Neglected tropical diseases of Oceania: review of their prevalence, distribution, and opportunities for control

Coinfection of a yaws patient with two closely related Treponema pallidum subsp. pertenue strains: A rare event with potential evolutionary implications

The etiological agent of yaws is the spirochete Treponema pallidum (TP) subsp. pertenue (TPE) and infects the children of Papua New Guinea, causing ulcerative skin lesions that impairs normal growth and development. Closely related strains of Treponema pallidum subsp. pertenue, JE11, and TE13 were detected in an ulcer biospecimen derived from a 5-year-old yaws patient. Cloning experiments validated the presence of two distinct but similar genotypes, namely TE13 and JE11, co-occurring within a single host. While coinfection with highly related TPE strains has only limited epidemiological and clinical relevance, this is the first documented coinfection with genetically distinct TP strains in a single patient. Similar coinfections in the past were explained by the existence of over a dozen recombinant loci present in the TP genomes as a result of inter-strain or inter-subspecies recombination events following an anticipated scenario of TP coinfection, i.e., uptake of foreign DNA and DNA recombination.

Strongyloidiasis in Auckland: A ten-year retrospective study of diagnosis, treatment and outcomes of a predominantly Polynesian and Fijian migrant cohort

BACKGROUND

Strongyloides stercoralis is not endemic in Aotearoa New Zealand (AoNZ). However, approximately one third of Auckland residents are born in endemic countries. This study aimed to describe the epidemiology and management of strongyloidiasis in Auckland, with a focus on migrants from Pacific Island Countries and Territories.

METHODS

This study retrospectively reviewed clinical, laboratory and pharmacy records data for all people diagnosed with strongyloidiasis in the Auckland region between July 2012 and June 2022. People with negative Strongyloides serology were included to estimate seropositivity rate by country of birth.

FINDINGS

Over ten years, 691 people were diagnosed with strongyloidiasis. Most diagnoses were made by serology alone (622, 90%). The median age was 63 years (range 15-92), 500 (72%) were male, and the majority were born in Polynesia (350, 51%), Fiji (130, 19%) or were of Pasifika ethnicity (an additional 7%). Twelve participants (1.7%) had severe strongyloidiasis at diagnosis. The total proportion treated with ivermectin was only 70% (484/691), with no differences between immunocompromised and immunocompetent participants, nor by ethnicity. The outcome of treatment (based on a combination of serology and/or eosinophilia and/or stool microscopy) could only be determined in 50% of the treated cohort. One participant failed treatment with ivermectin, experiencing recurrent strongyloidiasis, and another participant died in association with severe strongyloidiasis. The rate of 'positive' Strongyloides serology was highest among participants born in Samoa (48%), Fiji (39%), and Southeast Asian countries (34%).

INTERPRETATION

Strongyloidiasis was common and under-treated in Auckland during the study period. Clinicians should have a low threshold for considering strongyloidiasis in migrants from endemic countries, including Polynesia and Fiji.

A Landscape on Lymphatic Filariasis with its Effects and Recent Advanced Treatments

Lymphatic filariasis is an infection caused by parasites that poses a significant health, social, and economic burden, affecting a vast population that exceeds 120 million individuals globally. The Etiology of the infection is attributed to three nematode parasites, namely Wuchereria bancrofti, B. timori, and Brugia malayi, as well as which are phylogenetically related. These parasites are transmitted to humans via mosquitoes belonging to the Anopheles, Aedes genera, and Culex. As per the estimation provided by the WHO, the current number of individuals infected with filariasis stands at approximately 120 million across 81 countries. Furthermore, it is estimated that around 1.34 billion individuals reside in regions that are endemic to filariasis, thereby putting them at risk of contracting the disease. Different synthetic drugs such as Ivermectin, Doxycycline, Albendazole, and Suramin are used in the treatment. Some natural plants are Azadirachta indica, Tinospora cordifolia, Zingiber officinal, as well as, some marine sources are also included for better treatment. We also touch briefly on a few additional filarial diseases. Although there are only a few medications available to treat filariasis, their frequent usage may result in drug resistance. Furthermore, there is no effective vaccination for the treatment of filariasis. Due to these restrictions, it has been crucial to create new anti-filarial medications, which motivates researchers to find novel pharmaceuticals with anti-filarial action. In this article, we examine the latest achievements in the anti-filarial area, including the many forms of filariasis and their historical contexts, elimination programmes, various therapeutic classes (both synthetic and natural), investigated product-derived targets as well as clinical investigations.

Awareness and knowledge of scabies and ringworm among parents of school-age children in Calabar, Cross River State, Nigeria: Implications for prevention of superficial skin infestations

Context

Risk factors for the persistence of superficial skin infestations are prevalent in humid tropical environments, which are favorable for breeding of the causative vector mite Sarcoptes scabiei (ectoparasite) and dermatophyte fungi.

Aim

This study aimed at assessing the awareness and knowledge of childhood scabies and ringworm infestations among parents in Calabar, a highly humid rainforest tropical environment.

Settings and Design

Cross-sectional study design and systematic random sampling were used to recruit school-age children in selected primary schools in Calabar.

Materials and Methods

Researcher-driven administration of a structured questionnaire was conducted to obtain quantitative data from parents of recruited children.

Statistical Analysis Used

: Chi-square was used to assess factors associated with ever hearing or seeing scabies and ringworm infestations. Statistical significance was set at P < 0.05.

Results

One hundred and eighty-two (56.7%) and 218 (67.9%) of the respondents had heard of or seen scabies and ringworm infestation. Among respondents that were aware of scabies, 53.3% knew of the cause, 50.5% were aware of the risk factors while 68.1% and 78.0% knew their treatment and prevention, respectively; 98.6%, 60.6%, 76.6%, and 80.7% of respondents knew the cause, risk factors, treatment, and prevention of ringworm infestation, respectively. Fathers with at least secondary school literacy level and sharing beds were significantly associated with awareness of scabies.

Conclusion

There is a suboptimal level of awareness and knowledge of two of the most common superficial skin infestations among parents of primary school children in the study setting. There is a need to redouble our effort at sensitization of parents toward improved awareness of these common infestations.

Unravelling the determinants of human health in French Polynesia: the MATAEA project

Background

French Polynesia is a French overseas collectivity in the Southeast Pacific, comprising 75 inhabited islands across five archipelagoes. The human settlement of the region corresponds to the last massive migration of humans to empty territories, but its timeline is still debated. Despite their recent population history and geographical isolation, inhabitants of French Polynesia experience health issues similar to those of continental countries. Modern lifestyles and increased longevity have led to a rise in non-communicable diseases (NCDs) such as obesity, diabetes, hypertension, and cardiovascular diseases. Likewise, international trade and people mobility have caused the emergence of communicable diseases (CDs) including mosquito-borne and respiratory diseases. Additionally, chronic pathologies including acute rheumatic fever, liver diseases, and ciguatera, are highly prevalent in French Polynesia. However, data on such diseases are scarce and not representative of the geographic fragmentation of the population.

Objectives

The present project aims to estimate the prevalence of several NCDs and CDs in the population of the five archipelagoes, and identify associated risk factors. Moreover, genetic analyses will contribute to determine the sequence and timings of the peopling history of French Polynesia, and identify causal links between past genetic adaptation to island environments, and present-day susceptibility to certain diseases.

Methods

This cross-sectional survey is based on the random selection of 2,100 adults aged 18-69 years and residing on 18 islands from the five archipelagoes. Each participant answered a questionnaire on a wide range of topics (including demographic characteristics, lifestyle habits and medical history), underwent physical measurements (height, weight, waist circumference, arterial pressure, and skin pigmentation), and provided biological samples (blood, saliva, and stool) for biological, genetic and microbiological analyses.

Conclusion

For the first time in French Polynesia, the present project allows to collect a wide range of data to explore the existence of indicators and/or risk factors for multiple pathologies of public health concern. The results will help health authorities to adapt actions and preventive measures aimed at reducing the incidence of NCDs and CDs. Moreover, the new genomic data generated in this study, combined with anthropological data, will increase our understanding of the peopling history of French Polynesia.

Clinical trial registration

https://clinicaltrials.gov/, identifier: NCT06133400.

Health service needs and perspectives of a rainforest conserving community in Papua New Guinea's Ramu lowlands: a combined clinical and rapid anthropological assessment with parallel treatment of urgent cases

OBJECTIVES

Determine community needs and perspectives as part of planning health service incorporation into Wanang Conservation Area, in support of locally driven sustainable development.

DESIGN

Clinical and rapid anthropological assessment (individual primary care assessments, key informant (KI) interviews, focus groups (FGs), ethnography) with treatment of urgent cases.

SETTING

Wanang (pop. c189), a rainforest community in Madang province, Papua New Guinea.

