[Epidemiological pattern of lymphatic filariasis in children living in endemic areas]

Lymphatic Filariasis: A Systematic Review on Morbidity and Its Repercussions in Countries in the Americas

The Global Program to Eliminate Lymphatic Filariasis (GPELF) is a program that aims to eliminate lymphatic filariasis by 2030. The GPELF strategy is based on interrupting transmission using mass drug administration (MDA) and, in parallel, managing morbidity cases. However, it has been seen that there is a shortage of research in the literature and public policies regarding this last pillar. In this study, we reviewed the literature and available information regarding the burden of filarial morbidity. In addition, we identified that in the Americas, the implementation of structured services with regard to morbidity assistance in the Americas was scarce. We formed a review that aimed to assess the pathogenesis, epidemiology, repercussions, and treatment of filarial morbidity in countries in the Americas where lymphatic filariasis is endemic. Structured searches were carried out on PubMed, LILACS, Scopus, and Web of Science databases without time and language restrictions. Three reviewers evaluated the 2150 studies and performed data extraction, and quality assessment by assigning scores to the studies found. The current literature and available information on the burden of filarial morbidity, as well as the implementation of structured services with regard to morbidity assistance in the Americas, were all found to be scarce. Now that this knowledge gap has been identified, both health services and researchers need to seek the implementation and enhancement of the maintenance of GPELF strategies that relate to the morbidity pillar.

Microcephaly epidemic related to the Zika virus and living conditions in Recife, Northeast Brazil

Background

Starting in August 2015, there was an increase in the number of cases of neonatal microcephaly in Northeast Brazil. These findings were identified as being an epidemic of microcephaly related to Zika virus (ZIKV) infection. The present study aims to analyse the spatial distribution of microcephaly cases in Recife (2015–2016), which is in Northeast Brazil, and its association with the living conditions in this city.

Methods

This was an ecological study that used data from reported cases of microcephaly from the State Health Department of Pernambuco (August 2015 to July 2016). The basic spatial unit of analysis was the 94 districts of Recife. The case definition of microcephaly was: neonates with a head circumference of less than the cut-off point of −2 standard deviations below the mean value from the established Fenton growth curve. As an indicator of the living conditions of the 94 districts, the percentage of heads of households with an income of less than twice the minimum wage was calculated. The districts were classified into four homogeneous strata using the K-means clustering algorithm. We plotted the locations of each microcephaly case over a layer of living conditions.

Results

During the study period, 347 microcephaly cases were reported, of which 142 (40.9%) fulfilled the definition of a microcephaly case. Stratification of the 94 districts resulted in the identification of four strata. The highest stratum in relation to the living conditions presented the lowest prevalence rate of microcephaly, and the overall difference between this rate and the rates of the other strata was statistically significant. The results of the Kruskal-Wallis test demonstrated that there was a strong association between a higher prevalence of microcephaly and poor living conditions. After the first 6 months of the study period, there were no microcephaly cases recorded within the population living in the richest socio-economic strata.

Conclusion

This study showed that those residing in areas with precarious living conditions had a higher prevalence of microcephaly compared with populations with better living conditions.

Lymphatic filariasis among children and adolescents: spatial identification via socio-environmental indicators to define priority areas for elimination

BACKGROUND

The occurrence of lymphatic filariasis (LF) and its transmission dynamics among children and adolescents are still not clearly elucidated. The aim of this study was to describe the spatial distribution of microfilaremia and its relationship with socio-environmental variables, thereby identifying areas at greater risk of transmission.

METHODS

An ecological study was conducted, in which the analysis unit was formed by districts of the municipality of Jaboatão dos Guararapes in the state of Pernambuco, Brazil. The data source was a parasitological survey. Inadequate sewage disposal, number of people in the household and income of between 0.5 and 1 minimum salary were used to construct the socio-environmental indicator. The districts were then grouped according to the indicator into three risk strata, using the k-means clustering technique.

RESULTS

In the study, 96/8670 (1.1%) of the population were found to present microfilaremia. The high-risk stratum had a mean prevalence rate of 1.9% and a risk of 2.56 (p<0.05), in relation to the low-risk stratum. The middle stratum grouped the households that presented an intermediate risk of transmission, with a prevalence rate of 1.92%.

CONCLUSIONS

The indicator used is a promising tool that enables the precise measurement of the relationship between social deprivation and the prevalence of filarial infection among children. Thus, it can be used to plan control and elimination actions.

Prevalence and risk factors for scrotal lesions/anomalies in a cohort of Brazilian men ≥ 40 years of age

OBJECTIVE

To estimate the prevalence of and risk factors for cutaneous lesions of the scrotum and intrascrotal lesions/anomalies among men included in a prostatic cancer screening program in a Brazilian metropolitan city.

DESIGN AND SETTING

Cross-sectional study, private outpatient healthcare service.

METHODS

1731 men aged 40 years or over, participating in a prostate cancer screening program conducted by the municipal public employees' healthcare system, underwent systematic urological assessment by a single examiner.

