The triple epidemics of arboviruses in Feira de Santana, Brazilian Northeast: Epidemiological characteristics and diffusion patterns

Arboviruses are diseases of worldwide importance in the field of communicable diseases. In Brazil, the reemergence of dengue and the emergence of chikungunya and Zika since 2014 have led to epidemic waves of great magnitude and rapid spread. However, their diffusion patterns vary and change over time. This study analyzes the spatial diffusion of the simultaneous circulation of three arboviruses transmitted by the same vector in a large urban space over two epidemic waves in consecutive years. An ecological study of spatial and temporal aggregates on the occurrence of dengue, chikungunya, and Zika, from 2014 to 2019, in Feira de Santana, Bahia State, was carried out using data of cases reported to the national surveillance system. Four different methods were used to analyze the spatial diffusion: Kernel Estimation with sequential maps, cumulative nearest-neighbor ratios (NNI) over time, spatial correlograms and local autocorrelation changes (LISA) over time. From 2014-2019, there were 21,723 confirmed cases of arboviruses. The highest incidences were among women (496.9, 220.2, and 91.0 cases/100,000 women for dengue, chikungunya and Zika respectively). By age group, the highest incidences were from ages 10-19 years old (609.3 dengue cases/100,000), from 60 and more (306.7 chikungunya cases/100,000), and from 0-9 years old (124.1 Zika cases/100,000 inhabitants). The temporal distribution demonstrated two epidemic waves of simultaneous circulation in 2014 and 2015. Kernel maps indicate that arboviruses spread to neighboring areas near the first hotspots, suggesting an expansion diffusion pattern. The NNI, spatial correlograms and LISA changes results suggest expansion patterns for the three arboviruses in all periods. The spatial diffusion pattern of dengue, Zika, and chikungunya in the 2014-2015 epidemics in Feira de Santana was expansion. These findings are useful to guide prevention measures and reduce occurrence in other areas.

Patterns of signs, symptoms, and laboratory values associated with Zika, dengue, and undefined acute illnesses in a dengue endemic region: Secondary analysis of a prospective cohort study in southern Mexico

Objectives:

Dengue and Zika infections cause illnesses with overlapping clinical manifestations. The aim of this study was to explore the association of each of these infections with single or grouped clinical and laboratory parameters.

Methods:

Clinical and laboratory data were collected prospectively from a cohort of patients seeking care for symptoms meeting the Pan American Health Organization’s modified case-definition criteria for probable Zika virus infection. Zika and dengue were diagnosed with RT-PCR. The relationship of clinical characteristics and laboratory data with Zika, dengue, and undefined acute illness (UAI) was examined.

Results:

In the univariate models, localized rash and maculopapular exanthema were associated with Zika infection. Generalized rash, petechiae, and petechial purpuric rash were associated with dengue. Cough and confusion/disorientation were associated with UAI. Platelets were significantly lower in the dengue group. A conditional inference tree model showed poor sensitivity and positive predictive value for individual viral diagnoses.

Conclusions:

Clusters of signs, symptoms, and laboratory values evaluated in this study could not consistently differentiate Zika or dengue cases from UAI in the clinical setting at the individual patient level. We identified symptoms that are important to Zika and dengue in the univariate analyses, but predictive models were unreliable. Low platelet count was a distinctive feature of dengue.

Spatial modelling of the infestation indices of Aedes aegypti: an innovative strategy for vector control actions in developing countries

BACKGROUND

Larval indices such as the house index (HI), Breteau index (BI) and container index (CI) are widely used to interpret arbovirus vector density in surveillance programmes. However, the use of such data as an alarm signal is rarely considered consciously when planning programmes. The present study aims to investigate the spatial distribution pattern of the infestation of Aedes aegypti, considering the data available in the Ae. aegypti Infestation Index Rapid Survey (LIRAa) for the city of Campina Grande, Paraíba State in Brazil.

METHODS

The global and local Moran's indices were used in spatial analysis to measure the effects of spatial dependencies between neighbourhoods, using secondary data related to HI and BI gathered from surveillance service.

RESULTS

Our analysis shows that there is a predominance of high rates of mosquito infestation, placing Campina Grande at a near-constant risk of arbovirus outbreaks and epidemics. A highly significant Moran's index value (P < 0.001) was observed, indicating a positive spatial dependency between the neighbourhoods in Campina Grande. Using the Moran mapping and LISA mapping, the autocorrelation patterns of Ae. aegypti infestation rates among neighbourhoods have revealed hotpots that should be considered a priority to preventive actions of the entomological surveillance services. Predominance of high infestation rates and clearer relationships of these between neighbourhoods were observed between the months of May and July, the period with the highest rainfall in the city.

CONCLUSIONS

This analysis is an innovative strategy capable of providing detailed information on infestation locations to the relevant public health authorities, which will enable a more efficient allocation of resources, particularly for arbovirus prevention.

