31
ORIGINAL ARTICLE
Rabies Postexposure Consultations in New Zealand from 1998 to 2012 Marc T.M. Shaw, MD, DrPH,∗† Jenny Visser, MD, FRNZCGP,‡ and Ciaran Edwards§ Travellers Health Centres of New Zealand, Auckland, New Zealand; † School of Public Health, Tropical Medicine and Rehabilitation Sciences, James Cook University, Townsville, Australia; ‡ Primary Healthcare and General Practice, School of Medicine; § Wellington School of Medicine, University of Otago, Wellington, New Zealand
∗ Worldwise
DOI: 10.1111/jtm.12167
Background. Rabies is an invariably fatal zoonotic viral disease. New Zealanders going abroad are largely unaware of the risk of contracting the disease. Prevention is the key to controlling the spread of this disease. Methods. Data from 363 individuals presenting to New Zealand travel health clinics between 1998 and 2012 for post-travel consultations on potential rabies exposure were collated retrospectively. The data focused on traveler demographics, the country and nature of exposure, the purpose of travel, and pre-travel rabies awareness. Results. The female-to-male ratio of subject travelers presenting was almost equal (1.1 : 1 ratio, respectively); the subjects were typically between 16 and 30 years (44.6%), tourists (64.5%), traveling less than 1 month (55.3%), and likely to have been exposed to animal contact in either Thailand (31.1%), China (13.2%), or Indonesia (12.3%). The animals to which they were exposed were usually dogs (59.5%) or monkeys (28.7%). Most potential exposures were penetrating (69.9%). Injury caused by the animal was more common in the lower limbs (50%) than in the upper limbs (43.4%); 89.4% of exposures were of World Health Organization (WHO) category III. Travelers were more likely to have received pre-travel rabies advice if they had been seen by a travel medicine specialist (96.1%) compared to a general practitioner (GP) (53.3%). Sixteen percent of travelers received rabies preexposure prophylaxis. Of the subjects who were managed following exposure, 79.7% did not receive immunoglobulin when indicated, and 21.5% did not receive any vaccine. Of the travelers that did receive a vaccine, 62.5% did so on the day of exposure. Of the travelers assessed, 16.7% had traveled without insurance. Conclusions. New Zealanders require better guidance in understanding the need for travel-related rabies vaccination, as they are not managed abroad according to WHO guidelines. Few travelers had had pre-travel immunization, and only 20.3% of them had received WHO-advised postexposure management. Thus, 79.7% of the cohort theoretically remained at risk for contracting rabies because of inappropriate management following possible exposure to the disease.
amily infected after child bite in rabies horror.”1 A news article highlights the angst of rabies, a disease that remains all but treatable. “I held my breath when I heard that a child dying of rabies had bitten and infected his father and brother, it was horrific”: the emotive consequences of a possible exposure have an impact upon all involved, whether they be traveler or health professional. Rabies is an acute progressive fatal encephalitis caused by neurotropic RNA viruses of the family Rhabdoviridae, genus Lyssavirus.2,3 There are 13 “
F
Corresponding Author: Marc Shaw, MD, DrPH, Worldwise Travellers Health Centres of New Zealand, 12c St Marks Road, Newmarket, Auckland 1050, New Zealand. E-mail: [email protected]
recognized or proposed lyssaviruses4 estimated to cause at least 55,000 human rabies-related deaths worldwide each year, a figure likely greatly underestimated, mostly in Asia and Africa.5 Studies have indicated that New Zealanders may be overrepresented in travel-related potential rabies exposures6,7 and these from a virus that is classically transmitted via a skin-penetrating mammalian bite. Notwithstanding this typical manner of transmission, it can variably occur by way of mucous membranes or saliva-contaminated scratches. Reports of transmission via aerosols or via transplantation of an infected organ are rare.5,8 Increased global travel to unusual and entrancing destinations has escalated the risk of exposure to animal-related injuries.9 Although all mammalian exposure is potentially suspect, carnivores and bats act as reservoirs, with over 98% of fatal cases being © 2014 International Society of Travel Medicine, 1195-1982 Journal of Travel Medicine 2015; Volume 22 (Issue 1): 31–38
32
attributable to infected dog bites.10 In many regions of the world where the risk of rabies is high, access to standard World Health Organization (WHO)-asserted postexposure prophylaxis (PEP) is very limited and, therefore, it is not surprising that cases of fatal imported rabies have recently been reported in travelers.9 In fact, 22 deaths have been reported in returning travelers in the last decade.11 Information about the risk of rabies for travelers to tropical countries, and recommendations for the use of preventive measures may be neglected in the pre-travel advice provided by health care practitioners. There is a lack of knowledge about the risk of acquiring rabies during a journey to countries endemic for the disease, and this has led primary health care practitioners to neglect providing relevant information to travelers.12 – 14 The incidence of injuries to travelers caused by potentially rabid animals has been estimated to be 0.4% per month of stay13 whereas the risk of