The Amazonian Tropical Bites Research Initiative, a hope for resolving zoonotic neglected tropical diseases in the One Health era

BACKGROUND

Neglected tropical diseases (NTDs) disproportionately affect populations living in resource-limited settings. In the Amazon basin, substantial numbers of NTDs are zoonotic, transmitted by vertebrate (dogs, bats, snakes) and invertebrate species (sand flies and triatomine insects). However, no dedicated consortia exist to find commonalities in the risk factors for or mitigations against bite-associated NTDs such as rabies, snake envenoming, Chagas disease and leishmaniasis in the region. The rapid expansion of COVID-19 has further reduced resources for NTDs, exacerbated health inequality and reiterated the need to raise awareness of NTDs related to bites.

METHODS

The nine countries that make up the Amazon basin have been considered (Bolivia, Brazil, Colombia, Ecuador, French Guiana, Guyana, Peru, Surinam and Venezuela) in the formation of a new network.

RESULTS

The Amazonian Tropical Bites Research Initiative (ATBRI) has been created, with the aim of creating transdisciplinary solutions to the problem of animal bites leading to disease in Amazonian communities. The ATBRI seeks to unify the currently disjointed approach to the control of bite-related neglected zoonoses across Latin America.

CONCLUSIONS

The coordination of different sectors and inclusion of all stakeholders will advance this field and generate evidence for policy-making, promoting governance and linkage across a One Health arena.

Assessment of crab fishermen's exposure to rabies virus in a typical Amazonian community

Outbreaks of human rabies transmitted by hematophagous bats occurred in 2018 in Pará state, Brazil, eastern Amazon, after 12 years of no record of the disease. Thus, it is necessary to understand the epidemiological characteristics of these attacks to protect the local population. This study aimed to characterize the bat bite populations in the municipality of São João da Ponta, Pará State, Brazil, in 2013-2015. The Notifiable Diseases Information System (SINAN) database was used to identify the five individuals who sought medical care during the study period (seeds). Other individuals who were attacked during the same period but did not seek medical care (n = 61) were reached by snowball sampling, and a descriptive analysis was performed based on information obtained from questionnaires. Majority of the interviewees were men (92.4%; 61/66) and adults aged 20-50 years (69.9%; 46/66) and had <4 years of formal school education (86.3%; 57/66). Additionally, most of them were rural residents (92.4%; 61/66) and crab fishermen (79.3%; 53/66). The interviewees (92.4%; 61/66) identified mangroves of the Mãe Grande de Curuçá extractive reserve, where groups of fishermen sometimes gather for several days for crab fishing, often living in improvised dwellings without walls and covered by tarps or straw (88.8%; 56/66), conducive to attacks by vampire bats. Overall, 42.4% (28/66) of the participants had been bitten more than four times throughout their life. The median number of attacks over the participant's lifetime was 3.11 (range, 1-23). Participants were unaware of the risk of contracting rabies from the bite (95.4%; 65/66). These results suggest that vampire bat attacks are essentially an occupational hazard in the study region. Moreover, for each reported attack, there were at least 12.2 unreported cases. Thus, the study highlights the need to develop strategies for prophylactic treatment of this population.

Serological prevalence of Toxoplasma gondii infection in cats (Belém, Pará, Brazil)

We evaluated the prevalence of anti-Toxoplasma gondii antibodies in the serum samples collected from domestic cats in Belém, Pará, Brazil. We also correlated the presence of T. gondii antibodies with environmental variables and cat-owner habits. Four-hundred and forty-seven serum samples from domestic cats were analyzed. The sera were tested using an indirect immunofluorescence assay. Among the animals analyzed, 21.92% (98/447) were seropositive. A statistically significant association was found in relation to age and serology among the animals over 1 year old (p<0.01): in the group up to 1 year old, 12.82% (20/156) of the animals were positive, and in the group over 1 year old, 26.80% (78/291) were positive. Our results show that the cats in Belém, Pará region have anti-T. gondii antibodies, and their owners are not aware of toxoplasmosis or how to prevent its transmission.

