The bibliometric landscape of infectious disease research in Panama (1990-2019)

Background

This work aims to analyze the landscape of scientific publications on subjects related to One Health and infectious diseases in Panama. The research questions are: How does the One Health research landscape look like in Panama? Are historical research efforts aligned with the One Health concept? What infectious diseases have received more attention from the local scientific community since 1990?

Methods

Boolean searches on the Web of Science, SCOPUS and PubMed were undertaken to evaluate the main trends of publications related to One Health and infectious disease research in the country of Panama, between 1990 and 2019.

Results

4546 publications were identified since 1990, including 3564 peer-reviewed articles interconnected with One Health related descriptors, and 211 articles focused particularly on infectious diseases. A pattern of exponential growth in the number of publications with various contributions from Panamanian institutions was observed. The rate of multidisciplinary research was moderate, whereas those of interinstitutional and intersectoral research ranged from low to very low. Research efforts have centered largely on protozoan, neglected and arthropod-borne diseases with a strong emphasis on malaria, Chagas and leishmaniasis.

Conclusion

Panama has scientific capabilities on One Health to tackle future infectious disease threats, but the official collaboration schemes and strategic investment to develop further competencies need to be conciliated with modern times, aka the pandemics era. The main proposition here, addressed to the government of Panama, is to launch a One Health regional center to promote multidisciplinary, interinstitutional and intersectoral research activities in Panama and beyond.

Two Decades of Wildlife Pathogen Surveillance: Case Study of Choclo orthohantavirus and Its Wild Reservoir Oligoryzomys costaricensis

The Costa Rican pygmy rice rat (Oligoryzomys costaricensis) is the primary reservoir of Choclo orthohantavirus (CHOV), the causal agent of hantavirus disease, pulmonary syndrome, and fever in humans in Panama. Since the emergence of CHOV in early 2000, we have systematically sampled and archived rodents from >150 sites across Panama to establish a baseline understanding of the host and virus, producing a permanent archive of holistic specimens that we are now probing in greater detail. We summarize these collections and explore preliminary habitat/virus associations to guide future wildlife surveillance and public health efforts related to CHOV and other zoonotic pathogens. Host sequences of the mitochondrial cytochrome b gene form a single monophyletic clade in Panama, despite wide distribution across Panama. Seropositive samples were concentrated in the central region of western Panama, consistent with the ecology of this agricultural commensal and the higher incidence of CHOV in humans in that region. Hantavirus seroprevalence in the pygmy rice rat was >15% overall, with the highest prevalence in agricultural areas (21%) and the lowest prevalence in shrublands (11%). Host-pathogen distribution, transmission dynamics, genomic evolution, and habitat affinities can be derived from the preserved samples, which include frozen tissues, and now provide a foundation for expanded investigations of orthohantaviruses in Panama.

Neuromyelitis Optica Spectrum Disorder in Central America and the Caribbean: A Multinational Clinical Characterization Study

Here, a study of NMOSD in Central America and the Caribbean with a multinational collaborative, multicentric and descriptive approach involving 25 institutions from 9 countries is presented. Demographics, clinical manifestations, expanded disability scale status (EDSS), brain and spinal cord MRI, serological anti-AQP4-IgG and anti-MOG-IgG antibodies, and cerebrospinal fluid (CSF) oligoclonal bands were included. A central serological repository utilized the cell-based assay. The specimens outside of this network employed diverse methodologies. Data were collected at the Gorgas Commemorative Institute of Health Studies (ICGES), Panama, and included 186 subjects, of which 84% were females (sex ratio of 5.6:1). Mestizos constituted 72% of the study group. The median age was 42.5 years (IQR: 32.0–52.0). Associated autoimmune diseases (8.1%) were myasthenia gravis, Sjögren’s syndrome and systemic lupus erythematosus. The most common manifestation was optic neuritis-transverse myelitis (42.5%). A relapsing course was described in 72.3% of cases. EDSS scores of 0–3.5 were reported in 57.2% of cases and higher than 7.0 in 14.5%. Positive anti-AQP4-IgG antibody occurred in 59.8% and anti-MOG-IgG antibody in 11.5% of individuals. Antibody testing was lacking for 13.4% of patients. The estimated crude prevalence of NMOSD from Panama and the Dominican Republic was 1.62/100,000 (incidence of 0.08–0.41) and 0.73/100,000 (incidence 0.02–0.14), respectively. This multinational study contributes additional insights and data on the understanding of NMOSD in this Latin American region.

