2008 August | Protecting Endangered Mountain Gorillas

Urwunguko Sick: Lethargy, Runny Nose, and Cough

Category: Monitoring Visits | Date: Aug 11 2008 | By: Dr. Lucy for gorilladoctors

Kabatwa and her infant Urwunguko rest in the sun; both are recovering from the outbreak of respiratory disease in the Hirwa Group, Rwanda.

I’ve been back in Rwanda for several weeks. As always, I spent two of them in self-imposed quarantine. Any time one of the vets travels on an airplane, we risk exposure to infectious diseases carried by fellow travelers. Though I wash my hands often and stay away from people who appear sick, it’s impossible to eliminate the risk. Since most viral and bacterial infectious have a week to 10-day incubation period, we spend at least two weeks office-bound. It’s a time to focus on administrative work and deal with paperwork.

Muninya, the Hirwa Group silverback, is fully recovered two weeks after treatment for a severe bout of respiratory illness.

While I worked at my desk, Magda, Jean Felix, and Elisabeth kept me updated on the field situation in Rwanda. They continued to check on two family groups of gorillas sick with respiratory disease. Group 13 had an easier time of it, with milder symptoms—some nasal discharge and a few coughs. The outbreak in Hirwa Group was more serious. The silverback Muninya recovered quickly after treatment with antibiotics but the illness continued to spread slowly among the others. The sickest gorillas included four females, all with offspring ranging in age from one- to one-and-a-half years old. So far, only one infant, Urwunguko, hadshown any real signs of illness, and at last report he was recovering.

Hirwa Group gorillas, recovering from respiratory illness, rest during a brief period of sunshine.

I visited Hirwa Group on my first day back in the forest. Magda had just left for Nwyungwe National Park, where she’d been invited to work with the trackers there on chimpanzee identification and health monitoring, Jean Felix needed a day in the office, and Elisabeth was off on vacation. I knew to expect lethargy, runny noses, and loud coughs. Even so, when I first heard a series of low-pitched grunting sounds, it took me a few seconds to recognize the noise as a coughing gorilla. When we found the group still hunkered in their night nests I shouldn’t have been surprised. Respiratory disease makes tracking the gorillas easy. You can hear them coughing from quite a distance, and they rarely move far from one day to the next.

Sabana, an adult female in Hirwa Group, regained her appetite after several days of lethargy and cough.

I watched and listened as one of the adult females, Sabana, coughed repeatedly. She lay curled on her side, still in her night nest. Her infant, Umuranga, sat next to her, playing with a few leaves, waiting for his mother to move. The lead tracker for the day, Majoro, told me that Sabana had just started eating again yesterday. Four other gorillas coughed somewhere in the surrounding vegetation. We later identified them as the females Mararo, Ntamehezu, Ikerezi, and Magayane. Sabana’s cough sounded the worst, so much so that I found myself stopping in my tracks to look in her direction each time she started up. It’s an awful feeling to know these rare animals might be sick from a disease we humans unknowingly passed on to them. Definitive proof of such transmission still lies ahead in the analysis of the data we’re slowly collecting. But we know from recent studies in habituated, free-living chimpanzees that human respiratory viruses can infect wild great apes, making them sicker than their own naturally circulating viruses.

Urwunguko clings to his mother, breathing with his mouth open to compensate for a stuffy nose.

We found Kabatwa and her thirteen-month-old infant, Urwunguko (pronounced Urunn gu gwu kwo) foraging apart from the group. Kabatwa coughed lightly a few times, picked her nose with one hand, and continued feeding with the other. She appeared unphased by her illness. Urwunguko clung to her quietly, his nose running. He held his mouth open, breathing through it rather than through his congested nostrils. Magda, Jean Felix, and Elisabeth later confirmed later that this infant had had a nasal discharge for over a week. The color—white—was a good sign. Yellow to green snot is a sign of serious bacterial infection. Even so, Urwunguko’s history put him in the category of at-risk-for-pneumonia, and I planned to return the next day.

Urwunguko and his mother, Kabatwa, rest together.