Epidemiological scenarios for human rabies exposure notified in Colombia during ten years: A challenge to implement surveillance actions with a differential approach on vulnerable populations

Based on notified cases of human rabies exposure and human deaths by rabies to Colombia public health surveillance system between 2007 and 2016, we conducted a spatiotemporal analysis to identify epidemiological scenarios of high human rabies exposure due to dogs, cats, bats, or farm animals (n = 666,411 cases). The incidence rate of human rabies exposures was analyzed by using geographical information system (spatiotemporal distribution and Cluster and Outlier Analysis (Anselin Local Moran's I)) data for all Colombian cities. The incidence rate of human rabies exposures due to dogs and cats showed an increasing trend, while aggression due bats and farm animals fluctuated throughout the analyzed period. Human deaths by rabies transmitted by cat and bat occurred in the Andean and Orinoquia regions, which had urban and rural scenarios. The urban scenario showed the highest exposure to human rabies due to cats and dogs in cities characterized with high human population density and greater economic development. In contrary, the highest human rabies exposure in the rural scenario was observed due to contact of mucosa or injured skin with the infected saliva of farm animals with the rabies virus, principally among workers in the agroforestry area. The inequality scenario showed some outlier cities with high human rabies exposure due to farm animals principally in the Pacific region (characterized by the highest poverty rates in Colombia), being Afro-descendant and indigenous population the most exposed. The highest exposure due to bats bite was observed among indigenous people residing in cities of the Amazon region as a dispersed population (Amazonian scenario). None of the high exposure scenarios were related to human deaths by rabies due to dogs aggression. The identified scenarios can help develop better surveillance systems with a differential approach to the vulnerable population and strengthening them in areas with rabies viral circulation.

Characterization of rabies post-exposure prophylaxis in a region of the eastern Amazon, state of Pará, Brazil, between 2000 and 2014

Animal bites are a serious public health issue, and prevention strategies have been consistently documented worldwide. The aim of this study was to characterize human anti-rabies treatment in 11 counties of the Salgado microregion, Pará state, Brazil, which borders the Bragantina microregion, where exposures of human rabies were reported in 2004 and 2005. A descriptive retrospective study was conducted using anti-rabies treatment notifications registered in the Information System for Notifiable Diseases (SINAN) database of the State Department of Public Health of Pará (SESPA) from January 2000 to December 2014. In this period, 13,403 exposures were reported, with a growing annual trend (Y = 68.571x + 344.96). The years 2012 and 2013 presented the highest exposure incidence. Salinópolis was the county with the highest average annual incidence per 10,000 persons (62.83), followed by São João de Pirabas (43.28) and São Caetano de Odivelas (41.27). Most patients were males (59.6%) and were 1-19 years old (48.7%). The main species involved in aggressions were dogs (74.1%), followed by bats (13.1%) and cats (7.4%). Biting was the most common kind of exposure, mostly on the lower limbs (39.6%). This study shows that aggression by bats was the second most common cause of demand for the service in the region for the past 14 years. The low quality of records may increase the difficulty of rabies surveillance in Pará.

ATIVIDADE ACARICIDA DE Nicotiana tabacum SOBRE OVOS DE Rhipicephalus (Boophilus) microplus