PARTICIPANTS

129 villagers provided medical histories (54 females (f), 75 males (m); median 19 years, range 1 month to 73 years), 113 had clinical assessments (51f, 62m; median 18 years, range 1 month to 73 years). 26 ≥18 years participated in sex-stratified and age-stratified FGs (f<40 years; m<40 years; f>40 years; m>40 years). Five KIs were interviewed (1f, 4m). Daily ethnographic fieldnotes were recorded.

RESULTS

Of 113 examined, 11 were 'well' (a clinical impression based on declarations of no current illness, medical histories, conversation, no observed disease signs), 62 (30f, 32m) were treated urgently, 31 referred (15f, 16m), indicating considerable unmet need. FGs top-4 ranked health issues concorded with KI views, medical histories and clinical examinations. For example, ethnoclassifications of three ((A) 'malaria', (B) 'sotwin', (C) 'grile') translated to the five biomedical conditions diagnosed most ((A) malaria, 9 villagers; (B) upper respiratory infection, 25; lower respiratory infection, 10; tuberculosis, 9; (C) tinea imbricata, 15) and were highly represented in declared medical histories ((A) 75 participants, (B) 23, (C) 35). However, 29.2% of diagnoses (49/168) were limited to one or two people. Treatment approaches included plant medicines, stored pharmaceuticals, occasionally rituals. Travel to hospital/pharmacy was sometimes undertaken for severe/refractory disease. Service barriers included: no health patrols/accessible aid post, remote hospital, unfamiliarity with institutions and medicine costs. Service introduction priorities were: aid post, vaccinations, transport, perinatal/birth care and family planning.

CONCLUSIONS

This study enabled service planning and demonstrated a need sufficient to acquire funding to establish primary care. In doing so, it aided Wanang's community to develop sustainably, without sacrificing their forest home.

The increasing complexity of arbovirus serology: An in-depth systematic review on cross-reactivity

Diagnosis of arbovirus infection or exposure by antibody testing is becoming increasingly difficult due to global expansion of arboviruses, which induce antibodies that may (cross-)react in serological assays. We provide a systematic review of the current knowledge and knowledge gaps in differential arbovirus serology. The search included Medline, Embase and Web of Science databases and identified 911 publications which were reduced to 102 after exclusion of studies not providing data on possible cross-reactivity or studies that did not meet the inclusion criteria regarding confirmation of virus exposure of reference population sets. Using a scoring system to further assess quality of studies, we show that the majority of the selected papers (N = 102) provides insufficient detail to support conclusions on specificity of serological outcomes with regards to elucidating antibody cross-reactivity. Along with the lack of standardization of assays, metadata such as time of illness onset, vaccination, infection and travel history, age and specificity of serological methods were most frequently missing. Given the critical role of serology for diagnosis and surveillance of arbovirus infections, better standards for reporting, as well as the development of more (standardized) specific serological assays that allow discrimination between exposures to multiple different arboviruses, are a large global unmet need.

Mice as an Animal Model for Japanese Encephalitis Virus Research: Mouse Susceptibility, Infection Route, and Viral Pathogenesis

Japanese encephalitis virus (JEV), a zoonotic flavivirus, is principally transmitted by hematophagous mosquitoes, continually between susceptible animals and incidentally from those animals to humans. For almost a century since its discovery, JEV was geographically confined to the Asia-Pacific region with recurrent sizable outbreaks involving wildlife, livestock, and people. However, over the past decade, it has been detected for the first time in Europe (Italy) and Africa (Angola) but has yet to cause any recognizable outbreaks in humans. JEV infection leads to a broad spectrum of clinical outcomes, ranging from asymptomatic conditions to self-limiting febrile illnesses to life-threatening neurological complications, particularly Japanese encephalitis (JE). No clinically proven antiviral drugs are available to treat the development and progression of JE. There are, however, several live and killed vaccines that have been commercialized to prevent the infection and transmission of JEV, yet this virus remains the main cause of acute encephalitis syndrome with high morbidity and mortality among children in the endemic regions. Therefore, significant research efforts have been directed toward understanding the neuropathogenesis of JE to facilitate the development of effective treatments for the disease. Thus far, multiple laboratory animal models have been established for the study of JEV infection. In this review, we focus on mice, the most extensively used animal model for JEV research, and summarize the major findings on mouse susceptibility, infection route, and viral pathogenesis reported in the past and present, and discuss some unanswered key questions for future studies.

Effects of high temperatures and heatwaves on dengue fever: a systematic review and meta-analysis

BACKGROUND

Studies have shown that dengue virus transmission increases in association with ambient temperature. We performed a systematic review and meta-analysis to assess the effect of both high temperatures and heatwave events on dengue transmission in different climate zones globally.

METHODS

A systematic literature search was conducted in PubMed, Scopus, Embase, and Web of Science from January 1990 to September 20, 2022. We included peer reviewed original observational studies using ecological time series, case crossover, or case series study designs reporting the association of high temperatures and heatwave with dengue and comparing risks over different exposures or time periods. Studies classified as case reports, clinical trials, non-human studies, conference abstracts, editorials, reviews, books, posters, commentaries; and studies that examined only seasonal effects were excluded. Effect estimates were extracted from published literature. A random effects meta-analysis was performed to pool the relative risks (RRs) of dengue infection per 1 °C increase in temperature, and further subgroup analyses were also conducted. The quality and strength of evidence were evaluated following the Navigation Guide systematic review methodology framework. The review protocol has been registered in the International Prospective Register of Systematic Reviews (PROSPERO).

FINDINGS

The study selection process yielded 6367 studies. A total of 106 studies covering more than four million dengue cases fulfilled the inclusion criteria; of these, 54 studies were eligible for meta-analysis. The overall pooled estimate showed a 13% increase in risk of dengue infection (RR = 1.13; 95% confidence interval (CI): 1.11-1.16, I² = 98.0%) for each 1 °C increase in high temperatures. Subgroup analyses by climate zones suggested greater effects of temperature in tropical monsoon climate zone (RR = 1.29, 95% CI: 1.11-1.51) and humid subtropical climate zone (RR = 1.20, 95% CI: 1.15-1.25). Heatwave events showed association with an increased risk of dengue infection (RR = 1.08; 95% CI: 0.95-1.23, I² = 88.9%), despite a wide confidence interval. The overall strength of evidence was found to be "sufficient" for high temperatures but "limited" for heatwaves. Our results showed that high temperatures increased the risk of dengue infection, albeit with varying risks across climate zones and different levels of national income.

INTERPRETATION

High temperatures increased the relative risk of dengue infection. Future studies on the association between temperature and dengue infection should consider local and regional climate, socio-demographic and environmental characteristics to explore vulnerability at local and regional levels for tailored prevention.

FUNDING

Australian Research Council Discovery Program.

Seroepidemiology of Strongyloides spp. Infection in Balimo, Western Province, Papua New Guinea

Strongyloidiasis in Papua New Guinea (PNG) is poorly understood. There have been limited surveys describing the levels of endemicity in some regions of PNG, but in the Western Province, its occurrence and level of burden are unknown. This study aimed to determine the seroepidemiology of Strongyloides spp. seropositivity within a community located in the Balimo region of the Western Province. Plasma samples were collected from 120 adult participants and were subjected to anti-IgG Strongyloides spp. serological testing. Logistical regression analyses were performed to identify relationships between strongyloidiasis and attributes of sociodemography. In this cross-sectional cohort study, 22.5% (27/120; 95% CI: 15.9-30.8%) of participants were seropositive for strongyloidiasis. Participants with higher body mass indices were less likely to be seropositive for Strongyloides spp. infection (odds ratio [OR] = 0.85, P value = 0.008), and in the multivariable analysis, increasing units of age (adjusted OR [aOR] = 0.93, P value = 0.048) and participants ≤ 40 years old were associated with a decreased likelihood of Strongyloides spp. seropositivity (aOR = 0.07, P value = 0.034). The results from this study indicate that the occurrence of strongyloidiasis is high in the Western Province, PNG, and age is a determining factor of seroreactivity. This study provides evidence of endemic strongyloidiasis in this community and raises questions as to the impact of this neglected disease and other intestinal parasites on disease burden and comorbidities.

