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patient 1 was a 52-year - old woman with a history of hypertension who became ill on may 1 , 2014 , and was admitted to hospital a on may 11 with high fever ( temperature > 38c ) , cough , dyspnea , diarrhea , and anorexia .
her condition deteriorated , and she was transferred to an intensive care unit ( icu ) .
her condition remained poor , and on may 29 , 18 days after her symptoms began , she died of progressive respiratory failure .
patient 1 had not traveled to saudi arabia , but she had had close contact with a woman who had influenza - like illness and who had traveled to saudi arabia 2 weeks before her symptoms began .
this contact of patient 1 is suspected of being the index case - patient , but when throat swab and sputum samples were collected from her , she had no symptoms , and pcr results were negative .
a serum sample was not tested because serologic testing for mers - cov was not available .
patient 2 was the 50-year - old sister of patient 1 and also had a history of hypertension .
she became ill on may 11 , 2014 , with fever ( temperature > 38c ) , cough , hemoptysis , nausea , vomiting , and anorexia .
she was admitted to hospital a on may 17 ; her condition improved , and she was discharged on may 30 , 19 days after onset of symptoms .
patient 3 was a 35-year - old female nurse assistant at hospital a who had no underlying medical conditions .
her symptoms of sore throat and productive cough were detected on may 26 as part of the investigation of the first 2 cases ; co - infection with influenza a(h1n1)pdm09 was detected .
patient 3 was advised to stay home and follow infection control precautions until respiratory samples tested negative .
patient 4 was a 44-year - old male physician at hospital a with a history of chronic heart disease who had contact with patient 1 during her hospitalization in icu .
mild respiratory symptoms developed in patient 4 on june 6 ; his condition deteriorated , and he was admitted to a hospital in tehran , iran , on june 17 with fever ( temperature > 38c ) , sore throat , cough , dyspnea , chills , anorexia , and myalgia .
patient 4 s symptoms were initially severe , but his condition improved , and he was discharged on june 21 .
patient 5 was a 67-year - old woman who was admitted to hospital a on june 6 because of exacerbation of chronic obstructive pulmonary disease .
she was discharged from the hospital on june 14 and was in stable condition until severe acute respiratory infection ( sari ) developed .
she was readmitted to hospital a with fever ( temperature > 38c ) , cough , and dyspnea on june 25 . during her first hospitalization ,
the patient had close contact with another patient who had sari but had tested negative for mers - cov .
a respiratory sample from patient 5 was obtained on june 30 , and she died on july 5 .
all 5 patients were residents of kerman province and had no history of travel or contact with animals in the 14 days before becoming ill .
throat swab specimens and sputum samples were collected and analyzed by using real - time reverse transcription pcr ( rt - pcr ) performed on the basis of a previously reported method by targeting the upstream e region and open reading frame 1b of the virus ( 5 ) .
the samples from patients 1 , 2 , and 4 yielded n gene sequences positive for mers - cov .
phylogenetic analysis showed differences between these sequences and a consensus sequence retrieved from genbank ( accession no .
all 3 sequences from these cases had polymorphisms at positions 28880 ( tc ) , 28941 ( gc ) , and 29097 ( tg ) .
for the isolate from patient 4 , another nonsynonymous mutation was observed at position 29329 ( c to t ) , which resulted a change of tyrosine to isoleucine . in all 3 sequences ,
nucleotide c was detected at position 29147 , as was the case with the first identified isolate of mers - cov .
for some sequences in genbank , this position contains t.   phylogenic sequence analysis of 3 middle east respiratory syndrome coronavirus ( mers - cov ) isolates from patients in kerman province , iran ( boldface ) , 2014 , compared with sequences from genbank ( accession numbers shown ) .
mega 5.2 ( http://www.megasoftware.net ) was used for construction of neighbor - joining tree by using the kimura 2-parameter model with uniform rates and 1,000 bootstrap replicates .
we identified a cluster of mers - cov infections in iran ( table ) , showing apparent person - to - person transmission but with unclear transmission routes for some patients . in this cluster ,
patient 1 was in close contact with a person suspected of being the index case - patient , but we were unable to verify the infection status of this patient .
the source of infection for patients 3 and 4 was patient 1 or 2 , but the source for patient 5 s infection remains unknown .
however , subclinical cases of mers - cov infection have been reported to the world health organization ( 7 ) ; exposure to a person with subclinical infection could explain an active infection that has an unknown route of transmission .
throat swab specimens and sputum samples were collected from all close contacts of the 5 patients in this cluster , including family members , other patients in the hospital , and health care workers .
patient 1 had a pregnant daughter who was a frequent visitor during her hospitalization but who tested negative for mers - cov by real - time rt - pcr .  
before patient 1 was hospitalized , none of her contacts showed signs of mers - cov infection , but after her hospitalization ( during her second week of her illness ) , her sister became ill and subsequently tested positive for the virus .
this finding suggests that , as with severe acute respiratory syndrome , mers - cov is not readily transmitted during the early phases of the disease ( 3 ) , in contrast to the other human coronaviruses , which are transmitted early in the infection ( 2 )
. early recognition of confirmed mers - cov infections and investigation of the contacts of these patients are critical for effective epidemic control .
because saudi arabia has reported the highest number of mers - cov infections , one approach for limiting the transmission of this virus may be to screen travelers from iran who report sari to detect mers - cov .
however , screening of pilgrims from iran who traveled to mecca during the 2013 hajj did not detect mers - cov infections ( national influenza center iran , unpub .
first , some persons who may have had mers - cov infection were not tested , such as the probable index case - patient with whom patient 1 had contact , the patient with sari with whom patient 5 had contact , and the contacts of these persons .
second , we performed n gene pcrs on samples from all 5 case - patients , but results were negative for patients 3 and 5 , which suggests that these samples should be tested with more specific primers . in summary , we identified 5 cases of mers - cov in the same province in iran ; for several of these cases , virus transmission routes were not clearly defined .
future research should focus on clarifying routes of transmission for this virus , including the possibility of transmission from persons with subclinical infection .
during january 2013august 2014 , a total of 1,800 patients in iran who had respiratory illness were tested for middle east respiratory syndrome coronavirus . a cluster of 5 cases occurred in kerman province during may  
 july 2014 , but virus transmission routes for some infections were unclear .