acquiring fatal rabies following exposure to a rabid animal is reported to vary from a low of 0.1% in persons experiencing non-bite exposures to a high of 60% in persons with penetrating wounds or hand or face lesions.15 It is estimated that over 10 million people are exposed to potentially rabid animals annually.16 While the true incidence will, in all likelihood, never be known, the figure of two cases per year is a simplicity that gives only a small indication as to the prevalence of the disease in travelers.13 Prompt and appropriate postexposure treatment, including the use of rabies immunoglobulin (RIG) and rabies vaccine, virtually eliminates rabies fatalities.17 Over a billion travelers cross international borders each year,18 and much of this travel is to resource-poor rabies-endemic countries where access to optimal postexposure care is often limited.17,19 The Pacific Basin Region, Oceania, Papua New Guinea, New Zealand (NZ), and Australia are rabies-free (although the Australian bat lyssavirus has been isolated from insectivorous and fruit-eating bats in the country and has caused human fatalities).20,21 GeoSentinel (a collaborative surveillance program between the CDC and the International Society of Travel Medicine) previously assessed animal bites in New Zealanders returned from travel. They found that nearly 1 in 10 of the post-travel group sought advice on such exposure, this being the highest rate, per capita, of any of the travelers assessed at any of the GeoSentinel sites.7 This could, in part, be due to subsequent GeoSentinel data reflecting an epidemiological survey of animal-related injuries where patients with animal-related injuries were significantly more likely to have traveled to South-East Asia and South Central Asia than those with other travel-associated diagnoses, these being significant travel destinations for New Zealanders.22 Fortunately, there have been no cases of rabies infection recorded in NZ to date, but given the severity of the infection, a closer look at patients presenting to NZ travel clinics following possible exposure to the J Travel Med 2015; 22: 31–38
Shaw et al.
disease could provide better information on both the risks of rabies infection and rabies postexposure management. The only circumstance where rabies postexposure follow-up and prophylaxis would be required in NZ is when a traveler, or itinerant, presents to a clinic there after a potential exposure in an endemic country. The management of PEP is well established, with set principles of management.23 – 25 Based on this set of criteria, we studied the risk factors for rabies exposure and the treatment received by international travelers who subsequently presented for care in NZ travel health clinics after a potential rabies contact. The hypothesis upon which this study was built was that the management of travelers following rabies exposure does not meet WHO recommendations. This study includes data from a previous work on rabies management in NZ,6 and was extended from the latter study to provide a richer and more comprehensive data set and analysis of rabies risk factors and postexposure management reported to NZ travel health clinics between 1998 and 2012. The extrapolation of this information is anticipated to provide a rationalization of both pre-travel health preparation and post-travel management policy in NZ. Patients and Methods All patients presenting to dedicated travel health clinics in NZ between October 1998 and November 2012 for consideration of postexposure rabies management, including prophylaxis, following a potential exposure to rabies infection during travel, were included in this study. Ethics Approval for this study was granted by University of Otago. Medical records, over 15 years, from two NZ nation-wide travel health franchises (“Worldwise Travelers Health Centres” and “The Travel Doctor”) and two independent travel health clinics in Auckland were screened for consultations on rabies postexposure management. While the target population was primarily identified as New Zealanders who had traveled overseas to rabies-endemic regions, it also included non-NZ-resident travelers who had traveled to rabies-endemic regions as well as to NZ during the same period of travel. Where possible (not all medical centers collected data over the same time span, and data from some clinics were incomplete) the data extracted included the following: 1 The initial NZ clinic of management. 2 Patient demographics (age, gender, country of residence). 3 Whether pre-travel health consultation had occurred and if it had discussed rabies preexposure prophylaxis (PrEP). 4 The trip duration and location of possible exposure to rabies. 5 The animal involved (animal species, type, whether it had been provoked, whether the location where
Rabies Postexposure Consultations in New Zealand
6 7 8
9
the exposure occurred was urban or rural, rabies vaccination status, and whether a 10-day mammal observation period was observed). The nature of exposure (type of injury and WHO categorization, body part exposed). Rabies preexposure vaccination status. The postexposure management overseas and in NZ (if there was a record of treatment, wound toilet, rabies immune globulin and vaccine administration, time from the initial lesion to medical management, and finally whether tetanus vaccine and antibiotics were administered). The presence or absence of travel health insurance.