A systematic review and meta-analysis of human and zoonotic dog soil-transmitted helminth infections in Australian Indigenous communities

Soil-transmitted helminths (STH) infect 1.5 billion people and countless animals worldwide. In Australian Indigenous communities, STH infections have largely remained endemic despite control efforts, suggesting reservoirs of infection may exist. Dogs fulfil various important cultural, social and occupational roles in Australian Indigenous communities and are populous in these settings. Dogs may also harbour zoonotic STHs capable of producing morbidity and mortality in dogs and humans. This review provides an overview of human and zoonotic STH infections, identifies the Australian Indigenous locations affected and the parasite species and hosts involved. The meta-analysis provides estimates of individual study and pooled true prevalence of STH infections in Australian Indigenous communities and identifies knowledge gaps for further research on zoonotic or anthroponotic potential. A systematic literature search identified 45 eligible studies documenting the presence of Strongyloides stercoralis, Trichuris trichiura, Ancylostoma caninum, Ancylostoma duodenale, Ancylostoma ceylanicum, undifferentiated hookworm, and Ascaris lumbricoides. Of these studies, 26 were also eligible for inclusion in meta-analysis to establish true prevalence in the light of imperfect diagnostic test sensitivity and specificity by Rogan-Gladen and Bayesian methods. These studies revealed pooled true prevalence estimates of 18.9% (95% CI 15.8–22.1) for human and canine S. stercoralis infections and 77.3% (95% CI 63.7–91.0) for canine A. caninum infections indicating continued endemicity, but considerably more heterogenous pooled estimates for canine A. ceylanicum infections, and A. duodenale, undifferentiated hookworm and T. trichiura in humans. This review suggests that the prevalence of STHs in Australian Indigenous communities has likely been underestimated, principally based on imperfect diagnostic tests. Potential misclassification of hookworm species in humans and dogs due to outdated methodology, also obscures this picture. High-quality contemporary studies are required to establish current true prevalence of parasite species in all relevant hosts to guide future policy development and control decisions under a culturally sound One Health framework.

Soil-transmitted helminths include hookworms, threadworms, whipworms and roundworms. These worms may infect different hosts including humans and dogs, and some species are zoonotic, meaning that they are able to transmit between animals and humans. In many Australian Indigenous communities, people remain infected with these worms at high rates compared to other parts of the country despite various control strategies. Resource and health literacy inequalities are primary drivers for these differences. However, the potential for dogs to act as reservoirs for zoonotic worm infections in humans must also be considered. For this reason, it’s important to create a clear picture of the level of infection by location and host. Given that tests used to establish prevalence can produce false positive or negative results, we performed a meta-analysis allowing comparison of true prevalence estimates by location and host, regardless of the test used. This review suggests that threadworm and dog hookworm remain endemic in Australian Indigenous communities, though a gap exists to accurately inform the prevalence of the other worms. It also highlights the need for One Health strategies in research, policy and control where humans, all animal hosts and the environment are considered in a culturally relevant way.

Neglected Tropical Diseases in Lebanon

INTRODUCTION

Neglected tropical diseases (NTDs) are highly endemic and distributed within the Middle East and North Africa (MENA) region, affecting an estimated 65 million people. Lebanon suffers from several NTDs as they are either endemic in the country or imported via expats residing in endemic regions, refugees, and foreign labor force. The Syrian crisis and the displacement of refugees to Lebanon have made the country the largest host of refugees per capita right after the Syrian crisis in 2011, peaking in the year of 2013. Additionally, foreign labor in Lebanon come from different countries in Africa and Asia that are endemic with certain NTDs. The Lebanese diaspora is approximately twice the number of those residing in the country and is distributed throughout the continents carrying the risk of importing new NTDs.

MATERIALS AND METHODS

A descriptive study about the prevalence of NTDs in Lebanon, their distribution, and factors contributing to spread was performed. The Lebanese Ministry of Public Health (LMPH) database regarding reportable transmissible diseases was reviewed for reportable NTDs between 2002 and 2020 in relation to age, gender, prevalence, and geographical distribution. The medical literature was searched using several engines looking for all reports about NTDs in Lebanon, those relevant to regions hosting Lebanese diaspora, and countries where the refugees and migrant workers came from.

RESULTS

Only leishmaniasis, leprosy, echinococcosis, schistosomiasis, and rabies are mandatorily reportable NTDs by the LMPH. Additionally, case reports about fasciolosis, ascaridiosis, and Dengue were reported from Lebanon. The presence of the Syrian refugees in the country affected the prevalence of leishmaniasis and rabies. The most prevalent NTD in Lebanon is cutaneous leishmaniasis. The Lebanese diaspora reside mainly in South America, Africa, and in some Arab states known to be endemic with certain NTDs.

CONCLUSION

Little information is known about NTDs in Lebanon. The country is at an increased risk of experiencing several new NTDs due to refugee influx, foreign labor, economic crisis, and ever-growing number of Lebanese seeking work opportunities abroad. More information is needed to assess the true burden of NTDs in Lebanon and the future steps to contain and mitigate their effects.

Balantidium coli; Rare and Accidental Finding in the Urine of Pregnant Woman: Case Report

Background

Balantidium coli is a ciliated protozoan parasite, which causes intestinal and extraintestinal infections in humans. It is transmitted feco-orally by ingesting infective cysts with food and water. Urinary balantidiasis may occur through contamination (direct spread from the anal area), secondarily to rectovaginal fistula and following immune suppression. Data about cases of urinary balantidiasis are rare in the world. Currently, there are no documented reports of urinary balantidiasis in Ethiopia. As our understanding, there are only eleven documented reports of urinary balantidiasis globally. However, cases of urinary balantidiasis among pregnant women have not been documented yet. The aim of this report is to alarm health professionals for considering the occurrence of such rare cases and conduct diagnosis.

Case Presentation

A 24-year old pregnant woman was admitted due to severe preeclampsia and preterm delivery at Debre Tabor Comprehensive Specialized Hospital, gynecology ward. Her urine was presented to inpatient laboratory for routine urinalysis. We detected unusual and ciliated parasite from her urine sediment characterized by its active and rotary motility through its cilia and possessing macro- and micro-nuclei, several food vacuoles and ingested red blood cells inside the cytoplasm. Hematuria, many white blood cells and epithelial cells were also detected from the urine sediment, which suggests genito-urinary tract infection due to this parasite. This rare parasite finding was confirmed to be B. coli.

Conclusion

The route of transmission and extraintestinal existence from this woman’s urine was unclear. It might be due to feco-oral transmission and spread to the genitourinary tract through direct anal contact. Moreover, it might be associated with immune suppression as she is pregnant woman.

Community perceptions and acceptability of mass drug administration for the control of neglected tropical diseases in Asia-Pacific countries: A systematic scoping review of qualitative research

Background

Preventative chemotherapy and mass drug administration have been identified as effective strategies for the prevention, treatment, control and elimination of several NTDs in the Asia-Pacific region. Qualitative research can provide in-depth insight into the social dynamics and processes underlying effective implementation of and adherence to mass drug administration programs. This scoping review examines published qualitative literature to examine factors influencing community perceptions and acceptability of mass drug administration approaches to control NTDs in the Asia-Pacific region.

Methodology

Twenty-four peer reviewed published papers reporting qualitative data from community members and stakeholders engaged in the implementation of mass drug administration programs were identified as eligible for inclusion.

Findings

This systematic scoping review presents available data from studies focussing on lymphatic filariasis, soil-transmitted helminths and scabies in eight national settings (India, Indonesia, Philippines, Bangladesh, Laos, American Samoa, Papua New Guinea, Fiji). The review highlights the profoundly social nature of individual, interpersonal and institutional influences on community perceptions of willingness to participate in mass drug administration programs for control of neglected tropical diseases (NTD). Future NTD research and control efforts would benefit from a stronger qualitative social science lens to mass drug administration implementation, a commitment to understanding and addressing the social and structural determinants of NTDs and NTD control in complex settings, and efforts to engage local communities as equal partners and experts in the co-design of mass drug administration and other efforts to prevent, treat, control and eliminate NTDs.

Conclusion

For many countries in the Asia-Pacific region, the “low hanging fruit has been picked” in terms of where mass drug administration has worked and transmission has been stopped. The settings that remain–such as remote areas of Fiji and Papua New Guinea, or large, highly populated, multi-cultural urban settings in India and Indonesia–present huge challenges going forward.

Qualitative research can provide in-depth insight into the social dynamics and processes underlying effective implementation of and adherence to mass drug administration programs. This scoping review examines published qualitative literature to examine factors influencing community perceptions and acceptability of mass drug administration approaches to control neglected tropical diseases (NTDs) in the Asia-Pacific region. Our analyses highlight the profoundly social nature of individual, interpersonal and institutional influences on community perceptions of willingness to participate in mass drug administration programs for control of NTDs. For many countries in the Asia-Pacific region, the “low hanging fruit has been picked” in terms of where mass drug administration has worked and transmission has been stopped. The settings that remain–e.g. remote areas of Fiji and Papua New Guinea, or large, highly populated, multi-cultural urban settings in India and Indonesia–present huge challenges going forward. Future NTD research and control efforts would benefit from a stronger qualitative social science lens to mass drug administration implementation, a commitment to understanding the socio-structural determinants of NTDs and NTD control in complex settings, and engaging local communities as equal partners and experts in the co-design of mass drug administration and other efforts to prevent, treat, control and eliminate NTDs.

