 met the inclusion criteria for this systematic review. The majority of these papers were cost-effectiveness studies (64%), led by a clinician or public-health professional (77%), using decision analysis-based methods (59%), published in an international journal (80%) and addressing communicable diseases (58%). In addition, 42% were funded by an international funding agency or UN/bilateral aid agency, and 30% focussed on pharmaceuticals. The average quality score of these full economic evaluations was 65.1%. The major limitation was the inability to address uncertainties involved in modelling as only about one-third of the studies assessed modelling structural uncertainties (33%), or ran sub-group analyses to account for heterogeneity (36.5%) or analysed methodological uncertainty (32%).

CONCLUSION

The existing literature on economic evaluations in India is inadequate to feed into sound policy making. There is an urgent need to generate awareness within the government of how economic evaluation can inform and benefit policy making, and at the same time build capacity of health-care professionals in understanding the economic principles of health-care delivery system.

Low and Declining Risk for Malaria in Visitors to Indonesia: A Review of Local Indonesian and European Travelers' Data and a Suggestion for New Prophylactic Guidelines

INTRODUCTION

The world's malaria map is constantly changing and with it the risk for travelers to contract malaria. While some efforts to appreciate the malaria situation for indigenous populations in Indonesia have been made recently, there is only sparse data in the literature on the risk for travelers to Indonesia.

METHODS

Data were collected from the Indonesian Ministry of Health (MoH), the World Health Organization (WHO), the Indonesian official statistics website Badan Pusat Statistik (BPS), and from the different European national surveillance bodies. Finally, a comparison between recent official guidelines for prevention of malaria in travelers from Germany, the United States, the UK, and from WHO was done.

RESULTS

Data from Denmark, Germany, Sweden and Switzerland show a steady decline of imported cases of malaria from Indonesia from 1997 to 2013, with a leveling off during the last few years. In our study material, the Plasmodium falciparum incidence 2009 to 2013 was 0.35 cases per 100,000 visits and the Plasmodium vivax incidence 1.3 cases per 100,000 visits, with a 95% confidence interval of 0.1-0.9 and 0.7-2.2, respectively. Indonesian data also show a decline of malaria cases-the Annual Parasite Index (API) for all species of malaria has decreased from 4.68 cases per 1,000 inhabitants in 1990 to 1.38 cases per 1,000 inhabitants in 2013.

CONCLUSION

Based on these data updated recommendations for malaria prophylaxis in travelers to Indonesia are suggested.

Risk factors for UK Plasmodium falciparum cases

BACKGROUND

An increasing proportion of malaria cases diagnosed in UK residents with a history of travel to malaria endemic areas are due to Plasmodium falciparum.

METHODS

In order to identify travellers at most risk of acquiring malaria a proportional hazards model was used to estimate the risk of acquiring malaria stratified by purpose of travel and age whilst adjusting for entomological inoculation rate (EIR) and duration of stay in endemic countries.

RESULTS

Travellers visiting friends and relatives and business travellers were found to have significantly higher hazard of acquiring malaria (adjusted hazard ratio (HR) relative to that of holiday makers 7.4, 95% CI 6.4-8.5, p < 0. 0001 and HR 3.4, 95% CI 2.9-3.8, p < 0. 0001, respectively). All age-groups were at lower risk than children aged 0-15 years.

CONCLUSIONS

These estimates of the increased risk for business travellers and those visiting friends and relatives should be used to inform programmes to improve awareness of the risks of malaria when travelling.

Risk assessment and prevention of malaria among Italian troops in Afghanistan, 2002 to 2011

BACKGROUND

Malaria prevention policy is different among coalition troops in Afghanistan, ranging from the combined use of suppressive and terminal chemoprophylaxis to the absence of any prophylactic regimen. The objective of this study was to assess the compliance with malaria prevention measures and the risk of malaria among Italian troops in Afghanistan.

METHODS

Target population was the cohort of 32,500 army soldiers deployed in Afghanistan, 2002 to 2011; eligible subjects were the 21,900 soldiers stationed in endemic areas, who were prescribed mefloquine chemoprophylaxis. Adherence to chemoprophylaxis was assessed by a cross-sectional study in a volunteer sample of 5,773 (26.4%) of eligible subjects. The risk of malaria was assessed by detecting malaria cases in the target population.

