Tuberculosis transmission among children and adolescents in schools and other congregate settings: a systematic review.

Children, especially those aged <5 years, and adolescents are at increased risk of progression to active TB disease when infected. Management of childhood TB outbreaks is crucial for TB elimination especially in low burden countries. We searched the electronic databases MEDLINE-CINHAL-EMBASE up to July 2017 for primary studies reporting on TB incidents which involved teacher/child-caregiver, relative or students diagnosed with TB in a school/childcare setting or in other congregate settings attended by children and adolescents. Out of 10,481 citations, 74 studies, published mostly in low TB burden countries from 1950 to 2017, describing 128 incident investigations, were included. Overall 5025 (14.2%) LTBI and 811 (2.3%) TB cases were diagnosed among 35,331 screened individuals. Incidents occurred mainly in schools (89.1%) where index cases were more frequently students (63.3%) than teachers/caregivers; almost all of the incidents exposing children aged 2-5 were attributable to a teacher/caregiver index case. In 68 individual contact investigations the pooled proportions of TB and LTBI among those exposed were 0.03 (95%CI 0.02-0.04) and 0.15 (95%CI 0.13- 0.18). The overall risk of developing TB disease in school-congregate settings seems slightly lower than in high-income country household settings. Public health interventions targeting school-congregate settings may be critical to overall TB control and towards TB elimination in low-burden countries.

Active Tuberculosis Case Finding Interventions Among Immigrants, Refugees and Asylum Seekers in Italy.

In Italy tuberculosis (TB) is largely concentrated in vulnerable groups such as migrants and in urban settings. We analyzed three TB case finding interventions conducted at primary centers and mobile clinics for regular/irregular immigrants and refugees/asylum seekers performed over a four-year period (November 2009-March 2014) at five different sites in Rome and one site in Milan, Italy. TB history and presence of symptoms suggestive of active TB were investigated by verbal screening through a structured questionnaire in migrants presenting for any medical condition to out-patient and mobile clinics. Individuals reporting TB history or symptoms were referred to a TB clinic for diagnostic workup. Among 6347 migrants enrolled, 891 (14.0%) reported TB history or symptoms suggestive of active TB and 546 (61.3%) were referred to the TB clinic. Of them, 254 (46.5%) did not present for diagnostic evaluation. TB was diagnosed in 11 individuals representing 0.17% of those screened and 3.76% of those evaluated. The overall yield of this intervention was in the range reported for other TB screening programs for migrants, although we recorded an unsatisfactory adherence to diagnostic workup. Possible advantages of this intervention include low cost and reduced burden of medical procedures for the screened population.

Tuberculosis transmission from healthcare workers to patients and co-workers: a systematic literature review and meta-analysis.

Healthcare workers (HCWs) are at risk of becoming infected with tuberculosis (TB), and potentially of being infectious themselves when they are ill. To assess the magnitude of healthcare-associated TB (HCA-TB) transmission from HCWs to patients and colleagues, we searched three electronic databases up to February 2014 to select primary studies on HCA-TB incidents in which a HCW was the index case and possibly exposed patients and co-workers were screened.We identified 34 studies out of 2,714 citations. In 29 individual investigations, active TB was diagnosed in 3/6,080 (0.05%) infants, 18/3,167 (0.57%) children, 1/3,600 (0.03%) adult patients and 0/2,407 HCWs. The quantitative analysis of 28 individual reports showed that combined proportions of active TB among exposed individuals were: 0.11% (95% CI 0.04-0.21) for infants, 0.38% (95% CI 0.01-1.60) for children, 0.09% (95% CI 0.02-0.22) for adults and 0.00% (95% CI 0.00-0.38) for HCWs. Combined proportions of individuals who acquired TB infection were: 0.57% (95% CI 7.28E-03 - 2.02) for infants, 0.9% (95% CI 0.40-1.60) for children, 4.32% (95% CI 1.43-8.67) for adults and 2.62% (95% CI 1.05-4.88) for HCWs. The risk of TB transmission from HCWs appears to be lower than that recorded in other settings or in the healthcare setting when the index case is not a HCW. To provide a firm evidence base for the screening strategies, more and better information is needed on the infectivity of the source cases, the actual exposure level of screened contacts, and the environmental characteristics of the healthcare setting.