The burden of opisthorchiasis and leptospirosis in Thailand: A nationwide syndemic analysis

Opisthorchiasis, caused by the foodborne trematode parasite Opisthorchis viverrini, is co-endemic with leptospirosis in the Greater Mekong Subregion. Socio-economic determinants, occupational risk factors, and reservoir hosts interact with the diseases in the threat to human health, but the situation has not been explored. We, therefore, studied the interaction between the diseases and their associated risks using a syndemic approach with nationwide data for Thailand. Methods included Bayesian mapping, principal component analysis (PCA), and nested correlation analysis to analyze the data for 2009 and 2014. Bayesian mapping demonstrates that opisthorchiasis acts in a synergistic manner to massively alter the risk of leptospirosis at the provincial level, particularly in areas of opisthorchiasis endemicity in Northeast Thailand. Socio-economic and occupational factors significantly influence the disease syndemic with moderate effect sizes of -0.4 and 0.5, respectively (P<0.001). These effects are most remarkable in the northeastern region, which has not only the highest poverty level but also the highest proportion of occupational risk (P<0.001). Cats and dogs play crucial roles in maintaining the syndemic (r-value 7 and 6 with P<0.001). The study shows that opisthorchiasis and leptospirosis become syndemic, especially in North-East, Thailand. Socio-economic and occupational variables are positively syndemic as they are representative of neglected tropical diseases. The role of reservoir hosts underlines the value of an interdisciplinary approach, such as One Health for Sustainability Disease Control.

The Global Trends and Regional Differences in Incidence of Dengue Infection from 1990 to 2019: An Analysis from the Global Burden of Disease Study 2019

Introduction

Dengue, as a neglected tropical disease, brings a heavy socioeconomic burden. To provide tailored global prevention strategies, we analyzed the global trends and regional differences in incidence of dengue infection from 1990 to 2019.

Methods

We obtained data on annual dengue episodes and incidence rates, which reflected the epidemic status of dengue infection from the 2019 Global Burden of Disease (GBD) Study. The changes in dengue episodes and estimated annual percentage changes (EAPCs) of the age-standardized incidence rate (ASR) were calculated to quantify the temporal trends of dengue infection.

Results

Globally, dengue ASR increased by 1.70% (95% CI 1.62%–1.78%) per year from 1990 to 2011; subsequently, it decreased by 0.41% (95% CI 0.20%–0.62%) per year from 2011 to 2019. However, the global number of dengue episodes increased steadily by 85.47% from 30.67 million in 1990 to 56.88 million in 2019. Against the global trend of decreasing ASR from 2011 to 2019, an increasing trend was reported in Oceania (EAPC 11.01, 95% CI 8.79–13.27), East Asia (EAPC 4.84, 95% CI 2.70–7.03) and Southeast Asia (EAPC 0.38, 95% CI 0.13–0.62). For socio-demographic index (SDI) regions, ASR continued to have an increasing trend in the middle (EAPC 0.26, 95% CI 0.07–0.45) and high-middle (EAPC 1.70, 95% CI 0.98–2.42) SDI regions from 2011 to 2019. In contrast to the global peak age of dengue incidence rate (10 to 25 years), the dengue incidence rate of older people (> 65 years) was higher than in other age groups in low and low-middle SDI regions. Additionally, the proportions of dengue episodes in the > 70-year-old age group increased in 2019 (using the baseline in 1990 or 2011) in most GBD regions.

Conclusions

Global dengue episodes have increased tremendously in 3 decades. Although global dengue ASR decreased in the last decade, it is still increasing in hyperendemic regions including Oceania, East Asia and Southeast Asia, and also in the middle and high-middle SDI regions. More attention should be paid to the elderly because of the higher dengue incidence rate among them in low and low-middle SDI regions and the increased proportions of dengue episodes among the elderly in most GBD regions. Therefore, more efforts should be undertaken to develop targeted prevention strategies for crucial regions and older populations.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40121-021-00470-2.

Strongyloidiasis: the most neglected tropical disease in Ethiopia

Background

Strongyloidiasis is the most neglected of the neglected tropical diseases (NTDs). The aim of this commentary is to describe the possible reasons why strongyloidiasis is so overlooked in Ethiopia, and shed light on better ways of control and elimination of the disease.

Main body

This commentary highlights three points why strongyloidiasis is the most neglected of the NTDs in Ethiopia. Firstly, lack of clear category within the NTDs resulted in omission of the disease from reports, intervention programs, and preventive chemotherapy guidelines. Secondly, magnitude of the disease is underestimated due to paucity of studies and low sensitivity of diagnostic methods coupled with asymptomatic nature of most of the infections. Finally, ivermectin (the drug of choice for treatment of strongyloidiasis) is not in use for control of the other soil-transmitted helminthiasis, nor is there ivermectin mass drug administration for control of strongyloidiasis. This might have created gap in control and elimination of the disease in Ethiopia and possibly elsewhere.

Conclusion

Strongyloidiasis appears to be the most neglected of the NTDs mainly due to nature of the infection, low sensitivity of the routine diagnostic tools and it’s exclusion from strategic plans and intervention programs. Moreover, studies on strongyloidiasis should use sensitive diagnostic tools. Strongyloidiasis control and elimination programs should be based on reliable evidence of epidemiology of the disease in Ethiopia.

Graphic Abstract

Prevalence of Balantidium coli (Malmsten, 1857) infection in swine reared in South Italy: A widespread neglected zoonosis

Background and Aim:

Balantidiasis, caused by Balantidium coli (syn. Neobalantidium coli or B. coli), represents a neglected parasitic infection of zoonotic significance affecting a variety of hosts, including domestic pigs that are the main reservoir. B. coli has a direct life cycle with a fecal-oral route transmission that occurs mainly by the ingestion of food and water contaminated with cysts. The ingestion of meat contaminated during inappropriate slaughtering processes may represent a new potential route of transmission. Only a few studies have investigated the prevalence of B. coli in domestic pigs in Italy, despite its high prevalence and zoonotic significance. This study aimed to improve the knowledge on B. coli prevalence in domestic swine reared both in intensive and “en plein air” breeding systems in the south of Italy.

Materials and Methods:

The infection rate of B. coli in pigs bred in 15 different pig farms and regularly slaughtered in South Italy, in the Calabria region, was investigated. From 2017 to 2019, 177 terminal parts of the rectums of pigs, of which 91 commercial hybrids and 86 autochthonous (Nero Calabrese), reared, respectively, in intensive and “en plein air” breeding system, were tested for parasite detection. After the slaughtering, the terminal part of the rectum was sampled and transported to the laboratories and immediately processed. For the detection of trophozoites, fresh smears of feces were examined at light microscopy. Moreover, flotation was performed using a sodium chloride solution, then smears of feces were dispersed on microscope slides and examined at light microscopy. The observed parasites were identified at the species level using morphological characteristics.

Results:

B. coli was detected in a total of 83 (i.e., 46.89%) pigs, with a significantly higher prevalence (p<0.0001) found in commercial hybrid (i.e., 59/91-64.84%) pigs rather than in autochthonous ones (i.e., 24/86-27.91%). It follows that the infection was more common in pigs reared in the intensive breeding system than in “en plein air” ones (p<0.0001). The infection prevalence was higher in males than in females and lower in elder animals than in younger ones (p=0.012 and p<0.0001, respectively).

Conclusion:

The breeding system is likely the main discriminant for the parasite spread as well as the hygienic condition of the farms. Good manufacturing and hygiene practices along the food production chain are crucial in preventing human balantidiasis transmission by meat consumption. The high B. coli prevalence, the wide spectrum of host species, and its zoonotic significance push toward a greater public interest.

Applications of Systems Science to Understand and Manage Multiple Influences within Children's Environmental Health in Least Developed Countries: A Causal Loop Diagram Approach

Least developed countries (LDCs) are home to over a billion people throughout Africa, Asia-Pacific, and the Caribbean. The people who live in LDCs represent just 13% of the global population but 40% of its growth rate. Characterised by low incomes and low education levels, high proportions of the population practising subsistence living, inadequate infrastructure, and lack of economic diversity and resilience, LDCs face serious health, environmental, social, and economic challenges. Many communities in LDCs have very limited access to adequate sanitation, safe water, and clean cooking fuel. LDCs are environmentally vulnerable; facing depletion of natural resources, the effects of unsustainable urbanization, and the impacts of climate change, leaving them unable to safeguard their children’s lifetime health and wellbeing. This paper reviews and describes the complexity of the causal relationships between children’s health and its environmental, social, and economic influences in LDCs using a causal loop diagram (CLD). The results identify some critical feedbacks between poverty, family size, population growth, children’s and adults’ health, inadequate water, sanitation and hygiene (WASH), air pollution, and education levels in LDCs and suggest leverage points for potential interventions. A CLD can also be a starting point for quantitative systems science approaches in the field, which can predict and compare the effects of interventions.

