Case Report: Failure of Therapeutic Coma in Rabies Encephalitis

Recent updates on laboratory diagnosis of rabies

Rabies is a lethal viral disease transmitted through the bite of rabid animals. India has a high burden of rabies, contributing to a significant proportion of the global deaths. However, under-reporting of the disease is prevalent due to lack of laboratory confirmation. Laboratory diagnosis of rabies plays a crucial role in differentiating the disease from clinical mimics, initiation of appropriate care, implementing infection control measures and informing disease surveillance. This review provides an overview of the recent advancements in laboratory diagnosis of rabies, aimed at updating physicians involved in diagnosis and management of rabies cases in India.

Case Report: Survival from Clinical Rabies in a Young Child from Maharashtra, India, 2022

A 3.5-year-old male child from Maharashtra, India, presented with features of meningoencephalitis approximately 1 month after sustaining severe bite injuries on the right hand from a stray dog. He had received four doses of post-exposure intradermal rabies vaccination (on days 0, 3, and 7 of the bite and erroneously on day 20, instead of day 28 as recommended in the updated Thai Red Cross regimen) as well as local and systemic injections of equine rabies immune globulin. The child was initially diagnosed with and treated for acute encephalitis syndrome before rabies encephalitis was confirmed by detection of rabies virus neutralizing antibodies in the cerebrospinal fluid. During the emergent period, he also received the antimalarial drug artesunate, recently reported to have antiviral effects against rabies virus. With intensive and supportive care, the child showed substantial clinical improvement over the next few weeks. He has now survived for more than 10 months after disease onset, albeit with severe neurological sequelae including diffuse cerebral and cerebellar atrophy.

Broad spectrum compounds targeting early stages of rabies virus (RABV) infection

ABMA and its analogue DABMA are two molecules of the adamantane family known to perturbate the endosomal pathway and to inhibit cell infection of several RNA and DNA viruses. Their activity against Rabies Virus (RABV) infection has already been demonstrated in vitro. (Wu et al., 2017, 2019). Here, we describe in more details their mechanism of action by comparison to Arbidol (umifenovir) and Ribavirin, two broad spectrum antivirals against emerging viruses such as Lassa, Ebola, influenza and Hantaan viruses. ABMA and DABMA, delivered 2 h pre-infection, inhibit RABV infection in vitro with an EC₅₀ of 7.8 μM and 14 μM, respectively. They act at post-entry, by causing RABV accumulation within the endosomal compartment and DABMA specifically diminishes the expression of the GTPase Rab7a controlling the fusion of early endosomes to late endosomes or lysosomes. This may suggest that ABMA and DABMA act at different stages of the late endosomal pathway as supported by their different profile of synergy/antagonism with the fusion inhibitor Arbidol. This difference is further confirmed by the RABV mutants induced by successive passages under increasing selective pressure showing a particular involvement of the viral G protein in the DABMA inhibition while ABMA inhibition induces less mutations dispersed in the M, G and L viral proteins. These results suggest new therapeutic perspectives against rabies.

Comparing clinical protocols for the treatment of human rabies: the Milwaukee protocol and the Brazilian protocol (Recife)

INTRODUCTION

Rabies is a major and seriously neglected public health problem worldwide. A treatment consisting of supportive therapy with the use of drugs that show antiviral activity is called the Milwaukee Protocol. In Brazil, this protocol was adapted to the national reality and called the Recife Protocol. In this study, we compared the Milwaukee Protocol with the Recife Protocol, assessing the differences and how these differences may change the course of clinical management.

METHODS

We searched electronic databases for the use of anti-rabies treatments. A total of 65 articles were published between 2004 and 2019.

RESULTS

The protocols have similarities in care related to rabies patients and are important for the treatment of patients in intensive care units. Both protocols indicate deep sedation, antiviral use, constant concern with electrolyte balance, and vasoconstriction related to the condition. Many differences were observed in this study. For the Milwaukee Protocol, sedation should be gradually removed after the eighth day, and on the twelfth day, the patient should be without sedation. In the Recife Protocol, in order to avoid immunomodulation, it is recommended to remove sedation according to the titers of neutralizing antibodies to the rabies virus in the cerebral spinal fluid.

CONCLUSIONS

In addition to the differences and similarities raised, our findings indicate that these protocols require a large center for rabies treatment, but the disease most often occurs in places where resources and hospital infrastructure are scarce.

Clinical features of rabies patients with abnormal sexual behaviors as the presenting manifestations: a case report and literature review

BACKGROUND

Abnormal sexual behaviors presenting as manifestations of rabies have occasionally been reported in the literature, although little attention has been paid to these cases to date. This study aimed to analyze the clinical features of rabies cases with abnormal sexual behaviors as the presenting manifestations.

CASE PRESENTATION

A case of 32-year-old man with frequent ejaculation as the initial symptom of rabies was first reported. Then, a literature review was conducted using databases including CNKI, SinoMed, VIP, Wanfang Data, ScienceDirect, ProQuest, OVID and PubMed. In addition to our case, 54 other rabies cases, with abnormal sexual behaviors as the presenting manifestations, have been reported since 1970. Among the 55 cases, 51 were male and three were female (unknown gender for one case), with ages ranging from 6 to 71 years. All cases were reported in developing countries, 46 in China. Dog bites were the major source of infection, and extremities were the main exposure sites. Overall, 46 (83.6%) cases had abnormal sexual behaviors as the initial symptoms. The major presenting manifestations were priapism and ejaculation in males and hypersexuality in females. All cases were clinically diagnosed based on medical history and clinical manifestations. Given no standardized post-exposure prophylaxis, all cases died with the survival time being between 1 and 15 days.

CONCLUSIONS

The rabies patients with abnormal sexual behaviors have unique clinical features. To avoid misdiagnosis, unexplained abnormal sexual behaviors should raise clinical suspicion of rabies.