These data was entered in tabulated form into a Microsoft Excel sheet. Prevalence was calculated using OpenEpi software. Confidence intervals for estimates were calculated as follows: for proportions, Fisher’s exact confidence interval was used; confidence intervals for rates were calculated using the Delta method. Results A total of 363 patients with a history of rabies exposure and management were included in this 15-year study. Complete data for each patient were not extractable from some medical records because of data input and variability in clinic records; thus, assessment of all subject cases was made using the available information. Patient data sets were collected from 15 travel health centers. Nearly half (45.7%) of the patient data were collected between 2010 and 2012 (3 years); see Figure 1. Gender and Age There were 51.8% females [95% confidence interval (CI) 42.9–53.5%] and 48.2% males (95% CI 46.5–57.1%) with a 1.1 : 1 female-to-male ratio in the 361 of 363 records noting gender. A total of 350 patient records recorded patient age: the average age of travelers was 34 years, the median age was 29 years (range: 1–80 years). The age distribution is shown in Table 1. Country of Residence Seventy-seven percent (95% CI 76.1–85.5%) of 281 patients whose residency status was recorded and who had presented to travel clinics for rabies PEP were NZ residents. NZ residents of Chinese ethnicity constituted 11.4% (95% CI 7.59–16.26%) of these patients. Fifty-four patients were non-NZ residents (including 28 from Europe, 10 from China, and 6 from North America). Pre-Travel Experience From the 306 available records, it was found that only 16% (95% CI 12.1–20.6%) of patients had pre-travel rabies PrEP. Of a total of 177 travelers, 50.8% (95% CI 43.2–58.4%) reported having had a pre-travel consultation and 73 of these reported seeing either a
33
travel medicine specialist or a general practitioner (GP): 78.1% of this number (95% CI 66.9–86.9%) saw a travel medicine specialist, who was more likely (96.1%; 95% CI 86.5–99.5%) to discuss rabies than a GP (53.3%; 95% CI 26.6–78.7%), P < 0.05. Location of Exposure Of the 363 patients in the data set, country exposure data were available for 357. China, South and South-East Asia were the most common geographical regions where exposure had occurred, with a total of 244 (68%) subjects being potentially exposed to rabies in these regions. The 10 countries that accounted for 85.4% of exposures were Thailand, 111 (31%); China, 47 (13%); and Indonesia, 44 (including Bali, 34) accounting for 12% of exposures; India, 37 (9.3%); Vietnam, 18 (5%); Cambodia, 14 (4%); Philippines, 10 (3%); South Africa, 9 (2.5%); Sri Lanka, 8 (2.2%); and Tanzania, 7 (2.0%). Trip Duration The average trip duration was 155.4 days and the median trip length was 28 days (range: 5–1,095 days). Of the 78 of 141 subjects who recorded their trip duration, 55.3% were away for less than a month, and 36 (25.5%) were away for 1 to 6 months; thus, 80.8% of trips were less than 6 months in duration. Eight of the 141 (5.7%) subjects were away for 6 to 12 months and 19 (13.5%) were away for more than a year. Reason for Travel Among the 259 patients for whom data were available, the top three reasons for travel were tourism, 167 (64.5%); “Visiting Friends and Relatives” (VFR), 43 (16.6%); and missionary/volunteering work, 22 (8.5%). Other reasons for travel are noted in Table 2. Animals Involved In 348 of the 363 records, the animals involved were recorded: of these, dogs were responsible for the majority of exposures (59.5%), followed by monkeys (28.7%), and then cats (8.3%). In 176 of the total records, it was possible to ascertain if the animal was domestic or wild, or a stray. Of these, 57.7% of animals were recorded as being domestic, 34.1% as being wild, and 10.2% were noted as being stray. The location where the exposure had taken place was recorded in 139 of the 363 cases. Of these, 60.4% of potential rabies exposures were reported to have occurred in urban locations compared to 39.6% in rural settings. Where recorded, only 15.3% (95% CI 9.8–22.5%) of 124 patients had noted an exposure as being provoked. A total of 18 travelers reported that they had been able to observe the offending animal for 10 days. Only 5 of 133 travelers had incidents where the animal was tested. Three results were reported as positive, but no objective information was given as to how they were tested. Table 3 lists animals that possibly provoked the rabies virus exposure. J Travel Med 2015; 22: 31–38
34
Shaw et al.