Characteristics of Zika virus infection among international travelers: A prospective study from a Spanish referral unit

BACKGROUND

From the first Zika virus (ZIKV) description, it has progressively widespread worldwide. We analyzed demographic, clinical, microbiologic and travel-related characteristic from returned patients from a ZIKV endemic country in a referral Tropical Medicine Unit.

METHOD

A prospective cohort study performed in a Spanish referral center with the aim of determining the significant factors associated with confirmed Zika virus (ZIKV) infection.

RESULTS

817 patients, (56% women, median age 36 [IQR, Interquartile Range: 32-42]) were enrolled. Most had returned from Latin America (n = 486; 59.4%), travelled for tourism (n = 404; 49.4%) and stayed a median of 18 days (IQR: 10-30). 602 (73.6%) presented symptoms, but only 25 (4%) were finally diagnosed with confirmed ZIKV infection (including two pregnant women, without adverse fetal outcomes), 88% (n:22) presented with fever and 92% (n:23) with rash. 56% (n:14) arthralgia and/or myalgia and 28% (n:7) conjunctivitis. The presence of conjunctivitis, fever and rash were associated with an 8.9 (95% CI: 2.2-34.9), 6.4 (95% CI: 1.2-33.3) and 72.3 (95% CI: 9.2-563.5) times greater probability of confirmed ZIKV infection, respectively.

CONCLUSION

Travel characteristics and clinical presentation may help clinicians to optimize requests for microbiological testing. Diagnosis of arboviriasis in travellers arriving form endemic areas remains a challenge for clinicians, but must be detected for the possible transmission outside endemic areas, where the vector is present.

Evaluation of serological test of Zika in an endemic area of flavivirus in the Colombian Caribbean

Abstract

The Zika virus (ZIKV) is an emerging flavivirus transmitted primarily through arthropods, endemic in Africa, Asia, and the Americas, and is considered a global threat by the World Health Organization.

Objective

To evaluate a commercial Zika virus test (IgG/IgM catalog number B815C, Biocan, Canada.

Methods

We evaluated 30 sera of patients diagnosed with Dengue, Leptospira, Malaria, Hantavirus, and Chikungunya. To establish the sensitivity of the test, two groups of sera were analyzed, the first one was patients with Zika RT-qPCR positive, and the second were patients RT-qPCR negative but with clinical suspicion of Zika.

Results

The specificity was of 23.3% (7/30), the sensitivity in acute patients with positive RT-qPCR was of 63.6%, the patients with clinical suspicion of Zika the sensitivity (IgM) was of 80% (n = 8/10). Overall sensitivity (IgM) of both groups was of 71.4% (15/21).

Conclusions

The test showed a low specificity to be used as a serological test in an endemic area of flavivirus infection.

Zika in Puerto Rico, 2016-2017: I Perspectives on the Social Crisis and Health Care Concerns

The social reaction to the Zika epidemic in Puerto Rico reached a confrontational climax regarding aerial fumigation with an organophosphate insecticide. The public drama has obscured multiple simultaneous controversies. This and a companion paper, based mostly on print and digital news reports, provide a context and description of the major controversies and examine the outcomes and their lessons for the protection of the public's health. Part I describes the social and sanitary environment, the first three months of the epidemic, and the debates related to religious, demographic, economic, political, and health care concerns.

Zika in Puerto Rico, 2016-2017: II Perspectives on Epidemic Surveillance and Control, Health Communication, Outcomes and Lessons

The social reaction to the Zika epidemic in Puerto Rico reached a confrontational climax regarding aerial fumigation with an organophosphate insecticide. The public drama has obscured multiple simultaneous controversies. This and a companion paper, based mostly on print and digital news reports, provide a context and description of the major controversies and examine the outcomes and their lessons for the protection of the public's health. Part II covers the questions on disease surveillance (what is going on?); health communication and epidemic control (what is an epidemic? is there a way to control an epidemic transmitted by Aedes aegypti?), and the outcomes and lessons from the debates.

Community-acquired acute meningitis and encephalitis: a narrative review

Meningitis and encephalitis are medical emergencies. Patients need prompt evaluation and immediate empiric therapy to reduce the likelihood of fatal outcomes and chronic neurological sequelae. Conjugate bacterial vaccines have significantly reduced the incidence of bacterial meningitis, especially in children. As the results of changes in patterns of bacterial drug sensitivity, ceftriaxone is now part of the recommended empiric treatment for bacterial meningitis and should be administered as early as possible. Neuroimaging delays the treatment of meningitis and is not needed in most cases. Adjunctive corticosteroid therapy is of benefit for many patients with meningitis and should be initiated in most adults before antibiotic therapy. Molecular testing can assist the specific diagnosis of encephalitis and should be based on the exposure history and geographic risk factors relevant to the patient, but non-infectious causes of encephalitis are also common. Empiric therapy for encephalitis should be directed at the most frequently identified infectious pathogen, herpes simplex virus type 1 (ie, intravenous aciclovir). Vaccines can protect against the major pathogens of childhood infections (measles, mumps, rubella, polio, varicella viruses), influenza viruses, and exotic pathogens that cause meningitis and encephalitis (rabies, Japanese encephalitis, dengue, yellow fever, tick-borne encephalitis viruses, Mycobacterium tuberculosis).

