How to implement the framework for the elimination of mother-to-child transmission of HIV, syphilis, hepatitis B and Chagas (EMTCT Plus) in a disperse rural population from the Gran Chaco region: A tailor-made program focused on pregnant women

Estimation of the morbidity and mortality of congenital Chagas disease: A systematic review and meta-analysis

Chagas disease is caused by the parasite Trypanosoma cruzi which can be transmitted from mother to baby during pregnancy. There is no consensus on the proportion of infected infants with clinical signs of congenital Chagas disease (cCD). The objective of this systematic review is to determine the burden of cCD. Articles from journal inception to 2020 reporting morbidity and mortality associated with cCD were retrieved from academic search databases. Observational studies, randomized-control trials, and studies of babies diagnosed with cCD were included. Studies were excluded if they were case reports or series, without original data, case-control without cCD incidence estimates, and/or did not report number of participants. Two reviewers screened articles for inclusion. To determine pooled proportion of infants with cCD with clinical signs, individual clinical signs, and case-fatality, random effects meta-analysis was performed. We identified 4,531 records and reviewed 4,301, including 47 articles in the narrative summary and analysis. Twenty-eight percent of cCD infants showed clinical signs (95% confidence interval (CI) = 19.0%, 38.5%) and 2.2% of infants died (95% CI = 1.3%, 3.5%). The proportion of infected infants with hepatosplenomegaly was 12.5%, preterm birth 6.0%, low birth weight 5.8%, anemia 4.9%, and jaundice 4.7%. Although most studies did not include a comparison group of non-infected infants, the proportion of infants with cCD with clinical signs at birth are comparable to those with congenital toxoplasmosis (10.0%-30.0%) and congenital cytomegalovirus (10.0%-15.0%). We conclude that cCD burden appears significant, but more studies comparing infected mother-infant dyads to non-infected ones are needed to determine an association of this burden to cCD.

Emerging and reemerging forms of Trypanosoma cruzi transmission

This review aims to update and discuss the main challenges in controlling emergent and reemergent forms of Trypanosoma cruzi transmission through organ transplantation, blood products and vertical transmission in endemic and non-endemic areas as well as emergent forms of transmission in endemic countries through contaminated food, currently representing the major cause of acute illness in several countries. As a neglected tropical disease potentially controllable with a major impact on morbimortality and socioeconomic aspects, Chagas disease (CD) was approved at the WHO global plan to interrupt four transmission routes by 2030 (vector/blood transfusion/organ transplant/congenital). Implementation of universal or target screening for CD are highly recommended in blood banks of non-endemic regions; in organ transplants donors in endemic/non-endemic areas as well as in women at risk from endemic areas (reproductive age women/pregnant women-respective babies). Moreover, main challenges for surveillance are the application of molecular methods for identification of infected babies, donor transmitted infection and of live parasites in the food. In addition, the systematic recording of acute/non-acute cases and transmission sources is crucial to establish databases for control and surveillance purposes. Remarkably, antiparasitic treatment of infected reproductive age women and infected babies is essential for the elimination of congenital CD by 2030.

Impact of a public health intervention for active surveillance and mitigation of SARS-CoV-2 in a district from Buenos Aires province, Argentina: a descriptive epidemiological study

BACKGROUND

The first case of SARS-CoV-2 was reported in Argentina on 3 March 2020. Measures to limit the spread of the virus were implemented, including complete lockdown (26 March). Nonetheless, the virus spread throughout the country, with a first peak of almost a million cases in October. On 30 November, the government's recommendation switched from social, preventive and compulsory isolation, to social, preventive and compulsory distancing.

OBJECTIVES

To describe a tailored public health strategy to mitigate the spread of SARS-CoV-2 and determine its behaviour in San Antonio de Areco district from Buenos Aires province (Argentina) through a private-public association.