Figure 1 Rabies exposure patient medical records per year. *45.7% of patient data from 2010 to 2012. Table 1
Age distribution of travelers exposed to rabies
Age group (years) n %
0 to 15
16 to 30
31 to 45
46 to 60
61+
Total
34 9.7%
156 44.6%
75 21.4%
58 16.6%
27 7.7%
350
Table 2 Reason for travel of those patients potentially exposed to rabies virus
Table 4
WHO rabies exposure category
WHO category Reason for travel Tourism VFR (visiting friends and relatives) Missionary/volunteer work Business Resident Research Total
Table 3
n
%
167 43 22 13 11 2 258
64.5 16.6 8.5 5.0 4.2 0.8
Animal provoking possible rabies virus exposure
Animals*
n
%
95% CI
Dog Monkey Cat Other Bat Squirrel Total
207 100 29 12 5 2 355
59.5% 28.7% 8.3% 3.0% 1.4% 0.6%
54.1% to 64.7% 24.0% to 33.8% 5.7% to 11.7% 0.8% to 4.1% 0.5% to 3.3% 0.1% to 2.1%
CI, confidence interval. *Other animals include coati, tiger, lion, raccoon, and squirrel.
In the 4 years prior to the Bali rabies outbreak of 2008, 24.3% (95% CI 16.7–33.4%) of consultations on possible rabies exposure were monkey-related, compared to the 4 years since 2008 when this figure had risen significantly to 31.6% (95% CI 25.3–38.3%) monkey-related exposure consults. Nature of Exposure The majority of contacts with potential for rabies infection were penetrating wounds, which were thus classed J Travel Med 2015; 22: 31–38
I II III Total
n
%
95% CI
1 33 286 320
0.3% 10.3% 89.4%
0.0% to 1.7% 7.2% to 14.2% 85.5% to 92.5%
CI, confidence interval; WHO, World Health Organization.
as WHO Category III exposures. The sites of exposure were recorded in 290 of 363 patients: of these, in descending order, the thigh and lower leg, 145 (50.0%; 95% CI 44.1–55.9%); the upper limb, 126 (43.4%; 95% CI 37.7–49.4%); the head, 12 (4.1%; 95% CI 2.2–7.1%); and the trunk, 7 (2.4%; 95% CI 1.0–4.9%), were the more common body sites involved. A significant subset of exposures, involving the upper limb, was the hand, being involved in 28.6% (95% CI 23.5–34.2%) of cases. The categories of animal exposures in 320 of the 363 noted subjects were WHO graded as Category I (1, 0.3%), Category II (33, 10.3%), Category III (286, 89.4%), and unknown (2, 3.7%) (Table 4). PEP Management Data on the performance of wound toilet in the country of potential exposure was available in the case of 177 travelers. Of these subjects, 153 (86.4%, 95% CI 80.5–91.1%) had received first aid wound care, although there was no indication of how appropriate this had been. Of the cohort of 363, 321 (88%) had information on whether they had had PEP: 252 (78.5%; 95% CI 73.6–82.9%%) had received vaccine in the country of exposure, and the remaining 69 (21.5%; 95% CI 17.1–26.4%) had not received an appropriate WHO
Rabies Postexposure Consultations in New Zealand
vaccine while they were away. The average time to PEP, based on 206 of 363 patient records, was 32 days (range: 0–1,826 days) whereas the median time to PEP was
ORIGINAL ARTICLE
Rabies Postexposure Consultations in New Zealand from 1998 to 2012 Marc T.M. Shaw, MD, DrPH,∗† Jenny Visser, MD, FRNZCGP,‡ and Ciaran Edwards§ Travellers Health Centres of New Zealand, Auckland, New Zealand; † School of Public Health, Tropical Medicine and Rehabilitation Sciences, James Cook University, Townsville, Australia; ‡ Primary Healthcare and General Practice, School of Medicine; § Wellington School of Medicine, University of Otago, Wellington, New Zealand
∗ Worldwise
DOI: 10.1111/jtm.12167
Background. Rabies is an invariably fatal zoonotic viral disease. New Zealanders going abroad are largely unaware of the risk of contracting the disease. Prevention is the key to controlling the spread of this disease. Methods. Data from 363 individuals presenting to New Zealand travel health clinics between 1998 and 2012 for post-travel consultations on potential rabies exposure were collated retrospectively. The data focused on traveler demographics, the country and nature of exposure, the purpose of travel, and pre-travel rabies awareness. Results. The female-to-male ratio of subject travelers presenting was almost equal (1.1 : 1 ratio, respectively); the subjects were typically between 16 and 30 years (44.6%), tourists (64.5%), traveling less than 1 month (55.3%), and likely to have been exposed to animal contact in either Thailand (31.1%), China (13.2%), or Indonesia (12.3%). The animals to which they were exposed were usually dogs (59.5%) or monkeys (28.7%). Most potential exposures were penetrating (69.9%). Injury caused by the animal was more common in the lower limbs (50%) than in the upper limbs (43.4%); 89.4% of exposures were of