In 2003, a 43-year-old white woman who had undergone a pulmonary lobectomy during childhood underwent bilateral lung transplantation because of severe chronic respiratory failure caused by bilateral bronchiectasis. The posttransplant period was complicated by bronchiolitis obliterans syndrome stage 1, with episodes of acute respiratory distress. The immunosuppressive regimen included tacrolimus (through level 10–15 ng/mL), low-dose steroids (0.10 mg/kg/day), and monthly courses of extracorporeal photopheresis that were initiated after a 3-month course of low-dose azythromycin (discontinued because of lack of efficacy).

In January 2012, the patient’s respiratory condition worsened and she was hospitalized. She had cough and fever (38°C), abdominal cramps, and diarrhea (6–10 bowel movements/day, liquid but not bloody). Routine fecal examination and cultures were negative for common gastrointestinal bacteria (Mycobacteria, Salmonella, Shigella, and Campylobacter spp.), parasites (protozoa and helminths), and viruses (astrovirus, norovirus, rotavirus, adenovirus). Because of the patient’s persistent gastrointestinal symptoms and a positive fecal calprotectin result, a colonoscopy was performed; it revealed inflamed cecal mucosa without ulcerative lesions. Histologic examination of colonic biopsy samples showed mild, chronic, interstitial inflammation, including eosinophils and lymphoid microaggregates. Therefore, fecal samples were examined for less common gastroenteric viral agents—rhinovirus, bocavirus, enterovirus, parechovirus, coronavirus, sapovirus, aichivirus and HCoSV—by using conventional and real-time PCR or nested reverse transcription PCR (RT-PCR) (1,7–14). Samples were negative for all gastrointestinal viruses searched for except for HCoSV. This virus was detected by a nested RT-PCR targeting the 5′ untranslated region (UTR) (1) and quantified on the basis of serial log₁₀ dilution of extracted nucleic acid estimating the presence of 10⁷ RNA copies/mL in fecal samples. The 316-bp 5′ UTR amplicon was sequenced by using an ABI Prism 3100 DNA automatic sequencer (Applied Biosystems, Foster City, CA, USA), assembled by Sequencer software, version 5.0 (Gene Codes Corporation, Ann Arbor, MI, USA), and compared with available HCoSV sequences with the BLAST program (http://blast.ncbi.nlm.nih.gov). Nucleotide identity with the HCoSV species D (species D1) (GenBank accession no. FJ438908) was 93%.

Figure

Figure. . Maximum-likelihood tree based on viral protein (VP) 3–VP1 sequences. Bootstrap values were set for 1,000 repetitions and were placed over each main node of the tree. Bootstrap values <70% are...

Because the 5′ UTR is not sufficiently discriminatory for typing, we sequenced the highly variable region encompassing VP3–VP1 genes, obtained according to a published protocol (6). Phylogenetic analysis, performed with the maximum-likelihood method with parameters selected by the Model Selection tool in MEGA version 5.0 (15), showed that the HCoSV VP3–VP1 sequence from Italy clustered with species E strains found in Australia and Bolivia and recombinant D/E strains circulating in Nigeria. Although homology was greatest (97% nt and 81% aa identity) with a strain from Australia (GenBank accession no. FJ555055) (Figure), the hypothesis that this HCoSV strain might be a D/E recombinant strain (6) cannot be excluded because the recombination breakpoint between VP1 and the 2A gene was not investigated.

To define the circulation of HCoSV in northern Italy, we retrospectively tested 689 stored fecal samples for HCoSV positivity by using the same nested RT-PCR (1). The samples had been collected during April 2011–April 2012 from patients hospitalized at our hospital with gastrointestinal signs and symptoms. Of these 689 patients, 333 (48.3%) were adults (230 [69.0%] immunocompetent and 103 [31.0%] immunocompromised) and 356 (51.7%) were children (275 [77.2%] immunocompetent and 81 [22.8%] immunocompromised). Surprisingly, none of these samples were positive for HCoSV.

In the absence of specific therapy, the patient reported here underwent parenteral rehydration and nutritional supplementation; her general condition improved progressively, and her bowel movements were reduced to 2–3 per day, enabling her to be discharged within a month. However, her gastrointestinal symptoms persisted, and 3 fecal samples collected at 4, 6, and 7 months after discharge were positive for the same HCoSV strain (at a high titer of 10⁵–10⁷ virus RNA copies/mL feces) but negative for other viruses, bacteria, and parasites.

We reported identification of HCoSV in the Mediterranean area. The infection was detected in 1 of 689 patients with gastrointestinal symptoms who were hospitalized and tested during the same period. Unique to this patient were the prolonged immunosuppressive therapy and the chronic gastrointestinal symptoms with persistently HCoSV-positive fecal samples. The persistence of symptoms and virus are additional new findings that might be associated with the patient’s immune impairment.

The source of infection has not been determined. However, the patient denied domestic or international travel and close contact with persons returning from travel. Because no other HCoSV infection was detected in patients hospitalized at the same institution during the same period, we hypothesize that the infection was acquired in the patient’s community before her hospitalization. The genetic similarity with E strains circulating in South America, Australia, and Central Africa suggest local acquisition of an imported infection. However, additional evidence is required before excluding the potential autochthonous circulation of HCoSV in northern Italy.