Detection and genotyping of human adenovirus and sapovirus in children with acute gastroenteritis in Belém, Pará, between 1990 and 1992: first detection of GI.7 and GV.2 sapoviruses in Brazil

<div><p>Abstract INTRODUCTION: Acute gastroenteritis (AGE) is one of the most common causes of morbidity and mortality, especially among children from developing countries. Human adenovirus (HAdV) and sapovirus (SaV) are among the agents that cause AGE. The present study aimed to detect and genotype HAdV and SaV in 172 fecal samples from children with AGE, collected during a surveillance study carried out in a low-income community in Belém, Pará, between 1990 and 1992. METHODS: HAdV was detected by nested PCR, using primers Hex1deg/Hex2deg and NeHex3deg/NeHex4deg. SaV was assayed by reverse transcription PCR (RT-PCR), nested PCR, and quantitative PCR. The nucleotide sequence was determined by direct cycle sequencing. RESULTS: Overall, 43% (74/172) of samples were positive for HAdV, of which 70.3% (52/74) were sequenced and classified as belonging to five different species, mostly A and F. For SaV, positivity was 5.2% (9/172) and genotypes GI.1, GI.7, GII.1, and GV.2 were detected. CONCLUSIONS: The present results reinforce the need for further studies to obtain epidemiological data about the circulation of these viruses in Brazil, especially in the Amazon Region, where data from the early 1990’s are scarce. Furthermore, the study describes for the first time the detection of SaV genotypes GI.7 and GV.2 in Brazil, showing that these types circulated in the region more than 25 years ago.</p></div

Schematic representation of the distribution of seropositive cases in the couples of families with HTLV-1/HTLV-2.

<p>Source: This image was made exclusively for the paper from data collected in Tropical Medicine Center, Belém, Pará, Brazil.</p

Frequency of positive HTLV-1/HTLV-2 tests in relatives of HTLV carriers from Belém.

<p>Frequency of positive HTLV-1/HTLV-2 tests in relatives of HTLV carriers from Belém.</p

Frequency of positive HTLV-1/HTLV-2 tests in mother-offspring and spouse-spouse dyads of patients from Belém.

<p>Frequency of positive HTLV-1/HTLV-2 tests in mother-offspring and spouse-spouse dyads of patients from Belém.</p

Box-plot comparing the age of the seropositive and seronegative relatives of HTLV-1/HTLV-2 carriers from Belém.

<p>Source: This image was made exclusively for the paper from data collected in Tropical Medicine Center, Belém, Pará, Brazil.* Chi-square test.</p

Low genetic diversity of the Human T-cell Lymphotropic Virus (HTLV-1) in an endemic area of the Brazilian Amazon basin

<div><p>The Human T-cell Lymphotropic Virus (HTLV-1) is a <i>Deltaretrovírus</i> that was first isolated in the 1970s, and associated with Adult T-cell Leucemia-Lymphoma (ATLL), and subsequently to Tropical Spastic Paraparesis-Myelopathy (TSP/HAM). The genetic diversity of the virus varies among geographic regions, although its mutation rate is very low (approximately 1% per thousand years) in comparison with other viruses. The present study determined the genetic diversity of HTLV-1 in the metropolitan region of Belém, in northern Brazil. Blood samples were obtained from patients at the UFPA Tropical Medicine Nucleus between January 2010 and December 2013. The DNA was extracted and the PX region of the HTLV was amplified using nested PCR. The positive samples were then digested using the Taq1 enzyme for the identification and differentiation of the HTLV-1 and HTLV-2. The 5’LTR region of the positive HTLV-1 samples were amplified by nested PCR, and then sequenced genetically. The phylogenetic analysis of the samples was based on the maximum likelihood method and the evolutionary profile was analyzed by the Bayesian approach. Overall, 78 samples tested positive for HTLV-1, and 44 were analyzed here. The aA (cosmopolitan-transcontinental) subtype was recorded in all the samples. The following evolutionary rates were recorded for the different subtypes–a: 2.10−³, b: 2.69. 10−², c: 6.23. 10−², d: 3.08. 10−², e: 6. 10−², f: 1.78. 10−³, g: 2.2. 10−² mutations per site per year. The positive HTLV-1 samples tested in the present study were characterized by their low genetic diversity and high degree of stability.</p></div

Phylogenetic analysis of the 744 bps nucleotide sequence corresponding to the 5’LTR region of the HTLV-1, based on the maximum likelihood method with 10,000 bootstrap replicates.

<p>The samples analyzed in the present study are shown in red, and all other were obtained from GenBank (<a href="https://www.ncbi.nlm.nih.gov/genbank" target="_blank">https://www.ncbi.nlm.nih.gov/genbank</a>).</p