World Health Organization (WHO) category III. Travelers were more likely to have received pre-travel rabies advice if they had been seen by a travel medicine specialist (96.1%) compared to a general practitioner (GP) (53.3%). Sixteen percent of travelers received rabies preexposure prophylaxis. Of the subjects who were managed following exposure, 79.7% did not receive immunoglobulin when indicated, and 21.5% did not receive any vaccine. Of the travelers that did receive a vaccine, 62.5% did so on the day of exposure. Of the travelers assessed, 16.7% had traveled without insurance. Conclusions. New Zealanders require better guidance in understanding the need for travel-related rabies vaccination, as they are not managed abroad according to WHO guidelines. Few travelers had had pre-travel immunization, and only 20.3% of them had received WHO-advised postexposure management. Thus, 79.7% of the cohort theoretically remained at risk for contracting rabies because of inappropriate management following possible exposure to the disease.
amily infected after child bite in rabies horror.”1 A news article highlights the angst of rabies, a disease that remains all but treatable. “I held my breath when I heard that a child dying of rabies had bitten and infected his father and brother, it was horrific”: the emotive consequences of a possible exposure have an impact upon all involved, whether they be traveler or health professional. Rabies is an acute progressive fatal encephalitis caused by neurotropic RNA viruses of the family Rhabdoviridae, genus Lyssavirus.2,3 There are 13 “
F
Corresponding Author: Marc Shaw, MD, DrPH, Worldwise Travellers Health Centres of New Zealand, 12c St Marks Road, Newmarket, Auckland 1050, New Zealand. E-mail: [email protected]
recognized or proposed lyssaviruses4 estimated to cause at least 55,000 human rabies-related deaths worldwide each year, a figure likely greatly underestimated, mostly in Asia and Africa.5 Studies have indicated that New Zealanders may be overrepresented in travel-related potential rabies exposures6,7 and these from a virus that is classically transmitted via a skin-penetrating mammalian bite. Notwithstanding this typical manner of transmission, it can variably occur by way of mucous membranes or saliva-contaminated scratches. Reports of transmission via aerosols or via transplantation of an infected organ are rare.5,8 Increased global travel to unusual and entrancing destinations has escalated the risk of exposure to animal-related injuries.9 Although all mammalian exposure is potentially suspect, carnivores and bats act as reservoirs, with over 98% of fatal cases being © 2014 International Society of Travel Medicine, 1195-1982 Journal of Travel Medicine 2015; Volume 22 (Issue 1): 31–38
32
attributable to infected dog bites.10 In many regions of the world where the risk of rabies is high, access to standard World Health Organization (WHO)-asserted postexposure prophylaxis (PEP) is very limited and, therefore, it is not surprising that cases of fatal imported rabies have recently been reported in travelers.9 In fact, 22 deaths have been reported in returning travelers in the last decade.11 Information about the risk of rabies for travelers to tropical countries, and recommendations for the use of preventive measures may be neglected in the pre-travel advice provided by health care practitioners. There is a lack of knowledge about the risk of acquiring rabies during a journey to countries endemic for the disease, and this has led primary health care practitioners to neglect providing relevant information to travelers.12 – 14 The incidence of injuries to travelers caused by potentially rabid animals has been estimated to be 0.4% per month of stay13 whereas the risk of acquiring fatal rabies following exposure to a rabid animal is reported to vary from a low of 0.1% in persons experiencing non-bite exposures to a high of 60% in persons with penetrating wounds or hand or face lesions.15 It is estimated that over 10 million people are exposed to potentially rabid animals annually.16 While the true incidence will, in all likelihood, never be known, the figure of two cases per year is a simplicity that gives only a small indication as to the prevalence of the disease in travelers.13 Prompt and appropriate postexposure treatment, including the use of rabies immunoglobulin (RIG) and rabies vaccine, virtually eliminates rabies fatalities.17 Over a billion travelers cross international borders each year,18 and much of this travel is to resource-poor rabies-endemic countries where access to optimal