Identification and control of an isolated, but intense focus of lymphatic filariasis on Satawal Island, Federated States of Micronesia, in 2003.

BACKGROUND: There is very limited data available on the prevalence of Bancroftian filariasis in the Federated States of Micronesia (FSM). Considerable attempts to eliminate the disease had occurred in the Pacific region by the year 2003, and the prevalence in FSM was thought to be sufficiently low that the region was considered non-endemic. However, a survey conducted in 2003 on an isolated atoll of FSM, Satawal Island, challenged that assumption. METHODS: Participants on Satawal Island were recruited and their blood tested for Wuchereria bancrofti antigen by the filariasis immunochromatographic test (ICT) card and circulating microfilaria by Knott's concentration technique. A survey for active cases of lymphoedema, elephantiasis and hydrocoele was performed and mosquitoes were trapped and dissected to detect larvae of W. bancrofti. RESULTS: A total of 104 males and 149 females from early teens to mid-80s were tested. Men had a significantly higher prevalence of infection than women in both the ICT test (53 vs 28%; p < 0.001) and by Knott's concentration results (37 vs 11%; p < 0.001). Microfilaria prevalence was higher in subjects ≤25 than in those >25 years of age. All persons sampled were treated for LF. No cases of elephantiasis or hydrocoele were detected. No Aedes dissected were positive but three of nine culicine mosquitoes were positive for L1-3 larval stages of W. bancrofti by microscopy. In depth interviews were conducted with residents and chiefs. CONCLUSIONS: This survey showed that even in regions thought to be close to elimination, isolated high intensity foci of lymphatic filariasis may occur. These need to be recognized and control measures instituted such as local MDA as in the current study.

Mass poisoning after consumption of a hawksbill turtle, Federated States of Micronesia, 2010.

BACKGROUND: Marine turtles of all species are capable of being toxic. On 17 October 2010, health authorities in the Federated States of Micronesia were notified of the sudden death of three children and the sickening of approximately 20 other people on Murilo Atoll in Chuuk State. The illnesses were suspected to be the result of mass consumption of a hawksbill turtle (Eretmochelys imbricata). An investigation team was assembled to confirm the cause of the outbreak, describe the epidemiology of cases and provide recommendations for control. METHODS: We conducted chart reviews, interviewed key informants, collected samples for laboratory analysis, performed environmental investigations and conducted a cohort study. RESULTS: Four children and two adults died in the outbreak and 95 others were sickened; 84% of those who ate the turtle became ill (n = 101). The relative risk for developing illness after consuming the turtle was 11.1 (95% confidence inteval: 4.8-25.9); there was a dose-dependent relationship between amount of turtle meat consumed and risk of illness. Environmental and epidemiological investigations revealed no alternative explanation for the mass illness. Laboratory testing failed to identify a causative agent. CONCLUSION: We concluded that turtle poisoning (also called chelonitoxism) was the cause of the outbreak on Murilo. The range of illness described in this investigation is consistent with previously reported cases of chelonitoxism. This devastating incident highlights the dangers, particularly to children, of consuming turtle meat. Future incidents are certain to occur unless action is taken to alter turtle-eating behaviour in coastal communities throughout the world.

Assessment of Climate-sensitive Infectious Diseases in the Federated States of Micronesia.

BACKGROUND: The health impacts of climate change are an issue of growing concern in the Pacific region. Prior to 2010, no formal, structured, evidence-based approach had been used to identify the most significant health risks posed by climate change in Pacific island countries. During 2010 and 2011, the World Health Organization supported the Federated States of Micronesia (FSM) in performing a climate change and health vulnerability and adaptation assessment. This paper summarizes the priority climate-sensitive health risks in FSM, with a focus on diarrheal disease, its link with climatic variables and the implications of climate change. METHODS: The vulnerability and adaptation assessment process included a review of the literature, extensive stakeholder consultations, ranking of climate-sensitive health risks, and analysis of the available long-term data on climate and climate-sensitive infectious diseases in FSM, which involved examination of health information data from the four state hospitals in FSM between 2000 and 2010; along with each state's rainfall, temperature and El Niño-Southern Oscillation data. Generalized linear Poisson regression models were used to demonstrate associations between monthly climate variables and cases of climate-sensitive diseases at differing temporal lags. RESULTS: Infectious diseases were among the highest priority climate-sensitive health risks identified in FSM, particularly diarrheal diseases, vector-borne diseases and leptospirosis. Correlation with climate data demonstrated significant associations between monthly maximum temperature and monthly outpatient cases of diarrheal disease in Pohnpei and Kosrae at a lag of one month and 0 to 3 months, respectively; no such associations were observed in Chuuk or Yap. Significant correlations between disease incidence and El Niño-Southern Oscillation cycles were demonstrated in Kosrae state. CONCLUSIONS: Analysis of the available data demonstrated significant associations between climate variables and climate-sensitive infectious diseases. This information should prove useful in implementing health system and community adaptation strategies to avoid the most serious impacts of climate change on health in FSM.

Aedes hensilli as a potential vector of Chikungunya and Zika viruses.