Tuberculosis transmission between foreign- and native-born populations in the EU/EEA: a systematic review.

Tuberculosis (TB) control programmes of many low TB incidence countries of the European Union/European Economic Area (EU/EEA) perceive challenges in controlling TB due to high numbers of TB in migrants from high-incidence countries. To assess the extent of TB transmission from the foreign-born to the native-born population, we quantitatively investigated the dynamics of TB transmission between these populations in the EU/EEA, using published molecular epidemiological studies. We searched PubMed and EMBASE databases from 1990 to August 2012. We identified 15 studies performed during 1992-2007 covering 12,366 cases, of which median (range) 49.2% (17.7%-86.4%) were foreign-born. The proportion of clustered isolates ranged between 8.5% and 49.1% of the total number of TB cases genotyped and among these, foreign-born cases were equally or more likely to have unique isolates compared to native-born cases. One third of the clusters were "mixed", i.e. composed of foreign- and native-born cases, involving 0-34.2% of all genotyped cases. Cross-transmission among foreign and native populations was bidirectional, with wide differences across studies. This systematic review provides evidence that TB in a foreign-born population does not have a significant influence on TB in the native population in EU/EEA.

Accuracy of indirect haemagglutination and western blot assays for the detection of anti-Schistosoma antibodies in non-severe febrile patients in two Tanzanian hospitals.

BACKGROUND: The diagnosis of schistosomiasis is usually based on clinical data associated with the detection of eggs in stool, urine, and/or rectal and bladder biopsy specimens. However antibody detection can be useful to indicate Schistosoma infection in those for whom eggs cannot be demonstrated. The aim of this study was to assess the seroprevalence of schistosomiasis and to evaluate the accuracy of indirect haemagglutination (IHA) and Western blot (WB) assays for the detection of anti-Schistosoma antibodies in 2 peripheral hospitals of the United Republic of Tanzania. METHODS: Between February and March 2007 blood samples were collected from 297 non-severe febrile outpatients who attended Chake Chake Hospital, Pemba Island and Tosamaganga Hospital, Iringa region in Tanzania. The samples were processed for Schistosoma antibodies by IHA and WB assays in Italy. RESULTS: Two hundred and sixty-two of 297 patients were schistosomiasis antibody-positive by IHA (88.2%). Of 142 patients positive by IHA, only 22 (12.4%) cases were confirmed by WB assay. The WB assay confirmed all 35 negative cases previously identified by IHA. The seroprevalence of Schistosoma at Chake Chake Hospital was lower than in Tosamaganga Hospital (9/97, 9.3% vs 13/80, 16.2%). CONCLUSIONS: Schistosomiasis is endemic in Tanzania, being more prevalent on the mainland than on Pemba Island. The implications of this study are of public health relevance and suggest the need for increased efforts in large-scale chemotherapy-based morbidity control programmes, integrated with those for other soil-transmitted helminthiases, in these 2 peripheral areas of the United Republic of Tanzania.

Seroprevalence of dengue infection: a cross-sectional survey in mainland Tanzania and on Pemba Island, Zanzibar.

OBJECTIVE: Evidence available to date indicates that dengue viruses 1, 2, and 3 could be among the causes of acute fever in eastern Africa. Recently, four reports on dengue infection in travelers and residents have raised concerns over the occurrence of dengue fever in mainland Tanzania and in Zanzibar. The objective of this study was to provide seroprevalence data on dengue infection in Tanzania. METHODS: This study was conducted in 2007 at two peripheral hospitals, one on Pemba Island, Zanzibar and one in Tosamaganga, Iringa Region, mainland Tanzania. Two hundred and two consecutive febrile outpatients were studied for antibodies and viral RNA to assess the circulation of dengue virus in Tanzania. RESULTS: A seroprevalence of 7.7% was found on Pemba Island and of 1.8% was found in Tosamaganga. No acute cases and no previous infections among patients under 11 years of age were detected. CONCLUSION: These findings provide the first baseline data on dengue seroprevalence in the country. No recent dengue virus circulation in Tanzania and in the Zanzibar archipelago up until the early 1990s is reported.