RESULTS

Mefloquine chemoprophylaxis was administered to 4,123 (71.4%) of the 5,773 enrolled soldiers and 3,575 (86.7%) of these took it regularly; however, compliance dropped from 80.9% (2,592/3,202) in 2002 to 2006 to 59.5% (1,531/2,571) in 2007 to 2011 (p < 0.01). Adverse events were reported by 875 (21.2%) of the 4,123 soldiers taking mefloquine, but caused irregularity or interruption of chemoprophylaxis only in 48 (1.2%) and 113 (2.7%) subjects, respectively. No serious adverse events were reported. No malaria cases occurred in Afghanistan, and one Plasmodium vivax case was reported in Italy, yielding an incidence rate of 3.24 cases per 10,000 person-months of exposure (1/3,091) during the transmission season of 2003.

CONCLUSIONS

In spite of the decreasing compliance with chemoprophylaxis, suggesting a low perception of the risk of malaria, this study confirmed the good tolerability of mefloquine in the military. The risk of malaria for Italian troops in Afghanistan was very low, and chemoprophylaxis was suspended in 2012. A similar policy may be adopted by the generality of International Security Assistance Force troops, and any chemoprophylaxis may be restricted to soldiers stationing in areas where the risk of malaria is substantial.

Economics of malaria prevention in US travelers to West Africa

Background. Pretravel health consultations help international travelers manage travel-related illness risks through education, vaccination, and medication. This study evaluated costs and benefits of that portion of the health consultation associated with malaria prevention provided to US travelers bound for West Africa.

Methods. The estimated change in disease risk and associated costs and benefits resulting from traveler adherence to malaria chemoprophylaxis were calculated from 2 perspectives: the healthcare payer's and the traveler's. We used data from the Global TravEpiNet network of US travel clinics that collect de-identified pretravel data for international travelers. Disease risk and chemoprophylaxis effectiveness were estimated from published medical reports. Direct medical costs were obtained from the Nationwide Inpatient Sample and published literature.

Results. We analyzed 1029 records from January 2009 to January 2011. Assuming full adherence to chemoprophylaxis regimens, consultations saved healthcare payers a per-traveler average of $14 (9-day trip) to $372 (30-day trip). For travelers, consultations resulted in a range of net cost of $20 (9-day trip) to a net savings of $32 (30-day trip). Differences were mostly driven by risk of malaria in the destination country.

Conclusions. Our model suggests that healthcare payers save money for short- and longer-term trips, and that travelers save money for longer trips when travelers adhere to malaria recommendations and prophylactic regimens in West Africa. This is a potential incentive to healthcare payers to offer consistent pretravel preventive care to travelers. This financial benefit complements the medical benefit of reducing the risk of malaria.

Expatriates: special considerations in pretravel preparation

Expatriates comprise a diverse set of travelers who face unique medical, psychiatric, and non-health-related risks as a result of increased exposure to host country environment and associated lifestyle. Expatriates have an increased risk of developing malaria, gastrointestinal disorders, latent tuberculosis, vaccine-preventable infections, and psychological disorders, when compared with other travelers, yet the majority of existing pretravel guidelines have been designed to suit the needs of nonexpatriates. Although greater interest in expatriate health issues has led to improved characterization of illness in this population, expatriate-specific risk mitigation strategies-including modifications to chemoprophylaxis recommendations, limiting tuberculosis exposure, and prevention of occupational or sexual blood-borne virus transmission-are poorly described. Occupations and destinations affect travel-related disease risk and should inform the pretravel consultation.

Does public subsidy of the cost of malaria chemoprophylaxis reduce imported malaria? A comparative policy analysis

Background

Chemoprophylaxis is recommended for at-risk travellers visiting malaria endemic regions. The majority of travellers with imported malaria have not used this, and travellers visiting friends and relatives have the largest burden of malaria and the lowest compliance to chemoprophylaxis. In 1995, the UK’s Department of Health (DH) implemented a policy to make travellers fully responsible for the cost when purchasing chemoprophylaxis. This policy was not implemented in three Primary Care Trusts (PCTs) in London due to concern about the potential increase of imported malaria in their residents, and they maintained the public subsidy. An impact evaluation of the policy change was undertaken to determine if the continued subsidy reduced the incidence of imported malaria in one of the boroughs where the subsidy was maintained when compared to a borough where no subsidy was provided.