DESIGN, SETTING AND PARTICIPANTS

Surveillance of the virus was performed with the local healthcare system, through early identification of cases and the systematic study of each infected individual and contact, regardless of symptomatology, using telemedicine and a COVID-19-specific outpatient clinic. Real-time PCR was used for detection using both individual and pooled samples, with a 12-hour turnaround time.

RESULTS

Up to 30 November, a total of 2426 suspected cases were analysed and 578 were confirmed. Surveillance of health personnel and at-risk populations proved effective, mitigating viral spread. Pooling samples allowed reduction of operator time, helped reduce costs, and allowed detection of both symptomatic and asymptomatic cases.

CONCLUSION

After 8 months of protocol implementation, the strategy to intensively survey groups at higher epidemiological risk and the systematic search for asymptomatic cases with the incorporation of pooled PCR for diagnosis, in combination with individual testing, is an efficient and viable option in populations with similar characteristics, in the frame of social isolation.

Screening for Chagas Disease during Pregnancy in the United States-A Literature Review

Obstetrician-gynecologists in the United States have little clinical experience with the epidemiology, pathophysiology, diagnosis, and treatment of Chagas disease. The number of US parturients born in Central and South America has continued to increase over the last 20 years, making US obstetricians more and more likely to care for Chagas-infected mothers who may never be identified until dealing with long-term consequences of the disease. A literature search demonstrates that few US obstetric care providers recognize the risk of vertical transmission for the neonate and the missed opportunity of infant treatment to decrease disease prevalence. Most women will be asymptomatic during pregnancy, as will their neonates, making routine laboratory screening a necessity for the identification of at-risk neonates. While the benefits of treating asymptomatic women identified in pregnancy are not as clear as the benefits for the infants, future health screenings for evidence of the progression of Chagas disease may be beneficial to these families. The literature suggests that screening for Chagas in pregnancy in the US can be done in a cost-effective way. When viewed through an equity lens, this condition disproportionately affects families of lower socioeconomic means. Improved education of healthcare providers and appropriate resources for diagnosis and treatment can improve this disparity in health outcomes.

Congenital Chagas disease: progress toward implementation of pregnancy-based screening

PURPOSE OF REVIEW

Lack of recognition of congenital Chagas disease in infants of mothers from endemic regions who are living in countries nonendemic for Trypanosoma cruzi infection suggests a high rate of underdiagnosis. Pregnancy is the optimal access point for identifying Chagas disease in at-risk mothers and their infants. In this review, we update progress toward implementation of pregnancy-based screening for congenital Chagas disease in nonendemic settings.

RECENT FINDINGS

International organizations have updated recommendations for diagnosis, treatment and prevention of congenital Chagas disease. Reports of successful implementation of pregnancy-based screening at some centers provide a model for optimizing diagnosis of congenital Chagas disease. Screening family members of index patients may identify additional T. cruzi-infected persons. Promising tests to augment current diagnostic modalities for maternal and congenital Chagas disease are in development. Universal or risk-based screening would be cost-effective. More healthcare providers are now aware that treatment of congenital Chagas disease is curative and are promoting efforts to make pregnancy-based screening for congenital Chagas disease a standard of care.

SUMMARY

Ongoing efforts to implement routine pregnancy-based screening for congenital Chagas disease in nonendemic regions will mutually benefit infants, their mothers and family members and can prevent potentially fatal Chagas cardiomyopathy.

Long-term impact of a ten-year intervention program on human and canine Trypanosoma cruzi infection in the Argentine Chaco

BACKGROUND

Interruption of domestic vector-borne transmission of Trypanosoma cruzi is still an unmet goal in several American countries. In 2007 we launched a long-term intervention program aimed to suppress house infestation with the main domestic vector in southern South America (Triatoma infestans) and domestic transmission in Pampa del Indio, a resource-constrained, hyperendemic municipality with 1446 rural houses inhabited by Creole and indigenous people, in the Argentine Chaco ecoregion. Here, we assessed whether the 10-year insecticide-based program combined with community mobilization blocked vector-borne domestic transmission of T. cruzi to humans and dogs.