A utilização de acaricidas sintéticos é a forma mais comum para o controle do carrapato-do-boi, Rhipicephalus (Boophilus) microplus. Porém, os problemas acarretados pelo o uso indiscriminado desses produtos têm impulsionado a busca por métodos alternativos como a utilização de compostos a base de plantas medicinais. Nesse contexto, este estudo objetivou avaliar a eficácia de diferentes métodos de extração do fumo de corda (Nicotiana tabacum) contra ovos de R. microplus. Para a obtenção dos extratos da planta, foram utilizadas as seguintes técnicas: maceração, destilação e extração de Soxhlet, todas utilizando a água como solvente. Os ovos foram organizados em alíquotas de 100 mg para serem tratados com os extratos e, posteriormente, observados diariamente para o registro dos parâmetros relativos à eclosão larval. Observou-se um aumento significativo no período de incubação quando foram utilizados os extratos obtidos por maceração ou Soxhlet. O período e o percentual de eclosão foram significativamente reduzidos, com a utilização de qualquer uma das técnicas de extração. Portanto, o extrato aquoso de N. tabacum, sem a necessidade de formulações, é eficaz para impedir a eclodibilidade larval sob as condições empregadas nesta pesquisa.

Artificial feeding of Amblyomma cajennense (Acari: Ixodidae) fasting females through capillary tube technique

The present study aimed to adjust the artificial feeding technique through capillaries and to verify its influence over the biology of Amblyomma cajennense females. Five groups of 20 female ticks were formed. Females were starved for 45 days and then fed with citrated bovine blood using capillary tubes in different periods of time. Females were divided in five experimental groups with 20 individuals each and fed as follows: groups uninterruptedly fed for 12, 24, and 48 hours and groups fed 2 and 6 h a day, for a period of 8 days. Subsequently, ticks were exposed to rabbits for complementary feeding and their biological parameters were analyzed. TIcks were capable of feeding, showing rounded idiosoma, visible even to naked eyes, following the feeding period. The groups fed for 24 hours, 2 hours/day for eight consecutive days or 6h/day for eight consecutive days presented greater weight gain, without statistically significant differences. These results suggested that 24 hours of artificial feeding were enough for fasting females to increase weight by 2.43 mg. Artificial feeding through capillaries did not interfere with parasitic and non-parasitic phases of A. cajennense females.

AMBLYOMMA TIGRINUM KOCH, 1844 (ACARI: IXODIDAE) EM CÃES DOMÉSTICOS PROCEDENTES DA RESERVA FLORESTAL DO BOQUEIRÃO, MUNICÍPIO DE INGAÍ, SUL DE MINAS GERAIS

RESUMO A ocorrência de Amblyomma tigrinum parasitando cães domésticos é registrada pela primeira vez na região sul de Minas Gerais. Foi observada ainda, coinfestação dessa espécie com A aureolatum, o que alerta para a possilbidade de transmissão de patógenos silvestres para humanos.

[Electrostimulation of the pelvic floor muscles in urinary incontinence]

External electrical stimulation is a simple, noninvasive and inexpensive treatment modality, which is useful in the treatment of stress- and/or idiopathic urge incontinence. The mode of action arises from excitation of the pudendal nerves leading to direct and reflex contraction of pelvic floor muscles and a reflex inhibition of the detrusor. Treatment can be applied either as a weak long-term stimulation at home, as a short-term maximal stimulation in clinic, hospital or home treatment. Approximately 50%-75% of incontinent patients are either cured or improved and the adverse effects are sparse. Electrostimulation seems to be valuable in the treatment of incontinence.

Supravital dithizone staining in the isolation of human and rat pancreatic islets

Dithizone, a zinc chelating agent, is known to selectively stain the islets of Langerhans in the pancreas. In the present study, we have used this stain to aid the identification of islets in material obtained by collagenase digestion of human pancreas. Islets were shown to rapidly and reversibly stain red on incubation with dithizone solution. Tissue selected on the basis of dithizone staining was shown to contain insulin-positive cells and to accumulate insulin in the medium during a subsequent period in tissue culture. Experiments with rat islets indicated that the dithizone treatment had no effect on insulin release in tissue culture, on acute responses to stimulatory glucose concentrations or on the insulin content of cells. These results suggest that dithizone staining can assist in the identification of islets from the human pancreas and may prove to be a useful tool in developing techniques for the large scale isolation of functionally intact human islets.