Cytokine Profiles and Antibody Response Associated to Choclo Orthohantavirus Infection

Background

New World Hantaviruses (NWHs) are the etiological agent underlying hantavirus cardiopulmonary syndrome (HCPS), a severe respiratory disease with high mortality rates in humans. In Panama, infections with Choclo Orthohantavirus (CHOV) cause a much milder illness characterized by higher seroprevalence and lower mortality rates. To date, the cytokine profiles and antibody responses associated with this milder form of HCPS have not been defined. Therefore, in this study, we examined immune serological profiles associated with CHOV infections.

Methods

For this retrospective study, sera from fifteen individuals with acute CHOV-induced HCPS, were analyzed alongside sera from fifteen convalescent phase individuals and thirty-three asymptomatic, CHOV-seropositive individuals. Cytokine profiles were analyzed by multiplex immunoassay. Antibody subclasses, binding, and neutralization against CHOV-glycoprotein (CHOV-GP) were evaluated by ELISA, and flow cytometry.

Results

High titers of IFNγ, IL-4, IL-8, and IL-10 serum cytokines were found in the acute individuals. Elevated IL-4 serum levels were found in convalescent and asymptomatic seropositive individuals. High titers of IgG1 subclass were observed across the three cohorts analyzed. Neutralizing antibody response against CHOV-GP was detectable in few acute individuals but was strong in both convalescent and asymptomatic seropositive individuals.

Conclusion

A Th1/Th2 cytokine signature is characteristic during acute mild HCPS caused by CHOV infection. High expression of Th2 and IL-8 cytokines are correlated with clinical parameters in acute mild HCPS. In addition, a strong IL-4 signature is associated with different cohorts, including asymptomatic individuals. Furthermore, asymptomatic individuals presented high titers of neutralizing antibodies.

Clinical and Serological Findings of Madariaga and Venezuelan Equine Encephalitis Viral Infections: A Follow-up Study 5 Years After an Outbreak in Panama

BACKGROUND

Human cases of Madariaga virus (MADV) infection were first detected during an outbreak in 2010 in eastern Panama, where Venezuelan equine encephalitis virus (VEEV) also circulates. Little is known about the long-term consequences of either alphavirus infection.

METHODS

A follow-up study of the 2010 outbreak was undertaken in 2015. An additional survey was carried out 2 weeks after a separate 2017 alphavirus outbreak in a neighboring population in eastern Panama. Serological studies and statistical analyses were undertaken in both populations.

RESULTS

Among the originally alphavirus-seronegative participants (n = 35 of 65), seroconversion was observed at a rate of 14.3% (95% CI, 4.8%-30.3%) for MADV and 8.6% (95% CI, 1.8%-23.1%) for VEEV over 5 years. Among the originally MADV-seropositive participants (n = 14 of 65), VEEV seroconversion occurred in 35.7% (95% CI, 12.8%-64.9%). In the VEEV-seropositive participants (n = 16 of 65), MADV seroconversion occurred in 6.3% (95% CI, 0.2%-30.2%). MADV seroreversion was observed in 14.3% (95% CI, 1.8%-42.8%) of those who were originally seropositive in 2010. VEEV seroconversion in the baseline MADV-seropositive participants was significantly higher than in alphavirus-negative participants. In the population sampled in 2017, MADV and VEEV seroprevalence was 13.2% and 16.8%, respectively. Memory loss, insomnia, irritability, and seizures were reported significantly more frequently in alphavirus-seropositive participants than in seronegative participants.

CONCLUSIONS

High rates of seroconversion to MADV and VEEV over 5 years suggest frequent circulation of both viruses in Panama. Enhanced susceptibility to VEEV infection may be conferred by MADV infection. We provide evidence of persistent neurologic symptoms up to 5 years following MADV and VEEV exposure.

