Foreword:This July29Day, < /strong>WHOofficial website published a manual in English titled “Guide to introducing human rabies vaccine into national immunization programmes( /strong>Incorporating Human Rabies Vaccine into National Immunization Program Guidelines)” (see References), which comprehensively introduces WHO’s use of rabies vaccine and related issues in its main text and appendix authoritative answer. This blog will gradually introduce some of them for readers.
Rabies Surveillance
Surveillance systems are critical to rabies prevention and control and should be able to detect and monitor four events: animal bites, animal rabies , post-exposure prophylaxis (PEP) and human rabies. In an ideal system, all bites are detected and reported, all offending and suspicious animals are assessed, and all rabies PEPs are performed to appropriate protocols, resulting in a significant reduction in human rabies deaths or eliminate. The minimum requirement is that both human and animal rabies cases be reported nationwide (see Appendix 6 for a complete list of WHO minimum rabies indicators).
Human Rabies Surveillance
Human rabies surveillance relies on identification of suspected rabies cases, laboratory confirmation, and historical evaluation of cases. Local health care workers should be trained to identify suspected rabies cases. Any confirmed cases should be notified in accordance with national regulations.
Health care facilities offering PEP should be prepared to receive reports of suspected human rabies deaths and have procedures in place to ensure reporting to the appropriate animal and public health authorities. All suspected cases of rabies in humans should be investigated, even if the victim is deceased, because other members of the community and animals may not be aware that rabies exposure has occurred and require PEP.
Animal BiteInjuryMonitoring
Animal bites should elicit an immediate response, including appropriate observation or post-mortem testing when rabies is suspected. Prompt response by medical and veterinary staff can ensure proper case management and follow-up and increase case detection rates. The rules could also incentivize field and hospital staff to continue reporting cases.
Response should include timely feedback on case reports and diagnostic test results, and advice on case management and rabies control measures to be taken.
Determining community bite incidence is key to planning for rabies vaccine introduction and ongoing needs and assessing the effectiveness of rabies prevention and control programmes. In the absence of a robust surveillance system, regular community household surveys can be used to determine the incidence of bites and suspected rabies virus exposure.
These rates can be extrapolated to target populations and compared to bite treatment data to monitor improvements in medical seeking behavior and impact on human rabies mortality. Rabies vaccination coverage should be assessed at least annually.
Instance computing
Annual incidence of community bites * Proportion of bites suspected of exposure to rabies virus * Population in rabies vaccinated area = Estimated annual human rabies exposure.
Number of people initiated rabies post-exposure prophylaxis (PEP) / estimated annual human rabies exposure = rabies post-exposure vaccination coverage.
Dog bites occur frequently in most communities and are usually caused by interactions unrelated to rabies. Planning should not be concerned with whether the bite rate in the community is relatively constant – dog bite rates are not a good indicator of rabies virus transmission in the community.
Animal Rabies Surveillance
Healthy animals unrelated to human exposures are unlikely to contract rabies and should not be the focus of animal rabies surveillance systems. Focusing surveillance on animals with clinical signs consistent with rabies or in animals associated with human exposures often results in higher case detection rates, facilitates access to community support, and minimizes negative impacts on animal welfare, and make the project more cost-effective.
Veterinary professionals are most likely to encounter these animals and should therefore be involved in animal rabies surveillance. Animal rabies surveillance programs should consider the following factors:
• Estimate the number of animals that may be associated with rabies;
• Number of animals with rabies detected (ie suspected, probable, confirmed);
• Percentage of virus positive by laboratory test;
• Number of human exposures to rabies virus referred to healthcare facilities by veterinary professionals;
• Number of human exposures to rabies virus referred to veterinary professionals by healthcare facilities;
• Number of dogs vaccinated against rabies in vaccination areas;
• Percentage of rabies vaccination coverage in the dog population.
References:
World Health Organization. (2022). Guide to introducing human rabies vaccine into national immunization programs. World Health Organization. 29 July 2022, https://apps.who.int/iris/handle/10665/360978. License: CC BY-NC-SA 3.0 IGO.
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