postexposure care is often limited.17,19 The Pacific Basin Region, Oceania, Papua New Guinea, New Zealand (NZ), and Australia are rabies-free (although the Australian bat lyssavirus has been isolated from insectivorous and fruit-eating bats in the country and has caused human fatalities).20,21 GeoSentinel (a collaborative surveillance program between the CDC and the International Society of Travel Medicine) previously assessed animal bites in New Zealanders returned from travel. They found that nearly 1 in 10 of the post-travel group sought advice on such exposure, this being the highest rate, per capita, of any of the travelers assessed at any of the GeoSentinel sites.7 This could, in part, be due to subsequent GeoSentinel data reflecting an epidemiological survey of animal-related injuries where patients with animal-related injuries were significantly more likely to have traveled to South-East Asia and South Central Asia than those with other travel-associated diagnoses, these being significant travel destinations for New Zealanders.22 Fortunately, there have been no cases of rabies infection recorded in NZ to date, but given the severity of the infection, a closer look at patients presenting to NZ travel clinics following possible exposure to the J Travel Med 2015; 22: 31–38
Shaw et al.
disease could provide better information on both the risks of rabies infection and rabies postexposure management. The only circumstance where rabies postexposure follow-up and prophylaxis would be required in NZ is when a traveler, or itinerant, presents to a clinic there after a potential exposure in an endemic country. The management of PEP is well established, with set principles of management.23 – 25 Based on this set of criteria, we studied the risk factors for rabies exposure and the treatment received by international travelers who subsequently presented for care in NZ travel health clinics after a potential rabies contact. The hypothesis upon which this study was built was that the management of travelers following rabies exposure does not meet WHO recommendations. This study includes data from a previous work on rabies management in NZ,6 and was extended from the latter study to provide a richer and more comprehensive data set and analysis of rabies risk factors and postexposure management reported to NZ travel health clinics between 1998 and 2012. The extrapolation of this information is anticipated to provide a rationalization of both pre-travel health preparation and post-travel management policy in NZ. Patients and Methods All patients presenting to dedicated travel health clinics in NZ between October 1998 and November 2012 for consideration of postexposure rabies management, including prophylaxis, following a potential exposure to rabies infection during travel, were included in this study. Ethics Approval for this study was granted by University of Otago. Medical records, over 15 years, from two NZ nation-wide travel health franchises (“Worldwise Travelers Health Centres” and “The Travel Doctor”) and two independent travel health clinics in Auckland were screened for consultations on rabies postexposure management. While the target population was primarily identified as New Zealanders who had traveled overseas to rabies-endemic regions, it also included non-NZ-resident travelers who had traveled to rabies-endemic regions as well as to NZ during the same period of travel. Where possible (not all medical centers collected data over the same time span, and data from some clinics were incomplete) the data extracted included the following: 1 The initial NZ clinic of management. 2 Patient demographics (age, gender, country of residence). 3 Whether pre-travel health consultation had occurred and if it had discussed rabies preexposure prophylaxis (PrEP). 4 The trip duration and location of possible exposure to rabies. 5 The animal involved (animal species, type, whether it had been provoked, whether the location where
Rabies Postexposure Consultations in New Zealand
6 7 8
9
the exposure occurred was urban or rural, rabies vaccination status, and whether a 10-day mammal observation period was observed). The nature of exposure (type of injury and WHO categorization, body part exposed). Rabies preexposure vaccination status. The postexposure management overseas and in NZ (if there was a record of treatment, wound toilet, rabies immune globulin and vaccine administration, time from the initial lesion to medical management, and finally whether tetanus vaccine and antibiotics were administered). The presence or absence of travel health insurance.