Human and Equine Infection with Alphaviruses and Flaviviruses in Panamá during 2010: A Cross-Sectional Study of Household Contacts during an Encephalitis Outbreak

Members of the genera Alphavirus (family Togaviridae) and Flavivirus (family Flaviridae) are important zoonotic human and equine etiologic agents of neurologic diseases in the New World. In 2010, an outbreak of Madariaga virus (MADV; formerly eastern equine encephalitis virus) and Venezuelan equine encephalitis virus (VEEV) infections was reported in eastern Panamá. We further characterized the epidemiology of the outbreak by studying household contacts of confirmed human cases and of equine cases with neurological disease signs. Serum samples were screened using a hemagglutination inhibition test, and human results were confirmed using plaque reduction neutralization tests. A generalized linear model was used to evaluate the human MADV and VEEV seroprevalence ratios by age (in tercile) and gender. Overall, antibody prevalence for human MADV infection was 19.4%, VEEV 33.3%, and Mayaro virus 1.4%. In comparison with individuals aged 2-20 years, people from older age groups (21-41 and > 41 years) were five times more likely to have antibodies against VEEV, whereas the MADV prevalence ratio was independent of age. The overall seroprevalence of MADV in equids was 26.3%, VEEV 29.4%, West Nile virus (WNV) 2.6%, and St. Louis encephalitis virus (SLEV) was 63.0%. Taken together, our results suggest that multiple arboviruses are circulating in human and equine populations in Panamá. Our findings of a lack of increase in the seroprevalence ratio with age support the hypothesis of recent MADV exposure to people living in the affected region.

Indigenous and tribal peoples' health (The Lancet-Lowitja Institute Global Collaboration): a population study

BACKGROUND

International studies of the health of Indigenous and tribal peoples provide important public health insights. Reliable data are required for the development of policy and health services. Previous studies document poorer outcomes for Indigenous peoples compared with benchmark populations, but have been restricted in their coverage of countries or the range of health indicators. Our objective is to describe the health and social status of Indigenous and tribal peoples relative to benchmark populations from a sample of countries.

METHODS

Collaborators with expertise in Indigenous health data systems were identified for each country. Data were obtained for population, life expectancy at birth, infant mortality, low and high birthweight, maternal mortality, nutritional status, educational attainment, and economic status. Data sources consisted of governmental data, data from non-governmental organisations such as UNICEF, and other research. Absolute and relative differences were calculated.

FINDINGS

Our data (23 countries, 28 populations) provide evidence of poorer health and social outcomes for Indigenous peoples than for non-Indigenous populations. However, this is not uniformly the case, and the size of the rate difference varies. We document poorer outcomes for Indigenous populations for: life expectancy at birth for 16 of 18 populations with a difference greater than 1 year in 15 populations; infant mortality rate for 18 of 19 populations with a rate difference greater than one per 1000 livebirths in 16 populations; maternal mortality in ten populations; low birthweight with the rate difference greater than 2% in three populations; high birthweight with the rate difference greater than 2% in one population; child malnutrition for ten of 16 populations with a difference greater than 10% in five populations; child obesity for eight of 12 populations with a difference greater than 5% in four populations; adult obesity for seven of 13 populations with a difference greater than 10% in four populations; educational attainment for 26 of 27 populations with a difference greater than 1% in 24 populations; and economic status for 15 of 18 populations with a difference greater than 1% in 14 populations.

INTERPRETATION

We systematically collated data across a broader sample of countries and indicators than done in previous studies. Taking into account the UN Sustainable Development Goals, we recommend that national governments develop targeted policy responses to Indigenous health, improving access to health services, and Indigenous data within national surveillance systems.

FUNDING

The Lowitja Institute.

Indigenous and tribal peoples' health (The Lancet-Lowitja Institute Global Collaboration): a population study

BACKGROUND

International studies of the health of Indigenous and tribal peoples provide important public health insights. Reliable data are required for the development of policy and health services. Previous studies document poorer outcomes for Indigenous peoples compared with benchmark populations, but have been restricted in their coverage of countries or the range of health indicators. Our objective is to describe the health and social status of Indigenous and tribal peoples relative to benchmark populations from a sample of countries.

