Hantavirus in Panama: Twenty Years of Epidemiological Surveillance Experience.

Twenty years have passed since the emergence of hantavirus zoonosis in Panama at the beginning of this millennium. We provide an overview of epidemiological surveillance of hantavirus disease (hantavirus pulmonary syndrome and hantavirus fever) during the period 1999-2019 by including all reported and confirmed cases according to the case definition established by the health authority. Our findings reveal that hantavirus disease is a low-frequency disease, affecting primarily young people, with a relatively low case-fatality rate compared to other hantaviruses in the Americas (e.g., ANDV and SNV). It presents an annual variation with peaks every 4-5 years and an interannual variation influenced by agricultural activities. Hantavirus disease is endemic in about 27% of Panama, which corresponds to agroecological conditions that favor the population dynamics of the rodent host, Oligoryzomys costaricensis and the virus (Choclo orthohantavirus) responsible for hantavirus disease. However, this does not rule out the existence of other endemic areas to be characterized. Undoubtedly, decentralization of the laboratory test and dissemination of evidence-based surveillance guidelines and regulations have standardized and improved diagnosis, notification at the level of the primary care system, and management in intensive care units nationwide.

Adult immunization practices, challenges and opportunities in Central America and the Caribbean: Advisory board proceedings.

As individuals age, they become increasingly prone to infectious diseases, many of which are vaccine-preventable diseases (VPDs). Adult immunization has become a public health priority in the modern era, yet VPDs vaccination rates for adults are low worldwide. In Central America and Caribbean, national recommendations and vaccination practices in adults differ across countries, and adult vaccination coverage data are limited. An advisory board comprised infectious disease experts, pulmonologists, geriatricians, occupational health, and public health professionals for Central America and Dominican Republic was convened to: a) describe adult immunization practices in these countries; b) discuss challenges and barriers to adult vaccination; and c) find strategies to increase awareness about VPDs. The advisory board discussions reflect that national immunization guidelines typically do not include routine vaccine recommendations for all adults, but rather focus on those with risk factors. This is the case for influenza, pneumococcal, and hepatitis B immunizations. Overall, knowledge lacks about the VPD burden among health-care professionals and the general public. Even more, there is insufficient information on vaccinology for students in medical schools. Actions from the responsible authorities - medical schools and scientific societies which can advocate for vaccination and a better knowledge in vaccinology - can help address these issues. A preventive medicine culture in the workplace may contribute to the advancement of public opinion on vaccination. Promoting vaccine education and research could be facilitated via working groups formed by disease experts, public and private sectors, and supranational authorities, in an ethical and transparent manner.

Molecular Epidemiology of Dengue in Panama: 25 Years of Circulation.

Dengue virus (DENV) is the most prevalent arbovirus in terms of human public health importance globally. In addition to DENV epidemiological surveillance, genomic surveillance may help investigators understand the epidemiological dynamics, geographic distribution, and temporal patterns of DENV circulation. Herein, we aimed to reconstruct the molecular epidemiology and phylogeny of DENV in Panama to connect the epidemiological history of DENV dispersal and circulation in Latin America. We retrospectively analyzed the epidemiological data obtained during 25 years of DENV surveillance in Panama. DENV was reintroduced in Panama in 1993 after a 35 year absence of autochthonous transmission. The increase in the number of total dengue cases has been accompanied by an increase in severe and fatal cases, with the highest case fatality rate recorded in 2011. All four serotypes were detected in Panama, which is characterized by serotype replacement and/or co-circulation of multiple serotypes. Phylogenetic analysis of datasets collected from envelope (E) gene sequences obtained from viruses isolated from human sera demonstrated that circulating viruses were highly diverse and clustered in distinct clades, with co-circulation of clades from the same genotype. Our analyses also suggest that Panamanian strains were related to viruses from different regions of the Americas, suggesting a continuous exchange of viruses within the Americas.

Revising antimalarial drug policy in Central America: experience in Panama.

Panama is the first country in the Central American region that has officially discarded chloroquine as a first-line drug to treat Plasmodium falciparum cases. Here we describe the clinical and molecular findings from autochthonous P. falciparum fatal cases, and the epidemiological situation that led to a change in the national antimalarial drug policy. Our results illustrate the potential pathogenicity of the strain of P. falciparum circulating in the country and provide molecular evidence of parasite resistance to chloroquine and antifolate drugs. The public health threats of these findings for the Central American region are discussed.

Unusual pattern of chikungunya virus epidemic in the Americas, the Panamanian experience.

BACKGROUND: Chikungunya virus (CHIKV) typically causes explosive epidemics of fever, rash and polyarthralgia after its introduction into naïve populations. Since its introduction in Panama in May of 2014, few autochthonous cases have been reported; most of them were found within limited outbreaks in Panama City in 2014 and Puerto Obaldia town, near the Caribbean border with Colombia in 2015. In order to confirm that Panama had few CHIKV cases compared with neighboring countries, we perform an epidemiological analysis of chikungunya cases reported from May 2014 to July 2015. Moreover, to understand this paucity of confirmed CHIKV cases, a vectorial analysis in the counties where these cases were reported was performed. METHODS: Chikungunya cases were identified at medical centers and notified to health authorities. Sera samples were analyzed at Gorgas Memorial Institute for viral RNA and CHIKV-specific antibody detection. RESULTS: A total of 413 suspected cases of CHIKV infections were reported, with incidence rates of 0.5 and 0.7 per 100,000 inhabitants in 2014 and 2015, respectively. During this period, 38.6% of CHIKV cases were autochthonous with rash and polyarthralgia as predominant symptoms. CHIKV and DENV incidence ratios were 1:306 and 1:34, respectively. A phylogenetic analysis of E1/E2 genomic segment indicates that the outbreak strains belong to the Asian genotype and cluster together with CHIKV isolates from other American countries during the same period. Statistical analysis of the National Vector Control program at the district level shows low and medium vector infestation level for most of the counties with CHIKV cases. This index was lower than for neighboring countries. CONCLUSIONS: Previous training of clinical, laboratory and vector workers allowed a good caption and detection of the chikungunya cases and fast intervention. It is possible that low/medium vector infestation level could explain in part the paucity of chikungunya infections in Panama.

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.

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.

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.