These data was entered in tabulated form into a Microsoft Excel sheet. Prevalence was calculated using OpenEpi software. Confidence intervals for estimates were calculated as follows: for proportions, Fisher’s exact confidence interval was used; confidence intervals for rates were calculated using the Delta method. Results A total of 363 patients with a history of rabies exposure and management were included in this 15-year study. Complete data for each patient were not extractable from some medical records because of data input and variability in clinic records; thus, assessment of all subject cases was made using the available information. Patient data sets were collected from 15 travel health centers. Nearly half (45.7%) of the patient data were collected between 2010 and 2012 (3 years); see Figure 1. Gender and Age There were 51.8% females [95% confidence interval (CI) 42.9–53.5%] and 48.2% males (95% CI 46.5–57.1%) with a 1.1 : 1 female-to-male ratio in the 361 of 363 records noting gender. A total of 350 patient records recorded patient age: the average age of travelers was 34 years, the median age was 29 years (range: 1–80 years). The age distribution is shown in Table 1. Country of Residence Seventy-seven percent (95% CI 76.1–85.5%) of 281 patients whose residency status was recorded and who had presented to travel clinics for rabies PEP were NZ residents. NZ residents of Chinese ethnicity constituted 11.4% (95% CI 7.59–16.26%) of these patients. Fifty-four patients were non-NZ residents (including 28 from Europe, 10 from China, and 6 from North America). Pre-Travel Experience From the 306 available records, it was found that only 16% (95% CI 12.1–20.6%) of patients had pre-travel rabies PrEP. Of a total of 177 travelers, 50.8% (95% CI 43.2–58.4%) reported having had a pre-travel consultation and 73 of these reported seeing either a
33
travel medicine specialist or a general practitioner (GP): 78.1% of this number (95% CI 66.9–86.9%) saw a travel medicine specialist, who was more likely (96.1%; 95% CI 86.5–99.5%) to discuss rabies than a GP (53.3%; 95% CI 26.6–78.7%), P < 0.05. Location of Exposure Of the 363 patients in the data set, country exposure data were available for 357. China, South and South-East Asia were the most common geographical regions where exposure had occurred, with a total of 244 (68%) subjects being potentially exposed to rabies in these regions. The 10 countries that accounted for 85.4% of exposures were Thailand, 111 (31%); China, 47 (13%); and Indonesia, 44 (including Bali, 34) accounting for 12% of exposures; India, 37 (9.3%); Vietnam, 18 (5%); Cambodia, 14 (4%); Philippines, 10 (3%); South Africa, 9 (2.5%); Sri Lanka, 8 (2.2%); and Tanzania, 7 (2.0%). Trip Duration The average trip duration was 155.4 days and the median trip length was 28 days (range: 5–1,095 days). Of the 78 of 141 subjects who recorded their trip duration, 55.3% were away for less than a month, and 36 (25.5%) were away for 1 to 6 months; thus, 80.8% of trips were less than 6 months in duration. Eight of the 141 (5.7%) subjects were away for 6 to 12 months and 19 (13.5%) were away for more than a year. Reason for Travel Among the 259 patients for whom data were available, the top three reasons for travel were tourism, 167 (64.5%); “Visiting Friends and Relatives” (VFR), 43 (16.6%); and missionary/volunteering work, 22 (8.5%). Other reasons for travel are noted in Table 2. Animals Involved In 348 of the 363 records, the animals involved were recorded: of these, dogs were responsible for the majority of exposures (59.5%), followed by monkeys (28.7%), and then cats (8.3%). In 176 of the total records, it was possible to ascertain if the animal was domestic or wild, or a stray. Of these, 57.7% of animals were recorded as being domestic, 34.1% as being wild, and 10.2% were noted as being stray. The location where the exposure had taken place was recorded in 139 of the 363 cases. Of these, 60.4% of potential rabies exposures were reported to have occurred in urban locations compared to 39.6% in rural settings. Where recorded, only 15.3% (95% CI 9.8–22.5%) of 124 patients had noted an exposure as being provoked. A total of 18 travelers reported that they had been able to observe the offending animal for 10 days. Only 5 of 133 travelers had incidents where the animal was tested. Three results were reported as positive, but no objective information was given as to how they were tested. Table 3 lists animals that possibly provoked the rabies virus exposure. J Travel Med 2015; 22: 31–38
34
Shaw et al.