METHODS

Collaborators with expertise in Indigenous health data systems were identified for each country. Data were obtained for population, life expectancy at birth, infant mortality, low and high birthweight, maternal mortality, nutritional status, educational attainment, and economic status. Data sources consisted of governmental data, data from non-governmental organisations such as UNICEF, and other research. Absolute and relative differences were calculated.

FINDINGS

Our data (23 countries, 28 populations) provide evidence of poorer health and social outcomes for Indigenous peoples than for non-Indigenous populations. However, this is not uniformly the case, and the size of the rate difference varies. We document poorer outcomes for Indigenous populations for: life expectancy at birth for 16 of 18 populations with a difference greater than 1 year in 15 populations; infant mortality rate for 18 of 19 populations with a rate difference greater than one per 1000 livebirths in 16 populations; maternal mortality in ten populations; low birthweight with the rate difference greater than 2% in three populations; high birthweight with the rate difference greater than 2% in one population; child malnutrition for ten of 16 populations with a difference greater than 10% in five populations; child obesity for eight of 12 populations with a difference greater than 5% in four populations; adult obesity for seven of 13 populations with a difference greater than 10% in four populations; educational attainment for 26 of 27 populations with a difference greater than 1% in 24 populations; and economic status for 15 of 18 populations with a difference greater than 1% in 14 populations.

INTERPRETATION

We systematically collated data across a broader sample of countries and indicators than done in previous studies. Taking into account the UN Sustainable Development Goals, we recommend that national governments develop targeted policy responses to Indigenous health, improving access to health services, and Indigenous data within national surveillance systems.

FUNDING

The Lowitja Institute.

Epidemiology of Emergent Madariaga Encephalitis in a Region with Endemic Venezuelan Equine Encephalitis: Initial Host Studies and Human Cross-Sectional Study in Darien, Panama

Background

Neurotropic arboviral infections are an important cause of encephalitis. A zoonotic, vector-borne alphavirus, Madariaga virus (MADV; formerly known as South American eastern equine encephalitis virus), caused its first documented human outbreak in 2010 in Darien, Panama, where the genetically similar Venezuelan equine encephalitis virus (VEEV) is endemic. We report the results of a seroprevalence survey of animals and humans, illustrating contrasting features of MADV and VEEV ecology and epidemiology.

Methods

Small mammals were trapped in 42 sites in Darien, Panama, using Sherman traps, Tomahawk traps, and mist nets for bats. Blood was tested for the presence of neutralizing antibodies to MADV and VEEV. In addition, bird sera collected in 2007 in Chagres, Panama, were tested for MADV and VEEV neutralizing antibodies. Viremia was ascertained by RT-PCR. Human exposure to these two viruses was determined by IgG ELISA, followed by plaque reduction neutralization tests. To identify relevant risk factors for MADV or VEEV exposure, logistic regression analysis was performed, and the most parsimonious model was selected based on the Akaike information criterion.

Results

The animal survey yielded 32 bats (16 species), 556 rodents (12 species), and 20 opossums (4 species). The short-tailed cane mouse (Zygodontomys brevicauda) found abundantly in pasture and farms, had the highest MADV seroprevalence (8.3%). For VEEV, the shrub and forest-dwelling long-whiskered rice rat (Transandinomys bolivaris) had the highest seroprevalence (19.0%). Viremia was detected in one animal (Z. brevicauda). Of the 159 bird sera (50 species) tested, none were positive for either virus. In humans (n = 770), neutralizing antibodies to MADV and VEEV were present in 4.8% and 31.5%, respectively. MADV seropositivity was positively associated with cattle ranching, farming, and fishing. Having VEEV antibodies and shrubs near the house diminished risk. Age, forest work, farming and fishing were risk factors for VEEV, while having MADV antibodies, glazed windows, waste pick-up and piped water were protective.

Conclusion

Our findings suggest that the short-tailed cane mouse and the long-whiskered rice rat serve as hosts for MADV and VEEV, respectively. The preferred habitat of these rodent species coincides with areas associated with human infection risk. Our findings also indicate that MADV emerged recently in humans, and that the transmission cycles of these two sympatric alphaviruses differ spatially and in host utilization.