RESULTS

The prevalence of scrotal diseases in our sample was 44.7% (773/1731). Tinea cruris occurred in 203 (11.7%) of the participants, with higher risk among diabetics and lower prevalence among nonwhite individuals; scrotal tinea in eight (0.5%), with higher risk among hypertensive men; subcutaneous nodules in 12 (0.7%), especially in individuals with low schooling level; hydrocele in 283 (16.4%), with higher frequency among participants over the age of 60 years, diabetics or individuals with previous histories of nonspecific urethritis; spermatoceles in 174 (10.1%), with greater prevalence among individuals over the age of 60 years or diabetics, and lower frequency among individuals who underwent vasectomy; unilateral testicular hypotrophy/atrophy in 167 (9.7%) and bilateral hypotrophy/atrophy in 93 (5.4%), both occurring more frequently in individuals over the age of 60 years; absence of palpable testicles due to cryptorchidism in 7 (0.4%); and epididymitis/orchitis in 5 (0.3%), with higher prevalence among diabetics. No cases of cancer were identified in this sample.

CONCLUSIONS

Scrotal diseases were highly prevalent in this population of Brazilian men.

Lymphatic filariasis in Brazil: epidemiological situation and outlook for elimination

Since the World Health Assembly's (Resolution WHA 50.29, 1997) call for the elimination of lymphatic filariasis by the year 2020, most of the endemic countries identified have established programmes to meet this objective. In 1997, a National Lymphatic Filariasis Elimination Plan was drawn up by the Ministry of Health of Brazil, creating local programs for the elimination of Bancroftian filariasis in areas with active transmission. Based on a comprehensive bibliographic search for available studies and reports of filariasis epidemiology in Brazil, current status of this parasitic infection and the outlook for its elimination in the country were analysed. From 1951 to 1958 a nationwide epidemiological study conducted in Brazil confirmed autochthonous transmission of Bancroftian filariasis in 11 cities of the country. Control measures led to a decline in parasite rates, and in the 1980s only the cities of Belém in the Amazonian region (Northern region) and Recife (Northeastern region) were considered to be endemic. In the 1990s, foci of active transmission of LF were also described in the cities of Maceió, Olinda, Jaboatão dos Guararapes, and Paulista, all in the Northeastern coast of Brazil. Data provide evidence for the absence of microfilaremic subjects and infected mosquitoes in Belém, Salvador and Maceió in the past few years, attesting to the effectiveness of the measures adopted in these cities. Currently, lymphatic filariasis is a public health problem in Brazil only in four cities of the metropolitan Recife region (Northeastern coast). Efforts are being concentrated in these areas, with a view to eliminating the disease in the country.

Mapping of Wuchereria bancrofti infection in children and adolescents in an endemic area of Brazil

A parasitological survey was conducted among children and adolescents in the municipality of Jaboatão dos Guararapes, Brazil to describe the occurrence and spatial distribution of lymphatic filariasis. Microfilaraemia was investigated through the thick smear technique, using 50 μl of capillary blood that was collected at night. The spatial analysis used a digital base map of the municipality, divided into districts, which were classified as hypoendemic, mesoendemic or hyperendemic. 8670 children were examined and 96 cases of microfilaraemia were identified (1.1%). The prevalence rate did not differ significantly between the sexes. Occurrences of filarial infection increased with increasing age: the greatest prevalence was recorded between 15 and 18 years of age (P<0.05). There were 49 reports of clinical manifestations. The spatial distribution of microfilaraemia according to residential district showed that 13 (54.2%) of the 24 districts investigated were positive. Approximately 33% of the districts were hyperendemic. The results demonstrated that the pediatric population had intense early exposure to the parasite, thus characterizing filariasis as endemic in the municipality. The spatial analysis allowed identification of areas with greater occurrence of infection among children, and showed localities where the populations most exposed to transmission were concentrated. Epidemiological surveillance of microfilaraemia among children and spatial analysis are important local transmission indicators and form instruments for planning actions within the Global Program to Eliminate Lymphatic Filariasis, since they make it possible to identify priority areas.

Bancroftian filariasis in a paediatric population: an ultrasonographic study

Little is known about lymphatic filariasis or the anatomical location of adult Wuchereria bancrofti in children. Seventy-eight children from Greater Recife, 23 microfilaria-positive and 55 microfilaria-negative in approximately 60 microL blood, underwent ultrasound examinations of the major superficial lymphatic vessels of the limbs, scrotal area (boys), and breast area (girls). The characteristic movements of adult worms, known as the filaria dance sign (FDS), were detected in 11 (14.1%) children. In 9 boys, the FDS was detected in lymphatic vessels of the scrotal area (8, ages 14-16) and the inguinal cord (1, age 11). In girls, the FDS was detected in a crural lymphatic vessel and an axillary lymph node. FDS detection was more common in boys (P = 0.06), older children (P = 0.001), and children with microfilaraemia (P = 0.05). Diffuse lymphangiectasia was visualized in 4 boys (ages 14-16) and 2 children had clinical signs of filariasis. These ultrasonographic findings associate W. bancrofti with both infection and disease in children.