Development of a loop-mediated isothermal amplification assay for the detection of Streptococcus agalactiae in bovine milk.

Streptococcus agalactiae is a well-characterized bovine mastitis pathogen that is known to be highly contagious and capable of spreading rapidly in affected dairy herds. Loop-mediated isothermal amplification (LAMP) is a novel molecular diagnostic method that has the capability to provide rapid, cost-effective screening for pathogens to support on-farm disease control and eradication programs. In the current study, a LAMP test was developed to detect S. agalactiae in milk. The assay was validated on a bank of existing clinical mastitis milk samples that had previously been identified as S. agalactiae positive via traditional microbiological culture techniques and PCR. The LAMP assay was conducted on bacterial colonies and DNA extracted from milk in tube- and plate-based formats using multiple detection platforms. The 1-h assay conducted at 64 °C exhibited repeatability (coefficient of variation) of 2.07% (tube) and 8.3% (plate), sensitivity to ~20 pg of extracted DNA/reaction, and specificity against a panel of known bacterial mastitis pathogens. Of the 109 known S. agalactiae isolates assessed by LAMP directly from bacterial cells in culture, 108 were identified as positive, in accordance with PCR analysis. The LAMP analysis from the corresponding milk samples indicated that 104 of these milks exhibited a positive amplification curve. Although exhibiting some limitations, this assay provides an opportunity for rapid screening of milk samples to facilitate on-farm management of this pathogen.

Task-shifting and prioritization: a situational analysis examining the role and experiences of community health workers in Malawi.

BACKGROUND: As low- and middle-income countries face continued shortages of human resources for health and the double burden of infectious and chronic diseases, there is renewed international interest in the potential for community health workers to assume a growing role in strengthening health systems. A growing list of tasks, some of them complex, is being shifted to community health workers' job descriptions. Health Surveillance Assistants (HSAs) - as the community health worker cadre in Malawi is known - play a vital role in providing essential health services and connecting the community with the formal health care sector. The objective of this study was to understand the performed versus documented roles of the HSAs, to examine how tasks were prioritized, and to understand HSAs' perspectives on their roles and responsibilities. METHODS: A situational analysis of the HSA cadre and its contribution to the delivery of health services in Zomba district, Malawi was conducted. Focus groups and interviews were conducted with 70 HSAs. Observations of three HSAs performing duties and work diaries from five HSAs were collected. Lastly, six policy-maker and seven HSA supervisor interviews and a document review were used to further understand the cadre's role and to triangulate collected data. RESULTS: HSAs performed a variety of tasks in addition to those outlined in the job description resulting in issues of overloading, specialization and competing demands existing in the context of task-shifting and prioritization. Not all HSAs were resistant to the expansion of their role despite role confusion and HSAs feeling they lacked adequate training, remuneration and supervision. HSAs also said that increasing workload was making completing their primary duties challenging. Considerations for policy-makers include the division of roles of HSAs in prevention versus curative care; community versus centre-based activities; and the potential specialization of HSAs. CONCLUSION: This study provides insights into HSAs' perceptions of their work, their expanding role and their willingness to change the scope of their practice. There are clear decision points for policy-makers regarding future direction in policy and planning in order to maximize the cadre's effectiveness in addressing the country's health priorities.