Arthropod-borne viruses are important causes of encephalitis. In 2010, the first documented human outbreak of the mosquito-borne, zoonotic Madariaga virus (MADV) occurred in the Darien region of Panama. Neither its epidemiology nor its transmission cycle is understood. In this study, the authors searched for possible animal hosts of this virus, and sought to describe its epidemiology. They contrast the findings with those for Venezuelan equine encephalitis virus (VEEV), an endemic, genetically similar virus. Zygodontomys brevicauda, the short-tailed cane mouse, had the highest seroprevalence for MADV. This rodent species is most often found in pasture and farm land. Indeed, the risk factors for human MADV exposure were cattle ranching and farming. The animal with highest seroprevalence for VEEV, the long-whiskered rice rat (Transandinomys bolivaris), commonly occurs in forest, and the epidemiological risk factors included working in the forest. Farming and fishing were risk factors for exposure to both viruses, and having antibodies to one virus diminished the risk of being positive for the other. Increasing prevalence with age was seen for VEEV, confirming that VEEV is endemic in the region. This association was absent for MADV, suggesting that this virus emerged recently to infect humans.

Costing Dengue Fever Cases and Outbreaks: Recommendations from a Costing Dengue Working Group in the Americas

OBJECTIVES

The overall aim of this article was to present a step-by-step guideline for determining the costs associated with dengue in dengue-endemic countries of the Latin American and the Caribbean region and to illustrate how each of these steps can be applied in dengue costing studies.

METHODS

An expert panel was convened to develop standards for costing dengue so that over the next decade, decision makers will have access to improved information on the true cost of dengue in endemic countries of the Latin American and the Caribbean region. We described the outcome of the expert panel meeting, which resulted in the provision of a step-by-step dengue costing guideline that aims to provide direction to planners and program managers on how to estimate dengue economic burden studies, and provide a discussion forum of the methods used to cost dengue fever cases and outbreaks in a manner that should be accessible to persons with some familiarity with a cost study.

RESULTS

The guideline includes nine sequential steps: 1) definition of the scope of the study; 2) identification of the target population; 3) description of the study perspective; 4) definition of the time horizon; 5) calculation of the sample size; 6) definition of the unit of analysis; 7) identification of the cost items; 8) measurement and valuation of the cost items; and 9) handling of uncertainty. The trade-off between accurate, patient-level cost estimates and data availability constraints is discussed.

CONCLUSIONS

The current guideline is the result of constructive collaboration among a multidisciplinary research team to better ascertain the true economic burden of dengue across countries of the region.

The impact of cerebrovascular disease in Panama

BACKGROUND

In Latin America, the cerebrovascular disease is considered a catastrophic public health problem. The objective of this publication is to describe the demographic characteristics and risk factors of cerebrovascular disease in Panama.

METHODS

A hospital-based stroke registry was carried out between 2005 and 2006 to record all patients with cerebrovascular disease admitted to the two major teaching public hospital in Panama City. A comparative analysis was realized of the risk factor of two regional survey studies in Panamá and Colón province on 2007 and 2010.

RESULTS

Sixty-three percent of the stroke was ischemic, and high blood pressure was the most common risk factor with 73%; the intrahospital mortality was 28·4%. In a National Health and Quality of Life Survey carried out in 2007, the crude prevalence of cerebrovascular disease was 0·7%. High blood pressure (22%), smoking (9·1%), alcoholism (10·8%), dyslipidemia (8·7%), and diabetes mellitus (5·4%) were the most common risk factors. In 2010, a survey to find out the Prevalence of Risk Factor Associated to Cardiovascular disease in the province of Panama and Colon found that crude prevalence of cerebrovascular disease was 1·6%. High blood pressure (28·4%), dyslipidemia (20·8%), and alcoholism (17·0%) were the most common risk factors.

CONCLUSION

Since 2013, both hospitals' intravenous thrombolytic therapy program has been successfully applied as public health policy. A successful campaign on healthy lifestyle must be strengthened through a comprehensive approach with other public sectors in order to have an impact on the population, particularly in children and adolescents.