An Approach to a Patient with Tropical Infection in the Intensive Care Unit

How to cite this article: Karnad DR, Amin P. An Approach to a Patient with Tropical Infection in the Intensive Care Unit. Indian J Crit Care Med 2021;25(Suppl 2):S118–S121.

Histopathological and biochemical studies on immunocompetent and immunocompromised Hymenolepis nana infected mice treated with Commiphora molmol (Mirazid)

Hymenolepiasis is a common parasitic infection of children and considered an opportunistic disease with a life-threatening effect among immunocompromised patients through cysticercoid dissemination. Mirazid (Commiphora molmol) is new phytotherapy for hymenolepiasis. So, the present study aimed to evaluate the effects of Mirazid treatment comparing to Praziquantel (PZQ) (standard treatment) among immunocompetent and immunocompromised infected albino mice through biochemical and histopathological parameters. A total of 60 clean male albino mice (immunocompetent group) were divided into equal five groups which were infected and treated with Mirazid beside PZQ. Another 72 infected immunocompromised animals were divided into equal six groups and were also treated with Mirazid and PZQ. Liver and kidney functions were estimated as well as histopathological examination of intestine and liver. Levels of AST in the serum of infected mice treated with Mirazid or PZQ recorded a highly significant increase compared to the normal control group. The percentage of increase was 83.30% and 36.60% respectively. While the infected group recorded a non-significant decrease in AST level and the percentage of decrease was - 7.4%. Immunocompetent groups showed a positive significant correlation with the control Mirazid or control PZQ groups recorded an increase in liver function enzymes (AST, Bilirubin, and GGT) (P < 0.001) comparing to the normal control group. In conclusion, Mirazid showed higher cure rates than PZQ, 95.45%, and 74.54% on the 15th and the 21st days, it reached 100% respectively associated with good improvement of histopathological changes in intestine and liver.

A systematic review and meta-analysis of Hymenolepis nana in human and rodent hosts in Iran: A remaining public health concern

Hymenolepis nana, as a neglected zoonotic helminth, naturally occurs in both humans and rodents. Herein, a systematic review and meta-analysis was carried out to estimate pooled prevalence of H. nana infection among human and rodent hosts for the first time in Iran. PubMed, Web of Science, Scopus, and Embase databases (English articles) and SID and Magiran databases (Persian articles) were systematically searched for relevant studies published from inception till May 24, 2020. Chi² and I² index were used to assess the heterogeneity of the included studies. Publication bias was assessed using Egger's intercept and visual inspection of the funnel plot. Pooled prevalence was estimated using random-effects model with 95 % confidence interval (CI) and depicted as a forest plot. STATA software was used for analysis. The overall pooled prevalence estimate of H. nana in humans included 1.2 % (95 % CI = 1.0-1.4%). Subgroup analysis revealed 2.2 % (95 % CI = 1.8-2.6%) and 0.5 % (95 % CI = 0.3 to 0.8 %) of H. nana infection among school children and food handlers, respectively. In terms of rodent hosts, the overall pooled prevalence of H. nana infection included 13 % (95 % CI = 9.3-16.6%). Subgroup analysis revealed the highest rate of the infection was in Rattus spp. (19.6 %; 95 % CI = 10.6-28.6%), a genus with synanthropic behavior. It seems, despite the advancement in sanitation infrastructure and hygiene status, the H. nana infection compares to other helminthic diseases remains a challenging public health problem in Iran.

Innate immune responses to malaria-infected erythrocytes in pregnant women: Effects of gravidity, malaria infection, and geographic location

BACKGROUND

Malaria in pregnancy causes maternal, fetal and neonatal morbidity and mortality, and maternal innate immune responses are implicated in pathogenesis of these complications. The effects of malaria exposure and obstetric and demographic factors on the early maternal immune response are poorly understood.

METHODS

Peripheral blood mononuclear cell responses to Plasmodium falciparum-infected erythrocytes and phytohemagglutinin were compared between pregnant women from Papua New Guinea (malaria-exposed) with and without current malaria infection and from Australia (unexposed). Elicited levels of inflammatory cytokines at 48 h and 24 h (interferon γ, IFN-γ only) and the cellular sources of IFN-γ were analysed.

RESULTS

Among Papua New Guinean women, microscopic malaria at enrolment did not alter peripheral blood mononuclear cell responses. Compared to samples from Australia, cells from Papua New Guinean women secreted more inflammatory cytokines tumor necrosis factor-α, interleukin 1β, interleukin 6 and IFN-γ; p<0.001 for all assays, and more natural killer cells produced IFN-γ in response to infected erythrocytes and phytohemagglutinin. In both populations, cytokine responses were not affected by gravidity, except that in the Papua New Guinean cohort multigravid women had higher IFN-γ secretion at 24 h (p = 0.029) and an increased proportion of IFN-γ+ Vδ2 γδ T cells (p = 0.003). Cytokine levels elicited by a pregnancy malaria-specific CSA binding parasite line, CS2, were broadly similar to those elicited by CD36-binding line P6A1.

CONCLUSIONS

Geographic location and, to some extent, gravidity influence maternal innate immunity to malaria.

Admixture and natural selection shaped genomes of an Austronesian-speaking population in the Solomon Islands

People in the Solomon Islands today are considered to have derived from Asian- and Papuan-related ancestors. Papuan-related ancestors colonized Near Oceania about 47,000 years ago, and Asian-related ancestors were Austronesian (AN)-speaking population, called Lapita, who migrated from Southeast Asia about 3,500 years ago. These two ancestral populations admixed in Near Oceania before the expansion of Lapita people into Remote Oceania. To understand the impact of the admixture on the adaptation of AN-speaking Melanesians in Near Oceania, we performed the genome-wide single nucleotide polymorphism (SNP) analysis of 21 individuals from Munda, the main town of the New Georgia Islands in the western Solomon Islands. Population samples from Munda were genetically similar to other Solomon Island population samples. The analysis of genetic contribution from the two different ancestries to the Munda genome revealed significantly higher proportions of Asian- and Papuan-related ancestries in the region containing the annexin A1 (ANXA1) gene (Asian component > 82.6%) and in the human leukocyte antigen (HLA) class II region (Papuan component > 85.4%), respectively. These regions were suspected to have undergone natural selection since the time of admixture. Our results suggest that admixture had affected adaptation of AN-speaking Melanesians in the Solomon Islands.

Balantidium coli in domestic animals: An emerging protozoan pathogen of zoonotic significance

Balantidium coli (B. coli) is an emerging ciliated protozoan parasite of zoonotic importance which causes a disease balantidiasis in a variety of host species including pigs, camels, ruminants, equines and even human. This disease has a cosmopolitan distribution with high prevalence rates in tropical and sub-tropical areas of the world due to favorable geo-climatic conditions for the development and survival of the parasite in these regions. Main reservoir hosts for this pathogen are pigs and animals; acquire infection mainly by the ingestion of the food or water contaminated with the porcine feces. The infected animal manifests clinical signs of anorexia, dehydration, profuse watery diarrhea and retarded growth. Wet mount slide prepared from intestinal scrapings and fecal material is used for the identification of trophozoites and cysts stages of this parasite. PCR can also be used to confirm the parasite. Secnidazole, oxytetracycline and metronidazole have varying efficacy against B. coli infection in various domestic animal species. There is no comprehensive literature available on the occurrence and distribution of the infection at international level. Therefore, the published data between 1989 and 2019 regarding this disease is critically analyzed to provide a detailed overview on this pathogen with special emphasis on geographical distribution of B. coli in domestic animals and different therapeutic agents used to treat this infection. This review will pinpoint the endemic regions which may be a source of potential disease outbreaks and will also help in application of more effectual control strategies against balantidiasis.

Contamination of milk and dairy products by Brucella species: A global systematic review and meta-analysis

Brucellosis is known as an influential zoonosis in different regions worldwide, with significant effects on the reproductive performance of livestock. Considering the high incidence of brucellosis in dairy products and further negative impacts on food safety, the present study was aimed to systematically investigate prevalence worldwide among published data regarding the identification of Brucella spp. in dairy products. In this regard, some databases, i.e., Scopus, PubMed, Embase, and Web of Science have been searched to retrieve all related articles regarding the incidence of Brucella contaminations in dairy products from 1 January 1983 to 1 April 2019. The prevalence of Brucella spp. in unpasteurized dairy products based on countries, WHO regions, and dairy product subgroups were evaluated and statistically compared. Based on the findings, the prevalence of Brucella spp. in dairy products increased while the GDP (C = 0.17, P-value < 0.001) and HDI (C = 0.19, P-value < 0.001) ranking decreased. Also, the highest prevalence of Brucella contamination in dairy products was noted in buffalo (25.91%) and goat (17.90%), respectively. The lowest and highest prevalence of Brucella spp. were observed in the Western Pacific (15.32%) and the Southeast Asia region (25.55%), respectively. Also, the rank order of WHO regions based on odds ratio (OR) was Southeast Asia region (2.84) > Eastern Mediterranean (2.41) > Region of America (1.65) > European Region (1.54) > Africa region (1.46) > Western Pacific (reference). The results of this study showed that decreasing poverty and an increase in the level of education in societies could reduce the prevalence of Brucella spp. in dairy products. The outcome of the current investigation can be used for the implementation of sustainable intervention and prevention strategies in affected regions.