[Confirmed Dengue, Chikungunya and Zika Cases during the Period 2014 to 2016 in Barcelona, Spain]

OBJECTIVE

Arbovirus infections are a group of diseases whose incidence is increasing and that entail an important problem for public health. The aim of this study was to describe detected cases of arbovirosis in Barcelona, and surveillance and control actions performed in order to reduce the risk of transmission.

METHODS

Descriptive cross-sectional study of confirmed dengue, chikungunya and Zika cases in Barcelona during 2014-2016 (1st trimester). Suspected cases detected in the city were notified to the Epidemiology Department of the Barcelona Public Health Agency, where an epidemiological survey is undertaken and, if appropriate, Urban Pests Surveillance and Control Department is contacted. They perform an entomological inspection and implement control and monitoring actions. We collected sociodemographical, epidemiological, clinical and entomological variables.

RESULTS

In 2014, 50 chikungunya and 20 dengue cases were detected; 25 entomological inspections were carried out in residences and 38 in the street. In 2015, 47 chikungunya, 51 dengue and 2 Zika cases were detected; 27 inspections were carried out in residences and 80 in the street. In 2016, 17 chikungunya, 52 dengue and 48 Zika cases were detected; 50 inspections were carried out in residences and 103 in the street. No autochtonous case was detected.

CONCLUSIONS

We observed an increasing incidence of arbovirosis cases during the 3-year study period. There was a progressive intensification of vector surveillance and control actions (inspections, sample collection…).

[Zika virus and their means of delivery, rather than Aedes]

In the present work an exposition of the most frequent vectors of the arboviruses is made highlighting the ones of the genus Aedes, of these in each geographic distribution there are specific subgeneros, in Africa emphasizes A. africanus, A. opok and A. vitatus like those in charge of The propagation of arboviruses. In Asia and Oceania, A. hensilii and A. polynesiensis stand out, and A. albopictus, in addition to A. koreicus and A. japonicus, the latter also responsible for dissemination in North America. It is mentioned in the wave that struck to South America the greater importance of other genera like Culex, emphasizing C. pipiens, C. perfuscus, C. quinquefasciatus and C. nigripalpus; Also genera like Anopheles emphasizing A. coustani, A. albimanus and A. pseudopunctipennis (Central America and Mexico). Therefore the importance of other vectors other than Aedes as the participants in the American wave is pointed out.

[Zika, a neurotropic virus?]

In this paper, the neurotropism potential Zika virus is discussed, by comparison with viruses both RNA and DNA are neurotropic known, also it is said that compared with the new viruses that have affected the Americas, as the chikungunya, Zika has shown great affinity by brain tissue, manifested by a high incidence of acute neurological conditions, such as Guillain-Barré syndrome, among others, as well as the reported incidence of microcephaly that is abnormally high compared with the previous incidence, which, in a stillborn subject necropsied significant alterations demonstrated in brain tissue, identifying viral material and live virus in the fetoplacental complex, and demonstrating the impact both white matter and gray matter as well as basal ganglia, corpus callosum, ventricles and spinal cord, which could explain the microcephaly that concerns him. Although not a direct cause-effect relationship is demonstrated, however current evidence supports that relationship, hoping to be supported scientifically.

[Clinical features of Zika virus]

BACKGROUND

Zika virus was introduced to the country and threatens to spread, so the health personnel must be able to identify the disease and face an operational definition given case; in this review the clinical manifestations of probable cases of Zika of the last five years were described.

METHODS

A search was performed in Google Scholar and PubMed with "Zika". He settled for a database and obtained simple frequencies and calculated the limits for proportions with an alpha of 0.05 through test Wilson.

RESULTS

109 probable cases of fever came together by Zika, the clinical manifestations was heterogeneous, with predominant involvement to musculoskeletal, dermatological and systemic level.

CONCLUSIONS

It is necessary to continue the documentation of the clinical manifestations of Zika virus, which will be achieved by strengthening epidemiological surveillance.

[Technical guidelines for the prevention, diagnosis and treatment of Zika virus infection]

Infection Zika virus is an emerging disease in the Americas region, which is caused by Zika virus (ZIKV), an arbovirus of the flavivirus genus. The ZIKV is transmitted by the bite of Aedes mosquitoes, both in urban and jungle area. After the mosquito bite, the disease symptoms usually appear after an incubation period of three to twelve days. The infection may be asymptomatic or presented with fever and not purulent conjunctivitis, headache, myalgia, arthralgia, asthenia, maculopapular rash, edema in lower limbs and, less frequently, retro-orbital pain, anorexia, vomiting, diarrhea or pain abdominal. Symptoms last for 4-7 days and are self-limiting. Neurological and autoimmune complications are rare. Since 2014 it has been detected native circulation of Zika virus in the Americas. So far, there is no specific antiviral treatment or effective vaccine, so it's giving priority symptomatic and supportive treatment for the acute phase and make an early diagnosis of atypical and severe forms.