Hantavirus fever without pulmonary syndrome in Panama

In Panama, hantavirus pulmonary syndrome (HPS) is caused by Choclo virus, a species phylogenetically related to Andes and Maporal viruses. Up to 60% of the population has been positive for specific serum antibody in community-based surveys, but mortality is very uncommon. In four western Panama clinics, we tested individuals presenting with a severe febrile prodrome for acute hantavirus (HV) infection by immunoglobulin M enzyme-linked immunosorbent assay and reverse transcription polymerase chain reaction as well as clinically similar infections, such as dengue and leptospirosis. From 2006 to 2009, at least 21% of 117 patients diagnosed with HV infection had HV Fever (HF) with no evidence of pulmonary edema (no respiratory distress or radiographic lung infiltrates), and 44% of patients had very mild HPS (radiographic pulmonary edema but no respiratory insufficiency). HV infection caused by Choclo virus in Panama presents often as HF, which contrasts with HV in the Americas but is consistent with the high seroprevalence in endemic regions.

Incidence rate for hantavirus infections without pulmonary syndrome, Panama

During 2001–2007, to determine incidence of all hantavirus infections, including those without pulmonary syndrome, in western Panama, we conducted 11 communitywide surveys. Among 1,129 persons, antibody prevalence was 16.5%–60.4%. Repeat surveys of 476 found that patients who seroconverted outnumbered patients with hantavirus pulmonary syndrome by 14 to 1.

Confirmation of Choclo virus as the cause of hantavirus cardiopulmonary syndrome and high serum antibody prevalence in Panama

Choclo virus (CHOV) was described in sigmodontine rodents, Oligoryzomys fulvescens, and humans during an outbreak of hantavirus cardiopulmonary syndrome (HCPS) in 1999-2000 in western Panama. Although HCPS is rare, hantavirus-specific serum antibody prevalence among the general population is high suggesting that CHOV may cause many mild or asymptomatic infections. The goals of this study were to confirm the role of CHOV in HCPS and in the frequently detected serum antibody and to establish the phylogenetic relationship with other New World hantaviruses. CHOV was cultured to facilitate the sequencing of the small (S) and medium (M) segments and to perform CHOV-specific serum neutralization antibody assays. Sequences of the S and M segments found a close relationship to other Oligoryzomys-borne hantaviruses in the Americas, highly conserved terminal nucleotides, and no evidence for recombination events. The maximum likelihood and maximum parsimony analyses of complete M segment nucleotide sequences indicate a close relationship to Maporal and Laguna Negra viruses, found at the base of the South American clade. In a focus neutralization assay acute and convalescent sera from six Panamanian HCPS patients neutralized CHOV in dilutions from 1:200 to 1:6,400. In a sample of antibody-positive adults without a history of HCPS, 9 of 10 sera neutralized CHOV in dilutions ranging from 1:100 to 1:6,400. Although cross-neutralization with other sympatric hantaviruses not yet associated with human disease is possible, CHOV appears to be the causal agent for most of the mild or asymptomatic hantavirus infections, as well as HCPS, in Panama.

Convalescent pulmonary dysfunction following hantavirus pulmonary syndrome in Panama and the United States

The objective of this study was to document persistent pulmonary symptoms and pulmonary function abnormalities in adults surviving hantavirus pulmonary syndrome (HPS). Acute infection by most hantaviruses result in mortality rates of 25–35%, while in Panama the mortality rate of 10% is contrasted by an unusually high incidence. In all types of HPS, the viral prodrome, cardiopulmonary phase due to massive pulmonary capillary leak syndrome, and spontaneous diuresis are followed by a convalescent phase with exertional dyspnea for 3–4 weeks, but the frequency of persistent symptoms is not known. In this observational study of a convenience sample, 14 survivors of HPS caused by Choclo virus infection in Panama and 9 survivors of HPS caused by Sin Nombre virus infection in New Mexico completed a questionnaire and pulmonary function tests up to 8 years after infection. In both groups, exertional dyspnea persisted for 1–2 years after acute infection in 43% (Panama) and 77% (New Mexico) of survivors surveyed. Reduction in midexpiratory flows (FEF_25–75%), increased residual volume (RV), and reduced diffusion capacity (D_LCO/VA) also were common in both populations; but the severity of reduced expiratory flow did not correlate with exertional dyspnea. Symptoms referable to previous hantavirus infection had resolved within 3 years of acute infection in most but not all patients in the Panama group. Temporary exertional dyspnea and reduced expiratory flow are common in early convalescence after HPS but resolves in almost all patients.

