Incidence and transmission patterns of tuberculosis among indigenous populations in Brazil

Abstract

Approximately 10% of the Brazilian indigenous population lives in the state of Mato Grosso do Sul (MS), where a large number of new cases of tuberculosis (TB) are reported. This study was conducted to assess TB occurrence, transmission and the utility of TB diagnosis based on the Ogawa-Kudoh (O-K) culture method in this remote population. The incidence of TB was estimated by a retrospective review of the surveillance data maintained by the Notifiable Diseases Surveillance System for the study region. The TB transmission pattern among indigenous people was assessed by genotyping Mycobacterium tuberculosis isolates using the IS 6110 restriction fragment length polymorphism (RFLP) technique. Of the 3,093 cases identified from 1999-2001, 610 (~20%) were indigenous patients (average incidence: 377/100,000/year). The use of the O-K culture method increased the number of diagnosed cases by 34.1%. Of the genotyped isolates from 52 indigenous patients, 33 (63.5%) belonged to cluster RFLP patterns, indicating recently transmitted TB. These results demonstrate high, on-going TB transmission rates among the indigenous people of MS and indicate that new efforts are needed to disrupt these current transmissions.

Magnitude da tuberculose pulmonar na população fronteiriça de Mato Grosso do Sul (Brasil), Paraguai e Bolívia

“…Verifica-se taxa de incidência 6,7 vezes maior do que entre os não indígenas, havendo associação significativa entre ser indígena e ter tuberculose pulmonar, corroborando os achados de Cunha et al 20 com base na genotipagem de Mycobacterium tuberculosis. Esses autores constataram elevada taxa de transmissão recente nessa população e vín-culo epidemiológico estabelecido entre 30% dos casos, confirmando a propagação interpessoal da doença.…”

Hypothesis testing clarifies the systematics of the main Central American Chagas disease vector, Triatoma dimidiata (Latreille, 1811), across its geographic range

“…An ~ 500 base pair (bp) fragment of nuclear ITS-2 was amplified using a forward primer annealing in the conserved 5.8S rDNA gene (“5.8T” 5′-CTAAGCGGTGGATCACTCGG-3′) (Marcilla et al, 2001) and our recently described reverse primer annealing in the conserved 28S rDNA gene (“ITS2200R” 5′-CTCGCAGCTACTAAGGGAATCC-3′) using amplification conditions as described (Richards et al, 2013). Alternatively, to obtain just the ITS-2 proposed subspecies, for 99 of the 116 T. dimidiata for which we sequenced the cyt b gene, we amplified the 3′-most ~200 bp of ITS-2 using the ITS2-200 primers (Richards et al, 2013).…”

“…Alternatively, to obtain just the ITS-2 proposed subspecies, for 99 of the 116 T. dimidiata for which we sequenced the cyt b gene, we amplified the 3′-most ~200 bp of ITS-2 using the ITS2-200 primers (Richards et al, 2013). …”

Plasmodium P47 : a key gene for malaria transmission by mosquito vectors

“…Furthermore, Pfs47 is one of the P. falciparum genes with the highest SNP differentiation between Africa, Asia and Oceania (based on whole genome population genetic analysis of 227 isolates) [41]. P. vivax P47 ( Pvs47 ) is also polymorphic [42], and is one of the genes with the highest population differentiation between continents (based on whole genome sequences of 195 isolates) [43]. Analysis of 516 Cambodian isolates detected 22 different Pfs47 protein haplotypes closely-related to all other Asian isolates [44], in agreement with clustering of certain haplotypes in different continents.…”