METHODS

We carried out two municipality-wide, cross-sectional serosurveys of humans and dogs (considered sentinel animals) during 2016-2017 to compare with baseline data. We used a risk-stratified random sampling design to select 273 study houses; 410 people from 180 households and 492 dogs from 151 houses were examined for antibodies to T. cruzi using at least two serological methods.

RESULTS

The seroprevalence of T. cruzi in children aged <16 years was 2.5% in 2017 (i.e., 4- to 11-fold lower than before interventions). The mean annual force of child infection (λ) sharply decreased from 2.18 to 0.34 per 100 person-years in 2017. One of 102 children born after interventions was seropositive for T. cruzi; he had lifetime residence in an apparently uninfested house, no outside travel history, and his mother was T. cruzi-seropositive. No incident case was detected among 114 seronegative people of all ages re-examined serologically. Dog seroprevalence was 3.05%. Among native dogs, λ in 2016 (1.21 per 100 dog-years) was 5 times lower than at program onset. Six native adult dogs born after interventions and with stable lifetime residence were T. cruzi-seropositive: three had exposure to T. infestans at their houses and one was an incident case.

CONCLUSIONS

These results support the interruption of vector-borne transmission of T. cruzi to humans in rural Pampa del Indio. Congenital transmission was the most likely source of the only seropositive child born after interventions. Residual transmission to dogs was likely related to transient infestations and other transmission routes. Sustained vector control supplemented with human chemotherapy can lead to a substantial reduction of Chagas disease transmission in the Argentine Chaco.

Rapid Diagnostic Tests for Trypanosoma cruzi Infection: Field Evaluation of Two Registered Kits in a Region of Endemicity and a Region of Nonendemicity in Argentina

Infection by Trypanosoma cruzi (Chagas disease [ChD]) affects around 7 million people in the Americas, most of whom are unaware of their status due to lack of clinical manifestations and poor access to diagnosis. Rapid diagnostic tests (RDTs) are widely used for screening for different infections (HIV, hepatitis B, and syphilis), and their application for ChD would facilitate access to diagnosis, especially in remote areas where health services have scarce resources. We conducted a prospective intervention study in 2018 to evaluate in the field two in vitro RDTs for ChD, authorized by the National Administration of Medicaments, Aliments, and Medical Technologies of Argentina (ANMAT), in areas of endemicity and nonendemicity in Argentina.

Infection by Trypanosoma cruzi (Chagas disease [ChD]) affects around 7 million people in the Americas, most of whom are unaware of their status due to lack of clinical manifestations and poor access to diagnosis. Rapid diagnostic tests (RDTs) are widely used for screening for different infections (HIV, hepatitis B, and syphilis), and their application for ChD would facilitate access to diagnosis, especially in remote areas where health services have scarce resources. We conducted a prospective intervention study in 2018 to evaluate in the field two in vitro RDTs for ChD, authorized by the National Administration of Medicaments, Aliments, and Medical Technologies of Argentina (ANMAT), in areas of endemicity and nonendemicity in Argentina. We recruited 607 volunteers older than 18 years in Salta province and the city of Buenos Aires. The RDTs Ab Standard Diagnostics SD Bioline (SD) and Check Chagas Wiener Lab (WL) were performed in situ with whole-blood samples, and confirmatory serology was done at a reference center. The rate of infection with T. cruzi was 17.8% (108/607). The SD test showed 97.2% sensitivity (95% confidence interval [CI], 93.5 to 100) and 91.7% specificity (95% CI, 96.2 to 99.2%), and the WL test showed 93.4% sensitivity (95% CI, 88.2 to 98.6%) and 99.1% specificity (95% CI, 91.9 to 100%). The sensitivity and specificity for the two RDTs tested were higher than previously reported. These results encourage the use of the tested RDTs in Salta province and for further field studies for the implementation of these RDTs in other epidemiological scenarios. This will be very important to improve access to diagnosis of Chagas and its clinical management as a neglected disease, especially in remote areas with health access barriers.