Profile of the first cases hospitalized due to influenza A (H1N1) in Panama City, Panama. May-June 2009

INTRODUCTION

In April 2009, a novel influenza A (H1N1) virus was identified in patients from Mexico and the United States. From 8 May through 25 June 2009, in the Republic of Panama, 467 cases infected with the same virus were identified, 13 of which were hospitalized at the Santo Tomas Hospital in Panama City. Up to the date of this report, no deaths have been reported in Panama. This study presents the first thirteen cases of Influenza A (H1N1) 2009 that were hospitalized in Panama City.

METHODOLOGY

The Santo Tomas Hospital (HST), a third-level institution of the Ministry of Health (MINSA) for adult health care (patients above the age of 14), was designated as the reference center for treating these cases. For this purpose, the norms and criteria established by the system were followed and every patient (case) presenting flu-like symptoms was included (fever equal or greater than 38 masculineC (100.4 masculineF), cough, sore throat, rhinorrhea, lethargy in children under the age of one, and respiratory distress).

RESULTS

Seventy-six patients were hospitalized as suspected cases for infection with the influenza A H1N1 2009 virus, of which 13 (17.1%) were confirmed as positive. The clinical picture was characterized by fever (100%), cough (92.3%), rhinorrhea (69.2%), malaise (53.8%), headache (53.8%), and only one case presented gastrointestinal symptoms (diarrhoea). The male:female ratio was 1:2.2.

CONCLUSION

The knowledge and technology translation previously acquired through courses to the HST health care providers were the key in controlling the first influenza A (H1N1) 2009 cases.

Cost of dengue cases in eight countries in the Americas and Asia: a prospective study

Despite the growing worldwide burden of dengue fever, the global economic impact of dengue illness is poorly documented. Using a common protocol, we present the first multicountry estimates of the direct and indirect costs of dengue cases in eight American and Asian countries. We conducted prospective studies of the cost of dengue in five countries in the Americas (Brazil, El Salvador, Guatemala, Panama, and Venezuela) and three countries in Asia (Cambodia, Malaysia, and Thailand). All studies followed the same core protocol with interviews and medical record reviews. The study populations were patients treated in ambulatory and hospital settings with a clinical diagnosis of dengue. Most studies were performed in 2005. Costs are in 2005 international dollars (I$). We studied 1,695 patients (48% pediatric and 52% adult); none died. The average illness lasted 11.9 days for ambulatory patients and 11.0 days for hospitalized patients. Among hospitalized patients, students lost 5.6 days of school, whereas those working lost 9.9 work days per average dengue episode. Overall mean costs were I$514 and I$1,394 for an ambulatory and hospitalized case, respectively. With an annual average of 574,000 cases reported, the aggregate annual economic cost of dengue for the eight study countries is at least I$587 million. Preliminary adjustment for under-reporting could raise this total to $1.8 billion, and incorporating costs of dengue surveillance and vector control would raise the amount further. Dengue imposes substantial costs on both the health sector and the overall economy.

Clinical characteristics and national economic cost of the 2005 dengue epidemic in Panama

In 2005, Panama experienced the largest dengue epidemic since 1993. We conducted both a prospective clinical and a national economic study. The full cost analysis measured costs of dengue cases and of dengue control efforts in the entire country. Costs are in 2005 US$. Ambulatory patients were 130 of the 136 participants, with 82% adults (18+) and 62% women. Duration of fever and illness averaged 6.1 (standard deviation [SD], 5.3) and 21.2 (SD 13.5) days, respectively. Loss in quality of life averaged 67% (SD 21) during the worst days of illness. An average ambulatory and hospitalized case cost $332 and $1,065, respectively. Although 5,489 cases were officially reported, the Ministry of Health (MOH) estimated 32,900 actual cases, implying a total cost of $11.8 million. Additionally, estimated government spending on dengue control efforts was $5 million. This dengue epidemic had a major disease impact and an economic cost of $16.9 million ($5.22 per capita).