Figure 1 Rabies exposure patient medical records per year. *45.7% of patient data from 2010 to 2012. Table 1
Age distribution of travelers exposed to rabies
Age group (years) n %
0 to 15
16 to 30
31 to 45
46 to 60
61+
Total
34 9.7%
156 44.6%
75 21.4%
58 16.6%
27 7.7%
350
Table 2 Reason for travel of those patients potentially exposed to rabies virus
Table 4
WHO rabies exposure category
WHO category Reason for travel Tourism VFR (visiting friends and relatives) Missionary/volunteer work Business Resident Research Total
Table 3
n
%
167 43 22 13 11 2 258
64.5 16.6 8.5 5.0 4.2 0.8
Animal provoking possible rabies virus exposure
Animals*
n
%
95% CI
Dog Monkey Cat Other Bat Squirrel Total
207 100 29 12 5 2 355
59.5% 28.7% 8.3% 3.0% 1.4% 0.6%
54.1% to 64.7% 24.0% to 33.8% 5.7% to 11.7% 0.8% to 4.1% 0.5% to 3.3% 0.1% to 2.1%
CI, confidence interval. *Other animals include coati, tiger, lion, raccoon, and squirrel.
In the 4 years prior to the Bali rabies outbreak of 2008, 24.3% (95% CI 16.7–33.4%) of consultations on possible rabies exposure were monkey-related, compared to the 4 years since 2008 when this figure had risen significantly to 31.6% (95% CI 25.3–38.3%) monkey-related exposure consults. Nature of Exposure The majority of contacts with potential for rabies infection were penetrating wounds, which were thus classed J Travel Med 2015; 22: 31–38
I II III Total
n
%
95% CI
1 33 286 320
0.3% 10.3% 89.4%
0.0% to 1.7% 7.2% to 14.2% 85.5% to 92.5%
CI, confidence interval; WHO, World Health Organization.
as WHO Category III exposures. The sites of exposure were recorded in 290 of 363 patients: of these, in descending order, the thigh and lower leg, 145 (50.0%; 95% CI 44.1–55.9%); the upper limb, 126 (43.4%; 95% CI 37.7–49.4%); the head, 12 (4.1%; 95% CI 2.2–7.1%); and the trunk, 7 (2.4%; 95% CI 1.0–4.9%), were the more common body sites involved. A significant subset of exposures, involving the upper limb, was the hand, being involved in 28.6% (95% CI 23.5–34.2%) of cases. The categories of animal exposures in 320 of the 363 noted subjects were WHO graded as Category I (1, 0.3%), Category II (33, 10.3%), Category III (286, 89.4%), and unknown (2, 3.7%) (Table 4). PEP Management Data on the performance of wound toilet in the country of potential exposure was available in the case of 177 travelers. Of these subjects, 153 (86.4%, 95% CI 80.5–91.1%) had received first aid wound care, although there was no indication of how appropriate this had been. Of the cohort of 363, 321 (88%) had information on whether they had had PEP: 252 (78.5%; 95% CI 73.6–82.9%%) had received vaccine in the country of exposure, and the remaining 69 (21.5%; 95% CI 17.1–26.4%) had not received an appropriate WHO
Rabies Postexposure Consultations in New Zealand
vaccine while they were away. The average time to PEP, based on 206 of 363 patient records, was 32 days (range: 0–1,826 days) whereas the median time to PEP was