Health Challenges of the Pacific Region: Insights From History, Geography, Social Determinants, Genetics, and the Microbiome

The Pacific region, also referred to as Oceania, is a geographically widespread region populated by people of diverse cultures and ethnicities. Indigenous people in the region (Melanesians, Polynesians, Micronesians, Papuans, and Indigenous Australians) are over-represented on national, regional, and global scales for the burden of infectious and non-communicable diseases. Although social and environmental factors such as poverty, education, and access to health-care are assumed to be major drivers of this disease burden, there is also developing evidence that genetic and microbiotic factors should also be considered. To date, studies investigating genetic and/or microbiotic links with vulnerabilities to infectious and non-communicable diseases have mostly focused on populations in Europe, Asia, and USA, with uncertain associations for other populations such as indigenous communities in Oceania. Recent developments in personalized medicine have shown that identifying ethnicity-linked genetic vulnerabilities can be important for medical management. Although our understanding of the impacts of the gut microbiome on health is still in the early stages, it is likely that equivalent vulnerabilities will also be identified through the interaction between gut microbiome composition and function with pathogens and the host immune system. As rapid economic, dietary, and cultural changes occur throughout Oceania it becomes increasingly important that further research is conducted within indigenous populations to address the double burden of high rates of infectious diseases and rapidly rising non-communicable diseases so that comprehensive development goals can be planned. In this article, we review the current knowledge on the impact of nutrition, genetics, and the gut microbiome on infectious diseases in indigenous people of the Pacific region.

Leptospirosis in French Polynesia: 11 years of surveillance data, 2007-2017

Leptospirosis is a worldwide zoonosis with higher incidence in tropical areas and is a neglected disease in the Pacific region. French Polynesia (FP) is a French overseas territory located in the South Pacific. Data on the epidemiology in FP are scarce. In this study, we describe our understanding of leptospirosis epidemiology in FP and discuss the prospects concerning this disease and its surveillance to better address preventive actions. We report 11 years of surveillance data between 1 January 2007 and 31 December 2017. Over the study period, 1356 confirmed and probable leptospirosis cases were reported. The mean annual incidence rate was 46.0 (95% confidence interval, 43.6-48.5) cases per 100 000 inhabitants. We registered 864 (63.7%) hospitalizations; of these, at least 270 (19.9%) were in the intensive care unit, and 24 patients (1.8%) died. Even if the incidence of leptospirosis is lower in FP compared to most of other Pacific countries and territories, our data confirm that the disease is highly endemic in FP. Despite all the preventive measures taken, leptospirosis remains a major public health concern in FP, thus highlighting the need to maintain intensive leptospirosis surveillance, medical staff training and provision of information to the general population.

Observations of Pediatric Disease Prevalence from Pacific Partnership 2015

Pacific Partnership is an ongoing yearly humanitarian assistance mission to Pacific Rim countries. Although many case reports and surgical successes have been documented, few data have been published specifically about the primary care mission. This article analyzes outpatient pediatric data collected during Pacific Partnership 2015. Eleven different providers documented care delivered to children from birth through age 18 yr, inclusive. Personally de-identified data were entered into spreadsheets, sorted according to country visited, and analyzed with IBM SPSS software looking for disease frequency. One thousand eighty-seven pediatric patients were seen across Fiji, Papua New Guinea (PNG), and the Philippines (PI). Asthma was the first, second, and third most prevalent diagnosis in PNG, Fiji, and PI, with a relative proportion of the total patients seen at 5.4%, 7.2%, and 5%, respectively. In PI, 123 cases of upper respiratory infection were seen, more than four times the next most common diagnosis of normal exam. Thirty-six patients with scabies were seen in Fiji (number 1), with abdominal pain at number 3 (26 cases, 6.5%). Surprisingly, helminths were rarely seen, comprising the sixteenth and fourteenth most common diagnoses in Fiji and PI and only two cases in PNG. Future Pacific Partnership missions can plan medication stock, personnel assignment, equipment needs, and educational literature based on these data.

Leprosy in French Polynesia

Leprosy is a neglected endemic infectious disease in the Pacific region. In French Polynesia (FP), leprosy is no longer a public health problem at the national level, defined by the World Health Organization as a prevalence rate below 1 case per 10,000 population. However, even if its incidence has dramatically declined in FP in the last decades, leprosy is still endemic at a low level. Here we present a case of leprosy in a 34-year-old man from FP diagnosed in 2018. Clinical and microbiologic examinations, including fluorescence in-situ hybridization, led to the diagnosis of a multibacillary leprosy, and multidrug therapy was initiated. There is a need to maintain leprosy surveillance and trained medical staff for the detection and treatment of new cases.

The First Case of Diarrhoea in Tibetan Sheep, Ovis aries, Caused by Balantidium coli in the Qinghai Tibetan Plateau Area, China

This study was carried out to determine the pathogen-causing diarrhoea in sheep Ovis aries in the Qinghai Tibetan Plateau Area, China. A trophozoite was identified as species of ciliate alveolates infecting the sheep based on morphological characteristics examined by microscope. It was mostly spherical, colourless and transparent, with many vesicles. Macronucleus and contractile vacuoles could not be distinguished. Size of the trophozoite was 80–180×70–150 μm and its surface was covered with cilia. Molecular analysis based on sequences of 18S rRNA and ITS genes confirmed the ciliate species as Balantidium coli. According to the literature, there have been many epidemiological investigations of B. coli infection in pigs, monkeys and humans. To our knowledge, this was the first report of B. coli infections in sheep in the Qinghai Tibetan Plateau Area of China, or eleswhere around the world. Importantly, the sheep case was rare but raised our concern that B. coli may spread across species and expand its host range.

A systematic review of historical and contemporary evidence of trachoma endemicity in the Pacific Islands

INTRODUCTION

Trachoma is endemic in several Pacific Island countries. The aims of this study were to (a) identify future trachoma mapping needs in the Pacific and (b) to examine whether any temporal trends in trachoma prevalence could be ascertained from the historical literature on trachoma in the Pacific Islands.

METHODS

Human studies of trachoma and eye care in the Pacific Islands were identified from a systematic search of PubMed, EMbase, Scopus and Web of Science databases. A published quality assessment system for disease prevalence studies was modified to assess studies for quality and transparency.

RESULTS

Few general ophthalmic studies in the Pacific mention trachoma. In targeted studies of trachoma, cases have consistently been identified throughout the Pacific since the early twentieth century. The largest number of studies come from Papua New Guinea and Fiji, whereas some countries have no published data on trachoma. The majority of studies identified were published before the Alliance for the Global Elimination of Trachoma 2020 was convened, so lack the standardisation of population-based mapping which has been implemented in the past decade.

CONCLUSIONS

Population-based trachoma prevalence estimates have been recently generated in Papua New Guinea, Solomon Islands, Vanuatu, Kiribati and Fiji. There is insufficient evidence to assess whether there has been temporal change in trachoma prevalence in these countries over the past century. Cases of trachoma have been identified in some countries (for example, Nauru and Samoa) which have no recent population-based mapping data, but may be at risk of trachoma endemcitiy. Deployment of appropriate mapping strategies is warranted to identify whether interventions are required.

BLASTOCYSTIS AND OTHER INTESTINAL PARASITES INFECTIONS IN ELEMENTARY SCHOOL CHILDREN IN DUKUH VILLAGE, KARANGASEM DISTRICT, BALI

Blastocystis spp. is the most common enteric parasitic infection found in several community surveys from developing countries. Blastocystis infections may cause gastrointestinal symptoms, but also cause extraintestinal symptoms such as urticaria and joint pain. Blastocystis infection can also be asymptomatic or a carrier. However, the prevalence of Blastocystis infection in children has not yet been fully investigated in Indonesia, particularly in Bali Province. This study aimed to determine the prevalence of Blastocystis and other intestinal parasites in elementary school children stools in Dukuh village, Karangasem regency. A cross sectional study was conducted in September 2016. A total of 103 school children stools were collected by informed consent and parasites were examined by microscopy with wet mounts method using Lugol’s iodine solution. Thirty-five school children were infected with Blastocystis spp. (35/103, 34%) that consisted of a single infection (29/35, 82.9%) and mix infection with other parasites (6/35, 17.1%). The mix infections were Blastocystis spp. and hookworm infection (1/6, 16.7%), Blastocystis spp. and Entamoeba coli (1/6, 16.7%), Blastocystis spp. and Giardia lamblia (2/6, 33.3%), Blastocystis spp. and Entamoeba histolytica/ Entamoeba dispar (1/6, 16.7%) and Blastocystis spp. and Entamoeba histolytica/ Entamoeba dispar and Giardia lamblia (1/6, 16.7%). The vacuolar forms of Blastocystis were dominantly found, in which was non-infectious form, whereas the infectious form is the cyst form and Blastocystis density was observed less than 5 cells per field of view at 400 magnification in all cases. This study concluded that the high prevalence of Blastocystis infection in elementary school children in Dukuh Village, Karangasem District, Bali that were dominantly single infections and several mix infections with other intestinal parasites. The high prevalence of Blastocystis infection in elementary school children suggested that it needs proper prevention measures for the children in this study area.

