From what I can tell the Java and NodeJS integration for kafka support distributed tracing:

https://docs.datadoghq.com/tracing/setup_overview/compatibility_requirements/java/#networking-framework-compatibility

Datadog’s Kafka integration works with Kafka version 0.11+, which supports the Header API. This API is used to inject and extract trace context.

https://github.com/DataDog/dd-trace-js/blob/master/packages/datadog-plugin-kafkajs/src/index.js#L64

Is this a wanted feature and doable? If yes I could try to craft a PR with some guidance.