Methods

Between 2007 and 2010 prescriptions for malaria chemoprophylaxis were collected from pharmacy records and PCTs, and all cases of imported malaria reported from the tertiary hospital in each of the two boroughs were compared.

Results

The dispensed chemoprophylaxis prescriptions were nearly 8.8 times higher in Lambeth (where subsidized drugs were provided), than in Hackney. A Poisson model revealed significantly fewer reports of imported malaria per capita were made in Lambeth compared to Hackney (p = 0.042).

Conclusions

The difference in malaria reports between the boroughs only just reached statistical significance, despite the considerable difference in chemoprophylaxis prescribing between the boroughs. Some travellers may not consider using chemoprophylaxis, irrespective of the cost. Regular evaluations of the recent policy changes in areas where malaria is subsidized will be important.

Theoretical impact of insecticide-impregnated school uniforms on dengue incidence in Thai children

Background

Children carry the main burden of morbidity and mortality caused by dengue. Children spend a considerable amount of their day at school; hence strategies that reduce human–mosquito contact to protect against the day-biting habits of Aedes mosquitoes at schools, such as insecticide-impregnated uniforms, could be an effective prevention strategy.

Methodology

We used mathematical models to calculate the risk of dengue infection based on force of infection taking into account the estimated proportion of mosquito bites that occur in school and the proportion of school time that children wear the impregnated uniforms.

Principal findings

The use of insecticide-impregnated uniforms has efficacy varying from around 6% in the most pessimistic estimations, to 55% in the most optimistic scenarios simulated.

Conclusions

Reducing contact between mosquito bites and human hosts via insecticide-treated uniforms during school time is theoretically effective in reducing dengue incidence and may be a valuable additional tool for dengue control in school-aged children. The efficacy of this strategy, however, is dependent on the compliance of the target population in terms of proper and consistent wearing of uniforms and, perhaps more importantly, the proportion of bites inflicted by the Aedes population during school time.

Malaria treatment and prophylaxis in endemic and nonendemic countries: evidence on strategies and their cost–effectiveness

Artemisinin combination treatment is currently the preferred treatment strategy to combat malaria. However, the drug costs are considerably higher than for previously used therapies. This review discusses the cost–effectiveness of current malaria treatment and prophylaxis in endemic and nonendemic countries. For endemic countries, a systematic search for economic evaluations (i.e., cost–effectiveness, cost–utility and cost–benefit analyses) was conducted, looking at the use of Artemisinin combination treatments in children, pregnant women and other adults. In total, 24 studies were identified investigating the cost–effectiveness of malaria treatments with the focus on uncomplicated malaria, severe or prereferral treatment, all in combination with adequate diagnosis, and malaria prevention by intermittent preventive treatment, respectively. In areas with both Plasmodium falciparum and Plasmodium vivax transmission, artemether–lumefantrine and dihydroartemisinin–piperaquine, respectively, are currently the most cost-effective treatment options. Treatment of severe malaria with artesunate is more cost effective compared with treatment with quinine. For patients that live more than 6 h away from an appropriate healthcare facility, prereferral treatment proved to be more cost-effective compared with no prereferral intervention. Cost–effectiveness of intermittent preventive treatment in pregnant women (IPTp) was dependent an clinical attendance. IPT in infants with sulphadoxine–pyrimethamine (SP) is cost effective in sites with high malaria transmission. IPT in children with artesunate (AS + SP), amodiaquine (AQ) + SPQ or SP alone is a cost effective and safe intervention for reducing the burden of malaria in children in areas with markedly seasonal malaria transmission. Although there is a need for it, little is known about the cost–effectiveness of current approaches to malaria therapy in nonendemic countries and the cost–effectiveness of antimalarial chemoprophylaxis.