The History of Bancroftian Lymphatic Filariasis in Australasia and Oceania: Is There a Threat of Re-Occurrence in Mainland Australia?

Lymphatic filariasis (LF) infects an estimated 120 million people worldwide, with a further 856 million considered at risk of infection and requiring preventative chemotherapy. The majority of LF infections are caused by Wuchereria bancrofti, named in honour of the Australian physician Joseph Bancroft, with the remainder due to Brugia malayi and B. timori. Infection with LF through the bite of an infected mosquito, can lead to the development of the condition known as elephantiasis, where swelling due to oedema leads to loss of function in the affected area and thickening of the skin, 'like an elephant'. LF has previously been endemic in Australia, although currently, no autochthonous cases occur there. Human immigration to Australia from LF-endemic countries, including those close to Australia, and the presence of susceptible mosquitoes that can act as suitable vectors, heighten the possibility of the reintroduction of LF into this country. In this review, we examine the history of LF in Australia and Oceania and weigh up the potential risk of its re-occurrence on mainland Australia.

The impact of national policies on animal disease reporting within selected Pacific Island Countries and Territories (PICTs)

A semi-systematic literature review of national policies was carried out in relation to surveillance and disease reporting in Pacific Island Countries and Territories (PICTs). It also analysed the animal disease reporting structures in Fiji, Papua New Guinea (PNG), Vanuatu and the Solomon Islands. The strengths, weaknesses, opportunities and threats (SWOT) of those reporting structures were examined in relation to how they impacted the detection and management of animal diseases in PICTs. Field missions collected information on animal disease reporting structures and these were discussed in detail with country officials and documented. The findings from the literature review indicated that there is very little policy to support work in surveillance and disease reporting within national government structures of the countries studied. This increases the potential for disease transmission and the introduction of exotic diseases as the efficiency of disease reporting is low. The findings from the SWOT analysis of the reporting structures indicated that there were commonalities across the countries studied, i.e. reporting structures were long with multiple legs that were not functioning properly and this was worsened when positions were vacant in the reporting structure. The hierarchical nature of the reporting structure also reduced reporting efficiency as reports took a longer time to reach decision makers at the top of the structure. High officer turnover and the shortage of veterinarians in the countries studied also affected the efficiency of disease reporting as most in-county officials were inexperienced and could not recognise disease signs and there were no veterinarians to supervise them. Existing reporting structures need to be reviewed to remove duplication and shorten the chain. However, this could override existing command structures and would need to be documented and awareness created with the officers involved. There also needs to be more collaboration with FAO, OIE, academic institutions and national governments to create an environment conducive for the development of policies that support work on surveillance to improve disease reporting in PICTs. The shortage of veterinarians could be addressed by influencing national governments to create better policies to retain veterinarians in the animal health services; this should be supported by creating reasonable work conditions and remuneration packages. This should also be supported with policies to send young graduates to study veterinary science overseas and have a career path for them when they return. Engagement of retired veterinarians from developed countries and re-evaluating the criteria for veterinarian registration could be short-term solutions to address the shortage of veterinarians in PICTs.

Ancylostoma ceylanicum, novel etiological agent for traveler's diarrhea-report of four Japanese patients who returned from Southeast Asia and Papua New Guinea

Background

Countries in the Southeast Asia region have a high prevalence of soil-transmitted helminth, such as roundworm, whipworm, and hookworms [Ancylostoma duodenale, Necator americanus, Ancylostoma ceylanicum]. Recent molecular-based surveys have revealed that A. ceylanicum, a zoonotic hookworm, is likely the second most prevalent hookworm species infecting humans in that part of the world, while others have noted that this infection is an emerging public health risk not only for indigenous people but also for visitors from other countries.

Case presentation

We recently encountered four cases of A. ceylanicum infection in Japanese individuals who returned from Southeast Asia and Papua New Guinea. Case 1 was a 25-year-old male who stayed in a rainforest in Malaysia for 4 weeks, where he developed abdominal pain and diarrhea in the third week. Eleven adult worms (five males, six females) were expelled after treatment with pyrantel pamoate and identified as A. ceylanicum based on morphological characteristics and DNA sequences of the mitochondrial cytochrome c oxidase subunit 1 (cox1) gene. Case 2 was a 26-year-old male who spent 2 years as an overseas cooperation volunteer for agriculture in Papua New Guinea. He did not note any symptoms at that time, though eggs were detected in feces samples at a medical check-up examination after returning. Although collection of adult worms was unsuccessful, DNA analysis of the eggs for cox1 and the ribosomal internal transcribed spacer (ITS)-1 and ITS-2 genes demonstrated that they were A. ceylanicum. Case 3 was a 47-year-old male who spent 1 month in a rural village in Lao People's Democratic Republic and began suffering from watery diarrhea from the third week. A total of nine adult worms (three males, six females) were collected by endoscopic procedures and following treatment with pyrantel pamoate. Morphological examination and molecular analyses of the cox1 gene showed that they were A. ceylanicum. Case 4 was a 27-year-old male who participated in group travel to India for 5 days. Three weeks after returning, he developed abdominal pain and diarrhea. Hookworm eggs were found in feces samples and developed into larvae in culture, which were identified as A. ceylanicum based on molecular analysis of the cox1 gene. Eosinophilia was observed in all of the cases prior to treatment.

Conclusions

A. ceylanicum should be recognized as an important etiologic pathogen of hookworm diseases in travelers to countries in the Southeast Asia and West Pacific Ocean regions.

The Attractiveness of the Gravid Aedes Trap to Dengue Vectors in Fiji

The Gravid Aedes Trap (GAT) is a passive trap that relies on visual and olfactory cues to lure and capture gravid mosquitoes. The GAT was designed as a dengue vector surveillance tool for use in conditions where power sources are not readily available. Experiments were conducted over a 10-d period in Fiji to determine which species of mosquitoes the GAT would collect, how different infusion types affect the attractiveness of the trap, how long each infusion type took to begin attracting mosquitoes, and how long the infusion was attractive to container breeding Aedes mosquitoes. Infusions were created by adding 10 g of organic material to 2 liters of water. Infusions were made using chicken feed pellets, dried mango leaves (Mangifera indica), and dried lawn grasses (primarily Axonopus spp.). The GAT collected four different vectors Aedes aegypti (Linnaeus) (Diptera: Culicidae), Aedes albopictus (Skuse) (Diptera: Culicidae), Aedes polynesiensis Mark (Diptera: Culicidae), and Culex quinquefasciatus Say (Diptera: Culicidae). As observed in previous studies, using some type of organic infusion improved the attractiveness of the trap. Of the three different infusion components tested, chicken feed was most attractive followed by lawn grasses and mango leaves. All infusions performed better than plain water. Chicken feed was found to be most attractive for Ae. aegypti and Ae. albopictus during the first 6 d after placing the traps and for Cx. quinquifasciatus in days 7-9. The mango and grass infusions took longer to attract mosquitoes but were most attractive during days 7-10 for all species.

Island-Wide Surveillance of Gastrointestinal Protozoan Infection on Fiji by Expanding Lymphatic Filariasis Transmission Assessment Surveys as an Access Platform

As part of lymphatic filariasis (LF) transmission assessment surveys (TAS) on Fiji, an island-wide assessment of gastrointestinal protozoan infection was performed by inspection of a concomitant stool sample collection to investigate the distribution of parasitic protozoa. All grade 1 and 2 students of 69 schools on the two main islands were targeted in two phases (one in the Western Division and the other in the Central and Northern Divisions, except Taveuni sub-Division of Northern), where fecal samples of 1,800 students were available for coproscopy using formalin-ether-acetate concentration. The overall prevalence of Giardia infection was 1.6%, having 2.2% in Western and 0.8% in Central/Northern Divisions (P = 0.094). The school-level prevalence of giardiasis ranged from 0% to 15.4%, and hotspot analysis using the Getis-Ord Gi* method detected spatial heterogeneity of giardiasis prevalence in schools around Lautoka (Z-score = 3.36, P value < 0.05), an area affected by Cyclone Kofi in February 2014. Any protozoan infection prevalence was 4.9% in Western and 4.4% in Central/Northern Divisions (P = 0.825). Real-time polymerase chain reaction analysis to confirm the findings from a parasitological examination of a 10% stool archive in 95% ethanol from Western Division revealed an elevated prevalence of giardiasis up to 22.4%, the presence of Entamoeba histolytica, and the absence of Cryptosporidium parvum. Obtaining stool samples alongside LF TAS is a convenient access platform for cosurveillance of gastrointestinal protozoan infection and has pinpointed hitherto unknown hotspots of giardiasis in urban city centers of Fiji. This calls for greater attention to apply tailored water, sanitation and hygiene measures for the control of these parasites.