Early the next morning, we found three Hirwa Group females and their infants still in their nests, Mararo, Sabana, and Kabatwa. All were coughing–Sabana again louder than the others. White mucous streamed from Kabatwa’s nostrils. She licked her nose and picked at the discharge with one hand, while grooming Urwunguko with the other. He sat motionless, eyes droopy, nose runny with a yellowish-white discharge. He seemed less alert than the day before. Uh-oh, I thought, wondering if the infection–which we generally believe to be viral at first and bacterial later on–was going down into his lungs. We agreed the trackers would watch him closely all day.

As I left, I tried not to over-think this case. I thought back to Ururabo and her baby during the Susa Group respiratory disease outbreak in May. The day Ururabo felt too sick to hold and groom her infant had been the day it weakened and had trouble breathing. It was also the day we intervened. In this case, not only is Kabatwa taking good care of Urwunguko, he’s a full year older than Ururabo’s baby. If he continues to nurse and she continues to keep him warm and dry, he’ll probably be okay.

Ntamuhezu, recovering from respiratory disease, and her still healthy infant, Agasaro, waking up early one morning, Hiwra Group, RW.

We know the gorillas feel better and improve more rapidly after antibiotic therapy, but we don’t treat them unless absolutely necessary. We certainly don’t want to risk creating resistant bacteria, among other things. The decision to intervene is always a judgment call. Our goal, which is also our mandate, is to intervene on Urwunguko’s behalf only if his condition becomes life-threatening. The trouble is that young apes—or humans—with signs of upper respiratory disease can suddenly develop a life-threatening infection deep down in the lungs. Urwunguko is also just small enough that darting him with medicine might be too much of a challenge, meaning we’d have to anesthetize the mother as well. The good thing is that we can check him each day. That’s our job.

Urwunguko resting on his mother’s back, breathing rapidly.

The next morning as we headed into the forest, Majoro told me he’d seen the infant nursing well yesterday afternoon. But when we reached the group, the situation appeared to have worsened. Urwunguko had a runny nose, and his eyelids were swollen and wrinkled. He seemed to want to do nothing except sleep. Moreover, he was tachypneic—his breathing rate was elevated at 100 or more breaths per minute. (Normal is 30-40 breaths per minute for a gorilla of his size.) After the sun came out and the other infants began to play, he hung on to his mother and continued to sleep. When Kabatwa got up to eat, though, he climbed on her back and looked more alert. I left thinking I’d better bring the medical kit the next day.

Kabatwa grooming her infant, Urwunguko, who is sick with lethargy, a runny nose, and nasal discharge.

The report that afternoon was encouraging. Majoro again observed the infant nursing and spending a few minutes sitting next to its mother, rather than clinging to her. Given how quickly pneumonia can kill young primates—humans included—I decided to bring the kit the next morning anyway. Once again we found Kabatwa still in her nest. Majoro and I watched anxiously for several minutes as Urwunguko slept in her arms. His breathing rate was better, down to 60-70 breaths per minute range, but his upper lip was covered with crusty yellowish dry nasal discharge. Finally, he woke up, stretched, opened his eyes wide, picked his nose, and then coughed several times, a wet-sounding cough. Kabatwa grunted as if to tell him not to make that noise. Despite the cough, my worry level went down, at least for this day. As Kabatwa groomed her infant, he fiddled in her lap, a normal behavior. Urwunguko’s tiny leg and arm muscles were definitely small targets for a dart of antibiotics. Were we to intervene, we’d have to anesthetize the mother, too.

Urwunguko, a thirteen-month old mountain gorilla, is improving after two weeks of illness with respiratory disease, Hirwa Group, RW.

I brought the kit one more time the next day, anticipating that the infant would either be much better or in big trouble. To our relief, we found him nibbling on bits of plant material and sitting several feet away from his mother. Though he coughed several times, his eyes and nose were clear. Kabatwa looked at me sideways, tolerating my presence, as usual. I don’t really believe she has a clue about who I am; still, I found myself saying to Majoro, as if he could understand my English, “She’s probably wondering why the doctor keeps showing up and what in the world I’ve been so worried about.”