Outbreak of hantavirus pulmonary syndrome, Los Santos, Panama, 1999-2000

An outbreak of hantavirus pulmonary syndrome occurred in the province of Los Santos, Panama, in late 1999 and early 2000. Eleven cases were identified; 9 were confirmed by serology. Three cases were fatal; however, no confirmed case-patient died. Case-neighborhood serologic surveys resulted in an overall hantavirus antibody prevalence of 13% among household and neighborhood members from the outbreak foci. Epidemiologic investigations did not suggest person-to-person transmission of hantavirus infection. By use of Sin Nombre virus antigen, hantavirus antibodies were detected in Oligoryzomys fulvescens and Zygodontomys brevicauda cherriei. This outbreak resulted in the first documented cases of human hantavirus infections in Central America.

High seroprevalence of hantavirus infection on the Azuero peninsula of Panama

The first outbreak of hantavirus pulmonary syndrome (HPS) in Central America was documented on the Azuero peninsula of Panama in late 1999 and 2000. Reverse transcriptase-polymerase chain reaction evidence implicated only Choclo virus in symptomatic HPS with a mortality rate of 20%, although two rodent-borne hantaviruses (Choclo virus and Calabazo virus) were identified in the peridomestic habitat. Neighborhood serosurveys around case households found seroprevalence rates as high as 30%, the highest in the Americas except for western Paraguay. We report here population-based serosurveys for 1,346 adults and children in four communities, three on the Azuero peninsula and one in adjacent central Panama. Overall seroprevalence ranged from 33.2% in a population engaged in farming and fishing on Isla de Cañas, to 16.3% and 21.2% in two mainland agricultural communities, to 3.1% in central Panama, with a modest male predominance of 1.2:1. Nine percent of children 4-10 years old were seropositive, and seroprevalence increased with age in all communities, with highest levels of 52% in those 41-50 years old cohort on Isla de Cañas. Univariate analysis identified correlations between seroprevalence and multiple agricultural and animal husbandry activities. However, stepwise logistic regression models identified only raising animals (cows, pigs, goats, poultry) and fishing as significant independent variables. Human infection with hantavirus on the Azuero peninsula, either with Choclo virus or combined with Calabazo virus, is frequent but rarely results in hospitalization due to respiratory illnesses resembling HPS.

Risk factors for human T cell lymphotropic virus type II infection among the Guaymi Indians of Panama

To examine risk factors for human T cell lymphotropic virus type II (HTLV-II) infection, a case-control study was conducted among the Guaymi Indians of Panama. In females, HTLV-II seropositivity was associated with early sexual intercourse (</=13 vs. >15 years; odds ratio [OR], 2.50; 95% confidence interval [CI], 1.11-6.14) and number of lifetime sex partners. One partner increased risk of seropositivity by 30% (OR, 1.30; CI, 1.05-1.64), and risk increased with number of partners. Similar risk was associated with number of long-term sexual relationships. Among males, intercourse with prostitutes was associated with HTLV-II seropositivity (OR, 1.68; CI, 1.04-2.72). These data support a role for sexual transmission in HTLV-II infection. Association of seropositivity with primary residence in a traditional village (OR, 3.75; CI, 1.02-15.38) and lack of formal education (0 vs. >6 years [OR, 3.89; CI, 1.67-9.82]) observed in males may reflect differences in sexual practices associated with acculturation.

Evidence for sexual and mother-to-child transmission of human T lymphotropic virus type II among Guaymi Indians, Panama

Guaymi Indians, a non-intravenous drug-using population in which human T cell lymphotropic virus type II (HTLV-II) is endemic, were studied in Changuinola, Panama, to identify the prevalence and modes of transmission of HTLV-II. A population-based survey showed that 352 (9.5%) of the 3686 participants were seropositive for HTLV-II. Infection rates were the same for male and female subjects and increased significantly with age, beginning in young adulthood. HTLV-II infection status was highly concordant among spouses (P < .001) and between mother and child; of children aged 1-10 years, 36 of 219 born to seropositive mothers were seropositive compared with 3 of 997 born to seronegative mothers (P < .001). The strong associations of HTLV-II infection with age and with an infected spouse in adults and of infection in children with infection in their mothers strongly suggest sexual and mother-to-child transmission of HTLV-II in this population.