Pulmonary strongyloidiasis: assessment between manifestation and radiological findings in 16 severe strongyloidiasis cases

Background

Strongyloidiasis is a chronic parasitic infection caused by Strongyloides stercoralis. Severe cases such as, hyperinfection syndrome (HS) and disseminated strongyloidiasis (DS), can involve pulmonary manifestations. These manifestations frequently aid the diagnosis of strongyloidiasis. Here, we present the pulmonary manifestations and radiological findings of severe strongyloidiasis.

Methods

From January 2004 to December 2014, all patients diagnosed with severe strongyloidiasis at the University of the Ryukyus Hospital or affiliated hospitals in Okinawa, Japan, were included in this retrospective study. All diagnoses were confirmed by the microscopic or histopathological identification of larvae. Severe strongyloidiasis was defined by the presence of any of the following: 1) the identification of S. stercoralis from extra gastrointestinal specimens, 2) sepsis, 3) meningitis, 4) acute respiratory failure, or 5) respiratory tract hemorrhage. Patients were assigned to either HS or DS. Medical records were further reviewed to extract related clinical features and radiological findings.

Results

Sixteen severe strongyloidiasis cases were included. Of those, fifteen cases had pulmonary manifestations, eight had acute respiratory distress syndrome (ARDS) (53%), seven had enteric bacterial pneumonia (46%) and five had pulmonary hemorrhage (33%). Acute respiratory failure was a common indicator for pulmonary manifestation (87%). Chest X-ray findings frequently showed diffuse shadows (71%). Additionally, ileum gas was detected for ten of the sixteen cases in the upper abdomen during assessment with chest X-ray. While, chest CT findings frequently showed ground-glass opacity (GGO) in 89% of patients. Interlobular septal thickening was also frequently shown (67%), always accompanying GGO in upper lobes.

Conclusions

In summary, our study described HS/DS cases with pulmonary manifestations including, ARDS, bacterial pneumonia and pulmonary hemorrhage. Chest X-ray findings in HS/DS cases frequently showed diffuse shadows, and the combination of GGO and interlobular septal thickening in chest CT was common in HS/DS, regardless of accompanying pulmonary manifestations. This CT finding suggests alveolar hemorrhage could be used as a potential marker indicating the transition from latent to symptomatic state. Respiratory specimens are especially useful for detecting larvae in cases of HS/DS.

Protocol for the systematic review of the prevention, treatment and public health management of impetigo, scabies and fungal skin infections in resource-limited settings

BACKGROUND

Impetigo, scabies, and fungal skin infections disproportionately affect populations in resource-limited settings. Evidence for standard treatment of skin infections predominantly stem from hospital-based studies in high-income countries. The evidence for treatment in resource-limited settings is less clear, as studies in these populations may lack randomisation and control groups for cultural, ethical or economic reasons. Likewise, a synthesis of the evidence for public health control within endemic populations is also lacking. We propose a systematic review of the evidence for the prevention, treatment and public health management of skin infections in resource-limited settings, to inform the development of guidelines for the standardised and streamlined clinical and public health management of skin infections in endemic populations.

METHODS

The protocol has been designed in line with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocols statement. All trial designs and analytical observational study designs will be eligible for inclusion. A systematic search of the peer-reviewed literature will include PubMed, Excertpa Medica and Global Health. Grey literature databases will also be systematically searched, and clinical trials registries scanned for future relevant studies. The primary outcome of interest will be the clinical cure or decrease in prevalence of impetigo, scabies, crusted scabies, tinea capitis, tinea corporis or tinea unguium. Two independent reviewers will perform eligibility assessment and data extraction using standardised electronic forms. Risk of bias assessment will be undertaken by two independent reviewers according to the Cochrane Risk of Bias tool. Data will be tabulated and narratively synthesised. We expect there will be insufficient data to conduct meta-analysis. The final body of evidence will be reported against the Grades of Recommendation, Assessment, Development and Evaluation grading system.

DISCUSSION

The evidence derived from the systematic review will be used to inform the development of guidelines for the management of skin infections in resource-limited settings. The evidence derived will be intended for use by clinicians, public health practitioners and policy makers in the treatment of skin infections and the development of skin infection control programmes. The review will identify any gaps in the current evidence to provide direction for future research.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42015029453.

Short communication: Epidemiological assessment of Strongyloides stercoralis in Fijian children

As a part of the lymphatic filariasis (LF) transmission assessment survey (TAS)/soil-transmitted helminths (STH) prevalence survey in Western Division of Fiji, a pilot screen for Strongyloides stercoralis (SS) in school children was undertaken using a combination of the Baermann concentration (BC) method and real-time PCR assays.

Using BC, faecal samples collected from 111 children of 7 schools were examined. A single child was positive for larvae of SS and underwent a clinical examination finding an asymptomatic infection. Other members of this child's household were screened with BC, finding none infected. Aliquots of 173 faecal samples preserved in ethanol originating from all schools were examined by real-time PCR, and the prevalence of SS infection was 3.5%.

Our study confirms the existence of SS infection on Fiji and showed that assessing SS prevalence alongside TAS/STH survey is a convenient access platform, allowing introduction of other surveillance techniques such as BC and real-time PCR.

The impact of insecticide-treated cloth targets on the survival of Stegomyia polynesiensis (= Aedes polynesiensis) under laboratory and semi-field conditions in French Polynesia

The impact of deltamethrin-impregnated cloth targets on Stegomyia polynesiensis (= Aedes polynesiensis) (Marks) (Diptera: Culicidae) was assessed under laboratory and semi-field settings in French Polynesia. Stegomyia polynesiensis females were released into small laboratory cages and large field cages containing either a deltamethrin-treated or an untreated navy blue cloth, and mosquito knock-down and mortality were assessed. The 24-h mortality rate in mosquitoes exposed to the insecticide-treated target in small cages was 98.0%. These mosquitoes also demonstrated significantly higher levels of knock-down than those exposed to the untreated target. Mortality in field cages was assessed at 24 and 48 h. The 24-h mortality rate in mosquitoes exposed to the control target was 31.2%, whereas that in those exposed to the deltamethrin-treated target was 54.3%. The 48-h mortality rate was also elevated in mosquitoes exposed to the deltamethrin-treated target, but this result did not differ significantly from that observed in mosquitoes exposed to the control target. The significant suppression of female S. polynesiensis by deltamethrin-treated resting targets in this study indicates that these targets could play a role in the control of an important disease vector in the South Pacific region.

A Case of Ancylostoma ceylanicum Infection Occurring in an Australian Soldier Returned from Solomon Islands

A 26-year-old male member of the Australian Defense Force presented with a history of central abdominal pain of 4 weeks duration and peripheral eosinophilia consistent with eosinophilic enteritis. Acute hookworm disease was diagnosed as the cause. Adult worms recovered from feces after therapy with albendazole were morphologically consistent with Ancylostoma ceylanicum. As the patient had been deployed with the Regional Assistance Mission to Solomon Islands for 6 months prior to this presentation, it is very likely that the A. ceylanicum was acquired in Solomon Islands. Until now, it has been assumed that any Ancylostoma spp. recovered from humans in Solomon Islands is A. duodenale. However, this case demonstrates that human hookworm infection acquired in the Solomon Islands could be caused by A. ceylanicum.

Traumatic Myiasis: A Neglected Disease in a Changing World

Traumatic myiasis, the parasitic infestation by fly larvae in traumatic lesions of the tissues of living vertebrates, is a serious medical condition in humans and a welfare and economic issue in domestic animals. New molecular studies are providing insights into its evolution and epidemiology. Nevertheless, its incidence in humans is generally underreported, particularly in tropical and subtropical regions. Myiasis in domestic animals has been studied more extensively, but continuous management is difficult and expensive. A key concern is the inadvertent introduction and global spread of agents of myiasis into nonendemic areas, facilitated by climate change and global transport. The incursion of the New World screwworm fly (Cochliomyia hominivorax) into Libya is the most notable of many such range shifts and demonstrates the potential risks of these parasites and the costs of removing them once established in a geographic area. Nevertheless, the insect agents of myiasis can be of societal benefit to forensic science and in medicine as an aid to wound treatment (larval therapy).