An epidemic of Zika virus (ZIKV) illness that occurred in July 2007 on Yap Island in the Federated States of Micronesia prompted entomological studies to identify both the primary vector(s) involved in transmission and the ecological parameters contributing to the outbreak. Larval and pupal surveys were performed to identify the major containers serving as oviposition habitat for the likely vector(s). Adult mosquitoes were also collected by backpack aspiration, light trap, and gravid traps at select sites around the capital city. The predominant species found on the island was Aedes (Stegomyia) hensilli. No virus isolates were obtained from the adult field material collected, nor did any of the immature mosquitoes that were allowed to emerge to adulthood contain viable virus or nucleic acid. Therefore, laboratory studies of the probable vector, Ae. hensilli, were undertaken to determine the likelihood of this species serving as a vector for Zika virus and other arboviruses. Infection rates of up to 86%, 62%, and 20% and dissemination rates of 23%, 80%, and 17% for Zika, chikungunya, and dengue-2 viruses respectively, were found supporting the possibility that this species served as a vector during the Zika outbreak and that it could play a role in transmitting other medically important arboviruses.

Investigating an outbreak of acute fever in Chuuk, Federated States of Micronesia.

OBJECTIVE: In September 2012, there was an unexpected increase of acute febrile illness (AFI) in Chuuk State of the Federated States of Micronesia. At the same time, dengue outbreaks were occurring in two of the Federated States of Micronesia's other three states. The cause of AFI was suspected to be dengue; however, by the end of October, only one of 39 samples was positive for dengue. The objective of the investigation was to establish the cause of the outbreak. METHODS: A line list was created and data analysed by time, place, person and clinical features. Reported symptoms were compared with the published symptoms of several diagnoses and laboratory testing undertaken. RESULTS: Of the 168 suspected cases, 62% were less than 20 years of age and 60% were male. The clinical features of the cases were not typical for dengue but suggestive of respiratory illness. Nasopharyngeal swabs were subsequently collected and found to be positive for influenza. Public health measures were undertaken and the AFI returned to expected levels. DISCUSSION: Clinical diagnosis of acute febrile illness (AFI) can often be difficult and misleading. This can mean that opportunities for preventive measures early on in an outbreak are missed. In any outbreak, descriptive epidemiological analyses are valuable in helping to ascertain the cause of the outbreak.

Local food policies can help promote local foods and improve health: a case study from the Federated States of Micronesia.

The Federated States of Micronesia (FSM) and other countries throughout the Pacific are facing an epidemic of non-communicable disease health problems. These are directly related to the increased consumption of unhealthy imported processed foods, the neglect of traditional food systems, and lifestyle changes, including decreased physical activity. The FSM faces the double burden of malnutrition with both non-communicable diseases and micronutrient deficiencies, including vitamin A deficiency and anemia. To help increase the use of traditional island foods and improve health, the Island Food Community of Pohnpei has initiated a program in the FSM to support and promote local food policies, along with its Go Local awareness campaign. Such local food policies are defined broadly and include individual and family commitments, community group local food policies and policies established by government, including presidential proclamations and increased taxation on soft drinks. The aim of this paper is to describe this work. An inter-agency, community- and research-based, participatory and media approach was used. Partners are both non-governmental and governmental. The use of continuing awareness work along with local food policy establishment and the acknowledgement of the individuals and groups involved are essential. The work is still in the preliminary stage but ad hoc examples show that this approach has had success in increased awareness on health issues and improving dietary intake on both an individual and group basis. This indicates that further use of local food policies could have an instrumental impact in FSM as well as other Pacific Island countries in promoting local foods and improving dietary intake and health, including the control of non-communicable diseases and other dietary-related health problems.

Zika virus outbreak on Yap Island, Federated States of Micronesia.

BACKGROUND: In 2007, physicians on Yap Island reported an outbreak of illness characterized by rash, conjunctivitis, and arthralgia. Although serum from some patients had IgM antibody against dengue virus, the illness seemed clinically distinct from previously detected dengue. Subsequent testing with the use of consensus primers detected Zika virus RNA in the serum of the patients but no dengue virus or other arboviral RNA. No previous outbreaks and only 14 cases of Zika virus disease have been previously documented. METHODS: We obtained serum samples from patients and interviewed patients for information on clinical signs and symptoms. Zika virus disease was confirmed by a finding of Zika virus RNA or a specific neutralizing antibody response to Zika virus in the serum. Patients with IgM antibody against Zika virus who had a potentially cross-reactive neutralizing-antibody response were classified as having probable Zika virus disease. We conducted a household survey to estimate the proportion of Yap residents with IgM antibody against Zika virus and to identify possible mosquito vectors of Zika virus. RESULTS: We identified 49 confirmed and 59 probable cases of Zika virus disease. The patients resided in 9 of the 10 municipalities on Yap. Rash, fever, arthralgia, and conjunctivitis were common symptoms. No hospitalizations, hemorrhagic manifestations, or deaths due to Zika virus were reported. We estimated that 73% (95% confidence interval, 68 to 77) of Yap residents 3 years of age or older had been recently infected with Zika virus. Aedes hensilli was the predominant mosquito species identified. CONCLUSIONS: This outbreak of Zika virus illness in Micronesia represents transmission of Zika virus outside Africa and Asia. Although most patients had mild illness, clinicians and public health officials should be aware of the risk of further expansion of Zika virus transmission.